New evidence suggests that the way US water is tested for lead is vulnerable to conflicts of interest that raise questions about data confirming tap water’s safety. The new evidence could cast further doubt on already controversial testing methods highlighted following the ongoing water crisis in Flint, Michigan.

A Guardian investigation has discovered that in the US’s third most populous city the testing regime for lead involves using its own employees’ homes.

“This does raise significant concerns about a conflict of interest,” said Marc Edwards, the Virginia Tech scientist and MacArthur Genius Award winner who helped expose the ongoing crisis in Flint.

The Guardian’s analysis of records from the city of Chicago’s water management department, which serves 5.4 million residents, reveals that of the 51 homes analyzed for lead contamination in the city in the last round of testing, at least two dozen were the agency’s own current employees. Past tests in the city have allowed senior water department staff and retirees of the department to provide water samples which allow the city to pass regulatory muster with the US Environmental Protection Agency.

“It has also been a long-term mystery why the Chicago water department has never found problems with high lead in Chicago water,” said Edwards, “when outside entities including the US Environmental Protection Agency and Consumer Reports have repeatedly done so.”

The city already faces criticism for not warning residents about the potential for increased lead exposure in water as service lines are partially replaced, as part of the city’s “Building a New Chicago” program.

From 2003 to 2015, 40 of the 59 people identified in the city’s water testing scheme appear to be current or former city employees, according to employment and pension records and in one case a lawsuit against the city. Residents at another 45 testing sites were not identified by name by the city.

In the same 12 years, a Guardian analysis found at least 15 of the sites tested appear to be the homes of Chicago water management employees, including senior engineers, plumbing inspectors, and even the former deputy commissioner of the Bureau of Water Supply, John F Spatz. The water department later told the Guardian that the latest round of water sampling included 24 residences of employees, of the total 51 sites sampled.

The city of Chicago is required by the US EPA to test what are deemed the “highest risk” homes based on a variety of factors such as whether the homes have lead services lines and the year the homes were built.

The water department maintains that these are the highest risk homes in the city.

But Edwards is skeptical. “It seems hard to believe, that these employee homes are the ‘worst case’ sampling sites that are supposed to be targeted,” he said.

The city’s water management department serves about 5.4 million residents, but is only required to test 50 sites every three years for lead and copper contamination, according to the Illinois EPA. Chicago is reported to have as many as 400,000 lead service lines, and up to 80% of the lines that bring water to homes are reported to be lead. Installing lead lines was standard in the city until 1986, when the practice was stopped nationally.

Testing lead levels in water is required by the US Environmental Protection Agency. In Chicago, EPA Region 5 oversees the city’s water, the same EPA district that oversaw Flint’s water. The head of that EPA Region, Susan Hedman, resigned in January in connection with the crisis in Flint, where a lack of water treatment resulted in months of extraordinarily high lead levels in tap water.



A water management spokesman, Gary Litherland, told the Guardian that Chicago asked its own employees to test their water because: “It was easier to train your own personnel than bring in people, because you’re basically asking somebody to sit and not use their water overnight, and that sounds real easy in the beginning until you actually try to do it.”

He said “about 50%” of the homes tested belonged to employees of the water management department.

“So we do use our employees, and the other reason is because in Chicago, if you work for the city of Chicago you have to live in the city of Chicago which means you’re kind of committed to staying here, which is the other reason we like it. Because it provides us with better long-term data,” said Litherland.



In fact, a letter sent by the current deputy commissioner of the Bureau of Water Supply, Alan E Stark, in September 2015, said that new volunteers were needed that year, “due to [several] moving and passing away”.

Testing employees’ water is so embedded in the city of Chicago’s protocols that the city has developed two separate sets of instructions for sampling water: one for city employees and one for the general public.

Instructions for employees at the Jardine and South water purification plants ask them to sign a form and bring the bottle to the water management department’s water quality surveillance section.

“Set the bottle on top of the cabinet in a box marked lead and copper samples inside of doorway,” employees are told.

Lead contamination in water has received increased public attention since it became apparent that regulators in Flint, Michigan, knew the midwestern city’s water was contaminated with lead, but did little to remedy the situation. In one case, a Flint woman’s tap water had 47 times the legal limit of lead contamination.

Lead is a neurotoxin in children and can adversely affect adults’ ability to have children. The Centers for Disease Control and Prevention has repeatedly warned there is no safe lead level.

Over the past several years, Mayor Rahm Emanuel’s administration and the city’s water department have faced multiple rounds of scrutiny.

A 2013 study of 32 homes in Chicago published in the journal Environmental Science and Technology found that the EPA’s own Lead and Copper Rule sampling protocol “systematically misses the high lead levels and potential human exposure”.

The study’s lead author, Miguel Del Toral, is the same EPA water expert who attempted to blow the whistle on Flint’s tainted water months before the crisis became public.

He wrote that when sequential water samples were taken from homes, they found “maximum [lead] values more than four times higher than Chicago’s regulatory compliance results using a first-draw sampling protocol”.

The study warned that lead levels appeared highest at homes where lead lines were disturbed, through street-heavy excavation or even relatively minor meter replacement.

After Del Toral’s report, however, the Chicago’s political establishment attempted to sideline the scientist.

“Chicago water is absolutely safe to drink and meets or exceeds all standards set by the US Environmental Protection Agency and the Illinois EPA,” wrote the water commissioner, Tom Powers. “The data cited by the media is very meager and much more study is needed to draw any meaningful conclusions.”

Already, the water department had quietly removed controversial instructions for how employees and residents were told to sample water, according to documents provided to the Guardian.

Water sampling instructions from 2006 and 2009 asked people to remove faucet aerators, “clean out any debris, flush for five minutes with cold water and replace the aerator”.

Such measures are regularly criticized by water experts such as Marc Edwards, who runs the Flint Water Project, testing residents’ homes for lead levels, and who first found that Washington DC had severely elevated lead levels in water in 2003.

Removing the faucet’s aerator and “pre-flushing”, as regulators call the procedure, go against the spirit of the monitoring, the EPA and clean water activists have said. As early as 2006, the EPA issued a memo calling such procedures “against the intent of the monitoring protocol”.

“If customers are only encouraged to remove and clean aerators prior to drawing a sample test for lead, the public water system could fail to identify the typically available lead contribution from that tap, and thus fail to take additional actions needed to reduce lead exposure in drinking water.”

The February 2015 notice from the city of Chicago seemed to recognize that cleaning aerators can affect the amount of lead in water. The notice, sent out as the city replaced water mains, told residents to clean aerators because, “metals can collect in the aerator screen located at the tip of your faucets”.

The city’s most recent consumer confidence report, a federal requirement, found 6.6 parts per billion of lead or lower in 90% of homes testing. That is below the federal limit of 15 parts per billion.

On Thursday, the Chicago law firm Hagens Berman filed a class action lawsuit against the city, claiming it failed to properly notify residents about the potential for increased lead exposure as water mains were replaced as part of the “Building a New Chicago” program.



Additional reporting by Oliver Milman in New York

• This article was amended on 11 April 2016. An earlier version said a Chicago consumer confidence report found 6.6 parts per billion of lead in 90% of homes tested. That has been amended to say that 90% of homes had 6.6 parts per billion or lower.