NC0024228_wasteload allocation (Scoping Analysis)_20060301

Water Quality Modeling Scoping Analysis
for the High Point Westside Discharge to
Rich Fork Creek
Prepared by:
TETRATECH, INC.
3200 Chapel Hill -Nelson Hwy.
Research Triangle Park, NC 27709
March 2006

WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Table of Contents
List of Tables ii
List of Figures iii
1 Introduction 1
1.1 Background 1
1.2 Overview of Project Approach 3
1.2.1 Compilation and Review of Existing Information 3
1.2.2 Setup and Review of Existing DWQ Water Quality Model 4
1.2.3 Stream Reconnaissance 4
1.2.4 Additional Modeling Analyses and Evaluation of Assimilative Capacity 4
2 Review of Existing Water Quality Information 7
2.1 Flow Conditions for Evaluating Water Quality Data 7
2.2 Instream Water Quality Data 10
2.2.1 Summary of Data Collected 10
2.2.2 Summarize Relevant Information 17
2.3 Plant Effluent Quality Data 19
2.4 Digital Orthophotos and MRLC Land Use Data 21
2.5 Anecdotal Information 22
2.5.1 Westside WWTP Correspondence 22
2.5.2 DWQ Modeling Files 23
2.5.3 Black & Veatch Field Reconnaissance 23
2.5.4 Summary of Notes from Different Parties Regarding Conditions Affecting Quality 23
2.6 Tetra Tech Whole Effluent Toxicity Studies 23
3 Review of Existing Water Quality Model 29
3.1 Summary Of Modeling Information Compiled From DWQ 29
3.1.1 Black & Veatch Report 29
3.1.2 DWQ Modifications to Black & Veatch Modeling 30
3.2 Tetra Tech Model Evaluation Analyses 32
4 Stream Reconnaissance 37
5 Additional Modeling Analysis and Evaluation of Assimilative Capacity 43
6 Overall Conclusions and Recommendations 49
6.1 Potential For Increased Waste Flows From Westside WWTP 49
6.2 Recommended Next Steps 49
7 References 51
Appendix A. Photos and Field Notes from January 2006 Field Reconnaissance A-1
Appendix B. More Detailed Description of Field Studies Recommended for Next
Steps in Supporting Rich Fork Creek QUAL2E Modeling and Wasteload
Allocation B-1
TETRATECH, INC.

WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
List of Tables
Table 1. Summary of YPDRBA Data for Rich Fork Creek (1998 through 2005) 12
Table 2. Summary of Westside Instream Data for Rich Fork Creek (Summer 2005) 14
Table 3. NLCD 1992 Land Cover in Rich Fork Creek Watershed 22
Table 4. DEM Hydraulic Parameters for Rich Fork Creek 31
Table 5. Reaction Rates Used in the DEM QUAL2E Model for Rich Fork Creek 31
Table 6. Headwater and Westside WWTP Model Inputs for September 20, 2005 35
Table 7. Fixed Velocities, Widths, and Depths for the Pools and Unaltered Channels
of Rich Fork Creek 43
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
List of Figures
Figure 1. Location of the Westside WWTP and Rich Fork Creek 2
Figure 2. Location of the Abbotts Creek Gage (USGS 02121500) with Respect to
Rich Fork Creek 8
Figure 3. Daily Flows at Abbotts Creek Gage (USGS 02121500) from January 1998
through October 2005 9
Figure 4. Cumulative Summer Flows (May through October) at Abbotts Creek Gage
(USGS 02121500) 9
Figure 5. Water Quality Monitoring Stations in Rich Fork Creek 11
Figure 6. Box Plots of Dissolved Oxygen Data Collected at YPDRBA Monitoring Sites13
Figure 7. Box Plots of Dissolved Oxygen Data Collected at Westside Monitoring Sites 15
Figure 8. Observed Dissolved Oxygen Concentrations on Three Dates Representing
Various Flow and Temperature Conditions 16
Figure 9. DO Concentrations at Four Primary Stations in Rich Fork Creek, by Month 17
Figure 10. Frequency of Excursions of the DO Standard (5 mg/L) 18
Figure 11. Daily BOD5 Concentrations Discharged from the Westside WWTP 19
Figure 12. Monthly Average BOD5 Concentrations from the Westside WWTP 20
Figure 13. Monthly Average Discharge Flowrate from the Westside WWTP 20
Figure 14. 1992 NLCD Land Use Coverage for the Rich Fork Creek Watershed 21
Figure 15. Rich Fork Creek 250 Meters Upstream of the WWTP Plant, Facing
Downstream 24
Figure 16. Rich Fork Creek 150 Meters Upstream of WWTP Plant, Facing Downstream 25
Figure 17. Rich Fork Creek 5 Meters Upstream of WWTP, Facing Upstream 25
Figure 18. Rich Fork Creek 5 Meters Upstream of WWTP, Facing Downstream 26
Figure 19. Rich Fork Creek 10 Meters Downstream of WWTP, Facing Downstream 26
Figure 20. Rich Fork Creek 180 Meters Downstream of WWTP, Facing Upstream 27
Figure 21. Rich Fork Creek 270 Meters Downstream of WWTP, Facing Upstream 27
Figure 22. Comparison of Simulated and Observed Instream Velocity When Headwater
Flow is 0.25 cfs 32
Figure 23. Comparison of Simulated and Measured Depth When Headwater
Flow is 0.25 cfs 33
Figure 24. Comparison of Reaeration Rates Using DWQ Simulated Velocity and Depth
and Black & Veatch Observed Velocity and Depth 34
Figure 25. Comparison of DWQ QUAL2E Model to Observed Data 36
Figure 26. Sites Visited During January 2006 Field Reconnaissance 38
Figure 27. Example of Floodplain Along Unmined Section of Rich Fork Creek,
Near Midway Road 39
Figure 28. Example of Sediment Deposition in Rich Fork Creek 39
Figure 29. Comparison of Substrate Composition in Unaltered and Sand Dipped Portions
of the Channel, Respectively 40
Figure 30. Comparison of Organic Layer at Highway 109 Pool (- linch), Ball Road Pool
(-1/4 inch), and Kanoy Road Pool (-1/8 inch) , Respectively 40
Figure 31. Sand Dipping Crane at Active Mining Site Upstream of Highway 109 41
Figure 32. 1998 Orthophoto Showing Change in Channel Width Upstream and
Downstream of Ball Road Bridge 42
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 33. Comparison of Stream Channel Upstream and Downstream of Ball Road
Bridge, Respectively 42
Figure 34. Comparison of Tetra Tech Low Flow Simulation to Observed Dissolved
Oxygen on September 20, 2005 44
Figure 35. Impacts of Channel Restoration and WWTP BOD Load Reduction on
Simulated Dissolved Oxygen Concentrations in Rich Fork Creek 45
Figure 36. Impacts of SOD and BOD Load Reduction on Simulated Dissolved Oxygen
Concentrations in Rich Fork Creek 46
Figure 37. Comparison of Monthly BOD5 Load to Permitted Monthly Load 47
DTETRATECH, INC.

WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
1 Introduction
1.1 BACKGROUND
The City of High Point Westside Wastewater Treatment Plant (WWTP) discharges to Rich Fork Creek,
which flows into Abbotts Creek before entering High Rock Lake (Figure 1). Data collected by the city
and the North Carolina Division of Water Quality (DWQ) show that dissolved oxygen (DO) levels
downstream of the facility frequently drop below the state water quality standard of 5 mg/L during the
warm summer months. The city is interested in expanding its WWTP discharge with a higher quality of
effluent. However, DWQ has indicated that the existing wasteload allocation modeling shows there is a
lack of additional assimilative capacity downstream of the facility.
