One of the nation’s leading experts in corrosion problems in public water supplies said that despite considerable concern over discoloration of water coming from galvanized pipes in a growing number of northeast Fresno homes, “at present there’s really no indication at all that there’s a lead problem” in the city’s water under federal law.
Marc Edwards, a professor of civil and environmental engineering at Virginia Tech, has been enlisted by Fresno to help design an improved strategy of corrosion control to reduce complaints from residents over red-tinted water as rust and other scales are shed from the galvanized iron pipes in their homes. Edwards leads a research team that studies water systems across the country, including a broad investigation of the widespread lead contamination in the municipal water system in Flint, Mich.
While the toxicity of lead is well documented, Edwards discounted comparisons characterizing Fresno’s water problems as “another Flint” based on fears about lead contamination. But, he added, the widespread use of galvanized pipe for decades to plumb homes in Fresno — and the chemical characteristics of pumped groundwater that was extraordinarily gentle on those pipes — essentially set the city up for red-water problems once treated surface water from the Enterprise Canal was introduced into the water supply in northeast Fresno.
“Having red water is just inherent to having galvanized iron, just maybe not at the levels currently being experienced in some parts of Fresno,” Edwards said. “But people can and do live with those problems all around the United States.”
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As he discussed the distinction between discolored water and lead contamination, Edwards pointed to data from water samples at hundreds of northeast Fresno homes since January. That’s when social media posts triggered a firestorm of complaints to the city from residents about red-, brown- or yellow-tinged water in their homes.
Since the start of this year and through the first week of August, more than 1,500 residents have registered complaints or requested testing of their water. The city reported that of the 376 homes for which test results had come back, encompassing 1,136 individual faucets or taps, 94 fixtures in 64 homes showed levels of lead above 15 parts per billion, the U.S. Environmental Protection Agency’s threshold to require corrective action.
But Edwards and Vernon Snoeyink, another prominent water-supply expert, said that kitchen-sink faucets are the most important ones under the EPA’s Lead and Copper Rule because those are the ones used most often for drinking water and cooking. In fact, Edwards said, cold-water kitchen taps and cold-water bathroom taps are the only ones counted for official sampling under the EPA’s testing protocol. And as of early August, both experts said, only four kitchen faucets were showing test results with lead levels above the EPA threshold.
“In Fresno, of the few houses that had high lead, many of (the samples) were coming from taps other than the kitchen or bathroom faucet,” Edwards said. “These sample locations are not valid for determining compliance (with the EPA rule) because … in the time they were manufactured, those fixtures were not designed to dispense water fit for human consumption because they tend to have higher lead in them.”
The health threat from lead pipe in Flint
Marc Edwards, professor of civil and environmental engineering at Virginia Tech
As a result, samples from bathtubs, showers, utility rooms, hose bibs and other less-used faucets “are specifically excluded and should not be counted as an EPA sample,” he said. While high lead levels at those non-kitchen fixtures are doubtless worrisome to residents, “it’s very important to realize that there’s no danger of exposure in showering or bathing in water that has lead in it,” Edwards added. “It doesn’t absorb through the skin, you do not breathe a significant quantity of water droplets into your lungs” from a shower.
Edwards said he concurs with official guidance from the EPA and the national Centers for Disease Control and Prevention that “this does not pose a threat to people who want to take baths or showers, whether children or adults. It’s not an issue.”
The key difference between Flint’s well-publicized troubles and what is happening in Fresno is the widespread use of lead pipes in Flint, “and there’s no evidence there’s any lead pipes in Fresno,” Edwards said.
“The health threat from lead pipe in Flint vs. galvanized iron pipe is at least 100 times higher,” Edwards said. “Take the lead pipe out of the equation, and you don’t have nearly the same problem (in Fresno). It’s two orders of magnitude lower to start with.”
He added that while Fresno has been treating its water to prevent lead and copper corrosion, “Flint obviously had no corrosion control program at all.”
‘Fixing’ the water
The uproar about discolored water in northeast Fresno exploded in January, after neighborhood resident Jeanette Grider posted on the NextDoor social media website asking if any other residents were having problems with their water.
That’s when many more people realized that their problems were not unique to their homes. But scattered complaints about water quality date to at least 2004, when the city’s northeast Surface Water Treatment Plant became operational, as people reported instances of discoloration to the city’s water department.
“What we’re talking about here is a situation where you historically had a very noncorrosive groundwater source,” Edwards said. “The new surface water that was brought online was not being treated in a manner that could control … galvanized iron corrosion.”
The change in the character of the water — hardness, pH, alkalinity, temperature and other factors — tended to disrupt an otherwise stable layer of rust that accumulated in the pipes inside of homes over decades, enabling the red stuff to flake off or dissolve in the water and flow from faucets.
“There is no law that focuses a utility’s attention on minimizing galvanized iron corrosion … . If you had to pick a corrosion problem, you would much prefer a galvanized iron problem than a lead problem or copper problem,” Edwards said. “That’s the law: Thou shalt optimize corrosion control for lead and copper.” He added that the city has treated the water appropriately under that law over the years.
But, he said, “the water utility does have a responsibility, because they’re choosing to take it on beyond the requirements of the law … to treat that water in such a way that it reduces the red-water complaints, reduces the discoloration and extends the life of that galvanized iron infrastructure for as long as possible.”
Edwards agreed with Snoeyink — a professor emeritus in the civil and environmental engineering department at the University of Illinois at Urbana-Champaign — that better water chemistry will be crucial to reducing the discoloration problems that are plaguing northeast Fresno and preventing a repeat of the problems in a couple of years when the city opens a second, and much larger, surface water treatment plant in southeast Fresno.
Snoeyink, who is working with the city but independently from Edwards, is nationally recognized for his research in environmental engineering and science concerning municipal water systems.
He said last week 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 traces of lead that is part of the zinc used in the galvanizing process.
Galvanized pipe is a big problem. It’s a poor choice for residential plumbing.
Vernon Snoeyink, professor emeritus of civil and environmental engineering, University of Illinois at Urbana-Champaign
Both experts suggested that even with exemplary water treatment, however, northeast Fresno likely won’t be completely rid of red-water complaints as long as there are galvanized pipes in homes and businesses.
“Galvanized pipe is a big problem,” Snoeyink said. “It’s a poor choice for residential plumbing.”
Among Snoeyink’s recommendations to the city are: taking immediate steps to stabilize the chemical characteristics of the water in the city’s mains in northeast Fresno; continued monitoring of water quality and customer complaints; continuing studies to optimize corrosion-control treatments; encouraging residents to switch out older brass kitchen faucets containing higher levels of lead with newer, low-lead fixtures; and “moving toward a galvanized-free future.”
On Thursday, the Fresno City Council adopted a ban on the use of galvanized pipe in all new residential and commercial construction as well as for major remodeling projects.
“Galvanized pipe is sort of doomed in the marketplace, and with good reason: It does not perform well in modern water supplies,” Edwards said. “If you have galvanized pipes and the water sits there for a period of time, across the United States you can pretty much be guaranteed that red water is going to come out of the tap.”
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