Accommodating a Community's Changing Wastewater Needs
Franklin Electric worked with the Lemon Township & Tunkhannock Township Joint Municipal Sewer Authority to design a low-pressure sewage collection system to accommodate the lakeside community’s changing wastewater needs.
Customer Challenge
For decades, the 390+ residents who lived on and around Lake Carey in Pennsylvania utilized septic systems for their homes and businesses – and those systems were aging. The soil of the property lots was mno longer compatible for the septic systems, which increased the risk of groundwater contamination in the community. In 2015, the Pennsylvania Department of Environmental Protection mandated a 537 plan around the lake, and the Lemon Township and Tunkhannock Township Joint Municipal Sewer Authority began the design and bid process for a new sanitary sewer collection and treatment system. The project was projected to be multi-year and massive, funded in part from a $13+ million loan from the Pennsylvania Infrastructure Investment Authority (PennVest).
However, the project was slow in moving forward due to several challenges related to the area’s topography. Given the sewer system’s location – near a 182-acre recreational lake – the solution needed to move residential and commercial waste “uphill”: essentially out of the natural bowl that the lake created. A gravity-fed system simply wasn’t feasible and would create a high risk for inflow and infiltration issues. With 8.5 linear miles of total pipe needed and the longest segment running over 4 miles, friction losses were also a concern. Adding to the challenge was the overall ability to design the right system: because alternative sewer systems, like low-pressure designs, are relatively new to the market, engineering firms often don’t have extensive experience laying out a complete system.
The Solution
The Township realized early on that an alternative sewer design needed to be considered – and a lowpressure sewage collection system became a top contender. Given their experience in low-pressure systems design and the product’s efficient, proven performance, the Franklin Electric team was offered the chance to perform a hydraulic analysis of the area using the Franklin Electric FPS PowerSewer® System. This demonstration, which included calculations across 47 zones, helped prove how the system would perform given the challenging location and topography.
The hydraulic analysis helped alleviate concerns, yet the Franklin Electric team took it a step further, working closely with the design and engineering group to complete all of the backend design and layout for the system, including all of the piping runs and sizes, capacity requirements, placement of high head versus standard pumping systems, etc. The PowerSewer System provided the minimum 90 gallons of working volume required, calculated from the collection tank bottom to the inlet invert. The system also wouldn’t need lift stations and the lines could be installed closer to the flow of the terrain. Once these lines went over a certain high point, the PowerSewer System’s anti-siphon check valve would overcome siphoning conditions going downhill on the backstretch.
The Results
The government-funded project had strict bid parameters that needed to be met. While Franklin Electric’s solution didn’t deliver the lowest upfront cost, it offered cost saving benefits over the system’s life cycle — meaning an improved total cost of ownership compared to other systems. The product itself delivered the overall high quality required for long-term performance, with a powder-coated body, solid 300-series stainless steel shaft, and carbon ceramic mechanical seal. Franklin has also been able to stagger delivery of the 384 units to accommodate the onsite installation schedule: ramping up delivery when needed over the projected 10-month timeline. Installation and long-term maintenance are also delivering financial and time-saving benefits. The one-piece roto-molded HDPE polyethylene tank does not require the contractor to cut holes in it since all penetrations are made in the factory. The system’s C-Channel assembly release from the top of unit, simplifying accessibility and allowing for easy installation and maintenance of the pumps.
Once all of the units are installed they will become fully operational for residents and businesses – alleviating the issues the previous septic systems caused and providing a better overall long-term solution to maintain the integrity of the environment near the lake.