It's been more than three and a half years since the Pittsburgh Water and Sewer Authority was put on notice for high lead levels in the city's drinking water, and new data shows the lead levels continue to be out of compliance.

On Friday, the Pittsburgh Water and Sewer Authority [PWSA] released the results of its lead water testing for the first half of 2019. The results showed that the agency’s water sample tested at 17.5 parts per billion (ppb) — above the Environmental Protection Agency’s 15 ppb threshold for requiring remedial action. During the last half of 2018, the testing shows 20 ppb.

The testing results showed an improvement after introducing the chemical additive orthophosphate, which creates a coating that can prevent lead from coming off of pipes and into the water. If the improvement shown in test results from June continued through the second half of the year, PWSA Executive Director Robert Weimar said he is “confident” the agency’s lead levels would come into compliance the second half of the year.

Due to a consent order PWSA signed with the Pennsylvania Department of Environmental Protection [DEP] in 2017, PWSA is required to replace 7 percent of its public lead service lines every six months until it comes into compliance. The agency has been replacing lead lines even faster than is required and plans to continue replacing lead service lines until none are left. PWSA has already replaced 4,200 lead service lines across the city since 2016 and has plans to replace 4,400 more, through a $49 million grant it received from the state.

“The goal is by adding [orthophosphate], we limit the amount of corrosion that occurs,” Weimar said in an interview Friday. “It’s not necessarily going to be zero, but it’s going to be close to zero and, as a result, the populace will be better protected until we can find and replace lead service lines.”

No amount of lead exposure is considered safe, according to medical experts. Lead exposure can reduce children’s IQ, reduce their attention spans and contribute to antisocial behavior. Pregnant women who are exposed to lead have increased chances of miscarriage, stillbirth and low birth weight.

According to EPA limits, 90 percent or more of households in the 176-home sample by PWSA are required to test below the 15 ppb threshold to be considered compliant. About 88 percent of PWSA households tested below 15 ppb during this six-month period.

Since 2016, there has been only one six-month period in which the PWSA’s lead levels tested below 15 ppb. It was in the first half of 2018. To get into compliance with the EPA, PWSA needs to test below 15 ppb for two periods in a row.

Although PWSA championed the current results as a drop from the previous reading of 20 ppb, levels have fluctuated since 2016, with readings ranging from 10 ppb to 22 ppb.

PWSA lead results since 2016:

January - June 2016 = 22 ppb

July - December 2016 = 18 ppb

January - June 2017 = 15 ppb

July - December 2017 = 21ppb

January - June 2018 = 10 ppb

July - December 2018 = 20 ppb

January - June 2019 = 17.5 ppb

In April, PWSA introduced orthophosphates into the drinking water. But the agency says that it can take up to six months for the orthophosphates to take full effect.

PWSA said the lead results have already been trending downward since the orthophosphates were introduced.

“We are encouraged by this round of sampling. This compliance data and our system-wide testing have demonstrated that the longer orthophosphate is present in our water system, the more effective it is at reducing lead levels,” Weimar said in a statement earlier today.

Introducing orthophosphates took more than two years, according to Weimar, including a one-year safety study required by the DEP, six months to receive approval and 10 months of construction to build the facilities to add the orthophosphate safely into the water.

Even though most of the households tested are within the EPA’s acceptable limits, a few households tested well above. A graph released by PWSA shows five tests above 50 ppb in May. PWSA staff follows up with any households that test above 50 ppb to try to determine the cause. Weimar said that very high samples are "predominantly" due to errors in the testing procedure.

In total, 18 households tested above 15 ppb in May, and one household tested above that threshold in June.

PWSA is not allowed to test the drinking water of the households where it has already replaced lead service lines for its official test results. PWSA currently estimates that about 15 percent of its 70,000 residential drinking water customers have lead service lines.

The agency is depending on orthophosphates to drive down its lead results in the short term: orthophosphates can reduce the amount of lead in the water of all homes, not just the homes that have had their lead lines replaced.

The agency predicts that even most households with lead service lines should be safe once the orthophosphate take full effect. “As orthophosphate continues to do its job, we anticipate lead levels to be reduced to single digit or non-detectable levels at most homes with lead service lines or plumbing,” Weimar said in a statement.

The next testing period will be July through December 2019.

“We now have every reason to believe our treatment upgrades are working as planned. Orthophosphate is helping reduce the risk of lead in water until we’re able to replace all of the remaining lead lines in our system,” PWSA Board Chair Paul Leger said in a statement.

Details of lead testing from January through June 2019:

113 households had a lead concentration of fewer than 5 ppb

29 were between 5 and 9.9 ppb

14 were between 10 and 14.9 ppb

6 were between 15 and 19.9 ppb

8 were between 20 and 49.9 ppb

6 were higher than 50 ppb

Update: This story was updated to include comment from PWSA Executive Director Robert Weimar.

Oliver Morrison is PublicSource’s environment and health reporter. He can be reached at oliver@publicsource.org or on Twitter @ORMorrison.