1 / 28

Bacteria and Benthic TMDLs for selected Appomattox County Streams

Bacteria and Benthic TMDLs for selected Appomattox County Streams. First Public Meeting June 28, 2012. Overview of Presentation. Overview of TMDL Development Impaired Streams Information Potential Bacteria Sources Basis for Benthic Impairments Next Steps. What is a TMDL?.

clovis
Download Presentation

Bacteria and Benthic TMDLs for selected Appomattox County Streams

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bacteria and Benthic TMDLs for selected Appomattox County Streams First Public Meeting June 28, 2012

  2. Overview of Presentation • Overview of TMDL Development • Impaired Streams Information • Potential Bacteria Sources • Basis for Benthic Impairments • Next Steps

  3. What is a TMDL? Total Maximum Daily Load • The maximum amount of pollutant that can enter a water body without negatively affecting its beneficial uses • fishing, swimming, wildlife habitat, aquatic life, shellfish harvesting • TMDL = point sources + nonpoint sources + margin of safety

  4. TMDL Target Load Load Impaired Watershed Non-Impaired Watershed Reducing load in the impaired watershed to the target TMDL load is expected to restore water quality Example TMDL

  5. Location of Impaired Segments

  6. Bacteria Impairments • in Appomattox County • Stonewall Creek – 9.04miles, impaired from headwaters to James River • Wreck Island Creek – 19.34miles, impaired from headwaters to James River • North Creek – 5.80miles, impaired from headwaters to Wreck Island Creek • Bent Creek – 13.46miles, impaired from headwaters to James River

  7. Basis for Impairment Fecal (E. coli) bacteria • Bacteria present in the intestines of warm blooded animals, e.g. human, livestock, wildlife, and birds • Indicator of the potential presence of pathogens in water bodies. • Any station that exceeds an E. coli concentration of 235 cfu/100mL • (where cfu = colony forming units) in more than 10% of its samples is in violation of bacteria water quality standards.

  8. Bacteria Concentrations: Stonewall Creek Violation Rate: 2-STW001.72: 22%

  9. Bacteria Concentrations: Wreck Island Creek Violation Rates: 2-WIC000.40: 17% 2-WIC012.60: 50%

  10. Bacteria Concentrations: North Creek Violation Rate: 2-NOT001.59: 83%

  11. Bacteria Concentrations: Bent Creek Violation Rate: 2-BUF002.10: 29%

  12. Bacteria Concentrations: James River Violation Rates: 2-JMS229.14: 12%

  13. Bacteria TMDL Development • Watershed and Source Characterization – estimate bacteria loads in the watershed through GIS calculations, personal contacts, and professional opinions • Modeling – determine the contribution of each load to the stream • Allocation – determine how much bacteria from various sources can enter the stream without causing water quality violations

  14. Causes of Impairment • Any source of bacteria to the stream Kyle Hall, 2006

  15. The slides to follow describe the sources of bacteria in the watersheds • Your input on all the populations of sources in these watersheds will help us improve our watershed model How can you help?

  16. Wildlife Livestock Crops Forest Pasture Residential Stream Humans and Pets Sources and Distribution of Bacteria

  17. Die-off Die-off Direct Deposit Die-off Stream Fate and Transport of Bacteria: Livestock Storage Crops Pasture

  18. Fate and Transport of Bacteria: Wildlife Crops Forest Die-off Pasture Residential Direct Deposit Stream

  19. Fate and Transport of Bacteria: Humans and Pets Failing Septic System Die-off Straight Pipe Pets Stream

  20. Benthic TMDL Development Benthic Macroinvertebrates • Stream-inhabiting Organisms • Benthic: Bottom dwelling • Macro: Large enough to see • Invertebrates: Without backbones • Used in biological or bio-monitoring

  21. Stream Condition Index (SCI) Assessment (Bio-monitoring) • Stream sample measurements (metrics) • Number • Diversity • Pollution tolerance • Quantitative • Non-impaired, slight, moderate, severe • Assesses compliance with Aquatic Life Use standard • Impairment: requires two or more assessments of ‘moderate’ or one ‘severe’

  22. Benthic Impairment • in Appomattox County • Phelps Branch – 2.07 miles impaired – from State Route 659 crossing to confluence with North Creek

  23. Basis for ImpairmentPhelps Branch SCI = Stream Condition Index Conditions at Station 2-PLP002.08 show a minor to moderate impairment.

  24. Benthic stressor analysis • Cause of impairment not specified • Identify potential stressors (causes of impairment) • Collect and analyze available data for each potential stressor • Identify most probable stressors as the basis for the TMDL

  25. Conceptual model

  26. Activities that impact the benthic community • Land-disturbing activities • Changing pervious land to impervious land • Stream bank modifications • Excessive or illegal discharges • Addition of toxic substances

  27. Next Steps • Continue to receive input from stakeholders • Bacteria TMDLs • Hydrology and Water Quality calibration • Benthic TMDLs • Finalize selection of TMDL stressors • Calculate TMDL target loads • Create practical final scenarios

  28. Karen KlineSeitz Hall (0303)Virginia TechBlacksburg, VA 24061klinek@vt.edu540-231-0094 ftp://bsesrv214.bse.vt.edu/Kline/JamesRiver/Appomattox Contact Information

More Related