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Home My WebLink AboutJ2-Haw,Deep,etc.TurbidityFecalTMDLTotal Maximum Daily Load for Turbidity and Fecal Coliform for Haw River, Deep River, Third Fork Creek, and Dan River in North Carolina Final Report EPA Approved Date: Jan 11, 2005 Cape Fear River Basin and Roanoke River Basin Prepared by: NC Department of Environment and Natural Resources Division of Water Quality Water Quality Section — Planning Branch, 1617 Mail Service Center Raleigh, NC 27699-1617 r (919) 733-5083 cl� li�'C Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River SUMMARY SHEET Total Maximum Daily Load (TMDL) 1.303(d) Listed Water Body Information State: North Carolina Counties: Alamance, Caswell, Durham, Forsyth, Guilford, Randolph, Rockingham, Stokes, and Surry Major River Basins: Cape Fear River Basin (03030002 & 03030003) and Roanoke River Basin (03010103) Watersheds: Haw River, Deep River, Third Fork Creek, and Dan River Impaired Water Body (2002 303(d) List): Water Body Name - Water Quality AL Subbasin Impairment Length (AU) Classification � 6-digit Code (mi) Haw River—16-(1)d C - Aquatic life and 03-06-02 Turbidity 13 secondary contact recreation Haw River—16-(1)d C - Aquatic life and 03-06-02 Fecal Coliform 13 secondary contact recreation Deep River - 17-(4)b WS-1V — Potable water 03-06-08 Fecal Coliform 6.8 supply Third Fork Creek WS-1V - Potable water 03-06-05 Turbidity 3.6 16-41-1-12-(2) supply Dan River — 22-(31.5) WS-1V - Potable water 03-02-03 Turbidity 14.2 supply Constituent(s) of Concern: Fecal Coliform Bacteria and Turbidity Designated Uses: Biological integrity, water supply, propagation of aquatic life, and recreation. Applicable Water Quality Standards for Class C and Class WS IV Waters: ❑ Turbidity: not to exceed 50 NTU ❑ Fecal coliform shall not exceed a geometric mean of 200/100 mL (membrane filter count) based upon at least five consecutive samples examined during any 30 day period, nor exceed 400/100 mL in more than 20 percent of the samples examined during such period. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 2. TMDL Development Analysis/Modeling: Load duration curves based on cumulative frequency distribution of flow conditions in the watershed. Allowable loads are average loads over the recurrence interval between the 95`h and 101hpercent flow exceeded (excludes extreme drought (>95`hpercentile) and floods (<101h percentile). Percent reductions expressed as the average value between existing loads (typically calculated using an equation to fit a curve through actual water quality violations) and the allowable load at each percent flow exceeded. Critical Conditions: Critical conditions are accounted in the load curve analysis by using an extended period of stream flow and water quality data, and by examining at what flow (percent flow exceeded) the existing load violations occur. Seasonal Variation: Seasonal variation in hydrology, climatic conditions, and watershed activities are represented through the use of a continuous flow gage and the use of all readily available water quality data collected in the watershed. ii Turbidity and Fecal Colifonn TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 3. Allocation Watershed/Stream Reach Pollutants / Watersheds Existing Load WLA' LA MOS 0 TMDL Percent Reduction I. TSS (tons/day) Haw River 183.16 22.31 48.95 Explicit 10 % 71.26 61 Third Fork 1.58 0.36 0.39 Explicit 10 % 0.75 53 Dan River 248.20 1.21 100.53 Explicit 10 % 101.74 59 II. Fecal Coliform (#/day) Haw River 1.44E+13 1.79E+12 1.56E+12 Explicit 10 % 3.35E+12 77 Deep River 2.47E+12 5.87E+11 3.42E+10 Explicit 10 % 6.22E+11 75 Notes: WLA = wasteload allocation, LA = load allocation, MOS = margin of safety. 1. WLA = TMDL — LA - MOS; where TMDL is the average allowable load between the 95th and 1 Oth percent flow exceeded. 2. Margin of safety (MOS) equivalent to 10 percent of the target concentration for fecal coliform and turbidity. 3. Turbidity is not a concentration and, as a measure, cannot be directly converted into loadings required for the TMDL. Total suspended solids (TSS) was therefore selected as the surrogate measure for turbidity and used to develop the TMDL target and limits (USEPA 1999). 4. Public Notice Date: September 16, 2004 5. Submittal Date: November 3, 2004 6. Establishment Date: 7. EPA Lead on TMDL (EPA or blank): No 8. TMDL Considers Point Source, Nonpoint Source, or both: Both iii Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Table of Contents 1. Introduction............................................................................................... 1.1. Watershed Description...................................................................... 1.2. Water Quality Target: North Carolina Water Quality Standard....... 1.2.1. Water Quality Standard for Turbidity ........................................ 1.2.2. Water Quality Standard for Fecal Coliform ............................... 1.3. Water Quality Monitoring................................................................. 1.3.1. Turbidity..................................................................................... 1.3.2. Fecal Coliform............................................................................ 2. General Source Assessment...................................................................... 2.1. General Sources of Turbidity............................................................ 2.1.1. Non -point Sources of Turbidity ................................................. 2.1.2. Point Sources of Turbidity......................................................... 2.2. General Sources of Fecal Coliform................................................... 2.2.1. Non -point Sources of Fecal Coliform........................................ 2.2.2. Point Sources of Fecal Coliform................................................ 3. Haw River Impairment.............................................................................. 3.1. Source Assessment........................................................................ 3.1.1. NPDES Wastewater Permits ...................................................... 3.1.2. NPDES General Permits............................................................ 3.1.3. NPDES Stormwater MS4s......................................................... 3.1.4. Livestock Populations................................................................ 3.1.5. Septic Tanks............................................................................... 3.2. Technical Approach.......................................................................... 3.2.1. Endpoint for Turbidity................................................................ 3.2.2. Endpoint for Fecal Coliform...................................................... 3.2.3. Flow Duration Curve.................................................................. 3.2.4. Load Duration Curve.................................................................. 3.3. Total Maximum Daily Loads (TMDL)............................................. 3.3.1. Margin of Safety (MOS)............................................................. 3.3.2. Target Reduction......................................................................... 3.3.3. TMDL Allocation....................................................................... 3.3.4. Critical Condition and Seasonal Variation ................................. 4. Deep River Impairment............................................................................. 4.1. Source Assessment........................................................................ 4.1.1. NPDES Wastewater Permits ...................................................... 4.1.2. NPDES General Permits............................................................ 4.1.3. NPDES Stormwater MS4s......................................................... 4.1.4. Livestock Populations................................................................ 4.1.5. Septic Tanks............................................................................... 4.2. Technical Approach.......................................................................... 4.2.1. Endpoint for Fecal Coliform...................................................... 4.2.2. Flow Duration Curve.................................................................. 4.2.3. Load Duration Curve.................................................................. 4.3. Total Maximum Daily Loads (TMDL)............................................. 4.3.1. Margin of Safety (MOS)............................................................. 4.3.2. Target Reduction......................................................................... 4.3.3. TMDL Allocation....................................................................... 4.3.4. Critical Condition and Seasonal Variation ................................. 5. Third Fork Creek Impairment................................................................... ................................ 3 ................................ 6 ..............................14 ..............................14 ..............................14 ..............................14 ..............................15 ..............................16 ..............................18 ..............................18 ..............................18 ..............................19 ..............................20 ..............................20 ..............................22 ..............................24 ..............................24 ..............................24 ..............................25 ..............................26 ..............................26 ..............................27 ..............................28 ..............................28 ..............................29 ..............................29 .............................. 30 .............................. 33 ..............................34 ..............................34 .............................. 37 .............................. 39 ..............................40 ..............................40 ..............................40 ..............................40 ..............................40 ..............................41 ..............................41 ..............................42 ..............................42 ..............................43 ..............................44 ..............................45 ..............................45 ..............................45 ..............................47 ..............................48 ..............................49 1 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 5.1. Source Assessment..........................................................................................................................49 5.1.1. NPDES Wastewater Permits....................................................................................................49 5.1.2. NPDES General Permits..........................................................................................................49 5.1.3. NPDES Stormwater MS4s.......................................................................................................49 5.2. Technical Approach........................................................................................................................50 5.2.1. Endpoint for Turbidity..............................................................................................................50 5.2.2. Flow Duration Curve................................................................................................................50 5.2.3. Load Duration Curve................................................................................................................51 5.3. Total Maximum Daily Loads (TMDL)...........................................................................................53 5.3.1. Margin of Safety (MOS)...........................................................................................................53 5.3.2. Target Reduction.......................................................................................................................53 5.3.3. TMDL Allocation.....................................................................................................................55 5.3.4. Critical Condition and Seasonal Variation...............................................................................56 6. Dan River Impairment.............................................................................................................................57 6.1. Source Assessment..........................................................................................................................57 6.1.1. NPDES Wastewater Permits....................................................................................................57 6.1.2. NPDES General Permits..........................................................................................................58 6.1.3. NPDES Stormwater MS4s.......................................................................................................59 6.2. Technical Approach........................................................................................................................59 6.2.1. Endpoint for Turbidity..............................................................................................................59 6.2.2. Flow Duration Curve................................................................................................................59 6.2.3. Load Duration Curve................................................................................................................60 6.3. Total Maximum Daily Loads (TMDL)...........................................................................................62 6.3.1. Margin of Safety (MOS)...........................................................................................................62 6.3.2. Target Reduction.......................................................................................................................62 6.3.3. TMDL Allocation.....................................................................................................................64 7. Summary and Future Consideration........................................................................................................65 7.1 Stream Monitoring............................................................................................................................66 7.2 Implementation Plan.........................................................................................................................66 8. Public Participation.................................................................................................................................67 9. Further Information.................................................................................................................................67 10. References............................................................................................................................................68 11. APPENDICES.......................................................................................................................................70 Appendix 11.1. Water Quality Parameters Used for TMDL Development..........................................70 Appendix 11.2. NPDES Permits............................................................................................................76 Appendix 11.3. Load Reduction Estimations.........................................................................................78 Appendix 11.4. Estimates of Relative Loadings for Point and Non -point Sources...............................82 Appendix 11.5. Public Notice................................................................................................................84 Appendix 11.6. Public Comments and DWQ Response........................................................................89 N Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 1. Introduction This report presents the development of Total Maximum Daily Loads (TMDLs) for four water bodies in North Carolina: Haw River, Deep River, Third Fork Creek, and Dan River. The first three water -bodies are located in the Cape Fear River Basin (CFRB) (Figure 1.1) while the Dan River is located in the Roanoke River Basin (RRB) (Figure 1.2). As identified by the North Carolina Division of Water Quality (DWQ), the impaired segments of the four water bodies are as follows (NCDENR 2003): ❑ The Haw River in the CFRB is impaired due to fecal coliform and turbidity. The impaired segment is located in sub -basin 30602 from NC 87 to NC 49. This section of the river runs approximately 13 miles and is designated as a class C waterl. ❑ The Deep River in the CFRB is impaired due to fecal coliform. The impaired segment is located in sub -basin 30608 from SR 1113 to SR 1921. This section of the stream runs approximately 7 miles and is designated as a class WS-IV waterl. ❑ The Third Fork Creek in the CFRB is impaired due to turbidity. The impaired segment is located in sub -basin 30605 from 2.0 miles upstream of NC Hwy 54 to New Hope Creek. This section of the stream runs approximately 4 miles and is designated as a class WS-IV waterl. ❑ The Dan River in the RRB is impaired due to turbidity. The impaired segment is located in sub -basin 30203 from a point 0.7 mile upstream of Jacobs Creek to a point of 0.8 mile down stream of Matrimony Creek. This section of the stream runs approximately 14 miles and is designated as a class WS-IV waterl. Section 303(d) of the Clean Water Act (CWA) requires States to develop a list of water bodies that do not meet water quality standards or have impaired uses. The list, referred to as the 303(d) list, is submitted biennially to the U.S. Environment Protection Agency (USEPA) for review. The 303(d) process requires that a Total Maximum Daily Load (TMDL) be developed for each of the waters appearing on Category 5 of the 303(d) list. ' Class C waters are protected for secondary recreation, fishing, wildlife, fish and aquatic life propagation and survival, agriculture and other uses suitable for class C. There are no restrictions on watershed development or types of discharges. 2 Class WS-IV waters are used as sources of potable water supply where WS-1, WS-II or WS-III classification is not feasible. WS-IV waters are generally in moderately to highly developed watersheds or Protected Areas, and involve no categorical restrictions on discharges. