Demonstrating their stewardship to the environment as well as their commitment to conserve local environmental resources, Dalton Utilities, Dalton, Georgia, has recently invested over $100 million in their city’s wastewater system. Dalton Utilities, founded in 1951, is a municipal agency that is responsible for providing electric, water, wastewater, natural gas and telecommunications services for its 10,400 citizens. Serving as the county seat of Whitfield County, the City of Dalton is known as the "Carpet Capital of the World". The community has a strong economic relationship and history in the textiles industry and was also recently selected as a Georgia "City of Excellence."
The construction and improvement of four wastewater treatment facilities has allowed Dalton to meet the wastewater demands of its customers now and for many years to come. Currently 30-40 million gallons of wastewater are treated on a daily basis. The over 200 miles of gravity-fed piping in their collection system is utilized by residential users as well as heavy industrial usage from local carpet finishing plants. Unique to Dalton Utilities is their operation of one of the world’s largest Land Application Systems that distributes treated wastewater over a 9,200 acre site. Treated wastewater is ground sprayed (pictured at right) and further cleansed by soil and plant life to continue the cleansing process. Serving as a pioneer in this natural way of treating wastewater, Dalton also has the added benefit of creating a natural wildlife habitat in the process.
Integral to the efficient processing of their wastewater flows, is the monitoring of their collection system pipelines. Accurate flow monitoring of these lines allows them to address in a timely manner any maintenance issues including blockages and back-ups that would hinder the flow of wastewater to local treatment facilities. Lamar Womac, SCADA coordinator with Dalton Utilities Wastewater Division states, “With this particular flow application we are monitoring to make sure we do not have a backup of the system that would require our attention. We actually are a small town but we have large businesses in the area. Dalton Utilities services the carpet industry in our area which provides very large wastewater flows.”
When the procurement of new flow meters was needed to replace flow meters that had ‘washed away’ during heavy flow periods, they contacted their local flow rep. Womac comments, “The meters we had been using were supposedly wet-environment type units but when we would get a rainstorm the units would flood and then you’re done. That’s the important time that the meters are needed to record the heavy flow events. That’s what we’re waiting for.”
Due to the problematic issues experienced with submerged style flow meters, Dalton Utility’s Engineering personnel wanted to gather information on the Marsh-McBirney ‘above-the-flow’ flow meter, Flo-Dar. The Flo-Dar Flowmeter measures open channel flow remotely without the need for a submerged sensor which would eliminate the concern that the meters could be swept away by heavily debris-laden flows. The “above the flow” installation also eliminates maintenance and lost data due to sensor fouling. Flo-Dar’s easy installation requires no manhole entry after the initial installation and the sensor can be installed and/or removed from street level eliminating costly confined space entry manpower and equipment costs.
The Flo-Dar sensor transmits a digital Doppler radar beam that interacts with the fluid and reflects back signals at a different frequency than that which was transmitted. These reflected signals are compared with the transmitted frequency. The resulting frequency shift provides an accurate measure of the velocity and the direction of the flow. Level is detected by ultrasonic pulse echo. Flow is then calculated based on the Continuity Equation: Q = V x A, Where Q = Flow, V = Average Velocity and A = Area.
After learning more about the Flo-Dar meter, Dalton Utilities Engineering Group placed an order for five Flo-Dar systems that would be compatible with their SCADA system. Womac states, “Prior to using the Flo-Dar we were using several different types of flow monitoring systems and they weren't stable. Once you got a backflow into the system the force would push it out of the way. With Flo-Dar we didn’t have to worry about that.” He adds, “Currently we have five manholes that we are monitoring ranging in size from 36 inches to 48 inches.”
Concerning Flo-Dar’s accuracy Womac states, “They’re good! We’re happy with the accuracy and we haven’t had any problems with surges. We love the stability and the fact that it can be put in the manhole and it doesn’t have to be checked every day. All that we have to do is check our SCADA system so we don’t have to go by the site and check it to make sure it’s still there and functioning. We have future plans for additional Flo-Dar meters to monitor some 100 manholes in our system.” Flow data from the meters is transferred to Dalton’s central facility, known as the Dalton Control Center.
Now equipped with flow meters that won’t leave their post, Dalton Utilities looks forward to many years of reliable, hassle-free monitoring of their collection system. Through the use of Flo-Dar flow meters, Dalton Utilities can be assured that timely and accurate flow data that will provide the notification they require for any problematic maintenance issues that may threaten the efficient operation of their state-of-the-art wastewater treatment system.