Harrisburg, Pa. — The American Council of Engineering Companies Maryland presented Gannett Fleming with an Outstanding Project Award for Maryland American Water’s Bel Air Impoundment project during the 2019 Excellence in Engineering Awards on Feb. 21.
The Bel Air Impoundment is the largest dam project in Maryland in 30 years and sets new standards for the design of water storage reservoirs. Securing a reliable water supply for more than 14,000 residents, the new system features a 62-foot-high earthen embankment with a 20-foot-wide crest and can store up to 90 million gallons of raw water.
“The engineering and construction management services provided by Gannett Fleming were critical to the overall success of the impoundment project,” said Barry Suits, Maryland American Water president. “This project represented a true partnership between Maryland American Water, local and state officials, and Gannett Fleming to create a safe, reliable water supply solution for our customers that serves as a model for water sustainability.”
Winters Run, the river that runs through Harford County and the main source of water for Bel Air, does not provide an adequate water supply during times of drought as required by the Maryland Department of the Environment. For more than 20 years, Maryland American Water purchased additional water as needed from Harford County, but the county’s water supply was never a viable, long-term solution.
The raw water impoundment fills with water from Winters Run when stream flows are adequate and provides an essential back-up water supply for the Bel Air community when there is a need for a secondary supply. Now in service, the impoundment can provide approximately 1 million gallons per day of additional water supply.
The Gannett Fleming design team selected a bituminous geomembrane (BGM) liner to create a watertight barrier along the 2,025-foot-long dam embankment and impoundment floor. The Bel Air Impoundment project marks only the second time a company used a BGM liner to cover a dam embankment in the U.S. The BGM liner enabled the use of an exposed liner system, eliminating the need for soil cover, which reduced construction costs by an estimated $450,000.
The facility uses leading-edge, sustainable, water-quality improvement systems to clean stored water before it flows to the treatment plant, boosting the plant’s efficiency, increasing the service life of treatment filters, and enhancing drinking water taste and odor. The standard method of improving raw water involves the use of chemicals, which requires careful monitoring and can kill fish and other wildlife through over application. Natural systems eliminate fish kills and reduce chemical usage and related costs by an estimated 20 percent.
Completed seven weeks ahead of schedule, the Bel Air Impoundment project serves as a model of innovative water infrastructure design, while creating a sustainable water supply to meet community needs — now and in the future.