December 5th, 2014 by

Net Zero Energy and Net Zero Water buildings have rapidly captured the public imagination, and are transforming expectations for the pace of change in the built environment. We’re excited to attend Net Positive’s Energy and Water Conference to explore these concepts this January 22 – 23rd, 2015. Keynotes Jason McLennan, Sandra Postel, and Steven Strong will make for an exciting event.

Come join and let us know if you’ll be there!

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Rapid Urbanization in Dubai

September 25th, 2013 by

Dubai is experiencing the most startling and rapid urbanization seen in current day. In the past 25 years alone, Dubai has transformed from a small Middle Eastern city into a global market with a skyline rivaling New York.

With such rapid urbanization, questions about the environmental impact of development and the structural integrity of buildings have risen. Due to the desert climate, The United Arab Emirates needs to desalinize water and has a heavy use of air conditioning – economic and environmental factors such as these have been compounded by the recent boom in construction and development in Dubai.

Screen shot 2013-09-18 at 3.35.12 PM

Urbanization has occurred so quickly that proper planning has not been completed- for example, until 2010, a single water waste treatment plant treated nearly 17 million cubic feet of waster daily, nearly twice the size the plant was designed to hold and properly treat.

All at the same time, construction continued for hundreds of skyscrapers with little regard for environmental standards. With easy access to an abundance of resources, construction within Dubai was made cheap and easy. However, like all natural recourses, once reserves were depleted, there was not an inexpensive way to obtain more. Since then there has been a large shift in thinking. New regulations now dictate all construction, energy consumption, and water usage in the city. In the summer of 2010 a large water waste treatment facility was erected with the capacity to treat the more waste daily than entirety of the other facility’s overflow.

Despite efforts, creating a sustainable city in a desert is challenging. Urbanization requires an abundance of energy that Dubai is struggling to find. The easiest option would be turning to nuclear power, but that process is hardly sustainable itself, using large amounts of water and producing radioactive waste.

Instead, Dubai has turned to creating some of the most structurally unique buildings seen to date. A rotating skyscraper, powered by wind turbines placed between each floor is scheduled to be built in the heart of Dubai. Not only does the building harness enough energy to power itself, but the surplus generated powers five other buildings of the same size.

Known as the “Dynamic Tower,” this apartment complex is entirely self-sufficient. Image from:

Known as the “Dynamic Tower,” this apartment complex is entirely self-sufficient.
Image from:

Dubai is also home to the world’s tallest building, Burj Khalifa. Standing over 2000 feet tall, this building Burj Khalifa is so tall it was constructed with GPS tracking to monitor that the sway to ensure it is no more than 12 feet in any direction. With 163 floors, the building is used as a hotel, apartment building, and corporate office building.

The tallest building in the world compared to the previous tallest buildings in the world and other dominating world skyscrapers.
Image from:

While these two structures alone are impressive, it is the overall skyline that makes Dubai breathtaking. Dozens of other structurally unique buildings have been constructed including the infinity tower and structure, alone on an island, built to look like a sailboat. The skyline may be impressive now, but as urbanization continues to boom one can only imagine what the city may look like ten years down the road.

Dubai skyline in 2013. Photo by drmerlin Image found:

Dubai skyline in 2013. Photo by drmerlin
Image found:

Similar to Dubai, Abu Dhabi, the second largest city in The United Arab Emirates, is also experiencing rapid urbanization. Though less know than Dubai, Abu Dhabi also has a beautiful skyline with many buildings unlike any other in the world. Sherwood Design Engineers helped develop a green building rating system for Abu Dhabi called The Pearl Rating System. Specifically, Sherwood developed the water calculator for the community rating system and helped write all the Stormwater credits. The methodology used in the Pearl Rating System is similar to that of LEED certification but awards up to 5 pearls for sustainable building development practices. This new system came into fruition in tandem with a movement to plan and build new structures in Abu Dhabi by 2030 to create a skyline to rival Dubai.

Abu Dhabi Skyline Image by gianmarco giudici, found:

Abu Dhabi Skyline
Image by gianmarco giudici, found:

These two dominating cities in The United Arab Emirates are experiencing unprecedented urbanization in the structural development each city is experiencing. Structurally unique buildings already form breathtaking skylines and more urbanization and construction is still to come. With these plans, the UAE is taking impressive initiative to build green and sustainable structures.

Acid Mine Drainage

May 28th, 2013 by

The following post is authored by student and Sherwood blogging intern, Stephanie Merenbach.

As in many countries, the demands for potable water in South Africa are increasing. City populations are on the rise due to urbanization as people move out of rural villages and into the city centers of the nation. The population shifts are causing an increase in the amount of potable water needed each day. For many, the lure to the city is not only the promise of better education and jobs, but also the overall improvement in quality of life. Many people still in villages acquire water from local wells or streams, which comes at little to no cost to the state, but as the city population grows, the amount of water needed to be available in the city is ever increasing. There is not only a water shortage, but the water currently available is highly susceptible to water borne disease and contamination. One of the main reasons for this contamination is the South African gold mining industry.

Deep gold mining has continued to prosper as a leading industry in the South African economy. Mines which are burrowed 4km underground account for the largest source of unmined gold and fuel the South African economy. The US Geological Survey estimates that South Africa has the largest portion of the world’s gold reserves (almost 50%), with approximately 6,000 metric tons of the metal.


gold mine

This expansive gold mine, known as Igoli, The Place of Gold, is in Gauteng, the smallest but most urbanized province of South Africa. Similar gold mines, which expand across hundreds of acres of land and have tremendous environmental repercussions, are found all across South Africa.
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Acid mine drainage is caused when the iron sulfur pyrite, released from the mine reacts with water and air to create sulfuric acid and dissolved iron. The iron is highly noticeable through a reddish orange residue left on the rock, soil, and anything else that comes in contact with the contaminated water. In addition to the qualitative changes, the sulfuric acid causes a significant decrease in the pH of the water compared with the standard 7 pH of pure water. Depending on the location, the water may also contain toxic heavy metals and radioactive particles.

Due to the importance of the gold mining industry to the local and global economy it is very hard to change the mining practices. Nonetheless, acid mine drainage is recognized as one of the most environmentally hazardous impacts of a mine.

Acid Mine Drainage is visible through the orange sediments contaminating water downstream of mines allowing untreated runoff back into the environment. Picture from:

Acid Mine Drainage is visible through the orange sediments contaminating water downstream of mines allowing untreated runoff back into the environment.
Picture from:

There could be an opportunity to use ground water extracted in the mining process for drinking water with proper procurement and purification. However, at this time it is not possible because of how heavily the mining process contaminates the runoff. To make matters worse, many mining companies are not taking proper precautions to prevent this water from entering nearby streams, further contaminating potential drinking water.

Acid mine drainage is not a new issue in South Africa. Evidence of such contamination has been easily visible since mining first began due to the orange residue left behind by oxidized iron from the water. Unfortunately, much damage is already done. Increased amounts of Uranium have entered the water table making the land as well as the water toxic to humans. Uranium remains radioactive for hundreds of thousands of years. Therefore, the only option left in some contaminated areas is relocating the inhabitants.

All hope is not lost though when it comes to moving forward and supplying water to the citizens of South Africa. It is important to bring this issue to the forefront so that proper measures can be taken to stop further destruction of an increasingly valuable natural resource, water.

Some strategies to help minimize the negative effects of gold mining include stopping the flow of contaminated water and neutralizing (raising) the pH of the water back to 7 before releasing the water into the environment. If the flow of contaminated water is stopped, not only will the water flowing downstream into the cities be potable, but it also opens up more options to create safe wells that will not be affected by the runoff.


Waste runoff down stream from gold mines polluted and untreated by gold mining corporations.  Image from:

Waste runoff down stream from gold mines polluted and untreated by gold mining corporations.
Image from:

In theory, it sounds simple: stop the runoff and the problem is solved. But like most issues in today’s world, economics are preventing forward movement towards a solution. Treating and purifying the water exiting the mine before releasing it will cost the mining companies a lot. These are the same companies that fuel the South African economy and the world’s gold mining industry. In any way disturbing the gold mining process and productivity could have huge implications on the nation’s economy and currency rates, not to mention that these companies have huge influence with the government, thereby preventing policies which could work towards environmental sustainability.

At some point new policies will need to be put in place to prevent the contamination of mine water runoff. The large mining corporations are not going to make these changes on their own. Policy is needed to drive this change to protect the local population rather than the corporations. For now, we hope to spread the message in hopes that the lawmakers see the need for a change in policy before the people of South Africa run out of drinkable water entirely.

Michael Thorton: Skoll Centre for Social Entrepreneurship

September 13th, 2012 by

Michael Thornton is spending the year at Oxford University as a Skoll scholar. This is one of the most prestigious honors at Oxford and distinguishes Michael from his peers. This success is a result of his tireless ambition in advancing the evolution of sustainable infrastructure on his work globally. Michael is in England for the year focusing on getting his MBA and preparing himself for creating greater social impact in his future endeavors. The Skoll Centre for Social Entrepreneurship is a leading global entity for the advancement of social entrepreneurship. They foster innovative social transformation through education, research, and collaboration. The Skoll Foundation drives large scale change by investing in, connecting and celebrating social entrepreneurs and the innovators who help them solve the world’s most pressing problems. Way to go Michael!

Details here.

New Bangalore Lakes Project Video

October 10th, 2011 by

Check out the new video for the Sherwood Institute’s Bangalore Lakes Restoration Project! The full video can be viewed here.

The project page also has more information about the project’s background and ways that you can get involved to help.

Opinions about the development of the environmental protection industry during the 12th FYP period

June 20th, 2011 by

In the conference proceedings of the 12th International Environmental Protection Exhibition and Conference which occurred earlier this month, there was included a very nice analysis of China’s 12th Five Year Plan (2011-2015) as it relates to the environmental protection industry, written by the  China Association of Environmental Protection Industry (CAEPI).  It includes some history on the environmental protection industry in China, future trends for development, and most importantly China’s environmental industry development within the context of the 12th Five Year Plan, which is a policy guidance document which sets the goals for the next five years for the country.

6 Main Task Areas for the environment are identified in the analysis. In order, they are:

  1. Water Pollution Prevention and Treatment
  2. Air Pollution Prevention and Treatment
  3. Solid Waste Treatment and Disposal
  4. Noise and Vibration Control
  5. Environmental Monitoring
  6. Environmental Services Industry

You can download both the original Chinese article and my (unofficial) English translation of the document below.

Click here to download original Chinese version (pdf)

Click here to download English translation (pdf)

Lake Dian, in Yunnan Province suffers from eutrophication and is one of the main lakes designated for remediation by the 12th Five Year Plan

12th China International Environmental Protection Exhibition and Conference

June 14th, 2011 by

From June 7-June 10, the 12th China International Environmental Protection Exhibition and Conference (CIEPEC) was held in Beijing. The exhibition and conference, which are held every two years, are one of the major opportunities for enterprises, academia, and regulators from China and internationally to exchange ideas and solutions for China’s environmental issues.  The aim of the exhibitions closely follow the main goals laid out by China’s Five Year Plans (FYP).

The exhibits and conferences were free and open to the public and received media attention

This year, being the first year of the 12th FYP, the exhibition dedicated one full floor to summarize the progress made during the 11th FYP (2006-2010) through text, photos, models, and technology demostration, and to set goals for the 12th FYP (2011-2015). This year’s CIEPEC was hosted at the China International Exhibition Center, with over 30,000 square meters of exhibition space, organized into six exhibition halls, two of which were dedicated to stalls for international companies. In total, over 500 domestic and international companies were represented.  International exhibition areas were organized by Italy, France, the US, Germany, Japan, Korea, Canada, Holland, Beligum and Israel.

Two halls were dedicated to international firms' exhibition to promote international collaboration around China's environmental issues

Exhibits addressed the following themes: Pollution control technologies, environmental monitoring and analysis, clean production and resource utilization, ecological remediation and protection, environmentally-friendly products and technologies, and the environmental service sector. Though more emphasis is being placed on the development of the environmental services sector in the 12th FYP, these firms represented a minority of the exhibits, indicating opportunity for international firms to transfer techniques to the Chinese market. The majority of exhibits focused on wastewater treatment techniques and environmental monitoring instruments.

An exhibit at the 12th China International Environmental Protection Exhibition and Conference

The conference proceedings handbook also contained a document entitled “Opinions about the development of the environmental protection industry during the 12th Five-Year Plan period”, which features expert analysis of China’s Environmental Protection Industry in the context of development as outlined by the 12th FYP. There is currently no English version available for this document, but I will shortly be posting my translation of the document for reference.

China’s Five Year Plans: Importance and Implementation

May 30th, 2011 by

China’s Five Year Plans (FYP) are important documents that China uses to direct the overall goals of the governance of the country. They are like blueprints for economic and social growth and industrial planning in key sectors. Although most people refer to the FYPs as a single document, in actually they represent a complex collection of government documents, including previously-implemented development plans and hundreds of policy initiatives, all of which are constantly being revised during the five year circle that they are meant to guide. As a kind of summarizing document, the FYP serves as a overarching vision of the state of the country. Studying the documents relating to the most current FYP is important not only to government officials, legislators, and state-run enterprises; the content of the FYPs will influence the amount of government spending in certain sectors and framing one’s goals within those of the country is prudent for private business, Chinese and international, as well.

The 12th Five Year Plan was discussed at the Fourth Session of the Eleventh National People’s Congress. Source:

The first FYP was made for the period 1953-1957, so 2011 is the first year in the 12th cycle of FYPs. In the previous few months, there was much discussion on the implementation success of the 11th FYP, which will influence the content and implementation techniques for the 12th FYP. Since this blog address environmental issues, I will try to speak about the FYPs’ implementation as they relate to China’s environment.

The implementation of the last year of the 11th FYP (2006-2010), was discussed in depth on March 5, 2011 at the Fourth Session of the Eleventh National People’s Congress and a report (available in English) was prepared by the National Development and Reform Commission (NDRC). The summary included six points that were reported on:

  1. Steady and rapid economic growth was maintained
  2. The agricultural foundation was consolidated
  3. Economic restructuring was carried out vigorously
  4. Significant progress was made in energy conservation and environmental protection and in responding to climate change.
  5. Reform and opening up were further intensified.
  6. Efforts to ensure and improve the people s wellbeing were comprehensively strengthened.

Of these six, three are particularly relevant to the environment. The “agricultural foundation” that was consolidated in the second point refers to the three issues of rural areas, agricultural production, and farmers’ livelihoods. Water conservation is a big issue in agriculture. Currently, China not only needs to worry about food production for a rapidly growing urban population, but it also has to think about water conservation practices that will make food production more sustainable with the highest possible efficiency. In 2010, according to the NDRC report, the Central Government successfully formulated and carried out policies to intensify the construction of small and medium-sized water conservancy facilities. In addition, because public works in rural areas is generally also lagging behind urban areas, the living conditions of the rural population was also a big issue in 2010. The NDRC reported stated that in 2010 safe drinking water was provided to an additional 61.9 million rural residents than in 2009.

Volunteers test water quality in a rural area. In 2010, safe drinking water was provided to an additional 61.9 million rural residents than in 2009.

The second point that is of interest is economic restructuring. This point relates to the industrial and infrastructure plans that support the economic growth policies included in the first point. Low-efficiency “backward” production facilities were targeted for shut-down, including low capacity thermal power plants, steel mills, iron foundries, cement plants, plate glass plants, and paper mills. Shutting down small industries will allow the central government to better regulate contaminant emissions from industry, and to ensure that growth is happening in the most efficient way possible. In addition, this section also reported on massive infrastructural work that China accomplished during this period.

Nationwide, 4,986 kilometers of railway lines were put into operation, raising the total to 91,000; 120,000 kilometers of highways were opened to traffic, raising the total to 3.98 million; 500 kilometers of high-grade inland waterways were opened to navigation, raising the total to 10,000; 125 deepwater seaport berths were put into service, raising the total to 1,774; and 9 new civilian airports were put into service, raising the total to 175. Some 1.66 million kilometers of optical cables were installed, raising the total to 9.95 million kilometers; and 49.24 million broadband Internet access ports were opened up, raising the total to 188 million. We intensified the construction of key energy projects, energy bases, and storage and transportation facilities. Eleven out of 13 large coalmining bases have already reached a production capacity of 100 million tons.

To support economic restructuring, 4,986 kilometers of railway lines were put into operation in China during the 11th FYP. Some of these lines cut through environmentally sensitive areas. Photo source: Xinhua News Agency

Lastly, the point on environmental protection and energy conservation stated that all targets for energy targets and emissions reductions were met. These included installation of high-efficiency air conditioning units, and promotion of energy-efficient vehicles, and energy-saving light bulbs. The reported stated that through the implementation of 10 major national energy conservation projects, the energy equivalent of 33.1 million tons of standard coal was saved. Resource reuse was demonstrated through mineral recovery bases in urban areas. In 2010, 76.9% of urban sewage was treated, an increase of 1.6 percentage points from the previous year, and 72.5% of urban household waste was safely handled, an increase of 1.2 percentage points from 2009. Energy consumption, chemical oxygen demand, and sulfur dioxide emissions all met or exceeded the goals set by the 11th FYP during the period from 2006-2010. Several specific remediation and reforestation projects were also mentioned, including the grassland remediation, virgin forest protection projects, and remediation of long-time problem areas, such as Dianchi Lake, and Tai Lake. According to the report, implementation had positive results. Lastly in this point, climate change was mentioned. The central government effectively implemented China’s National Climate Change Program. Successes in international exchanges and cooperation for improvement in low-carbon technology was emphasized.

After summarizing the achievements of the 11th FYP and the work accomplished in 2010, there are six problems listed which are designated as “serious conflicts and problems facing domestic development”. The first problem listed is the issues relating to agriculture and rural development. Insufficient farmland and freshwater scarcity, poor water conservancy infrastructure, uncertainties over climate change, and generally low levels of agricultural science and technology will continue to be major constraints to agriculture and rural development that will have to be addressed. Another point within the six problems mentioned is that resource and environmental constraints have intensified. Energy usage and resource consumption is increasing too quickly and the level of major contaminant emission is too high. Energy-intensive and high-pollution industries are continuing to grow too quickly.

Small cement production facilities contribute to contaminant emissions and thus have been designated for shut-down by the Five Year Plans.

From the NDRC document, it is evident that there are possibly a few areas where expertise in sustainable design and green infrastructure will be very important. Civil engineering can be used in overall masterplanning to improve local hydrology in agricultural areas and water quality and supply in urban and rural areas. Energy conservation can be accomplished through applying guidelines such as those suggested by LEED in new buildings and communities. The transfer of these techniques that are more common in the United States and other developed countries to the Chinese environment is an area with an enormous amount of potential to make vast improvements.

My Research at Tsinghua University

May 26th, 2011 by

Perhaps a few readers will be interested in the research that I have been doing over the past few years at Tsinghua University, located in Beijing, China. Tsinghua University is considered to be one of the best universities in China, also sometimes known as the MIT of China. I have been doing research in the Persistent Organic Pollutants Research Group of the School of Environment for the past two years.

Old gate of Tsinghua University, Beijing China, established in 1911

School of Environment, Tsinghua University

Persistent Organic Pollutants (POPs) are chemical contaminants which exhibit persistent, bioaccumulative, and toxic properties in the environment. They also have long distance transport potential and therefore have been found to exist in remote areas, such as the Arctic, where they accumulate in the fat, blood and inner organs of animals such as polar bears. The Stockholm Convention on POPs was signed in 2001 and put into effect in 2004, as an international accord to reduce and eliminate the use and production of designated POPs. The original convention took place in 2001 as a response to a call from the United Nations Environment Programme (UNEP) to take action on POPs, and included a list of the “Dirty Dozen” chemicals, which were designated as the “worst offender” chemicals. In 2009, a second set of 9 chemicals were added as the “new POPs”. China is a party to the Stockholm Convention, and thus has shown commitment to eliminating the production and use of the listed POPs.

Molecular structure of PFOS, one of the "new POPs" as designated by the Stockholm Convention for its persistent, bioaccumulative, and toxic properties

My research focused on one of the “new POPs”, called perfluorooctanesulphonate (PFOS), which is a fully fluorinated eight carbon chain with a sulfonic acid head. Because this chemical is both oleophobic and hydrophobic (exclusion of both non-polar oils and polar water), it was historically used as a surfactant and coating for many products, including fabrics and carpeting. The most common product utilizing PFOS was produced by 3M, and called Scotchgard™. In addition, it is commonly used as a processing aid in industries including metal plating, and paper treatment, and as a key ingredient in aqueous fire-fighting foams (used to combat fires fueled by highly flammable gases or liquids).

In 2000, 3M, then the largest producer of the parent compound Perfluorooctane sulfonyl fluoride (POSF), announced the discontinuation of all its PFOS-related products because of the chemical’s toxicity to humans and the environment. Shortly thereafter, most other countries followed suit and banned the production of the chemicals. However, because of a lack of appropriate substitutes and technical transfer, China continues to be the only country still reported to be producing POSF and utilizing PFOS, despite its entrance into the Stockholm Convention.

Relatively speaking, China has only produced a small amount of POSF compared to 3M, however, there the true effects of this contaminant are still not determined because of incomplete emissions inventory, which is typically needed to be able to assess a contaminant’s effect in a certain region. Mostly, there is no existing, complete centralized record of exactly which industries are still utilizing PFOS. The first part of my research was to determine the key areas in China for which more investigation investment would be likely to contribute the most emission of PFOS into the environment. I designed a emissions inventory methodology specific to the contamination patterns of PFOS in the Chinese environment that grouped lifetime product releases into wastewater treatment plant effluents, while determining key industries for further investigation. Wastewater treatment effluent concentrations were determined to exhibit a correlation with more easily-obtainable geo-referenced data, such as population density and city GDP. This way, an estimate of PFOS emission can be extrapolated without having to test every city’s wastewater effluents.

A schematic for the emissions scenario I designed for back calculating source load from environmental concentrations

While designing the emissions inventory methodology, I found that China-specific industrial data and emissions factors are greatly lacking, but that environmental monitoring concentrations are much more available for a wide range of areas within China. Therefore, utilizing these environmental concentrations, I developed a unique multimedia fugacity model to estimate source load in a given area, given PFOS’ physical-chemical properties and the hydrological conditions of the modeled area. I completed a case study example and successfully proved my model’s stability for a segment of the Huangpu River in Shanghai.

In addition, also using the available environmental monitoring concentrations, I also carried the first national probabilistic risk assessment for PFOS in China. Probabilistic risk assessment is different from deterministic risk assessments, which have been performed in the past, in that it is able to incorporate spatial and temporal variability. Based on toxicity data reported in the literature, I also derived a predicted no effect concentration range (PNEC) by which to evaluate the conservativeness of previously reported PNEC values.

Me, at the 100th Anniversary Celebration of Tsinghua University at the Great Hall of the People, Beijing, China

Me and Yang Liwei, first Chinese taikonaut in space at the 100th year anniversary of Tsinghua University at the Great Hall of the People, Beijing, China

I enjoyed my two years at Tsinghua University. Aside from my research, I participated in many of my research group’s and school activities. This year was the 100th Anniversary of the founding of the university, and I was chosen as a representative of the School of Environment to attend the celebration at the Great Hall of the People, where President Hu Jintao (alumus of Tsinghua University Hydraulic Engineering) spoke, along with the presidents of Tsinghua University, Peking Univeristy, Yale University and student and faculty representatives. This year was also the first year that The Department of Environmental Science and Engineering became the School of Environment, an event that represents the growing importance of environmental issues in China and the country’s commitment to training the country’s best and brightest to help solve some of China’s most pressing environmental challenges.

Old Summer Palace: Example of Chinese Public Involvement in Environmental Issues

May 24th, 2011 by

The Old Summer Palace is one of the “must sees” for both Chinese and international visitors to Beijing. Historically, the 860 acres, comprised of the Garden of Perfect Brightness, the Garden of Eternal Spring, and the Elegant Spring Garden has been known as the “Garden of Gardens” in Chinese for its once exquisite collections of stone palaces, landscaping, waterscaping and artwork. After the looting and burning of the site by British and French troops in 1860 during the Opium War however, the ruins of the Old Summer Palace still represent the shame of many Chinese feel from foreign imperialist forces in China’s modern history. The importance of the site is unquestionable, both for international visitors and for Chinese.

Ruins of the Old Summer Palace in Beijing, China

Thus, when Chinese environmental activist and visiting professor at Lanzhou University, Zhengchun Zhang posted an open letter was on the Internet in 2005, exposing park officials’ plans to line the gardens’ lake beds with plastic to prevent lakes’ water from being lost through infiltration into the underlying groundwater, a storm of public outrage erupted. Although the plan to seal the lakebed was made in the good interest of the preservation of the Old Summer Palace’s waterfront aesthetics, it was exposed that the plan, which had an estimated cost of 3.6 million US dollars, did not undergo any environmental impact assessment, an approval required by law before any construction begins.

The decision to line the beds of the lakes within the Old Summer Palace with plastic came from the park administration. Beijing is one of the thirstiest cities in the world, with a per capita water resource amount of only one-thirtieth the international average. Falling groundwater levels have also caused surface water to infiltrate more quickly into the ground so that for the lakes such as those in the Old Summer Palace, surface water levels also fall. Because rainwater is also scarce, replenishment of the lake took place artificially, putting extra burden on the city’s already-strained municipal water supply. With no action, the water has to be added into the lakes three times per year; with the planned liners, they only have to be artificially replenished once per year. Preventing loss of water from infiltration to the underlying groundwater would be able to maintain water levels for the flora and fauna dependent on the lakes.

