Working alone in New York State, approximately 90-100 miles south of Rochester and Lake Ontario, plant operator Chuck Wright depends on the good performance and reliability of the equipment he diligently looks after near the Village of Addison. With such a high level of responsibility, the beauty of well-engineered, low maintenance equipment cannot be underestimated – and following a USD 3.34M upgrade to bring the 34-year-old treatment facility up to code and meet New York State Department Environmental Conservation (DEC) requirements, Chuck is rightly proud of the clean and well maintained Addison Wastewater Treatment Plant.
The Village of Addison had retained emerging national architecture, engineering, and survey firm Larson Design Group (LDG) for design and construction services, developing the project scope and funding applications for rehabilitation of the anaerobic digester unit, replacement of a wastewater pumping station, installation of a stand-by emergency generator and a mechanical bar screen. Other improvements under LDG’s contract included the major task of replacing the clarifier internals, as well as raw wastewater pumps, trickling filter recirculation and HVAC upgrades. Larson Design Group has also provided engineering services for the Village’s water supply and treatment system, local streets and drainage problems within the Village. Amidst the substantial improvements, two pieces of equipment that have very steadily kept on doing their job at the (average) 220,000 gallons per day (420,000 permitted) plant are a Spiraflo Clarifier and a Raptor Fine Screen, which were both supplied by Lakeside Equipment Corporation in 2008.“I do my best to keep everything clean and running smoothly”, said Chuck Wright at Addison, “but I have no problems at all with the clarifier or the screen. Apart from occasional oil changes and a few squirts of grease, these keep working very well” He added: “Compared to some pieces of equipment, Lakeside’s seals and bearings are of exceptional quality. Nothing gums up or clogs. The Raptor Fine Screen does a great job getting rid of the paper and heavier particles before they can get to the clarifier”.
The Lakeside Spiraflo Clarifier was retrofitted into the existing concrete structure to replace an old center-feed peripheral take-off clarifier that performed poorly due to short-circuiting. With the new peripheral-feed center take-off Spiraflo Clarifier, Chuck Wright certainly doesn’t have to worry about short-circuiting because its spiraling flow pattern flows around the baffle skirt and under the skirt to ensure maximum use of the entire tank volume (26-feet diameter – and shallow 8.5-feet depth). This is in contrast to a typical center-feed clarifier flow pattern that is subject to the waterfall effect and sludge wall creep, which allows the influent to short-circuit directly to the effluent weirs, allowing solids carry over. The center-feed flow pattern flows counter-current (outward), compared to the sludge scraper that is moving solids inward to the sludge draw-off pit. This short-circuiting prevents complete use of the tank volume for the settling process. Conversely, wastewater enters the Spiraflo Clarifier at the periphery of the tank and is directed along the narrow raceway.