Tetra Tech was hired by the city and its engineering consultant, Hazen & Sawyer, to provide third party
expert services to evaluate existing data on assimilative capacity in Rich Fork Creek and examine whether
more detailed modeling would help shed light on available assimilative capacity and discharge impacts.
High-level modeling typically involves collection of significant amounts of field data to calibrate and
validate models, which can be time and resource intensive. Prior to investing extensive city resources in
such an endeavor, Tetra Tech recommended that a modeling scoping analysis and field reconnaissance be
performed to assess the potential benefits of more detailed modeling.
This report summarizes the findings of the scoping analysis and field reconnaissance and makes
recommendations for next steps.
NTETRATECH, INC.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
• Westside WWTP
A/Rich Fork Creek
Abbotts Creek
High Rock Lake
,/ " Lower Yadkin Hydrography
County Boundaries
20
0
20
N
40 Miles
Figure 1. Location of the Westside WWTP and Rich Fork Creek
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
1.2 OVERVIEW OF PROJECT APPROACH
Tetra Tech's general approach to the scoping analysis was to examine the current modeling methods and
assumptions used by DWQ for the Rich Fork discharge allocation in the context of actual monitoring data
and receiving stream features. Tetra Tech analyzed the application to determine which parameters and
processes seem to be most important in predicting the observed low DO concentrations, and whether there
are plausible rates for key variables (velocity, reaeration, sediment oxygen demand, carbonaceous
biochemical oxygen demand (CBOD) and nitrogenous biochemical oxygen demand (NBOD) decay, etc.)
under which potentially positive outcomes would result from more detailed modeling. Reconnaissance of
existing receiving stream features was conducted to help evaluate the appropriateness of existing model
assumptions and the likelihood for model rates to change substantially if further detailed monitoring and
modeling were performed.
1.2.1 Compilation and Review of Existing Information
The first step in the scoping analysis was to compile existing data and information from DWQ, the City of
High Point, and previous Tetra Tech studies. This review resulted in a better understanding of the
relationship between the plant and water quality in Rich Fork Creek. Comparison of the original model to
more recent monitoring data indicates that updates to the existing wasteload allocation model are needed
with regard to plant effluent quality, hydraulic parameterization, and reaeration assumptions to obtain an
accurate representation of impacts in Rich Fork Creek.
1.2.1.1 DWQ Files
DWQ supplied Tetra Tech with copies of the model input files, project notes, and permit documents used
for the wasteload allocation of Westside WWTP. A copy of the original Black & Veatch water quality
report was also obtained for purposes of acquiring time of travel studies and cross sectional data.
DWQ has collected monthly DO data on Rich Fork Creek at station Q5780000 (State Road 1800/Midway
School Road). This data was combined with DO data from other sources to assess DO trends in Rich
Fork Creek.
Sediment oxygen demand (SOD) data was also obtained from DWQ for stations in the Yadkin River
Basin (Dianne Reid, 2005). The SOD rates used in the original DWQ model are based on Black &
Veatch instream measurements, which are within the range of SOD rates reported by the state for this
basin.
1.2.1.2 High Point Data
The City of High Point provided electronic DMR data for the Westside WWTP from January 1997
through November 2005. This data included daily measurements of effluent flow and measurements of
pH, temperature, DO, ammonia, 5-day biochemical oxygen demand (BOD5), and total suspended solids
(TSS) approximately five days per week. Measurements of nitrate plus nitrite, total Kheldahl nitrogen
(TKN), total nitrogen (TN), and total phosphorus (TP) were collected approximately once per week.
These data were used to set the discharge flow and pollutant concentrations in the QUAL2E model.
Tetra Tech calculated average monthly BOD5 concentrations and discharge flowrates. From 1997 to
2005, the plant was compliant with the monthly average BOD5 limit 79 percent of months and the
flowrate limit 98 percent of months.
In the summer of 2005, staff at the Westside WWTP began collecting DO, temperature, and pH at eight
locations in Rich Fork Creek three to five times per week. Simulated DO was compared to data collected
at each of these stations to compare predicted concentrations throughout the length of Rich Fork Creek.
TETRATECH, INC.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
1.2.1.3 Yadkin Pee -Dee River Basin Association Data
The City of High Point Westside WWTP is a member of the Yadkin Pee -Dee River Basin Association
(YPDRBA), which is a coalition of effluent dischargers who work together to collect instream water
quality data in receiving streams. The association has compiled water quality data upstream of Westside
WWTP and at two downstream locations since June 1998. Weekly observations include temperature,
DO, pH, conductivity, and turbidity. Nutrient data are collected monthly. These data were used to set
headwater conditions and assess DO trends at two downstream locations.
1.2.1.4 Tetra Tech Whole Effluent Toxicity Study
The Owings Mills office of Tetra Tech was contracted by the Water Environment Research Foundation to
test whether or not whole effluent toxicity (WET) tests are good indicators of overall stream health. Six
dischargers were selected to participate in this study representing a range of influent and effluent
conditions including industrial, municipal, effluent dominated and with/without a history of chronic
toxicity. Dischargers make up 60 to 100 percent of the receiving streamflow under 7Q10 conditions.
The Westside WWTP volunteered as one of the six dischargers assessed in the study. WET testing was
performed with Ceriodaphnia dubia, Pimephales promelas, and Raphidocelis subcapitata.
Bioassessments were taken for benthic macroinvertebrates, periphyton, and fish. Habitat assessments
were taken at five sites along Rich Fork Creek.
Preliminary data on biological impacts have been collected, but results have not yet been published. The
RTP office of Tetra Tech has acquired the field data sheets and digital photos of Rich Fork Creek, which
will serve as aids to qualitatively check model assumptions and assess restoration potential.
1.2.1.5 Streamflow Information
US Geological Survey (USGS) does not maintain a streamflow gage on Rich Fork Creek. Flows were
extrapolated from USGS gage 02121500 for Abbotts Creek (at Lexington), which Rich Fork Creek drains
into further downstream of the gage. The drainage area at this gage is 174 square miles. The drainage
area at YPDRBA station Q5750000 is 9.83 square miles (NCDWQ, 2004). Thus, a drainage area ratio of
0.056 was used to estimate flows on Rich Fork Creek upstream of the wastewater treatment.
1.2.2 Setup and Review of Existing DWQ Water Quality Model
Tetra Tech set up a QUAL2E model for Rich Fork Creek and Westside WWTP using the DWQ version
of the model. The DWQ model was outdated with respect to plant upgrades, which occurred after the
original wasteload allocation.
1.2.3 Stream Reconnaissance
Reconnaissance was performed by Tetra Tech at 11 sites along Rich Fork Creek and in the three major
tributaries. The purpose of the trip was to gather information on channel structure, substrate composition,
and source loads that may not have been accounted for in previous modeling. In particular, Tetra Tech
focused on identifying potential reasons for the sharp drop in DO below the outfall that are not accounted
for by current modeling assumptions.
1.2.4 Additional Modeling Analyses and Evaluation of Assimilative
Capacity
Tetra Tech reconfigured the existing QUAL2E model to better represent the stream system based on more
recent water quality data and stream reconnaissance. Headwater quality and plant effluent quality
measured on September 20, 2005 were used as model input, and DO data collected by the Westside
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
facility on the same day were used to confirm model accuracy. The updated model was then used to
determine what changes would be required to bring the DO above the standard during low flow
conditions.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
2 Review of Existing Water Quality Information
2.1 FLOW CONDITIONS FOR EVALUATING WATER QUALITY DATA
Water quality on Rich Fork Creek is strongly correlated to streamflow. There is no USGS streamflow
gage on Rich Fork Creek, so flows in nearby Abbotts Creek (Figure 2) were plotted to show the
correlation between streamflow and excursions of the DO standard. Daily flows are shown in Figure 3,
and cumulative summer flows are shown in Figure 4. Note that 2003 was a relatively high flow year, and
that 2000 through 2002 and 2005 were estimated to be relatively low flow years. This will be referred to
when discussing water quality observations.