A worker covers an impermeable plastic membrane with soil in the bed of a lake in the Old Summer Palace. Source: Xinhua News Agency

However, opponents of the plan debated fiercely through both online and traditional media outlets. The plan was reminiscent of many other projects to line canals and riverbeds with cement, which began in the 1990’s in Beijing and contributed new ecological challenges. Hard-facing water bodies eliminates interaction between water and the underlying sediment, a crucial part of the ecosystem balance. It also changes the overall hydrology. In summer months, concrete –surfaced lakes heats faster than sediment and accelerates evaporation. The flows between water bodies could also be disrupted, and could change some areas into “dead water”, or even accelerate flow out of the site. Although the plan for the Old Summer Palace called for plastic liners, possible toxic effects of such liners on the ecosystem were not evaluated in any way. Others said that the surface water bodies within the park also constitute historical marsh areas which recharge the areas groundwater levels. Without evaluation, the effects of cutting off such a such of groundwater replenishment were unknown.

Because of the amount of attention the project garnered through online discussion forums and traditional media, the first-ever national level environmental public hearing was called by the National State Environmental Protection Agency (SEPA, now the Ministry of Environmental Protection). This was the first time that environmental governance was spurred through pressure from the general public rather than from regulatory officials, and thus, was a milestone in China’s environmental democratization.

As a result, Tsinghua University’s Environmental Impact Assessment (EIA) Office was called upon to carry out a public report on the site, which at the time of the public hearing, already neared completion. This report was assembled by a team of university experts and made the following recommendations:

1.       The eastern portion of the site should not carry out further sealing using the plastic membrane, and that natural clay material should be used to reduce infiltration.

2.       The plastic membrane installed at the mouth of Elegant Spring Garden should be removed and replaced with clay filling and the original sediment of the lake. The banks of the lake should not utilize any sealing membrane.

3.       The areas of Eternal Spring Garden lake higher than 40.7 meters should immediately remove the sealant membrane and fill with clay. No sealant membrane should be used on the banks.

4.       The installed sealant membrane in Fuhai Lake should be modified. Where gravel has been used as fill, the surface sand should be replaced with natural clay and all the original sediment should be replaced. Other than the area within 10 meters of the dock, the sealant membrane on the revetments of other areas should be removed to ensure adequate infiltration. Additionally, in order to satisfy the ecological needs of the Old Summer Palace park grounds, water usage plans must be made systematically, and the efforts must be made to ensure the quality of the water and prevent contamination

Map of the lakes within the Old Summer Palace and location in China. Source: On sealing a lakebed: mass media and environmental democratisation in China. Ji Ma, 2009

The assessment by Tsinghua University was accepted by SEPA. The report also acknowledged that while these recommendations would likely improve the water shortage situation in the lakes, the impact of the regional hydrology was likely to suffer, and because construction of the sealed lakebeds already neared completion at the time of the report, the true ecological costs of the project could not be assessed.

The expert team from Tsinghua University and general public participants in the hearing mentioned the use of reclaimed wastewater to replenish the lakes. However, like many other water-intensive industries that have been instructed to make use of the city’s reclaimed wastewater resources, it is possible that the limited distribution network and the quality of the reclaimed wastewater may make this difficult presently. In addition, other experts suggested that the sizing and depths of the lakes be adjusted to reflect Beijing’s current water scarcity situation.

Although there may not be one comprehensive answer to the challenges of preserving this historical site, the public hearing held by SEPA at the time fostered the government’s support of public debate on environmental issues. One source reports that in a random sampling of 100 articles returned from a Google search “The Old Summer Palace EIA”, 60 were classified as news articles from major media sources, and 15% were articles from personal blogs or webpages. BBS threads were also an important means of communication, with about half expressing “outrage”, one-sixth supporting the idea of water-tight membranes for conserving water in the lakes, and about 35% expressing neutrality. The second-most supported BBS message on one forum (after one expressing outrage at the membrane itself) was one that expressed dissatisfaction with the fact that the construction of the project was begun without any environmental impact assessment.

A report done by the Woodrow Wilson International Center for Scholars, found that EIAs in China currently do not sufficiently incorporate ecological issues. A personal conversation with a developer based in Beijing, also confirmed that of all the permits required for a new development, the environmental permits are the easiest to secure. The major problems were listed as follows:

Lack of baseline information about ecological subjects;

Inadequate skill sets among environmental assessment practitioners related to impact prediction, mitigation and restoration, and monitoring.

Post-impact monitoring is not strongly emphasized in training programs

Little value of the importance of public participation in assessments and methods to involve communities

Insufficient sharing of best practice models and international experiences among assessment practitioners.

The above are opportunities for improvement, but, the direction is positive. The same report states that a survey of practitioners of EIAs in China revealed that all showed genuine interest in learning how to better predict environmental impacts. In 2002, the Central Government also released a new version of the China Environmental Impact Assessment Law, which, in addition to requiring all renovation and construction projects carry out EIAs, also encourages greater public participation in the “social duty” of environmental protection. The case of the lakebed sealing at the Old Summer Palace Site, is an excellent and positive example of the future of public participation and EIA.

Water Efficiency Series: Part 3- Water Scarcity, Awareness and Rainwater Harvesting

May 9th, 2011 by

When looking at a map it appears that we have more than enough water to sustain all of the earth’s inhabitants with plenty of clean water.  However, less than 1% of this water can meet human’s freshwater needs. (Source: Sherwood Institute Blog “All the Water in the World”, Aug. 25 2010).  At present there are water wars in countries around the globe because of the scarcity of the valuable resource. Meanwhile, in many countries (such as the U.S.) we are over-using water without even thinking about it.

My best friend lives in St. Thomas. When I visited her last year, I was amazed that ALL of the water she used was rainwater from a rooftop catchment system.  I was there for 10 days and in that time quickly adapted to “West Indian Showers” (turning on the water only for a few seconds at and the beginning and end of your showering process), using the absolute minimum amount of water for dishwashing, and learned the phrase “in this land of fun and sun, we don’t flush for number one!”

Picture from sign in bathroom of Soggy Dollar in Jost Van Dyke, BVI Source:

Although the island life takes a little getting used to, when I returned home I was SO conscious of just how much we, as a society, waste water.  My roommate would defrost chicken by running cold water over it- for hours! Despite my complaints and explanations of why it was wasteful, she couldn’t understand that water is a precious resource.

Compared with other developed countries, the United States has some of the lowest water/wastewater costs as a percentage of household income.  I know that when I became responsible for paying gas and electricity bills, our thermostat turned down and I became much more conscious of conserving energy.  As a renter, I have still never had a water bill in my name, as is the same for most young people.  Water seems free, and even for my landlord who is footing the bill; it is a very low cost utility.

At present, the cost of water does not reflect the value of the resource.  Water infrastructure is aging and revenue generated from the sale of water is needed to improve water services.  Increasing the price of water will not only generate revenue to improve the infrastructure but should also help to make the public understand that water is a valuable and precious resource.

In the United States, we are lucky to have infrastructure for delivering water conveniently and cheaply to our faucets. However, it takes a huge amount of energy to transport and treat water.  Rainwater is an under-utilized resource that can be used as potable water without extensive pumping and treatment.

In many areas of the world, rainwater is used for everything: showering, drinking, dishwashing, irrigation and toilet flushing.  However, in developed countries, which do have advanced water infrastructure, rainwater is generally used only for non-potable uses such as irrigation, toilet flushing, laundering, emergency water supplies, fire prevention use and process water uses.

Rainwater harvesting is a very scalable technology that can be as simple as catching rainwater from the roof and delivering it to storage tanks for irrigation or can be as complex as a large cistern with treatment processes for indoor use.  It is important to match the rainwater use to the level of treatment provided.  Water used for irrigation does not need to be treated to potable water standards, as that would be a waste of time, energy and money.  However, if the water will be used indoors, it is important to insure that it is adequately treated to mitigate health concerns.

Simple rainwater catchment system Source:

Complex rainwater harvesting system with ozone and UV treatment Source:

There are so many benefits of rainwater harvesting! These include (but are not limited to): minimizing stress on municipal systems (supports supply and reduces infrastructure maintenance costs); reducing energy required for treatment and pumping of centralized systems (thereby reducing greenhouse gas emissions); providing independent water security especially in times of natural disaster; often providing cost savings over time; decreasing municipal stormwater intake (thus reducing flooding, lessening quantity of stormwater needing treatment, and minimizing sewer overflow); and offering community benefits such as open green areas, public water awareness and self sufficiency.

Although using rainwater can be very beneficial, it is important that the catchment systems are designed well and with caution.  Most concerns are related to health concerns from biological or chemical contamination. However, in good designs most of these worries are minimized.  It is important that municipalities recognize the benefits of rainwater harvesting and create guidance to encourage safe catchment system design. Equally important is for citizens to use these regulations when building a system.   Lastly, it is important that systems are inspected regularly to insure against contamination and to ensure that the water stays at a healthy pH level.

In conclusion, it is important to grow awareness in many developed countries about the scarcity of water.  One way of doing this is by raising water prices to full-cost pricing.  Once people become more conscious that we need to look at other water sources, hopefully rainwater harvesting will become more popular.  Rainwater catchment systems are very scalable and have many benefits, but most be designed cautiously to ensure the rainwater remains safe.  Hopefully, systems will become more prevalent to reduce the impact on current infrastructure and to ensure security to our water systems.

Water Efficiency Series: Part 2- Utilizing Graywater

April 20th, 2011 by

Graywater, or “light graywater” is generally defined as water that has not been in contact with human waste and organics, water that has been used once in sinks, showers or washing machines.  This differs from “dark” graywater, which includes water from kitchen sinks or dishwashers, and blackwater, which is wastewater from toilets.

It is estimated by the US EPA that the average household of four uses about 400 gallons of water per day.  Approximately 70% of this is for indoor use and over 10% is usable graywater. As many states and countries are facing droughts more often, reusing graywater could prove to be a very beneficial strategy.

Graywater is most easily and commonly reused for irrigation purposes. The safest method is subsurface irrigation, where the water does not come in contact with humans and where amounts are generally not significant enough to infiltrate the drinking water supply.  Whitewater (potable water that meets the EPA’s drinking water standards) should still be used for irrigation of food crops other than fruit and nut trees where the crop is far away from the ground.  Subsurface irrigation ensures that the graywater will not pool on the surface or runoff, which could result in odors, mosquitoes, pollution, building damage and unsanitary conditions.

According to the U.S Geological Survey, about 1/3 of residential water use is used outside (mostly for landscape irrigation), which is about 7.8 billion gallons a day! (Source: U.S. EPA’s Water Efficiency Landscaping publication).  This means there is a huge opportunity to recycle water for irrigation purposes.

Graywater systems for reuse generally consist of collection plumbing, treatment methods, disinfection and distribution components.

Dual plumbing is required in order to separate wastewater from graywater and blackwater sources.  If graywater is used for subsurface irrigation, the system can be very simple, with just a three way manual valve installed that can cut off graywater to irrigation if an anticipated load is too heavily contaminated.  Soil must also be tested prior to design to determine if a surge tank is needed to handle peak water loads.  The surge tank is not a long term storage tank. Graywater should be treated or distributed immediately as the organic material in the water will cause it to become unusable and possibly harmful in as little as 24 hours.

For complex systems the next step is treatment.  These scenarios include but are not limited to: graywater used for surface irrigation or indoor use, large collection sources, systems that store water and areas with stricter permitting regulations.

After a filtration pretreatment, treatment methods can include mulch basins, media filtration, filtration membranes, biological treatment and constructed wetlands.  I highly recommend reading Sustainable Infrastructure: The Guide to Green Engineering and Design to learn more about each method as I could write an entire blog about each one!

Water Recycling Treatment and Uses. Source:

After treatment, water should also be disinfected if it will be used indoors or aboveground.  Water can be disinfected using ultraviolet irradiation or by adding chemicals such as chlorine, chlorine dioxide or iodine.  Non-chemical methods are preferable, but also more expensive.

There are many ways to distribute graywater.  In the simplest of systems, gravity carries water from the building to the lower-elevation landscape.  Advanced systems generally require pumping in order to force water through treatment equipment.  Water can be distributed through single or branch pipe systems directly to the landscape, to mulch basins, to small leachfields, through a perforated pipe to gravel filled trenches, to subsurface drip systems, or to subsoil infiltration galleys.

Graywater Reclamation Diagram. Source:

Graywater can be an excellent water resource; however, many factors contribute to ensuring a high-quality system.  First of all, thorough planning and sound engineering are essential for a successful system.  The soil conditions, climate, anticipated loads and end use are just a few of the many issues that must be analyzed during the design process.

After construction, the user must carefully maintain the system and be conscious of what is entering the system.  Before doing research on graywater systems, I was very concerned about how soaps and detergents can be okay for plant life.  I learned that although it is important to use environmentally-friendly products and be aware of what is going down the drain, generally the chemicals and salts introduced to plants and soils in small-scale graywater irrigation projects are usually too minimal to have any negative effects.

In fact, some of the articles I read stated that the nitrogen and phosphorous from soap and the potassium found in food actually nourishes plant life and recharges top soil.  It is most important, however, to avoid soaps with sodium, chlorine, boron, borax, bleach and high levels of phosphates.

Oasis Laundry Detergent, safe for wash water recycling. Source:

As policies allowing and promoting graywater use are beginning to increase, there are more and more government resources to read and learn all about graywater use.   The EPA water recycling and reuse website, the Graywater Guidebook released by the State of California and Sustainable Infrastructure: The Guide to Green Engineering and Design are a few resources to start with.  I hope graywater use will continue to expand and be more widely accepted as a water resource with the general public, as water recycling will help alleviate some of the stress on our current infrastructure. Water scarcity is an growing problem that will only increase in the years to come, we need to start implementing solutions now.

Water Efficiency Series: Part 1- LEED Concepts and Strategies

April 11th, 2011 by

Recently I have been studying for the Leadership in Energy and Environmental Design (LEED) Green Associate exam. The LEED system has become a useful tool in the green building field.

It does not do the work of the design team, but rather sets goals and provides the framework for a green building project.  I believe that it has also helped to advance the use of sustainable practices by providing a recognized benchmark, which has market value.

The LEED Green Building Rating System is a point system based on the following categories: sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environmental quality, innovation in design and regional priority.

There are 100 possible credit points in each of the first 5 categories.  Innovation in design and regional priority credits allow for up to 10 bonus points.  Based on how many points a project obtains, it will receive a certification, silver, gold or platinum status.

LEED Point System. Source:

While studying I was particularly interested in the water efficiency category and decided to get a more detailed understanding of the LEED credits by re-reading the chapters on water conservation and supply and integrated water management in Sustainable Infrastructure: The Guide to Green Engineering and Design.

In this blog I write about the water efficiency credits for LEED certification, and in subsequent posts I will go into further detail about some of the strategies that LEED recommends.

The water efficiency category for LEED certification provides benchmarks to reduce water usage and provides suggestions to accomplish this, such as, using efficient plumbing fixtures, using graywater or captured rainwater for non-potable uses, applying xeriscape landscaping techniques and installing sub-metering devices.

Water Efficiency Points. Downloaded at

The most environmentally and wallet friendly way to protect water resources is to simply reduce demand and conserve water.  LEED addresses this by suggesting low-flow faucets, showerheads, and toilets, dual flush toilets and waterless urinals.  The Bank of America headquarters in New York City, which achieved platinum certification in 2008, estimates saving 3.4 million gallons of water per year by using waterless urinals and 1.1 gallons per year with low-flow bathroom fixtures!

LEED also suggests decreasing water usage by using non-potable water.  Non-potable water is water that does not meet drinking water standards set by the Environmental Protection Agency (EPA), but can be used for purposes that do not come into human contact. Sources of non-potable water include captured rainwater, stormwater, and graywater.   Using non-potable water for irrigation purposes is the safest and easiest use, especially using sub-surface irrigation. However, it can also be used indoors for toilet flushing and process water (cooling towers, boilers, chillers and commercial kitchen use).

In addition to using non-potable water for irrigation applications, we can minimize water usage for landscaping by choosing native plants and applying xeriscaping.  Xeriscaping is a type of landscaping which emphasizes minimal water use, soil improvements, mulching and efficient irrigation.  Designers should also use efficient irrigation equipment; for example: sprinkler systems are only 65% efficient while drip systems are 90% efficient.

Xeriscaping Landscape Design: Source:

Lastly, LEED suggests installing sub-metering devices for indoor, outdoor and process uses.  Sub-metering is useful for monitoring water use, identifying leaks or problems, and tracking peak periods of water use.  Most sub-metering devices track cold, potable water use.

Strategies such as “use low-flow plumbing fixtures” or  “install sub-metering” are relatively self-explanatory and do not require much design engineering.  However, utilizing graywater, harvesting rainwater and treating wastewater can be much more intensive strategies.   To understand these techniques, I turned to Sustainable Infrastructure: The Guide to Green Engineering and Design. In upcoming posts I will describe these methods in more detail.

World Water Day 2011

March 21st, 2011 by

The United Nations General Assembly declared the first World Water Day as March 22, 1993.  Eighteen years later March 22 still serves as a day to focus the world’s attention on the under availability of freshwater and the importance of sustainable water management.

Each year a new topic is presented for the world to spotlight.  In the past these topics have included women and water in 1995, groundwater in 1998, water and disasters in 2004, water and culture in 2006, water scarcity in 2007, and water quality in 2010.  This year the theme is “Water for Cities, Responding to the Urban Challenge.”

Currently, 3.3 billion people live in cities.  That number grows by two people every second.  This accounts for half of the world’s population.  93% of this urbanization occurs in poor, developing countries.  People in underdeveloped urban areas have the least access to freshwater and also pay the highest costs for “clean” water.

Photo of home from WWD Flickr page. Source:

Utility companies in urban areas are becoming less able to sustain themselves.  It is becoming impossible to extend sewers to slums and current piping infrastructure is already unable to handle waste loads in many areas.

It is for this reason that all infrastructure projects must begin using sustainable designs, especially water and wastewater projects.  These measures should include rainwater harvesting, low impact development stormwater design, sustainable blackwater management, and water recycling, reuse, and conservation.

There are five key messages that need promotion regarding urbanization and water services.

  • The impact of urbanization on the water sector: as the world’s population grows, especially in informal cities, providing water and wastewater services will become increasingly important.
  • The impact of sanitation, pollution and industrialization on the environment needs to be recognized.  Two of the UN Millennium Development Goals are “halve, by 2015, the proportion of the population without sustainable access to safe drinking water and basic sanitation” and “by 2020, to have achieved a significant improvement in the lives of at least 100 million slum dwellers.”  Utilities and local governments need to push to meet these goals and explore opportunities to reuse urban waste in a way that can have social, economic and environmental benefits.
  • World Water Day 2011 is focusing on the importance of non-corrupt, committed government and utility management.  Strengthening local governments and improving regulation, professionalism and accountability to customers is vital in advancing water and wastewater services, especially in underdeveloped countries.
  • Many counties can simply not afford to keep up with the implementation of new and sustainable infrastructure.   New investment opportunities need to be explored, including tariffs, taxes and transfers.
  • It needs to be understood that water availability depends on natural resources and in the future these resources are threatened by extreme weather events and a changing climate.   It is becoming increasingly important to adapt infrastructure to climate change, to protect the environment when designing new networks and to reuse water to improve quality and quantity.

Flood survivors outside Peshawar, Pakistan. Follow source link to read story behind photo. Source:

The growing population in cities creates huge opportunities!  Cities are the hub of employment and wealth, as well as creative thinking.  This means that hope for development of water and sewage services are greater in urban areas than rural areas which are more spread out and generate less income.

Hopefully, World Water Day 2011 will serve to expand the knowledge about the growing problem of water and urbanization, facilitate policy dialogue and promote discussion about innovative solutions to water and wastewater management issues.

The main event for World Water Day 2011 is being held in Cape Town, South Africa.  However, there are SO many events being hosted all around the world.  The official World Water Day website has a map and events lists to find and join in on events in your area.

The World Water Day 2011 official website has a huge amount of information on the event and links to materials and reading about water and urbanization.  I encourage everyone to take a look and explore online a bit.

Waiting for water in Bangladesh, Source:

Renewable Energy: Water Power; Part 3 of 3

March 14th, 2011 by

This is the final segment on five types of hydrokinetic technologies, all mentioned in Sustainable Infrastructure: The Guide to Green Engineering and Design by S. Bry Sarté.  These systems are microhydroelectric, wave energy, vortex-induced vibration (VIV), tidal power and ocean thermal energy conversion (OTEC).  My final blog on the topic will discuss OTEC power: how it works, different types of systems, and its many different applications.

Ocean Thermal Energy Conversion (OTEC):

OTEC uses the differences in temperature between cold, deep ocean water and warm, shallow water to power a heat engine capable of producing electricity.  OTEC is most efficient when there is a large temperature difference (approximately 36 degrees Fahrenheit), thus the best potential sites are tropical areas.  OTEC systems are closed-cycle, open-cycle or a hybrid of the two.

Closed-cycle systems pump warm ocean water through a heat exchanger where it is used to heat a working fluid with a low boiling point (such as ammonia).  The working fluid is vaporized and the expanding vapor turns a turbo-generator.  Cold seawater is then pumped through a second heat exchanged to condense the vapor back into a liquid.

Diagram of Closed Cycle OTEC, Source:

Open-cycle systems use the warm seawater directly instead of a secondary fluid.  A low-pressure container causes the water to boil, and like in the closed system, the expanding vapor drives a turbine which, in turn, powers an electrical generator.  This is also a desalination process, as the steam is fresh water.  The steam is condensed back to liquid form by exposure to the cold ocean water.

Diagram of Open Cycle OTEC, Source:

Hybrid systems evaporate warm seawater in a vacuum, similar to in the open-cycle systems.  However, this steam vaporizes a working fluid, similar to a closed system.  Again, the expanding vapor fuels a turbine to produce electricity and the cold ocean water is used to condense the vapor back into a liquid.

Sites can be located on or near land, on continental shelves or as floating facilities.  Each has its advantages and disadvantages mainly related to the difficulty and cost of installation and maintenance and the safety of the facility in turbulent conditions.

OTEC is primarily thought of as a source of renewable energy; however, it has several useful byproducts and uses.

OTEC Applications, Source:

First, as mentioned above, desalinated water is produced in open or hybrid cycles.  A 2MW plant could be capable of producing approximately 150,000 cubic feet of desalinated water per day!

Secondly, the cold seawater needed for an OTEC system can also be used in chilled water coils to provide air conditioning.  The InterContinental Bora Bora Resort and Thalasso Spa is the first hotel in the world to use seawater air conditioning for all of it’s cooling needs.

Deep ocean water is some of the most nutrient rich water in the world.  For this reason OTEC systems support mariculture, which is the farming of aquatic organisms.  Salmon, lobster, trout, oysters, clams, and spirulina are just some of the species that can be raised in pools supplied by OTEC pumped water.

The cold ocean water can also be used in land-based agriculture, by running the water through underground pipes and chilling the soil.  This allows plants to be grown in non-native climates.

OTEC is a promising technology; however, there are still economic, political and environmental concerns.  Hopefully, careful site selection can minimize negative impacts.

All of the water sources of renewable energy are capable of producing huge amounts of energy.  Hopefully in the near future, these technologies will be further optimized so that they can be implemented in more locations with lower costs and environmental impacts than fossil fuel electricity generation.  Water power might well become the “wave of the future”  for renewable energy.

Renewable Energy: Water Power; Part 2 of 3

March 10th, 2011 by

This post is the continuation of my previous blog on water power.  In that segment I summarized tidal and wave energy technology.  I had planned on discussing microhydroelectric installations, Vortex Hydro Energy, and ocean thermal energy conversion (OTEC) in this section, however because there is SO much important information I have decided to again separate the post into another part.  This piece will focus on microhydroelectric power and the Vortex Induced Vibrations Aquatic Clean Energy (VIVACE) system which both utilize flowing water to generate electricity.

Microhydroelectric Installations:

Microhydroelectric power is very similar to hydroelectric power but it is adaptable for small-scale installations such as single homes or small communities.  Microhydro generally only produces up to 100kW of power and is much more sustainable than big, traditional hydroelectric power installations.  And even more appealing is the fact that microhydro does not require rivers to be completely dammed.  This is very beneficial because dams interrupt the water cycle, travel of fish and animals, and the flow of nutrient rich sediment downstream.

Microhydroelectric power is generated using the energy from flowing water.  First an intake tank filters the water to ensure no debris or fish enter the system.  The water then flows through a pipe (called the penstock) to a controlling valve that regulates the flow and speed of a turbine.  The turbine turns a shaft that is used to power a generator, which converts the flow and pressure of the water to electricity!

This energy can then be stored in batteries and distributed to the power system.  At the end of the process, the water used in the system is returned to the river or stream along a tailrace channel.

The image below is from a PowerPoint presentation used in a course I took at the University of Vermont called “Sustainable Development of Small Island States: St. Lucia.”  I had the opportunity to see first hand how well the microhydro system worked for the owner of the land, Mr. Sly Joseph.  Mr. Joseph powered his whole home and an outdoor classroom using the power generated at the La Tille Waterfall on his property.  The local schools teach classes on his property to spread the message about how well microhydro power works, especially on small islands where traditional electricity is very expensive and not readily available.

Diagram of Microhydroelectric Installation, Source:

Vortex-Induced-Vibration (VIV)/ Vortex Hydro Energy:

VIVACE (Vortex Induced Vibrations Aquatic Clean Energy) is an emerging technology that extracts energy from flowing water currents and utilizes the science of vortex-induced vibrations.  Most of the research I could find on the technology was quite confusing, primarily because the science explaining VIV is quite complex. However, using VIVACE technology is actually quite simple. is a great site that explains the system very well.

