DNREC monitoring another Lewes WWTP malfunction and discharge of partially-treated effluent into Lewes-Rehoboth Canal

DOVER – Department of Natural Resources and Environmental Control staff were dispatched today to the Lewes wastewater treatment plant (WWTP) after Tidewater Utilities notified the Department that the facility was once again forced to bypass stages of its treatment and discharge partially-treated effluent into the Lewes-Rehoboth Canal late Wednesday evening. The bypass lasted two hours while Tidewater operators worked to find a solution for problems with new treatment membranes. By 11:45 p.m. Wednesday Tidewater was able to end the bypass and resume normal treatment of effluent at the wastewater treatment plant.DNREC Logo

DNREC today monitored the WWTP’s operations and Tidewater Utilities’ continued efforts to mitigate recent system malfunctions at the plant. The Lewes WWTP discharged partially-treated effluent from Dec. 18-28, 2019 after a system malfunction caused contamination of the plant’s treatment membranes that filter flow. New membranes were installed Dec. 28, enabling full treatment to resume at that time, but Tidewater reported today that pressure build-up behind the new membranes required a bypass to avoid compromising their use. Tidewater, in consult with the membrane manufacturer, has instituted new operational protocols to minimize pressure build-up moving forward, with no further bypass events expected by plant operators. Tidewater also informed DNREC earlier today that an additional set of refurbished membranes are ready to be put back into service later today to help alleviate strain on the new treatment unit.

DNREC Secretary Shawn M. Garvin confirmed Monday that an environmental violation had occurred when the Lewes WWTP bypassed normal treatment operations between Dec. 18-28 because of the plant’s system malfunction, and that DNREC is currently gathering pertinent information before determining appropriate action. Department staff will continue to monitor the situation at the plant daily as Tidewater Utilities works toward maintaining consistent treatment of effluent without further system malfunctions.

Although the plant is currently back online and has resumed normal treatment of effluent, DNREC also encourages the public who depend on the Lewes WWTP plant to handle their wastewater to continue practicing water conservation while corrective measures continue at the plant.

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DNREC raises public awareness of Lewes WTTP effluent bypass discharge, closes Delaware Bay shellfish harvest areas

DNREC LogoDOVER – The Department of Natural Resources and Environmental Control was notified Wednesday, Dec. 18 of equipment malfunctions at the Lewes wastewater treatment plant (WWTP) that the facility operator, Tidewater Utilities, 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, Dec. 19.

Treatment stage 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 effluent 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, Dec. 20 to observe bypass conditions at the Lewes WWTP and Tidewater Utilities’ 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.”

Media contact: Michael Globetti, DNREC Public Affairs, 302-739-9902

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