The Metropolitan Sewerage District of Buncombe County, North Carolina (MSD) is soliciting Statements of Qualifications for Professional Engineering Services associated with the Hydroelectric Facility Condition Assessment project. The project includes a condition assessment of all components associated with the Hydroelectric Facility and recommendations for rehabilitation and appropriate upgrades. MSD is a regional wastewater utility serving the greater Asheville, NC area, and serves a population of approximately 201,000 customers. Raw wastewater is conveyed from the collection system to MSD's French Broad River Water Reclamation Facility (WRF) in Woodfin, NC. The plant treats an average flow of 23 million gallons per day and consumes approximately 18.4 GWh of electricity annually. MSD operates a hydroelectric facility adjacent to the WRF that produces electricity and is sold back to Duke Energy's electrical grid. On average, the hydroelectric facility offsets more than 40% of the total electrical demand at the WRF. MSD's Hydroelectric Facility and the Craggy Dam Reservoir (originally named Weaver Dam) were constructed in 1904 for electric generation by the W.T. Weaver Power Company and supplied power to Asheville Electric Power Company to operate the City's street railways. In 1926, Carolina Power and Light Company bought the dam and operated it until 1963 at which time it was deemed uneconomical, and operations were discontinued. Soon thereafter, MSD purchased the hydroelectric dam and power generating facility from Carolina Power and Light Company. During the early phases of construction of MSD's WRF (mid 1960s), State Highway 251 (Riverside Drive) was relocated to the west to expand the plant's allowable footprint. As a result, approximately two-thirds of the existing Hydroelectric Facility's original flume was filled in and abandoned. In 1984, MSD rehabilitated the facility, reconstructed portions of the flume, and began generating power to offset a significant amount of the plant's annual electrical demand. Improvements made during the 1984 upgrade included: Minor crest smoothing on the dam for roughly 30 feet at the east end (dam elevation was not changed).
New concrete flume wall parallel to the riverbank to replace the original flume that was filled in due to State Highway 251 relocation. The new flume wall was connected to the old flume wall approximately 600 feet upstream of the power plant (i.e. approximately 2,200 feet of new flume was constructed).
Installed three new Allis-Chalmers 850kW hydraulic turbines to replace the old units. All new turbines are tube type of the same size and connected to external induction generators through a speed increaser. One turbine is equipped with adjustable blades to accommodate variable flow conditions. During low river flows, the adjustable turbine is typically the only turbine in use. MSD's Hydroelectric Facility is generally comprised of the following major components: Craggy Dam (FERC P-7497), flume intake/gate structure, flume, power plant influent gate structure, and power plant. The length of the flume from the dam to the downstream power plant is approximately 2,800 feet. The power plant houses three (3) horizontal turbine generating units with increasing gearboxes, one (1) hydraulic power unit for influent gate control and actuation of adjustable blade turbine unit, three (3) induction generators, and electrical switchgear and controls. Two generating units are driven by fixed blade turbines and the third unit is driven by an adjustable blade turbine, each capable of generating approximately 850 kW at average or above average flow conditions. For questions regarding the RFQ process, or to review information, please contact Tim Hensley directly at (828) 225-8331, or e-mail thensley@msdbc.org. The Metropolitan Sewerage District reserves the right to reject any and all Statements of Qualifications. The method of Contractor Selection has not been Determined at this time.
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