Wastewater Ocean Outfall

The City of Rehoboth Beach is required, under the terms of a consent order from the Dept. of Natural Resources, to eliminate the discharge of treated effluent from the Rehoboth Beach Wastewater Treatment Plant into the Lewes-Rehoboth Canal. The city, after detailed studies and the evaluation of all options, is proposing an ocean outfall in order to comply with that order.

Wastewater Outfall pathThis project consists of a new pump station and a 24-inch force main/pipe which are required to convey the treated effluent to the ocean outfall and to provide the head required to pump the effluent through diffusers located 6,000 feet offshore in water approximately 40 feet deep. Vertical turbine effluent pumps will be installed in the existing post-aeration tank. The force main will be aligned along the plant access road and end at the public access parking area at the beach near Henlopen Avenue.

The pipeline from the Rehoboth Beach Wastewater Treatment Plant to the ocean outfall was sized to handle the summer peak flow. As part of the overall project analysis, a detailed alignment study was completed to determine the best routing of the force main considering such issues as cost, environmental issues, permitting, potential interferences, traffic control, and public concerns. The preferred alignment was selected based on the recommendations of the Rehoboth Beach Wastewater Treatment Plant Effluent Force Main Alignment Study.

Project Update 

Drone video of the ocean outfall HDD Pipe towed from Lewes to Rehoboth. 

Please visit our YouTube channel for more videos at https://www.youtube.com/c/rehobothbeach


All sections of the force main have been constructed except for two small sections on each side of the jack and bore. These connections will be constructed upon completion of testing for the jack and bore pipe, which is the third and final section of pipe to be tested. The jack and bore pipe are currently being filled with water. Testing will be completed early this week. Canal Street from Sixth Street to Rehoboth Avenue remains closed. Access to Canal Street is for local homeowners only.

The contractor is patch paving on Henlopen Avenue this week at the intersections of Third Street, Gerar Street, Easton Street and Felton Street. The crew is anticipated to move to Henlopen Avenue for restoration and paving after Memorial Day. Milling and the road base coat work is scheduled to begin May 29th. The contractor will start on the north side of Henlopen Avenue at Grove Street working towards Surf Avenue then the south side. The stone shoulder will be installed next on both sides of the road followed by the top coat of paving. Barrels and signage with no parking dates and times will be posted the day before work is scheduled for a specific area. Please do not park in the posted areas. The contractor working hours on Henlopen Avenue will be 6:30 a.m. to 6:30 p.m. and Canal Street 8 a.m. to 5 p.m.

Traffic impacts will be minimized as much as possible, however, during work adjacent to your property there will be 3-4 hours where you cannot access your driveway. Provisions will be made to ensure that the contractor allows refuse pickup, mail and delivery service to be maintained during the project. This phase of work is scheduled for two weeks. All work is weather dependent.

If you would like to install different stone after the restoration is complete, please contact the Building & Licensing Department at 302-227-6181 ext. 222 or [email protected] with your intended plans. 

The focus of this project has always been the importance of the consent decree, first and foremost, to comply with the federal and state mandates of June 1, 2018, to have an operating ocean outfall. Although May 23, 2018, was anticipated as a project completion date, most paving and restoration work will extend beyond that date. The Commissioners approved a change order May 1, 2018, to authorize a modification to the paving on Henlopen Avenue at an additional cost of $310,000. Presently, Henlopen Avenue has very little supporting material under the existing pavement other than sand. The approved change order for the entire street entails a layer of 3 ½ inches of support fill material and then a layer of 2 inches of top paving. This is a very important change order for creating a much stronger foundation for Henlopen Avenue. This will allow for a way of arresting the deterioration and extending the street’s life. 

The agreement with the contractor, A-Del, specifies May 14 for substantial completion of the force main work. This date was extended to May 31 due to underground utility line issues not readily identified. This is on target at this time. The agreement further specifies the date of July 12 for final completion but was extended to July 29, which includes the paving and restoration of the roadways. Please contact the Communications Department at [email protected] or 302-227-6181 ext. 522 with your questions and concerns. Thank you for understanding the importance and extent of this project.

PDF icon Force Main Lookahead Schedule


All offshore work has been completed. Manson has completed final surveys and demobilized. The sub-contractor is completing the restoration of the dune and parking lot. The Deauville Beach parking lot continues to be closed to the public. Access to the tennis courts is from Surf Avenue. The parking lot is anticipated to open by Memorial Day weekend.   

The U.S. Army Corps of Engineers permit had a condition of approval, which limits in-water work from April 1 through September 30 in any year. The actual permit deadline for completion of all work is December 31, 2020. The weather has been a considerable challenge during this project and continues to affect offshore work. It is anticipated the contractor will be able to complete a majority of the in-water work prior to April 1, 2018. However, there will be some in-water work days that will occur on or after April 1, 2018. The U.S. Army Corps of Engineers has modified the permit to allow for in-water work to be performed on or after April 1, 2018.

