Over 1,300 US Water Systems Miss Lead Pipe Inventory Deadline

More than 1,300 public water systems across the United States have been cited by the Environmental Protection Agency for failing to submit an inventory of their water service lines by an October 2024 deadline, according to an analysis of federal enforcement data. Roughly 6,300 systems serving about 3.8 million people have yet to file the required lists showing how many lead service lines remain in use.

The inventories are a prerequisite for a broader effort to replace all lead pipes within a decade. Without them, utilities cannot plan replacements, and residents cannot know whether the pipe connecting their home to the mains is a potential source of lead exposure.

In Dunkirk, New York, homeowner Kathryn Pilgrim replaced suspect plumbing and installed a kitchen filter after buying a century-old house, but still cannot confirm whether the underground line linking her property to the city supply contains lead. Dunkirk, which serves about 5,000 homes and businesses, is nearly two years behind on its inventory. City officials did not respond to requests for comment.

Lead service lines remain the most significant source of the neurotoxin in drinking water, the EPA says. How much leaches into a building depends on water chemistry and pipe condition. Lead can impair children's development, lower IQ scores and raise blood pressure in adults. The agency estimates about 4 million homes and businesses are still connected through lead pipes.

Most of the systems with missing inventories are small: 84% serve fewer than 500 people, and many are housing developments, mobile home parks or schools. About 3,500 systems reported they do not know what their lines are made of, and one in five service lines nationwide was listed as having unknown material.

The EPA said it resorted to enforcement only after efforts to help utilities comply failed. The inventories feed into a 2027 requirement that most drinking water providers replace their lead lines within 10 years — a deadline enacted under the Biden administration that the Trump administration has defended in court. About three-quarters of the agency's drinking water enforcement orders since President Donald Trump returned to office concerned missing inventories.

Rob Hayes of Environmental Advocates of New York called the lead rule a rare environmental regulation the current administration has not sought to dismantle, pointing to broad public support for removing lead from drinking water.

Utilities are now racing to identify unknown pipes before replacements must begin. In Chicago, which has more lead lines than any other US city, crews are working block by block. Patrick Schwer, the city's water quality director, said close to one in 10 service lines still has an unknown material, meaning some may have to be excavated. He said the city is sifting through millions of work orders for clues and pursuing every available federal and state dollar; about 393,000 lead lines remain to be replaced.

Lead was widely used for water pipes from the late 1800s through the 1950s because it resisted corrosion, and many original lines are still in service. Chicago advises residents in buildings constructed before 1986, when lead was banned under the Safe Drinking Water Act, to assume their lines contain lead. Records of installations are often lost, incomplete or illegible, complicating inventories, said Joshua Klainberg of the New York League of Conservation Voters. He said leaving residents uninformed is unacceptable, noting that even an incomplete inventory can prompt precautions such as running the tap, using filters and cooking with cold water.

From 2027, utilities must replace 10% of lead pipes annually, typically with copper or plastic. Lines of unidentified material count toward that target, said Erica Galante-Johnson of the Environmental Policy Innovation Center, meaning more unknowns translate into more annual replacements. Each replacement generally costs between $8,000 and $15,000.

Most funding for identifying and replacing lead pipes comes from the 2021 bipartisan infrastructure law, distributed by states. This is the final year of dedicated federal funding for lead projects, though previously allocated money will keep flowing. Hayes warned that systems without inventories risk falling further behind as national efforts shift toward replacement.