Casne Engineering designed the power, controls, and telemetry for this combined stormwater/sewage station. Pumping for a wide range of flows from .3 - 14MGD are designed. The design consisted of a wet well and dry well for the pumps constructed as a caisson. Two 250hp and two 125hp pumps are driven with variable frequency drives and pump into dual 20-inch pipelines at high flow, each with motorized control valves. A constant speed 40hp pump is provided for low flows. Dual utility feeders are provided for power reliability and pumps are provided with fly wheels to dampen the hydraulic surges from loss of power. The divided wet well is fitted with dual bubblers for level control with back-up float switch control. Telemetry is provided over the local cable system to the Rock Creek Wastewater Treatment Plant.

Casne Engineering designed the power and control system upgrades of the two existing pump stations. Three new 50hp variable frequency drives were provided with bypass and isolation contactors in motor control center construction to replace the existing drives. A new ultrasonic level transducer was provided for level control and the existing bubblers were kept for back-up control. Controls were implemented using Allen-Bradley SLC 5/05 with a Panel View 1200 operator touch screen. Telemetry was provided by networking the programmable logic controllers over fiber optic cables run on overhead utility poles to the wastewater treatment plant.

Casne Engineering developed the electrical power and controls for the District's two types of standard wastewater pump stations. The larger type consists of a wet well and dry well with an electrical room above. The dry well is provided with ventilation, motor disconnects, local control switches, trouble switch, lighting, smoke detection, and hazardous gas detection. The control panel is provided with control switches, indication and alarm lights, and level control including type level control with back-up float switches. The standby generator is sound attenuated to a very low level and the building is an attractive split block for locating in residential neighborhood.

Casne Engineering designed over eight of these pump stations. The smaller standard wastewater pump stations consists of submersed wet well pumps with level controls and back-up float control. An outdoor power and control panel consists of pump starters and controls in an “enclosure within an enclosure” with heating and cooling for the programmable logic controller and remote telemetry unit using licensed-frequency radio communication.

Casne Engineering designed the power, controls instrumentation, and supervisory control and data acquisition (SCADA) system for the treatment plant upgrades. The power system consisted of extending the 12.47kV feeder, placement of a new 1000kVA transformer and primary switch, and a 1200 amp, 480V service with dual automatic transfer switches. The plant processes upgraded a new influent pump station, new headworks with grit collection and screening, upgraded oxidation ditch aerators and mixing, clarification, and UV (ultraviolet) disinfection. The solids stream included a new aerobic digester, relocated sludge belt thickener, new belt filter press, and truck loading.

The control system consists of three PLCs networked with fiber optic cable using Ethernet TCP/IP communications to the SCADA computer. Casne Engineering, Inc. programmed the PLCs and configured the graphic screens, database, and alarming, using Wonderware Intouch human-marchine interface, and Win 911 alarming running on a Windows NT platform.