^tDS% o PRO^° 36 JNONPOINT source success story Voluntary Conservation Programs Reduce Bacteria Concentrations in Upper Salt Creek Waterbody Improved Elevated Escherichia coli (E. coli) levels, contributed by grazing and hay production, resulted in the impairment of Upper Salt Creek and placement on Oklahoma's Clean Water Act (CWA) section 303(d) list of impaired waters in 2010, Implementation of conservation practice systems (CPs) promoted better quality grazing lands and decreased E. coli levels in the creek. As a result, Upper Salt Creek was removed from Oklahoma's 2016 CWA section 303(d) list for E. coli. Upper Salt Creek now partially supports its primary body contact (PBC) designated use. Problem Salt Creek flows through Osage County before dis- charging to the Arkansas River in northern Oklahoma (Figure 1). Its watershed is in the Flint Hills Ecoregion and is comprised of tallgrass prairie on rolling hills with relatively steep, narrow valleys composed of shale and cherty limestone with rocky soils. Land use in the 185,000-acre watershed is primarily grasslands (85 percent) for beef cattle and hay produc- tion. About 6 percent of the watershed is developed land (primarily for highways and roads), 2 percent is forested, and less than 4 percent of the watershed is cropland. Grazing and hayland management contributed to excess E. coli in Salt Creek. The upper segment of Salt Creek (43.97 miles) was listed as impaired for bacteria in 2010 when the geometric mean of samples violated Oklahoma's water quality standards. An Oklahoma stream is considered to violate the E. coli standard when the geometric mean of recreation season samples exceeds 126 colony-forming units per one hundred milliliters (CFU/lOOml). On the basis of these assessment results, the Oklahoma Conservation Commission (OCC) added the upper segment of Salt Creek (OK621200040010_10) to the 2010 CWA section 303(d) list for nonattainment of the PBC designated beneficial use. Story Highlights Landowners in the watershed worked with the Osage County Conservation District, the U.S. Department of Agriculture Natural Resources Conservation Service (NRCS), and the OCC to implement CPs through Oklahoma NRCS's Environmental Quality incentives Program (EQIP) and general conservation technical assistance program, and through the OCC's Locally Led Cost Share Program (LLCP). From 2002 to 2017, landowners improved many acres of pasture and hay meadows, which reduced runoff of sediment and other pollutants by decreasing erosion and better utilizing available grazing lands (Table 1). Figure 1. Salt Creek is in Osage County, Oklahoma. ------- Table 1. CPs installed in the Salt Creek watershed. Practice name Amount installed Upland wildlife habitat management 21,975 acres Use exclusion 89 acres Prescribed burning 22,000 acres Pest management 25,051 acres Forage harvest management 754 acres Conservation crop rotation 512 acres Prescribed grazing 84,316 acres Conservation tillage 902 acres Pond 8 Pasture and hayland planting 644 acres Results The OCC documented improved water quality in Salt Creek through its statewide nonpoint source Rotating Basin Ambient Monitoring Program. Improvements were due to landowners implementing CPs. The installed practices worked to decrease E. coli concentrations. Monitoring data compiled for the 2010 integrated report had showed excessive E. coli in Salt Creek (geomean of 282 CFU exceeded the state criteria of 126 CFU). By 2016, E. coli values had decreased to a geomean of 25 CFU. This decreasing trend continues through the 2020 assessment (Figure 2). On the basis of these data, Upper Salt Creek was removed from the Oklahoma CWA section 303(d) list for E. coli in 2016. Salt Creek is now in partial support of its PBC beneficial use. Partners and Funding The OCC monitoring program is supported by U.S. Environmental Protection Agency's (EPA) CWA section 319 funding at an average annual statewide cost of $1 million. Approximately $500,000 in EPA 319 funds support statewide water quality educational efforts through Blue Thumb. Approximately $130,000 of these federal and state matching funds have been devoted to Salt Creek. Working in partnership with local conservation districts, NRCS supplied approxi- mately $324,000 for implementation of CPs in the watershed through NRCS EQIP. The LLCP provided $16,084, which was matched by $30,436 from land- owners. Many practices were funded by landowners based on recommendations through NRCS general technical assistance and conservation planning. Upper Salt Creek E. coli max = geomean 1000 1 900 o S 800 ¦t! 700 3,500 282 3,500 296 2,500 25 2,000 41 600 E 500 400 _2 300 200 100 2010 2012 2016 2020 Figure 2. E. coli decreased in the upper segment of Salt Creek as producers improved pasture management. ^£DSrX PRO^° ro s o U.S. Environmental Protection Agency Office of Water Washington, DC EPA 841-F-19-001Y October 2019 For additional information contact: Shanon Phillips Oklahoma Conservation Commission 405-522-4728 • shanon.phillips@conservation.ok.gov ------- |