fishing creek water quality study quality/surface...fishing cr. lwp area water quality study report...

Fishing Creek Water Quality Study

in support of

NC Ecosystem Enhancement Program

Local Watershed Plan Development

Final Report

October 31, 2007

Prepared by Division of Water Quality

Watershed Assessment Team

Fishing Cr. LWP Area Water Quality Study Report Prepared by NC DWQ, Watershed Assessment Team

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Acronyms AMS: Ambient Monitoring System BAU: Biological Assessment Unit BI: Biotic Index BIMS: Basinwide Information Management System BMP: Best Management Practices BOD: Biological Oxygen Demand DA: Drainage area DEM: Division of Environmental Management (now known as DWQ) DENR: Department of the Environment and Natural Resources DMR: Discharge Monitoring Report DO: Dissolved Oxygen DWQ: Division of Water Quality EEP: (NC) Ecosystem Enhancement Program EPA: Environmental Protection Agency GIS: Geographic Information System HUC: Hydrologic Unit Code ISU: Intensive Survey Unit LULC: Land Use/Land Cover LWP: Local Watershed Plan NCIBI: North Carolina Index of Biological Integrity NH3: Ammonia NLCD: National Land Cover Database NO2+NO3 (also NOx): Nitrate + nitrite NPDES: National Pollutant Discharge Elimination System NTU: Nephelometric Turbidity Units PQL: Practical Quantitation Limit QA/QC: Quality Assurance/Quality Control QAM: Quality Assurance Manual QAPP: Quality Assurance Project Plan RL: Reporting Limit RPD: Relative Percent Difference SOP: Standard Operating Procedures SU: Standard Units (pH) TKN: Total Kjeldahl Nitrogen TN: Total Nitrogen TP: Total Phosphorus TSS: Total Suspended Solids (aka total suspended residue) UT: Unnamed Tributary WAT: Watershed Assessment Team WET: Whole Effluent Toxicity WWTP: Wastewater Treatment Plant


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Table of Contents Executive Summary and Recommendations................................................................................................. 5 Introduction and Watershed Overview ......................................................................................................... 7

Introduction...................................................................................................................................... 7 LWP area overview and water quality concerns.............................................................................. 7 Land use/land cover ......................................................................................................................... 9

Study Design and Methods Overview ........................................................................................................ 11

Monitoring locations...................................................................................................................... 11 Water quality indicators and overview of sampling methods........................................................ 15 NC stream classifications and water quality standards .................................................................. 17 Other screening values................................................................................................................... 18 Data management and analysis ...................................................................................................... 18 Quality assurance and quality control (QA/QC)............................................................................ 19

Results, and Discussion .............................................................................................................................. 20

Results: Mean chemistries by catchment ....................................................................................... 20 Specific conductance ........................................................................................................ 21 Fecal coliform................................................................................................................... 21 Total nitrogen.................................................................................................................... 22 Total phosphorus............................................................................................................... 23 Total suspended residues ..................................................................................................24 Zinc ................................................................................................................................... 24

Results: Stormflow sampling......................................................................................................... 25 Results: Site-specific water quality issues and impacts ................................................................. 25

Jordan Creek ..................................................................................................................... 25 Coon Creek ....................................................................................................................... 27 Hachers Run...................................................................................................................... 31 Foundry Branch ................................................................................................................ 32 Fishing Creek.................................................................................................................... 34 Tar River ........................................................................................................................... 37 Sand Creek........................................................................................................................ 38 Gibbs Creek ...................................................................................................................... 39

Results: Land use, chemistry, and habitat assessment correlations ............................................... 40 References................................................................................................................................................... 45 Appendix 1: Land use by catchment in Fishing Cr. LWP watershed ......................................................... 47 Appendix 2: NC DWQ Ambient Monitoring System result summary, 1997-2006.................................... 48 Appendix 3: Mean chemistry values by catchment .................................................................................... 49 Appendix 4: Distributions of grab and composite samples by flow regime ............................................... 50 Appendix 5: Habitat assessment results...................................................................................................... 55 Appendix 6: Summary of DWQ biological community sampling results .................................................. 56 Appendix 7: Monitoring station summary sheets ....................................................................................... 58 Appendix 8: Percent land use for monitoring location subwatersheds ...................................................... 81 Appendix 9: Spearmans ρ analysis results .................................................................................................. 82


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Figures

Figure 1: Fishing Creek Local Watershed Planning Area ............................................................................ 8 Figure 2: Simplified Land use/Land cover in Fishing Cr LWP area .......................................................... 10 Figure 3: Fishing Cr. LWP study monitoring locations.............................................................................. 12 Figure 4: Specific conductance, mean by catchment .................................................................................. 21 Figure 5: Fecal coliform, geometric mean by catchment............................................................................ 22 Figure 6: Total nitrogen, mean by catchment ............................................................................................. 22 Figure 7: Total phosphorus, mean by catchment ........................................................................................ 23 Figure 8: Total suspended residue, mean by catchment ............................................................................. 24 Figure 9: Zinc, mean concentrations by catchment .................................................................................... 24 Figure 10: ISCO storm sample residue and turbidity results ..................................................................... 30 Figure 11: Oxford sanitary sewer lines ....................................................................................................... 33

Tables

Table 1: Land use (% of area) by catchment and for entire LWP area ......................................................... 9 Table 2: Monitoring locations..................................................................................................................... 13 Table 3: Chemical analyses, methods, reporting limits, and NC water quality standards .......................... 15 Table 4: NC water quality standards and action levels ............................................................................... 17 Table 5: Composite storm sample results for JC1522 ................................................................................ 27 Table 6: Significant correlations between Land Use and chemical and habitat parameters (in part). ........ 41 Table 7: Monitoring sites with highest total percent area of developed land use categories. ..................... 42 Table 8: Monitoring sites with highest total percent area of Grassland/Herbaceous and Pasture/Hay.......42 Table 9: Monitoring sites with highest total percent area of Forested land uses ........................................ 42 Table 10: "Anomalies" of correlation results.............................................................................................. 43


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Executive Summary and Recommendations The NC Ecosystem Enhancement Program (EEP) selected a 70 square mile area located primarily in Granville County for development of a Local Watershed Plan (LWP). The area included Fishing Cr.; its tributaries Coon Cr., Jordan Cr., Foundry Br., and Hachers Run; Gibbs Cr.; Sandy Cr.; and the mainstem Tar R. The area is collectively referred to as the Fishing Creek LWP area. To assist EEP planners with identifying areas with water quality concerns that may benefit most from restoration, rehabilitation, enhancement, or other management activities in the watershed, staff from the NC Division of Water Quality (DWQ) conducted chemical, physical, and biological monitoring in the LWP area. Biological results were previously reported via memoranda (NC DENR DWQ, 2006a; NC DENR DWQ, 2006c). The focus of this report is on providing summaries of chemical, physical, and habitat assessments and integrating this information with these previously reported data. Major water quality impacts identified in this study include:

• The developed area of Oxford seemed to be having significant impacts on Foundry Br. • The WWTP discharge to Fishing Cr. resulted in very elevated specific conductance, nutrients,

metals, and stressed benthic communities downstream. • Periodic elevated specific conductance and nutrient levels were found in the relatively

undeveloped upper Coon Cr. watershed. Possible cause(s) may be agricultural practices or an illicit discharge.

• Elevated levels of metals, residues, and turbidity were found in one storm sample collected on Jordan Cr. The source is unknown.

• Many of the streams in the LWP area were characterized by poor flow during the study period. This may have been due to a combination of dry weather, beaverdams, and local geology (Slate Belt and/or Triassic Basin streams), though a perched culvert was noted at one location on an unnamed tributary to Fishing Cr.

• Many of the streams exhibited incised banks and fairly homogenous sandy beds, in a variety of landscapes. This may be due to a number of factors, such as altered hydrology in urban areas, agricultural land uses, beaverdams (and their periodic removal), and silviculture. Some streams may actually be recovering from historic land uses, such as agriculture and silviculture.

• Exploration of data using correlations between land use, habitat, and chemistry data suggested that sites CC1609, GC1620, JC1522, and UTJC158BY may have had issues with habitat that were unexpected given the land use within their respective drainage areas.

Recommendations for further investigation:

• Examine the UT to Jordan Cr. near Webb High School as a possible candidate for a demonstration project, such as riparian buffer enhancement, stormwater controls, etc. Though the stream did not exhibit water quality issues that were more severe than other monitored streams in the LWP area, the proximity to the high school makes this an ideal site for a project with an educational component.

• Perform more detailed assessments of Foundry Br. to identify areas that may be candidates for restoration, enhancement, or other projects. Also recommend confirming the character and condition of the sewer lines in this area and determine if replacement of any damaged areas is likely to lead to improve instream fecal coliform levels.

• If resources are available, limited follow-up storm sampling may be warranted in Jordan Cr. (site JC1522) to identify a possible source for elevated metal concentrations.

