PWSA Adds Anti-Corrosion Agent to City’s Drinking Water

Orthophosphate is an anti-corrosion additive that creates a protective barrier in lead pipes. Image courtesy of the Pittsburgh Water and Sewer Authority.

The Pittsburgh Water and Sewer Authority (PWSA) (Pittsburgh, Pennsylvania, USA) recently announced that it would begin releasing an anti-corrosion additive into the city’s tap water. This additive, known as orthophosphate, is expected to reduce corrosion in lead pipes by preventing lead from entering the water supply. 

According to PWSA, orthophosphate is an Environmental Protection Agency (EPA) approved food-grade additive that forms a protective layer inside of lead service lines. A year-long study conducted by water quality experts concluded that orthophosphate is a more effective anti-corrosion agent than previous treatment processes involving soda ash and lime. Both the study’s findings and PWSA’s decision to employ orthophosphate was approved by the Pennsylvania Department of Environmental Protection (DEP) (Harrisburg, Pennsylvania, USA). 

Prior to releasing orthophosphate, PWSA’s Water Quality team performed water quality monitoring to prepare pipes for the newly-treated water. The team also analyzed water samples to determine if orthophosphate was properly implemented, all while working in close concert with the DEP. The recently concluded flushing schedule (March 18–29) was implemented in the West, South, and East End neighborhoods of Pittsburgh. 

“We’re excited about applying this upgraded water treatment method to protect our customers and reduce lead in water,” says Robert A. Weimar, PWSA’s executive director. Weimer adds that the organization plans to replace 4,000 service lines this year alone, with a long-term goal of removing all service lines from the city’s water system.

Source: PWSA,