NTETRATECH, INC.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
• Westside WWTP
• USGS Gage 02121500
A/ Rich Fork Creek
// Abbotts Creek
A/ Lower Yadkin Hydrography
7
0
7
N
14 Mi
Figure 2. Location of the Abbotts Creek Gage (USGS 02121500) with Respect to
Rich Fork Creek
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul- Jan- Jul-
98 98 99 99 00 00 01 01 02 02 03 03 04 04 05 05
Figure 3. Daily Flows at Abbotts Creek Gage (USGS 02121500) from January 1998 through
October 2005
Cumulative Summer Flow (MG)
60,000 -
50,000
40,000
30,000
20,000
10,000
JTI..I
Ft
1998 1999 2000 2001 2002 2003 2004 2005
Figure 4. Cumulative Summer Flows (May through October) at Abbotts Creek Gage
(USGS 02121500)
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
2.2 INSTREAM WATER QUALITY DATA
The City of High Point Westside WWTP is a member of YPDRBA, which is a coalition of dischargers
who collect water quality data in receiving streams located in the river basin. Data for Rich Fork Creek
are available from June 1998 to present.
In addition, the Westside WWTP has monitored DO, temperature, and pH at two upstream locations and
six downstream locations since July 2005. DWQ began collecting monthly DO samples in January 2000
at one location downstream of the plant. Tetra Tech has received this data through December 2004.
Figure 5 shows the location of these monitoring stations along Rich Fork Creek. Site descriptions are
listed in Table 1 and Table 2 along with data summaries by station.
2.2.1 Summary of Data Collected
The largest database of water quality data for Rich Fork Creek is maintained by YPDRBA. Station
Q5750000 is located upstream of the WWTP at State Road 1755. Two downstream stations are also
monitored: Q5785000 at State Road 1787/Kanoy Road and Q5790000 at State Road 2123/Old Highway
29. Temperature, DO, pH, conductivity, and turbidity are analyzed weekly Ammonia, nitrite plus
nitrate, TKN, and TP are analyzed monthly. Table 1 and Figure 6 summarize the water quality data
collected at these three sites.
The Westside WWTP began collecting DO, temperature, and pH data at eight sites on Rich Fork Creek in
July 2005, five days per week. Table 2 and Figure 7 summarize this data.
DWQ provided Tetra Tech with monthly DO data collected from January 2000 through December 2004
at Q5780000 (State Road 1800/Midway Road). The minimum observed DO concentration at this location
is 4.0 mg/L, the average is 7.9 mg/L, and the maximum is 13.5 mg/L.
E. TETRATECH, INC.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
n HUC Boundary
DWQ Station
• YPDRBA Stations
* Westside Monitoring Stations
A/ Rich Fork Creek
tv/ HUC Hydrography
6
0
N
6 Miles
Figure 5. Water Quality Monitoring Stations in Rich Fork Creek
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
Table 1. Summary of YPDRBA Data for Rich Fork Creek (1998 through 2005)
Station
Parameter
Minimum
Average
Maximum
Q5750000 - 1.3
miles upstream of
the WWTP at State
Road 1755 /
Lexington Avenue
Temperature (°C)
1.0
17.9
25.9
DO (mg/L)
3.3
7.2
12.9
pH
6.6
7.4
8.3
Conductivity (µmhos/cm)
72
186
368
Turbidity (NTU)
3.4
21.1
241.0
Ammonia (mg-N/L)
0.01
0.1
0.9
Nitrate plus Nitrite (mg-N/L)
0.01
0.1
0.4
TKN (mg-N/L)
0.1
0.5
2.4
TP (mg-P/L)
0.01
0.1
0.6
Q5785000 - 3.9
miles downstream
of the WWTP at
State Road 1787 /
Kanoy Road
Temperature (°C)
1.5
18.8
27.9
DO (mg/L)
2.9
6.1
11.4
pH
6.5
7.3
8.4
Conductivity (µmhos/cm)
93
295
719
Turbidity (NTU)
2.0
22.0
400
Ammonia (mg-N/L)
0.01
0.2
1.6
Nitrate plus Nitrite (mg-N/L)
0.1
3.4
11.2
TKN (mg-N/L)
0.1
1.3
3.9
TP (mg-P/L)
0.01
0.5
2.3
Q5790000 - 9 miles
downstream of the
WWTP at State
Road 2123 / Old
Highway 29
Temperature (°C)
1.0
18.5
26.1
DO (mg/L)
3.0
6.8
12.2
pH
6.7
7.4
8.3
Conductivity (µmhos/cm)
88
253
470
Turbidity (NTU)
1.9
22.4
300
Ammonia (mg-N/L)
0.01
0.1
0.6
Nitrate plus Nitrite (mg-N/L)
0.1
1.8
8.0
TKN (mg-N/L)
0.1
0.9
1.9
TP (mg-P/L)
0.01
0.3
1.5
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
14
13
12
11
10
9
8
a)
7
O 6
5
4
3
2
1
0
Li Median n 25%-75% n Non -Outlier Range Outliers
Q5750000
Q5785000
Station
Q5790000
Standard
Figure 6. Box Plots of Dissolved Oxygen Data Collected at YPDRBA Monitoring Sites
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
Table 2. Summary of Westside Instream Data for Rich Fork Creek (Summer 2005)
Station
Parameter
Minimum
Average
Maximum
Q5750000 - 1.3
miles upstream of
the WWTP at State
Road 1755 /
Lexington Avenue
Temperature (°C)
6.2
19.1
27.3
DO (mg/L)
5.5
7.5
11.1
pH
6.7
7.5
8.2
CHP1 - 20 feet
upstream of the
WWTP discharge
Temperature (°C)
5.2
18.9
26.8
DO (mg/L)
4.0
7.1
10.9
pH
6.4
7.4
7.9
CHP3 - 0.3 miles
downstream of the
WWTP at Highway
109
Temperature (°C)
7.0
20.6
27.6
DO (mg/L)
4.5
7.1
10.9
pH
6.3
7.2
7.9
Q5780000 - 1.4
miles downstream
of the WWTP at
State Road 1800 /
Midway School Rd
Temperature (°C)
7.4
20.7
29.1
DO (mg/L)
3.0
5.8
10.3
pH
6.5
7.2
7.8
CHP4 - 2.9 miles
downstream of the
WWTP at State
Road 1790 / Ball Rd
Temperature (°C)
6.8
20.1
29.0
DO (mg/L)
2.8
5.7
10.4
pH
6.4
7.2
7.8
Q5785000 - 3.9
miles downstream
of the WWTP at
State Road 1787 /
Kanoy Road
Temperature (°C)
7.0
20.2
28.8
DO (mg/L)
2.6
5.7
10.5
pH
6.3
7.2
7.9
CHP5 - 6.6 miles
downstream of the
WWTP at Evans Rd
Temperature (°C)
6.8
19.6
29.4
DO (mg/L)
3.4
6.1
10.7
pH
6.0
7.3
7.9
Q5790000 - 9 miles
downstream of the
WWTP at State
Road 2123 / Old
Highway 29
Temperature (°C)
6.8
19.6
31.2
DO (mg/L)
2.8
6.0
10.6
pH
6.5
7.3
8.2
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
14
13
12
11
10
9
8
0)
E 7
0 6
G
5
4
3
2
1
0
= Median T 25%-75% T Non -Outlier Range Outliers
Q5750000 CHP1
Standard
CHP3 Q5780000 CHP4 Q5785000 CHP5 Q5790000
Station
Figure 7. Box Plots of Dissolved Oxygen Data Collected at Westside Monitoring Sites
Both the YPDRBA and Westside data show a drop of approximately 1.5 mg/L in DO downstream of the
plant discharge. Tetra Tech plotted daily DO collected by the plant to see if that trend occurred on a daily
basis, or if it was just a product of the means.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
On almost every day that Westside collected DO data, a drop of 1 to 2 mg/L of DO is observed within
three miles of the plant discharge. On high flow and/or low temperature days, the standard of 5 mg/L is
still met. Figure 8 shows the DO on three sampling days with varying flow and temperature conditions.
