The South Monmouth Regional Sewerage Authority (SMRSA) operates an 8.5 million gallon per day sewage treatment plant in Wall Township, NJ. As a result of an extremely wet season and high rain event, SMRSA experienced a plant flow that was more than twice the norm, resulting in an overflow of its finishing ponds into a local waterway. The NJ Department of Environmental Protection (NJDEP) requested SMRSA take corrective measures to prevent this problem in the future.
Birdsall Services Group (BSG) was engaged to evaluate the sewer systems of the member municipalities in order to locate and quantify the sources of inflow and infiltration. BSG was also responsible for the design of the improvements to eliminate these problems.
The evaluation entailed the development of accurate system maps, per-formance of smoke testing, and visual inspections of manholes through-out the collection systems, flow monitoring to determine the areas most susceptible to inflow and infiltration and cleaning and television inspec-tion of the sewers to observe active infiltration and determine any pipe defects.
Results of these studies were evaluated and remedial measures were rec-ommended. The final design included the replacement of 14,000 linear feet of six-inch through 18-inch gravity sewers, the lining of an additional 6,000 linear feet of gravity sewers, point repairs to the pipes at 85 loca-tions, the replacement of 55 manholes and 350 laterals, and the internal lining and repair of 125 additional manholes.
BSG assisted the SMRSA in acquiring a $6.2 million loan through the New Jersey Environmental Infrastructure Trust.
There was a substantial decrease in wet weather and early morning flows reported at the wastewater treatment plant at the conclusion of the project.