Wastewater Treatment Plant ENR Upgrades

In 2004, the Maryland Department of the Environment began an initiative to upgrade all of the state’s wastewater treatment plants with Enhanced Nutrient Removal technology in order to increase the quality of effluent discharged into the Chesapeake Bay. More than 65 major plants were targeted for extensive renovation projects aimed at reducing the amount of nutrients, specifically phosphorous and nitrogen, that discharge into local waterways. Carroll Engineering has provided civil and structural designs for ENR upgrades at 13wastewater treatment plants in Maryland, including current projects at the Woodstock Plant in Howard County and the Elk Neck and Perryville Plants in Cecil County. Projects typically include an assessment of existing facilities and processes, as well as designs to upgrade or replace equipment and underground infrastructure. We have provided plans for pump stations, vaults, sludge blending tanks, clarifiers, reactors, filters, and pipe conveyance systems.


  • CEI has provided designs for ENR upgrades at 13 wastewater treatment plants, including: Patapsco, Back River, Camp Frettard, Harbour View, Oxford, Hampstead, Freedom District, Chesapeake Beach, the Maryland Correctional Institution, Joppatowne, Woodstock, Perryville, and Elk Neck.
  • Structural designs typically include large reinforced concrete tanks, pile foundations, air piping, waterproofing, and mechanical storage structures.
  • Civil designs typically include routing of large underground pipes, stormwater management and erosion/sediment control, and Chesapeake Bay Critical Area permits.