New Design Water Transmission System. Frederick County, Maryland.
The new potable water transmission infrastructure is known as the New Design Water Transmission System, and consists of approximately 15 miles of large diameter pipeline (42, 36, 30 and 24-inch mains), a water storage tank, and a booster pumping station.
WRA provided project engineering for all aspects of the project, including detailed alignment studies; comprehensive hydraulic and surge modeling, including water quality studies; extensive environmental permitting including Federal NEPA compliance; investigation of various pipe materials for the transmission main; design of trenchless crossings of major highways and railroads; final design and bidding services; and construction services, administration, and on-site inspection. The water transmission pipeline was bid and constructed under four separate contracts, and all are currently completed and in service.
WRA provided information about CSXT’s infrastructure and utility crossing requirements, determining where the pipeline could cross CSXT’s right-of-way without interfering with CSXT infrastructure, preparation of the crossing application, and reviewing contractors’ methods for compliance with CSXT requirements.
The proposed alignment was mapped using photogrammetric aerial methods tied to the Maryland State Plane Coordinate System NAD 83 and NAVD 88 bench marks. Boundary surveys were conducted and used in delineating easement areas, and easement plats were created as needed.
WRA provided geotechnical services for the initial studies through final construction, including a geotechnical boring program. The project is located in the Frederick Valley, which is underlain by a karst landscape and is characterized by sinkholes.
Power for transmission main valve vaults was obtained from the utility company at 208/120V, 3-phase. The power panel was provided with a main breaker, branch breakers and surge protection. The branch breakers serve valve actuators, motors, lights, receptacles, and instrumentation.
Water Transmission and Distribution
WRA civil engineers provided extensive planning and hydraulic modeling in order to properly size the transmission main for ultimate flow conditions, check water age, and determine connection points to the existing water distribution system.
WRA provided full time construction management and inspection staff to monitor the activities of four simultaneous construction contracts. WRA field personnel overseeing the construction included a Resident Project Representative, an Office Engineer/Senior Inspector, and two additional Inspectors.
WRA’s traffic group developed detailed traffic control plans to install the water transmission main along Route 85 as well as County roadways, which included coordination with both Frederick County DPW and MSHA officials.