Lewes wastewater treatment plant back online after malfunction

LEWES — The Lewes wastewater treatment plant is back online and has resumed normal treatment following a malfunction from earlier this month, authorities said.

The Dec. 18 malfunction was caused by an automated backwashing process. Tidewater Utilities informed the Department of Natural Resources and Environmental Control that treatment membranes contaminated during the backwashing process had been replaced, ending the plant’s system bypass operation that discharged partially treated effluent for nine days into the Lewes-Rehoboth Canal and the lower Delaware Bay.

Tidewater Utilities installed new treatment membranes Monday to treat incoming flow as normal and discontinue bypass pumping.

DNREC staff was onsite at the plant directing Tidewater Utilities’ sampling of the partially treated effluent for bacteria levels and monitoring the sampling for possible health risks.

When the system malfunctioned and the bypass operation began, DNREC also ordered immediate closure of shellfish harvest areas in the lower Delaware Bay due to health concerns from partially treated effluent, a written statement said.

The closure of shellfish harvest areas will continue for a 21-day period from the time the bypass situation ended and Lewes wastewater treatment plant’s effluent met required discharge standards. The closure ordered by DNREC is based on US Food and Drug Administration (FDA) Guidelines under the National Shellfish Sanitation Program.

The closure applies only to clams, oysters and mussels – crabs, conch and fish species are not affected.