• Evaluate the UT to Coon Cr. (site UTCC1518) and upper Fishing Cr. (site FC15) to determine if enhancement or restoration projects would assist with poor flow and/or habitat issues.


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• If resources are available, further investigation of the upper Coon Cr. (site CC1525) may be warranted to try to identify cause of elevated conductance and nutrients. If due to agricultural practices, evaluate whether additional agriculture BMPs would be helpful.

• Evaluate the perched culvert at site UTFC1616 to determine if replacement would enhance flow issues at this site.

• Repeat benthic macroinvertebrate sampling at two locations, if resources are available: o HR15: Sample during the normal 2008 sample season to confirm the Good-Fair

bioclassification found in the 2006 sampling. o FC1608: Sample in March 2008 for comparison to March 2006 results to determine if

water quality improvements have occurred in response to the Oxford WWTP upgrades completed in fall 2006.


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Introduction and Watershed Overview Introduction The North Carolina (NC) Ecosystem Enhancement Program (EEP) selects watersheds throughout the state for development of a Local Watershed Plan (LWP). The LWP is meant as a guide for future restoration, rehabilitation, enhancement, best management practices (BMPs), or other activities within the watershed that will provide functional uplift to the waters of the area. More information on EEP’s Local Watershed Planning initiative can be found at http://www.nceep.net/pages/planning.htm. EEP identified an area in the Oxford, NC area for development of a Local Watershed Plan (LWP). The subwatersheds that comprise this area, collectively termed the Fishing Cr. LWP Area in this report, include Fishing Cr., its tributaries (including Coon Cr., Hachers Run, and Jordan Cr.), Sand Cr., Gibbs Cr., and a portion of the Tar R. To facilitate LWP development by EEP, a characterization of the surface water within the watershed was conducted by staff in the NC Division of Water Quality (DWQ). Water quality data were collected by DWQ staff from the Watershed Assessment Team (WAT) and Biological Assessment Unit (BAU) between September 2005 and November 2006. Results from these data collections are summarized in this report. LWP area overview and water quality concerns The LWP area is in the upper portion of the Tar-Pamlico River Basin. It is located primarily within Granville County, NC with small portions in Vance and Franklin Counties. Figure 1 shows the entire LWP area and its 26 catchments (as delineated by EEP), the city of Oxford, and location of the sole National Pollutant Discharge Elimination System (NPDES) discharge. The entire watershed area is 69.7 square miles. The area is part of the USGS hydrologic cataloging unit 03020101 (NC subbasin TAR01), and includes the 14-digit HUCs 03020101020010, 03020101030020, and 03020101030010. Fishing Cr. and its tributaries Foundry Br. and Jordan Cr. drain the majority of the city of Oxford, including industrial facilities and an agriculture research station. A portion of Coon Cr. (also a tributary to Fishing Cr.) passes through less developed areas in the eastern portion of the city, with a sanitary sewer line running parallel to the stream for much of its length. Other subwatersheds in the LWP area drain relatively rural, undeveloped areas with majority of land use being forested, low-density residential, and agriculture (pasture as well as row crops). However, during field reconnaissance, signs of development were noted in several areas in the Gibbs Cr. and Sand Cr. drainages, and a large housing development is also being considered in the headwaters of the Coon Cr. drainage (Tommy Marrow, Oxford City Manager, personal communication). The majority of waters carry the NC stream classification of C (protected for aquatic life and secondary recreation). Exceptions include Hachers Run from its source to the Lake Devin dam (WS-II CA) and the Tar R. (WS-V). All waters in the watershed carry the supplemental classification of NSW (nutrient sensitive water), which carries additional regulatory requirements for agricultural and stormwater management practices. The only NPDES-permitted facility in the LWP area is the City of Oxford Wastewater Treatment Plant (WWTP) (permit NC0025054), which discharges to Fishing Cr. The WWTP has had significant compliance issues over the years, including numerous sanitary sewer overflows (SSO), exceedences of


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Figure 1: Fishing Creek Local Watershed Planning Area


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the permit limits for several parameters (including selenium and fecal coliform), and failures of their quarterly whole effluent toxicity (WET) testing. Recent facility, infrastructure, and pretreatment improvements have been made and the WWTP is showing a better record of compliance and fewer SSOs. Further facility improvements were being performed under a Special Order of Consent (SOC) during the study period, and were completed in September 2006, near the end of the study period. The NC Water Quality Assessment and Impaired Waters List (also known as the Integrated 305(b) and 303(d) Report) (NC DENR DWQ, 2006d) classifies Fishing Cr. as impaired from its source to the confluence with Coon Cr., based on biological data previously collected by DWQ. The lower section of Fishing Cr. (from Coon Cr. to the Tar R.) was also previously listed as impaired, but was removed from the 2006 list based on additional biological data collected in 2002 that showed improvements in the benthic macroinvertebrate community in this reach. More background information on water quality in the LWP watershed can be found in the Summary of Existing Water Quality Data (NC DENR DWQ, 2005), the most recent DWQ Tar-Pamlico Basin Assessment Report (NC DENR DWQ, 2001b) and Tar-Pamlico River Basinwide Water Quality Plan (NC DENR DWQ 2002). More information on stream classifications, use support, and impaired waters can be found at h2o.enr.state.nc.us/pb/index.html. Land use/land cover Land use can play a critical role in water quality, and can affect instream habitat. GIS land use/land cover data (NLCD 2001) were provided by EEP, and included an analysis of land use within the entire LWP area as well as individual catchments (Appendix 1). For this report, land use categories were further grouped into Developed, Forested, and Agriculture (see Appendix 1), with the remaining categories (Scrub, Barren, Open Water, Emergent herbaceous wetland, and Woody wetland) left untouched. These more general groupings made comparisons between catchments somewhat less cumbersome. Percentages for these broader categories within each catchment and for the entire LWP area are shown in Table 1, and spatial distributions are shown in Figure 2.

Table 1: Land use (% of area) by catchment and for entire LWP area

Catchment Size

(sq.

mi.)

Dev

elop

ed

Fore

sted

Agr

icul

ture

Scru

b

Bar

ren

Ope

n w

ater

Em

erge

nt h

erb.

w

etla

nd

Woo

dy

wet

land

1 2.6 7.4 56.8 28.1 5.9 0.0 0.4 0.0 1.5 2 2.1 6.5 37.3 47.7 5.1 0.6 2.1 0.0 0.8 3 2.0 4.8 45.2 47.0 1.5 0.1 1.3 0.0 0.2 4 1.9 6.1 66.8 25.1 0.9 0.2 0.6 0.0 0.2 5 2.7 8.5 61.0 27.8 1.0 0.2 0.4 0.1 1.2 6 1.6 5.4 68.5 23.5 2.5 0.0 0.1 0.0 0.1 7 2.3 15.8 46.3 33.7 2.5 0.7 1.0 0.1 0.0 8 2.9 39.1 32.5 27.5 0.4 0.0 0.5 0.0 0.0 9 2.3 17.3 61.5 15.7 1.5 0.0 0.5 0.0 3.4

10 1.8 8.8 29.1 52.6 0.2 0.0 9.0 0.0 0.3 11 3.5 66.0 19.3 13.8 0.5 0.0 0.5 0.0 0.0 12 1.4 36.8 42.5 17.7 3.0 0.0 0.0 0.0 0.0 13 1.5 23.0 52.1 22.2 1.9 0.1 0.2 0.0 0.6 14 2.8 30.0 49.5 15.1 1.5 0.0 0.0 0.0 3.9 15 2.6 11.0 54.0 29.6 3.2 0.1 0.3 0.1 1.8 16 1.6 12.8 55.5 26.3 4.3 0.0 0.7 0.0 0.3 17 2.5 5.0 57.3 29.9 2.5 0.4 0.2 0.0 4.7 18 5.2 5.6 54.9 34.6 1.9 0.0 0.3 0.0 2.6 19 1.1 3.4 68.2 27.9 0.6 0.0 0.0 0.0 0.0 20 4.3 3.6 72.3 21.2 2.1 0.0 0.3 0.1 0.3 21 3.1 3.6 56.0 35.4 3.7 0.4 0.9 0.0 0.1 22 2.9 1.5 77.9 16.3 4.2 0.0 0.1 0.0 0.0 23 1.6 3.5 77.3 16.6 2.3 0.2 0.0 0.0 0.0 24 3.4 5.6 61.6 30.2 1.8 0.1 0.4 0.0 0.3 25 6.3 3.3 72.9 18.9 3.1 0.3 0.4 0.1 1.1 26 3.7 2.3 74.2 15.4 2.7 0.1 0.0 0.0 5.1

Entire LWP area 69.8 12.6 56.8 26.2 2.4 0.1 0.7 0.0 1.3

http:h2o.enr.state.nc.us/pb/index.html


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Forested land use is the dominant category in the entire watershed (57%), followed by a significant percentage of Agriculture uses (26%) and Developed areas making up another 13%. Within individual catchments, Developed shows the widest range of values (1.5-66%), and Forested (19-78%) and Agriculture (14-53%) uses are found in significant percentages in all catchments.

