Before the Penn Township in Pennsylvania contracted with a wastewater treatment services company, Severn Trent Services, about 18 months ago, the township’s wastewater treatment plant consistently exceeded discharge limits of several contaminants including ammonia-nitrogen, total suspended solids, total phosphorous and carbonaceous biochemical oxygen demand, reports Water and Wastes Digest.
Since the partnership, the wastewater plant has had no discharge permit or water quality violations.
Other benefits include the repair and replacement of a number of malfunctioning water meters, which had become a financial issue for the township, reports Water and Wastes Digest.
The contract with Severn Trent Services covers operation of the wastewater system including responsibility for the treatment facility and the pump stations and maintaining the distribution system.
The water system consists of one 225-gallon per minute submersible well pump using sodium hypochlorite disinfection and polyphosphate to sequester manganese, one well, the distribution system, fire hydrants and an elevated storage tank, according to Severn Trent Services.
The wastewater system includes a 0.650-million gallon per day sequencing batch reactor (SBR) plant using ultraviolet disinfection, aerobic digestion and dewatering together with seven wastewater pump stations and the collection system.
Some of the improvements made to the systems included the installation of a chlorine analyzer that will signal an alarm if the chlorine residual drops below an operator-inputted set point. The company also connected the chlorine analyzer to a relay that shuts down the well pump if the residual drops below the set point.
Severn also added safety procedures for performing potentially hazardous tasks such as inventorying, storing and disposing of chemical and hazardous substances, according to the company.
A new water treatment facility is currently under development that will feature microfiltration and nitrate removal, according to Severn.