Pennoni Perspective Volume 22 • Issue 2 • Summer 2018 - Page 26

All set for the future Many of us do not think about our sewer systems until there is a problem in our home or business. The officials responsible for these sewer systems are constantly monitoring to ensure that capacity or treatment issues do not arise. For East Goshen Township in Chester County, PA, their sewer system needed a capacity expansion and treatment upgrade to meet the current and future needs of the community. Not a simple task by any means, a multi- million-dollar, multi-project, 10-plus year sewer system expansion and upgrade was chartered to address capacity for future growth, improve water quality, modernize facilities, and proactively address future regulatory requirements. 26 | P E N N O N I As of 2005, the Township’s aging and undersized Ridley Creek Sewage Treatment Plant (RCSTP), an extended aeration wastewater treatment plant, and upstream conveyance system could no longer accommodate peak influent flows, lacked operational redund ancy in the event of equipment failures, and had experienced multiple overflows into an adjacent wetland area and stream. Pennoni was tasked with performing a Township-wide sanitary sewer needs assessment at that time and determined that the municipality’s projected full build- out sewer flow would be 330,000 gallons per day (gpd) more than their available capacity, a difference of 25 percent. At the same time, PADEP was also requiring the Township’s Lockwood Chase Sewage Treatment Plant (LCSTP), a 25,000 gpd aerated lagoon spray irrigation facility, be upgraded to comply with much more stringent treatment requirements as part of a NPDES permit renewal. The Township knew they needed to make extensive system upgrades, but the multi- faceted project was going to take time. Working hand-in-hand with the East Goshen Municipal Authority and Township staff and officials, Pennoni performed a study to evaluate several different capacity expansion alternatives, including pumping to several other nearby treatment plants and demolishing versus replacing the RCSTP, amongst other things. The study recommended the RCSTP be upgraded by nearly doubling its capacity to 750,000 gpd average and 3 million gallons per day (mgd) peak with a new Sequencing Batch Reactor activated sludge treatment process, decommissioning and closing the LCSTP, and constructing five sewer diversions to divert flows from other Township sewage drainage areas to the RCTSP after expansion. The planning included the creation of a hydraulic