Mattawoman WWTP Building 22A Doorway Expansion

Key Accomplishments

• Performed structural modifications to the existing masonry wall assembly to create the enlarged roll-up door opening. The work included masonry removal and installation of a new structural lintel above the modified opening, with the lintel furnished by Johnston Construction Company and the masonry activities coordinated through JCC’s specialty masonry subcontractor.
• Managed construction within an existing wastewater-treatment facility while protecting ongoing plant operations and surrounding infrastructure. Contract requirements called for construction activities to avoid interference with the normal use of existing structures, roads, utilities and other operating facilities.
• Provided the temporary construction protections required to safely perform the building modification, including staging, barricades, platforms, guards and other protective measures necessary for workers, County personnel, existing facilities and the surrounding work area.
• Coordinated project mobilization, equipment and material delivery, site setup and final demobilization. The contract required mobilization to begin within fourteen days of the Notice to Proceed and required all temporary equipment, tools and materials not forming part of the permanent construction to be removed following completion.
• Completed the doorway modification under a 60-calendar-day contract duration, requiring coordinated procurement, masonry demolition, structural work, installation activities and project closeout within the County’s established construction schedule.
• Maintained project record documentation and prepared final redline/as-built information for County review. Approved redline drawings were required before the County would proceed with the final inspection of the completed work.
• Completed cleanup and restoration following construction, removing temporary facilities and surplus materials and leaving the Building 22A work area in a clean, orderly and safe condition acceptable to Charles County.
• Johnston Construction Company served as the Prime Contractor for the Mattawoman Wastewater Treatment Plant Building Doorway Expansion project for Charles County Government. The work was performed at Building 22A of the Mattawoman Wastewater Treatment Plant, 5310 Hawthorne Road, La Plata, Maryland. The project was administered through Charles County Government’s Department of Public Works – Utilities Division.
• The primary purpose of the project was to modify the exterior of Building 22A by increasing the height of the existing front roll-up door opening. Rather than construction of a new building, the project required modifications to the existing structure so the larger doorway could be incorporated into the operating wastewater-treatment facility.
• JCC was responsible for coordinating, scheduling and supervising the complete construction effort and furnishing the labor, tools, equipment, materials and supplies necessary to perform the doorway expansion. The project was executed as a lump-sum construction package in accordance with the County’s drawings, contract documents and applicable Charles County construction standards.
• A key component of the building modification involved the existing masonry surrounding the doorway. JCC coordinated the required masonry removal and installation of a new lintel to permit the roll-up door opening to be increased in height. The specialty masonry portion was subcontracted to Matthews & Pierce Masonry, Inc., while Johnston Construction Company furnished the lintel and remained responsible for overall coordination of the prime contract.
• Because the work was performed within the existing Mattawoman Wastewater Treatment Plant, construction activities had to be managed without unnecessarily interfering with the normal use of existing structures, roads, utilities or plant facilities. JCC was responsible for maintaining a safe and orderly work area and providing the barricades, staging, platforms, guards and other temporary protections required during construction.