Brief Project Description
Grantee: Louisa County Water Authority
The proposed design for expanding the Louisa County Regional WWTP from 0.4 million gallons per day (MGD) to 0.8 MGD and converting to a Biological Nutrient Removal (BNR) facility is constructing two (2) new anaerobic reactors, two (2) new anoxic reactors, and modifying the existing oxidation ditches to achieve biological nutrient removal. The proposed treatment process, which utilizes a 100% to 400% internal recycle from the aerated oxidation ditches to the proposed anoxic tanks, in conjunction with tertiary filtration will be capable of meeting the nutrient removal effluent limits under design conditions. A summary of major plant additions and/or improvements required for the expansion and installation of nutrient reduction technology (NRT) is provided below. The summary includes the general treatment unit upgrades required to handle the increase in capacity as well as the recommended upgrades for achieving BNR at the expanded facility.
Proposed 0.8 MGD upgrade components and their eligibility as NRT are as follows:
- New Influent Pumps to handle increased flow (ineligible)
- Aerated Grit Chamber (ineligible)
- Two (2) Anaerobic Tanks with mixing capabilities (eligible)
- Two (2) Anoxic Tanks with mixing capabilities and diffusers to allow for aeration if needed (partially eligible)
- New blowers will be added to serve the anoxic tank and aerated grit (ineligible).
- Modify Discs/Drives in existing Oxidation Ditches for better oxygen control/increased output for higher oxygen demands for the expanded plant (ineligible).
- New internal recycle pump station to pump aerated sludge from Oxidation Ditch #3 to the proposed anoxic tank (eligible)
- One (1) conventional 50-foot diameter Secondary Clarifier (Clarifier #3) (partially eligible)
- Sludge Dewatering Building including belt press, sludge pumps, polymer feed system and return activated sludge (RAS) pumping station (partially eligible)
- Two (2) Tertiary Filters (eligible)
- Additional UV bank (rated at 0.4 MGD) and effluent channel (ineligible)
- New Cascade Aerator (ineligible)