The Pittsburgh Water and Sewer Authority is set to begin a $24 million filter rehabilitation at its water treatment plant near Aspinwall.
PWSA board members are scheduled on Friday to award contracts for the project, which represents about 15 percent of the authority’s $156 million, four-year capital budget and should help ensure quality water for 20 years.
“If we don’t do this, we could lose our ability to filter our water effectively, efficiently and within compliance,” said Ronald K. Duray, PWSA director of water quality and production.
Spokeswoman Melissa Rubin said the authority has not been cited for a water quality violation in more than 40 years.
The filters are not filters in the traditional sense.
They are 18 basins known as “rapid sand filters” measuring 46 feet wide, 57 feet long and 13 feet deep. The basins are filled with layers of coal, sand and gravel, in that order, from the top down and can hold up to 225,000 gallons of water.
Water passes down through the layers, which filter particles and impurities during the plant’s last phase of treatment. The water is piped to a collection tank for distribution to about 300,000 customers in the Pittsburgh region.
“Basically, they’ve reached the end of their useful life,” Duray said.
PWSA has planned the project for six years. Completion will take about three years.
Three basins at a time will be taken out of service while contractors replace the layered material and install new electrical components, lighting, heating and air conditioning and pipes and valves.
“This is the largest project in the capital budget,” Rubin said.
Duray said the plant must clean the basins every 100 hours by pumping water up through the layers. That will increase by 40 to 70 hours after the filters are rehabilitated, he said, adding that PWSA would need state Department of Environmental Protection permission to extend backwashing time.
“If we increase the time, it’s pretty obvious you save money” on chemicals and water necessary to backwash basins, Duray said.
Bob Bauder is a staff writer for Trib Total Media. He can be reached at 412-765-2312 or email@example.com.