August 10th, 2005 had an estimated flow rate of 24 cfs and an average water temperature of 23.7 °C (high
flow, high temperature). DO decreases by 1.3 mg/L, but does not drop below the standard. The flow rate
on September 20th, 2005 was approximately 0.5 cfs, and the average water temperature was 22.7 °C (low
flow, high temperature). The DO drops by 1.6 mg/L and does not meet the standard. October 19th, 2005
had a flow rate of approximately 1 cfs and a water temperature of 16.8 °C (low flow, low temperature).
The DO dropped by 1.9 mg/L, but the standard was still met. These data confirm that the critical
conditions for this creek are low flow coupled with high temperature.
8
10/19/05 (low flow, low temp)
8/10/05 (high flow, high temp)
9/20/05 (low flow, high temp)
Standard
•
7
a 5.
4
•
E
0 3
2
1-
0
0.0
2.0
4.0 6.0 8.0
Distance from WWTP (miles)
10.0
Figure 8. Observed Dissolved Oxygen Concentrations on Three Dates Representing Various
Flow and Temperature Conditions
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
2.2.2 Summary of Relevant Information
Tetra Tech combined the DO data from YPDRBA, Westside WWTP, and DWQ into one database to
assess DO trends in Rich Fork Creek. The Westside data were also used to compare simulated DO
concentrations to observations at multiple locations in the creek.
The majority of the DO data has been collected at four locations: Q5750000, Q5780000, Q5785000, and
Q5790000. Data from these stations (June 1998 through December 2005) were plotted by month to
identify seasonal trends (Figure 9). Excursions of the DO standard (5 mg/L) only occurred during the
summer months (May through October).
• Q5750000 • Q5780000 A Q5785000 • Q5790000
Figure 9. DO Concentrations at Four Primary Stations in Rich Fork Creek, by Month
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
The frequency of excursions at each of the four primary stations was estimated for each year from 1998
through 2005 (Figure 10). Data were not collected at Q5780000 prior to the year 2000, so the number of
excursions at this station in 1998 and 1999 could not be estimated. No excursions were observed in 2003
at any station. Excursions were typically highest at station Q5785000 (— 3.9 miles downstream of
Westside WWTP) and lowest at Q5750000 (upstream of Westside WWTP).
Frequency of Excursions
60%
50%
40%
30%
20%
10%
0%
1
■ Q5750000 0 Q5780000 0 Q5785000 0 Q5790000
1998 1999 2000 2001 2002 2003 2004 2005
Figure 10. Frequency of Excursions of the DO Standard (5 mg/L)
In 2003, the flow at Abbotts Creek did not drop below 58 cfs, and no excursions were observed that year.
In 2004 the minimum flow was 16 cfs, and excursions occurred less than 10 percent of the time at the two
downstream monitoring locations where excursions were observed. The year 2001 had greater than 10
percent excursions at each of the four monitoring stations; this year also had the lowest cumulative flow
volume from 1998 to 2005. Year 2005 had the highest frequency of excursions at the downstream
stations. A leaky sewer main at Chesnut Street discharged an unknown amount of raw sewage into the
stream during the summer of 2005 (Skee, 2006).
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
2.3 PLANT EFFLUENT QUALITY DATA
To further understand potential influences on the instream DO concentrations and patterns, Tetra Tech
analyzed the High Point effluent and nonpoint source loads. Scoping analysis of the point source is
provided below, and scoping of nonpoint sources is summarized in Section 2.4.
The City of High Point Westside WWTP provided Tetra Tech with effluent quality data from January
1997 to November 2005. Figure 11 shows the daily BOD5 concentrations discharged from the plant.
There is no daily maximum BOD5 concentration limit for the Westside facility.
BOD5 at 20C (mg/L)
80
70
60
50
40
30
20
10
Average Daily Effluent Concentration
f
0 1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
°°1 °°1 °°w °oo °oo o°° o°Z, o°,. o°ti o°� o°� o°t` � h
�•� o�� °�� ,J� o�� ��ti o�ti ,�1\ti ti°�� �.�ti x°�� ,��( �yo>``'
'�� o,� �� ��ti °�ti rod `L °� �� "� NI\ A\
Figure 11. Daily BOD5 Concentrations Discharged from the Westside WWTP
Tetra Tech calculated the average monthly BOD5 concentrations for comparison to the monthly average
permit limit of 5 mg/L from April 1 to October 31 and 10 mg/L from November 1 to March 31. Figure
12 shows the average monthly reported values compared to the permitted concentrations. The Westside
plant was compliant with the BOD5 limit 79 percent of the months reported.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
—Average Monthly Discharge Concentration Average Monthly Limit
16
14-
12-
4
2-
,N
0
Jan-97 Feb-98 Mar-99 Apr-00 May-01 Jun-02 Jul-03 Sep-04 Oct-05
Figure 12. Monthly Average BOD5 Concentrations from the Westside WWTP
The permitted monthly average flowrate is 6.2 MGD. Figure 13 compares the monthly average of daily
reported flows to the permit limit. Since 1997, the plant was compliant with the flowrate limit 98 percent
of the months reported.
—Average Monthly Discharge Flowrate —Average Monthly Limit
1
0
Jan-97 Feb-98 Mar-99 Apr-00 May-01 Jun-02 Jul-03 Sep-04 Oct-05
Figure 13. Monthly Average Discharge Flowrate from the Westside WWTP
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
2.4 DIGITAL ORTHOPHOTOS AND MRLC LAND USE DATA
In order to assess upland sources of pollutant loading to Rich Fork Creek, Tetra Tech downloaded 1998
digital orthophotos from DOT and the 1992 National Land Cover Data (NLCD) land use cover from the
Basins website. The orthophotos show several mobile home parks within one-half mile of the creek. The
majority of the riparian buffer is either forested or agricultural fields. Much of the eastern third of the
watershed is in urban development.
Figure 14 shows the NLCD land use coverage (30-m resolution). The watershed boundary is the 14-digit
hydrologic unit acquired from Basinpro. Note that the areas draining to Jimmys Creek and Hamby Creek
do not drain to the simulated segments of Rich Fork Creek. Comparison of the orthophotos to the land
use coverage show that the NLCD generally depicts the extent of urban development accurately through
at least 1998. Table 3 summarizes the land cover data for the Rich Fork Creek watershed.
* Westside WWTP
Streams
NL D
Barren or Mining
Transitional
Agriculture - Cropland
Agriculture - Pasture
= Forest
Upland Shrub Land
Grass Land
= Water
Wetlands
Low Intensity Residential
Other Grasses (parks, lawns, etc.)
