1. Chowan River TMDL Development and Source Assessment Tidewater Area October 20, 2004

2. Watershed

3. TMDL Steps – Tidewater Monitoring/Listing - Identification of Water Quality Problem. Source Assessment – Locating potential contributors of pollutant in watershed. Modeling – Examining the movement of sources from the land to the water. Allocation/TMDL – Use the model to determine the load reductions necessary to achieve water quality goals.

4. Historical Water Quality Data Analysis Fecal Coliform Concentrations ImpairmentStation Sampled Dates Count (#) Minimum (cfu/100ml) Maximum (cfu/100ml) Mean (cfu/100ml) Median (cfu/100ml) Violation (%) 1,000 Violation (%) 400 Milldam Creek5BMLD001.929/95-3/0483498,0004061001117 Nawney Creek5BNWN000.006/93-3/04100254,7005892001734 Nawney Creek5BNWN001.846/93-3/04100252,9005282101838 West Neck Creek5BWNC001.731/85-5/04201924,000506100611 West Neck Creek5BWNc003.656/91-5/04103254,200307100573 West Neck Creek5BWNC006.646/72-5/7970198,0009531052127 West Neck Creek5BWNC010.029/95-3/0486222,0007153503149 London Bridge Creek 7LOB003.7012/97-8/0032951,6001,1671,6005988

5. Water Quality Data Analysis During TMDL Development ImpairmentStation Sampled Dates Count (#) Minimum (cfu/100ml) Maximum (cfu/100ml) Mean (cfu/100ml) Median (cfu/100ml) Violation (%) 235 Milldam Creek5BMLD001.92 7/02- 3/04 10 6201847530 Nawney Creek5BNWN000.00 7/02- 3/04 10 7501596020 Nawney Creek5BNWN001.84 7/02- 3/04 9104201399022 West Neck Creek5BWNC001.73 7/02- 5/04 1210450982517 West Neck Creek5BWNC003.65 7/02- 5/04 91012040200

6. Enterococci Data ImpairmentStation Count (#) Minimum (cfu/100ml) Maximum (cfu/100ml) Mean (cfu/100ml) Median (cfu/100ml) Violation 1 (%) Nawney Creek5BNWN000.0014102,0002785536 West Neck Creek (Upper)5BWNC010.0213102,00037028077 London Bridge Creek 7LOB001.7913402,00042529077 1 Violations based on Enterococci instantaneous standard (i.e., 104 cfu/100 ml)

7. Source Assessment Livestock Wildlife Pets Permitted discharges Wastewater treatment facilities Human Biosolids

8. Permitted Discharges Chlorine  fecal coliform translator Historical averages (DMR) for calibration period Design values for allocations Direct application

9. Permitted Discharges

10. ImpairmentPermit IDTypeFacilityComment West Neck Creek (Upper)VA0005266-001IndustrialUS Naval Air Station Oceana West Neck Creek (Upper)VA0005266-002IndustrialUS Naval Air Station Oceana London Bridge CreekVA0005266-003IndustrialUS Naval Air Station Oceana West Neck Creek (Upper)VA0005266-004IndustrialUS Naval Air Station Oceana London Bridge CreekVA0005266-005IndustrialUS Naval Air Station Oceana London Bridge CreekVA0005266-007IndustrialUS Naval Air Station Oceana West Neck Creek (Upper)VA0005266-NR-012IndustrialUS Naval Air Station OceanaStorm Water Outfall Nawney CreekVPG150001CAFOBarry Knight Hog FarmNow owned by Back Bay NWF West Neck Creek and London Bridge Creek VAR040043MS4 Exact location unknown

11. Human Source Population, housing units, and onsite treatment system based on U.S. Census Sanitary Sewer Loading rates  Exfiltration  Overflows Land-applied / direct deposition  Loading type  Proximity to stream

12. Human Source Septic Systems Failure to soil surface throughout year Lateral movement continuously to stream Straight Pipes Direct continuous input into stream Biosolids Land-applied

13. Human Source

14. Human Source (2004) ImpairmentPopulation Housing Units (HU) HU with Sewer HU with Septic HU with Other Milldam Creek 151571515 Nawney Creek 70326402604 West Neck Creek (Upper) 29,5499,7489,2644795 West Neck Creek (Middle) 4,4311,51753996612 London Bridge Creek 42,58515,35815,282761 TOTAL 77,41926,94425,0861,83227

15. Pet Source Population/household based on literature values, veterinarians, and animal control Translated to housing units based on U.S. Census Land-applied

16. Pet Source (2004) ImpairmentDogsCats Milldam Creek 3034 Nawney Creek 141158 West Neck Creek (Upper) 5,2055,829 West Neck Creek (Middle) 810907 London Bridge Creek 8,2019,184 Total 14,38716,112

17. Livestock Source Distribution of waste Pastured Confined, waste collected, spread Direct deposition to the stream Seasonal varying applications Population Virginia Agricultural Statistics Consultation with SWCD, NRCS, VADCR, and VCE Watershed visits

18. Livestock Population (2002) Impairment All Cattle BeefDairyHogsHorseSheep Milldam Creek 5108262 Nawney Creek 5081026621 West Neck Creek (Upper) 39616120716 West Neck Creek (Middle) 10201534 London Bridge Creek 33515417814 Total 13722312473057

19. Wildlife Source Population Animal densities from VDGIF biologists Habitat from literature values Distribution of waste based on habitat Land-applied Direct deposition to the stream Seasonal variations based on migration patterns and food sources

20. Wildlife Population ImpairmentDeerGooseDuckMuskratRaccoonBeaverSeagull Milldam Creek 3318481571534295 Nawney Creek 63153935428434117 West Neck Creek (Upper) 78236066247852195 West Neck Creek (Middle) 4515404182013998 London Bridge Creek 64164383639360149 Total 283872302,4271,509227654

21. Bacterial Source Tracking Antibiotic Resistance Analysis (ARA) Differentiates the sources of bacteria based on bacterial resistance to antibiotics

22. Bacterial Source Tracking Results WaterbodyStation Human (%) Pet (%) Livestock (%) Wildlife (%) Milldam Creek 5BMLD001.9215213826 Nawney Creek 5BNWN000.0013173832 West Neck Creek 5BWNC010.0210164925

23. Modeling

24. Hydrologic model Runoff model HSPF Water Quality model Tidal/Estuary model CE-QUAL-W2 Model Calibration and Validation Based on data availability, period of interest

25. Modeling

26. Pets Biosolids Application VPDES Permit Conceptual Model Mathematical Representation Withdrawal Direct discharges Overland Wildlife on the Land Pastured Livestock Lateral Flow from Septic Systems Parking Lots Wildlife in Stream Livestock in Stream Septic Failures Sewer Overflows Straight Pipes

27. Hydrologic Modeling Components Climatic data Land use Topography Soils Stream channel characteristics Point source discharge/withdrawal Flow data

28. Land use

29. ImpairmentAcres Forest (%) Barren (%) Agricultural (%) Urban (%) Water (%) Milldam Creek 2,4646028066 Nawney Creek 4,7584067425 West Neck Creek (Upper) 11,10013049136 West Neck Creek (Middle) 7,2216028066 London Bridge Creek 5,851124223924 TOTAL31,394

30. Water Quality Modeling Components Sources Fecal production FC densities FC distribution Delivery Mechanisms Direct Land-applied Temporal Variation

31. Public Meeting 2 (Date?) Public Meeting 3 (Date?) Public Review Submit to EPA State Approval Implementation Plan Development Implementation

33. Hydrologic Calibration