Naval Support Activity Annapolis Water Treatment Plant – Water Conservation Project

Key Accomplishments

Johnston Construction Company

• Integrated a new filter-reject-water storage and pumping system to recover and recycle process water rather than discharge supernatant to the POTW.
• Installed new process infrastructure including a solids meter vault, valve vault, recycle-water pump station, thickener-overflow pump station and thickened-solids pump station.
• Constructed and equipped a new centrifuge building incorporating centrifuge dewatering equipment, polymer systems, solids conveying and truck-loading facilities.
• Furnished and installed two bridge-supported gravity thickener mechanisms, including one in a new tank and one as a retrofit to an existing tank.
• Furnished and installed two Lamella® gravity settler systems designed for water-filter backwash service at approximately 550 GPM per unit.
• Coordinated new equipment with the facility's existing SCADA/PLC system, new motor-control-center infrastructure, instrumentation and process controls.
• Performed work within an occupied and operational Naval facility, requiring careful sequencing, utility-interruption coordination, security access and maintenance of ongoing operations.
• Managed required regulatory reviews and permits, including MDE, erosion and sediment control, stormwater management, excavation and other applicable federal, state and local approvals.
• Provided system testing, startup, commissioning support, Government operator training, as-built documentation and O&M closeout materials.
• Dewatering was performed by two new centrifuge systems housed within a new centrifuge building. The facility incorporated chemical polymer conditioning, solids conveying and a dedicated truck-loading area with weighing capabilities for handling the dewatered material. Centrifuge supernatant was returned to the gravity-thickening process, forming part of an integrated internal-recycle approach that reduced the need for external wastewater discharge.
• Construction was performed in an active federal installation under NAVFAC requirements. Work included coordination of planned service interruptions, site security and access requirements, Davis-Bacon wage compliance, environmental protection, quality control and federal safety requirements. Johnston was responsible for obtaining or coordinating applicable regulatory reviews and approvals, including MDE, erosion and sediment-control, stormwater-management and excavation-related permitting.
• Following installation, the project included inspection, equipment startup and testing, commissioning support and Government personnel training. Closeout requirements included as-built drawings, commissioning and system-operation verification records, design documentation and comprehensive operation and maintenance manuals for the installed and modified systems.

Electrical Services Division

• Furnished labor, materials, tools, equipment and supervision for the electrical portion of the NSAA Water Treatment Plant – Water Conservation Project under JCC's design-build subcontract. ESD's subcontract specifically incorporates the NAVFAC/Constellation/JCC contract documents and identifies Constellation NewEnergy as the General Contractor and JCC as ESD's Contractor.
• Installed extensive conduit, wire, boxes, devices and electrical distribution infrastructure throughout the process facilities.
• Furnished and installed new electrical switchgear components associated with the project, including new breakers, transformers and disconnect switches where included in ESD's scope.
• Performed electrical demolition and modifications required to accommodate new treatment-process equipment and systems.
• Installed electrical connections for the new process equipment associated with the solids-removal, thickening, recycling and centrifuge systems.
• Installed approximately 695 LF of electrical heat tracing associated with process piping.
• Installed underground electrical infrastructure, including excavation, backfill and stone encasement for numerous ductbank sections serving the treatment-process facilities.
• Supported equipment inspection, startup and testing associated with the electrical installation.
• Prepared required shop drawings, technical submittals, O&M information and as-built/record drawings in accordance with the project requirements.
• Performed the work within an active federal facility under NAVFAC safety, security, Davis-Bacon and project-specific quality requirements.
• The electrical installation included conduit and wire systems, electrical boxes and devices, equipment connections, distribution equipment and switchgear. Internal estimating records document approximately 9,004 LF of conduit and nearly 59,720 LF of wire across the project, serving equipment and controls throughout the treatment facility.
• ESD also performed substantial underground electrical infrastructure work. Its subcontract included excavation, backfill and stone encasement for multiple ductbank configurations extending between the project's new and existing process facilities. The work supported routing of electrical power and control infrastructure while coordinating with the overall civil and process construction sequence.
• The electrical package included heat tracing for process piping, with the project estimate documenting approximately 695 linear feet of heat-trace installation. ESD also provided electrical inspection and startup support as part of its contracted work.
• The work was performed within an active Naval facility and required coordination with JCC's overall design-build schedule, NAVFAC safety requirements and other trades. ESD was also responsible for project submittals, applicable O&M information, record drawings, and coordination of its work with the design and construction documents incorporated into the subcontract.