A malfunction at the Lewes wastewater treatment that started Dec. 18 is expected to be repaired by the weekend.

UPDATE, Dec. 25: The Department of Natural Resources and Environmental Control has released more information regarding the wastewater treatment facility malfunction in Lewes.

The malfunction occurred when the wastewater treatment system's membranes, which are similar to filters, were contaminated during an automated backwashing process. According to multiple wastewater treatment system distributors, the backwashing process is typically used to clean the systems.

The membranes must be replaced and other equipment repaired before the system can return to full treatment. Tidewater Utilities, Inc., the operators of the facility, expects the new membranes to arrive at the plant by Dec. 27 for immediate installation.

Until then, multiple locations, from the Lewes-Rehoboth Canal to the Delaware Bay, will continue to be sampled for fecal bacteria counts.

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Dec. 23: Partially-treated wastewater is flowing into the Lewes-Rehoboth Canal after a failure at the Lewes wastewater treatment plant, prompting an emergency local shellfish harvesting ban.

The Department of Natural Resources and Environmental Control was notified of “equipment malfunctions” at Tidewater Inc. Wednesday, Dec. 18, and the Surface Water Discharges Section observed conditions there Friday, Dec. 20.

A public statement was issued just after 5 p.m. on Monday, Dec. 23.

“Due to the nature of the affected equipment, the malfunction could not be expeditiously resolved, which required the Lewes [plant] to begin bypassing stages of its treatment, and began discharging partially-treated wastewater effluent from the facility the evening of Thursday, Dec. 19,” the statement reads.

The exact nature of the malfunction was not identified, but the wastewater is being screened to remove visible solids and hydrogen peroxide is being used to reduce bacteria. Requests for comment from DNREC, the city and Tidewater Inc. were not immediately answered.

The effluent is flowing and will continue to flow into the canal until the malfunctioning equipment can be replaced or repaired. According to DNREC, Tidewater is working to take what correctional measures they can in the interim.

The department is asking Lewes residents to reduce water use, if possible. Water conservation measures such as avoiding multiple partial loads of laundry or dish washing, reducing shower time and minimizing unnecessary flushing of toilets are encouraged.

Residents are also advised to refrain from recreating in the Lewes-Rehoboth Canal, from one mile southeast of the Lewes plant north. Previous DNREC studies found that the “net flow” of treated wastewater from Lewes enters the Delaware Bay, but not Delaware’s inland bays.