Julie Brooks, Bellefonte Borough Public Works
The Bellefonte Borough wastewater treatment plant serves the residents and businesses of Bellefonte Borough and portions of Spring, Benner, and Walker townships. The Spring Benner Walker Joint Authority operates its own collection system, which conveys wastewater to the Bellefonte Borough wastewater treatment plant for processing. Bellefonte Borough employees staff the wastewater plant and Bellefonte Borough public works crews maintain the wastewater collections system within the Borough limits. The Bellefonte Borough wastewater treatment plant staff also administer and maintain the U.S. Environmental Protection Agency (EPA) approved industrial pretreatment program for the service area.
Photo 1. The daily flow to the plant averages 1.8 MGD (Million Gallons per Day) and the plant is rated for a maximum of 4.5 MGD, based on design and holding capacity.
Current Bellefonte Borough wastewater treatment plant processes begin with influent flow to a bar screen and a fine screen with additional grit removal. Plant influent then moves to equalization basins which provide mixing and add holding capacity during high flow conditions. From these mixed basins, influent flows return and enter the Activated Sludge units. Fine powdered magnetite mixed to a slurry is added into these units to aid sludge formation and settling. The magnetite is recovered and recycled back into the Activated Sludge units as sludge is removed from these units. The Activated Sludge units break down solids by biological processes in anaerobic (in absence of oxygen) and aerobic (in presence of oxygen) conditions. Then the sludge is transferred to an intermediate aerobic digester. Sludge solids are thickened with the addition of polymer in the thickener and moved to large final digesters for further biological breakdown and pH adjustment. Biosolids from the digesters are then dewatered and stored on site. Effluent liquid from the Activated Sludge units moves to a clarifier where more solids settle and a carbon source is also added to aid nutrient removal in the next step, the Biological Nutrient Removal (BNR) filters. The last treatment process is Ultraviolet disinfection followed by final discharge of the treated effluent into Spring Creek. The plant treatment processes work extremely well. Average removal rates for conventional pollutants are 97% to 99%.
The plant discharges an average of 2 million gallons per day of treated water. Solids are also generated from the plant treatment process; these dried solids average 410 tons per year. These biosolids meet EPA Class A requirements for pollutant levels and EPA Class B requirements for pathogen reduction as listed in EPA part 503 Biosolids rule. All of the treatment plant solids are spread on local crop land, under an Agricultural Utilization General Permit. These biosolids recycling sites encompass roughly 479 acres on five separate farms, all within ten miles of the wastewater treatment plant. The biosolids are dewatered at the plant and stored on-site until land applied by plant personnel. All required personnel are certified by the Pennsylvania Department of Environmental Protection in biosolids handling. Recycling biosolids as a soil amendment is one of the most sustainable options for biosolids handling and has benefits for enhancing soil health. Biosolids used as a soil amendment recycle nutrients and reduce chemical fertilizer use on farms. Biosolids also increase soil micronutrients like zinc, iron and copper not often readily available in commercial fertilizers.
Photo 2. Bellefonte Borough wastewater treatment plant serving Bellefonte and surrounding areas.
About the author: Julie Brooks has a master's degree in public administration and is a certified water and wastewater plant operator with many years of experience in municipal operations at all levels. She has served Bellefonte Borough as the Wastewater Treatment Plant Assistant Superintendent and is currently Assistant Superintendent of Bellefonte Borough Public Works.