Complete Process Analysis of WWTF at Otter Valley Union High School
Weston & Sampson provided a complete process analysis of the wastewater treatment facility (WWTF) that included a mass balance, hydraulic profile, and process design calculations to assess the facility against the published standards of the NEIWPCC TR 16, Ten States Standards and Vermont Department of Environmental Conservation (VTDEC) WWTF Guidance Documents.
The existing WWTF was designed and built circa 1975. It is a super primary lagoon followed by a circulator (clarifier) and multi-media gravity filter providing advanced treatment before disinfection in a chlorine contact chamber. The WWTF was designed for 25,000 gallons per day of flow and to discharge an effluent with a quality of 30 mg/l of Biological Oxygen Demand (BOD) and 30 mg/l of Total Suspended Solids (TSS).
As part of the project, Weston & Sampson conducted an existing conditions assessment for an above-ground steel clarifier and tertiary sand filter. These structures were found to be in good structural condition, and Weston & Sampson recommended that they be sandblasted, painted, and restored to use. Performing this evaluation saved the client over $100,000 in structure replacment costs.
Project deliverables include a comprehensive report documenting the findings of the facility inspection and identifying shortcomings within the existing facility. This assessment includes identification of present and long-term needs for a 20-year planning period.