VIVACE is the only water power technology that I will discuss that does not use any turbines, and because the cylinder oscillations are only about one cycle/second there is not direct threat to aquatic life passing through.

Boxes with cylinders are installed on a riverbed or suspended under the surface of the water, as the water flows through the cylinders the movement causes the cylinders to move up and down. The cylinder is attached to a magnet that also slides vertically, creating a DC current.  The DC current is then converted to AC current.

How the VIVACE system works, Source:

The phenomenon behind how the cylinders of the VIVACE system move perpendicular to the current direction is the same as how fish move through the water.  Very basically, vortices are produced and discarded on the downstream side of round objects in a fluid current.  The vortex shedding oscillates between the bottom and top of the object, thus creating an alternating lift on the body.

VIV Technology, Source:

VIV in the environment (with fish!), Source:

The company responsible for the design, Vortex Hydro Energy LLC, predicts that an array of cylinders about 2 stories high could power about 100,000 homes.  The technology can be used to power desalination plants, use energy from rivers without dams and provide power in coastal areas.

I love the microhydroelectric and VIVACE technologies.  Both are very simple systems that have small-scale potential (unlike wave, tidal and OTEC power which can only be installed for large-scale energy production).   Both systems can be installed on a small river and, without changing the site very much, can utilize the energy in flowing water to provide electricity for a home nearby or a community.   Hopefully these systems will be implemented more to reduce our dependence on fossil fuels and on traditional hydroelectric power which dramatically alters the environment.

Beijing Golf Course Water Conservation Needs and Strategies

February 28th, 2011 by

Since the opening of China’s first golf course in Guangdong Province in 1984, the country has seen a boom in the sport, which is a symbol to many Chinese of luxury, upper class lifestyle, and one of the pinnacles of western recreational status. In China, golf is something that only the very wealthy can afford, with club fees ranging from “cheap” at a couple thousand dollars per year to tens of thousands of dollars per year for the very exclusive courses, meaning that only approximately one in every 100,000 Chinese people could ever afford to play 18 holes in China. Despite the small number of potential Chinese golfers however, the symbol and status of golf in China has created a reasonable market for the development of golf courses.

Such development comes with significant environmental challenges. Most golf courses are constructed in the suburban areas of large metropolitan cities, which, especially in northern China are already strained for water resources. Golf course construction has several implications. Because the water required to maintain greens, tee boxes and fairways is significantly more than that of land covered by trees and bushes, strains are created on both groundwater and municipal water supply. The deforestation of areas to build 18-hole courses also increases soil evaporation, decreases infiltration, increases stormwater runoff and decreases the water-holding capacity of the soil. Also, since many suburban golf-courses are located on lands once used for agriculture, it is common practice to directly extract groundwater from agricultural wells already built on the land for irrigation purposes, which leads to the lowering of the groundwater table in areas which are already experiencing subsidence on a regional scale.

An aerial photo of the Beijing Central Business District International Golf Course. Image Source:

The municipal government of Beijing has of course, realized that this problem could be very severe. This year, in fact, Beijing experienced its driest winter to date, with 108 days straight with no precipitation. There have been several policies passed attempting to curtail water-intensive industries. In 2005, the Beijing Water Authority passed its first announcement on golf course water management, called the “Announcement on the strengthening of golf course water use management”. Within this document, it was specified that the 40 golf courses within Beijing’s 11 districts would have to pay doubled or tripled prices for water usage exceeded a set maximum. The announcement also stated that golf courses were required to utilized reclaimed wastewater for both waterscaping and irrigational purposes and that they should also maximize harvest of rainwater.

In 2006, another announcement was sent to all registered in Beijing, requiring golf courses to register usage of on-site wells, increase permeable areas (such as paths, parking lots, etc) on the site, maintain irrigation equipment, and for golf courses within the distribution network of reclaimed wastewater to utilize this as a source for irrigation, and flushing toilets.

In 2010, the opening of new water-consuming enterprises—including new ski slopes, golf courses, and bathhouses—in Beijing was banned.

While these policies were definitely a step in the right direction, several articles question their efficacy and the extent to which the policies are actually enforced. In March 2010, Probe International published a report which stated that “fewer than 7 percent of Beijing’s golf courses use reclaimed water for irrigation despite municipal guidelines that strongly suggest they do”. On February 11 of this year, the Economist published an article stating that according to aerial photographs, there are 170 confirmed golfing establishments in Beijing, including driving ranges. Previous estimates of the number of golf courses vary because some places avoid calling themselves “golf courses” in order to have more leniencies in management. The official Xinhua News Agency reports 38 golf courses as of 2010

Although there are definitely some questionable aspects of the efficacy of legislation and the commitment various players have in their implementation, there is no doubt that golf courses in Beijing must adopt water reuse and saving measures. There are three main strategies that are important in golf course water management.

The first is to increase the amount of reclaimed wastewater that is being used for irrigation and waterscaping. As of August 2010, only 4 of the 38 official golf courses were utilizing reclaimed wastewater for irrigation. Interestingly, in the same month, it was also reported in Chinese media that the demand for reclaimed wastewater in Beijing far exceeded its supply. In many developed countries, technology is good enough that up to 70% of all wastewater can be reused as reclaimed wastewater after treatment. In Beijing, only about 10% of wastewater is being reutilized, so the potential for reclaimed wastewater to be a major water resource in the future is very large. Because in some cases, wastewater treatment plant effluent may not meet standards for irrigation or waterscaping uses (especially if nutrient levels are high), golf courses may consider the use of constructed wetlands to raise the quality of the water. This strategy may even allow for golf courses outside the reach of the current reclaimed wastewater distribution network to carry out additional treatment of treatment plant effluent to raise the quality of the water independently.

The second strategy that will be important for golf courses in Beijing to adopt is drainage and rainwater harvest design. Because grass lawns experience greater runoff than forested areas, specific attention needs to be considered in the grading of the landscape with respect to maximizing infiltration into the underlying aquifers and in minimizing waste during irrigation. Expert engineers should be consulted for questions relating to soil type, infiltration speed, soil water capacity, and grading.

Lastly, the selection of drought-resistant plant species should also be considered in golf course design. Already in Beijing it is reported that drought resistant grass is already being used for fairways and roughs, which typically account for over 60% of the total area of the course.

Research is being done on golf industry development at the Turfgrass Institute of Beijing Forestry University.

Renewable Energy: Water Power; Part 1 of 2

February 25th, 2011 by

The ocean has always intrigued me.  Growing up I got hooked on sailing and fell in love with its beauty. I also developed a healthy respect for its power. I clearly remember a high school presentation about wave and tidal power.  I was so intrigued about how energy could be harnessed from water and used as a source for renewable energy.

Sustainable Infrastructure: The Guide to Green Engineering and Design by S. Bry Sarté mentions five types of hydrokinetic technologies: microhydroelectric, wave energy, vortex-induced vibration (VIV), tidal power and ocean thermal energy conversion (OTEC).  The Sherwood Institute focuses on the water-energy nexus, and although much of its work focuses on the balance of water and energy efficiency, I thought energy generation using water an appropriate topic to discuss.

In this first blog, I will summarize research on wave energy and tidal power.  In part two, I will discuss other popular types of water power.

Wave Energy:

Energy from the ocean can be generated using a variety of technologies that capture energy from surface waves or pressure fluctuations below the surface.  The devices are all installed at or near the water’s surface; however, they can be located nearshore, offshore or far offshore.

There are many devices being developed to harness this power. I’ve focused on four primary technologies: point absorbers, overtopping devices, attenuators and terminator devices.

  • Point absorbers use the relative motion created by waves of a floating buoy to a fixed structure to power electromechanical or hydraulic energy converters.
  • Overtopping devices consist of a reservoir and turbine system.  Incoming waves fill the reservoir, making the water height in the reservoir higher than that of the surrounding ocean.  When the water is released, the energy of the falling water drives a turbine or other conversion device to create electricity.
  • Attenuators are floating structures that are situated in the same direction as wave travel.  The multi-segment device flexes as waves pass. This flexing drives hydraulic pumps and converters.
  • Terminator devices are generally designed to be near shore.  They are oriented perpendicular to the wave direction.  One form of terminator device is the oscillating water column, which allows water to enter the bottom of a column filled with air.  Passing waves cause the water column to move up and down. The forced-out air powers a turbine to convert the energy to electricity.

Image of Wave Energy Technologies, Image from

The prospect of harnessing wave energy is very promising.  However, there are environmental considerations: visual appearance and operation noise above and below the surface, marine habitat changes, accidental release of hydraulic fluids, sharing sea space with recreational and commercial boaters, and possible reduction in wave height and site change while installing or decommissioning devices.  Many of these concerns can be addressed with careful site selection and monitoring; however, they are matters that must be addressed.

If you are interested in learning more about wave energy research, I suggest reading Technology White Paper on Wave Energy Potential on the U.S Outer Continental Shelf.

Ocean Tidal Power:

Tidal power harnesses energy from the changing tide.  In some areas, the gravitational pull of the sun and moon and the rotation of earth can cause up to a 40-foot water height differential between high and low tide.  Most of the technology for harnessing tidal power uses submerged turbines similar to wind turbines.  There are three well developed methods for capturing this energy: barrages, fences and turbines.

  • Tidal barrages are dams across an inlet with gates that allow water to flow into the area and then empty during the ebb tide.  As the water flows in and out of this “tank”, the water flows through turbines which activate electric generators.

Image of gates and turbines from a tidal barrage, image from

  • Tidal fences are generally used in channels between two landmasses.  Vertical axis turbines are mounted on a fence.  As water flows past these turbines, the current causes the turbines to spin.  The turbine action, again, drives electric generators to produce electricity.

Image of tidal fences, image from

  • Tidal turbines can be located anywhere where there is a strong tide.  The turbines are arrayed in rows, similar to wind turbines on a wind farm, only underwater.  The current of the ebbing and flowing tide cause the turbines to turn and produce electricity in the same fashion as the two previous technologies.

Image of tidal turbine, image from

Water is about 800 times denser than air.  Therefore, turbines located underwater have enormous energy potential.  However, there are a lot of environmental concerns, including: sea-life migration, navigational and recreational disadvantages, and changing the ecosystem in barraged areas where silt buildup can occur.   Tidal turbines might prove to have the least environmental impact because they do not block the natural flow of water like the other two methods.

I believe wave and tidal energy hold enormous potential!  The ocean is so powerful, and both forms of renewable energy generation could produce an incredible amount of electricity.  However, there are cost and environmental concerns that still need to be addressed – and utilizing these technologies are only possible on a large scale and in very specific site locations.  These forms of power are still being intensely researched, so, hopefully, new technologies will minimize environmental impact and maximize the amount of electricity that can be generated so that more sites can be used to produce these types of power.

In my next post, I will continue the water power discussion by addressing micro-hydroelectric, ocean thermal energy conversion and vortex-induced vibration power.

Sustainable Solutions for Hot Water Production and Water Conservation

February 22nd, 2011 by

As I have previously mentioned, I live in Lake Tahoe, CA.  Although it has been abnormally warm this year (60 degree spring-skiing days in January!), the water in our house runs SO cold for SO long!  Since we keep the house at a pretty chilly temperature, this icy water makes for a very unpleasant hand washing experience.

Despite doing things like brushing my teeth and letting the water drip for the cat (my crazy Bengal refuses to drink anything but water from my own drinking glass or a running faucet!)  BEFORE washing my hands, the water still needs to run for far too long to get warm. Or I have to suffer and have freezing cold hands!  I have also heard many people complain about how cold the water is in the public bathrooms at the ski resort.

People in cold ski towns don’t like cold water.  So, I decided to learn more about sustainable ways to heat water and reduce the use of un-used, cold water.

Sasha drinking water from the faucet

A few facts about unused water waste:

-Running the water for a few minutes, even with low-flow fixtures, wastes approximately 3-5 gallons of water.  For a family of four, that is about 15,000 gallons of water a year.

-If someone drinks the recommended 8 cups of water a day, that is only 185 gallons of water needed per year.  Meaning, just by running water, waiting for hot water, you could be wasting about 20 times the amount of water you drink per year.

-Running hot water is a huge energy drain! Running your faucet with hot water for 5 minutes is equal to the energy usage of a 60-watt light bulb for 14 hours!

The good news is, there are many ways to maximize water and energy efficiency for hot water.  These include using low-flow water fixtures, insulating hot water tanks and piping, planning hot-water tank placement to minimize piping, using EnergyStar and WaterSense rated appliances, and being conscious of water usage when taking showers, brushing teeth, washing dishes and laundry, etc.

In addition to all of these improvements, there are a lot of choices to make when deciding what the best type of hot water heater to use (tankless, on-demand, re-circulating systems, solar-hot water… the list goes on).  For this blog I am going to focus on residential hot water, highlighting one system for energy efficiency and another system for water efficiency.

One of the most sustainable methods for heating water is solar thermal (heating water using solar radiation). This is discussed in Sustainable Infrastructure: a Guide to Green Engineering by S. Bry Sarté. This heated water can be used for residential hot water, hydronic radiant floor-heating systems, heating swimming pools, and even commercial electricity generation.  A typical solar hot water system can provide enough hot water for the average home.

Solar thermal collectors are generally black coils filled with water, which are installed on the roof.  The water heats up in the sun and then is stored in a tank until needed.  Systems are almost always constructed with an auxiliary water heating system that is activated if the water drops below a set temperature so that hot water is always available.  Solar thermal hot water generation is a relatively cheap system, much less expensive then solar photovoltaic panels used for residential electricity generation, so they can be a nice place to start when greening your home.

Solar Thermal Hot Water System Diagram, image from:

Solar thermal systems can be passive or active.  Passive systems use convection to naturally move the warmer liquid (water or a antifreeze heat transfer fluid) to the storage tank and cold water to the collectors for heating.  These systems are simpler and less costly than active systems but can only be used in moderate, sunny climates.

Active systems use pumps to move water from the collectors to storage tanks.  This allows the tank to be situated under the collectors, which can increase efficiency since it can be stored indoors in a more insolated space.  A controller is also used to ensure that water is only being pumped when the water in the collector is warmer than in the tank.  In addition to increased efficiency, active systems have less risk of overheating and freezing because of the tank location and the use of a controller.

Active and Passive Solar Hot Water System Diagram, image from:

Because I am concerned with just how much water I have been wasting while waiting for hot water, the water efficiency technology I was most intrigued by is the hot water demand/cold water return system. This system works by returning cold water to the heat source, instead of letting it drain, becoming waste water.  I found that the Chilipepper pump website had some of the best explanations on how the method works, so I encourage you to learn more by checking it out.

Basically, when you go to the sink you turn on a pump that begins drawing hot water from your water heater (these work with any type of heating/storage system).   Water going through the pump is returned to the water heater until the pump sensor detects water temperatures above a set temperature.  At this point the pump will turn off and allow the hot water to flow to the faucet.

These pumps also draw water faster than most fixtures, especially new low-flow faucets and showerheads. This means that the outlet will receive hot water much more quickly than without the pump. Also, since the water isn’t being wasted while waiting for it to heat up, you don’t need to be concerned about the high flow rates.

Cold Water Return System Diagram, Image from:

There are so many other ways to save water and improve energy efficiency with hot water. This blog would be way too long if I explained them all!  I encourage everyone to research the topic more.  Point of use water heaters or a tankless heater might be a good way to green your hot water heating system.  The EPA also has a great program called WaterSense, and I encourage you to look at their website; it is filled with suggestions on how to reduce water-waste.  Limiting hot water use, using sustainable methods to heat water and not wasting unused water all help to make a home environmentally friendly. I hope the methods mentioned above are helpful and jump-start your thinking about hot water usage!

Book Review and Highlights: Cradle to Cradle -William McDonough & Michael Braungart

January 18th, 2011 by

My current focus is to learn as much as possible about sustainable design, share my explorations with Sherwood Institute Blog readers, and hopefully inspire those following my blog to travel down a similar path of learning and implementing green strategies in their work.

I heard William McDonough speak at West Coast Green 2010. His speech was one of the most inspiring of the conference and I knew that I wanted to read more about his and co-author Michael Braungart’s philosophies on design.  I wasn’t disappointed! Cradle to Cradle by William McDonough & Michael Braungart should be required reading for anyone involved in design, if not for the general public.

This book on “re-making the way we make things” is a motivating reference that focuses on the necessity of designers to change their common approach to product development.   It is possible  – and even essential – that we begin creating products that are good for the environment, not just “less bad.”

For example, instead of just aspiring to create a car that has zero emissions, car makers could begin designing “nutri-vehicles” which would release emissions that are actually good for the environment and its inhabitants.  The average car releases about four-fifths of a gallon of water vapor for every gallon of fuel the car burns. What if that water was captured and re-used?

I want to focus this post on my three favorite concepts from Cradle to Cradle: that we can create a world of abundance, that waste equals food, and that products of service can be a useful way to make goods which are more eco-conscious.

First of all, a world of abundance refers to a planet filled with products that celebrate culture, improve the economy, and have ecological benefits. How wonderful would it be if environmentalists and industrialists could both encourage vehicle production, because old cars could be 100% recycled, and new “nutri-vehicles” would not only not pollute, but would also purify the air and provide drinking water.

As someone who loves nature and wants to protect it, I really like the idea that I don’t necessarily need to make sacrifices such as driving less, buying less, and not having children.  We need to foster a society where all professionals have the same aspirations so that skills can come together to create a world of economic prosperity while safeguarding our culture and resources for future generations.

Waste equals food refers to the re-using of materials so that all waste is used to make an improved product or is returned to earth where it can benefit natural systems.  “To eliminate the concept of waste means to design things – products, packaging, and systems – from the very beginning on the understanding that waste does not exist.”  (Page 104). McDonough and Braungart suggest that this can be accomplished by dividing materials into two categories, biological nutrients and technical nutrients.  Biological nutrients are all products that can safely biodegrade and even improve soil as it decomposes.  Technical nutrients are all materials from old products that can be unassembled and reused as raw materials for improved goods.   It is important that biological and technical nutrients be kept separate so that the entire product can be disposed of to enrich the planet, or returned to manufacturers who can “up-cycle” the product into a new product of the same nature.

The authors of Cradle to Cradle actually created a prototype of a technical nutrient in the printing of their book. It is printed on synthetic paper made of plastic resins and inorganic fillers with water-based ink.  Not only were no trees harmed for the printing of this book, but the after products can also be recycled over and over again as “paper” for new books.  Although paper made from trees is recyclable, it needs to undergo extensive chemical processes to make it ready for re-use; these often toxic procedures also produce a product which is not as high quality as the original.

In order for products to stay in their respective biological or technical cycles, the authors introduced the concept of products of service.  I love this idea!  Instead of companies selling products that are bought, used, and then disposed of, what if manufactures instead sold them as services?

For example, a washing machine could be bought for 2,000 wash-cycles, then returned to the manufacturer who would be happy to take it back to acquire the raw materials for newly-designed machines. The consumer would be excited to receive the latest machine and begin a new “lease.”  This idea can be taken even further to include soap with the washing machine service.  McDonough and Braungart inform us that only about 5% of soap used for washing clothes is actually used in the wash cycle.  What if the soap could be re-used internally? Manufacturing, packaging and shipping new detergent would no longer be necessary.  By developing products of service, technical nutrients could remain in the technical cycle instead of “dying” in a landfill. Designers would develop products that could be easily disassembled and re-used.

I would highly recommend Cradle to Cradle to anyone interested in sustainability.  It’s an easy read that starts to get the mind’s gears turning and thinking about designing products that are truly positive for our planet and our own health.  How cool would it be that if instead of leaving a detrimental ecological footprint, we instead left a footprint that actually helped our environment? It is indeed possible so let’s begin doing it!

Smart Growth and Ahwahnee Principles

January 7th, 2011 by

In May of 2009 I attended the Bertram Berger seminar in Boston regarding Climate Change.  One of the most memorable speakers was Elisabeth Hamin who spoke about smart growth and livable communities.    I loved the philosophy that new developments should be planned so that dependence on automobiles is reduced, community awareness increased, and natural, open areas introduced to urban neighborhoods.

Example Smart Growth Diagram. Source:

While reading about Ahwahnee Principles in “Sustainable Infrastructure: The Guide to Green Engineering” I was reminded of the smart growth initiatives that previously intrigued me.  I decided to do research about the polices and share my findings.

The Ahwahnee Principles were initiated by Peter Katz of the Local Government Commission (LGC) and developed by innovative architects: Andres Duany, Elizabeth Plater-Zyberk, Stefanos Polyzoides, Elizabeth Moule, Peter Calthorpe, and Michael Corbett.  In 1991 the principless were presented to over 100 local officials at the Ahwahnee Hotel in Yosemite, California, where they were eagerly accepted.

The first set of principles was titled “Ahwahnee Principles for Resource Efficient Communities.”  This plan includes community, regional and implantation polices.  The community principles emphasize developing neighborhoods so that homes are located within walking distance of retail shops, schools, and public transit.  There are also concepts that encourage people of all age groups and incomes to live near one another, and that highlight the importance of open space and greenbelts defining each neighborhood.  Lastly, the principles state that development should be designed to use resources such as water and energy efficiently.

Green Area Surrounding Development. Source:

In 1997, the LGC realized the need for a similar set of policies regarding the economic development of livable communities.  This was titled “The Ahwahnee Principles for Smart Economic Development.”  This document consists of 15 principles to guide economic policies that emphasize the importance of local enterprise and using regional resources.

Local Market. Source:

The “Ahwahnee Water Principles” were adopted in 2005 as a second compliment to the “Ahwahnee Principles for Resource Efficient Communities.”  These principles developed out of increasing challenges related to water resource security, water contamination, storm-water runoff, and increased flooding.  The water principles include, but are not limited to: designing compact communities, maintaining natural areas, minimizing impervious surfaces, reducing water demand for landscaping, graywater re-use, installation of water-efficient appliances, public input regarding projects and monitoring of new developments and policies.

Green Stream, Source:

Lastly, the LGC developed the “Ahwahnee Principles for Climate Change.”  These principles prescribe methods to actively mitigate damage that society is doing to the planet, and adapt our current infrastructure systems to inevitable changes in our climate.  These principles include: reducing emissions from automobiles, energy and water efficiency for the residential and commercial sectors, and implementation strategies to achieve these desired reductions.

Like most sustainable/green concepts: the Ahwahnee Principles just seem to make sense.  I didn’t think about it when I was younger, but as I matured I began to really appreciate growing up in a historic town, Marblehead, MA, first developed in the 1600s.  In Marblehead, there are two downtown areas, several small elementary and middle schools, and many parks so I didn’t need to depend on my mom to drive me around as a kid.  I could walk to school, after which my friends and I could bike to a park, play some games outside, get dinner at a pizza place, grab a movie at the local shop, and bike to someone’s house to watch it.  Because my town was formed in a period when people did not depend on automobiles, it promoted walking and biking.  The Ahwahnee principles define several concepts that bring us back to this traditional style of development and design.

Traditional Walkable Community, Source:

I encourage everyone to spend some time on the Local Government Commission’s website.  The Ahwahnee Principles for Resource-Efficient Communities, Smart Economic Development, Water, and Climate Change are all defined on this website.  Here you can find much more detail on each of the principles sets defined above, as well as case-studies, implementation guides and tools, and many more resources on smart growth.

Strategies for Sustainable Snow Management

December 15th, 2010 by

I currently live  by Lake Tahoe in Placer County, California. We have the highest annual snowfall of any county in the lower 48 US states.  After living here this month, I don’t doubt it!  According to one of the local ski resorts, Alpine Meadows, the snowstorms of November 2010 have produced record amounts of snow, 6 feet in 6 days!

Snow over my head from the storms!

Over the course of the storm I watched as enormous plows cleared the roads. Later huge snow-blowing vehicles would come widen the road. And lastly, after the storm, bulldozers cleared the built up banks and drifts to get the roads, almost, back to normal.

I started thinking about how unsustainable this method of snow removal is.  Not only are there emissions associated with the operation of massive equipment, but also contamination of the snow from salt and sand, road-side litter, and automotive pollutants.  Lastly, snow removal is hugely expensive! In Placer County 15-20% of the annual road maintenance budget is spent on snow and ice control.  I decided to do some research into solutions that incorporate sustainable snow removal and possible reuse in areas that receive a large amount of snow precipitation.

The most inspirational methods came from the City of Sapporo, the capital of the northern-most Japanese island of Hokkaido.  Sustainable urban development is at the core of Sapporo’s city planning, and as a city with approximately 20 feet of snow accumulation and a population of 1.9 million people, it is vital that snow removal be part of the city’s sustainable initiatives.

Sapporo minimizes its dependence on snow-related transportation using heated roadways, centralized and local snow disposal facilities, and snow melting systems.  In addition to a large, underground snow-melting tank, Sapporo has five Snow Flowing Gutters, which use river water and reclaimed water to move and melt snow.

This gutter system particularly intrigued me.  Basically, there are grates at the sidewalk’s edge.  Citizens then dispose of the snow in front of their residence and businesses into the gutters.  The flowing water carries the snow to a treatment plant or to a snow-melting tank.  If reclaimed wastewater is used, the temperature of the flowing water is generally about 50 degrees Fahrenheit, which melts the snow.  This system eliminates the use of large mechanical vehicles and the emissions and cost associated with them, reduces the need to chemically melt snow, and empowers the city’s inhabitants to help with snow removal.  However, the system is still centralized and the reclaimed water and melted snow are still being carried through pipes off-site.

