The pursuit of clean drinking water and treated sewage: helping refugees in Thailand and residents in Honduras
By Denise Brehm
Civil & Environmental Engineering
Many graduate students in the environmental and water quality engineering track of the Civil and Environmental Engineering M.Eng. program spend IAP in the developing world conducting research that improves systems essential to good health: drinking water and sewage.
This year, students from two of those teams are keeping blogs so that other members of the MIT community can participate in the work vicariously. Katherine (Kat) Vater will report from the Mae La refugee camp in Thailand, and Anne Mikelonis writes from Las Vegas, Honduras.
Clean water for all
Three grad students in the program—Mary Harding, Navid Rahimi and Vater—are working in the Mae La refugee camp in Thailand this month to evaluate and improve the camp’s drinking water distribution system.
One of several refugee camps in Thailand that have existed for more than 20 years on the Thai-Burmese border, Mae La is home to about 20,000 Burmese from the Karen mountain tribe who fled their homeland to avoid violent persecution. Other camps house refugees from the Karenni and Mon peoples. With no rights or recognition outside the camps and facing the possibility of death if they return to Burma/Myanmar, the refugees are wholly dependent on international aid for their subsistence. (Because the U.S. and many other governments do not recognize the name change, the country is often still referred to as Burma or as Burma/Myanmar.)
Drinking water for the residents of Mae La comes primarily from two locations in a nearby river and 13 natural springs. Almost all of this water is chlorinated at storage tanks before being distributed through 152 taps turned on in three-hour periods twice daily when residents fill containers for household use. Refugees also have access to non-drinkable water (contaminated by heavy metals), which is available through 17 borehole wells with hand pumps and 63 rope-pump wells.
Following a persistent cholera outbreak in the camp, tests performed in 2007 on the treated water showed adequate chlorination at the distribution point, but tests on water from these same sources stored in household containers revealed low chlorine levels and prominent bacteria contamination.
The MIT team will focus its efforts on the spring water sources for Mae La, with the goal of improving overall quality through better water treatment processes and possible redesign of the distribution systems. Using the information they gather, Harding, Rahimi and Vater will continue their work at MIT this spring and present their final report to the client, Aide Medicale Internationale (AMI), in May. Each will also write a master’s thesis based on his/her aspect of the research project.
The changes recommend by the team, if implemented by AMI, could greatly benefit the people at Mae La, many of whom have spent their entire lives in the camp. More than 100,000 people live in similar camps, and another 200,000 to 400,000 people are scattered along the border outside the camps.
Recent massive resettlement of refugees in the United States and other countries may have reduced those numbers somewhat, but refugees continue to pour across the Burmese border to escape violence in the country that now calls itself Myanmar. For refugees new to Mae La and for those who choose not to resettle in a foreign land, improved drinking water in the camp will make life a little easier.
A second MIT team—Matt Hodge and Mikelonis—is in the Central American city of Las Vegas, Honduras, this month, evaluating the town’s wastewater treatment facility. Las Vegas is a city of about 17,000 people on Lake Yojoa, which lies just south of San Pedro Sula. As the largest lake in Honduras, Lake Yojoa is one of the country’s most popular tourist destinations and is known worldwide for its fishing and the diversity of birds and plant life living in the surrounding area.
Hodge and Mikelonis will inspect and make recommendations for improving the Las Vegas wastewater treatment facility, which was built in 1992 and has received no significant maintenance in its 15 years of operation. The system, to which about 30 percent of the city’s population is connected, collects wastewater in open culverts that flow to two Imhoff tanks. Suspended solids settle out in the upper portions of the tanks, and the resulting sludge is collected and digested in the lower portions. As the tanks and treatment system have aged and fallen into disrepair, sludge has not been removed, resulting in poor treatment of the wastewater before it is discharged into Raices Creek, which empties into Lake Yojoa. Similar conditions afflict many other wastewater treatment systems throughout Latin America.
The city’s planned expansion of its sewer system should be completed this month. One of the goals of the MIT team is to evaluate the adequacy of the existing tanks to handle the increased loading. Another goal is to assess the advantages of including an additional water treatment, called Chemically Enhanced Primary Treatment (CEPT), to the present system to see if it might be added to the expansion at a later date. CEPT uses metallic salts such as ferric chloride to enhance the removal of solids from the water, which increases the efficiency of treatment, and hence allows greater flow rates.