Study of Rocky River tributaries analyzes fish, E. coli levels and more

The Ohio EPA released a study examining water and sediment chemistry, habitat, fish and other aquatic life from 28 named and unnamed rivers and streams that flow into the Rocky River. These small streams drain approximately 294 square miles in portions of Cuyahoga, Lorain and Medina counties.

The east branch of the Rocky River begins in North Royalton, near State and Wallings roads, and flows through Richfield and Hinckley townships.

Of the 119.6 stream miles assessed, 79 percent (94 of 119 miles) of stream locations sampled were found to fully support existing and recommended aquatic life uses.

Lower concentrations of mercury in fish caught throughout the study area have led to a fish consumption advisory recommendation of eating no more than one meal per week for most species and most fishable waters within the Rocky River basin.

The exceptions were limited to a smallmouth bass taken from the west branch of the Rocky River and rock bass taken from the east and west branches. The smallmouth bass showed elevated mercury concentrations in the past, and the existing advisory of one meal per month is recommended.

In contrast, the rock bass had falling levels of mercury and now receives a recommendation of one meal per week, replacing the previous, more stringent advisory of one meal per month. 

The study also found many streams not meeting the human recreation-based water quality standard for E. coli bacteria. Bacterial contamination was present during both wet and dry weather events. These sources include combined sewer overflows, sanitary sewer overflows, urban stormwater, treated wastewater discharges and failing home sewage treatment systems. 

The study found that 10 streams or segments of the 28 water bodies evaluated are not meeting attainment for aquatic life uses. The leading sources of this impairment were modifications to the waterway and stormwater from urban and suburban landscapes. Habitat alterations were the next leading cause of impairment. 

The study is designed to assess the effects of various land uses, evaluate the influences of agricultural, industrial and commercial discharges and spills and assess the performance of permitted wastewater treatment plants.

It also evaluates the quality of fish and macroinvertebrate communities in streams, compares results with historic conditions and determines if streams are meeting designated aquatic life and human recreation uses. 

More details about the study, data and maps are contained in the report.

Findings, along with public comments, will be developed into a Total Maximum Daily Load report, which is a plan to improve water quality in the watershed through potential permit limits on regulated dischargers and/or nonpoint source runoff reduction projects.

Ohio EPA works with local communities and watershed groups to implement projects and strategies to achieve water quality goals.

To comment on the study, email EPATMDL@epa.ohio.gov or write to: TMDL Program, Ohio EPA Division of Surface Water, P.O. Box 1049, Columbus, OH 43216-1049. Comments are due by 5 p.m. on Friday, Aug. 21.