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 30 wa.K.W M17- oa ..rr*.All • XLI]Y LI KIR� • 11 ti. a'� k•3a�..W Ihlri"Ok Cr*A Y 7PI�4 41}f U A ER4 F:�[O 'ihriC 4?7 . N Gi430C170 a KPOO P:IS 42 r7RJN] ' aye, 22+] 1000G SJ I�Yf71 lit ' latilXJt �y�ppp W 0o wife W E Figure 1.1. Upper Cape Fear River Basin showing Haw River, Deep River, and Third Fork Creek and water quality stations along the main water bodies. El Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 2D 20 N W - E 5 #D I11110a Figure 1.2. Roanoke River Basin showing the Dan River and water quality stations along the main water body. 5 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River The objective of a TMDL is to allocate allowable pollutant loads to known sources so that actions may be taken to restore the water to its intended uses (USEPA, 1991). Generally, the primary components of a TMDL, as identified by USEPA (1991, 2000a) and the Federal Advisory Committee (FACA) (USEPA, 1998) are as follows: Target identification or selection of pollutant(s) and end-point(s) for consideration. The pollutant and end -point are generally associated with measurable water quality related characteristics that indicate compliance with water quality standards. North Carolina indicates known pollutants on the 303(d) list. Source assessment. All sources that contribute to the impairment should be identified and loads quantified, where sufficient data exist. Assimilative capacity estimation or level of pollutant reduction needed to achieve water quality goal. The level of pollution should be characterized for the water body, highlighting how current conditions deviate from the target end -point. Generally, this component is identified through water quality modeling. Allocation of pollutant loads. Allocating pollutant control responsibility to the sources of impairment. The waste load allocation portion of the TMDL accounts for the loads associated with existing and future point sources. Similarly, the load allocation portion of the TMDL accounts for the loads associated with existing and future non -point sources, storm water, and natural background. Margin of Safety. The margin of safety addresses uncertainties associated with pollutant loads, modeling techniques, and data collection. Per EPA (2000a), the margin of safety may be expressed explicitly as unallocated assimilative capacity or implicitly due to conservative assumptions. Seasonal variation. The TMDL should consider seasonal variation in the pollutant loads and end -point. Variability can arise due to stream flows, temperatures, and exceptional events (e.g., droughts, hurricanes). Section 303(d) of the CWA and the Water Quality Planning and Management regulation (USEPA, 2000a) requires EPA to review all TMDLs for approval. Once EPA approves a TMDL, then the water body may be moved to Category 4a of the 303(d) list. Water bodies remain on Category 4a of the list until compliance with water quality standards is achieved. Where conditions are not appropriate for the development of a TMDL, management strategies may be implemented in an effort to restore water quality. 1.1. Watershed Description Watershed areas that contributed turbidity and fecal coliform in the polluted section of the water bodies are manually delineated using the delineation tools provided in version 3.0 of the Better Con Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Assessment Science Integrating Point and Non -point Sources (BASINS) system. The delineation of the watersheds was done to understand land use compositions in each watershed. The land use compositions were estimated using the BASINS default land use data, which was based on the USGS Geographic Information Retrieval and Analysis System (GIRAS). The GIRAS was developed on mid 70s; therefore, the land use compositions do not reveal the current land use status. However, it provides a comprehensible understanding of the distribution pattern of the land uses in the watersheds. The delineated watersheds and their land use distributions are shown in Figures 1.3 through 1.6. Statistics of the land use coverage are presented in Table 1.1. Table 1.1. Land use acreages and their percent compositions in the four watersheds. Land Use Haw River Deep River Third Fork Creek Dan River Area (sq.mi) Area (%) Area (sq.mi) Area (%) Area (sq.mi) Area (%) Area (sq.mi) Area (%) Urban 112.00 18.49 36.93 29.54 9.75 59.16 33.97 2.98 Agriculture 280.40 46.27 33.68 26.94 X X 327.64 28.74 Forest 200.10 33.02 51.31 41.05 6.25 37.93 769.39 67.49 Water/Wetland 12.18 2.01 1.93 1.54 0.03 0.21 7.30 0.64 Barren 1.15 0.19 1.18 0.94 0.44 2.69 1.60 0.14 Total 606.00 100 125.01 100 16.48 100 1,139.89 100 The Haw River, Deep River, and Third Fork Creek watersheds are spread the upper piedmont of North Carolina. The Dan River watershed is alternately flows between Virginia and North Carolina. The impaired segment of the river is located in North Carolina (Figure 1.6). 7 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River R OCKINONKM �-@"ELL e Or FBRdr Ti i putim lu 0 10 20 bgld§m - HAW Myer Land Use Class Agncuttural Land Muren Land Forest Land N 0 Unknown Oman or 9ul I[.up Land Water - Wetlands W E * Outlet Subbasms County 04undaries Figure 1.3. Mid 70's land use distribution in the Haw River watershed N. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Ffl RSY iN 10 jrjugbtl 6 a 6 12 1414S f I Deed} RIvaf Land Use Class Agricultural Land Dar reii Land For-est Land - Urban or Built-up Land Water Out I et Subb asin s County Soun dafi$ $ Figure 1.4. Mid 70's land use distribution in the Deep River watershed. 6 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River pyrlpx l Third Fork Creek Land U s-e Class WBarren Lard Forest Land N LJ roan or B uilt-W R Land water A 0 Utlet W E F-I Su bbaslns County Boundaries S Figure 1.5. Mid 70's land use distribution in the Third Fork Creek watershed. 10 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 4 Kibl s1 4 2U Outlet Dan River Land Use Class 0 Agricultural Land - Barren Land Forest Land Urban or Sul It -up Land - Water County Boundarle s Z�G"o at«WOMkm Figure 1.6. Mid 70's land use distribution in the Dan River watershed. 40 M41e1 11 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Dominating characteristics of land uses in the four watersheds vary. Agricultural and forested lands dominated the land uses in the Haw River watershed. Forested lands dominated the land uses in the Deep River and Dan River watersheds, whereas urban land dominated the land uses in Third Fork Creek watershed. In recent years, significant developments have occurred and resulted in conversion of large rural parcels into residential and commercial areas in the watersheds. According to the U.S. Census, 1990 and 2000, population increased by 21 percent in Guildford and Alamance Counties. Likewise seven percent was encountered in Rockingham County. These three counties encompass the Haw River, Deep River, and Dan River watersheds. Similarly, population in Durham and Stokes Counties increased by 23 percent and 20 percent respectively. These two counties encompass the polluted section of the Third Fork Creek and Dan River watersheds respectively. The Dan River watershed also spreads through Patrick County and Henry County in Virginia. Population increments in the two counties were only 11 percent and 1 percent respectively, which is indeed comparatively insignificant. Conversion of rural areas to urban land uses can significantly enhance soil erosion. Higher imperviousness of the new land use increases urban runoff volume and therefore, results in erosion of surface soils and stream channels. The DWQ conducted a special study in the Haw River watershed to understand the magnitude of sediment loading due to urbanization. The DWQ collected water samples at the ambient station, B1140000, in the watershed for a six -week period from 01/06/04 through 02/16/04. The station is located approximately 0.15 miles downstream from Hwy 49, at USGS station # 02096500, and receives runoff from both agricultural and urban lands. The major urban areas are Greensboro and Burlington. Two major storm events occurred during the special study period (Figure 1.7). The first storm event occurred during the early morning of 2/3/04. The storm increased the flow from 381 cfs to 3170 cfs in the Haw River at B 1140000. The storm event occurred very rapidly over a period of approximately six hours with a precipitation total of 0.61 inches. In addition, runoff in the drainage area was enhanced due to ground saturation from the previous week ice storm. The 12 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River storm event carried substantial amount of sediment and solid materials from urban as well as agricultural lands, and the turbidity level increased from 7.6 NTU to 102 NTU (Figure 1.7). 5000 200.0 4500 180.0 4000 160.0 3500 140.0 3000 ■ 120.0 ? 2500 100.0 3 2000 ■ 80.0 LL 1500 60.0 ■ ■ 1000 40.0 500 20.0 Flow ■ Turbidity 0 0.0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 N o 00 o r � NT 00 (0 1* 00 (0 q* N o r N o r N 00 (D qI 00 q* N o � N o � N (D qI N o r N 2/3/04 2/4/04 2/5/04 2/6/04 2/7/04 2/8/04 Sampling Time (hrs) and Date Figure 1.7. Association between turbidity and flow in the Haw River at ambient station B 1140000. The second storm event occurred on 02/06/04 and continued to 02/07/04 with 0.52 inches of precipitation. The saturated ground conditions from the previous storm events further enhanced the runoff throughout the watershed. Flow at the ambient station, B 1140000, increased from 748 cfs to 4,390 cfs, and turbidity levels increased from 24 NTU to 175 NTU. During the six weeks period, a significant relationship between turbidity and flow was observed in the Haw River, where urban lands are rapidly expanding. The relationship is given in Equation 1.1 below. In the Haw River, turbidity increased by 0.03 NTU for every flow increase and remained constant at 5.67 NTU on an average during no flow period. Turbidity = 5.67 + 0.03 * Flow R-Square = 0.66---------------------------- (1.1) The conversion of rural land uses will shift the non -point source contribution of fecal coliform from agriculture activities such as cattle grazing and manure application to urban sources such as fecal waste from waste household pets, sanitary sewer overflows (SSOs) and leaking sewer lines. 13 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Generally, fecal coliform contribution from SSOs and leaking sewer lines will be more obvious during typical and low periods. In a study conducted by the Piedmont Triad Council of Governments (PTCOG) in the East Fork Deep watershed (an upper part of the Deep River watershed), occasional exceedances of fecal coliform due to SSOs, leaking sewer lines, and direct pipelines are predicted (NCDENR, 2004). 1.2. Water Quality Target: North Carolina Water Quality Standard. 1.2.1. Water Quality Standard for Turbidity The North Carolina fresh water quality standard for Class WS-IV and C waters for turbidity (T15A: 0213.0211) states: The turbidity in the receiving water shall not exceed 50 Nephelometric Turbidity Units (NTU) in streams not designated as trout waters and 10 NTU in stream, lakes or reservoirs designated as trout water; for lakes and reservoirs not designated as trout waters, the turbidity shall not exceed 25 NTU; if turbidity exceeds these levels due to natural background conditions, the existing turbidity level cannot be increased. Compliance with this turbidity standard can be met when land management activities employ Best Management Practices (BMPs) recommended by the Designated Nonpoint Source Agency. BMPs must be in full compliance with all specifications governing the proper design, installation, operation and maintenance of such BMPs. 1.2.2. Water Quality Standard for Fecal Coliform The North Carolina fresh water quality standard for Class WS-IV and C waters for fecal coliform (T15A: 0213.0211) states: Organisms of the coliform group: Fecal coliforms shall not exceed a geometric mean of 2001100mL (MF count) based upon at least five consecutive samples examined during any 30-day period, nor exceed 4001100mL in more than 20 percent of the samples examined during such period; violations of the fecal coliform standard are expected during rainfall events and, in some cases, this violation is expected to be caused by uncontrollable nonpoint source pollution; all coliform concentrations are to be analyzed using the membrane filter technique unless high turbidity or other adverse conditions necessitate the tube dilution method; in case of controversy over results, the MPN 5-tube dilution technique will be used as the reference method. 1.3. Water Quality Monitoring The DWQ monitored water quality parameters which include fecal coliform, total suspended solids (TSS), and turbidity, in the three water bodies: Haw River, Deep River, and Dan River. The ambient stations — B 1140000 near NC Hwy 49, B4615000 near Randleman, and N2300000 near Wentworth — were responsible for the 303(d) listing of a portion of the three water bodies 14 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River respectively (Figures 1.1 and 1.2). The DWQ monitored the three ambient stations regularly from January 1997 through March 2004 (Appendix 11.1). The water samples were collected monthly for water quality assessment. A summary of the fecal coliform and turbidity data collected is presented in Table 1.2. The Upper Cape Fear River Basin Association (UCFRBA) monitored the Third Fork Creek at the coalition station B3025000 at Hwy 54 (Figure 1.1). The association collected water samples monthly for the period from April 26, 2002 through September 25, 2003 to examine water quality parameters, which include fecal coliform, TSS, and turbidity. A summary of the fecal coliform and turbidity data collected in the coalition stations is also presented in Table 1.2. Table 1.2: Summary of water quality monitoring for turbidity and fecal coliform impairment. Water Bodies/ Parameters Sampling periods Number of samples collected Number greater than standard Exceeding percentage Responsible organization 1. Haw River Fecal Coliform 1/97 9/03 80 21 a 26 DWQ Fecal coliform 5/02 — 7/02 12 0 b 0 DWQ Turbidity 1/97 — 9/03 73 8 c 11 DWQ 2. Deep River Fecal Coliform 1/97 9/03 72 17 a 24 DWQ 3. Third Fork Creek Turbidity 4/00 — 9/03 42 5 12 UCFRBA 4. Dan River Turbidiy 2/97 — 3/04 78 12 15 DWQ a Instataneous fecal coliform measurement > 400 counts/100ml. b 30-day Geometric mean of fecal coliform measurements > 200 counts/100ml. Turbidity measurements > 50 NTU. 1.3.1. Turbidity The instantaneous data suggest that the turbidity level exceeded 50 NTU in more than 10% during the study period at the sites, B 1140000, B3025000, and N2300000, in the Haw River, 15 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Third Fork Creek, and Dan River respectively (Table 1.2). It appears that there were occasional excursions of turbidity above the water quality standards. 1.3.2. Fecal Coliform The DWQ launched an additional intensive fecal coliform monitoring program in the Haw River from May 21, 2002 through July 9, 2002 to assess the impairment status with regards to the standards specification requiring five samples per 30-day period. A total of 12 samples were collected during the period (Table 1.2). The data was utilized to estimate the 30-day geometric mean to examine whether fecal coliform exceeded the water quality standard, 200 counts /100 mL, at the ambient station, B 1140000. None of the geometric means of fecal coliform exceeded the water quality standard (Figure 1.8). Figure 1.8. Rolling 30-day geometric mean of observed fecal coliform concentration in the Haw River at station B 1140000. Although the geometric mean of fecal coliform did not exceed 200 counts / 100m1 at the ambient sites, B 1140000, in the Haw River, the instantaneous data did, however, suggest that the fecal 16 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River colifrom concentration exceeded 400 counts / 100ml in more than 20 % of the samples examined during January 1997 through September 2003 (Table 1.2). Similar to the Haw River, the fecal coliform concentration also exceeded 400 counts / 100ml in more than 20 % of the samples examined at B4615000 in the Deep River. However, an additional intensive fecal coliform monitoring program with regards to the standards specification requiring five samples per 30-day period was not launched in the Deep River due to limitation in time. Therefore, evaluation of fecal coliform contamination in terms of geometric mean was not conducted for the Deep River. 17 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 2. General Source Assessment Generally, sources of fecal coliform and turbidity may be point or non -point in nature. Point sources are typically those regulated under the National Pollution Discharge Elimination System (NPDES) program. Non -point sources are diffuse sources that typically cannot be identified as entering a water body at a single location. Following sections describe point and non -point sources of turbidity and fecal coliform. 2.1. General Sources of Turbidity Turbidity is a measure of the cloudiness of water. In a water body, the cloudiness can be enhanced due to silt and clay from watershed and stream erosion, organic detritus from streams and wastewater, and phytoplankton growth. In this study, turbidity is measured in the Nephelometric Turbidity Unit (NTU) and is significantly correlated with total suspended solid (TSS). The relationship between Turbidity and TSS is discussed below. 2.1.1. Non -point Sources of Turbidity Potential sources of turbidity from non -point sources are forests, agricultural lands, construction sites, urban runoff, and stream channel erosion. Surface runoff is the main carrier of sediments from forests, agricultural land, and construction sites. Normally, runoff flowing through natural stands, where there are not any land disturbing operations being conducted, carries insignificant amount of sediments. However, when runoff passes through logging and harvesting sites, plantation sites, and site preparation sites, the runoff would carry significant amount of sediment, thereby increasing turbidity in a stream. Similarly, runoff flowing through agricultural land can carry substantial amount of sediments. The amount of sediment depends on erodability of soils, types of agricultural practices, crop type and density, rainfall intensity, and existence and type of agricultural BMPs. Moreover, the amount of sediment load in runoff flowing through constructed site would be substantially higher than in runoff flowing through forests and agricultural land when erosion controls are not properly maintained or required. At a construction site, vegetation cover is lost and soil surface is often disturbed. As a result, the site becomes more exposed to rainfall, and thus increases the probability of rill and gully erosion to occur. The DWQ staff noticed several developing activities such as land clearing and site preparation for residential buildings, IV. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River commercial areas, roads, and highways being conducted in the Haw River and Third Fork Creek watersheds. Urbanization also increases the amount of sediment transported to receiving waters. Impervious urban landscapes like roads, bridges, parking lots, and buildings prevent rainwater to quickly percolate into ground. In the impervious lands, rainwater remains above the surface, gathers sediments and solid materials, and runs off in large amounts. In addition, municipalities install storm sewer systems that quickly channel the urban runoff from roads and other impervious surfaces. Urban runoff increases its velocity once it enters the storm sewer system. When it leaves the system and empties into a stream, large volumes of quickly flowing runoff erode stream banks, damage streamside vegetation, and widen stream channels. 2.1.2. Point Sources of Turbidity Point sources are distinguished from nonpoint sources in that they discharge directly into streams at a discrete point. Point sources of turbidity consist primarily of large and small industries, wastewater -treatment plants, and Municipal Separate Storm Sewer System (MS4). As authorized by the Clean Water Act, the DWQ regulates the National Pollutant Discharge Elimination System (NPDES) permit program to control water pollution due to point sources. Individual homes that are connected to a municipal system, use a septic system, or do not have a surface discharge do not need an NPDES permit; however, industrial, municipal, and other facilities must obtain permits if their discharges go directly to surface waters. 2.1.2.1. NPDES-Regulated Municipal and Industrial Wastewater Treatment Facilities Discharges from wastewater treatment facilities may contribute sediment to receiving waters as total suspended solids (TSS) and/or turbidity. Municipal treatment plants and industrial treatment plants are required to meet surface water quality criteria for turbidity in their effluent. When effluent turbidity concentrations exceed surface water quality criteria, and result in permit violations, action will be taken through the NPDES unit of North Carolina's Division of Water Quality. 