More than 40 homes scattered across northeast Fresno are testing positive for lead above acceptable levels as the city continues to try to figure out what is causing corrosion of galvanized water pipes in residences.
The latest update comes after the city expanded its investigation, sending notices to more than 45,000 water customers across six ZIP codes in the northern areas of Fresno – including about 15,000 homes in the 93720 and 93730 ZIP codes where the bulk of complaints from residents about discolored water have originated. Since January, hundreds of homes in northeastern Fresno have reported various levels of discoloration in the water coming from their faucets and are being tested for metals, including lead.
In June, the city reported that about 35 homes had tested positive for lead at levels above 15 parts per billion, the point set by the U.S. Environmental Protection Agency as the threshold requiring corrective action.
As more homes report discolored water – and as Fresno’s water division makes incremental adjustments to the chemical treatment of canal water and pumped well water – the number of lead-positive homes has fluctuated.
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A total of 51 homes have tested above the EPA action level since testing began, but retesting after adjustments to the water chemistry have reduced the lead levels to below the action level or to non-detectable levels in 10 of those homes.
Through July 26, the city has tested the water at nearly 280 homes, taking samples from almost 840 individual faucets or fixtures. Of those homes, 158 showed no detectable lead at any faucet, while another 70 reported lead concentrations below the EPA action level in initial testing.
Our goal is to continue to reduce the number of homes reporting lead concentrations at indoor plumbing fixtures that are used to draw water for cooking and drinking.
Thomas Esqueda, Fresno public utilities director
“We fully expect the numbers to continue to fluctuate as homes are tested and retested,” said Thomas Esqueda, the city’s public utilities director. “Our goal is to continue to reduce the number of homes reporting lead concentrations at indoor plumbing fixtures that are used to draw water for cooking and drinking.”
Currently, only four of the fixtures testing positive for lead above the EPA level are at kitchen sinks, Esqueda added.
The expanded notification also has driven up the number of homes reporting discoloration, either through an online survey, email or a dedicated phone number. As of July 26, nearly 800 residents used the online survey to report discoloration in at least one faucet in their home. All but nine came from the 93710, 93720 and 93730 ZIP codes.
More than 650 calls came in through the phone line, and 328 reports were filed by email. Some residents, however, used two or three of the different methods to report problems, and Esqueda said his staff is working through all the responses to eliminate duplicate reports and to arrange for testing.
“We are averaging 15 to 20 homes per day for sampling,” Esqueda said. The testing requires that no water be used by the residents in the home for at least six hours before sampling, and most of the first-draw sampling is scheduled between 4 and 7 a.m., he added.
The investigation is trying to determine what is causing the discoloration and contamination, which largely appears to be related to corrosion of galvanized iron pipes or lead-containing fixtures within homes in the area served by the city’s Northeast Surface Water Treatment Facility.
Surface water from the Enterprise Canal is disinfected and treated at the plant. There, corrosion-control chemicals are added to the water and it is blended with pumped well water for distribution in the city’s drinking-water mains to homes and businesses throughout the northeastern part of the city.
The treatment plant became operational in 2004 – about when some of the earliest reports of discoloration problems arose from residents in the area. At that time, however, the city treated those as isolated cases, and no serious action began until January, when the scale of the problem became apparent through social media postings by residents.
There’s no coincidence in the fact that when the surface water (plant) came online, the problem started developing.
Lee Brand, Fresno City Councilman for District 6
Fresno’s water division, as well as the State Water Resources Control Board, maintains that what gets delivered to homes in the city’s distribution 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.
Fresno City Councilman Lee Brand, whose district covers northeastern Fresno, said last week that he believes “there’s no coincidence in the fact that when the surface water (plant) came online, the problem started developing” with residents’ galvanized pipes.
Surface water has a different temperature, and chemical and pH characteristics than water pumped from wells and distributed for decades through the city’s system. Those different characteristics can degrade protective mineral scales that form over time on the inside of pipes and allow for corrosion to happen faster.
The city believes an influx in lower-grade galvanized pipe from Asian manufacturers during the late 1980s and through the 1990s, when many of the homes reporting discoloration were built, is also part of the problem.
“It appears to me, and I’m no expert, that the city played a contributory role in what happened,” Brand said. “Now there’s no question the galvanized pipe was a major factor. … If the water was right, would the galvanized pipe eventually fail? Probably, but did this accelerate it by two years, five years or 10 years? We don’t know.”
Had the city undertaken this type of investigation back in 2004, when some of the earliest reports from residents came in, “a lot of the problem would have been solved,” Brand added.