Vollmer Associates has been selected by Southwest Delaware County Municipal Authority (SWDCMA) to provide professional engineering services for three different projects at the wastewater treatment facility for Aston and Middletown Townships, Delaware County, Pa. The projects involve a pretreatment local limits program, preliminary engineering for plant expansion and digester roof specifications for the Southwest Wastewater Treatment Facility.
The pretreatment program is in accordance with SWDCMA’s National Pollutant Discharge Elimination System (NPDES) permit, which sets requirements for developing and maintaining pretreatment programs. The goals of the program are to prevent the introduction of pollutants into the plant, which are incompatible with normal plant operation and improve opportunities to recycle and reclaim municipal and industrial wastewater and sludge.
Vollmer’s role is to develop those local limits so the facility can achieve pretreatment program goals through administration and sampling. Administration entails notice of violation (NOV) compliance, tracking users, engineering drawing review for new users, lab data review, intermediate user (IU) site inspections (new and existing) and surcharging. Sampling includes scheduling, setting up samplers and collecting wastewater, split sampling with the industry’s consultants, laboratory coordination and data entry.
The second project is preliminary engineering to evaluate the proposed expansion of the Southwest Wastewater Treatment Facility from the existing 6 to 6.5 mgd. Vollmer’s engineering review and evaluation included a hydraulic analysis and profile to determine the bottlenecks within the facility. A report was also developed to convey the firm’s recommendations for overcoming the identified problems, as well as the cost implications for the improvements. The preliminary design was focused around clarifier modifications and disinfection tank modifications.
The third project was initiated by the request of the SWDCMA board. Vollmer designed and prepared contract documents for the replacement of a digester roof. SWDCMA is proceeding with the cleaning of the digester tank, and if during the cleaning the roof shows signs of serious corrosion and potential structural failure, the roof replacement will be undertaken. Vollmer will assist in the roof evaluation as well as the bidding process.