Guest Column: New Rehoboth Beach outfall means healthier inland bays


On Friday, June 15, officials and members of the community gathered to cut the ribbon and celebrate the completion of the City of Rehoboth Beach’s ocean outfall project. A win for the Inland Bays, this outfall will prevent over 17,000 pounds of nitrogen and 1,000 pounds of phosphorus from entering the Bays each year!

“The completion of this very important project for the City of Rehoboth Beach marks a time in history when future leaders and our informed citizens will reflect on how clean water in the Inland Bays plays such a vital role in their daily lives,” explains City Manager Sharon Lynn. “I am thankful to all who contributed to the ocean outfall project completion as I can’t think of too many other projects of this magnitude that will be advanced for a more important purpose.”

For decades, wastewater from Rehoboth Beach has degraded Delaware’s Inland Bays, an ecologically sensitive area designated as an “estuary of national significance” by United States Congress. Although the wastewater was treated prior to draining in the Lewes and Rehoboth Canal, nitrogen and phosphorus remained in the water. These nutrients are harmless to humans, but the slowly flushed Inland Bays are extremely sensitive to even small amounts of nutrient pollution.

When concentrated in a small estuary like the Inland Bays and their tributaries, nutrient pollution feeds algae and causes large algal blooms. This slimy excess algae then uses up the dissolved oxygen in the water, leaving too little for fish, shellfish, and other marine species to survive. Examples of this phenomenon are often seen during the summer months in Love Creek, Whites Creek, Shell Landing Cove, off of Rehoboth Bay, and the canals of South Bethany. Once pollutants get in the Bays, they remain there for a long time.

Removing this discharge instantly stops an astonishing 17,000 pounds of nitrogen from being pumped directly into the Rehoboth Bay every year — that’s the equivalent of preventing the use of 3,400 50-pound bags of fertilizer (another source of excess nutrients) from being used on land within the watershed. It will also stop the contribution of over 1,000 pounds of phosphorus each year — removing the equivalent of 2,200 50-pound bags of fertilizer and an amount equal to over 30 percent of the annual phosphorus load to Rehoboth Bay.

The removal of the discharge will have immediate and significant positive benefits to the water and all the people and creatures that rely on it. This was the final significant point source of wastewater to the Inland Bays to be addressed from an original 13 point sources. The Allen Harim facility near Millsboro has plans to remove the very last pipe, which discharges a small amount of wastewater to Wharton’s Branch on Indian River.

Now, Rehoboth’s treated wastewater discharge is being sent one mile out into the ocean where it is quickly diluted. Studies contracted by the city of Rehoboth Beach have demonstrated that the discharge will be diluted 100:1 within a few hundred feet of the outfall in under 6 minutes. As such, there will be little impact to aquatic life there as a result of the new outfall. Another ocean outfall off Bethany Beach has operated successfully for decades.

This decision of whether to implement an ocean outfall or to go with a land-based disposal alternative was explored by the City and the State. The outfall was eventually selected as little affordable land was available for the proposed disposal, and land-based disposal would only continue to feed nutrients back into already-polluted estuaries through groundwater.

This project has addressed a major problem facing the City of Rehoboth, and our Inland Bays. By dispersing the City’s wastewater into the well-flushed, wide expanse of the Atlantic, the outfall has created real change for the Inland Bays. We look forward to seeing the progress in the coming weeks, months, and years.

Amy Barra is the outreach and education coordinator for the Delaware Center for the Inland Bays. For more information, call Barra at (302) 226-8105, ext. 103, send an email to abarra@inlandbays.org or visit www.inlandbays.org.

By Amy Barra
Delaware Center for the Inland Bays