The number of northeast Fresno homes in which tests reveal lead in the water coming from faucets has climbed to almost 300, including nearly 120 in which lead levels exceed the acceptable threshold set by the U.S. Environmental Protection Agency.
A summary of lab results released Tuesday by the city’s Public Utilities Department reflects testing at 698 homes across northeast Fresno, out of between 1,500 and 1,600 in which residents have reported rust-tinged water since January. That is when one resident’s query on NextDoor, a social media website, triggered an outpouring of complaints from residents who previously thought their problem was unique to their home or a handful of neighbors.
Among the few common denominators among those residents is that their homes are plumbed with galvanized pipe, and they live in an area where at least some of their drinking water is provided by the city’s Northeast Surface Water Treatment Plant.
The discoloration complaints took on greater urgency earlier this year after testing revealed the presence of lead in the water coming from the taps in some homes.
Tuesday’s testing summary indicates that lead has been detected in at least one faucet in 119 homes at levels of 15 parts per billion or higher – the threshold set by the EPA at which a water agency must take corrective action. Another 167 homes are showing lead below the action level, while 412 showed no detectable levels of lead.
So far, of almost 2,000 fixtures that have been tested in those homes, 164 came in above the EPA’s action level for lead in initial testing. Those include 14 kitchen faucets used primarily for drinking and cooking, and 52 bathroom faucets used less frequently for drinking. “All of the others are faucets that aren’t regularly used or faucets that are not designed for human consumption,” said Mark Standriff, a spokesman for the city.
Subsequent testing has shown lead levels falling below the EPA action level in some faucets, leaving 10 kitchen sinks and 41 bathroom sinks above 15 parts per billion.
Earlier this summer, the city sent out mailers to about 22,000 residents in northeast Fresno – most in the 93710, 93720 and 93730 ZIP codes – as well as several thousand residents in northwest Fresno who don’t receive water from the treatment plant. Since that mailing, the number of homes reporting discolored water has leveled off, Standriff said. More than 92 percent of homes reporting discolored water are from the three ZIP codes.
City crews are collecting samples from about 15 to 20 homes a day to be sent off for laboratory testing, “so those results are going to continue to come in,” Standriff added.
Number up, percentage down
The city reported that while the raw number of homes with lead above the EPA action level has gone up since July, the percentage of homes above the threshold is slowly dropping, Standriff said. At the same time, some residents are reporting that while they’re still seeing discolored water coming from their faucets, it seems to be diminishing.
“That’s a direct result of not only the kind of tweaking of the chemistry”at the treatment plant, Standriff said, “but also the fact that we’ve added calcium carbonate, which is starting to coat those pipes on the inside and preventing that discoloration from coming out.”
A pair of leading national experts on plumbing corrosion have attributed the discoloration of water to the differences in chemistry and characteristics between surface water from the Enterprise Canal, which gets processed at the northeast treatment plant, and pumped groundwater that, until 2004, had been the sole source of drinking water for the city.
Civil engineering professors Vernon Snoeyink of the University of Illinois at Urbana-Champaign and Marc Edwards of Virginia Tech said the problems are 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. The changes in water source destabilizes rust and mineral scales that form on the inside of galvanized pipes in residents’ homes, resulting in discoloration from faucets. The water source in northeast Fresno is in constant flux between surface and groundwater, depending on the time of day and varying demand.
“Galvanized pipe is a big problem,” Snoeyink said at a community meeting in August. “It’s a poor choice for residential plumbing.” Yet it is believed that well over half of all of Fresno homes contain galvanized pipe.
Asking for patience
Snoeyink and Edwards added that lead in the water is most likely the result of water sitting stagnant in pipes and less-used, lead-bearing brass water fixtures in bathrooms, bathtubs, showers, laundry rooms and outdoor hose bibs.
Faucets manufactured before 2010 contain about 8 percent lead and tend to release higher levels of lead into water, Snoeyink said. But in 2010, California set a lead level of 0.25 percent for faucets sold in the state to be used for drinking and cooking.
For all the attention that water-discoloration reports have garnered since January, some residents report that they have complained to the city for years about poor water quality – some dating to 2004, the same year in which the treatment plant became operational.
“We know the hardest thing for anybody who’s been dealing with discolored water – and some of these folks for many years – is to tell them, ‘Please be patient.’ But we know we can engineer as best a solution as we possibly can over a three- to six-month period,” Standriff said.
“When we get to that point where we feel confident that we’ve done as much as we can to mitigate the discoloration, then we’ll deal with any homes left that still (have problems) because of the nature of their pipes or their fixtures, to try to solve the problems within their individual homes.”
Some residents, however, have lost patience, filing a potential class-action lawsuit on Friday alleging that the city’s mishandling of complaints for years has not only caused the premature corrosion of their galvanized plumbing, but also created a health hazard through exposure to toxic levels of lead in the water.