19 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 2.1.2.2. NPDES General Permits General permitted facilities, while not subject to effluent TSS, or turbidity limitations, are required to develop a storm water pollution prevention plan, and conduct qualitative and/or quantitative measurements at each storm water discharge outfall and vehicle maintenance area. Sampling methodology and constituents to be measured are characteristic of the volume and nature of the permitted discharge. For example, general permits for mining operations require the permitee to measure settleable solids, total suspended solids, turbidity, rainfall, event duration, and flow in storm water discharge areas. Measurements of pH, oil and grease, total suspended solids, rainfall, and flow are required in on -site vehicle maintenance areas. Similarly, monitoring is required in mine dewatering areas, wastewater associated with sand/gravel mining, and in overflow from other process recycle wastewater systems. 2.1.2.3. Municipal Separate Storm Sewer System (MS4) A recent EPA mandate (Wayland, 2002) requires NPDES permitted storm water to be placed in the waste load allocation (WLA), which was previously reserved for continuous point source waste loads. In 1990, EPA promulgated rules establishing Phase I of the NPDES storm water program. The Phase I program for Municipal Separate Storm Sewer System (MS4) requires operators of medium and large MS4s, which generally serve populations of 100,000 or greater, to implement a storm water management program as a means to control polluted discharges from these MS4s. 2.2. General Sources of Fecal Coliform Both point sources and non -point sources may contribute fecal coliform to the water bodies. Potential sources of fecal coliform loading are discussed below. 2.2.1. Non -point Sources of Fecal Coliform Fecal coliform from non -point sources include those sources that cannot be identified as entering the water body at a specific location. Non -point source pollution can include both urban and agricultural sources, and human and non -human sources (Table 2.1). The non -point sources of fecal coliform in the water bodies include wildlife, livestock (land application of agricultural manure and grazing), urban development (stormwater runoff, including sources from domestic 20 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River animals), failing septic systems, and sewer line systems (illicit connections, leaky sewer lines and sewer system overflows). Table 2.1. Potential Source of Fecal Coliform Bacteria in Urban and Rural Watersheds. (Source: Center for Watershed Protection, 1999) Source Origin Human Sources Sewered watershed Source Combined sewer overflows Sanitary sewer overflows Illegal sanitary connections to storm drains Illegal disposal to storm drains Non-sewered watershed Failing septic systems Poorly operated package plant Landfills Marinas Non -human Sources Domestic animals and urban wildlife Dogs, cats Rats, raccoons Pigeons, gulls, ducks, geese Livestock and rural wildlife Cattle, horse, poultry Beaver, muskrats, deer, waterfowl Hobby farms 2.2.1.1. Land Use Contribution Agricultural land alongside a stream would contribute fecal coliform from livestock and manure applications. In addition, when cattle have direct access to streams, feces may be deposited directly into a stream. Runoff from urban surface is also a potentially significant source of fecal coliform loadings. Urban lands may contribute fecal coliform from pets such as dog and cats. In a study conducted by Hyer et al., 2001, the bacterial loads due to dog waste accounted for nearly 10 percent of the total bacterial load in three creeks of Virginia: Accotink Creek, Blacks Run, and Christians Creek. Furthermore, wildlife faces in runoff may be a frequent source of fecal coliform loading where forest dominates the streamside. 21 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 2.2.1.2. Urban Development/Sanitary Sewer Overflows/WWTP Residual Land Application Fecal coliform can originate from various urban sources. These sources include pet waste, runoff through stormwater, sewers, illicit discharges/connections of sanitary waste, leaky sewer systems, and sewer system overflows. Fecal coliform contamination can be profound when sewer pipes are clogged or flooded by stormwater. Infiltration of rainfall can enter the sewer system through cracks and leaks in pipes. This additional flow volume, in combination with the existing sewer flow, can exceed the capacity of the system resulting in a sanitary -sewer -overflow (SSO). 2.2.2. Point Sources of Fecal Coliform Point sources of fecal coliform consist primarily of large and small industries, wastewater - treatment plants, and Municipal Separate Storm Sewer System (MS4). As authorized by the Clean Water Act, the DWQ regulates the National Pollutant Discharge Elimination System (NPDES) permit program to control water pollution due to point sources. Individual homes that are connected to a municipal system, use a septic system, or do not have a surface discharge do not need an NPDES permit; however, industrial, municipal, and other facilities must obtain permits if their discharges go directly to surface waters. 2.2.2.1. NPDES-Regulated Municipal and Industrial Wastewater Treatment Facilities Discharges from wastewater treatment facilities may contribute fecal coliform to receiving waters. Municipal treatment plants and industrial treatment plants are required to meet surface water quality criteria for fecal coliform in their effluent. When effluent turbidity concentrations exceed surface water quality criteria, and result in permit violations, action will be taken through the NPDES unit of North Carolina's Division of Water Quality. 2.2.2.2. NPDES General Permits General permitted facilities are required to develop a pollution prevention plan to discharge domestic wastewaters from single family residences and other domestic discharges. The permitted flow of these facilities may not in any case exceed 1000 gallon per day. The facilities require to measure BOD5, total suspended residue, fecal coliform, and total residual chlorine. 22 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River The facilities must monitor the pollutants every year and document the following maintenance activities: ❑ Septic tanks shall be maintained at all times to prevent seepage of sewage to the ground. ❑ Septic tanks will be checked at least yearly to determine if solids must be removed or if other maintenance is necessary. ❑ Septic tanks shall be pumped out within three to five years of the issuance date on the Certificate of coverage. ❑ Contents removed from septic tanks shall be disposed at a location and in a manner compliant with all local and state regulations. ❑ Surface sand filters, disinfection apparatus and (if applicable) dechlorination apparatus shall be inspected weekly to confirm proper operation. 23 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 3. Haw River Impairment 3.1. Source Assessment 3.1.1. NPDES Wastewater Permits There were 24 facilities that discharged wastewater continuously to the polluted portion of the Haw River and tributaries under the NPDES program (Table 3.1). Nine out of 24 facilities discharged wastewaters directly to the Haw River (Appendix 11.2). In general, privately own facilities were permitted to discharge daily up to 45 mg/L of TSS and 400 counts/100mL of fecal coliform, whereas publicly own facilities were permitted to discharge weekly average up to 45 mg/L of TSS and 400 counts/ 100mL of fecal coliform to the Haw River. Table 3.1. NPDES Wastewater Permits in the Haw River Permit No. Facility Name Permitted Flow (MGD) TSS (m L) Fecal Coliform (#/100mL) Daily Permitted Limits NC0046809 Pentecostal Holiness Church 0.02 45 400 NC0066966 Quarterstone Farm WWTP 0.16 45 400 NC0001384 Williamsburg plant 0.025 45 400 NC0045144 Western Alamance High School 0.01 45 400 NC0031607 Western Alamance Middle School 0.015 45 400 NC0046043 Oak Ridge Military Academy 0.04 45 400 NC0045161 Altamahaw/Ossipee Elementary School 0.012 45 400 NC0046019 The Summit WWTP 0.015 45 400 NC0066010 Williamsburg Elementary School 0.004 45 400 NC0003913 Altamahaw Division plant 0.15 108 lb 400 NC0065412 Pleasant Ridge WWTP 0.0235 45 400 NC0060259 Willow Oak Mobile Home Park 0.0175 135 400 NC0084778 Harvin Reaction Technology 0.11 45 400 NC0029726 Guilford Correctional Center WWTP 0.025 45 400 NC0038156 Northeast Middle & Senior High WWTP 0.032 45 400 NC0022691 Autumn Forest Manu£ Home Community 0.082 45 400 NC0001210 Monarch Hosiery Mills Incorporated 0.05 81.5 Ib NA NC0038172 McLeansville Middle School WWTP 0.0113 45 400 NC0055271 Shields Mobile Home Park 0.006 45 400 NC0073571 Countryside Manor WWTP 0.015 45 400 Weekly Average Permitted Limit NC0023868 Eastside WWTP 12 45 400 GM NC0024881 Reidsville WWTP 7.5 45 400 GM NC0024325 North Buffalo Creek WWTP 16 45 400 GM NC0047384 T.Z. Osborne WWTP 40 45 400 GM GM = Geometric Mean 24 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 3.1.2. NPDES General Permits All construction activities in the Haw River watershed that disturb one or more acres of land are subject to NC general permit NCGO10000 and as such are required to not cause or contribute to violations of Water Quality Standards. As stated in Permit NCGO10000, page 2, "The discharges allowed by this General Permit shall not cause or contribute to violations of Water Quality Standards. Discharges allowed by this permit must meet applicable wetland standards as outlined in 15A NCAC 2B .0230 and .0231 and water quality certification requirements as outlined in 15A NCAC 2H .0500". Monitoring requirements for these construction activities are outlined in Section B (page 5) of NCGO 10000. As stated, "All erosion and sedimentation control facilities shall be inspected by or under the direction of the permittee at least once every seven calendar days (at least twice every seven days for those facilities discharging to waters of the State listed on the latest EPA approved 303(d) list for construction related indicators of impairment such as turbidity or sedimentation) and within 24 hours after any storm event of greater that 0.5 inches of rain per 24 hour period.." (NCGO10000, Section B) As per 40 CFR § 122.44(d)(1)(vii)(B), where a TMDL has been approved, NPDES permits must contain effluent limits and conditions consistent with the requirements and assumptions of the WLA in the TMDL. While effluent limitations are generally expressed numerically, EPA guidance on NPDES-regulated municipal and small construction storm water discharges is that these effluent limits be expressed as best management practices (BMPs) or other similar requirements, rather than numeric effluent limits (EPA TMDL and WLA Guidance Memo, 2002). Compliance with the turbidity standard in the Haw River is expected to be met when construction and other land management activities in the Haw River watershed employ adequate BMPs. Upon approval of this TMDL, DWQ will notify the NC Division of Land Resources (DLR) and other relevant agencies, including county and local offices in the Haw River watershed responsible in overseeing construction activities, as to the impaired status of the Haw River and the need for a high degree of review in the construction permit review process. Similarly, all single family residences or domestic treatment facilities who discharge wastewaters not exceeding 1000 gallons per day in the Haw River watershed are subject to NC general permit NCG550000 and as such are required to not cause or contribute to violations of Water Quality 25 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Standards. Monitoring requirements for these facilities are outlined in Part I (page 2) of NCG550000 (htip://h2o.enr.state.nc.us/NPDES/documents/NCG55_Permit 2002.1)df). A brief statement of maintenance activities is presented in Section 2.2.2.2. 3.1.3. NPDES Stormwater MS4s Within the Haw River watershed, there is one community that obtained an NPDES stormwater permit under the first phase of federal stormwater regulations, the City of Greensboro. The permit number for the City of Greensboro is NCS000248. The cities of Burlington, Elon College, Gibsonville, Graham, Greenville, and Haw River are identified under the second phase of federal stormwater regulations. The City of Reidsville is identified as a possible candidate for the second phase of federal stormwater regulations. The DWQ has not issued NPDES permit numbers to the cities (from personal communication with DWQ staff, Ms. Aisha Lau). The ArcView software was utilized to overlay the shape files of NC municipalities over the USGS land use coverage (discussed in Section 1.1) in order to estimate the land coverage of the cities under MS4 program. Approximately all urban lands in the Haw River watershed were occupied by the cities. 3.1.4. Livestock Populations The North Carolina Department of Agriculture (NCDA) regularly performs an agricultural census for each county of the state. This census includes estimated livestock populations in each county, as shown in Table 3.2 for the Haw River watershed. The NCDA also ranks each county according to the number of animals in each particular category. Guildford County had the 7th highest population of milk cows in 2003 and Alamance County had the 1 lth highest population of chickens in North Carolina in 2002. With respect to other animals, none of these counties ranks in the top fifteen in terms of population. 26 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Table 3.2. Estimated Livestock population in the Haw River watershed above NC 49 (NCDA). Livestock= . Counties E ff7 � Alamance Guilford Forsyth Rockingham Caswell Swine (2002) 1.2 8.6 <1 7.6 1.3 Cattle (2003) 19.2 16 7.2 10.9 11.1 Beef Cow (2003) 7.9 7.0 3.8 4.7 4.6 Milk Cow (2003) 1.7 2.0 <0.2 0.7 <0.2 Broiler (2002) 3,300 500 <500 <500 <500 Turkey (2002) <500 <500 <500 <500 <500 Chickens (2002) 450 100 <50 <50 <50 (Source: http://www.ncagr.com/stats/cntysumm/) Year of the census is reported for each type of livestock. Counts are reported in thousands. 3.1.5. Septic Tanks The upper Haw River watershed is a rapidly urbanizing area. Thus, most households have connected to water and sewer services provided by municipalities. However, there are still households that do utilize septic systems, as shown in Table 3.3. Table 3.3. Estimated housing units using septic systems in the Haw River watershed in 2002. County Number of Housing Units Number of Septic Systems Percentage of Housing Units with Septic Systems (Alamance 57,578 550[ 0.96 Guilford 189,272 687 0.36 (Forsyth 1 138,573 4361 0.311 Rockingham 41,129 540 1.31 Caswell 9,899 226I 2.28I Source for housing unit: http://www.deh. enr. state.nc.us/oww/Program_improvement_team/Pit_Index.htm Source for septic system: http://quickfacts.census.gov/qfd/states In the City of Greensboro, residents are required to switch from septic to sewer systems within 5 years of the sewer line extension. Recently, Greensboro sewer lines were extended throughout a large portion of the watershed area. 27 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 3.2. Technical Approach Based on the above initial data analysis, it appears that both point sources and non -point sources contributed fecal coliform and turbidity in the Haw River. Because the magnitude of fecal coliform and turbidity in a water body associates with flow condition, a load duration approach is adopted for this study. This approach determines impairment loads under different flow conditions — high flow, transition flow, typical flow, and low flow — to identify source types, specify assimilative capacity of a stream, and to estimate magnitude of load reduction required to meet the water quality standard. The methodology used to develop a load duration curve is based on Cleland (2002). 3.2.1. Endpoint for Turbidity As discussed in Section 2.1, turbidity is a measure of cloudiness and is reported in Nephelometric Turbidity Units (NTU). Therefore, turbidity is not measured in terms of concentrations and cannot be directly converted into loadings required for developing a load duration curve. For this reason, total suspended solid (TSS) was selected as a surrogate measure for this study. In order to observe relationship between TSS and turbidity in the Haw River, a regression equation between the two parameters was developed using the observed data collected from January 1997 through September 2003 in the ambient station, B 1140000, near Haw River. The relationship is shown in Equation 3.1. The coefficient of determination (R-Square) between the two parameters was 0.57; therefore, a moderate relationship between the two parameters was experienced. Y = 3.9327e 0.0432 x R-Square = 0.57----------------------(3.1) Where, Y = TSS in mg/1 and X = turbidity in NTU. Equation 3.1 suggests that the Haw River yielded approximately 3.93 mg/L of TSS during natural condition (NTU = 0). The river, however, increased exponentially TSS by 0.043 mg/L for each turbidity increase. Therefore, the corresponding TSS value at the turbidity standard of 50 NTU was 34 mg/L. M. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 3.2.2. Endpoint for Fecal Coliform The TMDL objectives require the instream fecal coliform concentrations to meet both the instantaneous standard of 400 counts /100mL and the geometric mean standard of 200 counts / 100mL. As discussed in Section 1.3.2, the Haw River does not seem to be contaminated due to fecal coliform when the river is evaluated with regards to the geometric mean standard. Therefore, only the instantaneous standard is considered to be the endpoints for the determination of the fecal colifrom TMDL for the river. 3.2.3. Flow Duration Curve Development of flow duration curve is the first step of load duration approach. A flow duration curve employs a cumulative frequency distribution of measured daily stream flow over the period of record. The curve relates flow values measured at the monitoring station to the percent of time the flow values were equaled or exceeded. Flows are ranked from lowest, which exceed nearly 100 percent of the time, to highest, which exceed less than 1 percent of the time. Reliability of the flow duration curve depends on the period of record available at monitoring stations. Predictability of the curve increases when longer periods of record are used. For that reason, daily stream data collected from January 1928 through September 2003 at the USGS gage station, 02096500, near Haw River, was utilized to develop flow duration curves. The flow duration curve is shown in Figure 3.1. Flow statistics as generated by the curves are presented in Table 3.4. Table 3.4: Flow Statistics for the four water bodies. High Flow Transitional Flow Typical Flow Low Flow (< 1 Oth percentile) (Between 10`h and 301h (Between 301h and 901h (> 90`h percentile) percentile) percentile) 1270 — 42000 cfs 179 — 1270 cfs 100 — 179 cfs 5 — 100 cfs 29 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 100000 10000 1000 3 0 100 FL 10 1 o a a o a a o o a o o a a o a a o o a o o a a o a Ln o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 � o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 . . . . . . . . . . . . . . . . . . . . . . . . . 0 0 0 � Ln o Ln o Ln o Un o Un o Un o Un o Ln o Ln o Ln c) o N N M M It It LO LO CO to t- I,- CO CO CD CD T o Ir- Percent flow exceeded High Flow Trans. Flow Typical Flow Low Flow Figure 3.1. Flow Duration Curve for the Haw River at USGS 02096500. The above flow duration curve was used to determine the seasonality and flow regimes during which the exceedances of the pollutants occurred. It was also used to determine maximum daily pollutant load based on the flow duration and applicable standard. The applications of the flow duration curve for the Haw River are discussed in the following paragraphs. 