Diagram of Snow Flowing Gutters: Photo from page 104 at,S-IDcdrom-e.pdf

Photos from inside the snow-melting tanks/gutters:Photo courtesy of the City of Sapporo, Japan in the publication: Asano, Takashi. (2007) “Water Reuse: Issues, Technologies and Applications,” Metcalf & Eddy, Inc.

I wonder how this system could be further developed. Instead of just transporting and disposing of the snow in an innovative way, what if the water from the melted snow could be reused or treated entirely on site in order to reduce stormwater runoff and recharge the groundwater?  Designers could use low-impact design stormwater or rainwater harvesting principles to the melted snow.

This way snow removal would become part of a circular water system.  In areas with considerable snow accumulation, geothermal heat pumps or energy from renewable sources such as photovoltaic panels or a small-scale wind turbine could heat sidewalks or roadways.  In areas with only moderate snowfall this step could be eliminated.  Remaining snow would be shoveled into grates, bringing it underground where it could mix with reclaimed “waste” water to aid in melting the snow.  Finally, all of the water from the premises (wastewater, graywater, stormwater AND snow-melt) could be handled using any variety of sustainable design strategies.   In this context, I particularly like a system similar to that designed by Sherwood Engineers and CMG Landscape Architecture for Old Mint Plaza, where the combined water could infiltrate to the groundwater table.

On-site drainage system at Old Mint Plaza. Image from

Over the last two weeks of researching the concept of sustainable snow removal, I have come across many concepts that are in use, and I’ve started to think of new ways to manipulate these systems.  I am truly excited about the idea and I would love to hear about any methods that readers have heard of or thought about!

Transition from Traditional to Sustainable Engineering Series

November 30th, 2010 by

Hello Readers,

Welcome to my series on transitioning from a traditional to sustainable engineering practice.  I am currently spending much of my time learning as much as possible about sustainable engineering because I feel that it is imperative that today’s engineers begin to incorporate sustainable strategies in all design work.  I hope that through the Sherwood Institute blog forum I will be able to learn and share new information about greener engineering practices.  I plan to write a bi-weekly blog where I can discuss what I learn and hopefully inspire others to increase the use of sustainable design strategies.

I would like to begin by telling readers a bit about my background and how I became so passionate about learning sustainable engineering methods. I received my B.S in Civil & Environmental Engineering from The University of Vermont, where I was taught by very environmentally friendly professors and surrounded by forward-thinking peers.  It was there that I became interested in the environment and how important it is that we practice sustainable design.  A professor (also my adviser) would always say, “Water Bottles are the Devil!”  If you wanted to do well in her classes, you knew ahead of time that you’d better not come to class after stopping to get a Dasani from the vending machine!  When I first started at UVM I thought the majority of these “hippie” professors were a bit crazy.  However, they taught traditional engineering schooling while incorporating sustainable philosophy, and by the time I graduated I guess I, too, had become a bit of a hippie engineer.

The University of Vermont Graduation: I am the one on the right with the purple sash

Upon graduation I went to work in the public sector.  This was a wonderful experience in traditional engineering.  I had great managers and co-workers and was able to gain experience as a project designer and manager. I became more familiar with contract documents, design software and engineering judgment.  My manager noticed my passion for “green” and allowed me the opportunity to become involved in our work to become a more sustainable agency.   This included learning adaptation strategies that will be necessary for key infrastructure as the climate changes, design methods such as green and complete streets and using recycled or permeable pavement.  This experience was especially valuable because it allowed me to see just how difficult it can be to incorporate sustainable practices.  There are many important design standards that have been tested and proven over time.  To not follow these standards can be a scary first step, and sometimes is against local or national policy.  There are also environmental permitting and cost issues that can limit how many new “green” ideas can be incorporated into a project.

While working I took a class at the Harvard Extension School titled “Sustainable Buildings: Design and Construction.” In a multi-disciplinary environment, filled with people with a true desire to incorporate green practices, I learned about topics such as integrated design, LEED, air quality, rainwater harvesting, graywater use, and green roofs.  After attending “West Coast Green 2010” and hearing several incredible speakers including Bry Sarté discuss sustainable engineering, I knew that I wanted to help spread the Green Movement and become a part of sustainable engineering progress.

USGBC LEED Certification: Genzyme Building in Cambridge, MA

I feel it is important both personally and globally to transition to more sustainable practices.  I am a fairly environmentally friendly girl:  I purchase many green products, follow a vegetarian lifestyle, try to use as little energy and water as possible, commute via bike, bus or car-pooling, and carry a Lifefactory Water Bottle everywhere I go.  However, I also enjoy a few luxuries and feel that everyone should be able to indulge a bit and still be a friend to the planet and all of the other people with whom we share it.  At “West Coast Green 2010” William McDonough gave an incredibly inspiring keynote speech.  The message I took home from his speech was that we can not just make the world “a little better” but need to make drastic changes so that we will have enough resources for a rapidly growing population to live luxuriously in both developed and developing countries.

I believe that engineering design must become greener so that we live sustainably and do not deplete the world of valuable resources, so that the world’s inhabitants are living in a healthier environment. We must do this in a way that is not more expensive than traditional engineering options.  Bry Sarté’, in his book Sustainable Infrastructure: The Guide to Green Engineering and Design, sums it all up by saying  “Sustainable design, then, becomes the art of satisfying the same human needs with less energy and materials by increasing efficiency, and also reducing the environmental impact of the energy and materials we do use.”

Over the next several months I hope to learn and share about all things related to sustainable engineering.  I plan to finish reading Sustainable Infrastructure: The Guide to Green Engineering and Design and study for the LEED Green Associate exam.  I want to learn more about integrated design, rainwater harvesting and policies in different countries regarding water re-use.  I am currently living in Lake Tahoe where the “Keep Tahoe Blue” slogan is a very important part of life.  I hope to talk to different businesses about the new Best Management Practices that they need to implement in order to be environmentally friendly.

Beautiful Lake Tahoe- which we need to "keep blue!"

I am sure that as I learn more, new ideas will snowball into in-depth new topics regarding sustainable engineering and water resource management.  I hope that I will learn and share interesting and helpful information for all of our readers and hope to develop a relationship where we can all gain knowledge from each other.  I look forward to hearing your thoughts and ideas. I hope this blog will become a forum where we can all share lots of new ideas!

Looking forward to learning with you,


Taking Action!

October 26th, 2010 by

The following video, made by Corbin Halliwill, will be shown in high schools in San Francisco to increase awareness around environmental issues. See his previous post here.

An analysis of water quality of Ghana’s water sachets

October 14th, 2010 by

The following article was written by Claire Wang, a field researcher at Sherwood Institute and a senior at Columbia University pursuing a Bachelor of Science in Civil Engineering, on her recent work with Engineers Without Borders during the summer of 2010.

“Pure water!  Pure water!” As we inch slowly along the bumpy road amidst an awful traffic jam, women and children walk up and down by the cars, finding drivers and passengers to buy cold plastic sachets of “pure water” from them. Cold, five hundred-milliliter bags of water sit in a basin on their head as they peek through the windows for thirsty customers.

Bagged satchets of water are commonly sold in Ghana. Image: Ghana Business News

The plastic bagged water is Ghana’s version of a cold water fountain or a bottle of water—quick, cheap and refreshing.  Without the infrastructure to conveniently fill up your own bottle with clean water, nor the money to purchase a bottle of water, people purchase these water sachets when in need of a cold drink.  One bag, containing 500 mL, costs less than five cents—so what’s not to like about it? The problem is that the so-called “pure water” is not actually as pure as it sounds.

A study conducted by the University of Ghana over 27 different brands of sachet water showed that 77% contained pathogenic parasitic organisms.  This is very unfortunate, especially because sachet water was introduced in order to provide clean and cheap instant drinking water to people in Ghana.  Possible reasons for the contamination are sited in the study as “improper processing and purification procedures, unhygienic handling after production, the small size of the pathogens which enable them to escape filtration and the resistance of these pathogens to physical water treatment agents and disinfectants”.  Though I had known vaguely about the substandard quality of Ghanaian sachet water, I did not understand its severity until it was compared to water from a borehole in rural Ghana.

The purpose of my trip to Ghana this past summer was to work with the village of Obodan through Columbia University’s Engineers Without Borders.  One of our projects currently in progress is a water distribution system, which will be sourced from an Artesian well approximately thirty meters deep.   We expected this water to be contaminated, not only because the general rule of thumb for travelers on drinking water in developing countries is never to drink from wells, but also because research showed that water in the city of Kumasi was contaminated by traces of human waste due to poor waste management.  Thus, our impression on Ghanaian groundwater was that it was unsanitary, and we thought that sachet water would be cleaner than borehole water.

An artesian well in Ghana

We were careful with the water we used—ensuring that we only drank from sachets or bottles, and used only that water if there was any  chance of ingesting it—for dish-washing, brushing teeth, washing fruit and vegetables, and cooking.  We used borehole water for everything else—bathing, rinsing dishes (the primary rinse before actually washing), washing clothes.  Sachet water could be purchased cheaply and borehole water was free, but fetching borehole water involved a few minutes’ walk to the source and then a good workout carrying the water back.  We saw water in a completely different way than we usually did.  It became something we had to work for, even though it was still a basic human need.  On days with heavy rain, we’d harvest the rainwater from our roof to use for dish-washing and bathing, saving us a good number of trips to the borehole.

Rainwater is commonly harvested in plastic tubs for dishwashing and bathing

When we conducted our own field tests, they qualitatively showed the presence of bacteria in sachet water, like the study by the University of Ghana.  What surprised us more was that the borehole water proved to have little to no bacteria, according to both our own field test and analysis by the Water Research Institute of Ghana.   Although we did not have sachet water quantitatively analyzed against our borehole water, the photo shows the difference in coliform levels between the two types of water.

Analysis of borehole water quality

Analysis of sachet water quality. Bubbles and gel floating above the liquid indicate presence of coliforms.

The reason for the relatively good quality of Obodan’s borehole water may be that it is under a confined aquifer, which not all villages are lucky to have.  Some have dysfunctional boreholes or no boreholes at all, and must fetch their water from a stream instead.  Having such clean water means that treatment for the distribution system will not need to be elaborate and therefore will be much cheaper.

Our borehole water…was cleaner than the sachet water? Was our water purer than “pure water”?!  Was cooking with sachet water actually a mistake?  We actually started to wash our dishes with only borehole water, but continued to drink sachet water, though I did take a few sips from the borehole on my last day.   Perhaps the sachet water isn’t so pure, but there is something that we could call close to pure.

China’s Climate Emissions Global Issue; Water Scarcity Greater Domestic Priority

October 11th, 2010 by

On October 7th, published an article entitled “China’s Climate Emissions are a Global Issue, But Water Scarcity is a Greater Domestic Priority”. The article is extremely comprehensive in its reporting on China’s recent economic growth, the water-energy nexus, and issues that will be key to China’s future development and well-being. Below are some quotations from Keith Scheider’s article:

… the Natural Resources Defense Council, in a new report that looks at various scenarios of economic growth and China’s ability to diversify its energy sources, still projects that China’s carbon emissions will essentially double by the end of the decade.

The effect of China’s surging growth in coal production has even more dire consequences for the nation’s water supply.

“People outside China talk about emissions,” said Fuqiang Yang, director of the World Wildlife Fund’s Global Climate Solutions project in Beijing. “Inside China, water is the highest priority.

Municipal and domestic [water] use has been stable at around 12 percent [of total water usage], and industry uses 23 percent; 80 percent of that is used to operate and cool China’s 10,000 coal-burning generating units at 550 power plants.

China is the largest consumer of coal in the world. As of 2006, 68.7% of electricity was generated from coal. Image:

A Film For 10.10.10: Global Work Party

October 9th, 2010 by

The following film by Corbin Halliwill is a sneak peak into his work with Sherwood Design Engineers and the Sherwood Institute toward‘s effort to reduce the global carbon footprint. More information about Corbin’s project can be obtained here.

A Film for 10.10.10 from Corbin Halliwill on Vimeo.

LEED in China

October 8th, 2010 by

August 30th, 2010 was the 20th anniversary of the opening of the China World Trade Center in Beijing. It was also the grand opening of the new tallest building in the city—the China World Trade Center III, winner of the Leadership in Energy and Environmental Design (LEED) Gold Standard for its energy efficiency. The China World Trade Center III, which joined the directory of LEED certified buildings in May of 2008 under the Core and Shell 2.0 standard, features energy-efficient LED lighting structures and “fritted glass and metal fins” to conserve energy and direct sunlight, maximizing indoor lighting. The building, a project designed by Skidmore, Owings and Merrill SOM and engineering company Arup houses commercial space, restaurants, a hotel, and recreational space in addition to a rooftop pine garden and waterscapes that are open to the public.

The China World Trade Center III was opened on August 30, 2010. Located in Beijing's bustling Central Business District, it is not only the city's tallest building, it is also LEED certified. Image:

The China World Trade Center III is one of many new projects in Beijing that have caught the public eye for the utilization of LEED standards in design, construction and operation. In 2006 China Dialogue reported that the first LEED project in China—the ACCORD21 Building—was completed in western Beijing in 2004. The 10-story office building utilized 70% less energy than buildings of a similar size and saves 10,000 tons of water a year. The report mentioned that in all of China, as of the time of writing (2006), there were only three other LEED certified buildings, located in Suzhou, Harbin and Shenzhen. The China Dialogue article also mentioned a few projects in construction in Beijing, one of which was the Modern MOMA complex, also known as the Linked Hybrid by Steven Holl, which was completed in 2009. Linked Hybrid is one of the largest residential complexes in the world to utilize a geothermal heating system.

The China Business Review provides a comprehensive analysis of the green construction industry and LEED buildings and consultation services in China. Since the time of the CBR article’s writing, the “green bar” in China has been raised even higher, especially with China’s commitment to improving its air and water quality. Lower energy requirements translate to a reduced use of power that is mostly generated by fossil fuels. Water-conserving and harvesting installations are appealing in a country that is water scarce. There definitely is economic incentive in sustainability. However the dialogue on how effective green building regulation given China’s national situation is divided: although intentions are often good, it is still relatively more difficult to obtain appropriate, standardized building materials in Beijing than in New York, there is often miscommunication between design and engineering companies and construction firms, and fundamental misunderstandings of the “green building” concept.

Steven Holl's Linked Hybrid (Beijing) utilizes geothermal energy for heating and collected rainwater for its water and landscapes.

In preparation for the 2008 Beijing Olympics, China made a big push for more energy and water efficient buildings, despite the China Ministry of Construction’s former dislike of the word “green”, which had (and in many cases, still continues to be) falsely utilized to give new projects a feeling of modernity without adopting the appropriate techniques to ensure a standardized level of sustainability. The LEED standards are more and more filling the role of standardization in China. From the few LEED certified projects documented in 2006, the official LEED directory now officially lists 48 projects in Beijing alone. The growing number of companies seeking LEED certified engineers and foreign collaborators on green construction projects are a testament to LEED’s acceptance as a standard of the future of construction and planning in China.

Yamanashi, Japan: water, plastics, recycling, resources

September 24th, 2010 by

I filled my glass with clear water from the kitchen tap. As I watched the moisture condense around the cup, I wondered about where the sweet, cool tap water came from. This was no ordinary city tap. I was living in a guesthouse at a farm in Yamanashi, a Japanese prefecture bordering the western edge of Tokyo. I would spend two weeks living on this farm with a group of students from around the world, doing volunteer work for the farm owner and getting to know the local community.

I asked the farm owner where our drinking water came from. He explained to me that the water came from a spring in the mountains above the farm. Furthermore, the water received no treatment before we drank it. The pristine water simply flowed through a pumping station and arrived at our taps.

Yamanashi is located just west of Tokyo. The prefecture is famous in Japan for its fruit crops. (Image from

Yamanashi is famous throughout Japan for its fruit and fruit products; the prefecture produces more grapes, peaches, and plums than any other prefecture (fruits make up half of its agricultural production). Much of the land is undeveloped; roughly 1/3 of the prefecture consists of protected “natural parks.” A vast network of natural rivers and streams provide farmers with abundant water.

The Rise of Bottled Water

Yamanashi is also famous for its water. In 2005, Yamanashi shipped nearly ¥14.8 billion (approximately $144 million in present day dollars, accounting for inflation) in mineral water. This activity accounted for 23.5% of the national revenues from mineral water that year.

Many people in Japan appreciate mineral water for its therapeutic and medicinal properties (whether or not the water actually possesses these properties is another matter). Thousands of public bathhouses called “onsen” are scattered throughout Japan. These onsen provide people with large spas full of mineral water, and different onsen offer different waters. Some onsen offer water rich in sulfur, others in metals like iron, and others in bicarbonate. Locals often bring water jugs to the onsen so they can bring some of the water back home for future drinking or bathing.

Spas called "onsen" are popular throughout Japan. People visit onsen to bathe in mineral waters. (Image from

Bottling companies have taken advantage of Japan’s well-established mineral water niche. According to the Japan Mineral Water Association, bottled water sales surged from 414,800 kiloliters in 1993 to 1,374,500 kiloliters in 2002 –an increase of over 230% in under 10 years. The per capita consumption of bottled water was 3.3 liters in 1993 and 10.8 liters in 2002. In 2001, Japanese consumers could choose from nearly 450 domestic brands and 50 imported brands of bottled water. Until visiting Japan, I had never heard of bars serving more than a few brands of bottled water. At a bar in Shibuya, you can apparently choose from some 48 brands of water.

Japan’s bottled drink industry, let alone bottled water industry, is huge. In Tokyo I never found myself farther than a block from a beverage vending machine. In 2003 there were 2.6 million beverage vending machines on the streets of Japan. Most drink vending machines sell bottled mineral water, soda, juice, tea, vitamin and electrolyte water, and even coffee. Nearly all of the drinks are sold in polyethylene terephthalate (PET) #1 plastic bottles. Once you are done with the drink, you are supposed to drop the PET bottle into a recycling bin.

Plastics Abound

All numbers are derived from information in the Japan Plastic Waste Management Institute’s 2004 publication “An Introduction to Plastic Recycling.”

About 14.5% of Japan’s mechanically recycled plastic waste comes from PET bottles alone (mechanical recycling is the conversion of a waste material to other useful materials). In 2004, Japan mechanically recycled 1,520,000 tons of plastic –220,000 tons came from PET bottles. About 15% of Japan’s total plastic waste was mechanically recycled that year. Roughly 45% of total plastic waste was disposed in landfills or simply incinerated without energy recovery, and the nearly 40% remaining was used to produce fuels or burned to produce energy. More recent data is unavailable, but present day recycling, disposal, and incineration rates are likely to be similar.

Important 2004 values:

  • 9.9 million tons total plastic waste produced
  • 1.52 million tons of plastic waste mechanically recycled (15% of total)
  • 1.73 million tons of plastic simply incinerated (18% of total)
  • 2.76 million tons of plastic disposed in landfill (28% of total)
  • 3.89 million tons of plastic used for fuel and energy production (39% of total)

Shocked by the Japanese numbers? When you compare plastic waste production in Japan to plastic waste production in the United States, Japan doesn’t look so bad. According to the US EPA, the US produced 28.9 million tons of plastic waste in 2005. Just 1.65 million tons of this waste was recovered for recycling (less than 6% of total plastic waste).

Japan’s plastic recycling rate is more than double the United States’ recycling rate (by mass).

The Environmental Cost of Bottled Water

Bottling water into plastic containers has environmental costs. According to the Pacific Institute, producing the bottles for the American bottled water market required “the equivalent of more than 17 million barrels of oil, not including the energy for transportation.”

Some facts about bottled water, according to the Pacific Institute:

  • Manufacturing one ton of PET produces about 3 tons of CO2 emissions.
  • Three liters of water are required to produce one liter of bottled water because bottle production also requires water.
  • It takes about 3.4 megajoules of energy to make an average one-liter plastic bottle.

If one simply must obtain mineral water (it is a product, after all), then bottling is the best available way to get it. Bottling distant waters and shipping them to your local store is more efficient than personally traveling across the world to try the water at the source. But do we really need to drink mineral water? Bottled waters may not be as safe and healthy as people say they are.

Click here for a detailed list of bottled water recalls in the United States. Some bottled waters were recalled for mold, odors, and even cricket contamination.

Mata ne! (Japanese for “see you next time!”)

Pictures from an “Eco-resort” near Beijing

September 9th, 2010 by

A few weeks ago, I visited an eco-resort outside of Beijing. The resort promoted fishing and freshwater crabbing in stocked ponds, but when I ventured to a far corner of the man-made pond, I saw about a dozen dead fish floating in the water. Here are some photos:

Fountains, presumably used for increasing levels of dissolved oxygen in a man-made fishing pond

They were cultivating duckweed in enclosed areas of the pond. Maybe it was being used for excess nutirent (nitrogen and phosphorous) removal from ponds receiving reclaimed wastewater

Dead fish in the fishing pond

More dead fish. The resort cleans and cooks fresh catches from this pond to serve to visitors of the eco-resort.

Eco-travel, eco-vacations, and eco-resorts are all hot words right now in China, which is good, in that people are starting to be more aware of the importance of nature. But images like the ones above are a reminder that along with the new vocabulary, some major improvements need to be made in the actual quality of the environments here. Guests should be aware that sometimes, the letters “e-c-o” in front of something may not have much meaning.

Agricultural management in the Tai Lake region

September 6th, 2010 by

Following the conversation from the eutrophication of Lake Tai (Taihu), probably the most publicized Chinese eutrophication event in Western media,  many will probably want to know more about the sources of the excess nutirents leading to massive algal blooms and deteriorating water quality.  In February, the New York Times reported that previous information on the extent of the deteriorating surface water quality in China severely underestimated the scale and influence of agricultural runoff, focusing mostly on point sources such as industrial effluent. Ma Jun, director of the Institute of Public and Environmental Affairs, a nonprofit research group in Beijing, rightly pointed out in the article that pollution emissions stemming from millions of rural farmers will prove an even bigger challenge than slapping fines on factories and industrial sources. But,  China’s Ministry of Environmental Protection is now beginning to realize that the agricultural contribution to poor surface water quality is just as prominent as the industrial contribution. Here I will give a brief overview of the issues at hand, from the perspective of nitrogen as an excess nutrient pollutant stemming from agricultural sources. In a previous post, we identified the main source of total nitrogen content in Lake Tai as having an agricultural origin.

In contrast to Europe and the United States, which could both be argued to have undergone agricultural intensification over a period of centuries, in China, the shift from traditional, complex, labor-intensive farming systems based on nutrient recycling happened over about four decades. Now, China’s agricultural system as a whole is heavily dependent on introduced inorganic nitorgen fertilizers and  is utilizing less and less organic and green manures to replenish nutrients that are removed from agricultural soils when crops are harvested. The agricultural scheme utilized in the Tai Lake region is one of the two most intensive double cropping systems in China: summer waterlogged rice followed by winter upland wheat.

The nitrogen cycle. NO3 is subject to leaching, especially when soil experiences prolonged waterlogged conditions, and volatization, espeically in temperatures over 90 degrees Fahrenheit.

Generally, inorganic nitrogen, which, in the case of China, is usually introduced to fields in the form of urea-based fertilizers, is quickly converted into ammonium (NH4+) and later into nitrate (NO3-)  by microorganisms in the soil according to the normal function of the nitrogen cycle. A portion of the nitrogen is also lost by NH3 volatization to the atmosphere, which contributes to air pollution and acid rain. Most plants, including rice and wheat. more readily take up the nitrate form of nitrogen than they do the ammonuium form. However, due to the negative repelling charge of nitrite with the surrounding soil (especially if the soil’s content is high in clay), the nitrate form is also highly mobile in soil and is easily carried by percolating water into surface water or groundwater.  Ammonium, on the other hand, sorbs to clay and organic matter, and although is less readily absorbed by plants, is held in soil for a prolonged period of time if not further converted to the nitrate form. Organic nitrogen supplements, including proteins or amino acids found in animal waste, are a slow release source of nitrogen for crops, as organic nitrogen  must first be converted into its inorganic forms in order to be taken up by plants.

Nitrogen that is quickly converted from urea fertizlier into nitrate is lost by leaching through soil into water.  Studies on the intensive wheat/rice double crop cycle followed in the Taihu region show that alternating wheat and waterlogged rice leads to an accumulation of nitrate after the wheat season. However, flooded rice fields in the following season results in much of the nitrate being lost by leaching. (Ju et al 2009) Farmers in the Tai Lake region also tend to use more fertilizer during the wheat season than wheat farmers in northern China, but result in lower grain yields. A possible explanation is that Tai Lake region farmers try to use increased amounts of fertilizer to compensate for poorer wheat cultivation conditions.

Traditional rice field flood cultivation methods result in the picturesque scenes typical of the Chinese countryside, but may also result in increased leaching of nitrogen into surrounding water bodies

Much of the problem of nitrogen leaching lies in agricultural practices . One- poor wheat-growing conditions in the Lake Tai region lead farmers to overuse fertilizers (with little to no effectiveness achieved in crop gain) during the wheat season, and two- the traditional use of flooded rice paddies promotes nitrogen leaching.  We can see here that one aspect of the problem is psychological: with farmers holding to the belief that increasing inorganic fertilizer use will lead to increased crop yields. The other aspect is technical.