Figure 2: Simplified Land use/Land cover in Fishing Cr LWP area


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Study Design and Methods Overview Monitoring locations Sampling locations were selected on the basis of land use, point and non-point source impacts, catchment exit points, and accessibility. Public access, such as bridge crossings, was generally required. Twenty-nine sites in the LWP area were selected for monitoring (Figure 3). An additional two sites were sampled as regional reference sites by BAU biologists. These were located outside of the LWP area, and are not discussed in this report. Chemical, physical, habitat, and biological data were collected in this study, though not all types of sampling were performed at each location. Data collections were dictated by the objective of monitoring at the sampling site, available staff resources, and total analytical budget. For example, nutrients, metals, and fecal coliform were generally all monitored in urban areas, as well as along much of Fishing Cr. due to the WWTP outfall. In Coon Cr., sedimentation was a major constituent of concern, so many of these sites focused on monitoring of residues and turbidity. Biological sampling, due to its significant requirements of time and expertise of field staff, was performed in just a few areas of concern. Benthic macroinvertebrate samples were collected from seven locations within the LWP area. Fish community samples were collected from five locations. Field measurements and habitat assessments were performed at nearly all locations. Monitoring locations are shown in Figure 3 and described in Table 2. Table 2 also indicates the type of data collections made at each location. More detailed site information (latitude, longitude, road name, stream class, etc.) is included in the site-specific summaries in Appendix 7. As mentioned above, two of the sites listed (Sandy Cr. and Shelton Cr.) are not located in the LWP area and were used to assist in interpreting findings from the sites within the LWP area (most of which had never been previously sampled). Results from these locations are minimally discussed in this report.


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Figure 3: Fishing Cr. LWP study monitoring locations


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Table 2: Monitoring locations C

atch

men

t

Station number Description Comment M

onth

ly c

hem

istry

Stor

m sa

mpl

es

Fiel

d m

easu

rem

ents

B

enth

os c

omm

unity

Fi

sh c

omm

unity

Hab

itat a

sses

smen

t

1 UTCC1518 UT to Coon Cr. at SR 1518 Cleared timber. Exit point of subwatershed. X X 2 UTCC1515 UT to Coon Cr. at SR 1515 Upstream reference for sewer line impacts. Exit point of

subwatershed. X X1 X X X X

3 CC1525 Coon Cr. at SR 1525 Agricultural use in headwaters; well buffered at this location. Exit point of subwatershed. X X

1 X X

4 CC1522 Coon Cr. at SR 1522 Sewer line. Exit point of subwatershed. X X 5 UTJC158BY UT to Jordan Cr. at US 158 bypass Exit point of subwatershed. X X 6 JC158BY Jordan Cr. at 158 bypass Exit point of subwatershed. X 8 JC1522 Jordan Cr. at SR 1522 Exit point of subwatershed. X1, 2 X X 9 CC158BUS Coon Cr. at US 158 Business Sewer line, easement very wide and poorly vegetated. Exit

point of subwatershed. X X1, 2 X X

10 HR1004 Hachers Run at SR 1004 Downstream of Lake Devin. Exit point of subwatershed. X X1 X 11 FB1646 Foundry Br. at SR 1646 NH3 found in screening study. Exit point of subwatershed. X X1 X X 12 FC15 Fishing Cr. at US 15 Exit point of subwatershed. X X 13 FB1607 Foundry Br. near SR 1607 Upstream of confluence with Fishing Cr. X 13 FB1649 Foundry Br. at SR 1649 Downstream of City of Oxford and I-85. X X1, 2 X X 13 FC1607U Fishing Cr. near SR 1607 Just upstream of WWTP outfall. X X1 X X X X 14 CC1606 Coon Cr. at SR 1606 Good riparian buffer but bank failures rampant, severe

sedimentation issues. Exit point of subwatershed. X X

15 HR15 Hachers Run at US 15 Exit point of subwatershed. X X 16 FC1607 Fishing Cr. at SR 1607 Below WWTP outfall. X X1 X X 16 HR1608U Hachers Run at SR 1608 Upstream of confluence with Fishing Cr. X 16 FC1608 Fishing Cr. at SR 1608 Just below confluence with Hachers Run X X 16 FC96 Fishing Cr. at NC 96 Signs of nutrient enrichment. Exit point of subwatershed. X X1 X X


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Table 2: Monitoring locations (cont.) C

atch

men

t

Station number Description Comment M

onth

ly c

hem

istry

Stor

m sa

mpl

es

Fiel

d m

easu

rem

ents

B

enth

os c

omm

unity

Fi

sh c

omm

unity

Hab

itat a

sses

smen

t

17 CC1609 Coon Cr. at SR 1609 Last road crossing on Coon Cr. before confluence with Fishing Cr. Exit point of subwatershed. X X

1 X X X X

18 FC1643 Fishing Cr. at SR 1643 Last road crossing on Fishing Cr. before confluence with Tar R. Historic data record for chemical, biological monitoring. Exit point of subwatershed.

X X1, 2 X X X X

19 UTFC1616 UT to Fishing Cr. at SR 1616 Forested pasture, stream is fenced. Exit point of subwatershed. X X

1 X X

20 TR1622 Tar R. at SR 1622 Downstream of confluence with Fishing Cr; chlorine smell evident. Exit point of subwatershed. X X

22 GC1620 Gibbs Cr. at SR 1620 Relatively undisturbed watershed but signs of development (subdivisions) in near future. Exit point of subwatershed. X X

1 X X X X

23 UTGC1620 UT to Gibbs Cr. upstream of SR 1620

Exit point of subwatershed. X X

24 SC1623N Sand Cr. at SR 1623, northern crossing

Relatively undisturbed watershed, though some agriculture. Exit point of subwatershed. X X

1 X X X

25 TR1101 Tar R. at SR 1101 (Vance Co.) Near exit point of LWP watershed X X1 X X -- OxfordEff Oxford WWTP effluent at outfall X -- SC1405 Sandy Cr. at SR 1405 Regional reference site for benthos, located in Nash Co. X X X X -- SC158 Shelton Cr. at US 158 Regional reference site for fish community X

1 Storm samples taken as grab samples 2 Storm samples taken as composite samples over a 45-minute time period using an automated sampler (ISCO)


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Water quality indicators and overview of sampling methods Depending on the sampling location, a combination of any or all of the following monitoring methods were performed: chemical/physical sampling (baseflow and/or stormflow); habitat assessment; benthic macroinvertebrate community sampling; fish community sampling.

Chemical/ physical sampling and analysis Field measurements included temperature (°C), dissolved oxygen (mg/L and % saturation), specific conductance (µS/cm at 25°C), pH (S.U.), and occasionally turbidity (NTU). Measurements were taken using either a Hydrolab Quanta for all parameters (including turbidity), or a combination of a YSI 85 (for temperature, oxygen, and conductance) and a Fisher Accumet 61 (pH). All measurements were made in situ in a representative point of the channel that was well-mixed and flowing, generally at or near the thalweg. Meter calibration and measurements were performed in accordance with the NC DWQ Intensive Survey Unit (ISU) Standard Operating Procedures (SOP) (NC DENR DWQ, 2003a). Samples for chemical analysis varied between sampling locations, depending on the monitoring objective for that site and event. All samples were taken in accordance with ISU SOP and preserved, handled, preserved, and analyzed in accordance with DWQ Laboratory Section requirements outlined in their Sample Submission Guidance (h2o.enr.state.nc.us/lab/qa/sampsubguide.htm) and Quality Assurance Manual (NC DENR DWQ, 2003b). Parameters measured are shown in Table 3, along with the analytical method and reporting limit (Practical Quantitation Limit, or PQL). Most chemistry samples, including all monthly samples as well as one set of storm samples, were collected as grab samples by direct fill of sample bottles by immersion. At four locations, ISCO automated storm samplers were also used. These were programmed to take composite samples during storm events after a six-inch rise in stage. Composite samples were collected as 4 subsamples: the first taken immediately upon triggering and the remaining three at 15-minute intervals.

