The Little Miami River (lower) Watershed TMDL
The lower Little Miami River Watershed Total Maximum Daily Load (TMDL) report was approved by U.S. EPA on March 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 lower Little Miami River watershed is located in southwest Ohio. The 602-square-mile TMDL project area encompasses the Little Miami River watershed from below Caesar Creek to the mouth, excluding the East Fork Little Miami River.
Land use in the watershed is predominantly agriculture (40% cropland, 11% pasture) and forest (30%). About 17% of the watershed is developed or urban land, mostly in the southern portion when current land development is most rapid.
Water quality monitoring in 2007 identified impairments of aquatic life and recreational uses. The Little Miami River itself displayed exceptional quality, while the tributaries were generally of a lower quality. Overall, aquatic communities met water quality goals at 66% of the sites surveyed, partially met standards at about 26%; approximately 9% of the sites did not meet any of the quality goals. About 30% of the sites failed to meet bacteria water quality standards.
The two primary causes of aquatic life impairment are the high proportion of fine sediment in the channel and the extremely low water levels due to a drought year. Other stressors include degraded habitat from agricultural drainage and the "armoring" of the stream channel in urban areas; nutrient enrichment from wastewater plant effluent and cropland runoff, and oxygen demanding substances from inadequately treated storm water at the former ABX Airpark and combined sewer discharges within the Metropolitan Sewer District (MSD). Sources of bacteria are wastewater emanating from sanitary sewer and combined sewer overflows, inadequate treatment from home septic systems, and runoff of bacteria-laden crop fields where manure or sludge are likely applied. TMDLs are calculated for E. coli bacteria, total phosphorus, chemical oxygen demand, total suspended solids, and sedimentatiion and habitat.
Recommendations include point source controls on the airpark, MSD's combined sewer system, and the Blanchester wastewater treatment plant. Nonpoint source actions include improving home septic systems and implementing conventional management practices that are designed to abate pollutant loading from cropland and urban landscapes.
The TMDL Report:
Many of the documents referenced in the TMDL report can be found on the Forms and Publications page.
Supplemental information:
- Fact Sheet [PDF 416K]
- Biological and Water Quality Study of the Lower Little Miami River and Selected Tributaries including the Todd Fork Subwatershed, 2007. Clermont, Clinton, Hamilton, and Warren Counties, Ohio.
For more information contact:
Gregg Sablak
Ohio Environmental Protection Agency
Division of Surface Water
P.O. Box 1049
Columbus, Ohio 43216-1049
gregg.sablak@epa.state.oh.us