3.2.4. Load Duration Curve A load duration curve is developed by multiplying the flow values along the flow duration curve by the pollutant concentrations and the appropriate conversion factors. As seen in Figure 3.2, allowable and existing loads are plotted against the flow recurrence interval. The allowable load is based on the water quality numerical criteria, margin of safety, and flow duration curve. The target line is represented by the line drawn through the allowable load data points and hence, it determines the assimilative capacity of a stream or river under different flow conditions. Any values above the line are exceeded loads and the values below the line are acceptable loads. Therefore, a load duration curve can help define the flow regime during which exceedances occur. Exceedances that occur during low -flow events are likely caused by continuous or point j17 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River source discharges, which are generally diluted during storm events. Exceedances that occur during high -flow events are generally driven by storm -event runoff. A mixture of point and non - point sources may cause exceedances during normal flows. Following paragraphs discuss procedures to estimate endpoints for turbidity and fecal coliform in the Haw River in order to identify assimilative capacity of the river in each flow condition and to identify the flow regime during which exceedances occur. 3.2.4.1. Turbidity Assimilative Capacity Existing TSS loads to the Haw River were determined by multiplying the observed TSS concentration by the flow observed on the date of observation and converting the result to daily loading values. The assimilative capacities of the water bodies were determined by multiplying the TSS concentration that is equivalent to a turbidity value of 50 NTU by the full range of measured flow values. Figures 3.2 presents the calculated load (scatter plot), power line (dotted line), and TMDL target loading (solid line) for the river. 10000.0 1000.0 100.0 U) 0 10.0 Cn H 1.0 0.1 ��■ P r v li i1r+_ 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent flow exceeded —Allowable Load Existing Load • Summer Existing Load - - - Power (Existing Load) Figure 3.2. TSS Load duration curve for the Haw River at the ambient station, B 1140000, from January 1997 through September 2003. 31 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River The assimilative capacity exceeded primarily during high -flows (< 10% of flow exceedance) and transitional -flows (10% —30% flow exceedance) in the Haw River. There was no TSS exceedance during typical -flows (30% - 90% flow exceedance) and low -flows (>90% flow exceedance). As evidenced by high loads during high and transitional flows suggest that the sources of turbidity could be from storm runoff and/or bank erosion. During the flow periods, runoff would carry a substantial amount of sediments and solid materials from impermeable as well as permeable land surfaces. The runoff can even transport the materials even from a far way lands. Bank erosion may be another result of high and transitional flows. When high volume and velocity runoff exceeds the resistance of the lateral (side) soil material, bank erosion occurs. Because soils in the Haw River watershed are sandy clay loam and clay loam, which contain considerable proportion of clay and silt (Soil Survey of Guildford County, NC, 1977), bank erosion often causes high flocculation of clay and silt, thereby creating high turbidity in the river. Furthermore, TSS load under natural background condition stayed under the turbidity standard of 50 NTU (34 mg/L) in the Haw River. The result was clearly explicated when a power line that represented average TSS loads under different flow conditions was drawn (Figure 3.2). The power line passed underneath the targeted line except during high flow period (<10% flow exceeded). The loads during high flow period is however unmanageable and hence is excluded in the TMDL estimation in this study. 3.2.4.2. Fecal Coliform Assimilative Capacity The fecal coliform assessment also used the load duration curve approach to determine existing load and assimilative capacity. As stated in Section 3.2.2, analysis was performed for the instantaneous standard of 400 counts / 100mL to determine the most conservative measure of impairment. Figures 3.3 present the calculated loads and the TMDL target loadings for the fecal coliform. In the Haw River, the criteria violations seem to have occurred at both high and low flows, suggesting that contamination due to fecal coliform occurred during both wet and dry weather 32 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River conditions (Figure 3.3). As evidenced by high fecal coliform concentrations during dry weather/low flow, it seems that the sources of fecal coliform were near the Haw River itself. Furthermore, as evidenced by high concentrations during high flows, it seems that the sources were also far away from the river. Therefore, the results indicate that the combination of sewer pipe leakage, failing septic system, and direct pipeline had elevated the fecal coliform during dry weather/low flow in the river. Correspondingly, non -point sources and sporadic sources such as sanitary sewer overflows had elevated the fecal coliform during high flows. 1.00E+15 • 1.00E+14 • • • � a 1.00E+13 • • • o • • ❑ ❑❑❑ ❑• 1.00E+12 • ❑• • •• ❑ ❑ ❑• ❑ • m LL ❑ ❑ ❑ • 1.00E+11 ❑•E* • 0 1.00E+10 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent flow exceeded Allowable Load ❑ Existing Load • Summer Existing Load Figure 3.3. Fecal coliform load duration curve for the Haw River at the ambient station, B 1140000, from January 1997 through September 2003. 3.3. Total Maximum Daily Loads (TMDL) Sections 3.2 described the processes and rationale to identify the endpoints, assimilative capacity, potential sources, and target loadings for each pollutant in the Haw River watershed. These efforts formed the basis for the TMDL process. Following sections describe the key components required by the TMDL guidelines to set the final TMDL allocation for the Watershed. Total Maximum Daily Load (TMDL) can be defined as the total amount of pollutant that can be assimilated by the receiving water body while achieving water quality standards. A TMDL can 33 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River be expressed as the sum of all point source loads (WLAs), non -point source loads (LAs), and an appropriate margin of safety (MOS), which takes into account any uncertainty concerning the relationship between effluence limitations and water quality. This definition can be expressed by equation 3.2: TMDL = ❑WLAs + ❑LAs + MOS---------------(3.2) The objective of the TMDL is to estimate allowable pollutant loads and to allocate the known pollutant source in the watershed in order to implement control measures and to achieve water quality standards. The Code of Federal Regulations (40 CFR § 130.2 (1)) states that TMDLs can be expressed in terms of mass per time, toxicity, or other appropriate measures. For TSS (surrogate measure for turbidity) and fecal coliform contamination, TMDLs are expressed as tons per day and counts per 100 milliliter respectively. The TMDLs represent the maximum one -day load the stream can assimilate and maintain the water quality criterion. Load duration curve approach was utilized to estimate the TMDL for TSS and fecal coliform. The systematic procedures adopted to estimate TMDLs are described below. 3.3.1. Margin of Safety (MOS) Conceptually, the MOS is included in the TMDL estimation to account for the uncertainty in the simulated relationship between the pollutants and the water quality standard. In this study, the MOS was explicitly included in following TMDL analysis by setting the TMDL target at 10 percent lower than the water quality target for turbidity and fecal coliform. 3.3.2. Target Reduction 3.3.2.1. Turbidity To determine the amount of turbidity reduction necessary to comply with the water quality criteria, exceedances of the estimated standard (34 mg TSS/L) were identified within the 10th to 95th percentile flow recurrence range. Because the assimilative capacity of the Haw River exceeded primarily during transitional -flow periods (between loth and 30th percentile) (Figure 3.4), a valid power curve for existing violated loads could not be estimated from the observed E Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River data. Therefore, a simple arithmetic mean of the exceedances was used as an estimate of the existing violated load. The allowable loads for each exceedance were calculated based on the TMDL target value, which include the 10 percent MOS. The target curve based on the allowable loads and the exceedances used for the existing load are shown in Figure 3.4. The estimates of load reduction are presented in Appendix 11.3. A 61 percent reduction in TSS load is required in order to meet the water quality standard, which in tern accounts for the 10 percent margin of 1000.0 ■ 100.0 ■ m c 0 10.0 H 1.0 10% 30% 50% 70% 90% Percent Flow Exceeded —Allowable load with MOS Existing load violation i safety. Figure 3.4. Load duration curve allowable TSS load and existing total TSS load violation in the Haw River. 3.3.2.2. Fecal Coliform The reduction for the instantaneous fecal coliform standard was estimated with the observed data that exceeded the applicable water quality standard (400 counts / 100 mL) within the 1 Oth to 95th percentile flow recurrence range. The reduction for the geometric mean was not estimated, because fecal coliform violation at the water quality standard, 200 count / 100 mL, was not observed (see § 1.3.2). Unlike in turbidity, the criteria violations seem to have occurred at both high and low flows in the Haw River. A power curve equation for the data point violating the water quality criterion 35 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River was estimated. The equation is presented in Equation 3.3. The coefficient of determination, R- Square, for the equation is 0.60; thus suggesting a reasonable fit of the equation. Y = (2E+12) * X (-1.643z) R-Square = 0.60-------------------------------(3.3) Where, Y = fecal coliform (Counts/100mL) and X = Percent Flow Exceeded. To present the TMDLs as a single value, the existing load was calculated from the power curve equation as the average of the load violations occurring when the flow (or load) exceeded at a frequency greater than 10 percent and less than 95 percent. Additionally, the average load was calculated by using percent flow exceedance in multiple of 5 percent. The allowable loadings for each exceedance were calculated from the TMDL target value, which includes the 10 percent MOS. The target curve based on the allowable load and the power curve based on the exceedances are shown in Figure 3.5. 1.00E+15 y 1.00E+14 0 U 1.00E+12 U d U_ 1.00E+11 -�— 0.000% 20.000% 40.000% 60.000% 80.000% 100.000% Percent flow exceeded —Allowable Load ■ Existing Load Voilation — —Power (Existing Load Voilation) Figure 3.5. Load duration curve showing allowable and existing loads of fecal coliform in the Haw River. The necessary percent reduction was calculated by taking a difference between the average of the power curve load estimates and the average of the allowable load estimates. For example, at Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River each recurrence interval between 10 and 95 (again using recurrence intervals in multiple of 5), the equation of the power curve was used to estimate the existing load. The allowable load was then calculated in a similar fashion by substituting the allowable load curve. The estimated values are given in Appendix 11.3. The estimated average fecal coliform loads were 1.144E+13 counts per day and 3.35E+12 counts per day for the power curve and allowable load curve, respectively. This equates to an average 77 percent reduction in load. 3.3.3. TMDL Allocation As identified by the above load duration curve method, significant amounts of TSS and fecal coliform are required to be reduced in the Haw River. A summary of reductions required is provided in Table 3.5. Table 3.5. Reduction Required for TSS and Fecal Coliform Pollutants Target with Existing Load Allowable Load Reduction MOS Required I. TSS' < 31 mg/L 183.16 tons/day 71.26 tons/day 61 % II. Fecal Coliform2 < 360 #/100mL 1.44E+13 #/day 3.35E+12 #/day 77 % 'TSS is used as a surrogate variable for turbidity 2Instantaneous measurement of fecal coliform is used. In order to meet the TMDL objectives, the reduction should be distributed over both point and non -point sources. A further analysis is, therefore, required to determine the breakdown between point source and non -point source loadings. 3.3.3.1. Waste Load Allocation (WLA) All TSS and fecal coliform transported from the wastewater facilities and the MS4 areas were assigned to the WLA components. The relative loading rates from the facilities are listed in Table 3.1. The relative loading rates from the MS4 areas were determined based on the report by USGS, 1999. The report describes TSS and fecal coliform transports under different land use conditions in the City of Charlotte and Mecklenburg County, North Carolina. A summary of the report and a description of method that was used to estimate relative percent contribution of TSS and fecal coliform from the urban and rural sources for this study are presented in Appendix 37 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 11.4. The estimated relative percent contribution from the MS4 and rural areas (non -point sources including non-MS4 area) are presented in Table 3.6. Table 3.6. Relative TSS and Fecal Coliform Contribution Rates for the Haw River. Pollutants Load from MS4 areas (%) Load from other areas (%) I. TSS II. Fecal Coliform 13 19 87 81 The assimilative capacity determined in Section 3.2.4 was split based on the relative contributions presented in Table 3.6 to determine the allocation for the MS4 areas. The results of these calculations are summarized in Table 3.7. The WLA associated with construction and other land management activities, as discussed in Section 3.1.2, is equivalent to the surface water quality standard for turbidity in that any construction activity cannot cause or contribute to a violation of the water quality standard. As discussed, these WLAs are and will be expressed as BMPs in the general or individual constriction permits rather than as numeric effluent limits. 3.3.3.2. Load Allocation (LA) All TSS and fecal coliform loadings from non -point sources such as non-MS4 urban land, agriculture land, and forestlands are reported as LAs. The relative loading rates from these areas were determined using the similar procedures as described in Section 3.3.3.1 (See also Appendix 11.4). The estimated relative percent contribution of TSS and fecal coliform from the non -point sources are presented in Table 3.7. The assimilative capacity determined in Section 3.2.4 was split based on the relative contributions presented in Table 3.6 to determine the allocation for the non -point sources. The results of these calculations are summarized in Table 3.7. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Table 3.7. Estimated TMDL and Load Allocation for TSS and Fecal Coliform for the Haw River Watershed. Pollutants Existing Load Construct- ion Activities NPDES MS4 WLA` LA MOS TMDL I. TSS 183.16 50 NTU 13.05 9.26 22.31 48.95 Explicit 71.26 (tons/day) 10 % U. Fecal 1.44E+13 NA 1.15E+12 6.37E+11 1.79E+12 1.56E+12 Explicit 3.35E+12 Coliform 10 % #/da ) 'WLA = MS4 + NPDES (including construction activities) 3.3.3.3. Study Limitation The available land cover for this study is outdated and fails to represent current land use condition. Therefore, the estimation of WLA in Table 3.7 is not authoritative. The estimation helps to provide understanding of the relative loads and should be viewed in light of the limited data available to quantify the actual contributions from each individual source. The primary focus of efforts to minimize future impairment should focus on the percent reductions and control of sources identified in the Source Assessment (see § 2). 3.3.4. Critical Condition and Seasonal Variation Critical conditions are considered in the load curve analysis by using an extended period of stream flow and water quality data, and by examining the flows (percent flow exceeded) where the existing loads exceed the target line. Seasonal variation is considered in the development of the TMDLs, because allocation applies to all seasons. In the load duration curves, the black mark inside a square box indicates pollutant transport during summer period. According to the load duration curve (Figure 3.2), the greatest frequency of exceedances of turbidity occurred during high -flow periods throughout the season. The result shows that wet weather under high -flow period is the critical period for turbidity in the Haw River. However, the existing load violation for fecal coliform occurred at all flow conditions throughout the season (Figure 3.3). Therefore, both dry and wet weathers are critical for fecal coliform. W Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 4. Deep River Impairment 4.1. Source Assessment 4.1.1. NPDES Wastewater Permits There were about 5 facilities that discharged wastewater continuously to the polluted portion of the Deep River and tributaries under the NPDES program (Table 4.1). The facilities were permitted to discharge up to 400 counts/100mL of fecal coliform daily. However, none of the facilities discharged wastewaters directly to the river (Appendix 11.2). Table 4. 1. NPDES Wastewater Permits in the Deep River ermit No. Facility Name Permitted Flow (MGD) Daily Permitted Limits Fecal Coliform (#/100mL) NC0038091 Southern Elementary School 0.0075 400 NCO038229 Southern Guilford High School 0.012 400 NCO055255 Crown Mobile Home Park 0.042 400 NCO041483 Plaza Mobile Home Park 0.003 400 Weekly Average Permitted Limits NCO024210 East Side WWTP 26 400 GM GM = Geometric Mean 4.1.2. NPDES General Permits All single family residences or domestic treatment facilities who discharge wastewaters not exceeding 1000 gallons per day in the Deep River watershed are subject to NC general permit NCG550000 and as such are required to not cause or contribute to violations of Water Quality Standards. Monitoring requirements for these facilities are outlined in Part I (page 2) of NCG550000 (httD://h2o.enr.state.nc.us/NPDES/documents/NCG55 Permit 2002.Ddf). A brief statement of maintenance activities is presented in Section 2.2.2.2. 4.1.3. NPDES Stormwater MS4s Within the Deep River watershed, there is one community that obtained an NPDES stormwater permit under the first phase of federal stormwater regulations, the City of Greensboro. The cities of High Point and Archdale are identified under the second phase of federal stormwater .O Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River regulations. The DWQ has not issued NPDES permit numbers to these cities except to the City of Greensboro. The permit number for the City of Greensboro is NCS000248. The ArcView software was utilized to overlay the shape files of NC municipalities over the Deep River watershed (discussed in Section 1.1) in order to estimate the land coverage of the MS4 areas. All of the urban lands in river were identified for the MS4 programs. 4.1.4. Livestock Populations The North Carolina Department of Agriculture (NCDA) regularly performs an agricultural census for each county of the state. This census includes estimated livestock populations in each county, as shown in Table 4.2 for the Deep River watershed. Table 4.2. Estimated Livestock population in the Deep River watershed above Randleman (NCDA). Livestock I Counties Guilford Forsyth Randolph Swine (2002) 8.6 <1 34 Cattle (2003) 16 7.2 39.1 Beef Cow (2003) 7.0 3.8 16.9 Milk Cow (2003) 2.0 <0.2 4.4 Broiler (2002) 500 <500 54,300 Turkey (2002) <500 <500 <500 Chickens (2002) 100 <50 1,200 (Source: http://www.ncagr.com/stats/Cn SUsumm/) Year of the census is reported for each type of livestock. Counts are reported in thousands. 