Though Chicago and other cities have long reported that lead levels in their water meet federal standards, regulators and scientists worry testing methods used for two decades could significantly underestimate consumers' exposure to the toxic metal.
Recent test results in Chicago may back up those fears: High lead levels were found in drinking water in seven of 38 Chicago homes tested by federal regulators this spring, according to records obtained by the Tribune.
"That's not really good news," said
, an environmental engineering professor at Virginia Tech who researches lead in water. The testing suggests lead in water could be a "significant human health concern," he said.
officials are still analyzing the tests, but
the results give credence to concerns voiced by advocates and scientists that lead could be an underestimated health risk in the nation's drinking water, especially in older cities and suburbs where lead pipe and solder are common.
The results also speak to concerns that utilities can "miss" lead when testing water by using certain permitted techniques, such as flushing pipes the night before samples are taken.
"People don't really know the extent of the problem," said Jeffrey Griffiths, a physician who is chairman of a drinking water advisory board for the EPA and a professor of public health and medicine at Tufts University School of Medicine.
Under federal law, local utilities must test water in a relatively small sample of homes. If lead concentrations exceed 15 parts per billion in more than 10 percent of water samples, the utilities must alert residents and try to lower levels. The city of Chicago hasn't exceeded the lead limit in nearly 20 years.
The allowable amount of lead was set in the 1990s and is based on a level utilities could feasibly meet. It is not a health-based standard, and many health and environment experts think the level allowed is too high.
Experts say there is no safe level of exposure to lead, which has been known to cause diminished IQs in children, even at low levels, and
and strokes in adults.
"What you really want is zero," Griffiths said. "Four (parts per billion) is better than 15, but four is still four."
Water rarely contains lead when it leaves treatment plants, but the heavy metal can leach into water while it sits in or flows through service lines that connect water mains to homes. Pipes and faucets inside homes also can contain lead, as can solder and brass parts used with plumbing materials.
Lead in water doesn't smell or taste strange, so consumers would likely be alerted to the problem only if they have their water tested or if regulators discover the problem.
To prevent leaching, treatment plants add orthophosphate and other chemicals to water. A chemical reaction causes a white coating to form on the inside of pipes that is meant to stop lead from leaching into the water, but it isn't always effective.
Water treatment is also complicated. For orthophosphate to protect against lead, the pH of water needs to be within a certain range. But if pH is too high in some water systems, calcium can build up, making valves like those on fire hydrants hard to open.
"You are kind of doing a balancing act," said Miguel Del Toral, regulations manager for EPA Region 5's Groundwater and Drinking Branch. "It's not as simple as just make one change and you are fine."
If high lead levels persist, a utility may have to replace lead service lines, although recent studies show partial pipe replacements can actually contribute to spikes in lead levels because they disturb lead rust that breaks off or leaches at a higher rate.
, 52 water systems have been found to have high lead levels since 2008, according to a Tribune analysis of state records. Last November,
alerted residents after 14 percent of samples contained elevated lead levels.
Although the majority of water systems report that homes they test meet federal regulations, some experts think those results are due to outdated testing, government agencies gaming the system, or both.
"You can meet the federal standard, according to the letter of the law, but that doesn't mean that a large fraction of homes in your system aren't being exposed to levels of lead that are a public health concern," Edwards said.
found that residents in Washington and the surrounding area had been exposed to unsafe levels of lead in water for at least a year. Edwards and congressional committees helped document the extent of the lead problem and detailed how it had been covered up for years.
Among other methods for influencing lead testing results, instructions were given to homeowners and schools to flush water lines the night before testing, a practice that could clear out lead particles in the water. Homeowners also were instructed to open taps "slowly" or "gently," resulting in slow water flow that might prevent lead particles from coming out.
In response to the lead problems and flaws with testing, the EPA in 2004 began a sweeping review of what is known as the Lead and Copper Rule, which passed in 1991 and requires water systems to test homes for those metals.
The review turned up various issues, including that utilities in Chicago and other cities were instructing residents to remove the aerator from their faucet and clear out any debris before testing water. That would remove small pieces of lead that could end up in drinking water with normal use. The EPA told utilities in 2006 to stop telling homeowners to clean off aerators.
questions remain about whether current testing protocol accurately gauges homeowners' exposure to lead.
In Chicago and other cities, homeowners are instructed to run cold water from their faucets for five minutes, then leave the tap off for six hours before testing. The goal is to flush hot water from the plumbing, as hot water is thought to dissolve more lead into water.
The water that is sampled is the first liter to come out of the faucet, or water that has been held in the home's pipes. A different sample would be needed to screen for lead in water that had been sitting in the service lines outside the home.
The EPA decided to test homes in Chicago after realizing the agency didn't have any data that scrutinized multiple ways to test for lead, said Del Toral, the regulations manager.
The agency is now doing three rounds of testing in homes of federal employees. Chicago's Department of Water Management is working with the EPA to do similar testing in the 50 homes it tests every three years. City officials would not release the most recent testing results to the Tribune, saying the information is being studied.
Del Toral said testing for lead is difficult because concentrations can vary significantly based on water usage, pipe material and time of day, as well as other factors. Isolating the source of lead is hard too — did it come from inside the home, a faucet or the service lines outside a home?
In the most recent tests, the EPA took multiple samples at each home using different testing methods. The results varied widely. One home, for example, had two tests come in at five and three parts per billion and two tests at 25 and 22 parts per billion. The EPA declined to discuss the methods it used or where the homes are located.
The agency said it is awaiting results from a second round of tests to help isolate why levels in some homes were high. A final round of testing will be done in September.
The Tribune has tried since May to obtain the results of the EPA's testing. In June the agency's Region 5 denied the newspaper's request under the Freedom of Information Act, but that decision was overturned in late July by the agency's headquarters in Washington.
This spring, the Tribune tested water for lead in 46 homes in Chicago, using a method similar to that used by the city of Chicago. The Tribune also had homeowners let their faucets run for 45 seconds before collecting a second sample of cold water. No homes were found to have water with lead levels above 15 parts per billion, although two came close with
14.9 and 13.1 parts per billion.
Griffiths, the physician at Tufts, said he would buy a filtration system if his water tested that high, even though it is still below the EPA's "action level."
"I wouldn't drink the water," he said.
Jennifer Kelly lives in the
home where the water tested at 13.1 parts per billion. Kelly, a nurse, and her husband, Liam, have three young children.
"It's always in the back of my mind," Jennifer Kelly said. "It concerns me a lot. I don't see any deficits with (the kids) but you just never know."
Tips for reducing exposure to lead
The Chicago water department will test residents' water for lead at no charge. Residents can call 311 for information. Others can call the Safe Drinking Water Hotline, 800-426-4791, to find out how to contact a laboratory. That testing costs $20 to $50.
Some ways to reduce exposure to lead in water:
•Use only cold water for drinking, cooking and making baby formula. Hot water likely contains more lead.
•Occasionally clean and remove the strainer or aerator on faucets. Particles can become caught there.
•Make sure new faucets and other plumbing fixtures meet lead-leaching standards.
•Flush the pipes. The longer water sits, the more lead it may contain. It can take 3-5 minutes to completely flush pipes if water hasn't been heavily used through showering, laundry or dishwashing.
•After heavy use, run the tap for 30-45 seconds to clear lines.
•Some instruments can filter out lead. NSF International and the Water Quality Association provide a list of certified devices. Search for specific products and what they filter out at