The Mahoning River (upper) Watershed TMDL
The upper Mahoning River Watershed Total Maximum Daily Load (TMDL) report was approved by U.S. EPA on September 28, 2011. TMDL reports identify and evaluate water quality problems in impaired water bodies and propose solutions to bring those waters into attainment with water quality standards.
The upper Mahoning River watershed is located in northeastern Ohio. The upper Mahoning River watershed, which is the area upstream of the confluence of Duck Creek in Leavittsburg, drains approximately 539.8 square miles and is located in Portage, Mahoning, Trumbull, Columbiana, Stark, and Geauga counties. Land use in the upper Mahoning River watershed is a mix of agriculture, rural residential and urban land uses. Significant public reservoirs used for recreation are Berlin Lake, Lake Milton, M.J. Kirwin Reservoir, Deer Creek Reservoir and Dale Walburn Reservoir. The Mahoning River mainstem is a source of public drinking water for the cities of Newton Falls and Sebring; the city of Alliance has a drinking water intake within Deer Creek Reservoir.
Ohio EPA sampled water quality in the watershed in 2006. Only 38 percent of the sites on the Mahoning River fully met aquatic life use goals and five percent met recreation use goals. Problems were an excessive amount of fine sediment in the channels and nutrient enrichment from runoff and other drainage from cropland and animal farming, high nutrients in waste water, substantial habitat degradation associated with dam impoundment and a generally unnatural stream flow regime from the regulated flows caused by the large dam releases. The major sources of the bacteria loading are cropland drainage and home septic systems, with lesser contributions from waste water systems (both CSOs and WWTPs) and urban runoff.
TMDLs in selected areas of the watershed are calculated for E. coli bacteria, total phosphorus, and sedimentation and habitat. Recommendations include new concentration limits for eight facilities, adoption of conservation practices on cropland, overall better treatment of decentralized waste water, improving habitat through a more natural approach to drainage maintenance and better dam release protocols. The report recommends increased inspections and subsequent enforcement regarding home septic systems that do not comply with local codes and implementing conventional management practices to abate pollutant loading from cropland and urban landscapes.
The TMDL Report
Many of the documents referenced in the TMDL report can be found under Forms and Publications page.
Supplemental Information
The folowing documents provide background information on the upper Mahoning River watershed.
- Fact sheet [PDF 690K]
- Biological and Water Quality Study of the upper Mahoning River and Selected Tributaries, 2006, Columbiana, Mahoning, Portage, Stark and Trumbull Counties, Ohio.
For further information, please go to the 2006 Upper Mahoning River Water Quality Monitoring page.
For more information please contact:
Bill Zawiski
Ohio Environmental Protection Agency
Northeast District Office
2110 East Aurora Road
Twinsburg, Ohio 44087
bill.zawiski@epa.state.oh.us