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System requires dramatically less power to run while simultaneously streamlining upkeep
North Ridgeville is a warm, neighborly and growing city of 32,483 located in Lorain County in Northeast Ohio. It was founded in 1810 and incorporated as a city in 1960. The city is located 15 minutes from Cleveland Hopkins International Airport and 30 minutes from downtown Cleveland. At 25 square miles, it is the largest city in land area and third-largest in population in Lorain County.
The French Creek Wastewater Treatment Plant (WWTP) is wholly owned and operated by the citizens of North Ridgeville. It serves North Ridgeville, Avon and Sheffield through main underground interceptor sewer lines. North Ridgeville took full ownership of the sewer treatment facility in late 2008. The plant services about 12,500 accounts through nearly 300 miles of pipeline, and ultimately returns treated effluent to French Creek.
The WWTP was built in 1975 by the Ohio Water Development Authority and was purchased from the state by the city of North Ridgeville in 1983. While the plant is only a few decades old, North Ridgeville has continually upgraded and maintained its operations. The city has invested millions of dollars to ensure that the plant remains current with technology and in compliance with ever-changing environmental guidelines.
A 12-lamp module of the Wedeco Duron UV system that has been raised by the automatic lifting system and is ready for maintenance.
Although the WWTP is ready to serve its growing customer base well into the future with safe, sanitary and cost-effective treatment of sewage, it was dealing with a dilapidated ultraviolet (UV) system installed in 2000 as its disinfection source. The equipment was very labor intensive.
For example, wiring for the lamps was routed inside the lifting arms. As the wiring aged, it would wear out, causing shorts. It was very difficult to “fish” the wire through the arm. Ballast assemblies were located above the channel and were cooled by a glycol loop. Loop tubing leaked, which made the ballast area slippery. The city also found it difficult to locate replacement parts, as the manufacturer was slowly sunsetting the equipment. Finally, the UV system was consuming a large amount of power as it inched closer to the end of its life.
The city needed to identify a replacement UV system that fit into the same channel, offered low power consumption, and contained a practical ease of maintenance to reduce the amount of labor required for the equipment.
Working closely with the city’s consulting engineer—Jones & Henry Engineers Ltd. of Toledo, Ohio—North Ridgeville selected the Wedeco Duron UV system over other inclined UV systems based on an evaluated bid including a 20-year life-cycle cost analysis due its energy efficiency and the ease of maintenance this system it offered. According to the client, the removal of the old system was fairly straightforward. The existing channel was used, as the Duron UV banks actually are narrower than the existing space. The area where the existing UV system was located was demolished and a new level control gate structure was constructed.
The OptiDose True UV intensity-based control is always seeking opportunities to save the customer power.
The Duron UV system is designed to treat 22 million gal per day (mgd) and can be upgraded to a future peak design flow of 32 mgd by adding an additional UV bank. Wedeco’s UV system not only results in lower capital cost, but also lowers energy consumption. OptiDose—the sensor-based, real-time dose control—monitors operating conditions including flow, UV transmittance and UV intensity. Then, with proven control logic, OptiDose adjusts the energy consumption to the minimum needed to meet dosing requirements so that the right dose is delivered using the minimum amount of energy.
Central to the design is how easily and efficiently the system is maintained and serviced. Obviously, large-scale component replacement has decreased since the Duron system is new. Easy lamp replacement can be conducted while the modules remain in the channel. Dry-top UV lamp access and the compact, integrated lifting mechanism allow safe and ergonomic maintenance, including inspection of the UV sensor—a new task for the operators.
Cleaning is simple and safe thanks to the Duron’s automatic, chemical-free OptiWipe system. Wipers consist of PTFE and FKM rings, which have been proven effective even in waters with high fouling potential.