Local

Fresno bans galvanized pipes as response to northeast’s tainted water

Vernon Snoeyink, a professor of civil and environmental engineering, discusses galvanized pipe corrosion and Fresno’s water treatment at a meeting that attracted about 500 northeast Fresno residents on Wednesday.
Vernon Snoeyink, a professor of civil and environmental engineering, discusses galvanized pipe corrosion and Fresno’s water treatment at a meeting that attracted about 500 northeast Fresno residents on Wednesday. tsheehan@fresnobee.com

Fresno will join several other major California cities to ban the use of galvanized pipe for plumbing in new residential and commercial construction and major renovation work.

At its meeting Thursday afternoon, the Fresno City Council formally adopted changes to its building ordinance that prohibit the zinc-coated metal pipes. Fresno City Councilman Lee Brand originally introduced the ban July 28. After Thursday’s 6-0 vote, the new rules will take effect in a month.

The ban is part of the city’s response to problems at a growing number of homes in northeast Fresno reporting discoloration – and in some homes, toxic lead – in the water coming from corroded galvanized pipes. The homes are in the area of the city served by canal water processed by the city’s Northeast Surface Water Treatment plant.

It’s also among the recommendations outlined this week by a noted national expert being consulted by the city on corrosion issues and water treatment at the northeast plant.

I think we’ve made the right choice based on all the trauma and ordeal we’re going through now with the northeast water. It’s clear we never want to repeat that again.

Fresno City Councilman Lee Brand, who represents District 6 (northeast Fresno)

Most contractors have already made the switch from galvanized pipe to materials such as PVC and PEX piping for plumbing in new construction. But the ban takes galvanized pipes completely off the table as an option for builders and plumbing contractors.

“I’ve talked to plumbers who still use galvanized pipes. Other cities have banned it, and it’s obvious there’s a problem,” Brand said Thursday. “So I think we’ve made the right choice based on all the trauma and ordeal we’re going through now with the northeast water. It’s clear we never want to repeat that again.”

Among other California cities to ban galvanized pipe are Santa Clara, San Diego and Irvine, according to the ordinance.

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, Mich., is helping assess Fresno’s efforts to deal with its water woes. He told reporters Thursday that Fresno for decades has benefited from pumped ground water that he described as “extremely noncorrosive” to galvanized pipe. That’s different from many other water systems where the water does not interact well with galvanized pipe – and is a key reason why galvanized is increasingly out of favor as a plumbing material for construction.

But, he added, “at this point, there is really no indication at all that there’s a lead problem in Fresno” under the U.S. Environmental Protection Agency’s lead and copper rule.

The increased number of complaints about discolored water in Fresno, Edwards said, “is likely going to be experienced by many utilities (in California) as they switch increasingly to surface water.” The discoloration, he added, “is normal for the rest of the U.S. but more than what Fresno is used to.”

Vernon Snoeyink, a professor emeritus in the civil and environmental engineering department at the University of Illinois at Urbana-Champaign, is the other expert being called on to help the city. At a community meeting Wednesday night that drew about 500 residents to Clovis West High School, Snoeyink 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 in the neighborhood’s galvanized pipes was the fluctuating quality of water serving the area – a result of a mineral-laden groundwater that exclusively had served northeast Fresno until 2004, and surface water processed through the treatment plant that became operational in 2004.

Snoeyink, nationally recognized for his research in environmental engineering and science, is working independently of Edwards.

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 water date back to at least 2004, when the treatment plant became operational.

Galvanized pipe is a big problem.

Vernon Snoeyink, professor emeritus of civil and environmental engineering from the University of Illinois at Urbana-Champaign

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 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.

Water concerns

Since January, residents of 1,531 homes in northeast Fresno have lodged reports, complaints or concerns about discolored water coming from their faucets or asked for their water to be tested. The city is continuing to run tests on water samples from those homes.

Number of homes

As of July 1

As of July 8

As of July 26

As of Aug. 8

Sampled for lead in water

220

241

279

376

Showing lead above 15 ppb *

43

45

51

64 **

Showing lead below 15 ppb

52

59

70

86

Showing no detectable lead

125

137

158

225

* 15 ppb = 15 parts per billion of lead in the water is the U.S. Environmental Protection Agency’s threshold requiring mandatory corrective action

** 12 homes have tested below the EPA action level in subsequent retesting

Data source: City of Fresno, Department of Public Utilities

Reporting a problem?

Residents with discolored water or who are concerned about possible lead contamination in their water can report problems to Fresno’s water division or request testing by:

▪ Using the city’s FresGO mobile app on Apple or Android smartphones or online at http://bit.ly/NE-water

▪ Calling the water division at 559-621-8626

▪ Sending an email to RequestWaterTest@fresno.gov

  Comments