4.1.5. Septic Tanks Some residences in the Deep River watersheds use septic tanks. A majority of the residents seem to be connected to sewer systems (Table 4.3). 41 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Table 4.3. Estimated housing units using septic systems in the Deep River watershed in 2002. Number of Housing Percentage of Housing County Units Number of Septic System Units with Septic Systems Guilford 189,272 687 0.36 IFors th 138,573 436 0.31 Randolph 56,701 8531 1.50 Source for housing unit: http://www.deh.enr.state.nc.us/oww/Program improvement_team/Pit_Index.htm Source for septic system: http://quickfacts.census. aov/q fd/states/ The Eastern portion of the Deep River, where the City of High Point is located, has the highest population density. The majority of the housing units were connected to the sewer system in 1990, and more households have probably converted from septic to sewer disposal over the last decade. The Midwestern portion of the Deep River watershed includes recent expansion of High Point. Most of the housing units in this portion are in the process of converting form septic tank to sewer system. 4.2. Technical Approach As discussed in Section 3.2, a load duration approach was used to identify source types, specify assimilative capacity of a stream, and to estimate magnitude of load reduction required to meet the water quality standard. Following paragraphs demonstrate systematic procedures to develop a load duration curve for the Deep River. 4.2.1. Endpoint for Fecal Coliform The TMDL objectives require the instream fecal coliform concentrations to meet both the instantaneous standard of 400 counts /100mL and the geometric mean standard of 200 counts / 100mL. As discussed in Section 1.3.2, an additional intensive fecal coliform monitoring program with regards to the standards specification requiring five samples per 30-day period was not launched in the Deep River due to limitation in time. Therefore, evaluation of fecal coliform contamination in terms of geometric mean was not conducted for the river. Only instantaneous standard is considered to be the endpoints for the determination of the fecal colifrom TMDL for the river. 42 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 4.2.2. Flow Duration Curve Daily stream data collected from January 1928 through September 2003 at the USGS gage station, 02099500, near Randleman, was used to develop flow duration curves. The flow duration curve is shown in Figure 4.1. Flow statistics as generated by the curves are presented in Table 4.4. Table 4.4. Flow Statistics for the Deep River. High Flow Transitional Flow Typical Flow Low Flow (< 1 Orh percentile) (Between 10`h and 301h (Between 301h and 901h (> 901h percentile) percentile) percentile) 244 — 12000 cfs 29 — 244 cfs 17 — 29 cfs 1 — 17 cfs 100000 High Flow Transitional Flow Typical Flow Low Flow Figure 4.1. Flow Duration Curve for the Deep River at USGS 02099500. The flow duration curve was used to determine the seasonality and flow regimes during which the exceedances of the pollutants occurred. It was also be used to determine maximum daily 43 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River pollutant load based on the flow duration and applicable standard. The applications of the flow duration curve are discussed in the following paragraphs. 4.2.3. Load Duration Curve As discussed in Section 3.2.4, a load duration curve is developed by multiplying the flow values along the flow duration curve by the pollutant concentrations and the appropriate conversion factors. As seen in Figure 4.2, allowable and existing loads are plotted against the flow recurrence interval. The allowable load is based on the water quality numerical criteria, margin of safety, and flow duration curve. 4.2.4.2. Fecal Coliform Assimilative Capacity The fecal coliform assessment used the load duration curve approach to determine existing load and assimilative capacity. As stated in Section 4.2.1, analysis was performed for the instantaneous standard of 400 counts / 100mL to determine the most conservative measure of impairment. Figures 4.2 present the calculated loads and the TMDL target loadings for the fecal coliform. 1.00E+15 1.00E+13 WEF11 NEII M 1.00E+11 • ' E' o 1.00E+09 0 U 1.00E+07 0 1.00E+05 LL 0 0 0 0 0 0 0 0 8-0 0 810 O O N M � M M ti 000 O O V— Pecent Flow Exceeded ❑ Existing load —Allowable load • Summer Existing Load Figure 4.2. Fecal coliform load duration curve for the Deep River at the ambient station, B4615000, from January 1997 through September 2003. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River There were no criteria violations during low flows in the Deep River (Figure 4.2). It seems that the sources like sewer pipe leakage, failing septic system, and direct pipeline are not the problems in the river. The criteria violations were seen to occur mostly during high and transitional flows, suggesting that the combination of non -point and sporadic sources would be the problem in the river. 4.3. Total Maximum Daily Loads (TMDL) Sections 4.2 described the processes and rationale to identify the endpoints, assimilative capacity, potential sources, and target loadings for fecal coliform in the Deep River watershed. These efforts formed the basis for the TMDL process. The key components required by the TMDL guidelines to set the final TMDL allocation for the watershed is defined by the equation 4.1. TMDL = ❑WLAs + ❑LAs + MOS---------------(4.1) Where, WLA is waste load allocation (point source), LA is load allocation (non -point source), and MOS is marginal of safety. Detail explanation of the equation is given in Section 3.3. 4.3.1. Margin of Safety (MOS) The MOS was explicitly included in following TMDL analysis by setting the TMDL target at 10 percent lower than the water quality target for fecal coliform. 4.3.2. Target Reduction The reduction for the instantaneous fecal coliform standard was estimated with the observed data that exceeded the applicable water quality standard (400 counts / 100 mL) within the 1 Oth to 95th percentile flow recurrence range. The criteria violations were occurring through out the flow regime except during low flow periods (Figure 4.3). The existing loads at every 5th percentile flow recurrence in the Deep River were calculated from the power curve equation (Equation 4.1). The allowable loadings were calculated from the TMDL target value, which included the 10 percent MOS. Within the 101h to 95th percentile flow recurrence range, the average of the two sets of loading estimates was calculated and the percent of the existing load that exceeded the target was determined. The estimated values are presented 45 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River in Appendix 11.3. To meet the instantaneous limit and to account for the 10 percent MOS, about 75 percent reduction in fecal coliform is required. A summary of reductions required is provided in Table 4.5. Y = (2E+11) * X (-1.9614) R-Square = 0.66-------------------------------(4.2) Where, Y = fecal coliform (Counts/100mL) and X = Percent Flow Exceeded. Table 4.5. Reduction Required for Fecal Coliform Pollutants Target with MOS Existing Load Allowable Load Reduction Required Fecal Coliform' < 360 #/100mL 2.47E+12 #/day 6.22E+11 #/day 75 % 'Instantaneous measurement of fecal coliform is used. 1.00E+14 0 1.00E+13 J ^ E m L `0 1.00E+12 o � U o �U 0 1.00E+11 LL 1.00E+10 +-- 10.00% 30.00% 50.00% 70.00% 90.00% Percent Flow Exceeded —Allowable load Existing Load Violation — —Power (Existing Load Violation) Figure 4.3. Load duration curve showing allowable and existing loads of fecal coliform in the Deep River .o Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 4.3.3. TMDL Allocation As identified by the above load duration curve method, significant quantities of fecal coliform are required to be reduced in the Deep River. In order to meet the TMDL objectives, the reduction should be distributed over both point and non -point sources. A further analysis is, therefore, required to determine the breakdown between point source and non -point source loadings. 4.3.3.1. Waste Load Allocation (WLA) All fecal coliform transported from the MS4 areas and wastewater facilities were assigned to the WLA components. The relative loading rates from the MS4 areas were determined as described in Section 3.3.3.1. The estimated relative percent contribution from the MS4 and rural areas (non -point sources including non-MS4 area) are presented in Table 4.6. Table 4.6. Relative Fecal Coliform Contribution Rates for the Deep River. Pollutants Load from MS4 areas (%) Load from other areas (%) Fecal Coliform 31 69 The assimilative capacity determined in Section 4.2.2 was split based on the relative contributions presented in Table 4.6 to determine the allocation for the MS4 areas. The results of these calculations are summarized in Table 4.7. 4.3.3.2. Load Allocation (LA) All fecal coliform loadings from non -point sources such as non-MS4 urban land, agriculture and forested lands were reported as LAs. The relative loading rates from these areas were determined using the similar procedures as described in Section 3.3.2.1 (See also Appendix 11.3). The estimated relative percent contributions of fecal coliform from the non -point sources are presented in Table 4.6. 47 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River The assimilative capacity determined in Section 4.2.3 was split based on the relative contributions presented in Table 4.6 to determine the allocation for the non -point sources. The results of these calculations are summarized in Table 4.7. Table 4.7. Estimated TMDL and Load Allocation for Fecal Coliform for the Deep River Watershed. Pollutants Existing NPDES MS4 WLA' LA MOS TMDL Load a Fecal 2.47E+12 3.95E+ll 1.92E+11 5.87E+ll 3.42E+10 Explicit 6.22E+11 Coliform 10 % #/da ) 'WLA = MS4 + NPDES 4.3.3.3. Study Limitation The available land cover for this study is outdated and fails to represent current land use condition. Therefore, the primary focus of efforts to minimize future impairment should focus on the percent reductions and control of sources identified in the Source Assessment (see § 2). 4.3.4. Critical Condition and Seasonal Variation According to the load duration curve (Figure 4.2), there were no violations due to fecal coliform during low —flow events in the Deep River. The violation seems to occur during high -flow events only. Therefore, wet weather is critical for fecal coliform in the Deep River. M. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 5. Third Fork Creek Impairment 5.1. Source Assessment The DWQ staff noticed several developing activities such as land clearing and site preparation for residential buildings, commercial areas, roads, and highways being conducted in the Third Fork Creek watershed. These activities are the main sources of turbidity. Surface runoff carries sediments and solids from these lands to the creek and increases turbidity level. In addition, point sources such as waste water treatment plants (WWTP) and MS4 areas are also responsible for TSS increment in a water body. 5.1.1. NPDES Wastewater Permits There was only one facility, Brenntag Southeast, Inc., under the NPDES program that discharged wastewater to the Third Fork Creek (Table 5.1). The facility was permitted to discharge up to 30 mg/L of TSS daily. Table 5.1. NPDES Wastewater Permits in the Third Fork Creek Daily Permitted Permitted Limits Permit No. Facility Name Flow (MGD) TSS (mg/L) NCO086827 Brenntag Southeast, Inc. 10.0144 30 5.1.2. NPDES General Permits All construction activities in the Third Fork Creek watershed that disturb one or more acres of land are subject to NC general permit NCGO10000 and as such are required to not cause or contribute to violations of Water Quality Standards. As stated in Permit NCGO10000, page 2, "The discharges allowed by this General Permit shall not cause or contribute to violations of Water Quality Standards. Discharges allowed by this permit must meet applicable wetland standards as outlined in 15A NCAC 2B .0230 and .0231 and water quality certification requirements as outlined in 15A NCAC 211.0500". Monitoring requirements for these construction activities are briefly explained in Section 3.1.2. 5.1.3. NPDES Stormwater MS4s The City of Durham in the Third Fork Creek watershed falls under the Phase I NPDES storm water program for MS4. All of the urban lands in the watershed were, therefore, occupied by the city. .• Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 5.2. Technical Approach As discussed in Section 3.2, a load duration approach was adopted to determine impairment loads under different flow conditions to identify source types, specify assimilative capacity of a stream, and to estimate magnitude of load reduction required to meet the water quality standard. Following paragraphs explains its application for developing turbidity TMDL for the Third Fork Creek. 5.2.1. Endpoint for Turbidity As discussed in Section 3.2.1, total suspended solid (TSS) was selected as a surrogate measure for the Third Fork Creek. In order to observe relationship between TSS and turbidity in the creek, a regression equation between the two parameters was developed using the observed data collected from April 2004 through September 2003 in the ambient station, B3025000. The equation is shown in Equation 5.1. The coefficient of determination between the two parameters was 0.73, suggesting a significant relationship. Y = 0.0068 X 2 + 0.0827X + 7.7524 R-Square = 0.73----------------------(5.1) Where, Y = TSS in mg/1 and X = turbidity in NTU. Equation 5.2 suggests that the Third Fork Creek yielded approximately 7.75 mg/L of TSS during natural condition (NTU = 0). However, the creek showed a polynomial relationship between TSS and turbidity. Therefore, the corresponding TSS value at the turbidity standard of 50 NTU was 29 mg/L. 5.2.2. Flow Duration Curve Daily stream data collected from January 1982 through September 2003 at the USGS gage station, 0209741955, at SR1100 near Glenlee, was used to develop flow duration curves. The gage station drains about 21 sq. miles of the Northeast Creek watershed. The watershed area is slightly bigger than the Third Fork Creek watershed (16.5 sq mi). The watershed is almost similar in characteristic and is adjacent to the Third Fork Creek at the Eastern side. Therefore, flows of the Third Fork Creek were estimated using "area ratio method." In the method, the area ratio is first estimated by dividing the area of the Third Fork Creek watershed by the area of the Northeast Creek watershed. The flows of the Northeast Creek are then multiplied by the ratio to estimate the flows for the Third Fork Creek. The flow duration curve for the Third Fork Creek 50 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River watershed is shown in Figure 5.1. Flow statistics as generated by the curves are presented in Table 5.2. Table 5.2: Flow Statistics for the Third Fork Creek. High Flow Transitional Flow Typical Flow Low Flow (< IOth percentile) (Between loth and 3Oth (Between 30th and 90th (> 90th percentile) percentile) percentile) 47 —2616 cfs 5 — 47 cfs 3 — 5 cfs 1 —3 cfs 10000 1000 100 0 10 U- 1 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent flow exceeded High Flow Transitional Flow Typical Flow Low Flow Figure 5.2. Flow Duration Curve for the Third Fork Creek. Flows from the Northeast Creek at USGS 0209741955 were used to estimate flows for the Third Fork Creek. The flow duration curve was used to determine the seasonality and flow regimes during which the exceedances of the pollutants occurred. It was also used to determine maximum daily pollutant load based on the flow duration and applicable standard. 5.2.3. Load Duration Curve As discussed in Section 3.2.4, a load duration curve is developed by multiplying the flow values along the flow duration curve by the pollutant concentrations and the appropriate conversion factors. As seen in Figure 5.2, allowable and existing loads are plotted against the flow 51 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River recurrence interval. The allowable load is based on the water quality numerical criteria, margin of safety, and flow duration curve. Following paragraphs discusses procedures to estimate endpoints for turbidity in the Third Fork Creek in order to identify assimilative capacity of the creek in each now conditions and to identify the flow regime during which exceedances occur. 5.2.4.1. Turbidity Assimilative Capacity Existing TSS loads to the Third Fork Creek was determined by multiplying the observed TSS concentration by the flow observed on the date of observation and converting the result to daily loading values. The assimilative capacities of the water bodies were determined by multiplying the TSS concentration that is equivalent to a turbidity value of 50 NTU by the full range of measured flow values. Figure 5.2 present the calculated load, (scatter plot) power line (dotted line), and the TMDL target loading (solid line) for the creek. 1000 100 y 10 2 � 1 • o • 0 • (n 0.1 ❑ ❑ ❑ a Cn ~ 0.01 0 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r N M Iq W) 0 0 0 0 0 OD 1` 00 M O O Existing load -Allowable load • Summer Existing Load - - - Power (Existing load) Figure 5.2. TSS Load duration curve for Third Fork Creek at the coalition station, B3025000, from April 2000 through September 2003. 52 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Except during low flow periods, the assimilative capacity of the Third Fork Creek exceeded the targeted values (Figure 5.2). The result, therefore, suggests that non -point sources alone could have increased turbidity level in the creek. Furthermore, the power line that represented average existing TSS loads clearly explicated that the TSS loads under natural background condition did not exceed the turbidity standard of 50 NTU (29 mg/L) in the Third Fork Creek (Figure 5.2). The power line passed underneath the targeted line except during high flow period (<10% flow exceeded), which is indeed unmanageable and hence is excluded in the TMDL estimation in this study. 5.3. Total Maximum Daily Loads (TMDL) Sections 5.2 described the processes and rationale to identify the endpoints, assimilative capacity, potential sources, and target loadings for each pollutant in the Third Fork Creek watershed. These efforts formed the basis for the TMDL process. The key components required by the TMDL guidelines to set the final TMDL allocation for the watershed is defined by the equation 5.2. TMDL = ❑WLAs + ❑LAs + MOS---------------(5.2) Where, WLA is waste load allocation (point source), LA is load allocation (non -point source), and MOS is marginal of safety. Detail explanation of the equation is given in Section 3.3. Following sections describe the key components required by the TMDL guidelines to set the final TMDL allocation for the Watershed. 5.3.1. Margin of Safety (MOS) The Margin of Safety was explicitly included in following TMDL analysis by setting the TMDL target at 10 percent lower than the water quality target for turbidity. 