Pittsburgh lead levels in water drop as PWSA claims orthophosphate working

Lead levels in Pittsburgh’s water system are decreasing but remain above federal thresholds, according to the latest test results released Friday by the Pittsburgh Water and Sewer Authority.

PWSA said the drop indicates an additive the authority started using in April that coats lead pipes to prevent them from contaminating the water is working.

The latest round of testing covers January to June. During that time, 176 samples from problem areas were tested. Of those, 88% were beneath the 15 parts per billion action level set by the Environmental Protection Agency. Twenty of the samples were above that level and six tested above 50 parts per billion, the PWSA said.

It’s a slight drop from the last testing period, July through December 2018, when 161 samples were tested and 24 were above 15 parts per billion.

The EPA requires action from test results than exceed 15 parts per billion in what it terms the 90th percentile results. The latest tests were 17.52 ppb, PWSA said.

It’s an increase of where the levels were in July 2018, when the PWSA 90th percentile results were 10 ppb. In January 2018, tests showed PWSA’s levels were 21 ppb.

In order to be considered in compliance with federal lead regulations, the authority would have to test at or below 15 parts per billion twice in a row.

In April, PWSA started adding orthophosphate, a chemical that coats the inside of pipes to prevent lead from leaching into water and has been a major component in the authority’s plans to address lead contamination. It will take about six months for the orthophosphate to reach its full effect, PWSA said.

“We now have every reason to believe our treatment upgrades are working as planned,” PWSA board chairman Paul Leger said in a statement.

PWSA also is replacing lead lines. Since 2016, PWSA has replaced more than 4,200 lead service lines as part of a consent agreement with the state Department of Environmental Protection.

About 15% of homes have lead service lines and PWSA also has plans to replace 4,400 public service lines that have lead in them through a $49 million state funding package. When it replaces a public line, PWSA offers no-cost private lead line replacements that are served by that line.

For more information about PWSA’s programs to eliminate lead from its water system, click here.