MOUNT VERNON — The upgrade of the sewage treatment facility at Howard is about ready to go out for bids. The firm designing the project, ADR and Associates of Newark, met with the Knox County Commissioners Monday afternoon to answer some final questions from the commissioners before the project proceeds.
The main issue discussed was the difference between a “vertical loop reactor” (VLR) and a “sequencing batch reactor” (SBR).
According to Project Manager Jeffrey Carr of ADR, the VLR is a flow-based system and the SBR is a batch-based system. If the VLR system receives a large amount of water above the normal amount of sewage, the sewage will not receive as much treatment before discharge. The SBR system uses multiple containers to treat each batch of sewage for a specified amount of time. Carr noted that in the case of an inflow of water, such as might happen in a storm, the plant’s discharge might violate environmental standards.