Construction to begin in October
Department of Natural Resources and Environmental Control Secretary Shawn M. Garvin today signed a Secretary's Order enabling the City of Rehoboth Beach to move forward with construction of an outfall that will discharge the city’s treated wastewater into the Atlantic Ocean, eliminating the largest remaining point source discharge into Delaware’s Inland Bays.
The ocean outfall was the remedy chosen by the City of Rehoboth for complying with a court order to stop discharging effluent from the city’s wastewater treatment plant into the Lewes-Rehoboth Canal by June 1, 2018. The outfall will enable Rehoboth to achieve compliance with federal Clean Water Act and state standards for its wastewater discharge. When operational, the outfall also will bring closure to a lengthy process during which the city has worked to achieve wastewater compliance – starting in 1998, when DNREC promulgated a Total Maximum Daily Load Regulation requiring elimination of all 13 point sources of nitrogen and phosphorus discharging to the Inland Bays.
Before issuing the permits to the City of Rehoboth, DNREC evaluated the wastewater project put forward by the city to ensure that the ocean outfall met all legal, scientific and technical standards for bringing the city into compliance with its wastewater discharge. The Department is issuing permits for the outfall based on the Secretary’s determination that the City of Rehoboth Beach satisfied all regulatory requirements with its applications.
Since taking office in mid-March, Secretary Garvin has listened to numerous stakeholders with often disparate opinions and perspectives on the ocean outfall option.
“These are very dedicated individuals who have spent a great deal of time studying the issues and participating in the public process,” he said. “I wanted to glean as much information as possible from them before I made a decision. I sincerely appreciate the time they spent in discussion with me and the insights they provided the Department.”
Stakeholders had expressed concern about the ocean outfall’s potential impacts to Hen and Chicken Shoals, an important habitat for numerous marine species. Information in the hearing record, however, demonstrates that the outfall's alignment completely avoids Hen and Chicken Shoals and that the effluent, treated to a very high level, will not appreciably impact the shoals. Work done for Rehoboth by the city’s consultants also demonstrated that water quality, natural resources and public health would be protected by the alignment of the outfall, and that constructing it would have minimal environmental impact. Permits approved in the Secretary’s Order will restrict all work on the outfall to the colder months when wildlife and marine animals, including piping plovers, ospreys, and migrating fish, turtles and mammals, will not be impacted. Likewise, work will only be done during the offseason to avoid disruption of recreational uses of Rehoboth’s Deauville Beach.
The approved pipeline alignment will begin at the existing Rehoboth Beach Wastewater Treatment Plant and follow 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.
The city is advertising bid documents in the next week. Mobilization of equipment will begin in October 2017 with an anticipated construction completion in April 2018.