As part of Bristol Borough Sewer Authority’s ongoing multi-million dollar capital improvement program, G&A designed the replacement of two  rotating biological contactors (RBCs) at the  Borough’s sewage treatment plant.  Both RBC units had been out of service for more than 10 years due to broken shafts.  In addition to design, G&A provided construction administration services as well as structural review and construction oversight for replacement of damaged concrete in the RBC tanks during the project.

RBCs are attached growth reactors; in this case, bacteria grow on the media, which is high and medium density polyethylene.  The RBCs then slowly spin through the wastewater stream, allowing the bacteria to come into contact with and thus treat the wastewater.  The completion of this project helps BBSA continue to maintain compliance with the stringent effluent limitations set by the Pennsylvania Department of Environmental Protection and Delaware River Basin Commission.