High Intensity Residential
High Intensity Commercial/Industrial
3
0
3
6 Miles
N
Figure 14. 1992 NLCD Land Use Coverage for the Rich Fork Creek Watershed
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
Table 3. NLCD 1992 Land Cover in Rich Fork Creek Watershed
Land Use
Area (ac)
Percent
Open Water
88.5
0.2%
Low Intensity Residential (1/3 ac)
6,061.1
14.3%
High Intensity Residential (1/8 ac,
townhouses, etc)
1,847.7
4.3%
Commercial/Industrial/Transportation
3,624.6
8.5%
Bare Rock/Sand/Clay
56.9
0.1%
Quarries/Strip Mines/Gravel Pits
172.8
0.4%
Transitional
-
0.0%
Deciduous Forest - Fair
16,340.9
38.5%
Evergreen Forest - Fair
2,387.9
5.6%
Mixed Forest - Fair
2,779.0
6.5%
Pasture/Hay - Fair
4,485.0
10.6%
Row Crops, straight, good
3,814.3
9.0%
Other Grasses/Urban/Recreation,
>50% grass
303.1
0.7%
Woody Wetlands - Poor Forest
492.4
1.2%
Emergent Herbaceous Wetlands -
Inundated Forest
21.3
0.1%
Total
42,475.6
100.0%
2.5 ANECDOTAL INFORMATION
Tetra Tech gathered anecdotal information concerning Rich Fork Creek from the Westside WWTP,
DWQ, and the Tetra Tech Owings Mills office to include all information available to date concerning the
overall health of Rich Fork Creek.
2.5.1 Westside WWTP Correspondence
According to staff at the Westside WWTP, instream DO concentrations are not well correlated to plant
effluent quality and have not responded significantly to plant upgrades. The plant manager (Bill Frazier)
states that historic agriculture has burdened the stream with sediment and damaged instream habitat.
During the recent fecal coliform TMDL for Rich Fork Creek, the plant utilized DNA tracing to identify
the sources of the fecal coliform load. The plant states that the majority of the fecal coliform loading is
not from human sources, and that what is human is not originating from the treatment plant or its
collection system, but rather from septic systems and package treatment plants.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
2.5.2 DWQ Modeling Files
Tetra Tech examined the modeling report, modeling notes, and permitting files of DWQ for additional
information concerning low DO in Rich Fork Creek. In August 1986, DWQ cited poor quality effluent as
the source of DO excursions and noted that large accumulations of sludge and sediment occurred
downstream of the plant. Several correspondence letters question the estimation of the 7Q10 for Rich
Fork Creek above the plant. DWQ noted several days were there was zero flow upstream of the
discharge. The allocation report stated that two fish kills occurred downstream of the plant in 1983 due to
toxic substances.
2.5.3 Black & Veatch Field Reconnaissance
The Black & Veatch report lists findings from a field reconnaissance which took place during the summer
of 1986 between the WWTP discharge and Evans Road (approximately 6.5 miles downstream of the
plant). The report notes sludge deposits visible from the Highway 109 Bridge to the confluence with
Hamby Creek. Deposits were typically covered by 1/4 to %2 inch of clean sand during the summer visit.
During October and November field visits, sludge was covered by approximately 2 inches of clean sand.
It was their assessment that the sludge deposits were slowly disappearing following the plant upgrades of
September 1986. It is more likely that higher flows in the fall carried a greater sediment load, which was
later deposited on the sludge.
Black & Veatch attributed the large number of trees in the stream to undercut banks no longer able to
support the trees.
2.5.4 Summary of Notes from Different Parties Regarding Conditions
Affecting Quality
The anecdotal information gathered on Rich Fork Creek confirms that DO concentrations are low during
the warm summer months during low flow conditions and that the stream is already exceeding its
assimilative capacity. Sludge accumulations were noted downstream of the plant, though it is unknown
whether the resulting SOD has diminished over the last 20 years following the plant upgrade in 1986.
2.6 TETRA TECH WHOLE EFFLUENT TOXICITY STUDIES
The Owings Mills office of Tetra Tech conducted habitat assessments and bioassessments of
Ceriodaphnia dubia, Pimephales promelas, and Raphidocelis subcapitata in the 250 meters up and
downstream of the Westside WWTP. Results of the study have not been finalized, but Tetra Tech RTP
was able to obtain the field data sheets and several digital photos of the stream.
The field data sheets indicate that the stream habitat is poor upstream and downstream of the plant.
Generalities are listed below that reflect conditions along the 500-meter reach studied:
1) Bed material is comprised primarily of sand.
2) Low percentage of stable substrate (less than 30 percent).
3) No submerged vegetation in ponds; bottom completely covered by mud, clay, or sand.
4) Shallow pools more prevalent than deep pools.
5) Low channel sinuosity.
6) Heavy deposits of fine material with increased bar development.
7) Moderate to high levels of bank erosion.
8) Larger particles surrounded by more than 75 percent fine sediment.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
9) Not all velocity / depth regimes present.
10) Low frequency of riffles; poor riffle habitat.
The field data sheets indicate little change in habitat functionality above and below the WWTP discharge.
The digital photos up and downstream of the plant are similar as well (Figure 15 through Figure 21).
Figure 15. Rich Fork Creek 250 Meters Upstream of the WWTP Plant, Facing Downstream
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 16. Rich Fork Creek 150 Meters Upstream of WWTP Plant, Facing Downstream
Figure 17. Rich Fork Creek 5 Meters Upstream of WWTP, Facing Upstream
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 18. Rich Fork Creek 5 Meters Upstream of WWTP, Facing Downstream
Figure 19. Rich Fork Creek 10 Meters Downstream of WWTP, Facing Downstream
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 20. Rich Fork Creek 180 Meters Downstream of WWTP, Facing Upstream
Figure 21. Rich Fork Creek 270 Meters Downstream of WWTP, Facing Upstream
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
3 Review of Existing Water Quality Model
3.1 SUMMARY OF MODELING INFORMATION COMPILED FROM NCDWQ
Tetra Tech visited the office of DWQ to obtain modeling reports, modeling notes, and electronic
modeling files. Some of the information went back 20 years and was very helpful in understanding the
water quality issues in Rich Fork Creek. The various sources of information are described below.
3.1.1 Black & Veatch Report
Black & Veatch (1987) completed a water quality study and QUAL2E model of Rich Fork Creek and the
Westside WWTP for the City of High Point, Davidson County, and the North Carolina Department of
Natural Resources. The study cited problems with odor downstream of the plant as well as fish kills and
noticeable sludge deposits. Black & Veatch modeled Rich Fork Creek with 13 reaches based on results of
several studies described briefly below.
Black & Veatch collected water quality samples at 10 locations along Rich Fork Creek on July 9 and
August 27, 1986 to obtain two independent data sets for purposes of model calibration and validation.
A flow determination study was performed on July 10, 1986 at several of the water quality monitoring
stations by measuring velocities with a Pigmy meter at 2-foot intervals across the stream and multiplying
by the corresponding cross sectional area. On July 10th, the headwater flows were estimated to be
0.25 cfs and a loss of 2.5 cfs was measured over 8.5 miles. Model runs have tributary flows set to zero
and incremental losses defined over the length of the creek.
A time of travel study was conducted from July 14 through July 20, 1986. Rhodamine dye was injected
at the point of discharge of the WWTP, and concentrations were measured at six stations with a
fluorometer. The time of passage of the maximum concentration from station to station was recorded to
estimate the time of travel. Travel velocities ranged from 0.08 to 0.24 feet per second with an overall
travel velocity of 0.1 feet per second.
