09/30/2026
DID YOU KNOW❓❓❓
Maryland recommends that adults eat no more than ONE meal per month of sunfish caught in Antietam Creek, including bluegill. Children age six and under should eat no more than ONE meal every OTHER month because of PFOS contamination.
For Conococheague Creek, adults should eat largemouth or smallmouth bass no more than ONCE every OTHER month. Children age six and under are advised NOT TO EAT THOSE BASS AT ALL.
That obviously got us looking more closely at what the Antietam, Conococheague, and Beaver Creek watersheds have been dealing with.
PFAS: PFOS is one of thousands of chemicals in the larger PFAS family. These man made chemicals have been used for decades in things like nonstick coatings, waterproof and stain-resistant products, food packaging, and firefighting foam. Many PFAS are extremely persistent, which is why they are often called forever chemicals. Once they get into the environment, they remain there for years and build up in wildlife, including fish.
A study of smallmouth bass found especially high PFAS levels in fish collected from the Potomac at the mouth of Antietam Creek. The average concentration in their blood plasma was 447 ng/mL, the highest of the four Chesapeake Bay watershed sites studied. That was more than FOUR times the level measured at the South Branch Potomac site in West Virginia and more than SIX times the level at Pine Creek in Pennsylvania.
PFOS is a human health concern. The EPA now considers it likely to be carcinogenic to humans when swallowed, with studies showing a link with liver cancer. Research has linked PFOS exposure to problems involving cholesterol, the liver, pregnancy, and the immune system.
PCBs: Another class of persistent industrial chemicals that remain a concern in parts of our waterways. PCBs were banned in the United States in 1979, but they do not easily break down and remain stored in sediments for decades. Over time, they can be taken up by small organisms and move through the food web, including into fish. There has been improvement in the Conococheague watershed, where testing showed PCB concentrations had declined enough for Maryland to remove its PCB impairment listing in 2024.
Nutrients and bacteria: Our watershed also faces challenges from both excess nutrients and bacterial pollution. Phosphorus from sources such as runoff and wastewater can act like fertilizer in streams. At the same time, bacteria from sources such as animal waste, failing septic systems, and stormwater runoff can also affect recreational safety. Antietam Creek and Conococheague Creek both have state cleanup plans addressing bacterial pollution, while Antietam also has a phosphorus cleanup plan.
Pesticides and other chemicals: USGS research near the Antietam–Potomac confluence found herbicides including atrazine, simazine and metolachlor, along with pharmaceuticals and hormones. And honestly, there is still a lot we do not know about what long term exposure to this mix of chemicals could mean for the creek and the wildlife living in it.
DDT contamination: Elevated DDT was found in Antietam Creek sediment in 1976 and ultimately traced to Central Chemical. Cleanup work at that site continues to this day, although it's not quite clear how much remains in the creek.
Taken together, these pollutants are more than an environmental concern. PFAS, PCBs and DDT have all been linked to serious health effects involving cancer, the liver, immune system, reproduction, pregnancy and development, while bacterial contamination can cause illness and infections.
Our waterways already face such a complicated mess of pollution challenges. As these new water intensive industries continue to be proposed, I believe we all need to understand what will enter our wastewater system and how they intend to treat it. Hagerstown’s own planning documents mention “contaminants from blow down” in relation to data centers, but conveniently do not explain what those contaminants may be or how they would be handled. This is especially worth paying attention to when the city is already spending resources to monitor PFAS in its wastewater system. I will include links in the comments for anyone interested in doing more research on their own.
This one is also very personal for me. I grew up exploring Antietam Creek, swimming, tubing and fishing, including around an area where testing consistently finds high levels of f***l bacteria 🤢 My parents gave me the freedom to explore, and those days helped me fall in love with the outdoors. But after learning this about a place I spent so much time in is upsetting, and it’s part of why I feel so obligated to share this information now.
Thankfully, we also have some incredible local nonprofits working to protect and restore these creeks, including the Antietam-Conococheague Watershed Alliance, Beaver Creek Watershed Association, Potomac Riverkeeper Network, Catoctin Land Trust, and Seneca Valley Trout Unlimited. The work they do is badly needed, and honestly, it is often underappreciated and underfunded for how much they contribute to the health of our local waterways.
And on a lighter note, these creeks are still full of life worth protecting. One of our favorite little residents is the rainbow darter, a tiny, colorful fish found throughout Washington County. The males develop bright blue, orange and red colors during breeding season. They spend much of their time around rocky riffles and cobble on the stream bottom.
