A D.C. conservation group is developing an app to track the Anacostia River’s water quality — for future swimmers.
The nonprofit Anacostia Riverkeepers is uploading data about the river’s water quality to an app that users can check to see if bacterial levels are too high for human contact.
The Ontario-based SwimGuide app makes the information available to anyone, but some experts say the data need more context for someone to make an informed decision to swim in the once-toxic body of water and for officials to warn people not to swim there.
The Riverkeepers now takes weekly samples at eight locations in Southeast and Southwest along the riverbank and tests each sample for bacteria.
“If a site’s sample on a given day fails to meet the standard, it will be shown in red,” said Trey Sherard, a biologist with the Riverkeepers. “The app uses bright green and bright red for ‘current’ samples, taken within the previous week. After a week’s time, the sites show a muted green, yellow, or red, based on that site’s historical pass/fail average.”
Historically, the Anacostia has been one of the most polluted waterways in the country, with billions of gallons of raw sewage, industrial waste and other debris flowing into it each year. Harmful bacteria typically registered 500 times higher than safe levels. In recent decades, public and private entities have worked to clean up the river and preserve the Anacostia watershed.
Regional authorities have dubbed 2018 the “Year of the Anacostia” to celebrate the clean-up efforts. Though officials say the river is cleaner than it has been in decades, they still ban swimming and restrict fishing in its waters.
“Despite the ban, we know people are going to use the river, so we want to have the most current and accessible data possible,” Jeffrey Seltzer, associate director of the Water Quality Division of the D.C. Department of Energy and Environment, said of the Riverkeepers’ SwimGuide app.
The department last month awarded the group a $150,000 grant to test bacteria levels.
SwimGuide launched in 2011 and has monitoring data for 7,000 beaches in six countries that are submitted by conservation groups like the Riverkeepers, said Gabrielle Parent-Doliner, the company’s program manager.
As of last week, the Anacostia’s data is available on the free app. All sample sites, except for Yards Park, tested “in the green” for bacterial level.
This year D.C. Water activated the first of several new sewage tunnels and began construction on a second one last week. The District aims to reduce raw sewage input into the river by 98 percent as part of the Clean Water Act for 2025.
But experts say the river’s swimmability remains more complicated than some app users might think.
“It needs more context around it. It shouldn’t be just a data point,” said Anacostia Watershed Society President Jim Foster.
Mr. Foster said he supports the Riverkeepers’ work, but warned about app users extrapolating too much information from a small collection of samples.
For instance, he said he would like the app to include data on how fast the river can move bacteria or debris — crucial information when deciding how soon swimmers can return to water after a storm.
“There’s very little baseflow in the [Anacostia] river because we’re tidal,” Mr. Foster said. “So the river kind of ends up sloshing back and forth like a bathtub.”
The app also doesn’t include information about legacy pollution leftover from the river’s industrial sites. Mr. Foster and Mr. Sherard said the pollutants are mainly concentrated in sediments at the bottom of the river and humans aren’t likely to encounter them, but scientists are learning about how the toxins affect fish and other wildlife.
“It’s far from the whole story,” Mr. Seltzer said of the app’s limitations. “I don’t want to anyone to get the impression that when they see a green light on this, it’s all OK.”
Nonetheless, the Riverkeepers hopes that weekly data can help in the first step to overturning the city’s swimming ban.
“DOEE is pending final confirmation of a rule change to allow swimming by special permit for events in the Anacostia, similar to the Potomac (like the Nation’s Triathlon) so that step is already underway,” Mr. Sherard wrote in an email.