Intermunicipal Cooperation Ensures Success for Allegheny County Sanitary Authority's Pine Hollow and Deweyville Run Stream Removal Project

The Township of Kennedy, the Township of Stowe and McKees Rocks Borough are three contiguous communities located in the Chartiers Creek watershed in the western quadrant of Allegheny County. Each community owns and operates their own sewerage collection systems and relies on the Allegheny County Sanitary Authority (ALCOSAN) to provide treatment of domestic sewage flows. The Township of Kennedy operates a separate sanitary sewer system and storm water collection and conveyance system while Stowe Township and McKees Rocks Borough operate combined sewer systems. McKees Rocks Borough and Township of Stowe rely on their respective combined sewer systems to manage both storm water and sanitary sewer flows.Since 1994, ALCOSAN as well as communities with combined sewer systems such as McKees Rocks Borough and the Township of Stowe have been tasked with the responsibility to implement the requirements associated with the National Combined Sewer Overflow Policy (CSO Policy). Both McKees Rocks Borough and the Township of Stowe have entered into a Consent Order and Agreement with the Pennsylvania Department of Environmental Protection (PaDEP) to address CSO's within their respective communities. Kennedy Township entered into an Administrative Consent Order with the Allegheny County Health Department to locate and eliminate Sanitary Sewer Overflow (SSO) within their system.Since the issuance of the CSO Policy, ALCOSAN has undertaken a series of studies and has performed evaluations of the treatment plant and interceptor system including the completion of a Comprehensive Sewage Facility Plan prepared in accordance with Pennsylvania's Sewage Facility Planning Law, Act 537 (Act 537 Plan). Additionally, the ALCOSAN Regional Long Term Wet Weather Control Plan (LTWWCP) has been accepted by the United States Environmental Protection Agency (USEPA), the Allegheny County Health Department and PADEP.With Pennsylvania having more CSO communities that any other state and ALCOSAN serving one of the largest population centers in the State with a large number of tributary CSO communities, the success of the ALCOSAN regional project is a great measure of EPA's success in addressing this national issue. The solutions for ALCOSAN are intertwined with the tributary 83 municipal governments, in that the collection systems that contribute combined sewage are owned by each of the respective municipalities. In a number of cases, older portions of the tributary combined sewer systems incorporate the actual stream bed that traverses several communities. The associated spring water and storm water flows in these stream-based combined sewers exacerbate the ALCOSAN CSO volumes and associated flow reduction solutions. Only through effective intermunicipal cooperative arrangements can some of the complex sewer separation, sewer rehabilitation and other CSO mitigation measures be accomplished. The Pine Hollow and Deweyville Run Storm Sewer Separation Project is a key forerunner project that serves as the critical model for successful intermunicipal cooperation. This project was a high priory for ALCOSAN to finance in order to begin the reduction of combined sewer flow contributions and to demonstrate the success of intermunicipal cooperative efforts.Gannett Fleming, Inc. responded to the goals of ALCOSAN by initiating communications among the three municipalities and their consulting engineers. Through the identification of joint local benefits, we were able to negotiate the cooperative arrangement and facilitate the funding through ALCOSAN. This paper will address the manner in which the agreement was achieved, the project was managed and the communications were maintained through the project. The project technical background and requirements are addressed, as well as a description of the selected preliminary design alternative.