Charlotte Hall 0.4 MG Spheroidal Elevated Water Storage Tank

Key Accomplishments

Johnston Construction Company

• Provided project mobilization and the required Charlotte Hall base-bid site work associated with the water tower and water station.
• JCC performed erosion and sediment-control work, including measures to maintain positive site drainage and protect prepared subgrades from saturation during construction.
• Coordinated construction staking, geotechnical evaluation and field testing associated with the tank foundation and site development.
• Constructed the water-tower foundation in accordance with Caldwell's Issued-for-Construction foundation design, including installation of anchor bolts furnished for the tank structure.
• Performed the Charlotte Hall foundation earthwork in accordance with the project geotechnical requirements, including excavation, proofrolling of prepared subgrade, removal and replacement of unsuitable material where required, placement of geotextile and a minimum 8 inches of compacted aggregate backfill over the accepted subgrade.
• Maintained the tank-foundation excavation in a drained condition and coordinated foundation preparation with the project Geotechnical Engineer.
• Constructed the foundation to support a 400,000-gallon elevated tank with a nominal 27.17-foot pedestal base and a specified top-of-foundation elevation of approximately 174.5 feet.
• Executed the foundation work to a design developed by the tank manufacturer in accordance with AWWA D100, ACI 318 and the project geotechnical recommendations, with concrete construction governed by ACI requirements.
• JCC provided the site piping and mechanical work associated with the Charlotte Hall Water Station, including valves, fittings, manholes, accessories and other components necessary to complete the piping systems shown on the project drawings.
• Installed underground water-station piping associated with the project, including 10-inch and 4-inch PVC water mains and valves included in the Charlotte Hall Water Station requirements.
• Performed required piping testing and sterilization-related work, including supporting documentation and coordination with Caldwell and the Owner.
• Supported integration of the new 250 GPM well, constructed under a separate contract, into the Charlotte Hall Water Station and its associated control systems.

Concrete Services Division

• Performed specialized formwork, concrete placement, finishing and curing for the tank foundation in accordance with the project drawings, concrete specifications and Caldwell-issued foundation requirements.
• Completed approximately 2,332 square feet of concrete formwork associated with the foundation, slab-on-grade and curved-wall construction.
• CSD constructed the curved foundation-wall formwork, representing the largest single formwork component of the subcontract, together with footing and slab-edge forming.
• Furnished the labor, form materials and related equipment required for footing forms, slab-on-grade forms and curved-wall forms, including rental and purchase of form systems as required.
• Placed approximately 146 cubic yards of concrete across the footing, slab-on-grade and curved-wall elements of the tank foundation.
• Performed concrete placement for approximately 71.8 cubic yards of footing concrete, approximately 30 cubic yards of slab-on-grade concrete, and approximately 44.7 cubic yards of curved-wall concrete.
• CSD performed approximately 3,863 square feet of concrete finishing work, including float/screed finishing, machine troweling, point-and-patch finishing and localized bag finishing.
• Completed approximately 4,338 square feet of concrete curing work, including curing labor and associated curing supplies.
• Furnished and installed concrete accessories associated with the foundation work, including vapor-barrier installation, premolded joints, saw-cut joints and joint sealing within CSD’s subcontract responsibilities.
• CSD set the tank-foundation anchor bolts in coordination with Johnston Construction Company and Caldwell’s tank-foundation requirements.
• Provided concrete-form stripping and removal labor following achievement of the required placement and curing milestones.
• Provided labor for winter-protection installation and coordination where required, with blankets and heaters furnished through JCC under the subcontract division of responsibilities.
• Coordinated concrete pumping activities, concrete testing and inspection requirements with Johnston Construction Company while concentrating CSD’s field scope on concrete forming, placement and finishing.
• Performed concrete accessory labor involving construction joints and sealing necessary to complete the foundation concrete work.