Collecting wastewater from every business, facility and home in a community, and restoring it to clean water is essential to our continued sustainability. But it is a daunting and costly task for the Abington Regional Wastewater Authority (ARWA).
For starters, a significant portion of our underground collection system was built as early as the 1930’s. With a leak in the collection system the biggest problem is not sewage escaping, but rather rain and groundwater getting into the sewage system. Called Infiltration & Inflow (I&I) these leaks can increase the flow of liquid to the ARWA plant from about 3 million gallons per day (MGD) to almost 19 MGD. That’s 16,000,000 gallons of once clean water that now requires costly treatment. So these leaks are really expensive.
Sustained rainfall will push the volume of water beyond the treatment capacity of the current plant, and cause an overflow (or influent bypass) of untreated sewage into Leggett’s Creek. Although the frequency and the volume of the bypasses have been reduced since 2008, DEP issued three Notices of Violation to the Authority to inform the municipalities that the Notice included prohibition of any further issuance of building permits until a Corrective Action Plan (CAP) was submitted by ARWA and approved by DEP.
The Authority proposed a Regional Corrective Action Plan (RCAP) be jointly developed by the Authority and its three member municipalites. To respond and address issues in their own communities the municipalities chose their own professionals and contractors. Coordination was provided by the Authority and its engineering firm, Gannett Fleming Inc.
The municipalities and the Authority also agreed on a plan to update the existing municipal sewage facilities resulting in a Regional Sewage Facilities Plan Update (Act 537 Plan), which set forth efforts to reduce I & I as well as plant improvements necessary to meet new DEP mandates. DEP chose to recognize the positive cooperative efforts by ARWA as well as the municipalities by allocating a limited number of EDUs, allowing the issuance of sewer permits for new residental or commercial development.
ARWA eased the bypass situation by installing a new pump system of greater capacity and by performing a project on its main interceptor line to repair inflow leaks. However, ARWA still faced the challenge of EPA's mandate to significantly reduce the discharge of phosphates and nitrates which ultimately pollute the Chesapeake Bay. This solution will require extensive treatment plant upgrades and require new and complex environmental processes.
DEP evaluated the critical 537 Plan and issued it's approval in early 2012. That approval validates the extensive planning and effort of ARWA and the municipalities. It also put ARWA in a position to pursue PennVest grants and loans to finance its plant upgrade. Additionally the DEP approval keeps the project timeline intact, allowing ARWA the ability to meet EPA/DEP compliance deadlines for the plant upgrade during a period when interest rates are very low and construction costs are very competitive.