The System of Rice Intensification (SRI), developed in 1983 by Henri de Laulanie, a French agricultural practioner living in Madagascar, is one method that has been utilized worldwide to increase rice yields with fewer water and fertilizer inputs.  One key aspect to SRI is that, unlike traditional rice cultivation methods, rice plants are not kept under waterlogged conditions, but instead, rotated between wet and dry conditions. Alternating between wet and dry causes cracking of the earth, promoting aeration of the soil, increased root growth, and slower leaching of nitrogen from the topsoil. The wider root systems of each individual rice plant is then able to take up more of the applied nutrients (nitrogen) from the soil, resulting in healthier plants with more tillers, and better yields. In Sichuan Province, farmers have achieved 40% greater yields using SRI, with less water and nutrient inputs.

However, as China has a rice cultivation history that spans thousands of years, urging farmers to change their flooding methods will continue to be a difficult task. This, coupled with the relatively recent introduction of inorganic fertilizers and their overuse will probably be the biggest challenge in reducing the contribution of agricultural sources of nitrogen to water deterioration in the Tai Lake region. Experts (Want et al 2006, Richter et al 2000) have recognized the need to the economic “internalization of environmental externality”, calling for measures such as the removal of government subsidies on agricultural fertilizers (reducing over application of nitrogen to fields) and improvements on water pricing and water rights legislation (reducing unneeded water usage by adjusting prices to reflect the costs of using the resource and reflecting the needs of water quality improvements).

Studies cited:

Richter, et al. 2000.  “The N-Cycle as determined by intensive agriculture– examples from central Europe and China” Nutrient Cycling in Agroecosystems.

Wang, et al. 2006. “Toward Integrated Environmental Management for Challenges in Water Environmental Protection of Lake Taihu Basin in China”. Environmental Management.

Introduction to Taihu

August 23rd, 2010 by

Lake Taihu (太湖), also called Tai Lake, is the third largest freshwater lake in China. Although it began receiving widespread coverage in the western media after a major algal bloom that covered 1/3 of the lake’s area in 2007, killing fish and disrupting surrounding areas potable water supply, the lake has been experiencing a decline in water quality for the past 20 years. The lake is located on the southern part of the Yangtze in southeastern China and is administered jointly by Shanghai Municipality, Jiangsu Province and Zhejiang Province, serving as a floodwater basin, irrigation supply, drinking water source, aquaculture base and tourist attraction. It is the major source of drinking water for the municipalities of Wuxi, Suzhou and Shanghai. The algal outbreak in 2007, called a “natural disaster” by government officials, caused a noticeble drop in water quality for local residents, who said that they could smell the stench of the algae on their bodies after showering, and were forced to rely on bottled water for drinking.

In the summer of 2007, Lake Tai suffered from a major algal bloom that resulted in a fish kill and no tap water for one week for millions of local residents (source:

During the last 20 years, the rapid urbanization of the areas surrounding Taiju, coupled with ineffective management and technical support, have not only caused the eutrophication of the lake, but also its contamination with organic substances and ecological destruction. Now, many doubt the lake’s water quality to ensure safety of the millions who rely upon it as a drinking water source. The water quality of the lake was rated I or II according to China’s National Surface Water Standard up until the 1970s. By the late 1980s the quality had fallen mostly to class III, white in some parts, it reached IV and V. In the late 1990s the lake rated an overall class IV, with approximately one-third of the lake as class V. Lake Tai has become a symbol of water environmental protection, which is a high-priority issue for government at all levels.

Government Five-Year Plans have continued to make Lake Tai an issue of major importance. The Ninth Five-Year Plan (1996-2000) proposed 54 domestic wastewater treatment plants and sewage conduits were planned to be located in the basin. Later however, only 29 plants were completed or partially completed by the end of the period. The Tenth Five-Year Plan (2001-2005), 81 domestic wastewater treatment plants were expected to be built or explanded by 2005. The goal was to be reach over 70% treatment of domestic wastewater. In addition to building more wastewater treatment plants in the Taihu Basin, other measures have also been taken in an attempt to abate the spread of noxious blue-green algal blooms, including releasing algae-eating fish into the lake, physically hauling algae out of the lake, and crackdowns on government corruption in enforcement of effluent standards.

While good intentions obviously exist for the future of Lake Tai, implementation has been difficult and the water quality in the lake has not risen significantly. The main problem of Lake Tai’s pollution issue is the algal blooms. Overgrowth of algae is caused by water that is rich in nutirents (nitrogen and phosphorous), that are usually the limiting factors in algal growth. With nitrogen and phosphorous existing in surface water in excess, algae growth becomes almost limitless, just waiting for the right temporal conditions to cause an extensive bloom. And, when algae goes into respiration conditions at night and when dead algae is digested by microorganisms, the amount of dissolved oxygen in the surfacw water can be virtually depleted, causing fish kills and decrease in biodiversity. According to reports, the major sources of nitrogen and phosphorous in surface water are industrial effluent, domestic wastewater treatment plant effluent, and agriculture. Each type of effluent into surface water has different characteristics; for example, household wastewater is a greater contributor of phosphorous and ammonium (NH4+), while agricultural runoff is a greater contributor of nitrate (NO3-). Below, we can see the contributions of pollution sources Industry (Ind.), Household (Hou.), and Agriculture (Agr.) to the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorous (TP) in Tai Lake. The figure shows that the main contributors of the pollution of Tai Lake have become household discharges and agriculture.

The main sources of excess nutrients nitrogen and phosphorous in Taihu are household discharge and agricultural runoff. (source: Wang et al, 2006)

In response to industrial and municipal contributions of nitrogen and phosphorous to surface waters, China’s Five-Year Plans are right to regulate large industries and build more, or retrofit, wastewater treatment facilities (most current wastewater treatment facilities in China do not include tertiary treatment processes that remove nutrients nitrogen and phosphrous from the effluent). Recent banning of phosphorous-containing detergents is another example of effectively reducing the household discharge contribution to the Tai Lake pollution problem.

In my next post, I’ll address agricultural runoff (fertilizers) contribution to the condition of the Tai Lake Basin.

?Source:  Wang Q et al. 2006. “Profile: Toward Integrated Environmental Management for Challenges in Water Environmental Protection of Lake Taihu Basin in China” Environmental Management Vol. 37, No. 5, pp 579-588.

Water and Power in Uganda

August 17th, 2010 by

This is the second of three blog posts from Sherwood’s Michael Thornton, currently based in Uganda.

Ogamba ki!  This weekend I visited Jinja, home to the largest power production facility in Uganda, the Nalubaale and Kiira hydro electric plants.  I was able to get a decent picture of the dam this year (below); last year I was stopped by AK-47 wielding guards very angry about my camera.  The reason they were so angry is that the twin dams presently produce over 60% of the nation’s electrical power and interruption of either would be devastating.  The remainder is produced from an assortment of smaller thermal and hydro plants, none larger than 50 MW.

Nalubaale Hydroelectric Power Station – Together with the Kiira Power Station provides 380 MW during maximum flow.

Power is used in Uganda for the usual assortment of things, though at a much less intensive level than we in the US are used to.  In wealthier areas it’s common to have lights, refrigerators, computers and televisions but in most of the country there is no power except at central points.  Facilities are then limited to light bulbs, basic refrigeration, cell charging and other basic technology.  While power is not ubiquitous, cell phones seem to be.  A report in 2008 stated that Uganda is the first African country in which there are more cell phones than fixed telephones. In 2008, it was reported that 39% of the population owned cell phones and that by 2014 it is estimated that cell phone penetration in Uganda will reach 70%.  Kiosks such as the one pictured here charge cell phones for a fee.

Phone Charging – In many cases a household will have a phone well before a single light bulb. They may charge them at kiosks like this for a small fee.

Illegal Power – Power lines are often tapped illegally to power small kiosks or shops.

Uganda is a well watered country in most regions and suffers, more than anything, from lack of infrastructure and development.  Although 13% of Ugarda is covered in wetlands, lack of national conservation laws have resulted in a decline in biodiversity in recent years. Most villages, such as the one I am working in, have pit latrines and open ponds or shallow wells for their wastewater and water facilities.  The country receives ample rain, having two wet seasons and two dry seasons about three months long each.  Water is generally available regionally, though often undeveloped making it far or unclean. According to a UNESCO report in 2003, only 59% of the rural population had access to clean, safe drinking water. National urban water coverage is up to 65%, up from 54% in 2000.

Hand Dug Well – This well reached over 120’ before being partially lined with bricks and capped with a hand pump. An expensive solution funded by a local mosque, this well costs 7 million shillings ($3500). Diggers (pictured at rear) are armed with a pick axe and lowered by rope into the hole.

Originating at Lake Victoria to the south east, the Nile River feeds much of Uganda and, as noted above, provides the vast majority of its power.  During times of low rainfall, which Uganda has been experiencing more and more due to climate change, the water level in Lake Victoria falls and with it the output of the main power stations.  As a result and especially when compounded with poor general infrastructure, rolling blackouts are common.  While I was here last summer many parts of the capital city received power every other day.

Looking forward, there are many new power stations planned, most of them relying on the flow of the Nile.  Due to be completed in the next year, the 250 MW Bujagali Hydro Power Station will drastically improve national production.  It comes at the cost of the Bujagali falls, a culturally important land mark and ecosystem and center of some of the best whitewater rafting in the world.  Many in Uganda have protested this station, bringin up issues ranging from an unfair bidding process, to concerns that the natural ecosystem will be destroyed, to questions about how climate change-induced drought make reliance upon hydropower unwise, but it will be completed soon regardless.

Climate change is happening now in Uganda.  I talked with some farmers who have said they don’t know when the traditional wet and dry seasons will occur any more.  Some are planting now, some are harvesting.  Mid-august, typically a wet time in Ddegeya has been bone dry with only a few sprinkles barely reaching the ground for the last 3 weeks.  Today I watched as a landowner cluck clucked a crop of coffee ruined due to lack of rain.  Equally challenging is the country’s rocketing population growth.  With a present population of 34 million in an area smaller than Oregon, it is already a tight place to survive on subsistence farming.  Hills far steeper than seem possible are home to farms and houses.  With the world’s second highest population growth rate of 3.6% per year (over 50% of the population is under age 15 and average births per mother are over 6) and a rising level of consumption and environmental impact, Uganda has a daunting infrastructure and resource challenge ahead. Reports have stated that rapid population growth coupled with climate change (resulting in droughts and flash flooding), water borne disease and poor health infrastructure are some of Uganda’s main current issues.

Crop Fire – Weeks without rain and trash burning lead to many small fires, in this case consuming a dried crop of corn. A young boy attempts to beat out the fire.

Next week I’ll take a look at the projects EWB MIT is working on to address some of the challenges above in our village and provide a brief outlook on Uganda’s future from my perspective.  Send questions as you have them!

Oli otya from Ddegeya, Uganda!

August 10th, 2010 by

The following post was written by Sherwood’s Michael Thornton, currently based in Ddegeya, Uganda.

For the next three weeks I’ll be reporting from here as I continue my work with the MIT chapter of Engineers Without Borders.  We’re here in Ddegeya in the second year of a five year project to enhance the quality of life of this rural village of about 1,000 through enhancements to the village’s water and power infrastructure.

MIT EWB team member, Bryan, with some of the many reasons we are here!

The MIT EWB chapter (check out their blog HERE) has done an amazing job assessing the base conditions, researching solutions, gathering stakeholder input and planning designs.  The purpose of this trip is to implementation; in this case meaning installing a 1.4 kW solar system, testing and fixing boreholes and testing homemade sand filters and the flocculation capacity of a local seed from the meringe tree.  This is my second trip to Ddegeya; last summer with the Sherwood Institute’s backing I spent three weeks here performing a pre-site site analysis review of the village, its resources and environment.  For those interested, I’d be happy to send around the report from this visit.  This trip finds me with a team of six members of the MIT EWB chapter as their trip mentor; basically an in-field professional responsible for overseeing all works.

In a later post I’ll go into more detail about the work we are doing.  First, some background:  Ddegeya is a rural village in south central Uganda, in the Masaka province.  As you can see from the photos it is minimally developed and has a warm, dry climate.  Uganda is one of the poorest nations in the world; its total GDP is equal to approximately 2-3 quarters of Apple’s revenue.  Located a few miles from the equator, its seasonality is dominated by wet and dry cycles; its elevation (average 1206 meters in Kampala) keeps it relatively cool despite its equatorial location.  Despite its poverty, it’s also a beautiful country with amazing people and a relatively stale government and rapidly developing infrastructure.  Helping development here is helping the whole of Africa.

Typical Ddegeya Residence

The Engeye Health Clinic, Ddegeya, Uganda

I am staying at, and much of our work is centered around, the Engeye health clinic a level two health center that is unable to offer many basic services due to lack of refrigeration and steady clean water.  Part of EWB MIT’s goal is to solve these issues.

Presently there is no legal electricity in the village (one or two stores have tapped a transmission line for soda boxes) and water comes from a single shallow borehole and pond, seen below.  The water from the borehole (fixed during my summer visit last year) is relatively clean, though insecure at only 20’ depth.  The water from the pond is filthy and a regular disease vector, as water is in much of Uganda.  The community sometimes boils water; sometimes does not.  In addition to suffering from water born illnesses, many members of the community must walk miles to the borehole; taking valuable time and energy from their days and practically limiting the amount of water available to each family.  Daily per capita water consumption is somewhere around 15 liters.  Finding and developing more distributed, cleaner sources is of primary importance to the development of Ddegeya.

Existing Water Sources: Open Pond and Repaired Shallow Well

In the next post I’ll explore Uganda’s overall water / power situation and in the final post will provide more detail about the works we’ll have hopefully completed and the outlook moving forward.  So stay tuned, and please post any questions you may have and I’ll do my best to answer!

A Closer Look at Water Issues in Bangalore

August 9th, 2010 by

A study taken by the Centre for Symbiosis of Technology, Environment, and Management (STEP) approximated that 40% of the population of Bangalore is dependent on groundwater. There are around 125,000 private bore wells in the city. Because the extraction of groundwater is highly unregulated, the water tables have been rapidly depleting. According to R. Vasudevan, a chief engineer of the Bangalore Water Supply and Sewerage Board (BWSSB), the water levels have dropped 300 feet below ground level. The BWSSB extracts the majority of the water they distribute from the Cauvery River. This river is located almost 100 km away from the city and at an altitude of about 1,500 feet below that of the city. Because of this, approximately 75% of the total BWSSB revenue is spent on electricity charges. Another huge problem exists – almost 30% of the water extracted is lost to corroded and broken piping systems.  The piping system in the city is over 50 years old. Many of the pipes are in horrible condition, producing many leaks. Unfortunately, the BWSSB has only made temporary fixes to repair the decaying pipes rather than to replace them entirely.

The queue in a public water tap

With such water shortages looming over the city, it is essential for changes in the water policy of the city to take effect. The BWSSB has just mandated rainwater harvesting last year as an amendment to the Bangalore Water Supply and Sewerage Act of 1964. The amendment states that all buildings with a total rooftop area of 2400 square feet or greater must install a rainwater harvesting system; all proposals for buildings with a total rooftop area of 1200 square feet or greater must include plans for a rainwater harvesting system. In order to see how effective rainwater harvesting can be, I have prepared a basic water balance of the city. The following values necessary for a balance were found. Some of the metrics were determined by simple calculations.

Rainfall Data:

Area of the City

709,500,000 m2

Amount of Average Rainfall

0.859 m

TOTAL Amount of Rainfall in the City, Annual

609,460,000 m3

Water Demand Data:

Per Capita Water Demand*

150 L/person/day

Population of the City

5,840,155 persons

Water Demand for Domestic Use, Annually

319,748,486.3 m3

Daily Water Demand for Other Uses**

587,000,000 L/day

Water Demand for Other Uses, Annually

214,255,000 m3

TOTAL Water Demand, Annually

534,003,486.3 m3

*Please Note: This value is standard set by the Central Public Health and Environmental Organization. However, this is an overestimate of the per capita water use daily. Studies show that many people use only around 100 L of water per day.

**Please Note: This value encompasses the demand for commercial establishments, industrial users, institutional users, grounds (municipal and industry), fountains, and unaccounted for water (leakages). This data was gathered from surveys and interviews. The values were obtained from the Resource Optimization Initiative:

Eckelman, M. J., Shenoy. M., Ramaswamy, R., Chertow, M. 2010. Applying industrial ecology tools to increase understanding of demand-side water management in Bangalore, India. (unpublished manuscript).

If we look at the total amount of rainfall on the city and the total water demand, we see that the total rainfall is only slightly greater than the total water demand. We must take several things into account. First of all, it is not possible to capture 100% of the total rainfall. If we approximate that 70% of the total rainfall can be effectively captured to recharge aquifers, lakes, and bore wells, then the total water demand exceeds the amount of rainfall captured. This shows the severity of the water shortages in Bangalore. The numbers are too close to each other for comfort!

In order to alleviate the water scarcity issues, a greater campaign to install rainwater harvesting units should be invested in. People should be made aware of the advantages that rainwater harvesting can have. In addition, the BWSSB should work to expand their water reuse programs. Currently less than 1% of water is recycled for reuse. More sewage treatment plants should be installed to increase this percentage. There are many ways to solve this water crisis. Small steps can yield large results. Installing a rainwater harvesting system can be as cheap as 400 Indian Rupees (Approximately $8.50). The installation of such units will help both the people and the environment. The citizens of Bangalore can reap the benefits of sustainable water management while the environment can enjoy its water sources being replenished.

New Sherwood Book to be Published by Wiley

August 3rd, 2010 by

I am pleased to officially announce that my first published book about Sherwood’s work, “Sustainable Infrastructure: The Guide to Green Engineering and Design”, is being published by John Wiley and Sons and will be on store shelves this September! The book is a complete guide to integrating sustainable strategies into infrastructure planning and design, and it has been literally two years in the works. To give you a brief preview of what the book will contain, here is the table of contents:

Chapter 1: The Process of Applied Sustainable Engineering Design
Chapter 2: Sustainable Infrastructure Frameworks
Chapter 3: Water Conservation & Supply
Chapter 4: Integrated Water Management
Chapter 5: Energy and Greenhouse Gases
Chapter 6: Sustainable Site Planning, Built Systems and Material Flows
Chapter 7: City-Scale Approaches
Chapter 8: Applications for Sustainable Communities
Chapter 9: Building-Scale Sustainable Infrastructure

There will be two book launch parties, to be held at the AIA in San Francisco and New York City. For these events, which we are calling the Sustainable Infrastructure Summit, The Sherwood Institute and other sustainable infrastructure leaders will come together to host a forward thinking discussion. There will be a reception with a discussion and Q&A. We hope that you can save the date to attend these events and celebrate with us!

September 14, 2010:
AIA NY Panel Discussion + book signing reception
536 LaGuardia Place (in the Hines Gallery)
NY, NY 10012

September 22, 2010:
AIA SF Panel Discussion + book signing reception
130 Sutter Street (in the Gallery)
San Francisco, CA 94104

We hope you can make it, since in addition to these being fun events you won’t want to miss, you will also be the first on your block to see (and buy) the book in person. You can also pre-order the book on Amazon or direct from Wiley.

- Bry

Decentralized Wastewater Treatment, Puducherry, and Japan’s Johkasou

August 2nd, 2010 by

Two weeks ago we published an article describing the open sewage systems in Puducherry, a Union territory in South India. In these systems, wastewater from businesses and homes is simply released into the environment with little to no treatment. This release poses a threat to public health and local water quality.

The conventional method of wastewater treatment requires a network of pipes and sewer lines that feed into a centralized wastewater treatment plant. After treatment, the water is expelled to a nearby body of water or used as reclaimed water. The conventional method often requires a central authority (e.g. a city government) to organize construction of sewer lines and connect users to the public system. After that, the authority must ensure that the treatment plant continues to operate correctly.

It is challenging to build and maintain a functioning wastewater treatment plant. In the United States we often take the operation of wastewater treatment plants for granted –the US has a strong regulatory system which ensures that municipalities and governments keep their services running as promised. In countries with less accountability in government (a consequence of corruption, holes in public policy, civil unrest, economic problems, a weak judicial system, etc.), centralized disposal systems are difficult to implement successfully. In Ghana, for instance, many wastewater treatment plants are constructed and then abandoned after just a few years of operation.

One alternative to utilizing a centrally controlled conventional treatments system is utilizing a decentralized array of smaller treatment systems. According to Small & Decentralized Wastewater Management Systems, decentralized wastewater management may be defined as the collection, disposal, or reuse of wastewater from individual homes, clusters of homes, isolated communities, or parts of existing communities at or near the point of wastewater generation. By having an array of decentralized treatment systems, regions are less susceptible to a total failure of wastewater treatment. The failure of one centralized system will stop treatment on a large scale. The failure of one decentralized system will only affect a small group of people.

Japan’s Miniature Wastewater Treatment Plants: Johkasou

The Puducherry Pollution Control Committee has decided to adopt a solid waste management scheme similar to Japan’s model. In the realm of wastewater treatment, the PPCC should also consider one of Japan’s approaches to decentralized wastewater treatment: the “johkasou.”

Cutaway model of an average johkasou. (Image from the Japan Education Center for Environmental Sanitation)

A johkasou is a wastewater treatment tank. It looks like a septic tank, but it behaves like a miniature wastewater treatment plant. The technology that engineers have fit into these small tanks is impressive –a small-scale johkasou for an individual house might sport an anaerobic filter tank, contact aeration tank, sedimentation tank, and disinfection tank. All of these treatment tanks can be held in a main tank as small as 4 cubic meters, and once water undergoes johkasou treatment it can be used for non-potable applications or released directly to the environment.

According to the Japan Sanitation Consortium, johkasou require electric energy comparable to the energy needed to light a room (a system designed for 5 people will consume about 37 kWh per month –the same amount of energy consumed by a 60 W lightbulb kept on for 26 days straight). Johkasou are intended for areas with limited access to centralized sewage systems. Because the tanks require electricity to operate, they cannot be used in areas that lack reliable electricity supply.

Installing a johkasou typically requires one week of construction work. The cost to purchase and install a 5-person johkasou is about ¥860,000, or nearly $10,000. Depending on the region, the Japanese government has subsidized between 40% to 90% of this cost for homeowners and businesses interested in having a johkasou.

Why would the Japanese government subsidize up to 90% the cost for a small-scale system? Release of untreated wastewater into the environment can threaten the fishing industry and increase water treatment costs downstream. Also, threats to public health increase healthcare expenditures and can hinder productivity (sick people are less productive). The economic benefits of decentralized wastewater treatment coupled with a cultural desire to protect Japan’s environment make it appealing for the government to subsidize johkasou programs.

Is a conventional wastewater treatment system feasible in Puducherry? In 2007, only about 30% of the urban area had sewage service. The other 70% discharged wastewater to the environment via exposed channels or septic tanks.

The costs associated with the conventional system and the johkasou decentralized systems are high. One must study the Puducherry hydrology, its political climate, its economic system, and its culture before a decision can be made. Centralized systems? Or decentralized systems? Or both?

Roughly 35 million people in Japan were served by johkasou in 2005. This graph shows breakdown of Japan’s wastewater treatment sector over time. Notice how use of johkasou and public sewage systems expanded to cover the majority of the population. (Image from “Status of Onsite-treatment of Domestic Wastewater Management in Japan” by Yasumoto Magara; Environmental Risk Engineering Laboratory at Hokkaido University)

In 2005, 35 million people in Japan (about 27% of the country’s population) used johkasou tanks. The technology is widely used, and it may offer regions like Puducherry a way to clean its wastewater without centralized treatment systems. Other cheaper alternatives to the johkasou include natural treatment systems like treatment wetlands and ponds. Unlike a johkasou, however, a natural treatment system often requires more land area than highly urbanized areas can provide.

To learn more about johkasou use in Japan, visit the Japan Education Center of Environmental Sanitation website here.

Brief Introduction to Beijing’s Gaobeidian Wastewater Treatment Plant

July 30th, 2010 by

Beijing Gaobeidian Wastewater Treatment Plant is not only the largest of Beijing Municipality’s 15 wastewater treatment plants; it is also currently the largest wastewater treatment plant in China. It serves a population of 2.4 million people and has a daily capacity of 100,000 cubic meters (26.4 million gallons/day), processing about 40% of Beijing Municipality’s total wastewater volume. When the plant was built in the 1990’s, national standards for phosphorous and nitrogen in treated effluent had not yet been set, so that treated wastewater did not meet criteria for even the national level V (not suitable for use in agriculture) surface water standard because of high levels of nitrogen and phosphorous. Since then, the plant’s secondary treatment facilities are undergoing modifications which will allow approximately 530,000 cubic meters/ day to be treated to national 4 standard for surface water (suitable for industrial use and other uses not in direct contact with humans) and 470,000 cubic meters/day to be treated to national 3 standard for surface water (suitable for aquaculture and recreation purposes) In the US, mostly all WWTPs’ effluents meet China’s Level II standard for surface water.

Gaobeidian Wastewater Treatment Plant in Beijing processes about 40% of Beijing Municipality’s total wastewater volume and features primary and secondary treatment, methane gas utilization and sludge processing facilities.

In addition to its primary and secondary treatment facilities, Beijing Gaobeidian WWTP also boasts facilities to process and collect the methane gas produced during the anaerobic digestion processes. According to the plant’s materials, a portion of the generated biogas is used internally to make the Gaobeidian’s wastewater treatment processes even more energy efficient (for example as a substitute for natural gas to heat the wastewater digesting processes), and the rest is sold back to Beijing’s energy grid. Some background information about how methane gas generated from wastewater treatment is utilized in the US can be found here.

Built as a demonstrative example for wastewater treatment all over China, Gaobeidian WWTP also has a greenhouse ecosystem on premise that utilizes the Level III standard effluent to as a reclaimed water source. According to reports, after the Beixiaohe WWTP (one of the 15 originally planned WWTP plants for Beijing’s development) was completed in 2007, Beijing reached a reclaimed water usage rate of 50%. As mentioned in a previous post, there are also more and more regulations being passed about the usage of reclaimed water for landscaping and waterscaping purposes in Beijing. As such regulation develops, it is critical that the appropriate advances in wastewater treatment technology are made in order to support such regulation.

