About Us


The Municipal Authority of the City of Monongahela (MACM) Sewerage System consists primarily of the interceptor sewers, sewer regulators, flow metering chambers, remote pump stations, and treatment facilities required to provide sewage conveyance and treatment to flow originating in the City of Monongahela and a portion of Carroll Township. The City of Monongahela and Carroll Township are primarily responsible for the collection and conveyance of sewage from their respective service areas into the MACM interceptor system.

Initial construction and operation of the MACM system began in 1964 with the completion of primary sewage treatment facilities, interceptor sewers, sewer regulators, and the Pigeon Creek pumping station. Subsequent upgrades to the treatment plant were completed in 1975 to provide secondary levels of treatment to the influent wastewater. Further expansion of the conveyance system was completed in 1978, consisting primarily of the extension of the interceptor system to the City's boundaries, the construction of metering stations, and an additional pumping facility to serve Carroll Township and some previously unsewered areas of the City.

Since 1978, improvements to the conveyance system have been completed on a periodic basis. Improvements to the sewage treatment plant have also been performed on a periodic basis.

The Authority has undertaken a Corrective Action Plan (CAP) to address needs in both the sewage system and the treatment plant. In July of 2000, the Authority received a PENNVEST grant in the amount of $1,000,000 and a 20-year, 1.0 percent PENNVEST loan in the amount of $1,710,000 to finance the Phase I Sewage Treatment Plant Improvements Project and Interceptor/Trunk Lines Rehabilitation Project. The sewer rehabilitation portion of the project included manhole-to-manhole lining of nearly 1,800 linear feet of leaking and cracked pipe. The main focus of the sewage treatment plant improvements portion of the project was the replacement of old and worn equipment to increase the efficiency of the plant’s biological process and significantly reduce or eliminate NPDES permit excursions.

The Authority, the City of Monongahela, and the DEP entered into a Consent Order and Agreement dated April 23, 1999. The COA required the development of a COA Action Plan. The general approach of the Action Plan was to modify the facilities at the sewage treatment plant to bring the facility into compliance with the requests of the DEP. A PENNVEST application for Phase II of the COA project was submitted on January 14, 2003, and a loan award was received on May 7, 2003 in the amount of $5,952,100. Construction of the Phase II Sewage Treatment Plant Improvements began in January 2004 and included new flow equalization facilities, new grit removal facilities, a new secondary clarifier, modifications to flow channels to improve plant hydraulics, renovations to existing clarifiers and sludge processing equipment, and various architectural and security improvements. Construction was completed and the facilities have been operated by the Authority since July 2005.

All requirements of the Consent Order and Agreement (COA) between the MACM, the City of Monongahela (City), and the DEP dated April 23, 1999 have been satisfied.