5.3.2. Target Reduction To determine the amount of turbidity reduction necessary to comply with the water quality criteria, exceedances of the estimated standard (29 mg TSS/L) were identified within the 10th to 95th percentile flow recurrence range. A power curve through the data point violating the water quality criterion was overlaid on the graph (Figure 5.3). The power curve equation is presented 53 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River in Equation 5.2. The correlation coefficient, R-Square, for the power curve is 0.71; thus suggesting a reasonable fit of the curve. Y = 0.3208 * X (-13974) R-Square = 0.71---------------------------(5.2) Where, Y = Turbidity (mg/L) and X = Percent Flow Exceeded. The criteria violations occurred through out the typical flow regime (Figure 5.3). As described in Section 3.3, the loading estimates based on the power curve are presented in Appendix 4. Approximately 53 percent reduction in turbidity is required in order to meet the water quality standard and to account for the 10 percent of MOS. A summary of reductions required is provided in Table 5.3. Table 5.3. Reduction Required for TSS in the Third Fork Creek Pollutants AIL Target with MOS Existing Load Allowable Load Reduction Required TSS' < 26 mg/L 1.58 tons/day 0.75 tons/day 53 % 'TSS is used as a surrogate variable for turbidity 10 c� U 0 1 � c� 0 J N Cn Ir 0.1 10.00% 30.00% 50.00% 70.00% 90.00% Percent Flow Exceeded Allowable Load ■ Existing Load Violated 7 —Power (Existing Load Violated) Figure 5.3. Load duration curve showing allowable and existing loads violation of the Third Fork Creek. 54 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 5.3.3. TMDL Allocation As identified by the above load duration curve method, significant amounts of TSS are required to be reduced in the Third Fork Creek. In order to meet the TMDL objectives, the reduction should be targeted towards non -point sources and MS4 areas. 5.3.3.1. Waste Load Allocation (WLA) All TSS transported from the MS4 areas and waste load facility, Brenntag Southeast, were assigned to the WLA components. The relative loading rates from the MS4 areas are discussed in Section 3.3.3. A summary of the report and a description of method that was used to estimate relative percent contribution of TSS from the urban and rural sources are presented in Appendix 11.3. The estimated relative percent contribution from the MS4 and rural areas (non -point sources including non-MS4 area) are presented in Table 5.4. Table 5.4. Relative TSS Contribution Rates for the Third Fork Creek. Pollutants Load from MS4 areas (%) Load from other areas (%) TSS 48 52 The assimilative capacity determined in Section 5.2.3 was split based on the relative contributions presented in Table 5.4 to determine the allocation for the MS4 areas. The results of these calculations are summarized in Table 5.5. The WLA associated with construction and other land management activities, as discussed in Section 5.1.2, is equivalent to the surface water quality standard for turbidity in that any construction activity cannot cause or contribute to a violation of the water quality standard. As discussed, these WLAs are and will be expressed as BMPs in the general or individual constriction permits rather than as numeric effluent limits. 5.3.3.2. Load Allocation (LA) All TSS loadings from non -point sources such as non-MS4 urban land, agriculture land, and forested land were reported as LAs. The relative loading rates from these areas were determined using the similar procedures as described in Section 3.3.2. (See also Appendix 11.3.) The 55 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River estimated relative percent contribution of TSS from the non -point sources is presented in Table 5.5. Table 5.5. Estimated TMDL and Load Allocation for TSS for the Third Fork Creek Watershed. Pollutants Existing Construct- NPDES MS4 WLA' LA MOS TMDL Load ion Activities TSS 1.58 50 NTU 0.002 0.36 0.36 0.39 Explicit 0.75 (tons/day) I I I 1 10 % 'WLA = MS4 + NPDES (including construction activities) 5.3.3.3. Study Limitation The available land cover for this study is outdated and fails to represent current land use condition. Therefore, the estimation of WLA in Table 5.5 is not authoritative. The primary focus of efforts to minimize future impairment should be on the percent reductions and control of sources identified in the Source Assessment (see § 2). 5.3.4. Critical Condition and Seasonal Variation According to the load duration curve (Figure 5.2), the greatest frequency of exceedances of turbidity occurred during high -flow periods throughout the season. The result shows that wet weather under high -flow period is the critical period for turbidity in the Third Fork Creek. 56 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 6. Dan River Impairment 6.1. Source Assessment As discussed in Section 1.1, population growth in Rockingham County and Stokes County are alarming. Several developing activities such as land clearing and site preparation for residential buildings, commercial areas, roads, and highways being conducted in the Dan River watershed. These activities are the main sources of turbidity. Surface runoff carries sediments and solids from these lands to the river and increases turbidity level. Transport of total suspended solids (TSS) from a developed land is discussed in Section 2.1. In addition, point sources such as waste water treatment plants (WWTP) and MS4 areas are also responsible for TSS increment in a water body. 6.1.1. NPDES Wastewater Permits There were about 26 facilities under the NPDES program that discharged wastewater to the Dan River and its tributaries (Table 6.1). Of the 26 facilities, four facilities - Kobewireland Copper Products, Madison WWTP, Danbury WWTP, and North Stokes High School - discharged wastewater directly to the Dan River (Appendix 11.2). Except JPS Elastomerics Corp -Caro Plt, the facilities were permitted to discharge up to 45 mg/L of TSS daily (Table 6.1). These facilities are located in North Carolina. Statistics of the facilities in Virginia are not documented in this study. 57 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Table 6.1. NPDES Wastewater Permits in the Dan River Permit No. Facility Name Mift Permitted Flow (MGD) Daily Permitted Limits TSS (mg/L) NC0075027 Cains Way Mobile Home Park 0.0432 45 NC0078115 Greystone Subdivision WWTP 0.032 45 NC0083933 Rangecrest Road WWTP 0.06 45 NC0060461 WWTP 0.385 45 _Abington NC0037311 Creekside Manor Rest Home 0.01 45 NC0028746 Briarwood Subdivision WWTP 0.05 45 NC0056791 Horizons Residential Care Ctr 0.015 45 NC0035173 Kobewireland Copper Products Incorporated 0.025 45 NC0044962 North Stokes High School 0.0115 45 NC0067091 Mikkola Downs WWTP 0.072 45 NC0029777 Stokes Correctional Center WWTP 0.0132 45 NC0059251 Quail Acres Mobile Home Park 0.018 45 NC0060542 Gold Hill Mobile Home Park 0.0176 45 NC0044750 Britthaven Of Madison 0.025 45 NC0037001 Bethany Elementary School 0.01 45 NC0003441 JPS Elastomerics Corp -Caro Plt 0.015 135 NCO044954 South Stokes High School 0.0173 45 NC0079049 R.H. Johnson Construction WWTP 0.06 45 NC0057720 Twin Lakes Mobile Home Park 0.04 45 NC0003492 R J Reynolds Tobacco Co - Brook Cove 0.02 45 Weekly Average Permitted Limits NC0021075 Madison WWTP 0.775 45 NC0082384 Danbury WWTP 0.1 45 NC0028011 Stoneville WWTP 0.25 45 NC0021873 IMayodan WWTP 4.5 145 NC0025526 alnut Cove WWTP 0.5 45 NC0024406 ZlewsCreek Steam Station 0.01 145 6.1.2. NPDES General Permits All construction activities in the Dan River watershed that disturb one or more acres of land are subject to NC general permit NCGO10000 and as such are required to not cause or contribute to violations of Water Quality Standards. As stated in Permit NCGO10000, page 2, "The discharges allowed by this General Permit shall not cause or contribute to violations of Water Quality Standards. Discharges allowed by this permit must meet applicable wetland standards as outlined in 15A NCAC 2B .0230 and .0231 and water quality certification requirements as Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River outlined in 15A NCAC 2H .0500". Monitoring requirements for these construction activities are briefly explained in Section 3.1.2. 6.1.3. NPDES Stormwater MS4s There was no municipality under the NPDES storm water program in the Dan River watershed. 6.2. Technical Approach As discussed in Section 3.2, a load duration approach was adopted to identify source types, specify assimilative capacity of a stream, and to estimate magnitude of load reduction required to meet the water quality standard. In Section 3.2, essential components of developing a load duration curve are discussed in detail. Following paragraphs explains its application for developing turbidity TMDL for the Dan River. 6.2.1. Endpoint for Turbidity As discussed in Section 3.2.1, total suspended solid (TSS) was selected as a surrogate measure for the Dan River. In order to observe relationship between TSS and turbidity in the River, a regression equation was developed using the observed data collected from February 1997 through March 2004 in the ambient station, N2300000. The equation is shown in Equation 6.1. The coefficient of determination between the two parameters was 0.92, thereby suggesting a significant relationship. Y = 0.91 X + 1.105 R-Square = 0.92----------------------(6.1) Where, Y = TSS in mg/1 and X = turbidity in NTU. Equation 6.1 suggests that the Dan River yielded approximately 1.105 mg/L of TSS under natural condition (NTU = 0). The river increased TSS on an average by 0.91 mg/L for each turbidity increase. Correspondingly, the river yielded 47 mg/L of TSS at the turbidity standard of 50 NTU. 6.2.2. Flow Duration Curve Daily stream data collected from January 1939 through September 2003 at the USGS gage station, 02071000 near Wentworth was used to develop flow duration curves. The flow duration curve for the Dan River watershed is shown in Figure 6.1. Flow statistics as generated by the curves are presented in Table 6.2. 59 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Table 6.2: Flow Statistics for the Dan River. High Flow Transitional Flow Typical Flow Low Flow (< 10`h percentile) (Between 10th and 301h (Between 30th and 90th (> 90th percentile) percentile) percentile) 2020 — 47800 cfs 601 — 2020 cfs 396 — 601 cfs 61 — 396 cfs 100000 High Flow Transitional Flow Typical Flow Low Flow Figure 6.2. Flow Duration Curve for the Dan River at USGS 02071000 near Wentworth. The flow duration curve was used to determine the seasonality and flow regimes during which the exceedances of the pollutants occur. It was also used to determine maximum daily pollutant load based on the flow duration and applicable standard. 6.2.3. Load Duration Curve As discussed in Section 3.2.4, a load duration curve is developed by multiplying the flow values along the flow duration curve by the pollutant concentrations and the appropriate conversion factors. As seen in Figure 6.2, allowable and existing loads are plotted against the flow :1 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River recurrence interval. The allowable load is based on the water quality numerical criteria, margin of safety, and flow duration curve. Following paragraphs discusses procedures to estimate endpoints for turbidity in the Dan River in order to identify assimilative capacity of the River in each flow conditions and to identify the flow regime during which exceedances occur. 6.2.4.1. Turbidity Assimilative Capacity Existing TSS loads to the Dan River was determined by multiplying the observed TSS concentration by the flow observed on the date of observation and converting the result to daily loading values. The assimilative capacities of the water bodies were determined by multiplying the TSS concentration that is equivalent to a turbidity value of 50 NTU by the full range of measured flow values. Figure 6.2 present the calculated load (scatter plot), power line (dotted line), and the TMDL target loading (solid line) for the creek. 10000.00 1000.00 ❑ 0 100.00 0 ❑ 0 cn • � 0 � ' ' 10.00 1.00 0 0 0 0 0 0 0 0 0 0 0 0 0 -10 0 0 0 0 0 0 0 0 o Ln o Ln o 0 o Ln o Ln o Ln o 0 o Ln o 0 o Ln o r tV tV M M 4 4 Ln Ln to to F- F- co co a) o) O ❑ Existing load -Allowable load • Summer Existing Load - - - Power (Existing load) Figure 6.2. TSS Load duration curve for the Dan River at the ambient station, N2300000, from February 1997 through March 2004. oil Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River The assimilative capacity of the Dan River also exceeded the targeted values during all flow periods except during low flow period (6.2). The result suggests that non -point sources alone could have elevated turbidity level in the river. Furthermore, the power line that represented average existing TSS loads clearly explicated that the TSS loads under natural background condition did not exceed the turbidity standard of 50 NTU (47 mg/L) in the Dan River (Figure 5.2). The power line passed underneath the targeted line except during high flow period (<10% flow exceeded), which is indeed unmanageable and hence is excluded in the TMDL estimation in this study. 6.3. Total Maximum Daily Loads (TMDL) Sections 6.2 described the processes and rationale to identify the endpoints, assimilative capacity, potential sources, and target loadings for each pollutant in the Dan River watershed. These efforts formed the basis for the TMDL process. The key components required by the TMDL guidelines to set the final TMDL allocation for the watershed is defined by the equation 6.2. TMDL = ❑WLAs + ❑LAs + MOS---------------(6.2) Where, WLA is waste load allocation (point source), LA is load allocation (non -point source), and MOS is marginal of safety. Detail explanation of the equation is given in Section 3.3. Following sections describe the key components required by the TMDL guidelines to set the final TMDL allocation for the Watershed. 6.3.1. Margin of Safety (MOS) The Margin of Safety was explicitly included in following TMDL analysis by setting the TMDL target at 10 percent lower than the water quality target for turbidity. 6.3.2. Target Reduction To determine the amount of turbidity reduction necessary to comply with the water quality criteria, exceedances of the estimated standard (47 mg TSS/L) were identified within the 10th to 95th percentile flow recurrence range. A power curve through the data point violating the water quality criterion was overlaid on the graph (Figure 6.3). The power curve equation is presented % Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River in Equation 6.2. The correlation coefficient, R-Square, for the power curve is 0.96; thus suggesting a reasonable fit of the curve. Y = 42.578 * X (-1.5174) R-Square = 0.96---------------------------(6.2) Where, Y = Turbidity (mg/L) and X = Percent Flow Exceeded. The criteria violations occurred through out the typical flow regime (Figure 6.3). As described in Section 3.3.2, the loading estimates based on the power curve are presented in Appendix 11.3. Approximately 59 percent reduction in turbidity is required in order to meet the water quality standard and to account for the 10 percent of MOS. A summary of reductions required is provided in Table 6.3. Table 6.3. Reduction Required for TSS in the Dan River Pollutants Target with MOS Existing Load Allowable Load Reduction Required TSS' < 42 mg/L 248.20 tons/day 101.74 tons/day 59 % 'TSS is used as a surrogate variable for turbidity 1000 c� U ■ 0 100 c� 0 Cn Cn H 10 10.00% 30.00% 50.00% 70.00% 90.00% Perecent Flow Exceeded Allowable Load ■ Existing Exceeded Load —Power (Existing Exceeded Load) M Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Figure 6.3. Load duration curve showing allowable and existing loads of turbidity in the Dan River. 6.3.3. TMDL Allocation As identified by the above load duration curve method, significant amounts of TSS are required to be reduced in the Dan River. In order to meet the TMDL objectives, the reduction should be distributed over both point and non -point sources. A further analysis is, therefore, required to determine the breakdown between point source and non -point source loadings. 6.3.3.1. Waste Load Allocation (WLA) All contributions of TSS from the 26 facilities listed in Table 6.1 were reported as the WLA components. The relative loading rates from the facilities are presented in Table 6.4. The WLA associated with construction and other land management activities, as discussed in Section 6.1.2, is equivalent to the surface water quality standard for turbidity in that any construction activity cannot cause or contribute to a violation of the water quality standard. As discussed, these WLAs are and will be expressed as BMPs in the general or individual constriction permits rather than as numeric effluent limits. 6.3.3.2. Load Allocation (LA) All TSS loadings from non -point sources such as urban, agriculture, and forested lands were reported as LAs. The estimated relative percent contribution of TSS from the non -point sources is presented in Table 6.4. Table 6.4. Estimated TMDL and Load Allocation for TSS for the Dan River Watershed. Pollutants Existing Construct- NPDES MS4' WLA2 LA MOS TMDL Load ion Activities TSS 248.20 50 NTU 1.21 0 1.21 100.53 Explicit 101.74 (tons/day) I I 1 10 % 'There are no MS4 areas in the Dan River watershed. 2WLA = MS4 + NPDES (including construction activities). A Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 6.3.3.3. Study Limitation The available land cover for this study is outdated and fails to represent current land use condition. Therefore, the estimation of WLA in Table 6.4 is not authoritative. The primary focus of efforts to minimize future impairment should focus on the percent reductions and control of sources identified in the Source Assessment (see § 2). 6.3.3.4. Critical Condition and Seasonal Variation The greatest frequency of exceedances of turbidity in the Dan River occurred during high -flow periods throughout the season (Figure 6.2). The result shows that wet weather under high -flow period is the critical period for turbidity in the Dan River. 7. Summary and Future Consideration This report presents the development of Total Maximum Daily Loads (TMDLs) for the four water bodies in North Carolina: Haw River, Deep River, Third Fork Creek, and Dan River. The Haw River is located in the Cape Fear River Basin (CFRB) and is impaired due to fecal coliform and turbidity. The Deep River and the Third Fork Creek are also located in the CFRB and are impaired due to fecal coliform and turbidity respectively. The Dan River is located in the Roanoke River Basin and is impaired due to turbidity. Available water quality data were reviewed to determine the frequency of exceedances. A load duration curve method was applied to determine the critical periods and the sources that lead to exeedances of the standard. The necessary percent reduction to meet the TMDL requirement was then calculated by taking a difference between the average of the power curve load estimates and the average of the allowable load estimates. The summary of the results is as follows: ❑ About 61 percent reduction in turbidity and 77 percent reduction in fecal coliform are required in order to meet the water quality standard in the Haw River. Storm runoff and bank erosion are seen to be responsible for the exceedance of turbidity, whereas both point and non -point sources are responsible for the exceedance of fecal coliform. ❑ About 75 percent reduction in fecal coliform is required in order to meet the water quality standard in the Deep River. The combination of non -point and sporadic sources are the major problem in the river. ❑ About 53 percent reduction in turbidity is required in order to meet the water quality standard in the Third Fork Creek. Non -point sources are the major problem in the creek. :e Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River ❑ About 59 percent reduction in turbidity is required in order to meet the water quality standard in the Dan River. Non -point sources are the major problem in the River. 7.1 Stream Monitoring Stream monitoring should continue on a monthly interval at the existing ambient monitoring stations. The continued monitoring of TSS and fecal coliform concentrations will allow for the evaluation of progress towards the goal of reaching water quality standards by comparing the instream data to the TMDL target. Furthermore, to comply with EPA guidance, North Carolina may adopt new bacteria standards utilizing Escherichia coli (E. coli) or enterococci in the near future. Thus, in future, monitoring efforts to measure compliance with this TMDL should include using E. coli or enterococci. Per EPA recommendations (EPA, 2000b), if future monitoring for E. coli/enterococci indicates the standard has not been exceeded, these monitoring data may be used to support delisting the water body from the 303(d) list. If a continuing problem is identified using E. coli/enterococci, the TMDL may be revised. 