Wastewater project details unveiled

NORWALK — City officials provided more details on Thursday about Norwalk's wastewater treatment plant upgrade, which could be the most expensive project in city history. Earlier this week, Norwalk's city council approved funding for a major wastewater treatment plant upgrade with a loan from the Ohio Water Pollution Control Loan Fund, making the $20 million project the most expensive in city history, coming in at nearly double the previous record, the renovation of the Norwalk Theatre. The project, focused on the facility on Woodlawn Avenue, will upgrade the rear half of the wastewater treatment plant to increase the maximum wastewater flow to 15 million gallons per day. The front portion of the plant was upgraded in 2006, according to Norwalk Public Works director Aaron Osborn. The project includes: • New cloth media filter system • Rehabilitation of the nitrification tower and existing screw pumps • Addition of another screw pump • Demolition of old digester tanks • New ultraviolet disinfection system • Upgrading the existing digester system • Electrical upgrades, including new backup generators and transformer • New sludge dewatering system • New dry sludge storage facility The changes to the plant will allow the city to meet new environmental guidelines and allow for future city growth, according to Osborn. "The upgrades will accommodate the additional wastewater flow from the Ohio EPA mandated elimination of the Washington and Cline streets combined sewer overflow," Osborn said. "The Washington and Cline Street Interceptor projects were just completed this year." With the increased efficiency of the new cloth media system, the city will be doing its part to protect delicate ecosystems which could be damaged by increased amounts of nutrients. Nutrient removal is important in wastewater treatment because it helps to protect our water resources from nutrient pollution. Excess nutrients in the environment can lead to eutrophication, which is a process that can deplete oxygen levels in bodies of water and leads to killing fish and other aquatic life, according to the EPA. Nutrient pollution can also cause harmful algal blooms, which are large growths of algae that can block sunlight and oxygen from reaching aquatic plants and animals, also leading to their death. Nutrient removal helps to reduce nutrient pollution by removing harmful nutrients from the wastewater before it is discharged into the environment. "The new cloth media filter system also improves nutrient removal, which reduces nutrients that are discharged into the waste stream at the end of the wastewater treatment process," Osborn said. The process of nutrient removal is important because it helps to protect water resources and the plants and animals that depend on them, according to the EPA. According to Osborn, the project will take approximately two years to complete and residents should expect little to no changes in service or traffic due to construction. "Residents can expect to see a lot of construction activity at the wastewater treatment plant and no changes to services," Osborn said. "The plant will continue to operate as usual during construction, this is one of the reasons that water treatment and wastewater treatment plant projects are complex and must be completed in a well-planned and methodical process that will not interrupt operations."