February 02, 2009 —

Knowing that two years of work may soon change over 300 lives is a good feeling for junior Liana Ching.

Since her freshman year, Ching, through the Viterbi School of Engineering’s undergraduate group Engineers Without Borders, has

Sign up· Junior Alex John, president of the USC chapter of Engineers Without Borders, records new member information at a meeting.

waded through plans, calculations and fundraising to design a water purification system in two villages in an arid, rural region of southwest Honduras.

Now, after fundraising efforts helped earn the last of the $60,000 needed for the project, construction in La Estanzuela, one of the villages, might begin in as little as two months.

“There’s so many things that go into a project of this size and scope, especially when it’s in a foreign country,” Ching, a chemical engineering major, said. “It’s such a relief to see it almost finalized after it’s been such a constant project on evenings and weekends.”

But, Ching said, before construction can begin, the Engineers Without Borders national technology advisory board must approve the La Estanzuela project.

“Engineers Without Borders is a national organization with chapters in many places,” Ching said. “We found this project through the national organization, so they have to look at our work and make sure that what we’re going to build is accurate.”

The project has an unconventional design because the village has no electricity.

“There’s no power in these rural villages,” said faculty adviser Mansour Rahimi. “We knew that from the surveys that it wouldn’t be connected, so pumping devices would have to run some other way.”

After toying with the idea of a hydraulic ram pump, which would have cost the group almost $8,000 and created less water pressure, Ching and her co-workers instead decided on a cheaper, more efficient option.

“They decided to use a paddle wheel design, which they’ve designed to be placed slightly upriver at a dam,” Rahimi said. “When water falls over the wheel, it spins and generates power.”

Because the village is at a higher altitude than the river, Ching said the pump must generate enough energy to pipe the water nearly 80 meters vertically.

“The river is the primary source for all of their water needs, which includes laundry, water to flush latrines, cooking, cleaning and bathing,” Ching said. “We saw people swimming in the river, washing their clothes with soap, while cars drove through and wild horses wandered around. And this is the water that they’re also drinking.”

To combat this problem, Ching’s team added purification steps to the process: once the water falls over the wheel, it goes through a sedimentation tank to help remove the solid, contaminated particles.

Then, the water flows through a 10,000-gallon cement storage facility with chlorination tanks on. After the water is clean, it goes through a PVC gravity-feed distribution to transport the water to the village. 

“Our goals are quantity and quality,” said Alex John, the president of Engineers Without Borders and a junior majoring in environmental engineering. “By quantity, we mean enough for every person. By quality, we mean cleaner water, without the sedimentation or bacteria.”

Although Ching and her partners said they could have found an easier way to create the pump, they had to focus instead on a way that was understandable for the rural villagers.

“Our goal is not to provide a pump that will last 15 years,” Ching said. “Our goal is to build a water system that they have the financial and technological capacity to maintain forever.”

Once the construction begins, John said several group members will travel to Honduras to supervise construction and help install a paddle wheel, a vital part of the system’s construction.

Students who attended the first Engineers Without Borders meeting on Jan. 29 expressed interest in helping finalize the La Estanzuela project and work more closely on the design for Corral de Piedra, which the group began in the spring of 2007.

“I’m new, but I’m looking forward to a real-world experience,” said Nathaniel Ahlers, a sophomore majoring in civil engineering. “It’s an opportunity to work as a student on a project that has the potential to change lives.”

Kristy Beal, a sophomore majoring in civil engineering who has been a part of Engineers Without Borders, said she would see the project through to the end.

“We actually get to see the application of what we learn in class,” Beal said. “And we’re helping people, too.”