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Like the Energizer Bunny, discussion of Rehoboth Beach’s wastewater disposal alternatives keeps going and going. But at the Monday, July 21 city commissioners’ meeting, the discussion gave a new glimpse into one of its possible two futures.
Dr. William Ullman of the University of Delaware’s College of Marine and Earth Studies advocated ocean outfall as the best alternative for the city.
Ullman said ocean outfall should be preferred because it gets nutrients out of the watershed.
“We’re bringing lots of nutrients from the outside and we’re not exporting them as fast as we’re bringing them in,” Ullman said. He said anything that can be done to export nutrients out of the watershed would benefit the Inland Bays. He said the outfall decision was an opportunity to take nutrients and pump them offshore now instead of waiting 50 or more years for the nutrients to be removed by natural processes.
“Anything you put out on the land now, 50 years or so, maybe even longer, will get out to the ocean and be discharged anyway,” Ullman said. “Why not just short circuit that.”
He said the major issue with discharging to the canal and northern Rehoboth Bay was both were poorly flushed systems isolated from the ocean. The waters off Rehoboth are well flushed by waters from the Delaware Bay.
“You want to improve flushing. You do that by going to some place that you can dilute this material fairly well and rinse it out fairly well,” Ullman said.
He said Delaware Bay has both tidal saltwater and fresh water, from the Delaware River, going in and out every day. He said the total tidal saltwater alone discharges 250,000,000 times more water than Rehoboth’s wastewater treatment plant sends out. Ullman said the water from ocean outfall would be insignificant compared to the high volume of water flushing in and out of Delaware Bay.
“I would say this is a drop in the bucket. It isn’t, it’s a thousandth of a drop in the bucket. It’s a very small number,” he said.
Ullman also pointed to the decreases in phosphorus and nitrogen loads since 2002 as a result of Rehoboth’s upgrades to its wastewater treatment plant. The city has decreased its phosphorus load from 2,250 kilograms a year prior to 2002 to 750 kilograms a year. Nitrogen loads have been cut in half, from 15,000 kilograms a year to 8,000 kilograms a year.
Ullman also cited South Bethany’s ocean outfall, which has existed for more than 40 years and has very few complaints. That outfall is much bigger than the one proposed in Rehoboth and is regulated by the Environmental Protection Agency, he said.
Besides Ullman, there were environmental officials from Sussex County and the Department of Natural Resources and Environmental Control (DNREC), in addition to Rehoboth Wastewater Treatment Plant Manager Bob Stenger and Rip Copithorn of Sterns and Wheler, the engineering firm that produced the city’s wastewater report in 2005.
Sussex County engineer Mike Izzo said the city should consider ocean outfall if the economics justify it, but one was not better than the other. He said spray irrigation, which the city could join with the county for a regional solution, was not a farming operation but a wastewater disposal operation.
“We’re spraying where we need to spray. The yields are not real good. If you are out there farming right now and you think having a wastewater/spray irrigation operation is going to increase your yield, you are incorrect,” Izzo said.
The Rehoboth commissioners will discuss the wastewater topic at every meeting from here on out. Commissioner Stan Mills suggested holding a special Saturday meeting in late September with all the major players: the county, DNREC, Sterns and Wheler, and Stenger, among others. The city has until December 2014 to stop dumping its wastewater in the Lewes-Rehoboth Canal
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