In 2011, ARRO completed an infrastructure evaluation of the existing 0.28 MGD Spring Grove Borough wastewater treatment plant, which (at the time) included primary and secondary treatment of raw sewage for portions of Spring Grove Borough and Jackson Township in York County. Effluent was discharged to another treatment plant which provided tertiary treatment before discharging to a stream. All systems, including the piping, headworks, pumps, primary clarifiers, trickling filter system, secondary clarifiers, disinfection system, aerobic digesters, electrical system and controls, blowers, and pumps, were examined as part of this evaluation. Recommendations were provided for short- and long-term upgrades.

ARRO began the design of a biological nutrient removal treatment upgrade for Spring Grove when notification was received in 2013 that the downstream tertiary treatment facility would no longer be providing treatment for the Borough’s treatment plant’s effluent wastewater. ARRO was responsible for the design based on review of existing data, standard engineering practice, rules and regulations established by regulatory agencies, and preliminary effluent criteria provided by PA DEP. Design included the installation of new influent pumps, a grit removal system, two sequencing batch reactor systems with post-equalization, ultraviolet disinfection, and post aeration prior to discharge. The sequencing batch reactors were designed for both total nitrogen and biological phosphorus removal. The design also included rehabilitation of approximately 1,000 L.F. of effluent sewer pipe, which ran below existing railroad tracks and a building, retrofitting two existing clarifiers to serve as aerobic digesters, and provided new sludge dewatering facilities. Electrical, structural, and HVAC systems and upgrades were also provided as part of the design.