DOVER, DE – The Department of Natural Resources and Environmental Control was notified Wednesday, December 18, 2019 of equipment malfunctions at the Lewes wastewater treatment plant (WWTP) that the facility operator, Tidewater Inc., was working to correct. Due to the nature of the affected equipment, the malfunction could not be expeditiously resolved, which required the Lewes WWTP to begin bypassing stages of its treatment, and begin discharging partially-treated wastewater effluent from the facility the evening of Thursday, December 19, 2020.
Treatment bypass is ongoing as Tidewater, Inc. works to implement interim corrective measures at the facility, until the malfunctioning equipment can be replaced or repaired. Lewes residents are encouraged to reduce water usage if possible in an effort to alleviate any unnecessary strain on the wastewater treatment system. Water conservation measures would include avoiding multiple partial loads of laundry or dish washing, reducing shower time, and minimizing unnecessary flushing of toilets.
Also as a result of the Lewes WWTP’s bypass situation, DNREC Secretary Shawn M. Garvin has issued an emergency shellfish closure order for harvest areas downstream of the plant. Discharge from the WWTP flows into the Lewes-Rehoboth Canal which predominantly flows to the Delaware Bay. The shellfish harvest closure affects the lower Delaware Bay, from the Mispillion River Inlet south to The Point at Cape Henlopen State Park, and Delaware jurisdictional waters east to the New Jersey State line in the Delaware Bay.
DNREC’s Surface Water Discharges Section was onsite Friday, December 20, 2019 to observe bypass conditions at the Lewes WWTP and Tidewater’s efforts to remedy the system malfunction. Effluent continues to be screened to remove visible solids prior to discharge, while a hydrogen peroxide feed is being utilized for bacteria reduction. DNREC has ordered the Lewes WWTP to perform enhanced monitoring of effluent, as well as upstream and downstream monitoring of discharge in the Lewes-Rehoboth Canal. In an abundance of caution while the bypass continues, DNREC advises area residents and recreationalists not to use the Lewes-Rehoboth Canal from one mile southeast of the Lewes WWTP out through the Roosevelt Inlet.
The closure of shellfish harvest areas because of risk to public health will continue for a 21-day period after the bypass situation has ended, and the Lewes wastewater treatment plant effluent meets required discharge standards. The closure ordered by DNREC is based on US Food and Drug Administration (FDA) Guidelines under the National Shellfish Sanitation Program, and provides adequate public health protection for pathogens of concern, including viruses.
Rehoboth Bay was determined not to have been impacted by Lewes wastewater discharge after previous studies by DNREC concluded that the net flow of effluent from the Lewes WWTP plant enters Delaware Bay, but not the state’s Inland Bays. The temporary closure announced by DNREC applies only to clams, oysters and mussels – crabs, conch and fish species are not affected.
In assessing the ongoing bypass situation, DNREC’s Delaware Shellfish Program said that “based on location of the event, commercial oyster beds will not be impacted,” and that the impact “will primarily affect recreational shellfish harvesters near the Cape Henlopen Fishing Pier, and a very limited commercial harvest of dredge clams in an area where no landings of these clams have occurred for several years.”
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