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Leona River

Leona River. Potential Loads and Sources for Bacteria and Nitrates. Texas Institute for Applied Environmental Research Stephenville, Texas June 4, 2013. Acknowledgements. Lead Agency - Texas Soil & Water Conservation Board Support provided by Nueces River Authority

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Leona River

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  1. Leona River Potential Loads and Sources for Bacteria and Nitrates Texas Institute for Applied Environmental Research Stephenville, Texas June 4, 2013

  2. Acknowledgements • Lead Agency - Texas Soil & Water Conservation Board • Support provided by Nueces River Authority Texas A&M Dept Soil & Crop Sciences & Spatial Sciences Laboratory

  3. Modeling to Evaluate Water Quality and Sources • Load Duration Curves (LDCs) • SELECT (Spatially Explicit Load Enrichment Calculation Tool)

  4. Load Duration Curves (LDCs) Purpose: • To define flow conditions under which desired loads are exceeded • Define potential load reductions

  5. Load Duration Curves LDCs use the following: • Daily stream flow data • Allowable or desired concentration • Measured concentrations and flows

  6. Locations for Load Duration Curve Development USGS 8204005 TCEQ 12988/12989 USGS 8204250 TCEQ 12987 USGS 8204500 TCEQ 12985

  7. Load Duration Curves Allowable or desired concentration Primary Contract Recreation Standard E. coli 126 cfu/100 mL General Use Screening Level Nitrate 1.95 mg/L

  8. Assessment Bacteria

  9. Assessment Nitrates

  10. Load Duration Curves Steps - • Develop Flow Duration Curve (FDC) (time history of daily flow data) • Calculate allowable loads (criterion or screening level) • Estimate measured loads (measured concentrations and flow) • Compare measured to allowable loads

  11. Flow Duration Curves (FDCs) • Daily stream flows for a given time period ranked highest to lowest

  12. Use of LDCs for Source Identification High Flows Moist Mid- Range Dry Low Flows Source Graphic: http://www.kdheks.gov/tmdl/basic.htm#data The Kansas Department of Health and Environment

  13. FDC Leona River near Uvalde 1970 – 2010

  14. LDC E. coli - Leona River near Uvalde Criterion 126 cfu/100 mL

  15. Potential Reductions % Reduction = (Allowable – Measured) Measured * 100 Averaged by Flow Category

  16. LDC E. coli Leona River near Uvalde

  17. Average Percent Reduction E. coli NA indicates not applicable, because most low flows were zero flow.

  18. LDC NitratesLeona River near Divot E. coli data 1972 – 2012

  19. Average Percent Reduction Nitrate NA indicates not applicable, because most low flows were zero flow.

  20. Load Duration Curve - Summary Potential Reductions Needs • Bacteria & Nitrate • primarily at higher flows associated with rainfall-runoff • Bacteria • lower flows indicated near Batesville • Nitrates • lower flows indicated near Divot

  21. Load Duration Curves Questions ??s

  22. Modeling Bacteria Sources SELECT(Spatially Explicit Load Enrichment Calculation Tool) • Developed by Dept. of Biological and Agricultural Engineering and Spatial Sciences Laboratory at Texas A&M University by Dr. R. Karthikeyan, Dr. R. Srinivasan and others

  23. SELECT • Identifies POTENTIAL bacteria loadings by subwatershed • Based on spatial data, such as: • Land use • Soils • Stream network • Animal density • Population information

  24. Spatial Science Laboratory Texas A&M University in College Station • Satellite imagery • Aerial photos • Ground control points • Ground verification

  25. Input Data • Population & Household Densities • Census data • Livestock Densities • County Agricultural Statistics (USDA) • Wildlife • Resource Experts (TPWD & others) • Domestic & Feral Animals • Resource Experts (TPWD & others)

  26. Permitted Facilities • Wastewater Treatment Facilities • Uvalde • Batesville • US Fish & Wildlife Service National Fish Hatchery • Concentrated Animal Feeding Operations • Chaparral Cattle Feedlot (Uvalde) • Live Oak Feedlot (Batesville)

  27. 17% 2% 2% 80% 11% 4% 98% 84% 99.8% 32% 68% 5% 95%

  28. CAFOs Chaparral Cattle Feedlot south of Uvalde (10,000 permitted head) Live Oak Feedlot southeast Batesville (8,000 permitted head) Input E. coli production rate 1E10 cfu/animal/day assuming “treatment” efficiency of 80%

  29. Cattle #s in Leona Uvalde 5,516 Zavala 10,566 Frio 6,418 Input Fecal Production Rate Cattle 10E10 cfu/animal/day

  30. Cattle #s in Leona Uvalde 5,516 Zavala 10,566 Frio 6,418 Cattle distributed on Grassland Herbaceous and Pasture/Hay Input Fecal Production Rate Cattle 10E10 cfu/animal/day

  31. Feral Hog #s in Leona 21,462 Feral Hogs distributed on 100 meter buffer of stream in non-developed areas Input Fecal Production Rate Feral Hogs 1.1E10 cfu/animal/day

  32. Sheep/Goats #s in Leona Uvalde 8,055 Zavala 1,269 Frio 168 Sheep/Goats distributed on Grassland Herbaceous, Pasture/Hay, Shrubland & Woodland Input Fecal Production Rate Sheep/Goats 1.2E10 cfu/animal/day

  33. Deer #s in Leona 16.8/1,000 acres Deer distributed on Near-Riparian Forest, Shrubland & Woodland Input Fecal Production Rate Deer 3.5E8 cfu/animal/day

  34. Dog #s in Leona 1.6/household Input Fecal Production Rate Dogs 5.0E9 cfu/animal/day Homes in each subbasin based on 2010 Census Block Data

  35. Homes in each subbasin based on 2010 Census Block Data Masks out areas covered by public wastewater service areas Uses NRCS Soils Data to define Septic Drainage Limitation Class Effluent Rate 10E6 cfu/100 mL with discharge of 60 gal/person/day for systems on soils with septic limitations

  36. Sources not included SELECT does not yet handle • Exotics • Small wildlife (birds, raccoons, etc)

  37. SELECT Indicates potential loadings based on a “worst case” scenario Highlight “hot spots” to consider for control efforts These are preliminary results open to stakeholder feedback

  38. Contact Information Nikki Jackson Email: njackson@tiaer.tarleton.edu Office Phone: 254.968.1920 Anne McFarland Email: mcfarla@tiaer.tarleton.edu Office Phone: 254.968.9581

  39. Questions? Thank You Anne McFarland Texas Institute for Applied Environmental Research mcfarla@tiaer.tarleton.edu 254.968.9581

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