March 9, 2026 11 min read Add Us On Google Add SciAm Dredging up a toxic past in the Cape Fear River A proposed $1.3-billion U.S. Army Corps of Engineers port expansion in North Carolina threatens to unearth decades of “forever chemicals.” The government’s initial plan: don’t test the mud By Patrick Sisson edited by Eric Sullivan An Army Corps boat pumps sediment off the North Carolina coast. Deepening Wilmington’s navigation channel to accommodate massive cargo ships requires displacing millions of cubic yards of mud and sand. Jeffrey Greenberg/Universal Images Group via Getty Images Taking a blood sample from a wild American alligator is not a clinical procedure. North Carolina native Kemp Burdette describes the process as an “all-hands-on-deck” situation. After rolling up on the gator in a boat and tossing a hook and a lead weight tied to a heavy-gauge fishing line across the beast’s backside, you reel until the hook catches and flips the creature. Then comes the all-hands part. Ideally a small group of people tag-team to hold the animal down—it will chill out, but just watch for the tail—drape a towel over its eyes, duct tape its mouth, and prick between the thick armor with a needle. “Alligator jaws have an incredible amount of crushing force but not very many pounds of opening force,” Burdette says. “You can actually hold an alligator’s mouth shut, even a big one.” Burdette knows this because the Cape Fear River is his jurisdiction. A former Navy search and rescue swimmer who grew up sloshing around swamps and backwaters, he’s a Riverkeeper, the local leader of the national Waterkeeper environmental organization dedicated to saving the region’s 200-mile riverine ecosystem. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing . By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. He wrestles these apex predators not for sport but to hunt for a microscopic threat: PFAS, or per- and polyfluoroalkyl substances. Burdette worked with a team of North Carolina State University scientists who measured PFAS concentration in the blood of alligators and found that it was correlated with immune issues in the animals—another worrying sign in a decades-long history of PFAS poisoning in Cape Fear. First brought to the public eye by investigative stories in Wilmington, N.C.’s local paper StarNews in 2017, GenX—a PFAS substance used to produce Teflon coating, also known as hexafluoropropylene oxide dimer acid—has saturated the region’s watershed and drinking water for years. It has made the region a hotbed of investigation, research and regulatory efforts around the dangerous “forever” chemicals. But a federal megaproject may stir up even more trouble. The U.S. Army Corps of Engineers has proposed a $1.3-billion plan to enlarge the Cape Fear River—using a fleet of boats, barges and construction equipment to unearth 35 million cubic yards of soil and sand. Roughly half of that material would be placed on nearby beaches and habitat-restoration sites; the rest would be transported offshore for disposal. The dig would deepen the harbor from 42 to 47 feet and, in some places, stretch the width of the river by the length of two football fields. It’s a massive logistical bet designed to fit ever larger post-Panamax ships—whose size corresponds to the dimensions of the recently extended Panama Canal, which expanded in 2016—and to keep the local maritime industry competitive in a global supply chain obsessed with efficiency. In estuaries like the one at Cape Fear, deepening a channel can allow tides and storm surges to push farther upriver, bringing salt water with them. That’s one reason opponents argue the project could unsettle contaminated sediment and amplify flooding as sea levels rise—changes that, in their view, could worsen the region’s substantial PFAS problem. After months of escalating community concern, the plan was temporarily paused in January. And on February 24 the standoff escalated: the North Carolina Department of Environmental Quality formally objected to the draft Environmental Impact Statement (EIS) from the Corps, stating in a press release that the proposal failed to supply “sufficient information about PFAS, flooding, and placement of dredged material.” Both the Corps and the North Carolina State Ports Authority said in written statements that they are deciding the next steps to take. The Corps could still reach an agreement through a mediation process with state environmental officials, according to Jedidiah Cayton, a Corps public affairs specialist. “If the Army Corps of Engineers can make changes to its proposal to protect people