Two recognized experts in drinking water contamination and water chemistry – including the professor who led the investigation into lead contamination in Flint, Mich. – are working with the city of Fresno to find solutions to the corrosion of galvanized residential plumbing in the northeast part of the city.
Marc Edwards, a professor of civil and environmental engineering at Virginia Tech, and Vernon Snoeyink, a professor emeritus in the civil and environmental engineering department at the University of Illinois at Urbana-Champaign, have been utilized by Fresno’s public utilities department since February, after a growing number of reports began surfacing about discolored water coming from faucets at homes across northeast Fresno. As of late July, nearly 800 residents had responded to an online survey posted by the city in June to report discolored water. Results of subsequent water-sample testing at nearly 300 homes showed that 51 had excessive levels of lead in the water.
Edwards is an authority on water systems, with a research interest in water treatment, corrosion, arsenic removal and water system chemistry. He led the Virginia Tech research team that investigated the highly publicized problems of contamination from lead pipes throughout the municipal water system in Flint as a result of improper corrosion control treatment. Edwards was the 2012 recipient of the Barus Award for Defending the Public Health and Interest from the IEEE-Society on Social Implications of Technology for his two decades of work to expose lead contamination in the drinking water in Washington, D.C.
Snoeyink, whose research area is environmental engineering and science, retired from the University of Illinois at Urbana-Champaign in 2005 but continues to hold memberships with the National Academy of Engineering, the American Society of Civil Engineers, the American Water Works Association, the Association of Environmental Engineering and Science Professors and the International Water Association. During his career as a professor and scientist, Snoeyink has been recognized with research awards from the American Water Works Association, the University Council on Water Resources and the American Society of Civil Engineers.
“They’ve both been working with us since February specifically to analyze the water chemistry and our water system anti-corrosion measures,” said Mark Standriff, a spokesman for the city.
Complaints about discolored water in northeast Fresno date as far back as 2004. That’s the year that the city, which had historically relied solely on pumped well water for its drinking water supply, began introducing Enterprise Canal water, treated at the Northeast Surface Water Treatment Facility, into the system serving northeast Fresno. In addition to disinfecting and filtering of the water, corrosion-control chemicals are added and the water is blended with pumped well water before it flows through the city’s water mains.
Fresno’s water division, as well as the State Water Resources Control Board, maintain that what gets delivered to homes in the city’s system is safe and meets all state and federal standards for drinkability. But the issues revolve around what happens when the blend of surface and pumped water interacts with the galvanized household plumbing in affected homes. Surface water has different temperature, chemical and pH characteristics than water pumped from wells. Those different characteristics can degrade protective mineral scales that form over time on the inside of pipes and allow corrosion to happen faster.
In recent months, the city has been incrementally adjusting treatment at the water plant, including pH and anti-corrosion chemicals, to see what effect it has on discoloration and lead levels in follow-up testing at affected homes. Those adjustments, the city reported last week, had managed to reduce the number of homes showing excessive levels of lead from 51 to 41.
Standriff said the city expects to receive reports from both professors within days.