Fort Meade Water Treatment Plant Flocculation and Sedimentation Basin Covers

Key Accomplishments

Johnston Construction Company

• JCC provided the design, fabrication, delivery, and installation of basin-cover systems for the existing flocculation and sedimentation structures.
• The cover systems were designed for structural performance, durability, weather resistance, safe access, and compatibility with the existing water-treatment process and concrete basin structures.
• The covers were designed to open and close as required for inspection, maintenance, and continued operation of the treatment equipment.
• Access hatches and ventilation openings were incorporated into the cover systems to support safe access and operating requirements.
• JCC provided new walkways and handrails needed to safely access the covered basins and associated operating areas.
• Existing handrails and walkways conflicting with the new cover installation were removed and disposed of as required.
• The project included removal and disposal of eight existing mixers from the concrete basins.
• JCC patched openings and voids remaining after mixer removal and restored affected concrete surfaces.
• A structural evaluation of the existing concrete was performed to confirm that the basin walls and supporting structures could safely accommodate the proposed cover loads.
• JCC coordinated the cover design with the condition, geometry, elevations, and structural capacity of the existing flocculation and sedimentation basins.
• Exhaust fans were provided for the covered basin areas to support ventilation and safe operating conditions beneath the new covers.
• Electrical power for the exhaust fans was extended from an existing distribution panel located within the Water Treatment Plant electrical room.

Electrical Services Division

• Electrical Services Division performed the electrical construction associated with the new flocculation and sedimentation basin-cover systems at the Fort Meade Water Treatment Plant.
• The overall design-build project provided protective covers over the existing treatment basins to prevent bird droppings, rainwater, leaves, debris, and other contaminants from entering the potable-water treatment process.
• ESD furnished the labor, materials, tools, supervision, conduit, wiring, boxes, devices, and electrical connections required for the basin-ventilation equipment.
• The electrical scope supported four Cook Fiberglass 245FCP fans, each rated at 10 horsepower with a full-load current of approximately 14 amps.
• Two fans served each sedimentation basin to provide ventilation beneath the newly installed cover systems.
• ESD installed approximately 350 linear feet of electrical distribution from the existing power-distribution panels located on the first floor of the Water Treatment Plant.
• The electrical route extended from the first-floor panels through the second floor and filter-room areas before exiting the building and continuing overhead to the four fans.
• ESD coordinated the installation around the existing Water Treatment Plant structure, operating equipment, basin-cover supports, walkways, handrails, and treatment processes.
• The work included conduit installation, conductor installation, electrical boxes and devices, equipment terminations, and associated supports.
• ESD performed limited electrical demolition necessary to connect the new ventilation equipment to the existing distribution system.
• The scope included excavation and ductbank-related work where required by the electrical routing and installation conditions.
• ESD coordinated its work based on the availability of spare breaker spaces within the existing power-distribution equipment.
• Electrical work was performed within an active water-treatment facility and required coordination with plant operations, JCC, the cover-system installer, equipment suppliers, and other construction trades.
• ESD’s work provided the electrical infrastructure needed to ventilate the newly covered flocculation and sedimentation basins and support safe plant access and operation.

Additional project details

• The purpose of the project was to protect the Water Treatment Plant’s existing flocculation and sedimentation basins from bird droppings, rainwater, leaves, debris, and other contaminants that could enter the open treatment structures.