College Run Sewage Pumping Station Upgrade

Key Accomplishments

Johnston Construction Company

• Provided redundant temporary pumping capacity, including a fully installed standby pump for each pump size used so that wastewater service could continue immediately in the event of equipment failure or emergency conditions.
• Maintained continuous operation of Frederick County's wastewater collection system throughout construction. The bypass system included restrained temporary discharge piping, plugs, pumping equipment, temporary power and controls necessary to prevent interruption, surcharging, flooding or sewage spills.
• Performed permanent force-main and process-piping improvements associated with the upgraded pumping station, including new force-main piping, bypass connections, valves and appurtenances. Ductile-iron force-main piping was specified as Class 53.
• Installed a new wastewater comminutor/grinder system to reduce incoming solids and protect downstream equipment. The specified twin-shaft grinder was capable of handling at least 3.7 MGD, or 2,569 GPM, and incorporated stainless-steel guide rails for removal and maintenance.
• The grinder utilized a 5-horsepower, 230/460-volt, three-phase motor with automatic jam detection and reversing functionality. Its controller incorporated PLC-based controls designed to automatically attempt to clear obstructions before placing the unit into a failure condition.
• Integrated the new grinder with the station telemetry system. A dedicated remote alarm circuit was required between the grinder controller, station control panel and station telemetry system so grinder fault conditions could be remotely monitored.
• Installed a new 10-inch electromagnetic wastewater flow-metering system consisting of a Siemens SITRANS MAGFLO MAG 5100 W flow sensor with MAG 6000 transmitter and a specified measurement range of 1,200 to 2,400 GPM.
• Provided modern process-data recording capability through a Siemens SIREC D200-type data logger with analog and digital channels, Ethernet TCP/IP connectivity, USB data logging, touchscreen navigation and password-protected access.
• Coordinated replacement and modernization of the existing station controls, electrical distribution, lighting and instrumentation systems as part of JCC's Prime Contract responsibilities, integrating the new process equipment into the rehabilitated facility.
• Upgraded the station's emergency-power system, including a 200-ampere, 480/277-volt, three-phase, four-wire automatic transfer switch capable of automatically transferring pump-station loads between normal utility power and emergency generator service.
• Provided standby-power fuel storage sized for 24 hours of operation at facility running load. The generator system incorporated a double-wall sub-base fuel tank with containment, fuel-level indication, overfill protection and associated venting.
• Rehabilitated the existing wet-well ventilation system, coordinating mechanical and electrical modifications necessary to improve the operating environment within the existing pumping-station facility. Wet-well ventilation replacement was expressly included in the overall upgrade contract.

B & R Electrical Contractors

• Furnished the labor, materials and tools required for the pumping-station electrical construction, coordinating its work with JCC's overall rehabilitation of the existing wastewater facility and with equipment furnished by other parties.
• Furnished and installed a new Motor Control Center, 15 kVA transformer, Panel LP and required disconnects, establishing the principal power-distribution and motor-control infrastructure required for the rehabilitated station.
• Installed conduit, conductors and electrical equipment for the new electrical service from the existing utility transformer, providing the permanent service connection necessary to support the upgraded pumping-station equipment.
• Installed the JCC-provided standby generator and completed its associated conduit and wiring. BRE's subcontract specifically included installation and electrical connection of the generator while generator fuel, generator testing and removal of the existing generator were excluded from BRE's scope.
• Coordinated the station's normal and emergency power-distribution systems, including the Motor Control Center and associated automatic-transfer-switch requirements contained within the project's electrical specifications. The overall station design incorporated a 200-amp, 480/277-volt, three-phase, four-wire automatic transfer switch serving normal and emergency power.
• Provided conduit and wiring for the new wastewater flow-meter system. The process equipment itself was furnished by others, while BRE's subcontract included the electrical infrastructure and connections required for the flow meter. The specified station flow-meter system utilized a 10-inch Siemens SITRANS MAGFLO MAG 5100 W with MAG 6000 transmitter and a flow range of 1,200 to 2,400 GPM.
• Provided conduit and wiring for the new wastewater grinder/comminutor system, which was furnished by others. The specified grinder was a twin-shaft unit rated for at least 3.7 MGD / 2,569 GPM and incorporated automatic jam detection and reversing control.
• Supported the grinder's remote alarm and telemetry interface through electrical field wiring. Project specifications required a remote alarm circuit between the grinder controller, station control panel and the station telemetry system. BRE's role was the associated conduit, wiring and electrical connections rather than programming the telemetry system.
• Provided conduit and wiring for the upgraded HVAC equipment furnished by others. BRE's electrical scope interfaced the mechanical equipment with the station electrical system, while the HVAC equipment itself and its mechanical installation were expressly excluded from BRE's subcontract.
• Furnished and installed new lighting designed to match the station's existing fixtures, including the associated wiring, lighting components and required electrical support.
• Performed electrical demolition and safety isolation work, disconnecting and making safe existing electrical equipment that was scheduled to be demolished by others as part of the broader pump-station rehabilitation.
• Completed electrical permitting and coordinated required submittals and shop drawings for the electrical systems, including equipment associated with electrical service, grounding, panelboards, dry-type transformers, the Motor Control Center / ATS, service-main circuit breaker and lighting components.
• Coordinated manufacturer testing services and materials furnished by others, allowing electrical connections and equipment interfaces to be completed in accordance with the overall startup sequence.
• Prepared as-built / record drawings and reviewed required O&M documentation as part of project closeout, supporting final turnover of the upgraded pumping-station electrical systems to Frederick County.