Although the Ohio EPA is reporting improved water quality in the state’s largest rivers, the Mahoning River is still recovering from the impact of the Valley’s heavy industrial past.

The results of an EPA study launched in 2020 showed that 86 percent of the state’s large rivers are in good to excellent condition as compared to just 18 percent in the 1980s.

The report cites investments in agricultural soil conservation measures, improved wastewater infrastructure, and improved wastewater treatment as key reasons for the water quality improvements.

According to the Aquatic Life and Water Quality Survey of Ohio's Large Rivers report, rivers impacted by industrial legacy include the Tuscarawas, Mahoning, and Cuyahoga Rivers. These rivers also tended to have the highest levels of sediment contaminants.

Elevated metals and wastewater still have a significant environmental impact on the Mahoning River, especially in the sediments, according to the report.

Elevated sediment metal concentrations in the Mahoning River continue to impact bottom-dwelling small aquatic animals like dragonflies, stonefly larvae, snails, worms, and beetles.

Relatively high levels of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were also detected in the Mahoning River.

Concentrations reflected industrial and mining legacies with elevated heavy metal concentrations in Mahoning River sediment samples.

Results based on stream fish improved to good or excellent along much of the Mahoning River.  However, results were “marginal” in samples taken from the Mahoning River in Campbell which was once the site of steel mills.

On-going efforts, especially those directed at mitigating impacts from combined sewer overflows, better stormwater management, and removal of low-head dams have also been significant factors contributing to the recovery of the river, according to the study.