On the morning of July 5, Anacostia Riverkeeper Trey Sherard went out to the dock at Kingman Island to carefully collect and label water samples for testing. The water quality results from that day would determine, in part, whether the Department of Energy and Environment would grant a permit for Anacostia River Splash, a historic swim event scheduled for Saturday, July 8.
“They give us numbers back tomorrow,” Sherard said that morning, describing the 24-hour process for testing the water. “Then we hope it doesn’t rain hard between now and [the event].”
Just a few hours after that conversation, thunderstorms rolled in. The weather over the following three days saw short bursts of heavy rainfall across the D.C. area. On the afternoon before the event date, DOEE and Anacostia Riverkeeper announced that the swim event would be postponed to September.
Because parts of the District have a combined sewer system — where rainwater runoff, sewage, and industrial wastewater all collect into one pipe — heavy rain sometimes overwhelms the system. Those instances, called combined sewage overflows or CSOs, can send untreated sewage straight into D.C.’s waterways.
This week’s rain caused two relatively small CSOs, one near Navy Yard and one by RFK Stadium, said John Lisle, DC Water’s vice president of marketing and communications.
“Any event that you’re doing on the river is dependent on the weather and how much rain you get, and whether you get CSOs,” Lisle said. “That’s kind of built in.”
The problem used to be far worse, with billions of gallons of sewage running into D.C.’s rivers. But a massive court-ordered project that began in the early 2000s has opened up huge tunnels designed to hold excess water, which has caused massive improvements in water quality. Since coming online in 2018, DC Water explained the Anacostia River Tunnel has reduced sewage overflows into the river by 90%.
A second phase of the project is set to come online at the end of this summer, and DC Water expects it to bring the reduction to 98%.
Another Variable: Part of a Tunnel Near RFK Was Offline This Week
Because of construction on the new Northeast Boundary Tunnel, DC Water had to take part of the existing tunnel offline for about a month, Lisle said.
At that disconnected section, located by RFK Stadium, about 2 million gallons of sewage went into the river on Thursday. The spot is less than two miles from the site on Kingman Island where the swim event would have taken place (though the planned swim site is upstream).
Anacostia Riverkeeper said its team had not known that part of the tunnel infrastructure would be disconnected during the event.
“We did not know that the CSO controls were expected to be offline at this exact time,” McKenzie Ingram, the organization’s outreach and volunteer coordinator, said in an email. “If we had known ahead of time, we would have not scheduled Splash while the tunnels were offline.”
Jeffrey Seltzer, deputy director of the Natural Resources Administration at DOEE, said in an email that the agency — which worked closely with Anacostia Riverkeeper on the event — had known that DC Water would need to take parts of the system offline for construction during the summer. But, Seltzer said, they did not know the specific dates until June 30, less than a week before an event that had been months in the making.
“Even with the tunnel off-line, there are many days when water quality will support swimming,” Seltzer said. “It’s unfortunate that the timing didn’t work for this weekend, but we are excited to see the event rescheduled for later this fall.”
Lots of Improvement — But Still More Work To Do
Even once the entire tunnel system is online and complete, extreme rainfall may still occasionally cause overflows. Thursday’s CSO at Navy Yard, Lisle said, happened because the heavy rain simply fell too fast to be collected into tunnels—not because there was any issue with the capacity.
Separately, rainfall also washes polluted runoff from the city into the Anacostia.
“That comes in not from a discrete set of sources like combined sewer overflows — it’s coming in from the entire watershed, everywhere,” Sherard said. “Somebody doesn’t pick up their dog poop: it does vanish from the yard when it rains, because it vanishes to here [in the river].”
Still, several places along the Anacostia have water quality good enough for swimming 80% or 90% of the time, according to testing conducted by Anacostia Riverkeeper.
Seltzer said that the results from Wednesday’s water sample — which Sherard took before the past few days of rain and the two CSOs — were “well within the standards for swimming safely.” But without time to do new tests, DOEE decided to postpone the event.
The new date for Splash will likely be set for sometime after the new Northeast Boundary Tunnel goes online, completing the Clean Rivers Project’s work on the Anacostia River and even further improving the water quality.