STUDENT RECEIVES FELLOWSHIP TO TEST NEW WATER SYSTEM

In the summer of 2012, Valerie Bauza (Civil and Environmental Engineering) received a fellowship from the Center for South Asia to conduct field tests on a hand pump water chlorinator based around community-level disinfection in Dhaka, Bangladesh. 

“Previous work has found that drinking water in Dhaka slums is often contaminated at the point of collection and it is likely that this water is becoming contaminated as it travels through a poorly maintained distribution network,” reports Bauza. “As a result, there is inadequate access to safe drinking water for this low-income urban population, resulting in sickness, disease and death.”

Typically, water contamination issues are addressed either at the city-wide level by providing improved water treatment prior to distribution, or at the household level by providing point-of-use drinking water treatment. However, in Dhaka, implementing a city-wide water treatment system is cost prohibitive and the team knew that residents tend to dislike the taste of chlorinated water.

During the 2011-2012 academic year a team of Stanford students worked on the chlorinator design so that it would chlorinate drinking water and remove microorganisms that cause diarrheal diseases.  Students involved in the design were Yoshika Crider (Civil and Environmental Engineering), Keegan Cooke (Civil and Environmental Engineering), Kara Bennett (Energy Resources Engineering), Camil Diaz (Chemical Engineering), Isaac Madan (Computer Science), Nabil Mansouri (Civil and Environmental Engineering), and Olivia Vagelos (Product Design).  All students were members of the campus branch of Engineers for a Sustainable World (http://www.eswusa.org/).

The design was thoroughly tested in the research lab at Stanford and field testing began during the first week of July and lasted three months.

“However, when we began field testing in Dhaka, we realized that the field conditions, particularly pressure and flow variations, were different from the conditions at Stanford,” says Bauza.  Due to these differences, the team had to adapt the design to the local conditions so that it was capable of consistently dosing drinking water at a goal level of 0.5-1.5 mg/L free chlorine. 

After the field testing, the pilot study began in mid-August 2012 and will end mid-January 2013.  The study is being conducted at 20 shared water points that serve more than 300 households.  The handpump chlorinator was installed at 10 water points; Aquatabs point-of-use household-level water chlorination technology were provided to households at 5 of the water points; and the remaining 5 water points will serve as control households.  At the 10 water points receiving a handpump chlorinator, the level of water chlorination was gradually increased at 5 of them during the first two weeks of the study to determine if this would result in greater community acceptance of chlorination.  Biweekly surveys will occur as well as water quality testing of household stored water and water source.

“In addition to being effective, it’s important that users accept the chlorinator,” says Bauza.  “We also hope to overcome user resistance to the taste and smell of chlorine.”   

Bauza’s summer research was completed in collaboration with the International Center for Diarrheal Disease Research, Bangladesh (ICDDR,B) under the guidance of Dr. Steve Luby, Research Director for the Center for Innovation in Global Health at Stanford University; Dr. Jennifer Davis, professor in Civil and Environmental Engineering at Stanford University; and Dr. Amy Pickering, post-doctoral student at Stanford University and ICDDR,B research affiliate.  This work is being funded through a USAID grant to ICDDR,B as well as EPA P3 project funding received by the team at Stanford.