MADISON — Experts, and even some regulators, say existing laws are failing to protect Wisconsin and the nation from harmful exposure to lead in drinking water that leaches from aging plumbing — a danger illustrated by the public health crisis in Flint, Mich.
At least 176,000 lead service lines connect older Wisconsin homes to the iron water mains that deliver municipal water, according to an estimate by the U.S. Environmental Protection Agency. Milwaukee alone, where 60 percent of the state’s known lead-poisoned children live, has 70,000 lead service lines.
Regulators concede that the Lead and Copper Rule, the 25-year-old federal law that seeks to minimize the danger from these lead pipes and indoor plumbing fixtures, is failing on several fronts:
- Methods for sampling often fail to detect the highest level of lead in a consumer’s home.
- Too few homes are sampled, and those that are may not be in the neighborhoods most at risk.
- The requirement that utilities replace some lead lines when they exceed federal thresholds may actually cause dangerous increases of lead in drinking water.
- Lead is primarily leached into Wisconsin’s drinking water by the corrosion of lead pipes and indoor plumbing components.
Health effects of lead include irreversible brain damage in children under age 6 and an increased risk of miscarriage in pregnant women.
Decades ago, when it became clear that lead was one of the worst toxins for the developing brain, U.S. regulatory agencies began to eliminate the heavy metal from gasoline, paint and new plumbing. But the efforts to address the nation’s existing water infrastructure were limited.
Marc Edwards, an engineering professor at Virginia Tech University and one of the nation’s foremost experts on lead in drinking water, helped Flint address its massive problem with lead-contaminated drinking water that has poisoned a number of the city’s children.
Edwards said millions of U.S. homes have some lead components in their water delivery system, although “no one knows” the exact number. He agreed with some who have called the widespread risk posed by lead pipes and the astronomical cost to replace them one of the biggest environmental disasters in U.S. history.
The American Water Works Association estimated in 1990 that the U.S. water infrastructure had about 3.3 million lead service lines and 6.4 million connections made of lead, many of them installed well over 100 years ago. Wisconsin is one of nine states, all in the Midwest and Northeast, where they are particularly common.
In addition to Milwaukee, several other Wisconsin communities have a high percentage of lead service lines, including Wausau, Wauwatosa and Racine, according to the EPA.
A 2008 study found that these service lines account for 50 to 75 percent of lead contamination in public tap water, with most of the remainder due to indoor lead pipes and plumbing components, such as faucets and connections.
The risk of these aging pipes is so high that Madison’s public water utility made the controversial decision to replace all of its lead service lines beginning in 2001 — a move now seen as a model for other cities.
The problem posed by lead service lines is likely underestimated in Wisconsin, where census figures show about 27 percent of homes were built before 1950 and 63 percent before 1980.
Miguel Del Toral, a regulations manager at the EPA’s Chicago office, said that after five years of effort, he could only track down written documentation of lead pipes in 113 Wisconsin communities in 47 counties. The number of lead pipes outside of these communities is anybody’s guess.
In addition, tap water from only a fraction of the 176,000 buildings in Wisconsin on known lead service lines is tested as part of the federal Lead and Copper Rule. The law requires utilities to collect water samples from households known or suspected to be served by these pipes, but a 1984 EPA survey showed one-third of utilities did not know how many lead pipes they had.
Milwaukee Water Works is currently on a reduced monitoring schedule because of a history of compliance with the federal law; it only has to test for lead in 50 homes every three years. Even before this schedule became effective, the city only had to test 100 homes per year for lead.
Finally, some testing under the federal rule may not accurately reflect consumers’ actual lead exposure, according to a study by Del Toral and another by Edwards.
Del Toral’s 2013 study found wide swings in lead levels in Chicago households when tap samples were taken 12 or more times during a single day. He concluded that “the existing regulatory sampling protocol under the U.S. Lead and Copper Rule systematically misses high lead levels and potential human exposure.”
A water utility is compliant with the federal law when at least 90 percent of household samples are below the action level of 15 parts per billion (ppb) of lead. Even when utilities greatly exceed the action level, unless it involves more than 10 percent of the samples, no system-wide remediation efforts are required.