Table 3: Chemical analyses, methods, reporting limits, and NC water quality standards

Parameter EPA method Reporting limit Fecal coliform 600/8-78-017 1 colony/ 100mL Turbidity 180.1 1 NTU Susp. residues 160.2, 160.4 2.5 mg/L MBAS (detergents) 425.1 0.1 mg/L Organic carbon 415.1 5 mg/L Nutrients NH3 as N 350.1, 350.2 0.02 mg/L NO2+NO3 as N 353.2 0.02 mg/L TKN as N 350.1, 351.2 0.20 mg/L Total P 365.1 0.02 mg/L Metals Aluminum (Al) 200.7/200.8 50 µg/L Antimony (Sb) 200.8 10 µg/L Arsenic (As) 200.8 /200.9 5 µg/L Barium (Ba) 200.7 10 µg/L Beryllium (Be) 200.8/200.7 10 µg/L Cadmium (Cd) 200.8 /200.9 2.0 µg/L Calcium (Ca) 200.7 0.10 mg/L Chromium (Cr) 200.8 /200.7 25 µg/L Cobalt (Co) 200.8/200.7 50 µg/L Copper (Cu) 200.8 /200.9 2.0 µg/L Iron (Fe) 200.7 50 µg/L Lead (Pb) 200.8 /200.9 10 µg/L Lithium (Li) 200.7 25 µg/L Magnesium (Mg) 200.7 0.10 mg/L Manganese (Mn) 200.8/200.7 10 µg/L Mercury (Hg) 245.1 0.2 µg/L Nickel (Ni) 200.8 /200.9 10 µg/L Potassium (K) 200.7 0.10 mg/L Selenium (Se) 200.8/200.9 5.0 µg/L Silver (Ag) 200.8/200.9 5.0 µg/L Sodium (Na) 200.7 0.10 mg/L Thallium (Tl) 200.8 10 µg/L Zinc (Zn) 200.8 /200.7 10 µg/L Field measurements Dissolved oxygen -- 0.1 mg/L pH -- 0.1 S.U. Spec. conductance -- 1 µS/cm at 25°C Water temperature -- 0.1°C


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The composite samples would be retrieved as soon as practical (48 hours since the last measurable rain event. In addition to the automated storm samplers described above, a single set of grab samples was collected under stormflow (defined as the rising limb of the hydrograph) at all analytical chemistry sampling locations. One other set of chemistry samples were collected under “other” flow regime, i.e., measurable rain had fallen with the previous 48 hours but was not raining at the time of collection.

Biological community sampling Sampling, identification, and interpretation of results for benthic macroinvertebrate communities was performed by DWQ Biological Assessment Unit (BAU) biologists with support from WAT staff members in accordance with BAU Standard Operating Procedures For Benthic Macroinvertebrates (NC DENR DWQ 2003c). Sites were sampled by either Full Scale of Qual4 methods, depending on the size of the watershed. Since samples were taken in the winter, seasonality corrections (primarily for winter stonefly species) were made in accordance with SOP. Piedmont criteria were used in assigning all bioclassifications. Fish community sampling was performed by BAU biologists in accordance with the BAU SOP for Stream Fish Community Assessment and Fish Tissue (NC DWQ 2001a). Criteria for Outer Piedmont streams were used for calculation of the final NCIBI.

Habitat assessments Habitat assessments were made using the standard BAU form, included in the Benthic Macroinvertebrate SOP (NC DENR DWQ, 2003c). Assessments were made concurrently with benthos sampling by BAU staff. Trained WAT staff performed assessments at remaining monitoring locations in the LWP area.

GIS and other remote sensing data The majority of GIS data used in this report, such as land use/land cover, were compiled by WK Dickson for EEP and provided to WAT staff as an ESRI ArcGIS geodatabase. Georeferencing of monitoring locations was performed by WAT field staff using a recreational grade handheld GPS unit.

Precipitation Precipitation data used in this report were acquired from the Weather Underground website (www.wunderground.com), which provides real-time and historic weather data collected at airports and personal weather stations. Generally, the data used were collected at the Henderson-Oxford Airport (KHNZ), which is located in the northeastern portion of the LWP area (latitude, longitude: 36.3614, -78.5292).

http://www.wunderground.com/


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NC stream classifications and water quality standards North Carolina has a set of regulations that outline minimum water quality standards for the waters of the state. These standards may be narrative, but more commonly are numerical criteria (e.g., maximum allowable instream concentrations). For certain constituents (such as copper, iron, silver, and zinc), firm numerical standards are not in place as actual toxicity to aquatic organisms can vary dependent on additional factors, such as water hardness. In these cases the numerical criteria are referred to as action levels. Standards and action levels vary in accordance with the specified use of the waterbody in question. Certain uses, such as primary recreation or water supplies, require more stringent standards than others, such as aquatic life support. The uses of a waterbody are designated by a stream classification assigned by DWQ. The state has inventoried the waters of the state, assigned a unique identifier (“index number”) to each reach, and assigned it a stream classification. In the LWP area, almost all waters are classified as “C” class waters, which designates that they must be of sufficient quality to support aquatic life survival and reproduction, wildlife, secondary recreation, and agriculture. Exceptions include Hachers Run, which is classified as WS-II CA from its source to the Lake Devin dam, and the Tar R., which is classified as WS-V. These “WS” classifications protect these waters for use as a public water supply in addition to the C class uses. In addition to these primary classifications, all waters in the LWP area have the secondary classification of NSW (nutrient sensitive waters). The designation of “NSW” does not have additional numerical criteria associated with it, but instead requires best management practices, riparian buffers, etc. within the watershed to reduce nutrient inputs to surface water in the Tar-Pamlico River basin. Numerical standards and action levels for each applicable stream classification are shown in Table 4. These will be used throughout the report as screening values to identify areas that may have water quality

Table 4: NC water quality standards and action levels

Parameter Class C a Classes WS-II and WS-V a

Fecal coliform (GM = geometric mean)

GM


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concerns and perhaps could be considered higher priority watersheds for further study during LWP development. Other screening values In addition to water quality standards, it is often helpful to have an idea of “typical” results for chemical parameters, particularly since most parameters do not have associated standards or action levels. One source for these is the DWQ Ambient Monitoring System (AMS), a long-term chemical monitoring program that has been in existence since the 1960s, and currently consists of 339 locations that are sampled monthly for a suite of constituents. Data are readily available from the EPA Modernized STORET system via their website (www.epa.gov/storet). All available data collected by the AMS in the Upper Tar USGS Cataloging Unit (03020101) from 1997-2006 were extracted from STORET and distributions calculated for each parameter. Results are presented in Appendix 2, and these will be referred to as “typical” values for the Upper Tar. For biological communities, the NC DWQ has developed systems for rating streams based on the community composition found. The details of these biotic indices are described fully in the BAU SOPs (NC DENR DWQ, 2003c; NC DENR DWQ, 2001a). The most common values for the final bioclassification of piedmont streams are Poor, Fair, Good-Fair, Good, and Excellent (small watersheds may be rated Not Impaired or Not Rated). The DWQ uses these bioclassifications as part of their determination of use support during basin planning activities. Generally, ratings of Poor or Fair indicate that significant stressors on the community are present, which indicates impairment of aquatic life uses of the waterbody. This, however, is a simplification of use support methods by DWQ as presented in the North Carolina Water Quality Assessment and Impaired Waters List (NC DENR DWQ, 2006d). Determination of use support is beyond the scope of this report, but this information is useful for identification of areas where benthos or fish community data show stressed communities. Data management and analysis Chemistry and field data entered into a Microsoft Access database managed by WAT staff. This database was also used for managing station information, such as site descriptions and latitudes and longitudes. Data were retrieved, reviewed for completeness and possible errors or outliers, and duplicate results from QC samples were averaged before analysis. The majority of the statistical summaries and analyses were performed using SAS JMP 7.0 software (SAS, 2007). Analyses included summary statistics (means, medians, quartiles, etc.); examinations of distributions to determine normality; graphical exploration of data by site, subwatershed, and catchment as time series and/or distributions; correlations between parameters such as chemistry results, land use, and habitat metrics; and determination of statistically significant differences between sites, subwatersheds, and catchments. Nonparametric methods were used whenever possible due to the overall lack of normality in data distributions. Results reported as less than the reporting limit (considered “non-detects” [NDs] for the purposes of this report) were analyzed using the value of the reporting limit, i.e., a “worst-case” scenario. Biological data were warehoused in a 4D database housed and managed by BAU. Results were calculated in accordance with the appropriate BAU SOP and were reported via memorandum (NC DENR DWQ, 2006a) to WAT and EEP staff. Habitat assessment data were stored in an Excel spreadsheet prepared by WAT staff. This was also imported in JMP for analyses that included correlations with chemistry and land use data.

http://www.epa.gov/storet


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Quality assurance and quality control (QA/QC) QA/QC requirements of this project included:

• Duplicate samples: Duplicate samples for chemical analysis were collected at a minimum of 10% of sites each day of sampling. This is part of a longer-term project of WAT to quantify the total variability due to environmental factors, sampling procedures, sample handling, and laboratory handling and analysis. No acceptance or rejection criteria were set for relative percent differences (RPDs) of duplicate samples, as this project is still ongoing.

• Equipment blanks: This only applies to dissolved fractions, since no additional sample collection equipment were used for total fractions (i.e., sample bottles are direct dipped). Equipment blanks consist of processing analyte-free distilled water as if it were environmental (surface water) sample. They were performed at the beginning and end of each day when sampling for dissolved fractions occurred. If blanks were reported with levels at or greater than the PQL, results from accompanying environmental samples were discarded.

• Overlap of 10% of sites for habitat assessments: Habitat assessments were made by BAU and WAT staff on different dates but at the same sites in several instances. This overlap was meant to provide some sense of the variability between the assessments conducted by each program as well as differences due to temporal/seasonal issues.

