Digester and Pump Station Evaluation for Rutland, VT
Weston & Sampson was retained by Rutland for three recent projects at the city’s 8 million gallons per day (mgd) tertiary wastewater treatment facility (WWTF).
Digester Cover Evaluation & Replacements
For two of the WWTF’s five 40-foot diameter anaerobic digesters, we evaluated the condition of the digesters and specified repair of one cover and designed the replacement of another, which capture gas for system mixing and heating.
Pump Station Evaluation
For the 20,000 gallons per minute (gpm) River Street pump station, Weston & Sampson evaluated five 150-Hp vertical turbine centrifugal wastewater pumps. As a result of flooding damage, storm debris and brick from the partially collapsed East Creek interceptor filled the wet well and was affecting pump performance with plugging, air binding, and excessive vibration. Since none of the pumps were capable of pumping at specified capacity, a vibration analysis was performed and pumps were opened to inspect internal components. Following the inspections, we recommended cleaning and repairs to the interceptor and wet well; partial replacement of pump internals such as bearings, seals, and impeller wear rings; and refurbishment of suction heads and “grit shield” type wear rings.
Renewable Energy Studies
Weston & Sampson evaluated two renewable energy technologies: micro-hydroelectric power (MHP) and solar hot water (SHW) generation. The MHP addressed power generation from the hydraulic head available at the WWTF outfall ,and the SHW addressed pre-heating boiler return water within the anaerobic digester complex.