A permit modification has also been approved by the Department of Natural Resources & Environmental Control – Division of Water for the Subaqueous Lands Permit. The permit had a Time of Year Restriction (TOYR), allowing the contractor to work from October 15 through March 31, 2018. The permit modification has amended the TOYR for in-water work to be performed between October 15 through May 23, 2018.  This modification requires additional conditions including a marine mammal observer to be present for all in-water work performed beyond the March 31 deadline. In addition to a marine mammal observer, the contractor shall perform turbidity and seawater temperature monitoring and reporting daily. 

 PDF icon Ocean Outfall Three Week Lookahead Schedule


  • Construction completion:  Ocean Outfall May 2018 – Force Main May 2018


Doors, windows and concrete supports are being installed in Filter Building B-2. The contractor has installed the spray water piping in Clarifier T-3A. The pump manufacturer has completed dry testing of the pumps and approved installation in Effluent Pumping Station PS-3. The contractor is in the process of hydrostatic testing the below-grade piping. The GHD programmer has installed the control programs for the equipment. 

Please contact the Communications Department at 302-227-6181 ext. 522 or [email protected] for additional project information or questions. 

New skylight at the WWTP

On August 14, 2017, the Rehoboth Beach Commissioners unanimously approved awarding four bid packages to various contractors to begin construction on the ocean outfall project. The project consists of a new pump station and 24-inch force main, which are required to convey the treated effluent to the ocean outfall and to provide the head required to pump the effluent through diffusers located 6,000 feet offshore in water approximately 40 feet deep. The bids totaled $37,381,407. The ocean outfall bid was awarded to Manson Construction of Seattle, Washington, for $27,655,850. Allan Myers Construction of Worcester, Pennsylvania, was awarded the effluent pumping station bid for $1,768,555, and the wastewater treatment plant upgrades for $2,256,555. A-Del Construction of Newark, Delaware, won the force main bid for $5,700,447. Contractors were pre-qualified by GHD, the engineering company for the project. Steps taken to pre-qualify were assessing each contractor's project completion record, reviewing their performance on similar projects, safety record, insurance coverage and other factors. Mobilization of equipment will tentatively begin October 1, 2017, and work is to be completed by April 30, 2018.

On August 7, 2017, the Rehoboth Beach Commissioners unanimously approved a renewed and expanded Agreement for Wastewater & Biosolids Services with Sussex County. Sussex County Council unanimously approved the PDF icon Agreement for Wastewater & Biosolids Services at their meeting on August 8, 2017. Under the new agreement, the county will continue to pay the city to treat wastewater from surrounding areas of the county's sewer system. The county will be responsible for hauling via truck the city's biosolids to a new treatment plant at the county's Inland Bays facility. Fees will be determined once the new facility is operational, and the city will not have to contribute to operating costs until that time. Sussex County's contribution toward the $52.5 million outfall project will be based on utilization of services.

Announcement of Rehoboth Beach issuance of outfall permitting

On May 25, 2017, Delaware Department of Natural Resources and Environmental Control (DNREC) Secretary Shawn M. Garvin approved and signed the Secretary’s Order for the Rehoboth Beach ocean outfall which includes all required DNREC permits to move forward with construction. The U.S. Army Corps of Engineers will be issuing a permit along with a Sediment and Stormwater Permit from the Sussex Conservation District, and DelDOT permits for work on state road right-of-ways.

The approved pipeline alignment begins at the existing Rehoboth Beach Wastewater Treatment Plant, follows the Lewes and Rehoboth Canal north to Grove Park. The pipeline will then turn northeast to Henlopen Avenue and continue along Henlopen Avenue to the Deauville Beach parking area and terminate in the Atlantic Ocean, approximately 6,000 feet from the parking area. The 24-inch high-density polyethylene (HDPE) pipeline will be installed via horizontal direction drill approximately 3,000 feet and marine open-cut trench approximately 3,000 feet. Once the pipe is anchored in place with concrete collars, the open-cut trench will be backfilled. The terminus of the outfall pipe will consist of a 120 linear foot diffuser comprised of eight risers, 1.5 feet above the ocean floor, with four discharge ports per riser. The diffuser will be installed on pilings to ensure stability. Mobilization of equipment will tentatively begin October 1, 2017, and work is to be completed by April 30, 2018.

The Secretary's Order can be viewed at http://www.dnrec.delaware.gov/Info/Pages/SecOrders_Permits.aspx

Change Orders

Approved Permits

Bid Information

Contract Information

DNREC Workshop & Hearing

DNREC Public Workshop October 19, 2016
DNREC Public Hearing November 15, 2016

Frequently Asked Questions

FAQs regarding the Wastewater-Implementation of Ocean Outfall Alternative Discharge




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