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Poplin Road Pump Station Force Main Discharge Location - Alternatives Analysis
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INFORMATION CONTACT:
John Shutak, Union County Water, Engineering Director, 704-283-3651
ACTION REQUESTED:
Receive direction from the Board of County Commissioners on odor mitigation strategies for the Poplin Road Pump Station force main discharge location in the Heritage Subdivision.
PRIOR BOARD ACTIONS:
February 5, 2024, Regular Meeting, Agenda Item # 24-081 - Received information regarding options for mitigating odors from the Poplin Road Pump Station force main discharge location in the Heritage Subdivision.
BACKGROUND:
The Poplin Road Pump Station is located adjacent to the Annandale Subdivision along the North Fork of Crooked Creek and pumps wastewater from the Crooked Creek service area to the Twelve Mile Creek WRF collection system. Wastewater is conveyed through approximately 7 miles of piping and discharges to a manhole in the Heritage Subdivision on Curling Creek Drive. Union County has received complaints regarding odor in this area, and staff were directed to evaluate alternatives to address the noted issues.
UCW engaged Black & Veatch to assist staff with the collection of field data and the development of alternatives and costs for mitigation. The alternatives identified from this study included vapor phase treatment, relocation of the force main discharge, modifications to the receiving gravity sewer manhole, odor control scrubber with sealed manholes, and liquid phase treatment. The analysis included a breakdown of capital costs and operating costs for each treatment option.
The recommended solution was presented to the Board of County Commissioners (BOCC) on February 5, 2024. The recommended solution was a two-stage approach with the primary treatment being liquid phase treatment upstream of the force main discharge location, and the secondary treatment being vapor phase treatment at the discharge manhole in the Heritage Subdivision. The secondary treatment of installing manhole odor scrubber inserts at the discharge manhole was implemented following the February 5, 2024 update to the BOCC because this could be done at a minimal capital and operating cost with the current system operating budget. A pilot study for the primary liquid phase treatment could be implemented for a 50-day trial period for approximately $70,000.00. If the pilot study proved to be effective at mitigating the odor issue, then a permanent liquid phase treatment system could be installed with an estimated annual operating expense of approximately $250,000.00. Staff is requesting direction from the BOCC on whether to initiate a pilot program for the liquid phase treatment system.
FINANCIAL IMPACT:
None. This request for direction will only direct staff on whether to start the process of procuring services for a pilot study for liquid phase treatment. Board approval of the pilot program contract will be requested at a later date.