Maintaining efficient wastewater treatment plant (WWTP) operations requires rehabilitating aging facilities and incorporating new technology and equipment to keep pace with regulatory requirements and provide cost-saving efficiencies. In southwest Allegheny County, PA, the Bethel Park Municipal Authority has been upgrading their Piney Fork WWTP for the past 18 years through ongoing, phased improvements to address operational and maintenance inefficiencies. They are currently tackling wet weather grit and flow issues and upgrading solids processing capabilities. As Engineer of Record since 2008, Wade Trim assists the Authority with planning, design, construction management, and operations for WWTP improvements.

Design of a new, 10,000-square-foot headworks facility is underway to remove grit, debris, and wipes that have increased the plant’s rate of equipment failure and maintenance needs in recent years. The grit has also decreased capacity in the raw sewage wet well and primary clarifiers, requiring more frequent cleaning. Dictated by limits of the WWTP’s 17-acre site near the Piney Fork Creek, the headworks facility will be built within the geographic footprint of five rectangular final clarifiers that were abandoned after two new circular final clarifiers were constructed in 2015 to handle future flows. A new raw sewage pump station within the headworks facility is also being designed to increase wet weather capacity.

Solids processing improvements will be implemented further west at the WWTP including new treatment equipment and multiple updated pumping systems in preparation for potential future nutrient limits. After a mobile laser scan of the entire facility was completed, the data was used to create a digital twin environment via reality capture software. This approach has facilitated design of process and building improvements and saved the project team multiple trips to the site. These improvements will require redesigning the plant’s effluent water system and realigning the Catfish Run and Piney Fork Interceptors.

Design of the new headworks facility and solids processing improvements will be complete in mid-2022, with construction scheduled for completion in 2024.