Study of Minor Great Black Swamp Tributaries Released

Public Comment Period Open through June 29  

Today, Ohio EPA today released a study examining water and sediment chemistry, habitat, fish, and other aquatic life from 50 small streams that flow into the Maumee River in northwest Ohio. These small streams drain approximately 1,040 square miles in portions of Defiance, Fulton, Hancock, Henry, Paulding, Putnam, and Wood counties.  

Ohio EPA is accepting public comments about the study, which can be found online, through June 29, 2020.

The study shows that most small Great Black Swamp tributaries have healthy fish and macroinvertebrate populations. Overall, water quality in the smaller streams has improved compared to results from a previous study more than two decades ago.

Eighty-nine percent (80 of 90) of the stream locations sampled are meeting the aquatic life goals supporting a variety of fish and insect species. Sensitive species such as the Eastern sand darter have re-established throughout the watershed, indicating improving stream conditions.

Lower concentrations of mercury in fish caught in Bad Creek, North Turkeyfoot Creek and South Turkeyfoot Creek have led to less strict fish consumption advisories for channel catfish, yellow bullhead catfish, and common carp.

The study also found many streams are not meeting human recreation-based water quality standard for E. coli bacteria. Silt buildup caused by streambank erosion and soil runoff around agricultural fields was common as was channelization for agricultural drainage. Elevated nutrient levels in the creeks are concerning, particularly for the village of Delta, which draws drinking water from Bad Creek. These smaller streams discharge nutrients to the Maumee River and then to Lake Erie where they contribute to harmful algae blooms that occur annually in the Western Lake Erie Basin.

The study recommends targeting areas where the highest nutrient enrichment was found to reduce loads of phosphorus and nitrogen. Suggestions include continuing focus on improving fertilizer applications to crop fields, improving livestock manure management, conservation tillage, and improving riparian buffers around agricultural fields. Additionally, unsewered communities with failing septic systems are discharging bacteria and nutrients that impact local water quality.

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

Further details about the study, data, and maps are contained in the report. The study is the second step in Ohio EPA’s five-step Total Maximum Daily Load process.

Findings in the report along with public comments received 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, whichever may be necessary to address water quality impairment at any given location. 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. June 29, 2020.


The Ohio Environmental Protection Agency was created in 1972 to consolidate efforts to protect and improve air quality, water quality and waste management in Ohio. Since then, air pollutants dropped by as much as 90 percent; large rivers meeting standards improved from 21 percent to 89 percent; and hundreds of polluting, open dumps were replaced with engineered landfills and an increased emphasis on waste reduction and recycling.

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