• Biological sample QC methods: These are described in the appropriate BAU SOPs. Samples collected as part of this project are part of the larger annual QA program maintained by each program.


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Results, and Discussion For LWP development, it is important to look at the watershed as a whole in order to prioritize catchments for further investigations. For example, chemistry results may be presented using maps that allow the reader to quickly identify possible problem areas. Statistical analyses, such as correlations, can show relationships (though not causality) between seemingly disparate parameters, which may also help identify useful secondary indicators as catchment prioritization proceeds. However, as with any data summarization, useful site-specific information may be masked, and this smaller-scale information should be addressed as well. For these reasons, results are presented in several different ways in this section: by catchment, subwatershed, and site. The focus of this report is on providing summaries of the chemical, physical, and habitat data collected, as it has not been previously summarized, and integrating it with previously reported biological data. More detailed information for each type of data collected is provided in the Appendices, or is available in previous reports. For example, biological community results were previously reported via memoranda (NC DENR DWQ, 2006a; NC DENR DWQ, 2006c).

Results: Mean chemistries by catchment ArcGIS was used to prepare color-coded maps, presented below, to easily identify catchments with unusual water quality results,. Means (or geometric means, in the case of fecal coliform) were calculated from all grab sample results and field measurements from each catchment (with the exclusion of results from the WWTP effluent). All available grab samples were included, with the majority from baseflow (i.e., >48 hours since last measurable rain) sampling events. Each sampling location also included a single set of stormflow (i.e., sampling during a rising hydrograph) and a single set of “other” flow (i.e., neither baseflow nor stormflow) samples. A table of the means for each of the water quality indicators addressed in this section is included in Appendix 3. Catchments were color-coded in the following maps based on these mean values to allow for easy identification of possible problem areas. Means, as opposed to medians, were used to capture whether or not sites were prone to much higher values during storm events; these are areas that may benefit for stormwater BMP retrofits, etc. Where appropriate, screening values are provided. These may be based on NC water quality standards or action levels, or historic water quality data collected in the Upper Tar hydrologic unit. These screening values are more fully described in the previous Study Design and Methods Overview section and in Appendix 2. Results presented are limited to parameters with notable results. For example, dissolved oxygen levels within the entire LWP watershed were generally in acceptable ranges (exceptions will be discussed in the site-specific descriptions), and these are not shown.


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Specific conductance One of the quickest measurements of water quality that can be performed is specific conductance, which indirectly measures the amount of disassociated ions (e.g., salts) in the water column. Past studies by WAT staff have found specific conductance to be one of the measurements most reliably correlated with benthic community health. Historic AMS data from the Upper Tar cataloging unit show a mean value of 102 µS/cm at 25°C (see Appendix 2). These mean value of conductance from all sites within a catchment are presented in Figure 4. In piedmont streams, values under 100 µS/cm at 25°C can be considered minimally impacted, based on historic AMS data. The range of 120-150 can be considered slightly elevated. Readings over 150 should raise concerns over water quality. The majority of the LWP area is


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the geometric mean from AMS data collected throughout the Upper Tar cataloging unit over the last ten years was 85 colonies/100mL. Geometric means by catchment are depicted in Figure 5. As would be expected, bacteria concentrations are elevated throughout the area in and around the city of Oxford in Foundry Br. and Fishing Cr. (catchments 11, 13, and 16). Means are also elevated in lower Coon Cr. (catchment 17) and the UT to lower Fishing Cr. (catchment 19). This UT drains an undeveloped area, and the elevation may likely be due to the monitoring site’s location in an active pasture. Background levels in relatively unimpacted areas (such as Gibbs Cr.) were slightly elevated (as compared to the AMS geometric mean of 85), possibly due to widespread beaver populations, as well as other wildlife, within the LWP area. Total nitrogen NC does not have numerical nutrient criteria at this time. Setting such criteria is difficult, as similar levels of nutrients in different types of systems may or may not produce similar instream ecological responses. Responses such as overgrowth of macrophytes or algal blooms due to enrichment can lead to mass die-off, which will increase biological oxygen demand (BOD), which in turn leads to possibly deleterious depressed oxygen levels as the organic material is broken down by microorganisms. Algal and periphyton overgrowths can also affect instream pH levels, as was seen at site FC96 during this study. Nutrient enrichment can also cause shifts in benthic communities; for example, increases in periphyton can lead to an increase in herbivore/scraper taxa. Mean total nitrogen was calculated by adding mean TKN and mean NO2+NO3 for each catchment. The mean for historic AMS data was similarly calculated and was 0.82 mg/L. Results for the LWP area are shown in Figure 6. Ranges used to classify catchments in the figure are not based on any numerical criteria; the intent of the figure is to indicate where total nitrogen values are higher or lower as compared to other catchments in the LWP area. However, it is

Figure 5: Fecal coliform, geometric mean by catchment

Figure 6: Total nitrogen, mean by catchment


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suggested that catchments with means over 1.0 mg/L could be considered higher priority areas for projects that may reduce nitrogen inputs. Catchment 16, in particular, shows a mean total nitrogen of 3.28 mg/L, due to extremely elevated values below the WWTP outfall. As will be discussed later in the site-specific results section, instream indicators of nutrient enrichment are seen downstream of this location. Catchment 3, as with specific conductance, also shows unexpectedly elevated nitrogen levels. The upper Foundry Br. watershed (catchment 11) also shows somewhat elevated levels. Total phosphorus In lake and estuary systems, phosphorus is generally considered a limiting nutrient, though this is not necessarily the case in flowing streams. Phosphorus concentrations throughout the state’s waterbodies have dropped significantly since the phosphate detergent ban was put in place in 1988 (Childress, 1997). Common sources of phosphorus are now mainly limited to fertilizers and organic materials, such as sewage. Similar to nitrogen, total phosphorus plays a role in overgrowth of algae and plants within surface water, and has some of the same issues as total nitrogen, i.e., not all systems react similarly to a given concentration. Phosphorus does not currently have numerical criteria associated with it. In the absence of a standard or action level, the mean from AMS data within the cataloging unit (0.08 mg/L) is provided as a rough screening tool. Mean total phosphorus results for each catchment are shown in Figure 7. The ranges of values are somewhat arbitrarily assigned and are only meant to provide a general ranking of catchments. Similar to other parameters discussed previously, catchments 16 (Fishing Cr. below the outfall) and 3 (upper Coon Cr.) show the highest mean values. The lower end of Coon Cr. (catchment 17) also shows higher concentrations as compared to other monitored catchments. Without data from catchments 4, 9, and 14 it is difficult to determine if the slight elevation of phosphorus in catchment 17 reflects a “recovery” from the higher values found in the headwaters or if there may be localized phosphorus sources in or near this catchment.

Figure 7: Total phosphorus, mean by catchment


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Total suspended residues Total suspended residue is a measure of the non-filterable solids (both organic and inorganic) suspended in the water column. NC does not have numerical criteria in either C or WS class waters. The mean value from AMS data from the Upper Tar was 15 mg/L. Mean total suspended residues were generally very low throughout the LWP area (Figure 8). Differences between catchments were fairly slight. Highest values were seen in Foundry Br., the most urbanized stream in the study, and in Fishing Cr. below the WWTP outfall. The Coon Cr. headwaters (catchment 3) showed comparatively slight elevations. Sand Cr., a relatively unimpacted subwatershed (catchment 24), also showed relatively higher concentrations. Though this stream seems physically and chemically to be a reference-type area, sedimentation and siltation have been an issue noted here. Zinc Zinc is commonly seen in urban areas. There is an existing action level of 50 µg/L to protect for aquatic life, as zinc can be toxic. The mean AMS zinc concentrations in the Upper Tar cataloging unit was 20 µg/L. Metals were only sampled at a handful of locations, and means for these catchments are shown in Figure 9. Concentrations were high in the urbanized Foundry Br. watershed (catchment 11). A relatively rural/undeveloped catchment shows slightly elevated results as compared to others in the LWP area: catchment 4 (upper Coon Cr.). The highest concentrations were found in Fishing Cr. below the WWTP outfall (mean = 97 µg/L). Some of the zinc loading may be coming from Foundry Br., but a significant percentage is coming from the effluent. The WWTP is required to monitor zinc in their effluent, but DWQ has not assigned a numerical limit in their NPDES permit. A likely cause may be the high number of industrial customers of the WWTP. Perhaps further pretreatment can be encouraged by either DWQ or the facility to assist in lowering zinc levels.

