One day in late January, I went for a hike in Rock Creek Park. I emerged alarmed by what I had learned there about E. coli levels in the creek, and by the dearth of public warnings about its health hazards.
While hiking on Black Horse Trail. I saw two water technicians from the U.S. Geological Survey (USGS) taking samples from Rock Creek at the Joyce Road bridge. USGS regularly samples and analyzes the temperature, turbidity (sediment), and organic and inorganic chemicals and elements at this location. I asked one of the techs, David Brower, how the water looked.
“I can’t make qualitative statements about the water,” he replied. I thought a bit, then asked, “What is the level of E. coli in the water?”
“It is very, very high,” he said.
Brower went on to explain that the water has to be diluted by a factor of 1,000, or the readings would be off the charts. And he stressed that these E. coli levels pose a hazard to human and dog health. He told me that I should warn people not to come into contact with the water. Brower told me he often sees people and their dogs doing so, and it worries him.
I continued my walk, sobered by the conversation and wondering why there were no warning signs posted along the water where I often see adults, children and dogs playing around.
Back at home, I sought more data about E. coli levels from USGS, and answers about signage from the National Park Service and the DC Department of Energy and the Environment (DOEE).
USGS sent EPA links to reports it had conducted for DOEE in 2020. Then, too, it found high bacteria levels in Rock Creek as well as Soapstone, Broad Branch, Melvin Hazen and other Rock Creek tributaries. Its term for the water conditions is “impaired.”
As for warning signage, Rock Creek NPS first forwarded my question to Rock Creek Conservancy, which sent me an example of a sign the organization has placed in some locations:
“Stay safe while enjoying Rock Creek Park. Swimming and wading are not allowed due to high bacteria levels.”
Compare this to the warning signage posted by Montgomery County.
I sent the Maryland sign to Rock Creek NPS and DOEE. Rock Creek Park Superintendent Julia Washburn sent me a statement about the Park Service’s stream monitoring and restoration partnerships with Rock Creek Conservancy and DOEE. “We have used signs, social media, and web content to warn against wading, swimming, and pets in the streams. As we improve signage in the park, we will continue to make the public aware of unsanitary water quality,” the statement said.
And from DC’s environmental agency, I got this response: “DOEE is exploring options with our sister agencies to develop and install signage warning the public of this ongoing risk.”
DOEE has been monitoring E. coli levels in the District’s streams and rivers for some time. The agency conducts weekly testing with the aid of volunteers.
Because “[b]acteria levels in Rock Creek are frequently higher than water quality standards and pose a risk to the health of people and pets,” the District bans swimming and wading in Rock Creek and other DC waterways, DOEE said in its statement.
“However, many residents and visitors (as well as their pets) are unaware of this risk and do recreate in Rock Creek waters.”
Where is the E. coli coming from? DOEE’s Jeff Seltzer told me that the agency and partners are conducting several studies in an effort to identify the sources. Those include:
· In partnership with EPA and Virginia Tech, identifying human and non-human (i.e., dog, deer, and bird) sources of bacteria using new molecular techniques known as microbial source tracking in the Anacostia and Rock Creek watersheds. Results show that humans and wildlife are both substantial sources and bacteria pollution from these sources increased dramatically after rainfall.
· In partnership with USGS measuring stormwater runoff and bacteria near Luzon Branch in Rock Creek.
· In another partnership with Virginia Tech conducting studies of human bacteria pollution in the Anacostia River and its tributaries using different molecular techniques to those previously mentioned.
· In another USGS study using in-situ methods to directly measure bacteria in the Anacostia River. The measuring device is placed into the river, and it can report a result in 6 hours (to measure bacteria in a laboratory takes about 18-24 hours). This rapid measurement approach can inform source tracking in the Anacostia River and other rivers like the Potomac and Rock Creek.
“Getting a better understanding of bacteria sources and quantifying those sources using different tools and techniques will help inform management practices to control and mitigate bacteria pollution in District waters,” Seltzer wrote.
In the meantime, DOEE and NPS should work with haste to get warning signage up. The public’s health is at stake.
Alex says
Marchant Wentworth of Wentworth Green Strategies has written a study of this phenomenon, and he concluded that the sanitary sewers were leaking. Here’s a link to the study: https://wentworthgreenstrategies.com/leaking-sewers/
Gawain Kripke says
My dream, before I die, is to have a swim in a clean rock creek to cool off from a hot summer day. I think a swim in the Potomac isn’t very far off, given improving water quality there. But Anacostia and RC need more work.
