Engineering change: Finding clean water for the slums of Buenos Aires

Finding clean water for the slums of Buenos Aires

Rebeca Hwang was 11 years old the first time she treated contaminated water. It flowed clear and cold from the taps of her family home in Buenos Aires, Argentina.

She recalls herself, a pigtailed, South Korean native, watching her nanny and mother dribble cholera-killing bleach into 12 liters of boiled water, the daily supply for Hwang's family. For two years, the Hwangs, along with millions of other families in South America, cooked with, cleaned with, and drank these bleach solutions to outpace a nearly continent-wide cholera epidemic.

The later realization that developed nations had avoided the 1991 epidemic thanks to advanced resources spurred Hwang, now 27, to design water treatment technology for regions in dire need. With undergraduate and graduate engineering degrees from the Massachusetts Institute of Technology, Hwang has gotten to know the ins and outs of treatment ecosystems in rural India and Nicaragua, from designing advanced, yet affordable filtration devices, to monitoring improvement levels. In her work, she has scooped samples from wells and streams so visibly tainted, the thought of them still makes her queasy.

"You see the most disgusting water sources," Hwang remembered, "with contamination so visible that (many people) would throw up before drinking from there--and then you see women collecting water to cook with."

In such field conditions, Hwang became a believer in sustainability. Technical approaches are crucial, she thought, but without efficient systems for distributing freshly treated water, they offer only half a solution. Hwang determined that improving water distribution would require an intimate knowledge of local agency structures and politics to succeed in creating a program of lasting progress.

Now a Stanford University Ph.D. student in an interdisciplinary program that encourages solving real-world environmental problems, Hwang has an ambitious plan for boosting the power of water treatment technology in Argentina, particularly Buenos Aires' under-serviced outskirts. She'll do it using her cultural currency, technical know-how and a quantitative theory of social networking that the U.S. has also used to thwart terrorist rings. She'll use specialized software, but not a single treatment or filtering device.

"Typically, the main stumbling block isn't the technology," explained water treatment expert Leonard Ortolano, Hwang's adviser at Stanford. "Oftentimes the roadblocks are financial and institutional."

A 'science queen'
Hwang was born in Seoul, South Korea, the younger of two children. When she was 6, the family uprooted in response to civil unrest and joined a small community that had migrated to Buenos Aires. A self-described "queen in science," Hwang earned top honors in various national competitions while honing skills in dance and sports.

When she began thinking about college, the still-Korean citizen petitioned her parents, and even Argentina's Korean ambassador, to support her move to the U.S. for an education. Hwang's parents weren't thrilled by their 15-year-old daughter's request, "but as soon as they saw how hard I was working to get all the paperwork done," she said, "they changed 180 degrees and supported me the whole way."

Despite a second language barrier, to English this time ("you should have seen me trying to curse!"), Hwang's academic and social successes continued at MIT, where she won a grant and first place in two competitions focusing on social development.

Video: Water for developing Argentina
Engineer Rebeca Hwang talks about her work to strengthen water co-ops and bring clean resources to Buenos Aires' underprivileged.

Life in the outskirts can be rough, the poor tenants scraping by in nearly cut-off conditions to remain close to their low-paid jobs in the capital. Half live in poverty. There aren't enough government resources to spill into the unregulated outskirts, so communities must fend for themselves, forming coalitions to pump treated water into taps.

Hwang believes consistent distribution services will bring clean water to more people. In South America, Hwang explained, up to 70 percent of a city's water is provided by small-scale community cooperatives whose neighborhood-by-neighborhood service resembles quilt patches sewn loosely together. Co-ops are, in turns, haphazardly managed and hindered by internal bureaucracy. Even with trained professionals at the helm and a modicum of essential business practices in place, co-ops frequently leak expenditures that should cycle into treatment and delivery programs.

"Water is a good that follows economies of scale," Hwang said. Treating water for 100,000 households is cost-efficient, but at an average of 2,000 houses each, the revenues evaporate.

Yet Hwang believes a mathematically structured analysis called social networking may be the key to co-ops' more effective operation. To think about social networks, envision a studded pin board, with each pushpin connected by a length of string. The pins represent organizations or individuals of the same type, called agents or "nodes." The strings stand for the relationship tying two nodes together. These "ties" can denote goods, services or even technology, such as a wireless connection.

Hwang proposes that mapping the relationships between decision-makers at water cooperatives will reveal how the individuals within follow patterns for giving and receiving resources and information. For example, if managers A, B and D make decisions four-fifths of the time, it's a good guess they'll do so again. Predicting patterns can indicate an organization's strengths and weaknesses, and identify ways to improve efficiency.

"These calculations give you a sense of who the central nodes of the network are," Hwang said. For example, "who is popular...you are able to know some very important characteristics of the structure or architecture of the network."