Figure 8: Total suspended residue, mean by catchment

Figure 9: Zinc, mean concentrations by catchment

Figure 7: Mean total suspended residue concentrations by catchment


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Results: Stormflow sampling Automated samplers (ISCO™ model 6712) were deployed for collection of composite samples during storm events at four monitoring sites in the watershed: CC158BUS (Coon Cr. at NC 158 business), FB1649 (Foundry Br. at SR 1649, New Commerce Dr.), FC1643 (Fishing Cr. at SR 1643, Eaton Rd.), JC1522 (Jordan Cr. at SR 1522, Salem Rd.). ISCO samples were also attempted at UTCC1515 (UT to Coon Cr. at SR 1515, Horner Siding Rd.), but the stream hydrology at this location was such that the rise in stage needed to trigger the automated sampler did not occur during storm events. Samples were analyzed for fecal coliform, nutrients, suspended residues (aka total suspended solids, or TSS), turbidity, and a suite of approximately 19 metals. All results for arsenic, beryllium, cadmium, chromium, cobalt, lithium, mercury, nickel, selenium, and silver were reported as non-detects, and so results for these metals are not presented. Distributions of the results from these composite samples are presented in Appendix 4. Results from all available grab samples taken at these five locations under different flow regimes are shown for comparison. As would be expected, the majority of parameters show a large increase in concentrations during storm events as compared to baseflow. More detailed graphs and discussions are presented on a site-specific basis in the next section where appropriate.

Results: Site-specific water quality issues and impacts Due to the large amount and diversity of available data within the watershed, results are organized in this section by subwatershed to assist with integration of findings from all sources. The subwatersheds used are Jordan Cr., Coon Cr., Hachers Run, Foundry Br., Fishing Cr., Tar R., Sand Cr., and Gibbs Cr. Chemistry results were analyzed by WAT. Other findings were obtained from reports by Wetland Program Development Unit Staff (NC DENR DWQ, 2006c), BAU staff (NC DENR DWQ, 2006a), and the Catena Group (Catena Group, Inc., 2005). Some GIS data were provided by WK Dickson and EEP. More detailed summaries of data from individual monitoring locations are presented in the following appendices:

• Appendix 1: Land use by catchment in Fishing Cr. LWP watershed • Appendix 4: Distributions of grab and composite samples by flow regime • Appendix 5: Habitat assessment results • Appendix 6: Summary of DWQ biological community sampling results • Appendix 7: Chemical monitoring station summary sheets

Jordan Creek The headwaters of the Jordan Cr. subwatershed lie in the relatively undeveloped area north and northwest of Oxford. It passes through low to moderately Developed areas, including commercial and residential, before flowing into Coon Cr. It flows through catchments 5, 6, 8 and 9. Catchments 5 and 6 are predominantly Forested with low amounts of Developed areas. Catchment 7 also has moderate amounts of Forested area, but Developed areas make up 16% of land area. Catchments 5, 6, and 7 have large areas that are identified as “Highly Erodible Soils” in the GIS data supplied by WK Dickson. Catchment 8 is one of the more highly developed catchments in the LWP area, though it is clustered mainly in the southern and western parts of the catchment. Moderate amounts of Pasture are found throughout all of these catchments.


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Data were collected by DWQ at three locations in the Jordan Cr. subwatershed: UTJC158BY (Unnamed Tributary [UT] to Jordan Cr. at US 158 bypass), JC158BY (Jordan Cr. near US 158 bypass), and JC1522 (Jordan Cr. at SR 1522, Salem Road). Field measurements and habitat assessments were performed at all locations, though they were discontinued at JC158BY early on in the study due to site accessibility issues. Limited baseflow analytical chemistry data were collected at JC1522 and an automated storm sampler (ISCO) was installed at this location, primarily to assess metal and sediment inputs from Jordan Cr. to Coon Cr. during stormflow. Several locations in the Jordan Cr. subwatershed were included in the mussel survey performed by the Catena Group, including reaches at or near JC1522 and UTJC158BY. Jordan Cr. was determined to be potentially suitable for mussel recruitment. UTJC158BY was located upstream of the US 158 bypass at a footbridge on Webb High School near the exit point of catchment 5. The stream was small (


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iron, lead, manganese, zinc, ammonia, TKN, residues, and turbidity. Aluminum, iron, and manganese are usually attributed to suspended soils, which may have been the case here, given the extremely elevated suspended residue and turbidity. However, the levels of lead were surprising, as detectable levels are rarely found in NC streams: less than 2% of lead analyses for the DWQ AMS program statewide showed reportable levels between January 1997 and September 2005. The results from storm samples collected on September 28 were fairly typical of storm flow. Rainfall rates during the August 30 storm were not unusual and were less than seen during the September 28 sampling. Similarly collected samples on the same date from a location located downstream (CC158BUS, discussed below) did not show these high levels. An overflow of the sanitary sewer adjacent to the stream was suspected, but none was reported by Oxford on that date and coliform and ammonia levels were lower than typically found in sewage. Further investigation of the area upstream of the ISCO installation was conducted to try to identify a possible source for the elevated chemistry results. These included additional baseflow samples and walking limited sections of the stream and a tributary. Samples were taken at three locations on Jordan Cr. and from a small unnamed tributary whose confluence with Jordan Cr. was just upstream of SR 1522. The only parameter showing any differences between sites on Jordan Cr. was copper: while the result was less than the reporting limit at the most upstream site (near the Masonic Home for Children), reportable levels were found upstream of SR1522 (3.4 µg/L) and at the ISCO sampling site (2.0 µg/L; at the reporting limit). No reportable levels were found for cadmium, chromium, nickel, lead, or zinc at any of these locations, and aluminum, iron, and manganese concentrations were unremarkable. There may have been a slight increase in NO2+NO3 at these two lower sites. The small tributary (DA ~1 sq. mi.) to Jordan Cr. that is located just upstream of SR 1522 runs behind a house with a number of junked cars and heavy machinery in the floodplain. This could be a source of metals if they had been flooded during the August storm event, though this is unlikely given the moderate rainfall rate and duration. Follow up samples showed reportable levels only for iron and manganese in the tributary. NH3, TKN, and total P levels were low. However, what appears to be a significant decrease in NO2+NO3 was noted when comparing results from upstream and downstream on the UT (0.31 mg/L upstream, 0.14 mg/L at mouth). Further investigation may be indicated in this catchment to try to identify this potentially significant, though periodic, pollutant source. Coon Creek The headwaters of Coon Cr. (catchment 3) and the unnamed tributary (UT) monitored in this study (catchments 1 and 2) are north and northeast of Oxford. Land use was dominated by moderate to high

Table 5: Composite storm sample results for JC1522

Date of storm event Analysis 08/30/2006 09/28/2006 Total precipitation for storm 0.62” 1.2” Aluminum total (µg/L) 6650 1200 Calcium total (mg/L) 14 10.5 Copper total (µg/L) 29 10.5 Fecal coliform (col/100mL) 4000 2000 Iron total (µg/L) 13,000 2500 Lead total (µg/L) 35.5


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Agriculture and moderate Forested land use. The confluence of the two streams occurs in catchment 4, which had high Forested and moderate Agriculture use, and from there Coon Cr. flows south through the eastern edge of Oxford with moderately to highly Developed land use (catchments 9 and 14). A sanitary sewer line easement runs along much of Coon Cr. in this section; in the past it has had an issue with overflows but has been replaced in recent years. Coon Cr. continues through catchment 17, which had land use similar to that found in the headwaters. The confluence with Fishing Cr. occurs in catchment 18 south of Oxford. Seven monitoring locations were located in the Coon Cr. subwatershed. Two were located on the unnamed tributary that drains catchments 1 and 2: UTCC1518 (UT at SR 1518, Winding Oak Rd.) and UTCC1515 (UT at SR 1515, Horner Siding Rd.). The remaining five were located on the mainstem: CC1525 (Coon Cr. at SR 1525, Perry Rd.), CC1522 (Coon Cr. at SR 1522, Salem Rd.), CC1606 (Coon Cr. at SR 1606, Antioch Rd.), CC1609 (Coon Cr. at SR 1609, Harris Rd.), and CC158BUS (Coon Cr. at US 158 Business). Field measurements and habitat assessments were collected from all locations. Analytical chemistry samples were collected monthly at UTCC1515, CC1525, CC1609, and CC158BUS. Composite storm samples were collected at CC158BUS and CC1609 using automated ISCO samplers. Benthos and fish community sampling occurred at two locations: UTCC1515 and CC1609. The Catena Group conducted mussel surveys at five locations at or near these sampling sites: UTCC1518 (referred to as Upper Coon Cr. in their report), CC1522, CC1606 (in two different reaches: one upstream and one downstream of the bridge crossing), and CC1609. Field measurements (pH, DO, specific conductance, and water temperature) did not show much variation between sites in Coon Cr. and so will be minimally discussed in the site-specific discussions below. Mean pH values were neutral (7.0 SU) to slightly basic (7.5 SU). Mean dissolved oxygen concentrations were well above the NC water quality standard of 4.0 mg/L, though some low values were seen at almost all of the monitoring locations in this subwatershed due to poor flow. Flow issues were common at almost all sites, particularly during summer months. Beaverdams were fairly prevalent throughout the Coon Cr. subwatershed, as in the rest of the LWP area, and may contribute to flow issues. However, many of the streams were incised, likely channelized in the past, had predominantly sand substrates with few riffles or pools, all of which may lend themselves to poor flow and re-aeration. UTCC1518 had particularly severe issues with flow; it had no visible flow during the majority of site visits. Instream habitat issues common in this subwatershed, as described above, were reflected in the low habitat assessment score of 46. The majority of points were lost in the categories Bottom Substrate (scored 4 out of 15 due to sand substrate and embeddedness), Pools (0 out of 10), Riffles (2 out of 10), and Bank Stability (6 out of 14 due to active bank erosion and poor quality riparian vegetation). The UT at the sampling site had a narrow buffer and much of the upstream area appeared to be fairly recently harvested (


