Putnam has been under financial pressure since losing its industrial base throughout the late 1970s and early 1980s. Its reduced tax base meant the town was hard-pressed to find the means to move any infrastructure projects forward. When Fuss & O’Neill did its first nitrogen study in 2002 half of the plant was inoperable but construction could not begin until 2010 when economic stimulus funding became available. In addition to
equipment improvements, the facility needed to incorporate low-level nitrogen and phosphorus removal to meet
regulatory standards as well as odor controls to protect the surrounding neighborhood.
Wastewater treatment has been a core expertise of the firm since its founding. Given that the original construction was completed over 40 years ago, the talents of almost every one of the firm’s disciplines was engaged over the course of the project. A landfill and an informal disposal area on site required remediation, as did dated, hazardous construction materials from the plant buildings. Adding capacity and modernizing the plant involved mechanical, electrical and structural engineering. In addition, instrumentation engineers created and installed a new SCADA system and the manufacturing equipment experts designed a sustainable preventive maintenance program.
A complete rebuild of the plant, which would have cost the town an estimated $40 million, was impossible for the Town of Putnam to afford. Instead, innovative re-use of much of the existing infrastructure kept the project cost within the funding level for which the town qualified. The new facility
uses existing aeration tanks retrofitted to provide the four-stage treatment process. Odor control for the sludge handling process, a necessity because of a nearby YMCA and farmer’s market, was achieved through a carbon absorber and FRP flat cover system. In addition, a preventive maintenance regimen was established to keep the facility operating optimally over time.
Despite financial hurdles, changing regulations and numerous changes in town and WPCA leadership, the town remained committed to the new facility throughout the process. Major improvements include influent screening and grit removal, modifications to the primary clarifiers, implementation of the four-stage biological treatment process for nitrogen removal, aeration tank improvements, new secondary clarifiers, UV disinfection and instrumentation for the upgraded processes. The facility achieves a total nitrogen effluent concentration in the range of the3 to 5 mg/L.
Phosphorus removal is achieved by the addition of chemicals to an effluent concentration of less than 0.7 mg/L. The overall Facility
is rated to treat an average-day design flow of 2.3 MGD of domestic and industrial wastewater.