A diurnal study was performed on September 18, 1986. DO, pH, temperature, and specific conductivity
were measured four times during the day at each of the 10 water quality stations. Data did not indicate
that algae contributed significantly to the DO balance, though field notes indicate that September 18 was
an overcast day.
Twelve cross sections were taken along Rich Fork Creek. Though water depths were recorded, the dates
were not, so there is no way to verify whether or not the cross sections were taken during the same period
as the flow determination and time of travel studies.
Tetra Tech evaluated USGS streamflows at Northern Potts Creek at Linwood (a tributary to High Rock
Lake; USGS gage 02121180) to compare flows during the hydraulic and water quality studies. The
Abbotts Creek gage went online in 1988, so flows were not available from this gage. Flows on Northern
Potts Creek were similar during the flow determination (1 cfs) and time of travel study (average 0.97 cfs).
During the water quality study (August 27, 1986), flows in Northern Potts Creek were approximately
2 cfs. Thus, flow conditions in a nearby creek were approximately twice as high during the water quality
study compared to the flow studies. For the model calibration run (August 27, 1986), Black & Veatch
had to increase headwater flows measured on July 10 from 0.25 cfs to 1.6 cfs and Kennedy Mill Creek
flows from zero to 0.5 cfs. A six -fold increase in headwater flow was required to simulate observed water
quality. Though the headwater flows were likely higher in August compared to July, Black & Veatch
probably overestimated headwater flow for this calibration run.
To calibrate the hydraulic parameters that define velocity, depth, and width based on flow, Black &
Veatch used the assumed headwater flow of 1.6 cfs with the time of travel data collected when flows were
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
closer to 0.25 cfs. Simulated flow and travel time matched observations well during the calibration run,
even though the headwater flows were six times higher than observed during the flow determination and
time of travel study. Travel times for the validation run were not shown, though water quality graphs for
the validation graph were shown. Because flows in nearby Northern Potts Creek were fairly stable in
July, the predicted travel times in the validation run should have been consistent with those determined
from July 14th through July 20th. Given the discrepancy in headwater flows and the apparent absence of
the validation data, it is not likely that the hydraulic parameters were calibrated well.
Plant effluent characteristics were based on data collected in the late 1980s. The ratio of ultimate CBOD
to BOD5 was assumed to be 2 and the ammonia concentration was 7.3 mg/L.
The reaeration option chosen for the simulation was Thackston and Krenkel (QUAL2E option 5). The
Tsivoglou and Wallace method was also considered. During the calibration run (August 27th), DO
concentrations are simulated to within 0.7 mg/L at the seven monitoring stations. During the validation
run (July 9th), predicted DO concentrations are within 4.5 mg/L of observed. Poor agreement during
validation indicates that the model does not accurately represent the system during low flow.
SOD measurements were taken upstream of the WWTP and at Midway Road. During calibration of DO,
Black & Veatch varied the SOD rates from 0.10 to 0.25 g/ft2/d in accordance with measured values and
inability of the lower reaches to recover DO at rates expected from reaeration.
The Black & Veatch modeling indicated that the monthly average allocation limits for BOD5 should be
reduced from 12 mg/L to 5 mg/L, and ammonia limits should be reduced from 5 mg/L to 2 mg/L. These
are the current permit limits as of January 2006.
3.1.2 NCDWQ Modifications to Black & Veatch Modeling
In late 1988, NC Department of Environmental Management (NCDEM, now DWQ) examined the
validity of the Black & Veatch QUAL2E model for Rich Fork Creek and identified several problems with
the model (DEM, 1989).
1) The version of QUAL2E used by Black & Veatch was outdated and did not include simulation of
organic nitrogen.
2) The flow measurements, time of travel study, cross section measurements, and water quality
studies were all performed on different dates.
3) The long-term BOD test was run for 30 days. Oxygen consumption was still occurring rapidly at
the end of the test, so ultimate BOD was not determined.
4) The ratio of CBOD to BOD5 was underestimated based on long-term BOD data collected by
DEM in August 1988.
5) The BOD decay rate of 0.5/day seemed high. The DEM bottle rate determined during the August
1988 study was 0.02/day. DEM estimated a decay rate of 0.05/day instream using the Bosco
equation. However, the most recent electronic files from DWQ show a BOD decay rate of
0.1/day in both the calibration and waste load allocation models.
6) The ammonia oxidation rate (0.4/day) was high compared to literature values (0.05 to 0.3/day).
7) The SOD rates ranged from 0.3 to 3.7 g/m2/d, which were somewhat high compared to other
values measured in North Carolina at that time (1 to 2 g/m2/d).
DEM modified the QUAL2E model by reducing the number of reaches from 13 to 8 and averaging the
hydraulic parameters from the Black & Veatch model to estimate velocity, depth, and width based on
flow. Reaches 1 through 4 were grouped together and reaches 5 through 8 were grouped together based
on change in average slope. DWQ modeling notes indicate that the average slope in the upper four
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
reaches is 7.5 feet per mile, and in the lower four reaches the average slope is 3.3 feet per mile. Table 4
summarizes the DEM hydraulic parameters.
Table 4. DEM Hydraulic Parameters for Rich Fork Creek
Reach
Velocity
Coefficient on
Flow
Velocity Depth
Exponent on Coefficient on
Flow Flow
Depth
Exponent on
Flow
Width
Coefficient on
Flow
Width
Exponent on
Flow
1-4
0.10
0.5
0.5
0.8
20
0.1
5-8
0.04
0.5
0.4
0.4
31
0.1
Reaction rates and reaeration options were also set for each group (Table 5).
Table 5. Reaction Rates Used in the DEM QUAL2E Model for Rich Fork Creek
Reaction Rate (1/day)
Reaches 1 - 4
Reaches 5 - 8
Organic Nitrogen Hydrolysis
0.1
0.05
Organic Nitrogen Settling
0.1
0.1
Ammonia Oxidation
0.2
0.2
Benthic Source of Ammonia
0.0
0.0
Nitrite Oxidation
0.5
0.5
BOD Decay
0.1
0.1
BOD Settling
0.0
0.0
Reaeration Option
Churchill
Owens and Gibbs
Simulated SOD rates vary beyond the two reach groups. In reaches 1 through 6, the SOD rate is 0.1
g/ft2/d, in reach 7 the SOD rate is 0.2 g/ft2/d, and in reach 8, the SOD rate is 0.25 g/ft2/d. These values
were not changed from the original Black & Veatch model. Black & Veatch indicated that higher SOD
rates were expected in the lower reaches due to an increase in sludge deposits corresponding to pooled
areas with low velocities.
DEM used the Monte Carlo simulation option to perform a sensitivity analysis for the prediction of DO.
DEM found that the velocity and depth equations, SOD rates, and the initial temperatures were the most
influential factors determining DO concentrations at the sag point. They recommended additional
monitoring studies to determine appropriate parameters for this system.
For the allocation run, the 7Q10 flows for Rich Fork Creek (0.67 cfs), Kennedy Mill Creek (0.1 cfs), and
Hunts Fork Creek (0.19 cfs) (DEM, 1989) were used along with treatment plant permit limits (6.2 MGD,
5 mg/L BOD5, and 2 mg/L ammonia). Incremental flows were assumed to be 0.073 cfs per mile. A
calibration run was set up, though the date is not specified in the file or the DEM report. For this run, the
headwater flow is 0.25 cfs, and there is no additional flow from Kennedy Mill Creek, Hunts Fork Creek,
or incremental sources.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
3.2 TETRA TECH MODEL EVALUATION ANALYSES
First, Tetra Tech ran the current DWQ model with a headwater flow of 0.25 cfs to determine if velocity,
depth, and width were consistent with the time of travel and cross section data collected by Black &
Veatch. In general, velocity was overpredicted (Figure 22), and depth was underpredicted (Figure 23).
