Utilities don’t know where lead pipes are, and water testing offers limited safety assurances

Even if a community water system’s test results meet EPA standards under the Lead and Copper Rule, it doesn’t mean every home’s water is safe.

Editor’s note: This story has been amended since it was first published March 15, 2016 to clarify what a materials evaluation requires.

When the Environmental Protection Agency published the federal Lead and Copper Rule in 1991, its purpose was to minimize the amount of lead (and copper) in drinking water. Before the rule, the EPA allowed 50 parts per billion of lead in water and required utilities to test for lead levels before the water entered the distribution system. The rule changed testing procedures, established a goal of zero parts per billion of lead in water, and lowered the action level — the amount of lead that triggers a requirement that utilities take steps to lower lead concentrations — to 15 parts per billion. It also outlined water treatment protocols to reduce corrosion of lead pipes.

But even if a community water system’s test results meet the EPA’s standards under the rule, it doesn’t necessarily mean every home’s water is safe. And basic information that could help target water quality testing is often missing.

Lead as contaminant

Utilities check water for most organic and inorganic contaminants at the treatment facility, before it enters the distribution system and flows into people’s homes.

Lead is different.

Lead tests are done at customers’ taps, inside homes rather than somewhere in the distribution system or at the treatment plant.

That’s because lead enters the water by leaching out of the pipes and plumbing it passes through, primarily service lines. Service lines run perpendicular to the water main in the street, connecting it to individual homes. They’re usually owned in whole or in part by the homeowner. Treated, lead-free water could become contaminated by the homeowner’s own piping before hitting the tap.

What’s the goal of the testing?

To minimize the chances of pipes polluting clean water with lead, operators at the plant add chemicals to make the water less corrosive. The EPA rule’s testing guidelines are designed to measure whether a utility’s corrosion control plan is working. (Even the action level is based on this criteria: the action level of 15 parts per billion is not based on safety, but rather on what’s realistically achievable with proper anti-corrosion controls.)

“The goal is to understand if a water system has the potential to leach lead or copper and it’s from the perspective of an engineering control as opposed to health risks,” said Abigail Cantor, a chemical engineer who owns a consulting firm specializing in drinking water quality.

She said no one has figured out a way to get a complete picture of lead levels across a city — a statistical portrait of how many homes have elevated lead levels — without testing every home.

“Every plumbing system is different, and you may be in a house and that testing protocol doesn’t necessarily protect you. Their technique is not to protect the individual but to protect the general population,” Cantor said.

Pennsylvania has many lead lines, which makes testing important. But EPA requires its largest cities’ utilities — the Philadelphia Water Department (PWD) and Pittsburgh Water and Sewer Authority (PWSA) — to sample only 50 houses every three years. In Pittsburgh, that averages out to less than a single sample per neighborhood in PWSA’s coverage area. PWD tests more than double what’s required, but it’s still a tiny percentage of the city’s homes.

In 2013, in Pittsburgh, 10 percent of samples tested above EPA’s action level. But the sample size is too small to extrapolate the results. No one knows what percentage of homes in the city could have elevated lead levels.

In other words, having lead lines doesn’t mean you have contaminated water, but the EPA tests offer no assurances to households citywide.

Location of lead pipes unknown

As a precaution, EPA requires utilities to draw 50 percent of samples from the most vulnerable homes, with known lead service lines. “I think it’s important to make sure that systems are in fact going to the sites where they expect to find high levels of lead and copper,” said EPA’s Director of Ground and Drinking Water, Peter Grevatt. “That’s why EPA wrote this in 1991, because it would be a protective approach for communities.”

To make that possible, EPA requires water utilities to survey the materials in their distribution systems. But neither Philadelphia nor Pittsburgh has a comprehensive inventory that includes lead lines.

In Pittsburgh, service lines from the home to the curb are owned by the homeowner, and from the curb to the main line by the utility. The utility does not keep track of materials on either end of the line.  “We don’t have the exact number and location [of lead lines]. We’ve never actually surveyed that,” said Jim Good, until recently PWSA’s executive director.

A PWD spokeswoman said the utility in Philadelphia estimates there are 60,000 properties with lead service lines but “the age of the services to properties is unknown and there are no maps indicating locations of various materials.” Service lines in Philadelphia are entirely private and the utility does not consider them its responsibility.

Both the EPA and the Pennsylvania Department of Environmental Protection, which oversees implementation of the Lead and Copper Rule in the state, say ownership is not a consideration and the materials inventory should include lead service lines. A DEP spokesman said the inventory should be comprehensive, though some guidance documents also indicate that it needs only be extensive enough to locate a sufficient number of sampling sites.

Without a comprehensive inventory, targeting can be limited. The Pittsburgh utility sends letters to people who previously participated in testing and relies on random respondents to bill stuffers. “But we do ask homeowners, we ask them, ‘Well do you have lead?’ And sometimes they know. And that helps meet the criteria,” said Good.

Looking ahead

The crisis in Flint, Michigan has the utilities rethinking the status quo. PWSA is considering increasing testing frequency. PWSA and PWD are looking into doing a full inventory of pipes in their cities, and are starting to evaluate what it would take to replace all lead lines in their coverage areas.

The EPA is also revising the Lead and Copper rule, and that could include new testing protocols.

Meanwhile, both cities offer free lead testing to their customers, in addition to the testing they are required to do. For now, that may be the only way to assure the safety of an individual home’s drinking water.