Wastewater Ocean Outfall

PDF icon Ocean Outfall Town Hall Presentation Sept. 16, 2017.pdfThe 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 

The Rehoboth Beach Force Main Project is moving forward and is poised to begin major construction operations. All pre-construction activities, surveys, related studies, equipment deliveries, and clearing and grubbing are underway. All key subcontractors have been retained to work on the project. Construction to install 12,000 ft. of pipe in the street for the force main work will start at Roosevelt Street, the main road to the Wastewater Treatment Plant, and proceed down State Road to Canal Street. This section of trenching work to install the force main pipe is expected to begin the end of October and take approximately a month. The next section of work will be from Canal Street to Rehoboth Avenue. At the intersection of Canal Street and Rehoboth Avenue the contractor, A-Del Construction, will switch from open trench to jack-and-bore. A-Del will dig a pit and then drill a hole underneath Rehoboth Avenue and Grove Park and install a casing. A second pit will be dug outside Grove Park, and the pipe will be threaded through the casing to the second pit. Canal Street will be closed at Rehoboth Avenue during this time. Access to Canal Street will be from State Road. Once past Grove Park, the contractor will go back to an open trench cut down Henlopen Avenue to the Deauville Beach parking lot.

The force main pipe trench will be 5 to 6 feet wide and 4 to 20 feet deep. A-Del will be limited to only working in the road approximately 200 ft. at any time and traffic control will extend an additional 200 ft. on either side. The contractor will install approximately 50 to 80 ft. of pipe per day. The open trench areas will be covered with steel plates at night. All impacted roads will be repaved and the shoulder area along both sides of Henlopen Avenue will be restored with new gravel at the end of the project. All traffic will be maintained around construction zones, and the contractor is required to maintain access, water, electric, and sewer service to all properties during construction. The contractor will utilize maintenance of traffic standards established by DelDOT. Working hours are Monday through Friday from 7:30 am to 6 pm. 

The Deauville Beach parking lot is the main staging area for the 6,000 ft. of outfall pipe installation. The contractor, Manson Construction, is expecting to start receiving pipe on October 23 with fusing beginning on October 26. The pipe fusing will be staged near the DNREC Lewes Field Office inside the Roosevelt Inlet. Dredging is expected to begin late October. Manson anticipates the use of a total of six vessels and four barges for the project. The horizontal directional drilling contractor’s mobilization is underway and equipment is expected to arrive by the end of the month. Fencing is now in place around the perimeter of the parking lot and access is restricted to construction workers only. A pedestrian path to the tennis courts is located on the west side of the fence. 

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 PDF icon Agreement for Wastewater & Biosolids Services with Sussex County. Sussex County Council unanimously approved the 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.

Construction work at the Wastewater Treatment Plant on the first bid package (T-1 Immediate Needs 1) will be wrapping up this fall. The work included demolishing remains of the existing steel roof on T-1, installing a new precast concrete roof deck, with concrete beams and columns for support, mobilizing a temporary roofing system while a new plank is fabricated, installing a new roofing membrane and skylights. 

New skylight at the WWTP

We are in the shop drawing submittal phase of T-1 Immediate Needs II. As soon as things get final approval, they will begin to work on this portion. The work includes installing new lighting and electrical conduit on the upper level, installing new HVAC (fans and unit heaters) on the upper level, installing new exterior fiberglass doors and frames on the upper level and installing a new roof access ladder. 

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

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

Funding

Resources

 

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