Large Rivers in Ohio Improved Water Quality From 1981 to 2021, Study Finds

A survey of nearly 1,400 free-flowing miles of large rivers in Ohio found that most of the rivers had improved water quality in 2021, compared to the 1980s. The Ohio Environmental Protection Agency (Ohio EPA) said the amount of miles of rivers with good to excellent water quality increased from 18% in the 1980s to 86% in the 2020-2021 survey.

Officials at the Ohio EPA studied 1,372 free-flowing miles of large rivers at 156 sites. The biological census included reviewing water quality and sediment chemistry, as well as analyzing fish tissues for contamination.

The results were published in a report, “Aquatic Life and Water Quality Survey of Ohio’s Large Rivers.” One of the biggest findings was that water quality was good to excellent in 86% of the river miles, compared to just 18% in the 1980s. Researchers found declines of ammonia, total phosphorous and lead in the water and less mercury, lead, arsenic, and other contaminants in fish, The Associated Press reported.

According to the Ohio EPA, these improvements resulted from improved wastewater treatment infrastructure and agricultural soil conservation efforts.

But the rivers still face ongoing problems, include over-enrichment from excess phosphorus and nitrogen in the water. The report also found legacy pollution from coal mining in the water and sediment. 

“The same sorts of things that happen in western Lake Erie, where we have the algae blooms, those same forces are enriching our rivers,” said Bob Miltner, lead author of the study and a senior scientist at the Ohio EPA, as reported by The Columbus Dispatch. “Our rivers, they’re supposed to be productive in the Midwest, it’s a productive environment. But they’re a little bit too enriched. And so part of what we want to do is back that off.”

The survey showed that large rivers were warming, from an average of 20.5 degrees Celsius in the 1980s to an average of 23.2 degrees Celsius in the most recent report. Ohio EPA research has shown the water temperatures to be on a steady incline with each decade.

One large river in the study, the Mohican River in north-central Ohio, which is a popular spot for outdoor recreation, showed a significant decline in water quality because of over-enrichment.

The study did not include the Ohio River, The Columbus Dispatch reported. The survey was also completed in 2020-2021, before a train carrying hazardous chemicals derailed in East Palestine, Ohio, which contaminated Lesley Run and Sulphur Run creeks. Cleanup in the area and the Ohio River continues.

The report is part of the H2Ohio initiative created by Ohio Governor Mike DeWine in response to harmful algal blooms in Lake Erie. Following the report’s findings of continued over-enrichment problems, DeWine noted that officials will work with farmers through H2Ohio and look to improve stormwater management systems to mitigate excess phosphorous and nitrogen in waterways. 

Earlier this year, DeWine also proposed a H2Ohio Rivers Initiative to further improve river water quality through a river restoration program, dam removal, a litter cleanup program, and efforts to remediate waters affected by acid mine drainage from old coal mines.

“This proposed initiative will work to preserve and protect the health of Ohio’s rivers and the land and wildlife habitats alongside them by cleaning up polluted waterways, strategically removing dams, and restoring rivers across the state to their former glory,” DeWine said in a statement.