Laserfiche WebLink
Page 2 of 3 <br /> "The wastewater plant is an activated sludge extended aeration plant.The plant was <br /> overloaded and was barely able to handle the incoming flow.The plant staff was not using <br /> any process controls for sludge wasting. Instead,they were estimating when wasting needed <br /> to be done—and land application of the plant's waste wasn't being done,"said Rusty <br /> Whisenhunt, project manager for Severn Trent Services. "This resulted in sludge levels in <br /> the clarifier that were at least five times what was optimal.The mixed liquor suspended <br /> solids (MLSS) count was about 10,000 mg/L,compared to a normal count of 2,500 mg/L. <br /> And the plant was processing only about 1 mgd of wastewater." <br /> Within three months of taking over operation of the plant, Severn Trent Services staff <br /> instituted proper controls and increased the plant's operating capacity back to the plant's <br /> design capacity.The filamentous bacteria(Nocardia amarae)that had formed on the <br /> surface of the wastewater basins were no longer present, and the MLSS count was being <br /> maintained at 2,500 mg/L.As a result,two of the plant's three clarifiers were no longer <br /> needed and were taken of8ine. <br /> Improving Drinking Water Quality <br /> The quality of the city's drinking water, processed by the Clinton Lake treatment facility, also <br /> needed to be addressed.Turbidity rates were typically .2 to .25 NTU. Plant personnel <br /> determined that the automatic chlorine dioxide pre-oxidant system was not operating <br /> properly, enabling algae growth.Once the problem was identified, plant personnel restarted <br /> the system and adjusted the dosage rate.Working with various vendors,they were able to <br /> determine a better alum and cationic polymer blend. Once the proper blend was <br /> implemented,turbidity from the effluent filters was reduced to .05 NTU. <br /> To solve the problem of long detention times in the water treatment system, as well as low <br /> total chlorine residuals that the system had experienced, Severn Trent Services personnel <br /> have identified a location for automatic flushing equipment,a SCADA system and <br /> supplemental chloramine injection locations.These actions will help the city remain in <br /> compliance with ODEQ regulations and with the U.S Environmental Protection Agency's <br /> Stage 2 Disinfection Byproducts Rule. <br /> Significant Energy Savings <br /> The wastewater plant and the Clinton Lake water treatment plant, combined, are the city of <br /> Clinton's largest user of electricity,so any reductions in energy usage at the plants was <br /> welcomed. Once Severn Trent Services had implemented efficiencies throughout the two <br /> plants—including, importantly, shutting down the two small clarifiers—energy use was <br /> reduced by 45%to 50%. <br /> According to City Manager Grayson Bottom, regulatory compliance was the number one <br /> priority in bringing in a public-private partner.After nearly three months of working with <br /> Severn Trent Services, Bottom said an ODEQ representative visited the plants and was <br /> "absolutely radiant." <br /> "The government official told Clinton representatives that the plants"had exceeded every <br /> expectation they had," Bottom said. <br /> Severn Trent Services <br /> Suite 300 <br /> 580 Virginia Drive Fort Washington, PA 19034 <br /> P:215.997.4058 <br /> F:215.997.4062 <br /> erisch(a)severntrentservices.com <br /> www.severntrentservices.com <br /> Copyright 02011 Scranton Gillette Communications Inc. <br /> 3030 W. Salt Creek Lane, Suite 201 <br /> Arlington Heights, Illinois 60005-5025 USA <br /> 3/25/2011 <br />