Expert says better chemistry key to solving northeast Fresno water woes

A noted national expert in water-system engineering said Fresno still has considerable work ahead of it as it deals with persistent water problems in the northeast part of the city.

Local, state and federal water officials offered weary – and wary – northeast Fresno residents an update Wednesday night on those persistent water problems.

A growing number of northeast Fresno homes showing discolored water from faucets, and a rise in the number of homes testing positive for lead in the water, spurred 500 residents to the meeting at Clovis West High School.

Vernon Snoeyink, a professor emeritus in the civil and environmental engineering department at the University of Illinois at Urbana-Champaign, is one of the experts being called on to help the city. He said he has evaluated data from water samples collected by Fresno’s water division from affected homes since January. He reported that his team believes a major factor in the corrosion problems contributing to discoloration was the fluctuating quality of water serving the area – a result of a mineral-laden ground water that exclusively had served northeast Fresno until 2004, and surface water processed through a treatment plant that became operational in 2004.

Snoeyink, nationally recognized for his research in environmental engineering and science, was enlisted by the city along with Marc Edwards, a professor of civil and environmental engineering at Virginia Tech who led a research team investigating the notorious situation of lead contamination throughout the municipal water system in Flint, Michigan, to assess Fresno’s efforts to deal with its water woes. The two have been working independently of one another.

Since January, complaints or reports of discolored water have been lodged with the city by as many as 1,000 or more residents in northeast Fresno – an area served by the city’s Surface Water Treatment Facility near Chestnut and Behymer avenues. But complaints about discoloration in the area’s date back to at least 2004, when the treatment plant became operational.

The problems appear to be related to the corrosion of galvanized pipes or lead-containing fixtures in homes in that part of the city, and what happens when a blend of water from the treatment plant and water pumped from wells flows through 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.

“Galvanized pipe is a big problem,” Snoeyink said. “It’s a poor choice for residential plumbing.”

In recent months, Fresno’s water division has been adjusting the water chemistry, including the amounts of corrosion-control chemicals with which canal water at the plant is treated. In March, the city also began adding corrosion-control chemicals to pumped groundwater.

That type of treatment, intended to stabilize corrosion and mineral scales on the interior of household pipes, will be key to reducing, if not eliminating, complaints of discolored water from residents, Snoeyink said. It is chief among a number of recommendations that he is making to the city, along with continuing to monitor the quality of the water, eliminating the use of galvanized pipe for plumbing in the future, and encouraging residents to replace older brass faucets in kitchens where households draw most of their drinking water. Faucets manufactured before 2010, Snoeyink said, contain about 8 percent lead and tend to release higher levels of lead into water. Since 2010, however, California has required kitchen faucets sold in the state to have much lower lead contents – about one-quarter of 1 percent – with much less lead released into water as a result.

Snoeyink added that unstable water chemistry in galvanized pipes can accelerate corrosion of the protective zinc layer on the inside of the iron pipes. As a result, water may show signs of iron and zinc, as well as lead that is part of the zinc used in the galvanizing process.

As the meeting wore on for more than three and a half hours, resident after resident asked city leaders what they were going to do about pipes they say have been damaged over the past 12 years of exposure to the water. And most came away frustrated by the lack of firm answers.

David and Mary Hutton said they moved into their northeast Fresno home just a few blocks from the water treatment plant in 1999, several years before the plant became operational. Even when the home was new, they had water quality issues. But those problems worsened, they said, after 2004 when the plant came online. “That’s when the rust started,” David Hutton said.

Hutton held out little hope for significant help from the city. “They’re going to play politics because they’re government people,” he said. “If they balance the pH, maybe that will balance the corrosion inhibitors where it won’t damage the pipes, but most everybody’s pipes are already damaged.”

Kassy Chauhan, an engineer with the drinking water division of the State Water Resources Control Board, said the city and state won’t be able to pin down how many homes have enduring corrosion problems in their pipes until after determining how successful the adjustments to water chemistry at the surface water plant are – and that’s something that may not be understood for months.

“I think there is pipe out there that’s going to have to be replaced” in some homes,” Chauhan said. “But we can’t get to that number” until the water chemistry work is concluded.

This story was originally published August 17, 2016 at 10:52 PM with the headline "Expert says better chemistry key to solving northeast Fresno water woes."