Duluth steps up diligence against lead in drinking water


Although recent tests have shown Duluth’s water supply to be in compliance with federal standards for the presence of lead, the city has launched a campaign aimed at educating people about how to minimize their risk of exposure to the potentially toxic heavy metal.

An initial round of water testing heightened concerns that some local residents may be exposed to unhealthy levels of lead, and while subsequent tests indicated Duluth’s water passes muster, Mayor Emily Larson said the city is stepping up its outreach efforts nonetheless.

“We know people take their water quality seriously. We do, too,” she said. “We spend a lot of time making sure people in this community are healthy and safe. So we want to make sure that residents have an opportunity to get the information they need.”

Test results

Every three years, Duluth is federally required to test for lead in the water of at least 30 homes with known lead service lines and/or plumbing components.

In June of this year, the city did just that, and four of 30 water samples submitted for testing came back with lead levels exceeding the 15-parts-per-billion threshold set as the upper limit of what the Environmental Protection Agency considers acceptable.

When the same 30 homes had last been tested in 2013, just one was found to be out of compliance, with a lead level of 20 parts per billion.

Alarmed by the results, the city hired an independent laboratory to retest the four houses with elevated lead levels, and three of those follow-up tests showed acceptable lead levels.

“The second result for three of those was much lower than the first,” said Lindsey Seifert-Monson, a water chemist for the city of Duluth.

The homes of concern also were tested for a third time by the Minnesota Department of Health to ensure lead levels had not returned to elevated levels.

“We were that concerned that there was an issue, that we took it upon ourselves to go above and beyond what we were required to do,” said Jim Benning, director of public works and utilities for the city of Duluth.

Seifert-Monson said it was later determined that some of the initial water samples with elevated lead had improperly been drawn from household taps not intended for drinking water.

Eric Shaffer, Duluth’s chief utilities engineer, referred to some of first results as “anomalies.”

“If we felt, for any reason, the high-testing values were a result of our treatment, we would have immediately addressed that,” he said.

Seifert-Monson said the city also expanded its analysis to include 30 more homes with lead plumbing or service lines, and just one sample of those properties’ water in the second round of testing was found to have lead levels exceeding the federal standard.

“Because we had four samples that were high, we wanted to expand it, just to get a bigger sample pool and to see how big the scope of the issue actually was,” Seifert-Monson said.

The Safe Drinking Water Standards Act requires cities to make sure that test results at the 90th percentile of elevation contain less than 15 parts of lead per billion parts of water. When all the numbers were crunched, Seifert-Monson said Duluth’s results showed 12.6 ppb at the 90th percentile, putting it well within compliance.

Informed public

While Duluth still has about 5,000 lead water-service line stubs in operation, Shaffer said the city has been systematically replacing them over time.

The city typically owns the portion of a service line that stretches from the main to the curb stop, usually located in the boulevard. From there to a house, the line is a homeowner’s responsibility.

Given the advanced age of much of Duluth’s housing stock, Benning said the far greater concern is the number of privately owned lead lines that remain in use.

Replacing a lead service line typically costs a homeowner roughly $5,000, he said.

“The best way to ensure you remove lead from your water is to remove the source, but there are cheaper ways to mitigate that,” he said.

One of the simplest and most effective things people can do is let their water run for a few minutes in the morning before drinking anything out of the tap, Benning said. A morning shower can do the trick.

Additional tips and advice will be shared with residents in a pamphlet that to be mailed out to city water customers in their bills

Shaffer said city engineering staff usually can consult records and advise individual residents whether they have lead service lines.

“We quit using lead in 1929, and so if your house was built after that, it’s a no-brainer.” he said.

But homeowners who are uncertain can contact the city at (218) 730-5200 for help.

Lead solder, which was used to join pipes up until the mid-1980s can also be a concern.

Residents can pay to have their home’s water tested for lead. The Minnesota Department of Health maintains a list of certified labs which can be accessed at (800) 798-9050. Testing usually runs about $50 or so.

Delivering safe water

Mayor Larson said Duluth continues to draw its water from one of the cleanest sources around — Lake Superior.

“The water source we have is the same as the water source we’ve had, which is good water to begin with,” she said.

Larson noted that recent problems with lead poisoning in Flint, Mich., arose only after the city began to draw its water from the Flint River.

Seifert-Monson said the city of Duluth also carefully monitors and adjusts the chemistry of its water to ensure it does not cause lead to leach out of pipes. Corrosion can occur if a water supply is allowed to turn acidic, and the city routinely boosts its alkalinity to guard against any such reaction.

Lead accumulates in the body over time and can lead to high blood pressure and kidney damage in adults.

Children are especially vulnerable to lead poisoning, which can result in low birth weights for infants, reduced IQs, learning disabilities and attention deficit hyperactivity disorder.

Larson said the city recognizes the critical role it plays.

“You can’t shop your water around. You’re getting it out of one tap, and that one tap runs back to the city and it comes back to what we do,” she said. “So it is a partnership with homeowners in how you make sure you’re mitigating any risk and you’re ensuring good health. But it’s really important, as a city, that we’re letting people know this is what we’re doing. Here’s what we’re finding out, and here’s all the information we have for you.”

Written by Peter Passi as published in the Duluth News Tribune.