Chicago spent the past decade tearing up streets to replace aging, sometimes leaky water mains, borrowing more than $400 million and doubling the cost of water to pay for the work.

On every one of the 792 miles dug up, crews hired by the Department of Water Management connected new cast-iron water mains to old lead pipes known as service lines that bring water into single-family homes and two-flats.

The department continued this routine even after a 2013 federal study of Chicago homes found it can expose people to alarming concentrations of lead, a brain-damaging metal with no safe level of exposure.

Now, with fewer than 90 miles of water mains still to be replaced, state law is forcing city workers and contractors for the first time to pull out toxic pipes at the same time.

Starting last week on the 3100 block of South Ridgeway Avenue in Little Village, crews are going house by house reconnecting Chicagoans to the municipal water system with safer copper pipes.

The project marks the beginning of a more concerted effort to rid the nation’s third largest city of roughly 400,000 lead service lines, which Chicago required by law until the end of 1986, decades after most other cities banned use of the toxic metal to convey drinking water.

“We are happy they are finally beginning to address this problem, though it’s taken them far too long,” said Kim Wasserman, executive director of the Little Village Environmental Justice Organization.

Four years ago, Mayor Lori Lightfoot promised during her first campaign to begin addressing a health threat her predecessors insisted didn’t exist. By the end of March only 451 lead service lines had been replaced in low-income households that qualified for a share of federal grant money.

[ Mayor Lori Lightfoot set a goal to replace 650 toxic lead pipes in Chicago in 2021. So far, 3 have been removed. ]

Another 306 were replaced during responses to leaky pipes and 110 were paid for by individual property owners, according to water department records.

For a number of reasons, the pace of replacements is about to speed up not only in Chicago but statewide.

A 2021 state law requires small Illinois water utilities to replace all lead service lines within 15 years. Larger systems get up to 34 years to complete the work. Another provision of the law demands that service lines must be replaced whenever a new water main is installed.

Lightfoot’s lobbyists in Springfield blocked the law from passing until state legislators agreed to give Chicago up to 50 years to finish the job. At the mayor’s behest, lawmakers also exempted the city from the water main provision until January.

Mayor-elect Brandon Johnson pledged during his campaign to make lead service line replacements a priority. In March, he noted on Twitter that the majority of childhood lead poisoning cases in the city are in predominantly Black and Latino neighborhoods. “That ends with a Johnson administration — because water is life,” he wrote.

More money to pay for the work is on the way. Chicago is bound to get a cut of the $3 billion Congress set aside last year for lead service line replacements — fulfilling a campaign promise by President Joe Biden. The city also is borrowing another $336 million through a low-interest federal loan program for water projects.

“Chicago’s own monitoring shows the city has a big problem with lead in water,” said Erik Olson, a senior strategist at the nonprofit Natural Resources Defense Council who for decades has clamored for a more aggressive response from federal, state and local governments. “What you need is somebody who actually wants to fix it, who steps up to the plate and asks ‘What are the impediments and how do we get rid of them.’ ”

Newark, New Jersey, highlights what can happen when city leaders stop denying they have lead-in-water problems and get to work eliminating them.

After he was criticized for his initial response to testing that found high lead levels in Newark schools and homes, Mayor Ras Baraka persuaded New Jersey lawmakers to clear the way for local ordinances that eliminated the need for a property owner’s permission to replace a lead service line — a critical change that helped get the lead out in rental properties.

City officials declared a health emergency and agreed to pay to replace about 23,000 lead service lines rather than requiring property owners to contribute or making them fill out paperwork proving they couldn’t afford the work.

Baraka also negotiated deals with trade unions to train local people for a project that was expected to take a decade to complete but was all but done in less than three years. Crews fanned out across the city, replacing up to 120 service lines a day at one point, said Kareem Adeem, director of Newark’s water and sewer department.

“We’ve shown how to get this done because we had the political will to do it,” Adeem said in an interview. “That’s what every city needs: political will.”

In Chicago, water department spokeswoman Megan Vidis declined to make Commissioner Andrea Cheng available for comment. The department has hired and trained more people to replace service lines and is seeking funding for a “multi-year, multi-billion dollar effort,” Vidis said in an email.

Ingesting even tiny concentrations of lead can permanently damage the developing brains of children and contribute to heart disease, kidney failure and other health problems later in life. In 2018, researchers estimated more than 400,000 deaths a year in the United States are linked to lead exposure.

Like many other cities, Chicago, adds corrosion-fighting chemicals to the water supply that, in theory, form a protective coating inside lead pipes to prevent leaching.

But the water department acknowledges that lead-contaminated water can still flow out of faucets, especially if people haven’t taken a shower, done laundry or washed dishes for several hours. Studies in Chicago and other cities also have found high concentrations of the toxic metal can flow out of taps for weeks or even months after lead service lines have been jostled by street work or plumbing repairs, including water main replacements.

A 2018 Chicago Tribune analysis found that lead in tap water is a danger throughout Illinois.

More than 8 of every 10 Illinoisans live in a community where the toxic metal was detected in at least one home during the previous six years, the newspaper found. Dozens of homes had hundreds and even thousands of parts per billion of lead in tap water — just as extreme as what researchers found during the same period in Flint, Michigan, where mismanagement of the public water system drew a world spotlight to a scourge that remained largely hidden for decades.

[ Brain-damaging lead found in tap water from most Illinois communities during the past 6 years, Tribune analysis finds ]

Last year alone lead was detected in water from at least one home in more than 60% of the Illinois water systems tested, state records show. Several results were significantly higher than 5 parts per billion, the Food and Drug Administration’s limit for bottled water.

Lockport found one home with 1,610 ppb of lead in tap water, records show. Rockford detected 800 ppb of lead in a home. Evanston found 250 ppb of lead in one of its samples.

If what is happening on Ridgeway Avenue is any guide, Chicago is still facing a number of hurdles to get lead out of tap water.

On Thursday one woman refused to allow workers into her home and rebuffed pleas from Ald. Michael Rodriguez, 22nd, to see for herself how the first lead service line on the block had been replaced without digging up her neighbor’s yard. One of the workers said several other property owners on the block are “tired of seeing guys in suits” knocking on their doors asking for permission to install a copper water line.

Water department contractors are reducing the impact of lead service line replacements by using a boring machine that only requires digging up a portion of the street. The machine removes the lead pipe first, then unwinds a coil of copper pipe from a home’s basement before plumbers attach it to the water main.

As Carmen Gonzalez looked down from her porch at her soon-to-be buried copper water line, she said she was relieved the work was almost done.

“I’ve been drinking the water in Chicago for many years,” said Gonzalez, who moved to the city in 1972. “But then my children said the water might not be safe, and I started drinking bottled water. Now I won’t need to do that any more.”

mhawthorne@chicagotribune.com