Wastewater Treatment Plant
The South Huron Valley (SHV) Wastewater Treatment Plant (WWTP) is an A/O biological phosphorus removal (BPR) treatment plant. It was originally constructed in 1986 with a design capacity of 12 Million Gallons per Day (MGD) and was expanded in 2000 to 24 MGD design capacity. The peak influent pumping station capacity is 55 MGD (firm); the primary capacity is also 55 MGD (firm). The secondary capacity is 24 MGD design, 32 MGD peak 24-hour, and 38 MGD peak hourly. An equalization tank with a capacity of 6 million gallons was added in 2006. The sodium bisulfite dechlorination facilities were added in the early 1990s, and the liquid chlorine disinfection facilities were converted to sodium hypochlorite disinfection in 2012, primarily for safety reasons.
The original solids treatment scheme was to thicken and haul to the Downriver WWTP for further processing and disposal. However, that practice was abandoned in 1999 in favor of lime stabilization (to a Class B biosolids), storage (via 4 Million Gallon Haag tank installed in 2000), and land application of liquid biosolids by Earth Tech. The solids process is being evaluated under a companion report – Long-term Biosolids Evaluation.
A short Video of the Wastewater Treatment Plant
Plant Pictures
Outfall
An 84-inch diameter outfall sewer from the WWTP travels 6,987 feet underground to the shoreline of the lower Detroit River within the Lake Erie Metropark located at the end of Lee Road. From there, a 78-inch diameter outfall sewer extends 6,300 feet offshore into the southern reaches of the Detroit River. The underwater portion of the outfall (6,300 feet) was placed by divers in 40 foot sections and required the blasting and removal of 120,000 cubic yards of rock. From May – October, the outfall location is marked by three white buoys commonly referred to as “The Three Wise Men” by local fishermen and boaters.
Flow Rates
Average Day Flow: 10 MGD
Maximum Hydraulic Flow: 55 MGD
Collection System
The collection system includes two pump stations and is a separated sanitary sewer system, comprised of the following:
• 131,500 feet (24.9 miles) of sanitary sewer interceptor ranging in size from 12 inches to 84 inches in diameter.
• 361 manholes, one inverted siphon, 10 river crossings, and numerous special structures.
• 9,610 feet of 36-inch diameter force main
Collection System Flow Metering
SHVUA member communities are billed for their flows based on flow meter data. For some communities, flows are directly metered at their connection to the interceptor system. For other communities, billable flows are calculated incrementally by subtracting flows from the upstream community and/or subtracting estimated inflow/infiltration (I/I) flows of the regional system. The interceptor I/I estimate is removed from the total billable community flows shared by each community. However, all flow from the collection system, including interceptor I/I, is still treated at the WWTP and is included in the total operating costs of the system. In this way, interceptor I/I is considered a shared cost to all communities. There are 11 flow meter locations in the collection system as shown in the Service Area figure below.
SHVUA has a meter maintenance and data review program that includes quarterly routine maintenance and as-needed corrective maintenance; data review on a weekly, monthly and annual basis; and annual verification of meter accuracy.
Trenton Arm Pump Station
The Trenton Arm PS (TAPS) is located at 27491 West Jefferson Ave. Gibraltar, Ml on the east side of Jefferson Ave. just south of Vreeland Road. The TAPS has four variable speed pumps each rated at 13.5 MGD. The Trenton Arm PS discharges south into the Trenton Arm Interceptor to the WWTP via a 36-inch diameter force main extending from the PS approximately 9,700 feet to a highpoint located on Jefferson Ave. at South Gibraltar Road where the force main ends and transitions into a 54-inch RCP recently lined with CIPP. The facility’s firm capacity is rated at 39 MGD with three pumps running.
Odette Pump Station
The Odette PS was is located at 28880 Huron River Dr. in Flat Rock and originally built as a part of Section II of the old Flat Rock – Huron – Sumpter Interceptor system and was called Pump Station No. 2. The station is located at the Northeast corner of Odette Road and Huron River Drive. The Odette PS utilizes a 12-inch diameter force main extending 4,700 feet east flowing to the WWTP via the Old Flat Rock – Huron – Sumpter Interceptor which is a 24-inch gravity sewer. Historical plans indicate the design capacity is 880 gallons per minute (GPM) at 34-feet TDH per pump or approximately 1.3 MGD firm capacity.