Fifteen years before lead contamination of a Michigan city’s drinking water became a public health crisis, Madison was on its way to eliminating its worst risks through a costly effort that replaced more than 8,000 lead water pipes.
There are cheaper ways to meet federal standards, but none as effective, said the consultant whose work helped drive the effort.
“Wherever there is a lead pipe in any city, it should be replaced,” said Abigail Cantor, an independent consultant whose tests on old pipes sparked the city’s 11-year, $15.5 million effort to replace every lead pipe in the water system.
Madison is believed to be the only community in the country to have taken such a radical step. Cantor has been honored in Wisconsin and nationally for her research, and the city’s solution has caught the attention of experts and utility officials elsewhere.
But an update the U.S. Environmental Protection Agency is making to its lead and copper regulations isn’t likely to substantially change an approach Cantor says is dangerously simplistic.
The federal rule doesn’t take into account the complex nature of drinking water systems, which can deliver hazardous, temporary spikes in lead levels that aren’t detected by infrequent federally mandated sampling, Cantor said.
Even water systems that are in full compliance with federal standards can still have up to 10 percent of tested households exceeding the federal “action level” for the toxic metal.
The stakes are high because lead causes irreversible brain damage. Scientists have grown more concerned recently about its effects on children. In 2012, the Centers for Disease Control cut by half the blood level that is considered high. The metal has also been linked to heightened risk of fetal death and other problems.
The first step toward addressing risks from tap water should be to do what Madison did, said Cantor, who continues to investigate water supply problems for clients from her West Side office.
When samples show too much lead in more than 10 percent of samples, the EPA calls for adding chemicals that create a coating on pipe interiors that prevents water from absorbing the poisonous metal. Cantor said it works well on new lead pipes.
“But the problem is the pipes in this nation are not nice clean new lines,” Cantor said. “They are filled with a lot of precipitants ... what I call a soup of metals and microbiological issues.”
Even after Madison replaced most of its lead pipes, spikes in lead content were discovered. The city countered the problem, but it illustrated one of scores of complex, difficult-to-predict interactions that occur in water supplies.
The chemistry and biology of water varies widely depending on its sources in hundreds of lakes, rivers and underground aquifers. Variable factors such as purification methods, temperature, storage time and materials that have accumulated for decades in pipes add another layer of unpredictability, Cantor said.
Madison’s decision to replace its pipes was anything but easy, with strong objections to the cost and scale of the effort. Even nearby communities with similar water chemistry have not opted for a similar approach.
“Even if the chemistry is right, economic sustainability is another hurdle,” said Gregory Harrington, a UW-Madison professor who specializes in water supply engineering. “In other words, is the community willing to pay for that solution?”
Differences in Flint
What happened in Flint, Michigan, has commanded international attention in part because state officials misled the public about lead levels after tests showed serious problems.
In Wisconsin, after samples of Madison’s drinking water found too much lead in 1992, the state Department of Natural Resources issued a series of consent orders to make sure Madison found a solution.
Nearly 10 years later, rather than using the conventional and relatively inexpensive solution of chemical additives, the city persuaded the DNR that it should replace every lead pipe in the city, said Joe Grande, the Madison Water Utility’s quality manager. EPA rules can require limited, gradual pipe replacement, but only if chemicals don’t work, and only until standards for 90 percent of tested taps are met.
“It was a very unusual route,” Grande said. “I don’t know of any utilities that have opted to do lead service replacement instead of corrosion control.”
Lead pipes connecting homes to iron water mains were installed in the early part of the 20th Century. Lead’s flexibility meant it resisted cracking when the soil shifts.
But over the years, evidence mounted showing the metal leached into the water and caused permanent health problems.
A 1991 EPA rule required sampling of water from homes known to have lead connections. Water systems needed to take steps if tests showed more than 10 percent of samples had lead concentrations exceeding 15 parts per billion.
Madison’s showed 16 parts per billion or less in 90 percent of samples in 1992, and the water utility began testing chemicals to reduce pipe corrosion and keep the lead in check.
Cantor worked for a private consultant the utility hired, conducting trials with the chemicals on sections of old pipe.
“Basically I just questioned authority, because what the regulation was telling us to do didn’t match up with what I was seeing in the field,” Cantor said.
The unique and complex chemistry and biology of Madison water and the residue in its pipes didn’t react as expected. One type of phosphate that was supposed to reduce lead actually increased it fourfold, Cantor said.
Another phosphate did lower lead levels to some extent, but there were concerns because phosphates act as plant nutrients.
Pumping nutrients into the water supply at the front end would tend to boost the fertilizing potency of sewer water discharged at the other end. The area’s sewage treatment plant had recently spent millions of dollars to reduce the area’s nutrient discharges, which cause excessive algae and weed growths in lakes and streams, and officials didn’t want to offset those gains, Grande said.
But the alternative, replacing lead pipes, would be costly, and the water utility was legally responsible only for the lead pipe that ran from the iron water mains under the streets to the property line of a home or business. The rest of the lead connection leading to the tap was the property owner’s responsibility.
Grande said the DNR insisted on a guarantee that all the lead would be replaced, so the city passed an ordinance requiring residents in older properties to replace their pipes, setting off a backlash over costs that would run to thousands of dollars for each homeowner.
“We had to figure out a way, particularly for low-income people, how they were going to be able to afford that,” said Sue Bauman, who was mayor from 1997 to 2003.
“It was controversial, and we went around and around about it,” Bauman said. “People didn’t want to pay to have their laterals (pipes) done, but they also didn’t want the chemicals put in the water.”
In the end, the city agreed to pay up to $1,000 of the property owner’s cost.
An agreement was signed with the DNR on Dec. 21, 2000, and work was soon underway.
Lead levels rose again
Even after most of Madison’s lead pipe had been replaced in 2007, tests were showing surprising spikes in lead concentrations in some areas, Grande said.
The utility determined that the culprit was manganese, a metal component in material that accumulates on interior surfaces of water pipes, Grande said.
Manganese was absorbing small amounts of lead that appears naturally in the water. Over time, it concentrated the lead until it reached levels that posed health concerns. The utility began a program of flushing water through the pipes to remove clinging contaminants.
Cantor said flushing programs are an important step. Iron and manganese in mains and inside a home’s plumbing can concentrate lead and then release it, she said.
She recommends that homeowners have samples tested for lead at private or state laboratories.
Many water utilities across the country wrestle at one time or another with lead problems. Some Wisconsin water systems outside of Madison are considering replacing at least some pipes, including connections on private property, but most use phosphate additives to control lead, DNR spokesman George Althoff said.
Some communities have considered a half measure: Just replacing the public portion of the lead service lines while leaving the property owner’s portion untouched. But research suggests it should be all or nothing because disturbing one end of the pipe can shake loose hazardous sediments at the other.
Grande said he didn’t expect to see many emulate Madison’s approach because of the price tag. Estimates to replace the lead water service lines in Flint, for example, start at $60 million — and go up dramatically from there.
But Madison officials say it was money well spent.
“Hopefully our example will be spread widely and it will provide an alternative approach,” Grande said. “We found it very successful.”