Water is flowing again from Pittsburgh’s Highland Park 2 reservoir after a nine-month rehabilitation project that is part of the Pittsburgh Water and Sewer Authority’s $470 million refurbishing of the city’s drinking water system.

The authority announced this week that $24 million of work to reline the 125 million-gallon reservoir, install a new cover and prepare it to serve as a temporary water chlorination site has been completed. The reservoir, which opened in 1903 on the hill above the Pittsburgh Zoo & Aquarium, serves as the primary source of water for residents in Squirrel Hill, Downtown, the South Side and West End.

For the nine-month project, Layfield Environmental Containment of California drained the facility, installed a new membrane over the surface and covered that with a new liner. Additionally, a new floating cover was installed last year in what the agency said was the largest reservoir project in North America.

Improvements at the reservoir are among the early steps in the authority’s major overhaul of the Pittsburgh water system. Part of that work, called the Water Reliability Plan, was mandated by the state Department of Environmental Resources, and the authority decided to do the rest at the same time to improve operations and create more redundancy so other parts of the system can take over if one area has a problem.

The authority’s ultimate goal is to rebuild what is known as the clearwell in Aspinwall, a 6.14-acre underground tank across from the Waterworks shopping center, that holds 44 million gallons of water and provides the crucial, final step of making sure the water is free of pathogens before it is distributed. The century-old facility is currently the only place that process can be done, so the authority is creating other sites before the clearwell is closed for replacement in 2026.

After the clearwell is replaced, chlorinating facilities at Highland Park 2 and the Lanpher reservoir in Shaler will remain available in case there are problems in the future.

The agency has another reservoir that’s actually in Highland Park, but it’s not part of the major rehab project.

Other work involved in the project includes improvements at 14 buildings at the headquarters treatment plant in Aspinwall, where water is drawn and cleansed from the Allegheny River. Pump stations and supply lines as large as 8 feet in diameter that serve the reservoirs also will be upgraded, and a new pipe to bypass the clearwell will be completed before that facility is closed for replacement.

The pumping stations deliver as much as 76 million gallons of water daily through 965 miles of water lines across the city and a couple of North Hills suburbs. The project involves only part of the overall system that has five reservoirs and 11 tanks that can store 455 million gallons of water.

The agency increased rates $5.65 a month last year for the average customer that uses 3,000 gallons of water and expects another $1.44 monthly increase in 2023 to help pay for the work. The agency also is pursuing state and federal funds.

Upgrading the clearwell is expected to cost $65.8 million and take about two years to complete.

Ed Blazina

Ed covers transportation at the Pittsburgh Post-Gazette, but he's currently on strike. Email him at eblazina@unionprogress.com.

Ed Blazina

Ed covers transportation at the Pittsburgh Post-Gazette, but he's currently on strike. Email him at eblazina@unionprogress.com.