Lamprey River Coop Community Septic

Project completed May, 2013

Location: Raymond, NH
Owner: Lamprey River Cooperative
Engineer: Provan & Lorber

This project required the discontinuation of 21 individual existing septic systems with individual septic tanks and a common pump station and leach field. The system utilized multiple septic tanks (some single units some double units). These tanks lead to a gravity collection line which feeds to a pump station for final treatment within a raised leaching field. The project was funded with funds from the Rural Development Loan Fund, Community Block Grant Funding and local funding.

The project was the second phase of improvements to the Lamprey River Coop, the first being a water line installation. The project was to replace multiple Septic Systems which were in different degrees of maintenance and in some cases failing. The project was within a flood plain which increased the sensitive nature of the work throughout all phases of the project.

Issue: Maintaining access and use of all properties (including septic usage) during all phases of the project including the replacement of tanks and the 7 foot deep gravity main within the road.
Solution: Phasing of all work and working closely with suppliers and subcontractors to allow near seamless transitions.

Issue: Encountering large portions of the project were within ledge cuts.
Solution: The project required the removal of ledge to accommodate the installation of the new gravity sewer main for a majority of the project. With the use of a hammer on an excavator we were able to remove the ledge and not impact the nearby underground utilities including the new water system.

Issue: Requirements within the DES permitting required to compensate for loss of flood zone capacities with the installation of the raised leach field.
Solution: The Engineer, Provan & Lorber, designed two areas where materials were excavated to accept potential flood waters from the nearby Lamprey River. With funds remaining they were also able to perform work to provide a backup generator should a flood shut down power, this generator would continue to power the septic pump station.