Note that depths were recorded during cross section measurements and exact dates and flow conditions
are unknown.
■ Simulated Velocity with DWQ Model ❑ Time of Travel Study Measured Velocity
Velocity (feet per second)
0.30
0.25
0.20
0.15
0.10
0.05
0.00
1 2 3 4 5 6 7 8
QUAL2E Reach
Figure 22. Comparison of Simulated and Observed Instream Velocity When Headwater Flow
is 0.25 cfs
Th
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
3.50
3.00 -
2.50 -
2.00
t
GGi 1.50
ci
1.00
0.50
0.00
• Simulated Depth with the DWQ Model 0 Average Measured Depth
1
2 3 4 5
QUAL2E Reach
6
7
8
Figure 23. Comparison of Simulated and Measured Depth When Headwater
Flow is 0.25 cfs
Because the two reaeration options chosen by DWQ rely on velocity and depth for their calculation, Tetra
Tech compared the predicted reaeration rates (at 20 °C) using the DWQ simulated velocity and depth and
the average measured velocity and depth observed by Black & Veatch. DWQ assigned the Churchill
method for reaches 1 through 4 and the Owens and Gibbs method for reaches 5 through 8. The EPA
Rates, Constants, and Kinetics guide (USEPA, 1985) states that the Churchill method is applicable at
depths greater than two feet and velocities greater than 1.5 ft/s (Figure 24). Thus, during low flow
conditions, this method is not suitable for Rich Fork Creek. The Owens and Gibbs method is
recommended for depths less than two feet across all reasonable velocities. Tetra Tech calculated the
reaeration rates using observed widths and velocities with the Owens and Gibbs method. With the
exception of reach 1 and 3, the DWQ estimates of reaeration appear high.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
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Reaeration Rate at 20C (1/d)
4.5
4.0
• DWQ Simulated Reaeration o Reaeration Calculated with Observed Data
3.5 -
3.0 -
2.5
2.0 -
1.5
1.0
0.5 -
0.0
1 2 3 4 5 6 7 8
QUAL2E Reach
Figure 24. Comparison of Reaeration Rates Using DWQ Simulated Velocity and Depth and
Black & Veatch Observed Velocity and Depth
Tetra Tech ran the original DWQ model with data collected on 9/20/2005 to verify that the simulated
reaeration was too high and that simulated DO would be higher than observed. Plant effluent and
headwater quality were modified to reflect actual conditions for that day. No rates were changed for this
run.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
September 20, 2005 was chosen as the model run day to test the DWQ version of the QUAL2E model
based on availability of data and near steady-state conditions observed in a nearby creek (Abbotts Creek).
The headwater flow was assumed 0.55 cfs based on the ratio of drainage area at Rich Fork Creek above
the WWTP to Abbotts Creek at the USGS gage (0.056). DO concentrations were available at eight
locations in Rich Fork Creek from the Westside WWTP files, and nutrient data to characterize plant
effluent quality were available the day prior. Headwater BOD data were not available, so the DWQ
model calibration input value of 0.75 mg/L BODult was left unchanged. Table 6 summarizes the
headwater and WWTP inputs.
Table 6. Headwater and Westside WWTP Model Inputs for September 20, 2005
'Model Input
Headwater
Westside WWTP1
Flow (cfs)
0.55
5.1
Temperature (°F)
71.4
77
DO (mg/L)
6.4
6.8
Ammonia (mg-N/L)
0.01
0.04
TKN (mg-N/L)
0.29
1.42
NO3 plus NO2 (mg-N/L)
0.02
14.7
Organic N (mg-N/L)
0.28
1.38
BOD5 (mg/L)
No instream measurement. Use
BODult = 0.75 mg/L as in original
DWQ model.
<2
BODult (mg/L)
10
Nutrient data for Westside WWTP are from September 19, 2005.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 25 compares the DWQ simulation to observed data. The DWQ model overestimates DO
throughout the creek due to poorly calibrated hydraulic parameters and an overestimation of reaeration.
The model predicts that the DO standard is met throughout the length of the creek, but the observed data
show that the standard was not met over at least 8.5 miles.
Data DWQ Model
• Observed -Original Standard
8
7-
6-
J
E 5
♦
>,
4
• ••
0
m
0 3
u)
0
0
2
1-
♦ ♦
Distance Downstream of WWTP (miles)
Figure 25. Comparison of DWQ QUAL2E Model to Observed Data
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
4 Stream Reconnaissance
January 20, 2006, Tetra Tech visited 11 sites on Rich Fork Creek and one site on each of the three major
tributaries (Figure 26). Four sites were upstream of the wastewater treatment plant and seven sites were
downstream. The purpose of the trip was to gather general information on channel structure, substrate
composition, and source loads that may not have been accounted for in the original DWQ model and to
identify potential reasons for the 1 to 2 mg/L drop in DO downstream of the plant. The water quality
analyst for the plant, Frank Skee, accompanied two Tetra Tech associates for the majority of the site
visits.
The weather was clear and unseasonably warm for this time of year. Flow at the plant upstream of the
discharge was estimated to be 30 cfs based on fraction of flow discharged from the plant and a Manning's
equation estimate. Application of the drainage area ratio to gaged flows on Abbotts Creek yields an
estimate of 6 cfs.
The following general observations were made:
• Substrate composition became finer in the downstream direction.
• Historic and active sand dipping operations have formed three large pools that appear stagnant
during low flows. The Highway 109 pool is approximately 1,500 feet in length; the Ball Road
and Kanoy Road pools are approximately 500 feet in length. On January 20, 2006, the water
widths at each pool ranged from 50 to 100 feet and the depths appeared to be 4 feet or greater.
The storage capacity of the pools increases travel time through these segments allowing for
increased settling and accumulation of organic material.
• Accumulations of organic material were seen in each of the three pools. The depth of material in
each pool decreased further downstream of the plant.
• With the exception of the three pools, the channel is fairly stable and has access to a broad, well
vegetated floodplain. Observed water width during the field reconnaissance was 30 to 40 feet and
the depth was 1 to 2 feet.
• Most of the adjacent lands were forest, pasture, and low density residential lots. No row crops
were seen from the car. Cattle access was not evident at any of the sites visited.
• The tributaries that drain the urban areas from the eastern portion of the watershed are well
connected with their floodplains. Substrate is similar to that seen in the sites upstream of the
wastewater treatment plant on Rich Fork Creek. No accumulations of organic material were seen.
• Heavy sediment deposition and large sand bars were seen at all sites.
Figure 27 through Figure 33 show examples of these observations. A complete set of photos and field
notes are included in Appendix A.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
• Field Reconnaissance Sites
A/ Streams
n HUC Boundary
Rich Fork Creek at High Point Road
Rich Fork Creek at Chesnut Street
Rich Fork Creek at Lexington Avenue
Rich Fork Creek at 20 Ft. Upstream of Discharge
Rich Fork Creek at Highway 109
Rich Fork Creek at Midway School Road
Rich Fork Creek at Ball Road
Rich Fork Creek at Kanoy Road
Rich Fork Creek at Evans Road
Rich Fork Creek at Old Highway 29
3
0
3
6 Miles
s Road
urton Road
one Road
Figure 26. Sites Visited During January 2006 Field Reconnaissance
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 27. Example of Floodplain Along Unmined Section of Rich Fork Creek,
Near Midway Road
Figure 28. Example of Sediment Deposition in Rich Fork Creek
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
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Figure 29. Comparison of Substrate Composition in Unaltered and Sand Dipped Portions of the
Channel, Respectively
Figure 30. Comparison of Organic Layer at Highway 109 Pool (- 1 inch), Ball Road Pool
(-1/4 inch), and Kanoy Road Pool (-1/8 inch), Respectively
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
March 2006
Figure 31. Sand Dipping Crane at Active Mining Site Upstream of Highway 109
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr.
