One of the less common forms, methylmercury, is the most threatening to people. Mercury persists in the environment in a few different chemical forms. "Especially when it comes down to something as important as the ability to eat the fish and remain healthy."įor all that's complicated about regulating mercury, one thing is clear: It's a potent neurotoxin that is particularly dangerous to children. "What is that telling the public?" said Jason Flickner, director of the Indiana-based Lower Ohio River Waterkeeper. Yet the agency's most recent annual report says the "entire river is impaired for fish consumption due to dioxin and PCBs, but fully supports fish consumption for mercury." Myers Locks and Dam in southern Indiana to where the river empties into the Mississippi River) due to mercury concerns. The ORSANCO fish advisory website lists seven species - sauger, black bass, freshwater drum, white bass, striped bass, hybrid striped bass and flathead catfish - that shouldn't be eaten more than once a month from one 135-mile section of the Ohio River (from the John T. While ORSANCO and state authorities are bogged down in disagreements over the relative threat of atmospheric and wastewater sources and whether states should work through ORSANCO to tighten regulations across the watershed, environmental advocates say the public is worse off for having to sort through the mess. Army Corps of Engineers)Īn environmental scientist who has seen preliminary results said the study has flaws, though it's not clear if those concerns will make it into the final version expected next month. Myers Locks and Dam in southern Indiana to where the river empties into the Mississippi River due to mercury concerns. ORSANCO lists seven species that shouldn't be eaten more than once a month from the John T. The report isn't yet published, but a presentation delivered to an ORSANCO committee meeting in October 2019 said 11 percent of the mercury in the Ohio River main stem comes from wastewater discharges throughout the watershed, including tributaries. In 2016, commission staff launched a broad accounting of atmospheric and wastewater mercury sources across the Ohio River watershed. ORSANCO's strengths, Harrison said, are monitoring and research. The states agree to work through ORSANCO as a collaborative body to work globally for the Ohio River basin." "ORSANCO doesn't set rules for the states," said Richard Harrison, the agency's executive director. ORSANCO has moved away from regulation, a path the agency said reflects the reality that it doesn't have the same authority as its member states' environmental agencies or the U.S. Industries arguing against tighter water standards say that atmospheric sources are a bigger problem, and much of the mercury in their wastewater is in a chemical form unlikely to move through the food chain into fish. Mercury takes a complicated path from industrial and natural sources through water and air to humansĮnvironmental groups have looked to ORSANCO to tighten mercury standards on wastewater discharges. The tension between blaming airborne or wastewater sources is one factor among many that have played into controversial decisions around mercury over the past decade at the Ohio River Valley Water Sanitation Commission - an interstate water quality agency created in 1948 when the Ohio River was an open sewer for cities and factories and the Clean Water Act was still decades away. The industries say the problem lies in regional and global air emissions, but the legal levers there aren't as easy to pull. There's a legal pathway for further ratcheting down mercury releases directly to the river, but the regulated industries say they already meet strict permit requirements and that path has hit diminishing returns. Fish are the most important source of exposure to humans. The efforts so far to get a handle on it have spurred a patchwork of state rules that leave it up to consumers whether it's worth the risk to eat their catch of the day. The mercury eventually settles on land and flows into water.įiguring out how much of the toxic is coming from local industries or wind currents remains a challenge. While coal-fired power plants, chemical manufacturers and other facilities along the Ohio River are piping mercury directly into the river and there's a permitting process to regulate that, the more significant source appears to be mercury blown into the atmosphere from smokestacks - both locally and across the globe from mining, energy and other industries. But the multi-state agency tasked with keeping the waterway clean hasn't tightened controls on this pollution because it doesn't have the authority to do so. Mercury, which damages young brains, is flowing through industrial wastewater into the Ohio River.
0 Comments
Leave a Reply. |