The Lively/Walden communal sewage system consists of seven sewage lift stations, the Lively wastewater treatment plant (WWTP), the Walden WWTP, and an extensive underground gravity collection system. The combined population of Sudbury’s satellite communities of Lively and Walden is approximately 7,200, with a 20-year projected population of 9,800. Junction Creek, which is the receiving water for treated effluent, is considered Policy 2 receiver for Total Phosphorous, mainly due to historical urban and industrial activities.
Our firm completed a Schedule ‘C’ Class Environmental Assessment (EA) of the Lively/Walden communal sewage collection and treatment system to ensure that long-term servicing needs were met for the communities. In conjunction with the EA, we also completed an inflow and infiltration study of the system to determine the extent of extraneous flows, and provide recommendations for their reduction. Technical reports were prepared to address the projected wastewater flows, required treated effluent quality, wastewater collection and pumping systems, and overall process requirements at the treatment plants. The preferred design concept included implementing a program to reduce inflow and infiltration; decommissioning the Lively WWTP and decommissioning the Anderson Lift Station; upgrading the Jacob Lift Station; replacing critical sections of gravity collection trunk mains; upgrading and expanding the Walden WWTP, including a new headworks facility, expansion of the existing extended aeration process, addition of ultraviolet disinfection, and tertiary treatment facilities; and improving treated effluent quality from the Walden WWTP.
Preliminary design details and costs were developed for the preferred solution, and construction phasing options were also considered. The study culminated in an Environmental Study Report, which summarized environmental impacts and mitigation measures, in addition to proposed operating strategies. Projected capital costs for the recommended upgrades were estimated to be $27M.