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is reflected in the Excellent bioclassification assigned based on the BAU benthic macroinvertebrate sample. Fish community sampling resulted in a Good bioclassification, but BAU staff noted that no intolerant species were found. BAU staff noted an abundance of silt in some pools, though total suspended residues at this location were fairly low, even during storm flow (maximum = 16 mg/L). BAU and WAT staff both noted fairly prevalent periphyton growth in this stream. Nutrient levels were fairly low though a somewhat elevated value for NO2+NO3 (0.22 mg/L) was reported for June during baseflow conditions, indicating that there may be periodic nutrient inputs, possibly due to lawn/crop fertilization or other agricultural activities upstream. CC1525 (catchment 3) showed slightly elevated specific conductance values (mean=131 µS/cm at 25°C) as compared to other subwatershed sites, and periodically showed extremely elevated levels (maximum = 319 µS/cm at 25°C). This site had unexpectedly high values for a number of different parameters, including nutrients and TSS in addition to conductance, given the visible surrounding land use, which was extensive, intact, and primarily deciduous forest. This site was initially intended as a “least-impacted” site based on theses observations. Apparent “reference”-type conditions were also suggested by the high habitat assessment score of 90. This catchment had one of the highest percentages of Agriculture use. Its neighbor, catchment 2, had an equivalent percentage of Agriculture but did not show the same elevated levels of conductance or nutrients. Another unusual observation noted at CC1525 was the periodic appearance of a surface foam. A sample for Methylene Blue Active Substances (MBAS) was positive, indicating that detergents were present. This combined with elevated nutrients and relatively low fecal coliform levels might normally suggest the presence of a greywater discharge upstream, though no residences or other possible source were seen. Further investigations into this catchment may be warranted: the elevated parameters may be due to a significant localized pollutant source (such as an illicit discharge), or due to agricultural practices, in which case additional agricultural BMPs may be helpful. CC1522 was located near the exit point of the catchment 4, and Forested land use increased, Agricultural uses decreased, and Developed areas continued to be low as compared to upstream. Unlike the upstream site CC1525, instream habitat had some significant issues, and only received a score of 50. Bank Stability was poor, mid-channel bars were common, banks were very incised (some areas >3m high), and Pools were infrequent and homogenous in size (indicating that the stream may be filling in). Little area appropriate for benthos or fish colonization was available, riffles were rare and short, and though there was a good mix of materials in the substrate, embeddedness was moderate to high (40-80%). The left bank had a narrow riparian buffer (2m in most areas, >3m common), eroding sandy banks, mid-channel bar formation, shallow depth, poor quality habitat, high embeddedness (>50%) in riffles, and poor flow. No biological sampling was conducted at this location, though during field visits WAT staff found a number of mussels (Elliptio spp.). The sanitary sewer line easement was very wide and poorly vegetated in sections, particularly a steep slope behind a subdivision upstream of the road. A very small wetland area had developed between a small tributary and the road, but dried up in the summer shortly after the easement was mown as part of required maintenance. Suspended residues were relatively low in grab samples (total suspended residues maximum = 15 mg/L), which included one storm sample. Turbidity was surprisingly low, with a median value of 14 and a maximum of 39 NTU. An automated ISCO sampler was installed at CC158BUS for collection of composite storm samples. Suspended residue and turbidity results were still fairly low, even as compared to other composite storm


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samples collected (Figure 10). One composite storm sample analyzed for turbidity had a result over the water quality standard of 50 NTU, though this was one of the lowest recorded from all storm samples (Figure 10). Metals were also generally lowest at CC158BUS, as compared to other composite storm sampling sites. This location had the minimum and maximum fecal coliform levels from all storm samples.

CC1606 was located at the exit point of the next downstream catchment, (14), and passed through a highly Developed area in eastern Oxford, including I-85. Distributions of field measurements were nearly identical to those from CC158BUS, though without the occasionally depressed oxygen levels. This site actually showed DO saturations slightly above 100%, indicating possible supersaturation due to algal or macrophyte activity. The total habitat score was identical to CC158BUS, though the riparian buffer scored higher at CC1606 since it was wide and intact. The same issues seen upstream, such as mid-channel bar formation (extensive at this location), incised (~2m) and eroding banks, embeddedness, etc., were also noted. The GIS data that were supplied by WK Dickson indicated that there were large deposits of erodible soils in the catchment, particularly on the eastern side of the creek. The Catena Group sampled two separate reaches near this site and determined that it was “Potentially Suitable” for mussel recruitment, though mussels were more commonly found in the reach downstream of the road. CC1609 was the furthest downstream site sampled on Coon Cr. Land use in catchment 17 was predominantly Forested, with moderate Agriculture, and one of the relatively highest percentages of Woody Wetland of all LWP area catchments. Field measurements from CC1609 were on par with other Coon Cr. locations. High values as compared to the rest of the subwatershed were seen for copper (maximum = 16 µg/L) and fecal coliform (maximum=2100 col/100mL); a single high value for NH3 (0.20 mg/L) was also recorded at this location. The creek did not show much improvement in terms of habitat as compared to upstream sites, and received scores of 58 and 53 from BAU and WAT staff, respectively, with similar issues noted in terms of substrate and lack of available habitat. Though banks were definitely incised, at high flows the stream may almost have reasonable access to its floodplain, which was wooded and fairly intact. Flow, as with other locations on Coon Cr., could be poor on occasion. Benthos and fish sampling both resulted in a bioclassification of Good. The BI and EPT abundance at this location was nearly identical to that found in Gibbs Cr. (discussed below), an undeveloped watershed that may be appropriate as a “least-impacted” site for the LWP area. It should be noted that Gibbs Cr. showed similar habitat issues as Coon Cr., though not to the same extreme, and may suggest that the issues in Coon Cr. may be typical for the area, and possibly due to a combination of underlying geology (such as Slate Belt or Triassic Basin characteristics), historic impacts such as agriculture or silviculture, and current impacts such as beaverdams and Developed land use.

Figure 10: ISCO storm sample residue and turbidity results

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Hachers Run Hachers Run flows through catchments 10, 15, and 16. Its predominant land uses were Forested and Pasture. Data were collected at three locations: HR1004 (Hachers Run at SR 1004, Butner Rd); HR15 (Hachers Run at NC 15), and at HR1608U (Hachers Run at mouth, upstream of SR 1608,Fielding Knott Rd). Field measurements were regularly collected at HR1004 and HR15. Monthly grab samples were collected only at HR1004. Additional information collected at HR15 included habitat assessment, benthic macroinvertebrate sampling (done by other Wetland Program Development Unit staff as part of an EPA-funded grant), and a mussel survey by the Catena Group. Very limited data were collected at HR1608U, and were primarily a response to issues noted downstream in Fishing Cr. HR1004 was sampled above a public swimming pool (a drain from the public swimming pool is located in the floodplain) and the inactive Oxford water treatment plant. The sampling point was located upstream of the exit point for the catchment and was just over a half mile below the dam at Lake Devin, Oxford’s previous water supply. Land use in the catchment was dominated by Pasture (41%) with Deciduous, Evergreen, and Mixed Forest making up another 29%. This catchment also had one of the highest percentages of Cultivated Crop use. In the sampled reach, immediately surrounding land use was predominantly open/mown pasture, though no livestock were ever noted. The stream meandered back and forth along the fenced property line, and one side of the stream had a small, poor quality buffer along much of it. The stream was very small at this location (


