All in Germ-theory skeptic RFK Jr. goes swimming in sewage-tainted water The National Park Services bars all swimming and wading due to the health hazard. Beth Mole – May 12, 2025 12:27 pm | 13 Credit: Kennedy Credit: Kennedy Story text Size Small Standard Large Width * Standard Wide Links Standard Orange * Subscribers only   Learn more When you don’t believe in germ theory, the world is your oyster—or maybe your bathtub. Over the weekend, America's top health official, Robert F. Kennedy Jr., shared pictures on social media of himself fully submerged in the sewage-tinged waters of Rock Creek in Washington, DC. His grandchildren were also pictured playing in the water. The creek is known for having a sewage overflow problem and posing a health hazard to any who enter it. The National Park Service, which manages the Rock Creek Park, strictly bars all swimming and wading in Rock Creek and the park's other waterways due to the contamination, specifically "high levels of bacteria." A notice on the NPS website advises "Stay Dry, Stay Safe," warning, "Rock Creek has high levels of bacteria and other infectious pathogens that make swimming, wading, and other contact with the water a hazard to human (and pet) health. Please protect yourself and your pooches by staying on trails and out of the creek. All District waterways are subject to a swim ban—this means wading, too!" In images shared on social media, Kennedy can be seen getting fully underwater, including his head, and then splashing around with several of his grandchildren. Kennedy, who does not have any background in medicine or science, was a long-time anti-vaccine advocate before President Trump appointed him to be health secretary. In a 2021 book, Kennedy indicated that he does not believe in germ theory, the fundamental concept that microscopic pathogens, such as those abundant in sewage, are the cause of disease. RFK Jr. can be seen completely submerged in the water in this picture shared on social media. Credit: Kennedy The urban creek is contaminated mainly because of the numerous century-old municipal sewer lines that run under the park. These lines have cracked over time and leak sewage, according to Marchant Wentworth, an environmental consultant who submitted a report on the problem to the DC Council in 2021. In an opinion piece in The Washington Post, Wentworth wrote about the report's findings and the dangers of the creek's water. While sewage pollution is most acute after rains, experts found that the creek's bacterial counts—particularly E. coli counts—were dangerously high all the time. Wentworth wrote: For example, on July 14, 2015, the DC Department of Energy and the Environment found bacteria levels over 2,420 times the most probable number of colonies in 100 milliliters (MPN). This is far in excess of the Environmental Protection Agency standard of 410 MPN. On that same day, no rain was detected in any of three rain gauges around the city. Similarly, on Aug. 27, 2016, at the water sampling site maintained by the U.S. Geological Survey, the bacteria level was measured at an astoundingly dangerous 40,000 MPN. No rain was reported either that day or the day before. In March, the NPS announced that it had completed an environmental assessment and approved a proposal by DC Water to construct a tunnel to try to reduce sewage overflow from getting into the creek. The tunnel will be along Piney Branch stream, a tributary to Rock Creek. "Currently, around 40 million gallons of stormwater combined with untreated sewage overflow into Piney Branch each year," the NPS wrote. It's unclear where Kennedy and his grandchildren went swimming in Rock Creek over the weekend. But he noted in his social media post that they had also been hiking in Dumbarton Oaks Park, an area that is downstream of Piney Branch. Beth Mole Senior Health Reporter Beth Mole Senior Health Reporter Beth is Ars Technica’s Senior Health Reporter. Beth has a Ph.D. in microbiology from the University of North Carolina at Chapel Hill and attended the Science Communication program at the University of California, Santa Cruz. She specializes in covering infectious diseases, public health, and microbes. 13 Comments