Health and Human Services Secretary Robert F. Kennedy Jr. posted pictures to social media on Sunday showing him with his grandkids in a creek where swimming is prohibited due to high levels of dangerous bacteria.

Rock Creek is located in Washington, D.C., and is part of the National Park Service. According to the NPS website, the 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."

"Scrambling in and out of the creek can also erode stream banks, which can negatively impact habitat for the park’s aquatic wildlife," NPS said.

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In his post on X, Kennedy said, "Mother’s Day hike in Dumbarton Oaks Park with Amaryllis, Bobby, Kick, and Jackson, and a swim with my grandchildren, Bobcat and Cassius in Rock Creek."

The post was flagged by readers on the social media platform, and now there is a label on it that reiterates that swimming in the creek is prohibited.

Some X users pointed out that there is signage that warns visitors not to swim in the water.

The NPS website does not say why the creek has high levels of bacteria or if anything is being done to counteract it.