LocationBoyds / Clarksburg area, Montgomery County, Maryland
MarketWater Storage and Tanks
SITE DEVELOPMENT, 16-INCH WATER MAIN, ALTITUDE VALVE VAULT, DRAINAGE, OVERFLOW PIPING, ELECTRICAL TRENCHES AND SITE RESTORATION.
Johnston Construction Company
- Performed the major civil site-work and utility package supporting construction of WSSC's new 1-million-gallon composite elevated water storage facility. The overall project included the elevated tank and foundation, piping and valves, vaults, site development, grading, access improvements and stormwater-management infrastructure.
- Provided and maintained the project's erosion and sediment-control systems and completed preliminary site development, including installation of required controls, stabilized construction access, clearing and grubbing, removal of resulting debris and coordination of required environmental inspections throughout the civil construction period.
- Constructed the site drainage and tank-overflow infrastructure, including drainage piping, precast structures and the tank overflow drain system. JCC's scope also included continuation of the tank's 4-inch floor-drain piping outside the foundation and construction of the associated French-drain system.
- Installed the new 16-inch water-main system and associated appurtenances connecting the elevated storage tank to WSSC's distribution system. The overall facility design connected the new 16-inch main to an existing 24-inch water main, with the tank operating in WSSC's 760A/B pressure zone.
- Completed the tank-site water-main connections and associated valve work, including the connection to the existing system, blow-off assembly, ductile-iron tank stub-out connection and flexible joint coupling required to integrate the new elevated tank with the distribution network.
Concrete Services Division
- Performed the specialized cast-in-place concrete package for the altitude valve vault serving WSSC's new 1-million-gallon Clarksburg Elevated Water Storage Facility. The completed vault formed a key component of the new water-storage system because the altitude-valve arrangement controls filling and draining of the elevated tank within WSSC's 760A/B pressure zone.
- Completed concrete forming and placement for the principal components of the altitude valve vault, including the sump slab, bottom slab, structural walls, top slab, concrete topping and concrete pipe supports. CSD's subcontract also included the concrete pipe support associated with the project blow-off piping.
- Executed approximately 81 cubic yards of concrete placement across the contracted vault components, including approximately 38 CY of slab-on-grade concrete, 26 CY of wall concrete, 14 CY of supported-slab concrete and 3 CY of miscellaneous fill concrete.
- Constructed approximately 2,088 square feet of concrete formwork, consisting of approximately 211 SF of slab-on-grade forms, 1,395 SF of straight-wall forms, 466 SF of supported-slab forms and 16 SF of special forming. The work required the forms to be fabricated, erected, stripped and maintained in accordance with the project's concrete and formwork requirements.
- Performed the complete concrete-finishing sequence across approximately 3,449 square feet of finished surfaces. The documented work included approximately 1,260 SF of float-and-screed finishing, 312 SF of floor-hardener work and 1,877 SF of pointing and patching, providing the finished concrete surfaces required for the vault structure.