Bangalore Lakes in Grave Need of Help!

July 26th, 2010 by

The last stop in my trip to India was Bangalore. Bangalore is the third largest city in India. Bangalore is known as the Silicon Valley of India, due to the rampant IT industry there. It is one of the most prominent cultural and economic hubs in India. Bangalore is truly a beautiful city. However, it is notorious for three things: traffic, frequent power outages, and severe water scarcity.

Let’s talk water – Almost all of the city’s water supply comes from the Cauvery and the Arkavathy Rivers. The Bangalore Water Supply and Sewerage Board (BWSSB) supplies approximately 900 million liters of water daily. However, the demand of water exceeds 1.2 billion liters. Many people once relied on the lakes to suffice their water needs. Most of the lakes of Bangalore are man-made, constructed for the purposes of drinking water, irrigation and fishing. Currently, the lakes in Bangalore suffer heavy amounts of pollution. The Greater Bangalore region once had 400 lakes. Now there are only around 93.

One lake that has suffered greatly from pollution is the Bellandur Lake. The Bellandur Lake is located in East Bangalore and spans an area of 960 acres.  The Lake was once used a main source of water for the people of Bangalore. Water was used for irrigation, fishing, and for household matters, including drinking, washing, and cleaning. Until the 1970s, people in 18 different villages depended on the Bellandur Lake for their everyday needs. The lake has been greatly affected by the rapid urbanization that has been occurring in Bangalore. It has been negatively impacted by domestic and industrial pollution, the destruction of wetlands and the changes in the land usage surrounding the lake. Unplanned urbanization along with unchecked industrial, domestic, and commercial development caused the lake started to suffer greatly.

Currently, a large portion of the lake is covered in weeds and fields. The water in the lake is greatly polluted. There is no aquatic life within the lake. The stench emanating from the lake is beyond foul. At the outlet of the lake, heavy foam from an excess of industrial effluent can be seen.

Heavy foaming in the Bellandur Lake caused by an excess of industrial effluent

The Bellandur Lake is connected to the Agara Lake through a stormwater drain. Bangalore consists of a series of interconnected lakes. The Agara and Madivalla connect to the Bellandur Lake. The outlet of the Bellandur connects to the Varthur.  The lakes are connected by an extensive stormwater drainage system. The system once carried water, however, now it carries sewage. The Bellandur Lake is located in one of the three main valleys of Bangalore, known as the Koramangala and Challagatha Valley. Due to its location, the lake has been used to direct a large portion of Bangalore’s sewage. Currently, the BWSSB has set up three sewage treatment plants with a total capacity of 248 MLD. However, only 110 MLD of the total capacity is actually utilized.  According to the BWSSB, by 2021, the volume of sewage produced by the city will be 359 MLD; by 2036, the volume will be 416 MLD. Already, urbanization and the flux of sewage into the lake have led to eutrophication. An increase in the volume of sewage will only lead to the lake’s further demise.

A major problem exists within the stormwater drains. There is so much pollution within these drains. Untreated domestic waste and industrial effluents are dumped straight into them. The pollution in the drains is directly transferred into the lakes. The pictures below show the pollution accumulating within these drains.

Garbage piling up inside of the stormwater drains

Waste accumulating near an inlet of the stormwater drain

The lakes were once able to serve as natural wetlands, treating the wastewater that flowed into them from the stormwater drains. However, the amount of pollution in these drains exceeds the remediation capabilities of the lakes. The main problem exists in the lack of a strictly enforced waste disposal policy. Punishments should be given to those who are polluting the stormwater drains and the lakes. The citizens of Bangalore should be made aware of the amount of pollution entering the drains and also educated on proper waste disposal techniques, including recycling. Industries polluting the lakes should be fined heavily. Also, the BWSSB should work to increase the capabilities of their treatment plants.

There are various government bodies that are responsible for the Bellandur Lake, including: the Bruhat Bangalore Mahanagara Palike (BBMP), the BWSSB, the Minor Irrigations Department (MID), and the Lake Development Authority (LDA). The lake is located in the jurisdiction of the BBMP. The BBMP is the civic corporation that governs Bangalore. It is responsible for the maintenance of the storm water drains that lead into the lake. The BWSSB is responsible for properly regulating the sewage that enters the lake. The MID has ownership of the lake. The LDA is entrusted with maintaining and preserving the lakes in Bangalore.  These organizations should work together to help preserve the lakes and stormwater drains.

There have been many pleas and enquiries to the government of the Bangalore to help remediate this situation. However, no substantial progress has been made. A strong commitment to restoring the Bellandur Lake and cleaning the stormwater drains must be taken.

All About the Three Gorges Dam

July 20th, 2010 by

Reports of recent flooding in southern China have claimed the torrential rains to be the most severe in scope and damage since 1998. As of July 28th, an estimated 2.9 million people have been relocated, and economic damages have climbed to $3.354 billion. In addition to reports of on the natural catastrophe however, the China Daily, China Post, and Reuters have also observed that the Three Gorges Dam is facing its biggest challenge to date: withstanding and ameliorating the flood waters in the region. Officials are currently expressing concern that a number of dikes in the middle and lower reaches of the Yangze River are susceptible to damage from the accumulating water pressure. Three Gorges Dam engineers have opened three sluice gates to “discharge some 32,000 cubic meters of water per second and another sluice gate to release floating objects.”

Engineers are opening sluice gates of the Three Gorges Dam in response to recent flooding in southern China

The Three Gorges Dam was originally proposed for construction in 1919 by Sun Yatsen as a major source of hydroelectric power on the Yangtze River. Nearly 90 years later, in 2008, the dam was completed, setting world records as the largest electricity-generating plant of any kind. In addition to this massive engineering feat however, has come much controversy. In 2007, the New York Times reported that the project set records not only as the largest power plant in the world, it is also the largest dam, the largest consumer of dirt, stone, concrete and steel ever and has even caused the one history’s largest human resettlement programs. With the official announcement to construct the dam in 1992, came an onslaught of “unusually visible domestic opposition”. Concerns ranged from the fully scientific to the social problems that the construction of such a large structure would create.

Below I have provided a brief summary of some of the concerns people have raised against the dam: (in no particular order)

1. Accumulation of concentrated regional water pollution from surrounding areas

The Three Gorges Dam serves as a giant reservoir that stores water flowing from water basins in southern China, which are infamous for being heavily polluted with municipal and industrial waste, in addition to huge amounts of agricultural fertilizers. In 2001, the People’s Daily reported on the measures being taken to improve waste management strageties by the Central Government in the dam areas and upper reaches of the Yangtze. However, in 2004, the same newspaper released another report stating that many implementations had still not taken effect, including the closing of many small industrial enterprises that grossly surpass wastewater effluent standards, such as the paper and leather industries. The report stated that of 242 large-scale enterprises in the area, 227 also failed to meet standards.

2. Ecological disruption for hundreds of native species

Damming the Yangtze River inevitably causes disruption for the hundreds of species that are native to the area, including the endangered Baiji River Dolphin whose only native habitat is the Yangtze River. Because of the dam, fish species are unable to reach their upstream spawning habitats, affecting their natural biological cycles. Other affected species include the Chinese Sturgeon, Chinese Tiger, Chinese Alligator, Siberian Crane, and the Giant Panda. Chinese law currently protects a total of forty-seven rare or endangered species in the Three Gorges Dam area.

The endangered Baiji Chinese River Dolphin, whose only natural habitat is the Yangtze River, may be affected by the Three Gorges Dam

3. Dislocation of millions of local residents and loss of cultural artifacts

A result of the flooding of 632 square kilometers of land (bringing the total surface area of the dam to 1,045 square kilometers), 1.3 million local residents had to be relocated to other areas. There have been many reports on the psychological, emotional, and economic effects of displaced residents because of the Three Gorges Dam construction. As the water level of the dam rose over 600 feet, entire villages, towns, and even cities were left completely underwater. Although the central government provided allocations for the involuntarily displaced residents, many had trouble in the transition from rural to urban life, many lost their livelihoods with their farmlands, and many suffered from psychological trauma as their ancestral homes of generations were lost. In many cases, fertile farmlands were swallowed up by the rising waters, and reapportioned land distributed to local farmers was by far inferior and difficult to cultivate than the original land. An estimated 1,300 archaeological sites are also reported to have been lost in the flooded area.

4. Silting

The Yangtze River (undammed) carries about 680 million tons of silt to the East China Sea every year, making it one of the most heavily silted rivers in the world. It is estimated that each year 0.5 billion tons of silt will be trapped behind the dam, decreasing the effectiveness of the dam to prevent flood control and increasing the height of riverbeds, and the possibility of secondary pollution from the release of harmful chemicals that may be carried with river silt.

5. Increased landslides and earthquakes

From the increased weight over the flooded area from the dammed water and accumulated silt.

6. The making of an obvious terrorist target

All these negative aspects and concerns over the dam however have not made it a complete failure though. The dam, the largest clean-energy power plant in the world, is a symbol and a realization of China’s commitment to reducing its dependence on coal. A shift from coal reliance will not only benefit China’s environment, it will also improve air quality and reduce acid rain in neighboring Japan and Korea. As China is the world’s largest producer of greenhouse gasses, and is expecting to have even greater energy needs as it continues to develop its economy, “going green” for fuel requirements is perhaps enough to outweigh the negative consequences of the dam.

In addition, the Three Gorges Dam has a positive effect on the navigation of the Yangtze River. Trade along the river has been reported to account for 80 percent of China’s inland shipping. Elevated water levels not only make it possible for larger ships to safely travel up and downstream, the dam also lessens the phenomenon of whirlpools that influence smaller local shipping companies. One local is quoted, saying: “The whirlpools were big back then. If your boat got caught in one, it would spin you around. Now the river’s easy to navigate. Honestly, a 15-year-old kid could steer a boat up it, no problem. There are no big waves anymore.”

The final major point that proponents of the Three Gorges Dam cite is that it will be able to ameliorate the effects of flooding of the area surrounding the Yangtze River. Beginning in the Han Dynasty, records show that in 2,300 years, there have been over 214 major floods in the area, averaging one every ten years. Almost like clockwork, the floods of 2010 are being called the worst since 1998, but now the difference is the presence of the largest dam ever built by man. The Three Gorges Dam has been estimated to be able to protect 15 million people and 1.5 acres of farmland. During flooding seasons, the water in the dam is regulated to a lower level to help receive floodwater from the surrounding areas. During dry season, the dam can also help mitigate the effects of drought upstream. Facing the current flood conditions of southern China, authorities are regulating the water levels in the dam to lessen the impact of the flood downstream.

A view from the Yangtze

Some relevant articles debating the strengths and weaknesses of the Three Gorges Dam include:

  • Burton, Sandra. “Taming the river wild.” Time 19 Dec 1994.
  • “Editorials: ASIA NEEDS DAMS: And yes-there are ways to minimize ecological damage” Asiaweek 15 July 1996.

Open Sewage Systems Hinder Development in Puducherry

July 19th, 2010 by

It’s been two weeks since I have arrived in India. Although I have spent most of my time in Chennai, I have had the opportunity to travel to several other parts of South India. Recently I visited Puducherry (formerly known as Pondicherry), a Union territory of India. Puducherry is one of the most popular tourist destinations in South India. It was under French rule until 1954. The city still retains much of the French influence – the entire layout of the city was planned to imitate French design, mainly in the grid pattern of the city. Colonial ambience of the city is still preserved. Puducherry contains many colonial buildings, temples, churches, historical monuments, and beautiful beaches. Most of the city has been well maintained and remains quite picturesque.

Unfortunately, the beauty of the city was immediately contrasted by the sight and the smell of the open sewage system that exists throughout the city. I was shocked to see that a city with such well developed infrastructure lacked a proper sewage system. The following photos show the open sewage system that runs throughout the city

Open sewer system running through the sides of the streets of Puducherry

Close up of the solid wastes accumulating in the open sewers

In addition to sewage, garbage also accumulates inside of the open systems

An open sewage system raises many environmental and public health issues. Sewage containing human wastes is the most dangerous material polluting the water. The main diseases transmitted through the polluted water are typhoid, paratyphoid, dysentery, and infective hepatitis. Canals containing waste water in Puducherry mix with various bodies of water. In a point where the waste water mixes with sea water, the total coliform count was found to be 475 and the fecal coliform count was found to be 130. This is indicative of fecal contamination creating a high risk of disease. This dire problem can be attributed to the lack of proper waste water treatment.

During the monsoon season or other periods of heavy rain, the sewage system often floods. Currently, flooding is experienced more frequently due to an increase of garbage clogging and overburdening the sewage system. The clogging of the drains creates conditions ideal for disease vectors to breed. During times of flooding, diseases such as malaria, dengue fever, filaria, viral fever, and brain fever are reported. In a place called Solai Nagar in Puducherry all of the sewage is directed into one canal. This canal has not been desilted in years. An excess of waste has clogged the canal, leaving sewage to stagnate in the roadside drains. The drains inevitably overflow during periods of rain. Reports of untreated waste from a nearby hospital polluting the drains have also been filed. Obviously the open sewage system is a pressing issue. Something must be done immediately to expedite the implementation of a proper sewage system within Puducherry.

The Puducherry Pollution Control Committee (PPCC) has devised a scheme to install an underground drainage system and proper waste water treatment facilities in Puducherry. The models are designed to mimic the Japanese solid waste management system. Currently none of the waste in Puducherry is treated, whereas in Japan, 100% of the waste is treated. There is a 70-80% municipal recycling rate in most parts of Japan. Japan has taken a firm stance on minimizing the amount of waste produced in the nation, in addition to maximizing recycling throughout. The current policy in Japan emphasizes an incineration/waste-to-energy plan as a main means of disposing of municipal solid waste. The citizens of Japan are educated on the benefits of recycling and proper waste disposal from a very young age. Almost everyone in the nation is committed to and enthusiastic about keeping Japan clean.

The amount of waste generated annually in Puducherry is projected to increase greatly by 2020. The PPCC has adopted a four pronged plan to most effectively implement the drainage system. The first phase of this plan consists of planning and organizing along with institution building. During this phase, the PPCC wishes to enhance the collection and transport of waste. The next phase consists of the expansion of the service area. In this phase, plans for the control and the protection from pollution of the dump site are included. The third phase consists of introducing the 3-R’s (reduce, reuse, recycle). In addition, social partnerships will be considered and developed. The fourth, and final stage of the PPCC’s plan consists of the total integration of the 3-R’s. In addition, further efforts to educate the citizens on a recycle-oriented and sustainable society, such as the one in Japan, will be made.

Unplanned development of Puducherry has created many environmental problems. These problems have ultimately lowered the standard of living in the city. Amenities that we consider basic, such as clean drinking water, proper drainage facilities for waste, and adequate sewage treatment facilities, are either scarce or non-existent there. There has been a great deal of environmental stress on Puducherry, including increased pollution and the loss of biodiversity. In addition, public health has been risked since there is an improper sewage system. Hopefully the government of Puducherry takes a strong commitment to implementing a closed drainage system. In order for Puducherry to continue to expand and further develop, proper waste treatment must be invested in. It is sad to see such a beautiful city be burdened by the lack of proper sewage infrastructure. Hopefully the Japanese model will serve to help Puducherry reach its full potential as a growing city.

The Hetch Hetchy Debate

July 19th, 2010 by

The proposed Safe, Clean, and Reliable Drinking Water Supply Act of 2010 includes over $2.25 billion in funding for San Joaquin Delta sustainability and repair projects, as well as billions more for statewide water storage projects. To many in Southern California regions like San Diego, the bond measure is fantastic –more funding in the water system means that water-scarce regions will enjoy more abundant (and cheaper) water supply. For many in Northern California regions like San Francisco, the bond measure is less appealing –the bond would make wet cities pay for expensive water projects that benefit dry cities hundreds of miles away. This kind of conflict is inevitable in situations where pooled resources are spent on different groups (or “special interests” in political terms).

Who should pay for whose water? (Image from

A full analysis of the bond and all its pros and cons is beyond the scope of this post, and perhaps such an analysis is impossible because the relationships and dependencies between different groups (i.e. the public and private sector, environmentalists and builders, the northern and southern residents) are often hard to identify objectively. Today, I want to look at a water issue that is closer to home and narrower in scope. Let’s look at the conflict over the Hetch Hetchy Valley reservoir in California’s Yosemite National Park. Studying a smaller water conflict allows us to circumvent the layers of complexity typical in a statewide water conflict and more easily see the details of a water policy debate.

The Hetch Hetchy Valley is a glacial valley in California’s Yosemite National Park. Essentially, it is a big rock bowl. John Muir visited the Hetch Hetchy valley in 1871 and later described the area as one of “Nature’s rarest and most precious mountain temples.” San Francisco would later dam the valley with the O’Shaughnessey Dam, completed in 1923. The once empty rock bowl is now filled with pristine water 300 feet deep.

Hetch Hetchy Valley in Yosemite National Park

The Hetch Hetchy Valley is now filled with pristine water 300 feet deep. (Image from Wikipedia)

From an engineering standpoint, the reservoir created by the O’Shaughnessey Dam is impressive. It is a notable project for the following reasons:

  • The water from the reservoir is conveyed to San Francisco by gravity. The water conveyance system needs no additional energy inputs, unlike the system of pumps that brings San Joaquin Delta water to Southern California.
  • Hydroelectricity generation from the O’Shaughnessey dam provides San Francisco with 20% of its electricity.
  • The water from the O’Shaughnessey dam has “filtration avoidance” status; only minor treatment (addition of lime for corrosion control and chlorine for disinfection) is required before the city pipes the water to end-users.
  • O’Shaughnessey Dam is large. It provides about 25% of the storage in the entire Hetch Hetchy Reservoir system.

From an environmentalist standpoint, the O’Shaughnessey Dam is a blight that has ruined part of Yosemite National Park. Old black-and-white photos of the Hetch Hetchy rock bowl before damming reveal a beautiful landscape. Groups like the Sierra Club and the Environmental Defense Fund support the idea of removing the aging O’Shaughnessey Dam and restoring the Hetch Hetchy to its former glory.

An artist's rendition of the restored Hetch Hetchy valley. (Image from

Removing O’Shaughnessey Dam, however, would require San Francisco to either find new water sources or cut its water use dramatically. Without the reservoir’s pristine water, the city would have to build energy-intensive water treatment plants to bring replacement water to drinkable standards. Furthermore, San Francisco would lose 20% of its electricity supply without generation from the dam.

The Environmental Defense Fund argues that because San Francisco is investing $3.2 billion in overhauling its water system, now is a “once-in-a-lifetime opportunity to reassess the need for the [O’Shaughnessey] dam.” The San Francisco Public Utility Commission considered removal of the dam and concluded that it would cost about $10 billion for its removal and for construction of new water substitutes. Production of additional electricity to treat lesser quality water and replace lost hydropower will have other environmental costs that may outweigh the benefits of restoring the Hetch Hetchy Valley.

The debate over the Hetch Hetchy Valley pits environmental interests against urban interests. Newspapers around the country call for California to restore the valley so that Americans can once again enjoy its natural beauty. Like the larger scale water bond disagreement in California, the disagreement over the Hetch Hetchy involves many views on how natural resources should be utilized in a region.

Should a city spend $10 billion to enhance a national park by restoring an environment to its natural state? Restore Hetch Hetchy, one of the leading organizations in support of removing the O’Shaughnessey Dam, says that water from “Tuolumne river water stored in the Hetch Hetchy valley of Yosemite National Park can be stored elsewhere and delivered without interruption to its end users.” Where, exactly, is elsewhere? While Hetch Hetchy may be restored, another area’s ecological system may be utilized in its stead. San Francisco needs to get its water from somewhere, after all.

Everything that city and state governments do affects groups differently. In California, investment in the San Joaquin Delta system benefits farmers in the central valley and residents in Los Angeles, but it threatens some endangered fish species and forces Northern Californians to pay for Southern Californians’ massive delta withdrawals. Also, there are environmental groups on both sides of the debate; the Nature Conservancy and Audubon Society support the bond while the Sierra Club and the Planning and Conservation League oppose it. The complexity of the California water bond debate is shaped by numerous individual examples such as the Hetch Hetchy conflict. Even the smaller, regional Hetch Hetchy conflict involves huge differences in geographic, hydrological, social, and special interests.

I doubt the O’Shaughnessey Dam will be removed any time soon, but groups will continue to lobby for the restoration of Hetch Hetchy Valley. Meanwhile at the macro-level, the state continues to struggle with the water bond debate. Unless the bond is delayed until the 2012 ballot, voters will have to pick a side by November this year.

Lecture at Stanford’s Center for Sustainable Development

July 15th, 2010 by

Bry Sarte, Executive Director at the Sherwood Institute, delivered a lecture yesterday at a special forum hosted by Stanford University’s Center for Sustainable Development and Global Competitiveness. In his talk, “Regenerative Urbanism: City-Scale Sustainable Water and Energy Strategies in China,” Bry discussed the Institute’s work in the Chinese city of Langfang to create and implement new policies in the area. The Sherwood Institute is working to create a comprehensive policy package for the city. The package will address urban water issues regarding stormwater, wastewater, rainwater harvesting, and general green design principles in water management. You can learn more about Langfang in this recent post on the Sherwood Engineers blog.

Stanford’s Center for Sustainable Development and Global Competitivenessbelieves that all future economic and business developments should be based upon environmental concern. They are working to fulfill this mission by promoting and teaching business strategies and leadership practices that will promote a sustainable and green environment.

The forum brought together speakers, academics, professionals and students to discuss opportunities and challenges in providing services in the environmental services sector in China.

Rainwater harvesting helps Chennai meet water demands… What about stormwater?

July 4th, 2010 by

Hello all, I am currently writing from Chennai, India, in a town called Ayanavaram. Chennai has suffered chronic water shortage problems for many years. Under the administration of former Chief Minister of Chennai, Dr. J. Jayalalithaa (served from 1991 – 1996 and 2001 – 2006), an intensive rainwater harvesting scheme was developed in order to reduce water demands and increase supply. The Chennai Corporation, the civic body that governs Chennai, has adopted rainwater harvesting methods in order to raise the ground water level, prevent water stagnation, and divert water from being wasted. The Chennai Corporation started installing rainwater harvesting systems from 2001 in all Corporation owned buildings, including schools, hospitals, office buildings, community centers, bridges, parks, etc. In total, the Chennai Corporation installed 1,344 catchment structures in government owned buildings. Currently, building plans are only sanctioned if provisions are made for rainwater harvesting. After the implementation of such widespread rainwater harvesting systems, many of the water problems in Chennai have been solved.

Within the past couple of days, heavy rains have hit Chennai. Luckily, because of the great progress the government of Chennai made to alleviate the water crisis, rainwater catchment systems have been installed in the majority of urban areas. In fact, rainwater catchment systems have been installed in almost 350,000 residential, commercial, and institutional buildings. The apartment building where I am staying has a rainwater catchment system. Several pipes are attached to the roof that transport rainwater from the roof to an underground storage unit. The pictures below show how rainwater is harvested.

The monsoon season commences in South India in June. Within just half an hour of rainfall, the crowded streets became flooded. The picture below shows a street near where I am residing. As you can see, in such a short amount of time, nearly three inches of rain already collected on the surface.

Heavy rains cause immediate flooding in streets. Location: New Road, Ayanavaram, Chennai, India

Unfortunately, although there has been a great deal of investment in rainwater harvesting, there has not been that same commitment to utilizing stormwater and surface runoff. The Chennai Corporation has developed a storm water drainage system, however, it appears that much of the surface runoff remains stagnant until the water evaporates. The flat terrain of Chennai requires an effective stormwater drainage system in order to prevent water stagnation, which can facilitate the spread of diseases such as malaria. Just recently, construction has begun on a 21.4 km stormwater drainage system, on the Royapuram watershed, that will benefit nearly ten large areas. This project has been funded by the Jawaharlal Nehru National Urban Renewal Mission (JNNURM). Under the JNNURM, 12 additional projects are under development in Chennai.

In today’s world, resources are limited. One of the most precious resources, that many of us take for granted, is water. The work done by the Chennai Corporation is extremely commendable. The rainwater harvesting initiatives have helped a good proportion of the 4.2 million people that live in Chennai gain access to clean water. However, many still do not have access to clean water. Further development must be made to expand and improve rainwater harvesting systems. In addition, a comprehensive plan must be devised to minimize the waste of stormwater and the amount of water runoff. Investment should be made in a greater stormwater drainage system. Chennai has already seen a great deal of improvement in meeting its water demands; hopefully with continued government support and public awareness, the entire population of Chennai will have access to clean water.

Call for topics!

July 1st, 2010 by

So far, we’ve covered a variety of topics relating to water issues in China. If any of our readers have topic suggestions– anything you’d like to know more about regarding China, water, environment, policy, etc. Please leave a comment. I will do my best to address your interests!


Rainwater Utilization in China—History and Current Issues

June 30th, 2010 by

A Google search on rainwater utilization in Beijing mostly yields articles about the rainwater collection and purification systems that were built into Olympic venues the Bird’s Nes and the Water Cube.  Indeed, such facilities demonstrated China’s increasing realization of its water scarcity issues and its recognition of a huge and largely unused resource: rainwater. However, what has been largely unseen in the English media is the development of the overall picture of rainwater utilization in China. What is the current state of the art? What has the history of the practice of rainwater utilization in China been up to now and what is its potential for the future?

