The Allegheny County Sanitary Authority (ALCOSAN) is the clean water agency for most of Allegheny County, providing wastewater treatment services to 83 communities, including the city of Pittsburgh. ALCOSAN recycles as much as 250 million gallons per day of untreated wastewater into clean water that is returned to the Ohio River. In 2017, the treatment plant handled 73.5 billion gallons, with an average daily flow of 201 million gallons. That’s enough recycled, clean water to fill 1.5 million bathtubs.

Environmental practices

ALCOSAN operates under federal, state and county health regulations. It must meet all permit requirements, inspect industries under its jurisdiction and either reuse or otherwise dispose of the byproducts of wastewater treatment. ALCOSAN has been a consistently high performer in the Pittsburgh Green Workplace Challenge, its popular annual Open House is a zero waste event and there are green roofs, solar panels, permeable pavement, rain gardens and bioswales throughout the ALCOSAN plant. In 2016, a change to cleaner-burning incinerator fuel resulted in a 73 percent decrease in carbon monoxide emissions.

Environmental leadership

ALCOSAN is an environmental steward. ALCOSAN’s communications team participates in community events and festivals, meets with elected and appointed governmental leaders and offers in-class and after-school programs for children in preschool through high school. The outreach educates consumers, municipal officials and our youngest residents about the roles everyone plays in improving, protecting and preserving clean waterways for future generations.

Planning for a cleaner future

ALCOSAN’s Clean Water Plan is a long-term blueprint for improving the quality of the region’s waterways. The system becomes overloaded when it rains or when snow melts. This causes diluted, untreated wastewater — some contains sewage and other contaminants — to overflow into the area’s rivers, streams and creeks. The goal of the Clean Water Plan is to reduce those overflows by expanding the treatment plant, preventing excess water from entering the system, assuming responsibility for larger sewers to create greater efficiency and conducting long-term planning for the future. ALCOSAN has created GROW, a competitive grant program that already has awarded $19 million to municipalities for green infrastructure and other source reduction projects.

To learn more about ALCOSAN and its environmentally friendly practices, visit