The Allegheny County Sanitary Authority reached a compliance target established under its consent decree on Oct. 2 by increasing its wet-weather treatment capacity to 480 million gallons per day.
The 185 million gallon per day capacity expansion is expected to reduce regional sewer overflows by approximately 3.4 billion gallons annually.
The capacity increase is part of ALCOSAN’s Clean Water Plan, an initiative to upgrade wastewater infrastructure across the region. Construction on the treatment plant expansion has been underway since 2019 at the facility, which first opened in 1959.
Prior to the latest expansion, the plant had the capacity to treat up to 295 million gallons per day during wet weather, which was an increase from 250 million gallons per day established last fall. On Oct. 11, the facility sustained flows exceeding 295 million gallons per day during a regional rainfall event.
Construction at the facility has included building new treatment tanks, expanding preliminary and secondary treatment facilities, upgrading disinfection tanks and modernizing infrastructure.
The upgrades feature an improved solids-handling process that removes solids from secondary treatment to be thickened and sent to dewatering facilities, enabling a bypass mechanism when wet-weather flows exceed 295 million gallons per day.
Arletta Scott Williams serves as the executive director of ALCOSAN, leading the authority’s clean water programs and expansion initiatives.
“This is much more than an increase in a number,” Williams said. “Today, ’480′ reflects years of planning, construction and work by our employees and partners, demonstrating ALCOSAN’s commitment to clean waterways.”
Reaching the 480 million gallon daily treatment capacity serves as a step toward ALCOSAN’s ultimate target of treating up to 600 million gallons per day during wet weather.
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