Drinking water for the members of the Fort Detrick, Maryland community is now cleaner than ever, thanks to ultraviolet light.
In April 2016, the U.S. Army Corps of Engineers, Baltimore District, finished extensive renovations to the Fort Detrick water treatment plant, which included the installation of a stand-alone ultraviolet system (UV) for disinfection. The upgraded system also represents the first-ever stand-alone UV system in state of Maryland.
“This $16.1 million renovation and upgrade took the plant from a fully manual operation, with technicians turning valves and adding chemicals and taking samples for quality analysis, to a computer-networked controlled system to deliver volume based on usage and demand,” said Project Manager Will Hettchen.
The project included updated sludge handling and chemical treatment processes, a water quality testing laboratory, administrative spaces, sludge dewatering equipment and a new chemical storage building. It also repaired and replaced tanks, basins, pumping systems, and piping to improve efficiency and reliability.
Originally built in the 1940s, Baltimore District engineers estimate that this project is the 10th upgrade to the facility that takes raw water from the Monocacy River to support Fort Detrick.
From the river to the tap on Fort Detrick, water is captured and flows through screens at the water intake area to filter out the larger debris items. Moving along the system via new pumps and pipes, the raw water goes through a point where carbon dioxide is added to adjust the water so that the chemicals work properly together. “This is the first of several points in the process where computers monitor the water chemistry and quality, and make adjustments,” said Mark Lewis, Fort Detrick water quality program manager. “Water is sampled throughout the plant by automatic equipment and by trained technicians using lab equipment, and by independent test labs,” noted Lewis.
Water flows through a pre-sedimentation basin to settle out large/heavier material. Coagulant chemicals are then added to the water and slowly churned by paddles in tanks to bind debris into larger particles in a treatment process called flocculation. The water then flows through sedimentation basins and the particles settle out prior to final filtration. Now called settled (but still raw) water, it is monitored and sent into piping for UV disinfection to kill any remaining microbes. Chlorine is then added to ensure residual disinfection for delivery to the customer. Water is also treated with fluoride for dental care and zinc orthophosphate for corrosion control.
To get to the tap, the water is sent by huge pumps into the garrison water supply system. In addition, Hettchen noted, the plant output can be increased from minimal to maximum in minutes versus hours and still maintain water quality. The plant is rated at 2.6 million gallons per day.
“One of the big improvements is in sludge handling,” noted Hettchen. “Sludge is the sediment that is removed from the water during treatment. The old plant produced ‘soupy’ sludge that needed to be mixed with dry material before it could be disposed in the landfill. The new plant produces very dry sludge, which means less trips to haul and less effort to dispose - and less cost.”
As with every Baltimore District project, this upgrade was a team project including Area Engineer Brad Funt, Resident Engineer Pat Welker, and Project Engineer Bill Conroy.
“The new plant operations can account for any river water condition and apply the necessary chemicals to efficiently treat raw (river) water so that it meets and/or exceeds Maryland Department of the Environment and Environmental Protection Agency-mandated levels for clarity, taste, and potability,” said Paul Loeber, who served as the day-to-day construction representative overseeing the work. “The plant is designed to treat raw water with the correct chemicals based on season, water temperature, and climatic conditions.”
Not only was the plant outdated, it needed to support a growing garrison community. In 2017, the U.S. Army Medical Research Institute for Infectious Diseases (USAMRIID) will be completed and become part of a huge complex known as the National Interagency Biodefense Campus. Several thousand workers will be consolidated from multiple locations into the USAMRIID and other facilities. The Fort Detrick garrison and interagency planners worked for years to fund and build the campus. Modern and effective water supply is a key component.