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A single reading was below the screening value of 4.0mg/L. Benthic macroinvertebrate data results showed a relatively high BI of 6.70 and a bioclassification of Fair, though the sample was one EPT taxa short of receiving a classification of Good-Fair. Low flow was attributed as the possible cause of the stressed benthic community, which was supported by the relatively low percentage of filter feeders found. Re-sampling of this site for benthos in the future is warranted to confirm the bioclassification. The habitat assessment at this location resulted in a score of 78. Major issues were not seen with most of the metrics, with the exception of Bank Stability, which received a score of only 6 out of 14. HR1608U, located near the mouth of Hachers Run, was not an ongoing monitoring location, but field measurements were taken several times and nutrient and fecal coliform samples taken in May 2007 in an effort to identify sources of nutrient and bacteria peaks downstream in Fishing Cr. This location had very low flow from the mouth that continued several hundred meters upstream, perhaps backing up due to low flow in Fishing Cr. Its width was 4-5 meters with incised but relatively stable banks with a height of approximately two meters. Bedrock was noted in this section of the stream, providing grade control and appeared to facilitate ponding/backwaters. This location was also included in the mussel survey performed by the Catena Group. No mussels were found, and Hachers Run was deemed Physically Unsuitable for Recruitment, largely due to sedimentation issues. Foundry Branch The Foundry Br. headwaters are northwest of downtown Oxford and the stream runs through the middle of the city (catchments 11 and 13). It is crossed by Interstate 85 on the southern side of Oxford. Catchment 11 had the highest percentages of Developed land use in the LWP area, though the majority was Low Intensity and Open Space. It also had the lowest percentage of Forested and Agriculture land uses. The downstream catchment 13 showed a relatively high percentage of Developed land use, though significantly less that catchment 11. It also showed increases in Forested and Agriculture land uses, slightly below the median levels for all catchments. Data were collected at three locations: FB1646 (Foundry Br. at SR 1646, Oxford Loop, just upstream of I-85), FB1649 (Foundry Br. at SR 1649, New Commerce Dr., just downstream of I-85), and FB1607 (Foundry Br. near SR 1607, Knott’s Grove Rd., just upstream of the confluence with Fishing Cr.). FB1646 was selected as the most upstream sampling location as it was the first road crossing where the stream exhibited any flow, though it was low and spotty throughout the study. The site was below the downtown area and though there was a wooded buffer along the stream a large strip shopping center was very nearby. Field measurements indicated elevated specific conductance (median = 182 µS/cm at 25°C) but no issues were noted with DO or pH. Reportable levels of copper and zinc were seen in 71% and 57% of samples, respectively, which is common in urban streams. NO2+NO3 and total P appeared to be elevated in comparison to other sampling locations in the LWP area. Fecal coliform levels were elevated, having the second highest median (300 col/100mL) at baseflow of all sampling locations. The bacteria levels found at this location, as well as downstream at FB1649, are not uncommon in urban areas and are often due to sources such as wildlife, domestic pets, and failing sanitary sewer pipes. In reviewing the GIS layer of the sanitary sewers in Oxford (provided by WK Dickson), there are a number of sections that parallel or cross Foundry Branch that are made of vitrified clay and date back to the early 20th century (Figure 11). The City of Oxford may want to consider examining these sections for deterioration and determine if replacement is appropriate. Median residue and turbidity levels at baseflow were surprisingly low at this location given the upstream urban area. Even when samples taken under “Storm” and “Other” flow regimes are included, total suspended residue had a median value of 7.3 mg/L and turbidity of 8.3 NTU. However, high values are


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seen when looking at storm flow only: maximum total suspended residue was 45 mg/L and maximum turbidity was 98 NTU, which is well above the state water quality standard of 50 NTU. Though no significant issues besides elevated conductance and coliform concentrations were seen in chemistry data from FB1646, the stream was significantly degraded when examining habitat assessment results. WAT staff gave a total score of 48 to this site, the third lowest score of all locations rated, indicating severe impacts on instream habitat. Though it received high scores based on its lack of channel modification, its sinuosity, and good canopy, the homogenous sandy substrate led to habitat smothering, infrequent small riffles, and infill of pools. Bank stability was also an issue, likely due more to storm hydrology and upstream riparian buffer issues rather than the buffer immediately at the sampling location. Further reconnaissance of upstream areas would be useful to determine if there are possible areas suitable for stormwater BMP retrofits in this subwatershed to assist with sedimentation and hydrology issues. FB1649 was located about a quarter mile downstream, just below where Foundry Branch is crossed by I-85. The immediate area was much more extensively wooded, including the area between I-85 and SR 1649. This site was selected for comparison with FB1646 to see what additional impact a major interstate may have on this urban stream. Wilcoxon rank sum tests were run for each analytical chemistry and field parameter and included samples taken under baseflow, storm flow, and “other” flow conditions. A significant difference was only found for manganese, with the median concentration being lower at FB1649. This site is therefore being considered essentially the same as FB1646 for all other chemical and physical parameters. The habitat score at FB1649 was 54, essentially equivalent to upstream. However, at this downstream location there is some heterogeneity to the substrate: gravel and cobble are present along with sand. Embeddedness is still moderately high. A wider variety of habitat types were common and pool variety was better. Small riffles, low flow, and bank instability were the issues noted here, similar to FB1646. FB1607 Minimal data were collected at this location on Foundry Br. This site had excellent flow with a substrate that was a relatively good mix of cobble, boulder, gravel, and sand. It did not show the sedimentation and preponderance of sand seen in the upstream sites. No issues were seen with DO and pH was fairly neutral (median = 6.9 SU). Specific conductance was elevated, with a median of 157 µS/cm at 25°C. A single turbidity measurement was taken in the field after a week of heavy rains, which yielded a very high result of 92 NTU.

Figure 11: Oxford sanitary sewer lines


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Fishing Creek The headwaters of Fishing Cr. are located on the west side of Oxford, in a moderately Developed area. It flows south and is crossed by I-85, where land use shifted to a predominance of low-density Development and Agriculture. Foundry Br. joins it just south of the city, immediately above the outfall for the Oxford wastewater treatment plant (WWTP). Coon Cr. and Hachers Run also drain to Fishing Cr. Catchments included in this subwatershed are 12, 13, 16, 18, and 20. One unnamed tributary (UT) that drains catchment 19 and flows directly into Fishing Cr. is also included in this discussion. This UT drained predominantly Forested and Pasture areas. The Fishing Cr. subwatershed sites monitored in this study were: FC15 (Fishing Cr. at US 15), FC1607U (Fishing Cr. near SR 1607, Knotts Grove Rd., upstream of the outfall), OxfordEff (effluent from WWTP outfall), FC1607 (Fishing Cr. at SR 1607, below the outfall), FC1608 (Fishing Cr. at SR 1608, Fielding-Knotts Rd.), FC96 (Fishing Cr. at NC 96), UTFC1616 (UT to Fishing Cr. at SR1616, Tommie Sneed Rd.), and FC1643 (Fishing Cr. at SR 1643, Eaton Rd.). FC15 was monitored only for field measurements and habitat assessments. This site had extremely poor flow during the entire study period. Small impoundments, possibly small beaverdams, were common in this reach. The immediately surrounding land use upstream of the US 15 was wooded, though of poor quality: privet and other exotics were extremely common, if not dominant, in the understory. This catchment had a high amount of Developed land use, including industrial facilities. The habitat assessment score was 44, the lowest score of all sites in the study. All metrics directly assessing instream habitat were extremely low. The only metrics receiving high scores were for Channel Modification (some sinuosity is present though bends are infrequent), Light Penetration, and Riparian Zone Width. Aside from these positives, available habitat for colonization was extremely rare (


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Fecal coliform values at FC1607U were actually unexpectedly low and showed the lowest median value (73 col/100mL) of all sites in the LWP area. Bacteria levels, however, increased significantly during stormflow (3600 col/100mL). Nutrient levels were, overall, some of the lowest of all sites in the study, especially ammonia. Aluminum (median = 173 µg/L) and iron (median = 505 µg/L) were unusually low; the source of these metals is generally assumed to be soils, so this site may have lower soil inputs or soil types may just be different in this catchment. A few samples for copper and zinc had reportable levels, as would be expected in an urban watershed, though concentrations were relatively low. Residues and turbidity were both low, even during storm flow: the maximum value recorded for total suspended residues was 26 mg/L and for turbidity was 50 NTU. Perhaps the only chemical or physical indication of impacts from developed areas upstream (besides bacteria during stormflow) is an elevated specific conductance with a median of 160 µS/cm at 25°C, essentially equivalent to that seen in nearby Foundry Branch. OxfordEff: Below FC1607U, Foundry Br. joined Fishing Cr., and the outfall for the Oxford WWTP was located a few meters downstream. The most notable differences between the effluent and receiving water were pH and specific conductance. The effluent had a median pH of 7.6 SU and a maximum of 8.5 SU. Median pH upstream in Fishing Cr. was 7.0 SU, and in Foundry Br. was 6.9 SU. Specific conductance was incredibly elevated: the median of the effluent was 600 µS/cm at 25°C. FC1607: When looking at instream values downstream of the mixing zone at site FC1607, it is apparent that dilution is not having any real effect. Specific conductance ranged from 178-721 µS/cm at 25°C, which disallowed fish community sampling at this location since electrofishing becomes dangerous to field staff and lethal to aquatic fauna with conductance at these levels. The pH was more basic as compared to upstream with a median of 7.5 SU (range: 7.0-7.9 SU). Instream bacteria levels were significantly elevated as compared to values upstream in Fishing Cr. and Foundry Br., with a median of 370 col/100mL and a maximum of 10,000 col/100mL. Slight increases in total suspended residues (median = 8.5 mg/L) and turbidity (median = 18 mg/L) were noted, though these values are still relatively low. At FC1607 concentrations of metals are concerning, particularly zinc. The NC action level for zinc for protection of aquatic life is 50 µg/L; six of seven samples analyzed showed instream concentrat

fishing creek water quality study quality/surface...fishing cr. lwp area water quality study report...

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