If more than 10 percent of samples exceed 15 ppb, a water utility may be required to install or improve corrosion control. This involves adding a chemical, such as orthophosphate, to the water to make it less likely to eat away at lead pipes.
Systems required to use corrosion control include those serving 50,000 or more customers and those in which 10 percent or more of the water samples tested above the federal action level.
In April 2014, when Flint began drawing its drinking water from the Flint River without adding anti-corrosives, blood lead levels spiked in children, inciting a public health crisis, protests and angry finger-pointing. The city has now switched back to Detroit water.
“(Corrosion control) is a complicated subject that has kept water quality experts searching and even arguing for decades,” said Abigail Cantor, a Madison-based chemical engineer who has worked with several Wisconsin water utilities as a technical consultant.
In addition, orthophosphate harms surface water quality. When water treated with orthophosphate is released into lakes by the wastewater treatment plant, it contributes to algal blooms, oxygen depletion and production of toxic chemicals.
That is one reason why Madison, a city proud of its lakes, rejected corrosion control and instead replaced all of its lead service lines with copper pipes.
Required pipe replacements can boost danger
When a utility is not in compliance with the federal law and corrosion control is ineffective or rejected, it must replace 7 percent of the lead service lines that it owns. Additional replacements are required every year until the utility comes back into compliance.
The utility-owned portion of the service line typically runs from the water main to the curb stop, while the section between the curb stop and the house is usually privately owned.
However, replacing only the utility-owned portion of the pipe, a so-called partial replacement, can have severe unintended consequences: it may increase, rather than decrease, lead levels in consumers’ tap water.
Several factors can cause these lead spikes. One of them is the physical shaking of the pipes during replacement work, which can knock off the lead inside. Del Toral recounted one case in Chicago in which sediment measuring 125,000 ppb of lead came off a pipe.
“That would pass straight through a kitchen aerator and would put an infant or child in the hospital immediately, if not worse,” he said.
Lead levels in tap water may also increase after partial replacements due to a chemical phenomenon called galvanic corrosion.
“When old lead pipe is connected to a new copper pipe, the contact of the two metals creates a battery effect that activates lead, so that it enters the water at an accelerated rate,” said Yanna Lambrinidou, one of Edwards’ colleagues at Virginia Tech University.
In 2012, a federal Centers for Disease Control and Prevention study found high blood lead levels among children whose homes had undergone partial pipe replacement. The researchers concluded that “the practice of partially replacing lead service lines as a method to comply (with the Lead and Copper Rule) should be reconsidered.”
Water main repairs can also cause a physical disturbance of lead service lines, resulting in the same risk of lead scale particles being released into the water. Milwaukee has hundreds of water main breaks a year.
“The water main work is the primary disturbance of the lead lines. That is going on, unregulated, on a daily basis in all major water systems in the country,” Del Toral said. “That’s a very big concern.”
Paul Biedrzycki, director of environmental health for the city of Milwaukee, shared Del Toral’s concern. He said such work poses “a very real public health threat.”
Milwaukee Water Works spokeswoman Sandra Rusch Walton countered that the city takes precautions against lead when it repairs broken water mains by flushing the line and asking homeowners to do the same.
Cantor said that may not always have the desired effect since flushing sometimes “riles up pipe wall debris” and “makes matters worse.”
New regulations years away
A quick fix of the nation’s lead pipe problem is unlikely. Lambrinidou was part of an EPA-convened working group tasked with proposing changes to the Lead and Copper Rule. The group released its final report in August. Lambrinidou estimates it will take at least another five to seven years before any revisions go into effect.
One of the group’s major recommendations: requiring water utilities to pursue full replacement of all lead service lines in collaboration with customers.
Edwards said until all lead pipes in the water infrastructure system are safely replaced, consumers are largely on their own when it comes to protecting their families from lead.
“If we don’t make a decision right now to get these lead pipes out of the ground, when are they going to be removed?” he asked. “They just pose an unreasonable health risk to future generations.”