PWSA Turns on Second Orthophosphate Station

Mora McLaughlinMedia Release, News

Treatment will reduce lead levels across service area

Pittsburgh, PA – Monday, the Pittsburgh Water and Sewer Authority (PWSA) began adding orthophosphate to a second portion of the water distribution system. The northern portion of the City of Pittsburgh and the Borough of Millvale fed by the Lanpher Reservoir will now receive water with orthophosphate added. This will help to reduce lead levels in drinking water while PWSA works to replace lead service lines throughout the service area.

This comes two weeks after the first addition site, at Bruecken Pump Station, was turned on. This pump station serves Highland II reservoir which serves portions of the east end and the south end of Pittsburgh. The new feed system worked as planned to apply the dosage approved by state regulators. PWSA’s lab technicians and engineers continuously monitor the system’s water quality to confirm its application throughout water pipes across the city. 

The blue shaded area shows the portion of PWSA’s water distribution system that will receive orthophosphate-treated water as of Monday.
The yellow shaded area was the first portion of the system to receive orthophosphate approximately two weeks ago.

The decision to use orthophosphate comes after a year-long study conducted by local and international water quality experts as well as comprehensive regulatory approvals from the Pennsylvania Department of Environmental Protection (DEP). PWSA expects that orthophosphate will reduce corrosion from water services lines made of lead.

Orthophosphate is a food-grade additive that forms a protective layer inside of lead service lines, creating a barrier between the lead pipes and the water flowing through them. It is approved by the Environmental Protection Agency (EPA) and used in water systems across the world, including sections of the City of Pittsburgh served by Pennsylvania American Water Company.

Orthophosphate will create a protective barrier in lead pipes to reduce lead levels in drinking water.

The next location where orthophosphate will be applied is the Highland I Reservoir system in Highland Park. This orthophosphate facility was constructed this past year to house the necessary equipment to add the treatment to the system while also providing a community space within the park. You can read more about this project here.

The 2019 lead line replacement program is also now underway and will replace over 4,000 lead service lines. Customers can learn more about lead in water and PWSA’s Community Lead Response Program at

System Flushing Continues

PWSA will continue to flow water from fire hydrants throughout its distribution system to prepare the insides of pipes for the new orthophosphate-treated water. In addition, flushing will help bring the orthophosphate-treated water to customers more quickly. Over the next few months, customers may see crews opening hydrants to flush the water system and perform water quality monitoring

Customers may notice temporary brown or discolored water during this flushing program. To clear discolored water, customers can use the following instructions: 

  1. Run cold taps at the lowest point in the building for about 10 minutes or until the water runs clear.
  2. If it is still not clear, wait about 30 minutes and try flushing with cold water again.
  3. If the issue persists, contact PWSA Customer Service at 412-255-2423 and a representative can assist in addressing the issue at your property.