B says
If you go into the Potomac upstream of Rock Creek, you should be fine. Rock Creek and the Anacostia are another story.
There are only two realistic explanations for the E. coli contamination in Rock Creek and its tributaries: leaks in the sanitary sewer systems and/or illegal connections to the storm sewer systems from sanitary sewer lines. Given the age of the lines and the very high readings of E. coli on dry days, leaks in the sanitary sewer lines seems more likely.
Unfortunately, few are advocating for DC Water to pick up the pace on fixing these lines. They are years behind schedule, and there’s no timetable to address the Interceptor. If only we had a effective watershed NGO and interested neighborhood advocates who were willing to push DC Water and the District’s government to clean up Rock Creek.
Gawain KRIPKE says
Do you think there are specific leaks/breaks that can be identified with better tools and research? Could this be a discreet problem we can solve? Or is the problem likely more comprehensive and requires extensive replacements and much bigger budgets and programs?
B says
DC Water does excellent work on repairing significant breaks to the lines. In my opinion, we are seeing the accumulation of years of deterioration. Many of the lines in question have long since passed their useful life. As a result, there are likely many small cracks that have a cumulative effect.
DC Water is doing the best they can with the resources available but we are far behind the curve on relining and replacement. Moreover, when these projects are planned, much of the energy from the public is being directed toward delay. We need a YIMBY equivalent for this vital infrastructure. Environmental NGOs, ANCs and neighborhood groups need to advocate for rehabilitation.
And if we are to see a cleaner Rock Creek, then the Main Interceptor Sewer needs to be rehabilitated, This is over 100 years old and likely the primary offender for the high readings reported in this article.
This is a problem we can solve, and it will take public pressure from those who care about Rock Creek to advocate for DC Water to direct resources to rehab these lines and to lobby for the work.
Green Eyeshades says
What or where is the “Main Interceptor Sewer?”
B says
It is the Rock Creek Main Interceptor (RCMI) and it roughly follows Beach Drive north to south. It collects the sewage from the trunk lines and directs it toward Blue Plains for treatment.
Green Eyeshades says
So if the Main Interceptor Sewer roughly follows the path of Beach Drive, I infer that it is “below” or “downstream” of Soapstone Creek, Broad Branch and Melvin Hazen.
If my inference is correct, then none of the e. Coli contamination in those three tributaries could be coming from the Main Interceptor Sewer. Is that right?
In particular, Soapstone Creek is “above” or “upstream” from the Main Interceptor Sewer, so e.Coli contamination in Soapstone Creek probably is not caused by leaks from the Main Interceptor Sewer.
I wonder why DC Water never once mentioned the Main Interceptor Sewer in the thousands of slides they have produced about the Soapstone Creek sewer project.
B says
The Rock Creek Main Interceptor extends from the DC Line through the Rock Creek Valley to the Rock Creek Pumping Station near 27th and K Streets NW. It captures the sewage from trunk lines extending from the neighborhoods to the west and east, including Fenwick Branch, Broad Branch, Normanstone, Soapstone, Dumbarton Oaks and several others. Thus it exists both upstream and downstream of Soapstone and Broad Branch. Leaks in the RCMI would not affect the trunk lines. It does, however, likely impact Rock Creek itself and may explain the exceptionally high E.coli readings at Joyce Road.
The most likely explanation for the high readings in Soapstone are small cracks and leaks in the line running underneath/adjacent to Soapstone Creek.
Reservation 630 (formerly Hazen) is a special case. There is no sewer line running under the length of the stream as there is in several other tributaries. However, a line cuts across the stream near its confluence with Rock Creek, and the stream monitoring readings actually take place below the line crossing.
The RCMI does not affect the age of the Soapstone trunk line, the erosion around its manholes and exposed pipes, or the likely numerous small cracks in the line. They are probably treated as separate projects.
Marchant Wentworth says
B is absolutely right about the need for more advocacy about the need to fix leaking sewers. The DC Council oversight hearing on DC Water is Feb 28 – I assume virtually. I plan to testify and urge others to do so as well. Cheers, Marchant Wentworth
Gawain KRIPKE says
Hi Marchant,
I hope you will post or share your testimony. I’d love to have it for future work. I sit on ANC3C and could take this up at some point.
Cheers,
Gawain
Marchant Wentworth says
Thanks Gawain: I will be glad to post it on my website. Cheers, M