Not only is China a water scarce country, water scarcity may be a significant factor in limiting the country’s development in the future. According to a 2009 report, of China’s 669 cities, 400 do not have enough water to meet distribution demands. In Beijing, the amount of water availablity per capita is less than 300 cubic meters, which is about one-thirtieth of the global amount. In many areas, especially in northern China (including Beijing), groundwater is overextracted in order to meet water demands, causing permanent ground subsidence damages. In order to reroute more abundant resources from the south to northern China, other large scale water diversion projects have been planned, but not without controversy . There have also been more and more demand-side campaigns to encourage residents, developers and industry to reduce water usage. In the eyes of some researchers and policy-makers however, one very obvious source of water has not been utilized to its full capacity: rainwater.

Raining outside the Olympic venue the "Water Cube", which is designed to collect enough water annually to supply 100 Beijing residents

According to rough calculations, if Beijing municipality covers an area of 770 hectares and the annual rainfall is 630 mm, then the amount of rainwater the city receives each year is about 485 million cubic meters of water. If Tianjin covers an area of 640 hectares, and its annual rainfall is 600 mm, then it receives 276 million cubic meters of water each year. Similar calculations yield that Jinan, Shandong Province would receive about 80 million cubic meters of rainwater annually. If a significant portion of this largely unused resource could be collected, we can see that its impact on water scarcity in northern Chinese cities could be a very important resource.

There are two types of utilization methods for rainwater. One is to actively create sites where permeable facilities replace impermeable pavements (for examples, large parking lots or public squares), so that rainwater can slowly infiltrate into the underlying aquifers, recharging the water levels. The other kind is what we think of as active rainwater harvesting. These facilities may be located on rooftops or built into buildings. The water is collected and stored and or treated for landscaping, waterscaping, toilet flushing, or industrial cooling or rinsing usages. To a certain extent, both active and passive rainwater harvesting techniques have been implemented in China.

Rainwater utilization first began to be explored as a resource possibility in the 1980’s. At that time, certain local governments began to notice their water scarcity problems and installed rainwater collection systems on buildings. However, because at that time such facilities did not have the necessary accompanying treatment or reuse systems, their effect was not practical. In the 1990’s, the Beijing Water Conservancy Office (Now the Beijing Municipal Water Conservancy Bureau ) headed up two rainwater research projects—“Research on Beijing Municipality Urban Rainwater Utilization Technologies and Rainwater Infiltration Expansion” and “Beijing Municipality Urban Buildings’ Increased Water Collection Measures Research”. These two research projects reflected the two branches of rainwater utilization and the results of the research helped propel advances in the efficiency lacking in previous attempts at rainwater utilization. The research included not only technological research, but economic, urban planning and policy analysis. By 1998, with funding from the Beijing Municipal Government, over 20 rainwater utilization projects were completed.

In the year 2000, The Beijing Water Conservancy Bureau launched a joint project with Essen University (Germany) to build 6 demonstrative projects under the title “Urban Rain Flood Control and Utilization”. The projects were carried out in several distinct representative areas, converting paved areas into more porous surfaces (for groundwater infiltration) and installing catchment facilities to collect water (for car washing, toilet flushing and landscape use). The results of the project indicated that although the rainwater could be successfully reused for other purposes, when the economic factors of installing active facilities (as opposed to the passive infiltration facilities) were taken into accout, the outcomes were not very practical. Because Beijing receives little rainfall for about half of the year, the active facilities laid unused for too much time for such a plan to be considered for widespread use. Also in the year 2000, for the first time, the Beijing Municipal government passed a law stipulating that in residential communities, water for fountains and waterscapes must be supplied with either reclaimed water or with rainwater to decrease the strain on the potable water supply.

Waterscapes in residential areas in Beijing are required by law to utilize reclaimed water or rainwater instead of tap.

In 2001, China’s State Council passed a document called “The Beginning of the 21st Century Capital Water Resources Sustainable Utilization Plan” (21世纪初期首都水资源可持续利用规划), which states that in Beijing, rain water utilization should be an important measure to reduce the severity of water scarcity problems in the city. In 2003, The Beijing Municipality Planning Bureau and the Beijing Water Authority jointly passed an interim provision that all new construction, renovation, or expansion projects must go through rainwater engineering facilities design and construction. In 2004, the Standing Committee of the Beijing People’s Congress passed a law encouraging individuals and work units to utilize rain harvesting, infiltration, storage, and utilization strategies. In 2005, the fine for residential communities utilizing tap water for landscaping or waterscaping purposes was raised over 10 fold, showing the municipal government’s commitment to reclaimed wastewater and rainwater usage. Also in 2005, the Chinese Architectural Design Research Institute (中国建筑设计研究院) made a number of standardizations to rainwater utilization techniques.

Most recently, for the 2008 Olympics, the Water Cube and the Bird’s Nest were all equipped with the most modern rain harvesting and treatment technologies. The Bird’s Nest rain harvesting area is 22 hectares, and it is able to collect 67,000 cubic meters of water annually and treat 2000 cubic meters of water daily. The Water Cube has a rooftop rain harvesting system that collects 10,500 cubic meters of water annually and it can treat enough water to support 100 Beijing residents’ water usage for one year.

An article published in Chinese in 2009 purports 5 major reasons that China still lags behind developed countries in its extent of rainwater utilization. Firstly, the technology lags behind developed countries. Secondly, rainwater utilization facilities are not adopted on a large scale. Thirdly, relatively little legislation exists for the appropriate treatment of rainwater (for example, urban runoff may enter the same channels as municipal wastewater and be treated as such in the urban water cycle). Fourthly, there is little standardization of rainwater harvesting or infiltration techniques. Lastly, the “level of industrialization” around issues of rainwater usage is low.

“Level of industrialization” refers to the development of corporations that work in services and technologies relating to rainwater utilization. Such corporations include those that provide collection and treatment services for rainwater, those that are able to market and sell filtered or treated rainwater effluent, corporations that provide technology support, maintenance and repair services, and corporations that actually sell equipment and technology for rainwater utilization designs.

However, the future looks bright for increased rates of rainwater usage in China. In an article by the Worldwatch Institute, experts have already seen trends in rainwater utilization systems design by real estate developers in Beijing, probably in response to recent legislature that requires residential areas to used reclaimed water or rainwater for waterscapes. Currently, many rainwater consulting projects are done by academic institutions such as universities, institutes or national academies. In the future as legislations become more defined and implemented on a national scale, there will probably be more room for development for private environmental consulting agencies who wish to enter the market.

The information in this article is a summary of information gathered from the following sources:

李俊奇,邝诺,刘洋,何建平.北京城市雨水利用政策剖析与启示 (Analysis and Inspiration of Rainwater Utilization Policies in Beijing). China Water and Wastewater. 2008

胡继连,葛颜祥,李春芳.城市雨水资源化利用政策研究 (Urban Rainwater Utilization Policy Research). Shandong Social Sciences. 2009

State of Water: Comparing California and Japan

June 28th, 2010 by

As a California resident, I am bombarded by drought alerts and pressure to conserve water. The California Department of Water Resources is warning us that 2010 could mark the 4th consecutive year of drought. Even though the state suffers from a $20 billion budget deficit and carries over $70 billion in outstanding bond debt, the senate has put an $11.14 billion water bond measure on the November ballot –there is a strong sense of urgency in the state regarding our future water supplies.

While planning my summer vacation in Japan I asked myself a question: Does Japan suffer from domestic water shortages like California does, and why? It seems proper to compare California and Japan. Both have huge economies: California’s economy is the eighth largest in the world while Japan’s is the third largest in the world. The majority of Californians and Japanese rely on public water sources for domestic supply.

The two places are vastly different in ways that make comparison interesting. While both entities occupy nearly the same land area (California: 403,932 km2, Japan: 394,743 km2), Japan’s population is over three times the size of California’s (California: 38.3 million, Japan: 128 million). The Tokyo prefecture alone touts a population of nearly 39 million while occupying an area equivalent to 10% of California’s area.

City Density Comparison

San Francisco, California’s densest city, is not nearly as dense as Kyoto, Japan’s densest city. Both pictures show an equally magnified square kilometer around city hall. Density data:

California has water supply problems primarily because 75% of its water originates in the top third of the state while 80% of demand is in the southern two thirds of the state. To sustain large populations in southern California, the state and federal government constructed dams and canals to boost water storage and transport. California has a storage capacity of nearly 50 billion cubic meters spread over 1000 dams. Japan is abundant in water resources; the country consistently receives one to two meters of rainfall each year. The country’s abundance of water has made it easy for people to obtain water without massive dams and canals. Japan sports a distributed network of over 2500 dams that have a total storage capacity of about 20 billion cubic meters –less than half the capacity of California’s dams.

Demand for water in Japan is also far lower than in California. California’s domestic water use is about 470 liters per capita per day (2005 USGS data). Japan’s domestic water use is one-third less at 314 liters per capita per day (2008 data). Why is the demand so different? One explanation is that city dwellers in Japan rarely need water for outdoor irrigation. Drive through the streets of a Southern California suburb and you will see lot after lot of lush front lawns (don’t forget the back lawn too!), flower gardens, and trees. The California Homebuilding Foundation estimates that over 50% of water demand in California homes goes towards outdoor landscaping. Outdoor use is less in Japan where population densities are often several times higher than even the densest California cities –there is no room for a lawn.

Created by the Sherwood Institute

Japan devotes nearly twice the fraction of its water to industrial purposes as California does. Meanwhile, California invests more water into agriculture.

Note: Japan might suffer from water shortages if it were forced to produce its food and other water-intensive materials domestically. Currently Japan is less than 45% food self-sufficient so it indirectly consumes the water used to produce grains, oils, and meats its people import. Japan is also one of the world’s top textile importers. Global water shortages would affect food and textile production which would in turn affect Japan’s ability to feed and clothe itself. Not even the water-abundant Japan can escape the effects of global water shortages.

The Public Policy Institute of California estimates that California’s population will grow to 46.7 million by 2025. Current water supplies can barely satisfy the demands of today’s 38 million residents. A 23% increase in population will further stress the water situation in the state.

Meanwhile, Japan is predicted to experience a population decrease of 20 million people over the next 50 years. The country does not expect to have water shortages in the near future: Japan’s growth is not limited by its water supply.

Water supply currently limits growth in California. A cap on growth is not inherently bad, though. One can argue that investing billions in expanding water supplies will enable new growth, but further growth will encourage further billions to be invested in expanding water supplies. This creates a positive feedback loop that is difficult to escape: Growth fuels demand, new supply fuels growth. The nearly bankrupt state cannot sustain this cycle forever.

Like Japan, California’s population will peak. Unlike Japan, this peak will most likely be a result of water shortages. Japan is able to sustain a large population because its water resource is abundant and because its per capita demand for water is relatively low. California’s water supply is scarce and its demand high.

How do you think California can solve its water needs in the long term? What do you think about the new water bond on the November ballot? Feel free to comment.

2010 WEF Wastewater Challenge + Conference

June 15th, 2010 by


Yesterday was the first day of the 2010 Water Environment Federation (WEF) Collections Systems Conference. This year the conference takes place at the Phoenix Convention Center in Arizona.

Water professionals from around the country will gather here in the next few days to discuss water issues regarding rainwater harvesting, stormwater management, and wastewater treatment. Companies will also show off their water-related products (pumps, flow meters, and more!) in the exhibitor’s area. The conference promises to be an intellectual stimulating event packed with water workshops and lectures.

But I didn’t go for the conference –I went for the WEF Wastewater Challenge, a water treatment competition open to colleges around the country.  This year is the pilot year for this national competition.

I am part of the UC Berkeley Environmental Team.  Our system utilized two sand layers and a canister full of activated carbon and charcoal to treat water. Our system treated water with physical processes (filtration, adsorption, etc.); other schools added chemicals like bleach and hydrogen peroxide to adjust color and pH of the water.





Most of the teams that attended were from colleges in the Western United States, but one team flew in from as far as Ohio. Eight schools competed this year: Cal Poly Pomona, Cal Poly San Luis Obispo, Colorado State, Ohio State, UC Berkeley, UC Irvine, University of Wisconsin, and Washington State.

Teams must design and build a portable wastewater treatment system to treat 10 gallons of simulated wastewater. Points are awarded for simplicity of design, innovation, treated water quality. Teams also submit a design paper and deliver a 10-minute presentation about their systems.

After hours of water treatment and team presentations, judges reviewed their scorings and announced the winners… Here is the top three:

1st Place: UC Irvine

2nd Place: Cal Poly San Luis Obispo

3rd Place: UC Berkeley

Go Bears!

Containing the Oil Spill

June 12th, 2010 by

BP has discontinued their calculations on the amount of oil exiting the well; they have handed this responsibility to the US government. Just yesterday, this taskforce announced that approximately 25,000 to 30,000 barrels of oil are flowing into the Gulf per day. On May 27, BP had estimated that anywhere between 12,000 and 19,000 barrels of oil were exiting the well per day. A month before that, the estimate was 5,000 barrels per day. The first estimate, given several days after the start of the spill, was a “mere” 1,000 barrels per day. 50 days after the oil spill, one could only hope that this number would start to decrease… not increase…

By studying the estimates given by BP, you will see that an almost perfectly (positive) linear relationship exists between the time that has elapsed and the magnitude of the flowrate. In fact, a 95% correlation exists.*

Last week, a containment cap was placed on the well to control the amount of oil exiting into the Gulf. The cap can capture 11,000 barrels per day. However, a large amount of oil is still escaping. The containment cap was designed to funnel the oil to a ship on the surface. Another containment system, which uses the pipes of a previously failed attempt to control the leak, directs more oil to an extra vessel. An additional method is supposed to be installed by the end of this month. This method is expected to withstand hurricane conditions.

The containment cap was lowered onto the failed blowout prevented (BOP) valve system on the seabed. The cap was placed on the lower marine riser package (LMRP) section of the BOP. On June 1, the damaged pipe which removes oil from the well, known as the riser, was cut near where it reaches the seabed. Undersea robots were used to cut through the riser close to the LMRP. After the riser was removed, the cap was lowered onto the LMRP, enabling the leaking oil to be funneled to the ship on the surface.

Schematic of the containment cap on the LMRP

It is difficult to determine whether the cap is effectively working, mainly due to the lack of consensus regarding the magnitude of the spill. Currently, the total volume of oil that has escaped the well has been estimated to be anywhere between 20 million to 45 million gallons. The flowrate of oil leaving the well has fluctuated greatly and rapidly evolved – from an initial estimate of 1,000 barrels/day to a present estimate of 27,500 barrels/day.

Officials warned BP that cutting the riser may worsen the leak by 20%. Ira Leifer, an expert part of the government taskforce to determine the flowrate, believes that installing the containment cap has made the leak worse. Leifer claimed that the pipe is fluxing more than it previously did. BP has not made any claims as to whether the leak has worsened – they have merely claimed that their engineers are working to make the containment cap as efficient as possible.

Let’s say that cutting the riser did worsen the leak by 20%. The latest estimate by BP (approximately 27, 500 barrels/day) was released after the riser was cut. So according to officials, the exit rate of oil would have been approximately 4,580 barrels/day less, if the riser was not removed. However, the containment cap is projected to capture 11,000 barrels/day. Thus, the additional oil spewing out of the well from installing the containment cap is an additional sacrifice the Gulf of Mexico has to take.

However, we do not know if cutting the riser actually worsened the leak – just like the exit flowrate, there is no consensus on this matter either. BP has not made any statements on the efficacy of the cap. Some officials, including Leifer, believe that the cap worsened the spill by significantly more than 20%. The one thing that is certain about this oil spill is the amount of uncertainty it has produced. Oh, and of course, the amount of damage that it has caused, and will continue to cause.

Oil Pools near Barataria Bay on the Louisiana Coast

A permanent solution to the leak must be discovered soon. BP is digging two relief wells by the end of August. BP hopes that these wells will provide a permanent solution to the oil spill; again, it is uncertain whether they will be truly successful.

The spill has killed 11 humans; many birds and marine animals have either been severely injured or killed. A third of the federal waters of the Gulf remain closed to fishing. Admiral Thad W. Allen of the Coast Guard described the oil spill as “an insidious enemy that’s attacking our shores.” The oil spill has been called the nation’s worst environmental disaster. President Obama has claimed that if Tony Hayward, the chief executive of BP, worked for him, Hayward would have been fired for his poor handling of the oil spill.

* Calculated by plotting the estimated flowrate versus the number of days elapsed since the spill started. The estimates released on May 27th and June 10th were given as ranges. For the purpose of obtaining a correlation, the values were averaged to obtain an approximate flowrate of 15,500 barrels/day and 27,500 barrels/day respectively.

A Closer Look at Water Rights

June 9th, 2010 by

Do you own the water coming out of your tap? In Nevada, the Southern Nevada Water Authority opposes gray water reuse and requires users to return used water through the normal treatment pathways. In other words, the Southern Nevada homeowner pays to borrow the water –not to own it.

Whether you own your tap water or not depends on the supplier you receive it from (i.e. public vs. private suppliers). A more interesting question is: Who owns the rain?

Who owns the rain? (Image from

Rainwater harvesting allows people to capture and store the rain that falls on their property. By keeping a stock of rainwater around, landowners reduce demand on the public tap and spare potable water from use in non-essential applications.

You may think you own the rain that falls on your property, but in many cases the water actually belongs to someone else with a “senior water right” in your state. “Prior appropriation,” also known as the Colorado Doctrine, appropriates quantities of limited water resources to whoever laid claim to them first.

Most states west of the Mississippi have adopted the prior appropriation system to deal with water allocation (eight states operate exclusively on prior appropriation, the rest use a blend with riparian water rights). Landowners who possess senior water rights granted by the State are given priority access to water before everyone else. Junior water rights holders are allowed access to the same water resources so long as their use does not prevent senior rights holders from getting their share.

Since rainwater may eventually become part of streams, lakes, and groundwater, some states have forbidden rainwater harvesting because the act intercepts water before it can reach those with senior water rights. Until recently, you could face criminal charges for collecting rainwater in Colorado or Utah.

A rainwater harvesting system like this one would have been illegal in Colorado and Utah a year ago. (Image from

Policies are changing. Until June 2009 it was illegal to collect rainwater in Colorado without a water right. Today, Colorado residents can install rain collectors after obtaining a permit from the Colorado Division of Water Resources. In October, the Washington Department of Ecology clarified that homeowners do not need to obtain water rights to harvest rain, but it also stated that it would review rainwater harvesting’s impact on existing water rights to make a more absolute judgment.  Utah followed suit in may this year, making it legal to collect up to 2500 gallons in rain barrels but requiring users to register rain barrels with the Utah Division of Water Resources.

While it is now legal to collect rainwater in Colorado and Utah, the fact that you need a permit to do so suggests that the rain hitting your roof still does not belong to you.

Is it legitimate to promise senior rights holders water that hasn’t yet reached their claimed rivers and streams? Or is this extension of prior appropriation on to private property a breach on others’ property rights?  Who has the right to own water? Or should we view water as a shared resource that lies outside the realm of private ownership?

People often advocate graywater reuse or rainwater harvesting without considering the deeper political debate behind water resources. Depending on how you view water and property rights, for instance, rainwater harvesting can be interpreted as theft or it can be interpreted as use of your own naturally supplied water.

We welcome your opinions about water rights. Feel free to comment on this post and let us know what you think!

Sometimes the water rights conflict becomes a state affair. Here are a few historic state battles over prior appropriation:

Wyoming v. Colorado: Wyoming, having claimed rights to the Laramie River before the State of Colorado, sued to prevent Colorado from diverting flow away from Wyoming. The court ruled in favor of Wyoming but granted Colorado a small share of the water in the system.

Arizona v. California: Water from the Colorado River is allocated to states by prior appropriation. Arizona and California have a long history of water conflict around the Colorado. In 1934, Arizona governor Benjamin Moeur sent troops from the state’s National Guard to stop construction of the Parker Dam on the border of Arizona and California. The dam would route part of the Colorado River flow away from Arizona and into Los Angeles.

Calling all the dispersants!

June 2nd, 2010 by

Corexit still being used in the Gulf of Mexico Oil Spill

The Environmental Protection Agency (EPA) has warned BP to discontinue the use of the dispersant Corexit. Corexit is manufactured by Nalco Co., a company which BP has “diplomatic relations” with. A dispersant is a chemical solution used to disintegrate oil into smaller and finer droplets. These microscopic droplets then sink into the water. Before the EPA’s recommendations, BP had already used 700,000 gallons on the surface and 115, 000 gallons underwater.

Overhead view of Gulf of Mexico oil spill

The EPA gave BP 18 alternative, less-toxic, dispersants to use on the oil spill. Some of these dispersants have been shown to be twice as effective.  According to the EPA, Corexit is significantly more toxic than some of its competitors. It has also been found to be significantly less effective. In a test to determine effectiveness, the EPA found that 12 out of the 18 recommended dispersants were more effective on Louisiana crude oil than Corexit. Two of the 12 were found to be 100% effective. Corexit was found to be only approximately 59.5% effective.

BP has declined considering and testing other dispersants. Corexit has been called “a chemical that the oil industry makes to sell to itself,” by Richard Charter, the senior policy advisor for the organization, Defenders of Wildlife. Corexit was also employed in the clean-up of the Exxon Valdez spill in Alaska’s Prince William Sound in 1989. Clean-up workers have suffered many health problems after, including a variety of kidney and liver disorders. These health problems have been attributed to the chemical 2-butoxyethanol, a known human carcinogen, found in Corexit.

Questions also arise on the effectiveness of using a dispersant at all for this oil spill. Dispersants are generally used to remove oil off the surface of water and to protect large quantities from reaching the shore. However, the source of the oil spill is located one mile underwater and 50 miles offshore. Due to the desperation of the situation, BP is forced to utilize such a large amount of dispersant.

An alternative to using dispersants is utilizing bioremediation to clean up the oil spill.  In bioremediation, microbes are used to degrade the oil. The microbes work by breaking down hydrocarbons found in oil in the presence of oxygen and other nutrients. The microbes can degrade oil more efficiently if the oil was already broken down into smaller droplets. Corexit has already been applied to break down the mass amounts of oil. Now may be an optimal time to explore use of  microbes. After the oil droplets sink beneath the surface, naturally occurring microbes break down the oil. Bioremediation can serve to complement naturally occurring oil degradation.

Toxicology expert, Dr. William Sawyer, has deemed Corexit as “deodorized kerosene.” He continued by saying that studies on kerosene exposure “strongly indicate potential health risks to volunteers, workers, sea turtles, dolphins, breathing reptiles and all species which need to surface for air exchanges, as well as birds and all other mammals.” BP has already accumulated a third of the world’s available dispersant supply.  This has been the largest use of a chemical used to clean up an oil spill within the US. Hopefully the damage already done by Corexit is not as grave as predicted by the EPA and other officials.

Deepwater Horizon: Climate Change Impacts

May 26th, 2010 by

Last Thursday marked the one-month anniversary of the Beyond Petroleum (BP) Deepwater Horizon oil rig disaster in the Gulf of Mexico just 40 miles off the Louisiana coast. A pipe rupture 5,000 feet below the ocean surface is spewing out crude oil and natural gas at an unknown rate. The scientific community has produced spill rate estimates that range from 5,000 to 100,000 barrels of oil per day. BP, after repeatedly denying the importance of obtaining an accurate rate estimate, has finally agreed to post a live video feed of the leak to help third parties create estimates.

Firefighting boats attempt to extinguish the burning Deepwater Horizon oil rig. The rig sank after burning for 36 hours. (Associated Press photo, Photographer: Gerald Herbert)

The indirect environmental cost of a disaster like BP’s spill is hard to quantify. State governments are quick to estimate economic losses from affected fishing and tourism, but what about the disaster’s immediate effect on climate change? In this post we will offer a few calculations to demonstrate the magnitude of the spill’s environmental impact.

We must first quantify the severity of the spill. Unfortunately, BP has only provided approximations of the spill rate and has refused to allow outside involvement in undersea measurements. We can only estimate the spill based on scattered information released by BP, main news streams, government agencies, and scientists.
The Official Word:
  • Last Thursday BP reported oil capture (via an interception tube) at a rate of 5,000 barrels per day, but soon afterwards revised the amount to 2,200 barrels per day.
  • BP estimates that half of the volume spilling out of the deepwater rupture is comprised of natural gas. BP’s interception tube was able to capture 15 million cubic feet of natural gas in a 24-hour period last week in addition to its reported capture of 2,200 barrels of oil.
Outside Estimates:
  • A federal task force dubbed the “ Flow Rate Technical Team” will try to produce a scientifically credible estimate of the spill rate this week once it has had time to model the spill.
  • Steven Wereley, associate professor of mechanical engineering at Purdue University, modeled the leak based on a video from BP. Last Wednesday, Wereley told the House Energy Committee that about 70,000 barrels were spewing out of the rig rupture each day (± 20%).

Most experts agree that the Deepwater Horizon spill is more severe than the Exxon Valdez tanker spill of 1989. Exxon Valdez spilled 10.8 million gallons over the surface of the ocean off the Alaskan coast. At the lower end of Wereley’s estimate, the Deepwater Horizon rig could be spilling 56,000 barrels (by volume) per day into deep ocean currents.

After subtracting a conservative 5000 intercepted barrels per day (BP’s highest reported capture rate) and assuming 50% of the spill volume is methane gas, the spill could release about 25,500 barrels of crude to the environment per day. At this rate it would take just over 10 days for the rig to spill the same volume released by the Exxon Valdez. Thirty-six days have passed since the spill first erupted.