7.2 Implementation Plan Reductions for fecal coliform should be sought through identification and repair of aging sewer infrastructure as well as targeting other storm -driven sources. Enforcement of stormwater BMP requirements for construction sites, additional education related to farming practices and other land disturbing activities, and additional urban stormwater controls for sediment are potential management options for improving turbidity levels. For turbidity, much of the impairment is likely due to erosion from landuses during conversion from rural to urban uses. While stormwater controls are typically required during development activites, significant loadings can occur due to initial periods of land disturbance before controls are in place or during high rainfall periods during which the controls are inadequate. Additional turbidity impairment may be due to runoff from agricultural areas and from erosion of soils due to increased imperviousness in urbanizing areas. i• Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River The TMDL analysis was performed using the best data available to specify the fecal coliform and total suspended solids reductions necessary to achieve water quality criteria. The intent of meeting the criteria is to support the designated use classifications in the watershed. A detailed implementation plan is not included in this TMDL. The involvement of local governments and agencies will be needed in order to develop an implementation plan. 8. Public Participation A draft of the TMDL was public noticed in local newspapers --The Herald Sun (Durham County), The Times -News (Alamance County), The Stokes News (Stokes County), The Reidsville Review (Rockingham County), and News and Record (Guilford County). The public notice was announced through the papers on different dates starting from September 17, 2004 through September 20, 2004 (Appendix 11.5). The TMDL was also public noticed through DWQ web site at http://h2o.enr.state.nc.us/tmdl/TMDL list.htm#Draft TMDLs. A public comment period was through October 22, 2004. One written comment was received through email and is included in Appendix 11.6. The comment was carefully considered and the TMDL was revised accordingly. 9. Further Information Technical questions regarding this TMDL should be directed to the following members of the DWQ Modeling/TMDL Unit: Narayan Rajbhandari, Environmental Modeler,(narayan.rajbhandarikncmail.net), and Michelle Woolfolk, Supervisor (michelle.woolfolk@ncmail.net. Further information concerning North Carolina's TMDL program can be found on the Internet at the Division of Water Quality website: http://h2o.enr.state.nc.us/tmdl/General_TMDLs.htm. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 10. References Center for Watershed Protection. 1999. Microbes and Urban Watershed: Concentrations, Sources, and Pathways. Watershed Protection Techniques 3(1): 554:565. Cleland, B.R. 2002. TMDL Development from the "Bottom Up" — Part II: Using load duration curve to connect the pieces. Proceeding from the WEF National TMDL Science and Policy 2002 Conference. Division of Environmental Health (DEH). NCDENR. 2000. Report on the Proper Maintenance of Septic Tank Systems in Accordance with Section 13.5 of HB 1160 (Clean Water Act of 1999). http://www.deh.enr.state.nc.us/oww/Maintenance.PDF. March 15, 2000. Hyer, Kenneth, Doughlas Moyer, and Trisha Baldwin. 2001. Bacteria Source Tracking to Improve TMDL Development in Bacteria. U.S. Geological Survey, WRD, 1730 East Parham Rd., Richmond, VA 23228. In va.water.usgs.gov/GLOBAL/posters/BST.pdf. North Carolina Department of Agriculture and Consumer Services. http://www.ncagr.com/stats/cniysumm/ North Carolina Department of Environment and Natural Resources. 2003. Surface Waters and Wetlands Standards. Environmental Management Commission, Raleigh, NC. North Carolina Department of Environment and Natural Resources. 2003. North Carolina Quality Assessment and Impaired Waters List (2002 Integrated 305(b) and 303(d). Division of Water Quality, Water Quality Section, Environmental Sciences Branch, 1617 Mail Service Center, Raleigh, NC—27699-1617. Water North Carolina Department of Environment and Natural Resources. 2004. Total Maximum Daily Loads for Turbidity and Fecal Coliform for East Fork Deep River, North Carolina. Final Report, March 2004. North Carolina Department of Environment and Natural Resources. http://www.deh.enr.state.nc.us/oww/ Stiles, T.C. 2002. Incorporating Hydrology in Determining TMDL Endpoints and Allocations. Proceedings from the WEF National TMDL Science and Policy 2002 Conference. U.S. Census Bureau. http://quickfacts.census.gov/gfd/states/ U.S. Environmental Protection Agency (USEPA). 1991. Guidance for Water Quality -Based Decisions: The TMDL Process. Assessment and Watershed Protection Division, Washington, DC. U.S. Environmental Protection Agency (USEPA) 1998. Draft Final TMDL Federal Advisory Committee Report. U.S. Environmental Protection Agency, Federal Advisory Committee (FACA). Draft final TMDL Federal Advisory Committee Report. 4/28/98. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River U.S. Environmental Protection Agency (USEPA) 1999. Protocol for Developing Sediment TMDLs. First Edition. EPA 841-B-99-044. U.S. EPA, Office of Water, Washington D.C. U.S. Environmental Protection Agency (USEPA) 2000a. Revisions to the Water Quality Planning and Management Regulation and Revisions to the National Pollutant Discharge Elimination System Program in Support of Revisions to the Water Quality Planning and management Regulation; Final Rule. Fed. Reg. 65:43586-43670 (July 13, 2000). U.S.Environmental Protection Agency (USEPA) 2000b. Implementation Guidance for Ambient Water Quality Criteria for Bacteria — 1986. DRAFT. Office of Water. EPA-823-D-00-001. U.S. Environmental Protection Agency (USEPA) 2001. Protocol for DevelopingPthogen TMDLs. First Edition. EPA 841-R-00-002. U.S. EPA, Office of Water, Washington D.C. U. S. Geological Survey (USGS). 1999. Relation of Land Use to Streamflow and Water Qua at Selected Sites in the City of Charlotte and Mecklenburg County, North Carolina, 1993-98. Water Resources Investigations Report 99-4180, Raleigh, NC. Wayland, R. November 22, 2002. Memorandum from Rober Wayland of the U. S. Environmental Protection Agency to Water Division Directors. Subject: Establishing TMDL Waste Load Allocation for stormwater sources and NPDES permit requirements based on those allocations. :, Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River 11. APPENDICES Appendix 11.1. Water Quality Parameters Used for TMDL Development Appendix Table 11. IA. DWQ monitoring data of turbidity and flow in the Haw River at the ambient station B 1140000. Sampling Date Flow cfs Turbidity NTU Sampling Date Flow cfs Turbidity NTU Sampling Date Flow cfs Turbidity NTU 1/30/1997 680 31 2/22/2000 492 15 11/19/2002 2110 36 2/26/1997 453 12 3/21/2000 2210 35 12/12/2002 3200 70 3/26/1997 989 13 4/19/2000 15401 33 1/6/2003 835 21 4/28/1997 4790 65 5/31/2000 214 11 2/12/2003 535 14 5/27/1997 712 22 6/26/2000 384 6.2 3/11/2003 824 20 6/25/1997 185 12 7/25/2000 699 75 4/2/2003 1210 26 7/17/1997 202 8.8 8/24/2000 99 5.6 5/20/2003 862 45 8/26/1997 654 47 9/20/2000 1310 60 6/23/2003 492 13 9/16/1997 124 13 10/18/2000 126 4.4 7/21/2003 352 17 10/22/1997 222 29 11/30/2000 182 7.4 8/18/2003 2500 85 11/24/1997 511 60 12/14/2000 1451 6.7 9/11/2003 287 8.8 12/18/1997 238 2.2 1/31/2001 399 7.6 1/27/1998 2330 26 4/25/2001 295 3.7 2/14/1998 900 100 5/10/2001 136 3.7 3/24/1998 1210 39 6/19/2001 109 6.5 4/29/1998 584 13 7/26/2001 6801 40 5/26/1998 349 18 8/30/2001 116 9.8 6/25/1998 165 4.2 9/26/2001 195 37 7/27/1998 137 3.5 10/23/2001 59 8.9 8/24/1998 95 5.9 11/28/2001 89 17 9/29/1998 94 2.4 12/19/2001 2801 17 10/28/1998 69 2.1 1/30/2002 264 20 11/19/1998 97 2.2 2/6/2002 153 7.8 12/29/1998 259 14 3/13/2002 293 19 1/21/1999 520 45 4/3/2002 254 18 4/22/1999 202 5.3 5/8/2002 1061 11 7/19/1999 139 6.9 6/5/2002 76 6.8 8/16/1999 221 2.9 7/1/2002 67 6 9/29/1999 3980 65 8/5/2002 54 10 11/18/1999 171 2.9 9/5/2002 209 18 12/22/1999 899 16 10/3/20021 901 5.4 70 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.1 continued. Appendix Table 11.1B. DWQ monitoring data of total Suspended solids (TSS) and flow in the Haw River at the ambient station B 1140000. Sampling Date Flow cfs TSS m /L TSS Load (Tons/day) Sampling Date Flow cfs TSS m /L TSS Load Tons/day) 1/30/1997 680 12 21.95 1/21/1999 520 15 20.98 2/26/1997 453 2 2.44 4/22/1999 202 3 1.63 3/26/1997 989 12 31.92 7/19/1999 139 61 2.24 4/28/1997 4790 100 1288.51 8/16/1999 221 23 13.67 5/27/1997 712 42 80.44 9/29/1999 3980 78 835.08 6/25/1997 185 8 3.98 11/18/1999 171 1 0.46 7/17/1997 202 10 5.43 12/22/1999 899 16 38.69 8/26/1997 654 190 334.26 2/22/2000 492 10 13.23 9/16/1997 124 9 3.00 3/21/2000 2210 54 321.02 10/22/1997 222 8 4.78 4/19/2000 1540 35 144.99 11/24/1997 511 20 27.49 5/31/2000 214 9 5.18 12/18/1997 238 1 0.64 6/26/2000 384 7 7.23 1/27/1998 2330 14 87.75 10/18/2000 126 2 0.68 2/14/1998 900 86 208.21 1/31/2001 399 6 6.44 3/24/1998 1210 11 35.80 4/25/2001 295 8 6.35 4/29/1998 584 1 1.57 7/26/2001 680 60 109.75 5/26/199B 349 12 11.27 10/23/2001 59 5 0.79 6/25/1998 165 5 2.22 1/30/2002 264 8 5.68 7/27/1998 137 7 2.58 4/3/2002 254 9 6.15 8/24/1998 95 5 1.28 7/1/2002 67 6 1.08 9/29/199B 94 4 1.01 10/3/2002 90 3 0.73 10/28/1998 69 2 0.37 1/6/2003 835 8 17.97 11/19/1998 97 5 1.30 4/2/2003 1210 13 42.31 12/29/1998 259 7 4.88 7/21/2003 352 8 7.58 71 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.1 continued. Appendix Table 11.1C. DWQ monitoring data of fecal coliform and flow in the Haw River at the ambient station B 1140000. Sampling Date Flow Fecal Coliform #/100mL) Fecal Coliform (#/day) Sampling Date Flow Fecal Coliform #/100mL Fecal Coliform #/da Sampling Date Flow Fecal Coliform #/100mL Fecal Coliform #/da 1/30/1997 680 100 1.66E+12 2/22/2000 492 140 1.69E+12 6/18/2002 60 50 7.34E+10 2/26/1997 453 181 1.99E+11 3/21/2000 22101 3100 1.68E+14 6/25/20021 49 25 3.00E+10 3/26/1997 989 230 5.57E+12 4/19/2000 1540 760 2.86E+13 6/27/2002 59 1000 1.44E+12 4/28/1997 4790 910 1.07E+14 5/31/2000 214 260 1.36E+12 7/1/2002 67 1 1.64E+09 5/27/1997 712 400 6.97E+12 6/26/2000 384 6400 6.01E+13 7/2/2002 60 240 3.52E+11 6/25/19971 185 300 1.36E+12 7/25/2000 699 6400 1.09E+14 7/9/2002 491 31 3.72E+10 7/17/1997 202 2400 1.19E+13 8/24/2000 991 45 1.09E+11 8/5/2002 54 96 1.27E+11 8/26/1997 654 390 6.24E+12 9/20/2000 1310 3500 1.12E+14 9/5/2002 209 70 3.58E+11 9/16/1997 124 240 7.28E+11 10/18/2000 126 740 2.28E+12 10/3/2002 90 58 1.28E+11 10/22/1997 222 210 1.14E+12 11/30/2000 182 76 3.38E+11 11/19/20021 2110 230 1.19E+13 11/24/1997 511 460 5.75E+12 12/14/2000 145 64 2.27E+11 12/12/2002 3200 3800 2.98E+14 12/18/1997 238 300 1.75E+12 1/31/2001 3991 60 5.86E+11 1/6/2003 835 59 1.21E+12 1/27/1998 2330 200 1.14E+13 4/25/2001 295 470 3.39E+12 2/12/2003 535 39 5.10E+11 2/14/1998 900 2000 4.40E+13 5/10/2001 136 18 5.99E+10 3/11/2003 824 46 9.27E+11 3/24/1998 1210 90 2.66E+12 6/19/2001 109 40 1.07E+11 4/2/2003 12101 300 8.88E+12 4/29/1998 584 1401 2.00E+12 8/30/2001 116 34 9.65E+10 5/20/2003 862 970 2.05E+13 5/26/1998 349 790 6.75E+12 9/26/2001 1951 350 1.67E+12 6/23/2003 492 50 6.02E+11 6/25/1998 165 27 1.09E+11 10/23/2001 59 260 3.75E+11 7/21/2003 352 110 9.47E+11 7/27/1998 137 45 1.51E+11 11/28/2001 89 41 8.93E+10 8/18/2003 2500 8200 5.02E+14 8/24/1998 95 140 3.25E+11 1/30/2002 264 29 1.87E+11 9/11/2003 2871 120 8.43E+11 9/29/1998 94 5601 1.29E+12 2/6/2002 153 56 2.10E+11 10/28/1998 69 91 1.54E+11 3/13/2002 2931 60 4.30E+11 11/19/1998 97 10 2.37E+10 4/3/2002 254 360 2.24E+12 12/29/1998 259 640 4.06E+12 5/8/2002 106 73 1.89E+11 1/21/1999 520 64 8.14E+11 5/21/2002 92 51 1.15E+11 4/22/1999 202 361 1.78E+11 5/30/2002 75 530 9.73E+11 7/19/1999 139 36 1.22E+11 6/4/2002 861 63 1.33E+11 8/16/1999 221 180 9.73E+11 6/5/2002 76 53 9.85E+10 9/29/1999 3980 3600 3.51E+14 6/11/2002 66 44 7.10E+10 11/18/19991 171 600 2.51E+12 6/13/2002 67 52 8.52E+10 72 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.1 continued. Appendix Table 11.1D. DWQ monitoring data of fecal coliform and flow in the Deep River at the ambient station B4615000. Sampling Date Flow Fecal Coliform #/100mL) Fecal Coliform (#/day) Sampling Date Flow Fecal Coliform (#/100mL Fecal Coliform #/day) 1/23/1997 103 45 1.13E+11 2/23/2000 99 320 7.75E+11 2/25/1997 102 101 2.50E+10 3/30/2000 66 6401 1.03E+12 3/25/1997 102 62 1.55E+11 4/26/2000 71 120 2.08E+11 4/29/1997 4220 3500 3.61E+14 5/30/2000 30 81 5.95E+10 5/5/1997 222 640 3.48E+12 6/28/2000 93 73 1.66E+11 5/22/1997 45 72 7.93E+10 7/27/2000 53 320 4.15E+11 6/2/1997 62 2001 3.03E+11 8/16/2000 29 91 6.46E+10 6/26/1997 25 27 1.65E+10 9/26/2000 392 1800 1.73E+13 7/28/1997 25 10 6.12E+09 10/30/2000 30 18 1.32E+10 8/28/1997 16 140 5.48E+10 11/29/2000 36 63 5.55E+10 9/29/1997 31 91 6.90E+10 12/21/2000 34 960 7.99E+11 11/19/1997 28 451 3.08E+10 1/16/2001 26 120 7.63E+10 12/17/1997 27 14 9.25E+09 4/3/2001 288 1000 7.05E+12 1/26/1998 186 73 3.32E+11 5/22/2001 42 160 1.64E+11 2/23/1998 494 100 1.21E+12 6/25/2001 47 50 5.75E+10 3/16/1998 79 36 6.96E+10 7/17/2001 24 11 6.46E+09 4/22/1998 206 821 4.13E+11 9/17/2001 21 33 1.70E+10 5/20/1998 152 110 4.09E+11 10/4/2001 17 281 1.16E+10 6/17/1998 62 310 4.70E+11 1/17/2002 21 15 7.71E+09 7/16/1998 21 27 1.39E+10 2/12/2002 47 55 6.32E+10 8/18/1998 49 420 5.04E+11 3/21/2002 105 31 7.96E+10 9/9/1998 102 9801 2.45E+12 6/25/2002 16 26 1.02E+10 10/14/1998 20 110 5.38E+10 7/18/2002 17 40 1.66E+10 11/5/1998 20 20 9.79E+09 8/13/2002 14 10 3.43E+09 12/15/1998 53 260 3.37E+11 9/12/2002 16 46 1.80E+10 1/19/1999 260 54 3.44E+11 10/14/2002 722 2900 5.12E+13 3/17/1999 77 451 8.48E+10 11/20/2002 149 5200 1.90E+13 5/26/1999 24 18 1.06E+10 12/18/2002 107 150 3.93E+11 6/15/1999 19 24 1.12E+10 1/7/2003 117 770 2.20E+12 7/27/1999 32 82 6.42E+10 2/19/2003 248 510 3.09E+12 8/31/1999 42 330 3.39E+11 3/4/2003 241 260 1.53E+12 9/30/1999 939 6000 1.38E+14 4/1/2003 252 14000 8.63E+13 10/28/19991 32 80 6.26E+10 5/20/2003 153 180 6.74E+11 11/23/1999 34 81 6.74E+10 6/10/2003 374 1200 1.10E+13 12/28/1999 43 82 8.63E+10 7/15/2003 179 800 3.50E+12 8/12/2003 4751 41001 4.76E+13 9/22/2003 101 200 4.94E+11 73 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.1 continued. Appendix Table 11.1E. UCFRBA monitoring data of TSS, turbidity, and flow in the Third Fork Creek at the ambient station B30325000. Sampling Date Flow (cfs) cfs TSS m /L) Turbidity (NTU) TSS Load (ton/da Sampling Date Flow (cfs) cfs) TSS Turbidity (NTU)ton/da TSS Load 4/26/2000 14.84 23.00 21.00 0.92 8/7/2003 7.81 13.60 29.00 0.29 5/4/2000 10.93 39.00 40.00 1.15 9/25/2003 54.67 14.40 20.00 2.12 6/5/2000 7.50 98.001 89.00 1.98 7/6/2000 7.81 27.00 16.00 0.57 8/2/2000 83.57 48.00 110.00 10.79 9/6/2000 9.37 19.00 38.00 0.48 10/10/2000 4.06 6.00 3.60 0.07 11 /20/2000 7.65 11.001 16.00 0.23 12/5/2000 4.06 3.50 23.00 0.04 1/17/2001 17.18 3.00 14.70 0.14 2/15/2001 28.12 5.50 20.00 0.42 3/14/2001 10.15 7.00 15.00 0.19 4/5/2001 12.50 21.001 90.00 0.71 5/10/2001 3.83 12.50 17.00 0.13 6/14/2001 23.43 84.20 75.00 5.31 7/2/2001 3.83 16.60 33.00 0.17 8/1/2001 2.34 16.00 21.00 0.10 9/3/2001 8.59 17.501 12.00 0.40 10/2/2001 4.84 11.50 50.00 0.15 11 /1 /2001 5.70 18.50 6.80 0.28 12/13/2001 2.42 24.00 39.00 0.16 1 /2/2002 3.83 6.00 3.50 0.06 2/5/2002 8.59 2.701 14.00 0.06 3/5/2002 5.62 10.30 20.00 0.16 4/2/2002 15.62 37.00 45.00 1.55 5/2/2002 5.62 11.00 11.00 0.17 6/3/2002 2.97 25.00 16.00 0.20 7/1/2002 4.76 31.001 33.00 0.40 8/2/2002 3.75 7.80 14.00 0.08 9/2/2002 32.80 18.00 29.00 1.59 10/2/2002 5.15 3.20 8.10 0.04 11 /5/2002 11.72 3.80 13.00 0.12 12/10/2002 23.43 7.90 16.00 0.50 1 /6/2003 14.06 10.001 20.00 0.38 2/6/2003 13.28 9.60 22.00 0.34 3/10/2003 12.50 11.10 24.00 0.37 4/7/2003 97.63 168.00 130.00 44.12 5/7/2003 9.37 22.00 37.00 0.55 6/3/2003 12.50 14.00 28.00 0.47 7/9/2003 6.401 10.50 20.00 0.18 74 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.1 continued Appendix Table 11.1F. DWQ monitoring data of TSS, turbidity, and flow in the Dan River at the ambient station N2300000. Sampling Date Flow cfs TSS m /L Turbidity NTU TSS Load tons/da sampling Date Flow cfs TSS m /L) Turbidity (NTU) TSS Load (tons/da 2/20/1997 1440.00 7.00 11.00 27.12 1/25/1999 3210.00 110.00 120.00 949.84 3/20/1997 4640.00 64.00 70.00 798.82 4/20/1999 591.00 3.00 5.60 4.77 4/24/1997 3280.00 35.00 26.001 308.81 6/9/1999 418.00 8.00 5.601 9.00 5/28/1997 1210.00 8.00 7.90 26.04 7/28/1999 660.00 1.00 6.20 1.78 6/25/1997 939.00 15.00 10.00 37.89 8/25/1999 591.00 51.00 60.00 81.08 7/24/1997 1250.00 34.00 21.00 114.33 9/27/1999 279.00 26.00 28.00 19.51 8/21/1997 1090.00 43.50 26.00 127.55 10/21/1999 762.00 1.00 7.70 2.05 9/15/1997 846.00 53.00 26.001 120.61 11/8/1999 476.00 5.00 2.301 6.40 10/27/1997 736.00 14.00 11.00 27.72 2/29/2000 775.00 4.00 3.90 8.34 11/12/1997 595.00 1.00 2.60 1.60 3/22/2000 2610.00 52.00 50.00 365.09 1/6/1998 758.00 2.00 4.20 4.08 4/24/2000 845.00 13.00 9.30 29.55 1/22/1998 978.00 5.00 7.10 13.15 5/16/2000 516.00 8.00 4.40 11.10 2/19/1998 2580.00 53.00 50.001 367.83 6/15/2000 509.00 11.00 9.001 15.06 3/10/1998 4000.00 80.00 29.65 860.80 7/26/2000 354.00 4.00 5.60 3.81 4/28/1998 1310.00 11.00 9.30 38.76 8/29/2000 862.00 56.00 70.00 129.85 5/28/1998 1450.00 160.00 200.00 624.08 9/27/2000 1190.00 73.00 80.00 233.68 6/23/1998 750.00 10.00 9.10 20.18 12/11/2000 347.00 5.00 2.80 4.67 7/22/1998 500.00 17.00 14.001 22.87 6/21/2001 328.00 4.00 5.501 3.53 8/26/1998 451.00 9.00 13.00 10.92 9/13/2001 237.00 9.00 9.50 5.74 9/24/1998 414.00 4.00 5.30 4.45 12/18/2001 702 33.00 45.00 62.32 10/22/1998 329.00 4.00 4.50 3.54 3/4/2002 808 10.00 13.00 21.74 11/24/1998 383.00 5.00 4.30 5.15 6/4/2002 240 12.00 15.00 7.75 12/14/1998 2220.00I 160.00 120.001 955.49 9/17/2002 328 17.00 37.00 15.00 12/17/2002 1060 15.00 20.00 42.77 3/26/2003 1780 38.00 55.00 181.95 6/3/2003 1380 14.00 15.00 51.97 9/30/20031 1080 14.00 15.001 40.67 75 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.2. NPDES Permits Daily Fecal Watersheds Permit No. Name Facility Types NC County Receiving Water Body Flow Daily TSS Coliform —Facility MGD m /L #/100mL Pentecostal Holiness Discharging 100% Domestic < Haw River NC0046809 Church 1MGD Guilford Bena'a Creek 0.02 45 400 Quarterstone Farm Discharging 100% Domestic < Haw River NC0066966 WWTP 1MGD Guilford Buffalo Creek 0.16 45 400 Industrial Process & Commercial Wastewater Haw River NC0001384 Williamsburg plant Discharge Caswell Buttermilk Creek 0.025 45 400 Western Alamance Discharging 100% Domestic < Haw River NC0045144 High School 1MGD Alamance HAW RIVER 0.01 45 400 Western Alamance Discharging 100% Domestic < Haw River NC0031607 Middle School 1MGD Alamance HAW RIVER 0.015 45 400 Oak Ridge Military Discharging 100% Domestic < Haw River NC0046043 Academy 1MGD Guilford HAW RIVER 0.04 45 400 Altamahaw/Ossipee Discharging 100% Domestic < Haw River NC0045161 Elementary School 1MGD Alamance HAW RIVER 0.012 45 400 Discharging 100% Domestic < Haw River NC0046019 The Summit WWTP 1MGD Rockingham HAW RIVER 0.015 45 400 Williamsburg Discharging 100% Domestic < Haw River NC0066010 Elementary School 1MGD Rockingham HAW RIVER 0.004 45 400 Industrial Process & Altamahaw Division Commercial Wastewater Haw River NC0003913 plant Discharge Alamance HAW RIVER 0.15 108 400 Pleasant Ridge Discharging 100% Domestic < Haw River NC0065412 WWTP 1MGD Rockingham Little Troublesome Creek 0.0235 45 400 Willow Oak Mobile Discharging 100% Domestic < Haw River NC0060259 Home Park 1 MGD Rockingham Little Troublesome Creek 0.0175 135 400 Harvin Reaction Groundwater Remediafion Haw River NC0084778 Technology Discharge Guilford North