Natural gas, an odorless and invisible gas, is difficult to intercept once released to the environment. At 5000 feet deep, the ocean pressure is about 140-150 times the air pressure at sea level. If half of the leaked volume is indeed natural gas as BP claims it is, we can calculate that 25,500 barrels of gas is released per day. At deep ocean pressure and temperature (145 atmospheres and an assumed 0 °C), this amounts to about 280 tonnes of natural gas released to the environment each day.* Natural gas has about 20 times the global warming potential of CO2 over a 100-year span.

The amount of CO2 equivalent to the natural gas leak (280 tonnes * 20 = 5600 tonnes CO2 per day) is emitted daily by 390,000 average American cars (MPG = 20.4, traveling 11720 miles per year). It would take over 140,000 tree seedlings grown for 10 years to sequester the carbon in 5600 tonnes of CO2. All equivalencies were calculated with US EPA equivalency calculator.

Today, BP engineers are preparing a “top-kill” procedure to plug up the leak. If top-kill is successful, the leak could stop as early as this week.  Such a procedure is commonly performed to stop sub-surface oil leaks, but never at depths as great as the Deepwater Horizon rupture. We can only guess when BP will successfully stop the leak. A worst-case scenario offered by BP chief operating officer Doug Suttles projects leak stoppage in August of this year.

*This is calculated using the ideal gas law and a molecular weight of 16 grams per mole (methane), assuming that all natural gas is in gaseous form. At high pressures and low temperatures the ideal gas law becomes less reliable, but the equation errs in the conservative direction. Real gas law calculations with van der Waal’s constants for methane yield a mass flow rate about 50% higher than the 280 tonnes per day calculated with the ideal gas law.

Note: The back-of-the-envelope calculations in this article are based on estimates provided by BP and Professor Wereley of Purdue University. These quick calculations help us appreciate the scale of the disaster, but they are not offered as facts. If you have better calculations or find errors in ours, we welcome you to comment!


Mountian-Water Cities: Chinese “Eco-Cities”?

May 22nd, 2010 by

With the opening of the 2010 Shanghai World Expo perhaps some have noticed that amongst the many reports of the expo’s environmentally friendly facitlities and regulations and many environmental exhibits, one highlight has recently disappeared from the expo’s website and official publicity. The Dongtan Eco-city, originally widely publicized to international media as the “world’s first large-scale eco-city” and which was scheduled to complete construction before the expo, has disappointed many and caused some skepticism about the possibility of truly building “eco-cities” in China. Christina Larson, on Environment360 reports that a possible reason for the failure of eco-cities such as Dongtan in China is a misconnect between the (often internationally-designed) master plans and the actual fruition of the cities by developers and government. reported that Wired and BBC both allude to misunderstandings between the expectations of the Dongtan clients and the planning team.

However, despite the disappointments voiced in the international media about the failure of the realization of some Chinese “eco-cities”, there is also a new Chinese buzzword slowly gaining more popularity in both popular media and in architectural and urban planning circles: “Mountain-Water Cities” (山水城市) . According to Baidu Encyclopedia, the term “Mountain-Water City” was first coined in 1990 by Dr Xuesen Qian, a former professor at both Caltech and MIT, and highly recognized scholar and party member in China. Interestingly, he is most famous for his contributions to the missile and space programs in both the United States and China.

At a conference given last month in Beijing on Mountain-Water Cities (April 18, 2010), Qian described Mountain-Water Cities in the following way:

“There are mountains and water. We depend on rock and are accompanied by water. Both of these balancing elements should be clearly visible. The city should have an appropriate amount of forested area and green spaces, the right amount of rivers, streams and lakes, and enough natural ecology. The goal is to allow a city to possess a positive natural environment, life environment, and residential environment.”

From this description, the traditional balances of the Chinese conception of nature—water and mountain/rock—are present alongside and interwoven with human life. Qian stated that traditional forested parks are just one part of the concept of “Water and Mountain” (see my post on Water in Traditional Chinese culture”. “Water and Mountain” really stands for a much higher ideal: that man should find unity with nature, a principle first understood by classical Chinese poets and painters and deeply rooted in Chinese culture. “We should think of it like moving the beautiful landscape of those paintings right into our city” he said.

The Mountain-Water City Conceptual YinYang. Black: Humans, White: Nature, Gray: The Mountain-Water City. Source:

Dr. Hu Jie's conceptual model for Mountain-Water City design. The large circle is nature; the three smaller circles are mountains, water, and cities; humans are in the middle. Source:

In addition to the presence of nature in a city, Qian emphasizes the importance of people’s livelihoods and of traditional Chinese architecture and lifestyle supported by scientific advancement. In a mountain-water city, social services and amenities should be accessible, and the unique characteristics of Chinese cities—courtyards, city gates, etc—should be integrated into a sustainable urban environment.

Though Dr. Qian is accredited to having first used the term “mountain-water city”, in recent years, the terms has been attributed to Dr. Hu Jie, the principal designer of the Olympic Forest Park in Beijing. After designing Olympic Forest Park, Dr Hu has gone on to realize some very important projects in China, is has been very excited to share his vision of the “mountain-water city” with the Chinese media.

After finishing the plans for the Olympic Forest Park, Hu designed two major projects (amongst others) that exhibit his commitment to the ancient philosophies regarding the balance of rock and water, and the unity of man and nature. The two major projects are the Tieling New City in Liaoning Province and Nanhu, Tangshan, Hebei Province. The design for Tieling New City mainly featured a man-made canal system with water diverted from Fan River into a wetland lotus park to serve as a recharge system for water resources. There were also green buffer zones to protects natural rivers from highways that cross at a man made lake called “Lake of Wishes”. Th soil displaced from the man made canals and lakes were used to build artificial mountains to shield the lotus wetland. His design of Lotus Lake International Wetland Park in Tieling won multiple awards from all over the world. Dr. Hu’s work can be seen all over China in successful projects from the master plan of Qinghai Province’s Kanbula Scenic Area to Fuzhou University’s new campus proposal.

Actually, the concept of a “mountain-water city” and an “eco-city” do not seem to differ much aside from perhaps the incorporation of traditional Chinese style and philosophy. But in many senses—their aim is the same—to integrate man’s environment with a more natural environment, to utilize natural resources in an efficient way, and to create better ways of living and healthier lifestyles. So why is it that recently it seems that there is a lot of media on foreign-led eco-city plans that fail in the end? The possibilities are endless—a question of selective reporting? A problem with the communication of expectations between designers and developers? A governmental red-tape problem? In the end though, we know that through the work of Qian Xuesen and Hu Jie, that Chinese concepts and versions of eco-cities have been carried out through construction and do exist.

Water Scarcity in China—Addessing a problem of quantity, quality and management

May 14th, 2010 by

Along with its rapid economic development and rising water demand in the past few decades, China has also been experiencing increasingly severe water scarcity. The overexploitation of both surface water and groundwater resources has led to serious, often irreversible, environmental consequences including salt water intrusion, ground subsidence, and ecological degradation. In addition, as we have seen in recent reports from the Southern China drought, pollution often makes already scarce water resources unfit for consumptions and even agricultural use.  In recent years, China’s water demand and the growing concern of water scarcity has been covered by major media including the New York Times and the Economist.

Major concern is that coupled with the increasing urbanization, China’s farmlands will not be able to support the country’s population and unmet industrial demand for water will slow GDP growth. According to a 2002 World Bank report, since the 1980’s China has been experiencing water shortages of increasing severity in the areas of urban industry, domestic consumption and irrigated agriculture. In 2007, China’s Ministry of Water Resources reported that total national water deficit is estimated to be 30-40 billion cubic meters per year, and even more during drought years. Because of insufficient surface water resources, and because groundwater is generally less susceptible to contamination than surface water, groundwater extraction in many areas of China has become a main source of water resources. Unfortunately, because the recharge rates of such sources is also much slower (often deep aquifers have recharge rates are on the order of thousands of years), extraction rates have exceeded recharge rates. Depletion of groundwater resources has led to a continuous water table decline of 0.5 meters per year. It is reported that since 1960, water table declines have reached 40 meters for shallow groundwater and more than 40 meters for deep aquifers. The lowering of the water table and decline in soil pore pressure has led to irreversible ground subsidence. Areas around Beijing have been reported to land subsidences of up to several meters.

China's River Basins

Surprisingly, China is estimated to rank fifth in the world for renewable water resources after Brazil, Russia, Canada and Indonesia. According to sources, the spatial and temporal distribution of renewable water resources and their inefficient management, pollution, as well as increasing per capita water demand are the major causes for severe water shortages in many areas. For example, northeastern China, which is known as China’s breadbasket, accounts for two-thirds of the nation’s farmland, but has only one-fifth of the country’s water resources. Also in northern China, 78% of surface water bodies in the Hai River Basin, to which Beijing and Tianjin, and Hebei Province belong, have been classified as “poor”, unfit for drinking and recreational use. Thus, the spatial distribution of water resources and poor water quality mutually exacerbate the situation in northern China.

Quality of Surface Water in China. Source:

Quality of Surface Water in China. I-III Considered "Good", IV-V+ "Poor". Source:

In the past, water resource management in China has been predominantly supply-driven, meaning that few limitations were placed upon water usage and demand, and large engineering projects, such as the South-North Water Diversion Project, were implemented to meet those demands. This imbalance between supply and demand regulation led to an inefficient industrial and agricultural structure and water use. The Chinese Academy of Science reported in 2007 that China’s water use for industry-added value was 5-10 times the levels of developed countries and that industrial water recycling was only half of that of developed countries. Other reports indicated that only half the amount of water diverted by canals for irrigation actually delivered to the field and that only 40% of groundwater extracted for irrigation was actually used on crops.

In 2009 however, the New Scientist reported that Water Resources Minister Lei Chen that by 2020, China would cut the amount of water needed to produce each dollar of GDP by 60% by placing more restrictions on water demand. Such action would work towards China’s supply-driven strategy in battling water scarcity.

By improving regulation and management of water resources, China will be more in a better position to deal with the rising demand of water resources, a growing population,  and rising GDP. However, such regulation must be supported by a holistic infrastructure institutional systems including legislature, governing bodies, monitoring, , non-profits, and academia.

Beijing’s Green Lungs and Kidneys: The Olympic Forest Park

April 19th, 2010 by

Local Beijingers like to give colloquial nicknames to the prominent architecture in the city. In the period leading up to the Beijing Olympics, the more notable were probably the “Bird’s Nest”, “Watercube” and the “Giant Underpants” (new CCTV building), but the 2008 Games also left behind a pair of “green lungs and kidneys” for Beijing: the Olympic Forest Park.

An aerial view of the Beijing Olympic Forest Park, the North-South Axis can be seen at the top of the photo, and the "Bird's Nest" is located on the top left

Amidst the numerous reports on Beijing infamous air quality, perhaps overlooked by many foreign media was Beijing’s biggest project to show its dedication to improving air and water quality in its natural environment. Indeed, the Olympic Forest Park was also a feature to sell Beijing’s commitment to environmental issues in the Olympic bid. And, unlike the temporary closing of nearby factories and strict car bans to improve air quality during the games, the Olympic Forest Park is here to stay, a permanent symbol of China’s intent to better its environment and utilize nature resources more efficiently.

Plans for the Olympic Forest Park began in 2003, with an official decreement on the development of the park in accordance with Beijing Municipality’s development goals. The park, which occupies an area of 680 hectares, was planted with over half a million trees, and reused 4 million cubic meters of soil from the construction of the Beijing National Stadium (The Bird’s Nest) and the Beijing National Aquatics Center (The Water Cube). It is designed to not only have zero carbon emissions, but to also act as an urban carbon sink, cutting down Beijing’s air pollution by absorbing up to 7,200 tons of carbon each year. In addition, the park also abosorbs 32 tons of sulfure dioxide, purifies 5,400 tons of oxygen and retains 4,905 tons of dust for the city annually, thus the nickname, “the green lungs of Beijing”.

Besides being a green haven on Beijing’s central axis, the park also incorporates traditional aspects of Chinese landcape design, balancing bodies of water with rock, mountain and green space to produce the epitome of a fengshui garden to the north of the city’s center. According to traditional fengshui belief, mountains at the north of the city and a southern flow of water toward the city center is very auspicious. For this reason, the park was placed right at the north end of Beijing’s North-South Axis, linking China’s environmentalism and symbols of modernity such as the Brid’s Nest and Water Cube, to its rich history with the Forbidden City and Tiananmen Square at the southern end. The flow of water to complete the fengshui masterpiece was key.

4.15 hectares of wetlands prevent eutrophication of the park's water bodies

However, Beijing suffers from severe water scarcity problems. While the plan for Olympic Forest Park called for a dragon-shaped lake, the source for the water to fill the lake was an issue nobody could overlook. In order to address this problem without placing more stress upon the municipal water supply, the Olympic Forest Park is designed to use reclaimed water from Qinghe Wastewater Treatment Plant. The effluent from Qinghe Secondary WWTP which is rated as Category V by national standards, has high levels of the nutrients nitrogen and phosphorous and could therefore lead to the eutrophication of the proposed 20.3-hectare lake. To address this problem the secondary reclaimed effluent is designed to first flow a system of integrated vertical flow wetlands before entering the lake. Water from the lake is also periodically pumped back through the wetlands, which are able to uptake excess levels of nitrogen and phosporous to ensure that the water in the lake meets national standards for Category III surface water. The 4.15-hectare wetland system, which consists of 6 parallel integrated vertical flow wetland units, has been in place for close to three years now, and has been confirmed to raise the quality of the lake water by processing about 2,600 cubic meters of reclaimed water and 20,000 cubic meters of cycled lake water per day, thus the nickname “the green kidneys of Beijing”.

Olympic Forest Park is a natural habitat for many local flora and fauna

In 2009, The team for Olympic Forest Park was the only Chinese company to receive an ASLA award. The team was led by Tsinghua University Associate Professor Dr. Jie Hu. Hu is currently spearheading a movement in China called “Water-Mountain” Cities (山水城市), that incorporate the tranditional balance of Chinese nature into urban design.

Sand! Storm!

March 22nd, 2010 by

Below are some pictures I took on March 22 and March 23 in northwest Beijing. The major sandstorm reported on by major news sources occurred on March 20th, though conditions on the morning of the 22nd were also quite sandy. A contrast picutre taken on March 23 is provided.

Noon on March 22nd, the air is full of sand!

Noon on March 23, blue skies, better visibility!

Xinhua News Agency reported that during the March 20th sandstorm, a total 300,000 tons of sand from the north entered Beijing Municipality.

The People’s Daily also reported on “Muddy Rain” in Inner Mongolia originating from the unfortunate coincidence of a sandstorm with rain.

Here are some interesting photos from Xinhua News Agency:

A car covered in dust from the 3/20 sandstorm in Beijing. Characters read: "little dust". Photo: Xinhua News Agency.

People pose for a picutre outside the Forbidden City in Beijing during the 3/20 sandstorm in Beijing. Photo: Xinhua News Agency

Pictures from March 14th snowfall

March 22nd, 2010 by

Below are some photos I took around northwest Beijing in the universities area showing street conditions after a large snow. That day we got about 3-4 inches of snow.

Water and slush at accumlate at an intersection making it difficult for bikers and pedestrians to navigate the road.

A woman walks up the street from the intersection to find a place to cross the road

In the area in front of a shopping mall, snow and water are pushed with shovels into a manhole

In the news… 3/10/10

March 11th, 2010 by

The following are some relevant articles from China’s government-sponsored English-language newspaper, The China Daily:

  1. Warplane bombs Yellow River ice jam
  2. Severe drought in SW China likely to linger till May (Xinhua News Agency, reposted in English on China Daily)
  3. Rain to be created in drought provinces: “In an effort to create rain, the China Meteorological Administration (CMA) said that weather bureaus in the affected regions are ready to “bomb clouds” with 2,116 doses of silver iodide, a compound used in cloud seeding, for which 2 million yuan ($294,000) has been allocated”
  4. Joint efforts against water pollution (Taihu Lake)
  5. City governments fined for Yellow River pollution: “The governments of Xi’an and Xianyang, two major cities in northwest China’s Shaanxi Province, have been fined a total of 500,000 yuan ($73,530) for polluting a tributary of the Yellow River, China’s second longest waterway”

Premier Wen’s visit to drought-stricken Guangxi Province

March 4th, 2010 by

Happy Chinese New Year!

This year’s Spring Festival fell on February 14th, 2010. The Spring Festival, usually celebrated over a period of 15 days, is the most important holiday in Chinese culture and millions of people flock home to be with family. The eve of the Chinese New Year is customarily celebrated by reuniting with one’s family, eating dumplings or rice cakes, catching up with relatives, and setting off firecrackers. For millions of migrant workers all over China, the few days of the national holiday represent the only time to see one’s children and parents, sometimes even one’s own spouse, left back in rural villages.

For some however, the pilgrimage home also represents the stark difference between the distribution of resources in urban and rural areas. On February 13th, Xinhua News Agency reported on one region in particular, in southern China, that is currently experiencing severe drought. According to the report, after the Central Committee of the Communist Party of China and the State Council’s Spring Festival Celebration, Premier Wen Jiabao immediately flew to the drought region to show support for the local residents of Hechi, in Guangxi Province.

Some villages in Guangxi Province, home of the breathtaking landscapes of the city of Guilin , have experienced drought conditions since August of 2009

Beginning in August of 2009 the region, which has been designated as a key recipient for central economic aid, has experienced high temperatures with little rainfall. The result has been the depletion of water storages, the interruption of local river flow and water scarcity for residents, agriculture and livestock. Compared with the previous year, per capita water availability dropped by 60%. In response, 385 water distribution stations were built to provide water to drought-stricken areas. Currently, water is distributed by car and each resident receives 20 kilograms of water per day. Local residents expressed to Premier Wen that for the New Year’s festivities, this amount was enough. In contrast, according to the American Water Works Association, the typical indoor daily water usage in a United States single-family home is 262.3 liters.

2: Premier Wen Jiabao visits villages in Guangxi Province to promote drought relief efforts. Water distribution stations provide 20 kilograms of water per person per day. Source: Xinhua News Agency, photographer: Liu Dawei.

Upon leaving, Premier Wen stressed the importance of ensuring the distribution of clean, safe water not only for residential use, but also to ensure use for livestock, local agriculture, and production. The region’s primary agriculture products include rice, corn, silk, and soy. The premier also expressed that the long term solution to the region’s water scarcity problems had to be connected to the planning water system infrastructure including, reservoirs, irrigation systems, and water storage tanks.

Premier Wen’s New Year’s Eve visit to the drought-affected areas in Guangxi Province not only moved local residents, it also represented the national concern over water scarcity issues and the need to improve rural water infrastructure.

Fluorosis: an issue of safe drinking water and energy consumption

March 3rd, 2010 by

The occurrence of fluorosis, a medical condition that affects both the growth of healthy teeth and in extreme conditions can cause deformation of skeletal structure leading to crippling, is one manifestation that attests to the intersections between two environmental issues: safe water supply and energy consumption. UNICEF has reported that China is one of countries with the greatest number of dental and skeletal fluorosis cases in the world. The World Health Organization estimates that 2.7 million people in China have skeletal fluorosis and Chinese sources’ estimates range from 2 million to 2.8 million cases of skeletal fluorosis while 38 million people suffer from the dental form.

While fluorine is essential for the healthy development of teeth, over-exposure of fluorine—either by ingestion, skin contact, or inhalation—can cause yellow, brown and eventually black staining of the teeth, and in extreme cases, deformation and pain of bones and joints.

Reports on fluorosis in China usually either focus on cases from impoverished regions in the south, or cases from the northeast. In actuality, the causes for the prevalence in these two regions are different; in northeastern China, the source of excess fluorine is groundwater that does not meet national drinking water standards, while in southern China, the mining and consumption of sub-standard coal is the main source of over-exposure. The difference in the exposure sources represents an overall picture of natural geography and environmental safety of China.

A man with skeletal fluorosis. Often entire villages suffer from this endemic disease resulting from coal and water resources.

China, especially northern China relies heavily on groundwater, which can contain metals and other pollutants in high concentrations, for domestic usage. Fluorine is one of such elements. Although Fluorine is nationally regulated to 1 mg/L in drinking water, it is often found in amounts far above that. In a recent study on the geological background and source of fluorine in drinking water in China found that fluorine in groundwater ranges from 1-22mg/L in Shandong Province, 1-22mg/L in Shanxi Province and 1-12mg/L in Shaanxi Province. In some rural areas, drinking water may not be properly treated, resulting in residents’ exposure to fluorine. Northern China is rich in coal deposits, which can lead to higher concentrations of fluorine in groundwater.

The reports that focus on skeletal fluorosis in southern China however do not draw as much attention to ingestion of sub-standard drinking water, but rather to coal mining and consumption. However, compared to northern China, the south is poor in coal deposits. Why then, is most coverage on fluorosis in the south focused on the inhalation of coal fumes? There are two reasons. One, precisely because coal deposits are more scarce in the south, a powdery form of coal is mined out and mixed with clay to make into coal bricks. The additional clay content contains an amount of fluorine ten times the amount in the coal itself and when the coal bricks are burned, poor ventilation causes high exposure to residents. Secondly, because of the wet local climate, vegetables that are customarily dried for winter storage must be smoked in order to be effectively preserved. The smoke, which comes from burning high-fluorine coal bricks, is absorbed into drying corn and peppers, and ingested orally, adding to rural residents’ already high fluorine exposure.

For the past twenty years the Chinese government has been cooperating with international organizations to decrease risk from the slow poisoning effect of fluorine. In the south the central government even allocated funds to change and upgrade furnaces to reduce coal fumes. In the north, water treatment methods are constantly being upgraded. In at least the last three Five-Year Plans, the issue of fluorosis was addressed, with goals for decreasing the prevalence of the disease, whose effects range from social discrimination because of stained teeth to citizens who are completely crippled by the age of 40. Because coal and water in themselves are considered scarce commodities in some areas however, the battle to decrease fluorosis in China will continue to be an issue in coming years.

The occurrence of fluorosis, a medical condition that at affects both the growth of healthy teeth and in extreme conditions can cause deformation of skeletal structure leading to crippling, is one manifestation that attests to the intersections between two environmental issues: safe water supply and energy consumption. UNICEF has reported that China is one of countries with the greatest number of dental and skeletal fluorosis cases in the world. The World Health Organization estimates that 2.7 million people in China have skeletal fluorosis and Chinese sources’ estimates range from 2 million to 2.8 million cases of skeletal fluorosis while 38 million people suffer from the dental form.

While fluorine is essential for the healthy development of teeth, over-exposure of fluorine—either by ingestion, skin contact, or inhalation—can cause yellow, brown and eventually black staining of the teeth, and in extreme cases, deformation and pain of bones and joints.

Reports on fluorosis in China usually either focus on cases from impoverished regions in the south, or cases from the northeast. In actuality, the causes for the prevalence in these two regions are different; in northeastern China, the source of excess fluorine is groundwater that does not meet national drinking water standards, while in southern China, the mining and consumption of sub-standard coal is the main source of over-exposure. The difference in the exposure sources represents an overall picture of natural geography and environmental safety of China.

China, especially northern China relies heavily on groundwater, which can contain metals and other pollutants in high concentrations, for domestic usage. Fluorine is one of such elements. Although Fluorine is nationally regulated to 1 mg/L in drinking water, it is often found in amounts far above that. In a recent study on the geological background and source of fluorine in drinking water in China found that fluorine in groundwater ranges from 1-22mg/L in Shandong Province, 1-22mg/L in Shanxi Province and 1-12mg/L in Shaanxi Province. In some rural areas, drinking water may not be properly treated, resulting in residents’ exposure to fluorine. Northern China is rich in coal deposits, which can lead to higher concentrations of fluorine in groundwater.

The reports that focus on skeletal fluorosis in southern China however do not draw as much attention to ingestion of sub-standard drinking water, but rather to coal mining and consumption. However, compared to northern China, the south is poor in coal deposits. Why then, is most coverage on fluorosis in the south focused on the inhalation of coal fumes? There are two reasons. One, precisely because coal deposits are more scarce in the south, a powdery form of coal is mined out and mixed with clay to make into coal bricks. The additional clay content contains an amount of fluorine times the amount in the coal itself and when the coal bricks are burned, poor ventilation causes high exposure to residents. Secondly, because of the wet local climate, vegetables that are customarily dried for winter storage must be smoked in order to be effectively preserved. The smoke, which comes from burning high-fluorine coal bricks, is absorbed into drying corn and peppers, and ingested orally, adding to rural residents’ already high fluorine exposure.

For the past twenty years the Chinese government has been cooperating with international organizations to decrease risk from the slow poisoning effect of fluorine. In the south the central government even allocated funds to change and upgrade furnaces to reduce coal fumes. In the north, water treatment methods are constantly being upgraded. In at least the last three Five-Year Plans, the issue of fluorosis was addressed, with goals for decreasing the prevalence of the disease, whose effects range from social discrimination because of stained teeth to citizens who are completely crippled by the age of 40. Because coal and water in themselves are considered scarce commodities in some areas however, the battle to decrease fluorosis in China will continue to be an issue in coming years.

News: Algae-eating fish to improve conditions of Taihu Lake

March 2nd, 2010 by

On February 2, the China Daily (Xinhua News Agency) reported that government funds and public donations were put to use in the purchase of 330,000 silver carp fry to help reduce algae in Taihu Lake. Taihu Lake is China’s third largest freshwater body and experienced a choking algal bloom resulting from agricultural runoff (high in nitrogen and phosphorous content)  in 2007. Since then, national and local governments and organizations have utilized many methods to improve the lake’s conditions.  The use of silver carp to clean the lake began in February 2009.






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