Buffalo Creek 0.11 45 400 Guilford Correctional Discharging 100% Domestic < Haw River NC0029726 Center WWTP 1MGD Guilford North Buffalo Creek 0.025 45 400 Northeast Middle & Discharging 100% Domestic < Haw River NC0038156 Senior High WWTP 1MGD Guilford Reedy Fork 0.032 45 400 Autumn Forest Manuf. Home Discharging 100% Domestic < Haw River NC0022691 Community 1MGD Guilford Reedy Fork 0.082 45 400 Industrial Process & Monarch Hosiery Commercial Wastewater Haw River NC0001210 Mills Incorporated Discharge Alamance Reedy Fork 0.05 81.5 NA McLeansville Middle Discharging 100% Domestic < Haw River INCO038172 School WWTP 1MGD Guilford South Buffalo Creek 0.0113 45 1400 Shields Mobile Home Discharging 100% Domestic < Haw River NC0055271 Park 1MGD Alamance Travis Creek 0.006 45 400 Countryside Manor Discharging 100% Domestic < Haw River NC0073571 WWTP 1MGD Guilford Troublesome Creek 0.015 45 400 Southern Elementary Discharging 100% Domestic < Deep River NC0038091 School 1MGD Guilford Hickory Creek 0.0075 45 400 Southern Guilford Discharging 100% Domestic < Deep River NC0038229 High School 1MGD Guilford Hickory Creek 0.012 45 400 Crown Mobile Home Discharging 100% Domestic < Deep River NC0055255 Park 1MGD Guilford Hickory Creek 0.042 45 400 Plaza Mobile Home Discharging 100% Domestic < Deep River NC0041483 Park 1MGD Guilford Hickory Creek 0.003 45 400 Third Fork Brenntag Southeast, Groundwater Remediafion Creek NC0086827 Inc. Discharge Durham Third Fork Creek 0.0144 30 NA Cams Way Mobile Discharging 100% Domestic < Dan River NC0075027 Home Park 1 MGD Fors h Ader Creek 0.0432 45 400 Greystone Discharging 100% Domestic < Dan River NC0078115 Subdivision WWTP 1MGD Fors h Belews Creek 0.032 45 400 Rangecrest Road Discharging 100% Domestic < Dan River NC0083933 WWTP 1MGD Forsyth Belews Creek 0.06 45 400 76 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.2 continued Discharging 100% Domestic < Dan River NC0060461 Abington WWTP 1MGD Fors h Belews Creek 0.385 45 400 Creekside Manor Discharging 100% Domestic < Dan River NC0037311 Rest Home 1MGD Fors h Belews Creek 0.01 45 400 Briarwood Discharging 100% Domestic < Dan River NC0028746 Subdivision WWTP 1MGD Stokes Fork Creek 0.05 45 400 Horizons Residential Discharging 100% Domestic < —Brushy Dan River NC0056791 Care Ctr 1MGD Fors h Buffalo Creek 0.015 45 400 Kobewireland Industrial Process & Copper Products Commercial Wastewater Dan River NC0035173 Incorporated Discharge Stokes DAN RIVER 0.025 45 400 North Stokes High Discharging 100% Domestic < Dan River NC0044962 School 1MGD Stokes DAN RIVER 0.0115 45 400 Mikkola Downs Discharging 100% Domestic < Dan River INCO067091 WWTP 1MGD Forsyth East Belews Creek 0.072 45 400 Stokes Correctional Discharging 100% Domestic < Dan River NC0029777 Center WWTP 1MGD Stokes Flat Shoals Creek 0.0132 45 400 Quail Acres Mobile Discharging 100% Domestic < Dan River NC0059251 Home Park 1 MGD Rockingham Hogans Creek 0.018 45 400 Gold Hill Mobile Discharging 100% Domestic < Dan River NC0060542 Home Park 1 MGD Rockingham Hogans Creek 0.0176 45 400 Industrial Process & Britthaven Of Commercial Wastewater Dan River NC0044750 Madison Discharge Rockin am Hogans Creek 0.025 45 400 Bethany Elementary Discharging 100% Domestic < Dan River NC0037001 School 1MGD Rockingham Huffines Mill Creek 0.01 45 400 Industrial Process & JPS Elastomerics Commercial Wastewater Dan River NC0003441 Corp -Caro Plt Discharge Stokes Little Dan River 0.015 135 NA South Stokes High Discharging 100% Domestic < Dan River NC0044954 School 1 MGD Stokes Little Neatman Creek 0.0173 45 400 R.H. Johnson Discharging 100% Domestic < Dan River NC0079049 Construction WWTP 1MGD Forsyth Rough Fork 0.06 45 400 Twin Lakes Mobile Discharging 100% Domestic < Dan River NC0057720 Home Park 1MGD Stokes Timmons Creek 0.04 45 400 R J Reynolds Industrial Process & Tobacco Co - Brook Commercial Wastewater Voss Creek (Sandy Dan River NC0003492 Cove Discharge Stokes Branch) 0.02 45 400 Weekly Average Permitted Limits Municipal Wastewater Haw River NC0023868 Eastside WWTP Dischar e, Large Alamance HAW RIVER 12 45 400 GM Municipal Wastewater Haw River NC0024881 Reidsville WWTP Discharge, Large Rockingham HAW RIVER 7.5 45 400 GM North Buffalo Creek Municipal Wastewater Haw River NC0024325 WWTP Discharge, Large Guilford North Buffalo Creek 16 45 400 GM Municipal Wastewater Haw River NC0047384 T.Z. Osborne WWTP Discharge, Large Guilford South Buffalo Creek 40 45 400 GM Municipal Wastewater Deep River NC0024210 East Side WWTP Discharge, Large Guilford Richland Creek 26 45 400 GM Municipal Wastewater Dan River NC0021075 Madison WWTP Discharge, < 1MGD Rockingham DAN RIVER 0.775 45 400 GM Municipal Wastewater Dan River NC0082384 Danbury WWTP Discharge, < 1MGD Stokes DAN RIVER 0.1 45 400 GM Municipal Wastewater Dan River NC0028011 Stoneville WWTP Discharge, < 1MGD Rockingham Mayo River 0.25 45 400 GM Municipal Wastewater Dan River NC0021873 Ma odan WWTP Discharge, Large Rockingham Mayo River 4.5 45 400 GM Municipal Wastewater Dan River NC0025526 Walnut Cove WWTP Discharge, < 1MGD Stokes Town Fork Creek 0.5 45 400 GM Industrial Process & Belews Creek Steam Commercial Wastewater Dan River NC0024406 Station Discharge Stokes West Belews Creek 0.01 45 400 GM 77 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.3. Load Reduction Estimations Appendix Table 11.3A. Estimation of Load Reduction Required in turbidity (tons TSS / day) for the Haw River. Existing Load Allowable Load Percent Flow Exceeded TSS Load Percent Flow Exceeded TSS Load 15.00% 208.206 10.00% 104.5388 19.30% 80.44176 15.00% 74.90574 20.20% 109.752 20.00% 58.03137 21.20% 334.2594 25.00% 47.57749 Average 183.1648 71.26335 Load Reduction = 61% Note: Power curve estimation is not used for the data point violating the water quality criteria. Appendix Table 11.3B. Estimation of Load Reduction Required in fecal coliform (# / day) for the Haw River. %flow Exceeded Ilaowable Load (# / day) Est. Voilated Loads # / day) 10.000% 1.11858E+13 8.79488E+13 15.000% 8.01502E+12 4.51728E+13 20.000% 6.20944E+12 2.81564E+13 25.000% 5.09086E+12 1.95135E+13 30.000% 4.29817E+12 1.44619E+13 35.000% 3.74328E+12 1.12258E+13 40.000% 3.3117E+12 9.01415E+12 45.000% 2.92416E+12 7.42799E+12 50.000% 2.59828E+12 6.24716E+12 55.000% 2.30762E+12 5.34153E+12 60.000% 2.03458E+12 4.6299E+12 65.000% 1.79677E+12 4.0593E+12 70.000% 1.57658E+12 3.59389E+12 75.000% 1.39162E+12 3.2087E+12 80.000% 1.22427E+12 2.88584E+12 85.000% 1.05693E+12 2.61221 E+12 90.000% 8.80772E+11 2.37804E+12 95.000%1 6.69387E+1 11 2.17588E+12 Average I 3.35085E+12 1.44474E+13 Load Reduction = 77% Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.3 continued. Appendix Table 11.3C. Estimation of Load Reduction Required in fecal coliform (# / day) for the Deep River. % Flow Exceeded Fecal Load (#/day) Est. Exceeded Load #/day) 10.00% 2.14908E+12 1.82991 E+13 15.00% 1.56777E+12 8.26123E+12 20.00% 1.21547E+12 4.69883E+12 25.00% 9.95272E+11 3.03327E+12 30.00% 8.27926E+11 2.12131E+12 35.00% 7.04618E+11 1.56782E+12 40.00% 6.07733E+11 1.20656E+12 45.00% 5.28463E+11 9.57677E+11 50.00% 4.58001 E+11 7.78879E+11 55.00% 3.96347E+11 6.46075E+11 60.00% 3.34693E+11 5.44708E+11 65.00% 2.92416E+11 4.65567E+11 70.00% 2.55424E+11 4.02582E+11 75.00% 2.29001 E+11 3.51629E+11 80.00% 1.94E+11 3.0982E+11 85.00% 1.67E+11 2.75086E+11 90.00% 1.50E+11 2.45911 E+11 95.000% 1.15E+11 2.21168E+11 Average 6.21531 E+ 111 2.46596E+12 Load Reduction = 75% 79 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.3 continued. Appendix Table 11.3D. Estimation of Load Reduction Required in Turbidity (# TSS / day) for the Third Fork Creek. % Flow Exceeded TSS Load (ton/day) Est. Load Violated (ton/day) 10.00% 3.290173 8.010034 15.00% 1.864432 4.54532 20.00% 1.316069 3.04071 25.00% 1.041888 2.226143 30.00% 0.822543 1.725461 35.00% 0.712871 1.391085 40.00% 0.603198 1.154292 45.00% 0.542879 0.979118 50.00% 0.493526 0.845072 55.00% 0.444173 0.739693 60.00% 0.405788 0.655007 65.00% 0.367403 0.585692 70.00% 0.329017 0.528073 75.00% 0.301599 0.479539 80.00% 0.274181 0.438184 85.00% 0.246763 0.402591 90.00% 0.219345 0.371686 95.00%1 0.180961 0.344638 (Average 1 0.7476011 1.581241 Load Reduction = 53% :1 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.3 continued. Appendix Table 11.3E. Estimation of Load Reduction Required in Turbidity (# TSS / day) for the Dan River. % Flow Exceeded TSS Load (tons/day) Est. Load Violated (ton/day) 10.00% 229.8497 1369.863 15.00% 185.4728 743.4249 20.00% 160.4397 481.8418 25.00% 143.3716 344.209 30.00% 129.7172 261.4956 35.00% 118.3385 207.2759 40.00% 108.439 169.4852 45.00% 100.7015 141.9138 50.00% 92.96398 121.0737 55.00% 86.13676 104.8707 60.00% 79.6509 91.97967 65.00% 74.18912 81.52512 70.00% 68.38599 72.90818 75.00% 63.038 65.70671 80.00% 57.57622 59.6155 85.00% 52.00066 54.40903 90.00% 45.05965 49.91739 95.00%1 35.95669 46.01045 (Average 1 101.73821 248.1959 Load Reduction = 59% Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.4. Estimates of Relative Loadings for Point and Non -point Sources Appendix Table 11.4A. Estimates of TSS and Fecal Coliform Runoff Loading Rates for Urban and Rural Lands (USGS, 1999). Land Use Type TSS Conc tons/Sq. mi) FC Conc. mg/L Mixed forest/pasture/low density residential 2400 15 Mixed forest/pasture/medium & low density residential 21001 20 Mixed forest/pasture/medium & low density residential 5641 24.5 Rural Average 1688 20 1 Industrial 122 27.5 Industrial 300 14.6 Medium -density residential 225 29 Medium -density residential 77 26.5 High -density residential 1000 15 Developing 4700 13 Urban Average 1071 21 Appendix Table 11.413. Relative TSS Loading from Urban and Rural Areas. Watershed Land Use Land % Relative TSS Rate tons/sq mi/yr Normalized TSS Load Rates tons/sq mi/yr TSS Loading Ratio Haw River Rural 82.771 1688 1397.1576 88.33% MS4 17.23 1071 184.5333 11.67% Deep River Rural 73.41 1688 NA NA MS4 26.59 1071 NA NA Third Fork Creek Rural 40.84 1688 689.3792 52.11 % MS4 59.16 1071 633.6036 47.89% Dan River Rural 100 1688 1688 100.00% MS4 1 01 01 01 0 Note: TSS data estimated in Appendix Table 4A was utilized to estimate average sediment loading in stormwater runoff. The relative percent contributions of TSS were multiplied by the land use distribution and normalized to estimate the relative loading percentage for urban (MS4) and rural (non-MS4) areas. M. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.4 continued. Appendix Table 11.4C. Relative Fecal Coliform Concentration from Urban and Rural areas Watershed Land Use Land % Relative Fecal Rate Normalized Fecal Coliform Conc. Rates (mg/100mL) Fecal Coliform Conc. Ratio m /L Haw River Rural 82.77 20 16.554 82.06% MS4 17.23 21 3.6183 17.94% Deep River Rural 73.411 20 14.682 72.45% MS4 26.59 21 5.5839 27.55% Third Fork Creek Rural 40.84 20 NA NA MS4 59.16 21 NA NA Dan River Rural 100 20 NA NA MS4 0 0 NA NA Note: Fecal coliform data estimated in Appendix Table 4A was utilized to estimate average fecal coliform concentrations in stormwater runoff. The relative percent contributions of fecal coliform were multiplied by the land use distribution and normalized to estimate the relative loading ratio for urban (MS4) and rural (non-MS4) areas. :' Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.5. Public Notice The Herald Sun SLW of N011h ckt im (-)3CLLV aF QtAMn nwrr& umM.B. MLDMNogg sulk �Wofn UYN 11W dkisdw [AmdpdCkri of x,W. -ne uufbmu FiOW Gx, bx.., palaimkm of The &m IL cem-cpT r puI4Lbod in krd a ;umd rhrW ibhh 11 saidCmmy, and AA a njicji of 'Which UmLpBRedL atrueanp}•_ wLg pub IiaW Id mia nc-MAW Gm-- nm 1}c 206 dnk od 3eplerrJwff• 2OX SRtn W Md sukXnb9d bgfUM mr phis 18 d y of NOMTDbU, I. 7 41w NLm U � My n+xnnaieewn aqp m twT Lf� MA E Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.5 continued. The Times -News PWIC Nwam of NbrMGlr4n DMO- d M. N� ( m ■ drop. AFFIDAVIT OF M9FATTON OF ADVERTISf.4+lEN-I � The Timis-Nm publishing -Company I � �4 -WONW = SriWa HwroaVmN NC [�, da cxnif} � Iht ed�Rtu� nr � nr�l��4FsaoEs M M419 FAt* d PuGLLC Ibsla■ 9LM[i V Rm Lb t.e011M .%4rnwlir% 4t linesw h3 Tbu Mm:rNm ra-puhIiiiWa hLmmw,--, C--qvruk, R'orIIn[am NM in iuLr3 of 3MPkM�•; zy, MA 14VA1 M"AMr KAMM 5rpmtamAwhyihidqxruT;mFIhli X d•}ad�, _,2KW Tlhf�ppLmoaiu� -12zaL,. % L M. Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.5 continued. The Stokes News APVWA 'I O' P 11Al JC&M" ramuaa=k WpWW mcd aL� V bor ri afrar: sm, M--* •ram Ford W. � kekd hmm ray � i&.)r% dM3w ihi 6M � I•rt{I W. i Srrdaai�� -71HL" LI am {Rlbb b cm*br aMOMI Ed C rM6 wKbm.*of 'kIE(JhT AM Fa-W'SPAFW. WC, wood a & ;v lyda. dI M'"P ei brar%r u '_-FM S'.-01L5 www . PEN1 M..yreL. 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TMDi.Ed—A�Y r Mr R'�'FR{�:aF 6aq WM i 9db � W ] MGM &ZhK -dOLW M-T.aPaw*jbTmX 9WA4WMP4W224 ILL � y Wrnr,MMMftMOU04 Ck+ ffift am6w1ki r`tI'r*'t bu ne.r :1 Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.5 continued. The Reidsville Review #J_ EAKI aryl = ]AMMM rraIYJH 9FP`.ti; CMIPMV 17rimewM I dt--t: 1 fFria43 L h0LTM Uupi.:�M Zx:r:ppl Ciw I Trimary I r-LLK cn NIWi [PrLffmryE I JW 921P {Wlya yu 1700-16l7 Phmm LftimwA CUPP 733-MIS3 FCarL ftts (19f1911CIM 13s ap ore. I 0911 G01 Fi$l ra,klou : RM TILE "LOBVILLC MTvzrM CIAMA Bare 1 &111 Li ' ter•:jra Jib R&L" MAV- r dpg-Pe71 - J)AISY AA1i--L-&V3N-vv '-PM 1 33 URXP YOF w k1 G R Q%AL. i+ {Air7l l Zr I ur%kW a Ord r*rr l ! it ►4' •l r9r Illrr Gr gMw IMmrM(v. —.j tarir.Cr�. FGU if • rsr}�a� la rrv� ar} 7 W kL ■+f I RR rl4i} , rt'i �1fM�ll�0611 �FM9AfP� IIJ .1 8q 1h- in��Hl-m tltltltlrnnq n I'M�.�nc tCOMM �rQl c�ir.{.I, n#6sr• Appendix 11.5 continued. 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YaLa at requesW la r+iwlcw Ire TMD1 arid mMI yc_pr eflm- mMnle ID hic Dw PI m nma }llanohr alirA:, f_ Rvbpn mmliihwxr 1511 iwaU Sem@9 Celllfir iiblaMghr Nt 416'9!)-141 T. CUPI 8* Of the ilfla� may bs aG lal nod bT C&Ile Mi. Room M zkham a4 ALL. 5S6 or 6n hW In LeilLe I a "Vlf h7v.i nmaU-mtAVIm dill. Yffillain Ir4M+I EM I.s r i!I.- perdu Lht- TMDL Hill be an. C_8�lo LRII1 0Gt13d41-1 2.2, Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Appendix 11.6. Public Comments and DWQ Response Followings are the comments received from Mr. Steve Shoaf, City of Burlington, NC and the DWQ' s responses to the comments. The comments are in plain text and the responses are in italics. Comment 1. Page is The stream segment identified for the Haw River (19.2 miles) is very discrete. How was this segment determined when it is possible that the contributing pollutants are coming from an upstream section? The impaired segment in the Haw River from NC 87 to NC 40 was explicitly defined in the NC Water Quality Assessment and Impaired Waters List (2002 Integrated 305 (b) and 303(d) Report). The actual hydraulic length of the segment was approximately 13 miles. The 19.2 miles as estimated in the 303(d) list was incorrect. The actual distance is corrected in the final TMDL report. Comment 2. Page 3: The first bullet item identifies the segment of the Haw River that is impaired, but states that the segment is 13 miles. Is the distance correct? The distance is correct. Comment 3. Page 6: The paragraph below the definitions states that "Once EPA approves a TMDL, then the water body may be moved to Category 4a... Water bodies remain on Category 4a of the list until compliance with water quality standards is achieved." After compliance is achieved, is the TMDL designation removed or does it continue indefinitely? The TMDL designation can be removed for this pollutant after standard are achieved. The assessment unit may remain in category 4a if other TMDL apply. Comment 4. Page 12: In the third paragraph the report states "The DWQ conducted a special study in the Haw River... for a six -week period from 01/06/04 to 01/16/04." I assume that the dates run into February. Yes, the special study was conducted from 01106104 to 02116104. The study date is corrected in the final TMDL document. :' Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Comment 5. Page 13: The turbidity equation relating turbidity to flow has an R-square value of 0.66. At what point does DWQ consider the R-square to be too weak to show a causal relationship? The graph presented on this page looks like the data fits better than suggested by the formula. There is no fixed value that defines strength or weakness among variables. However, in theory, the correlation (relationship) between two variables is considered strong when their correlation (r) approaches to 1. In this study, the correlation between NTU and flow was 0.81 (r = Square Root of R-Square), which is high enough to justify a significant causal relationship between turbidity and flow for this study. The graph presented in Figure 1.7 shows the significant correlation. Comment 6. Page 14: The water quality standard for turbidity states, "...if turbidity exceeds these levels due to natural background conditions, the existing turbidity level cannot be increased." This implies that turbidity can exceed 50 NTU and not violate the water quality standard. The regulation also states that implementation of BMP's will be considered as compliance with the water quality standard (page 25 of the report). It is correct that turbidity could exceed 50 NTU under natural background conditions. In this study, however, the background turbidity level did not exceed 50 NTU. Largest part of TSS loads was below the targeted line during all flow conditions. It is also correct that according to 15A NCAC 02B.0211 (3) (K) implementation of BMP's would be considered as compliance with the water quality standard. Comment 7. Page 14: The water quality standard for fecal coliform states that violations of the standard are expected during rainfall events and "... this violation is expected to be caused by uncontrollable nonpoint source pollution..." This study assumes that uncontrollable non point source pollution would occur during heavy rainfall events. Therefore, the fecal coliform load during above 90`h percentile flow event was not considered in the TMDL estimation. Comment 8. Page 16: Based on the 2002 data, is it possible that there was one year or a series of rainfall events during the 1997 — 2003 period that is responsible for the bulk of the fecal coliform exceedances? The fecal coliform data for 2002 look very good. This TMDL was developed based on the instantaneous monthly measurements. The measurement suggested that the fecal coliform exceeded 400 counts / 100 ml in more than 20% of the sample examined during the study period. rl Turbidity and Fecal Coliform TMDL: Haw River, Deep River, Third Fork Creek, and Dan River Comment 9. Page 24: The summary of the NPDES permit conditions is incorrect. The TSS (45 mg/L) and Fecal Coliform limits (400 cfu/100 mL geometric mean) in the permits are weekly averages. There are no daily maximums in the NPDES permits for these parameters. There are daily maximums in the NPDES permits for these parameters. In general, privately own industries are permitted under daily maximum limit, whereas publicly own industries are permitted under weekly average limit. Daily Maximum limits are possible as the result of this TMDL. The summary tables of the NPDES permit in this study are revised accordingly. Comment 10. Page 28: The formula for the relationship of TSS and turbidity has an R-square of 0.57. Again, this is not a very strong correlation. The relationship is moderate, because correlation (r) is estimated at 0.75 (r = Square Root ofR- Square value). Therefore, the relationship between TSS and NTU can be justified for this study. Comment 11. Page 32: After converting turbidity NTU to TSS loading, there were no violations during typical and low flows. This suggests that some of the problem could be (is) related to natural, uncontrollable conditions during heavy rains. In this study, turbidity measurement during above 90`h percentile flow (high flow) period was not considered in order to exclude natural, uncontrollable conditions in the TMDL estimation. 31