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Figure 32. 1998 Orthophoto Showing Change in Channel Width Upstream and Downstream of
Ball Road Bridge
Figure 33. Comparison of Stream Channel Upstream and Downstream of Ball Road Bridge,
Respectively
Th
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
5 Additional Modeling Analysis and Evaluation of
Assimilative Capacity
Tetra Tech created a model run to simulate the channel and pools as seen during field reconnaissance and
to incorporate more recent data concerning BOD decay, headwater quality, and plant effluent quality.
Data to calibrate hydraulic equations were not available. The velocity was fixed such that the residence
time observed during the Black & Veatch time of travel study was replicated at low flow (6.5 days).
Velocity, depth, and width were fixed for the pools and channel as summarized in Table 7.
Table 7. Fixed Velocities, Widths, and Depths for the Pools and Unaltered Channels of Rich
Fork Creek
Velocity (fps)
Depth (ft)
III
Width (ft)
Type
Pool
0.02
4
85
Unaltered Channel
0.12
2
28
Review of the original DWQ model showed that the reaeration options were overestimating reaeration in
most of the simulated reaches and were not consistent with guidelines provided by EPA concerning the
applicability of reaeration methods based on velocity and depth constraints (Section 3.2). Therefore,
Tetra Tech updated the reaeration options for this run and assigned QUAL2E option 4 (Owens method) to
the unaltered segments and QUAL2E option 3 (O'Connor and Dobbins) to the pooled segments.
Based on a long-term BOD study performed by DWQ in 1996, Tetra Tech updated the ratio of BOD
ultimate to BOD5 to 5. The BOD bottle decay rate during this test was 0.03/day. Tetra Tech applied the
Bosco equation (USEPA, 1985) to estimate instream decay rates.
The SOD rates were also changed. The original model had lower SOD rates in the first six miles
downstream of the plant, followed by a 2 to 2.5 fold increase in the lower four miles. Tetra Tech set the
SOD to a constant rate of 0.25 g/ft2/d which is at the upper end of the range observed in the Yadkin Basin
(Reid, 2005). SOD rates were left constant because of observed organic material and the fact that no
recent SOD monitoring data were available to spatially vary the load.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
September 20, 2005 was used as the simulation day because of low flow conditions and quantity of water
quality observations. Table 6 in Section 3.2 lists the headwater and effluent quality assumptions. Figure
34 compares the observed DO concentrations to the low flow simulation set up by Tetra Tech. The curve
fits well in the upper five miles but tends to overestimate DO in the lower five miles. This may be due to
incorrect hydraulic functions or poorly estimated SOD rates. Neither of these parameters can be
improved without a detailed field monitoring study.
Tetra Tech low flow run • Observed
7
6
J
•
al
c
c
♦ �Y
ai
x
0
-
a)
0
w
C
0
1
0
IT -II II IIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIII
0 . 0 \ Co N Co . 0 \ CoN 0 N CoN 0 N 6 N
�.
0. 0. ,N. A,. r1,. n). n). IX. �. 4). 43. 0. 0. A. ,\. cb. cb. 0. �. N0.
1 1 Distance (miles)
Figure 34. Comparison of Tetra Tech Low Flow Simulation to Observed Dissolved Oxygen on
September 20, 2005
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
After Tetra Tech developed a reasonable model that included the three pools, several scenarios were run
to determine what changes would be required to bring the DO above the standard during low flow
conditions. Figure 35 shows the effect of restoring the pools to their natural channel with and without a
reduction in ultimate BOD concentration from the plant. On September 20, 2005 the ultimate BOD
concentration is assumed to be 10 mg/L based on daily reported effluent data for BOD5 and a ratio of
BOD ultimate to BOD5 of 5. The reduced scenario assumes a 50 percent reduction in BOD ultimate
concentration to 5 mg/L. Restoring the ponds without altering the plant effluent quality only moved the
location of the DO sag. After approximately four miles downstream from the plant, the simulated curves
converge at the sag concentration of 4.6 mg/L. Reducing the ultimate BOD load from the plant by one-
half results in a DO sag of 4.7 mg/L.
With SOD 0.25, BODult 10
pools, mg/L
Restore SOD 0.25, BODult 10
7
pools, mg/L
Restore pools, SOD 0.25, BODult 5 mg/L
♦ Observed
6
J
5
E
c
curs, 4
•
x
0
>
0
tn
0
0
1
0
„, F111[1]'[1'[1] [1]'[1]'[1 111111[11]'[1],,,,,,]1[1]'[1]'[111
t•t•Cat•6 t•0 l•Co N t•Co t•CoN CoN COS
Distance (miles)
Figure 35. Impacts of Channel Restoration and WWTP BOD Load Reduction on Simulated
Dissolved Oxygen Concentrations in Rich Fork Creek
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 36 shows the impacts of reducing the SOD rate by 20 percent with and without a reduction in the
ultimate BOD load. The standard of 5 mg/L DO is met when the SOD rate is reduced to 0.2/d with and
without the reduction in BOD load.
SOD 0.20, BODult 5
-Restore pools, mg/L
Restore SOD 0.20, BODult 10
pools, mg/L
Restore SOD 0.25, BODult 10
pools, mg/L
♦ Observed
6
J
5
E
_
a) 4
♦
x
O 3
d
0 2-
N
N
G
1-
0
, ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
O^ O' N' ^6 ti ti� �^ �� Do D<6 h^ 43'o O^ 66 A • A • O^ O� O^ O� No.
Distance (miles)
Figure 36. Impacts of SOD and BOD Load Reduction on Simulated Dissolved Oxygen
Concentrations in Rich Fork Creek
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Under the simulated low flow condition, the SOD rate appears to be the most important factor in
improving DO conditions in Rich Fork Creek besides restoring the stream channel configuration. Tetra
Tech evaluated plant effluent BOD loads to determine if process disturbances, such as a high runoff
event, would result in reduced effluent quality that may lead to a build up of oxygen demanding wastes in
the stream. Figure 37 shows the monthly BOD5 load compared to the maximum permitted load based on
a permitted flow rate of 6.2 MGD and BOD5 concentrations of 5 mg/L in the summer months and 10
mg/L in the winter months. The monthly BOD5 loads discharged by the plant are within the maximum
permit limits 93 percent of the time.
700
600
500
i
400
0 300
m
200
100
—Average Monthly Load —Monthly Permitted Load
7
_L__
0 1
Jan-97 Feb-98 Mar-99 Apr-00 May-01 Jun-02 JuI-03 Sep-04 Oct-05
Figure 37. Comparison of Monthly BOD5 Load to Permitted Monthly Load
A 20 percent reduction in the SOD rate results in DO concentrations above the standard even during
critical conditions. It is feasible that a 20 percent reduction could be achieved because: 1) the assumed
existing SOD rate is at the high end of the range observed in the Yadkin Basin, 2) the altered hydrology
of the pools appears to cause an accumulation of organic material, and 3) improvements in plant effluent
quality will reduce the amount of organic material available for decomposition.
Because the low flow simulation has fixed velocities and cross sections, it is not possible to simulate
other flow conditions. Hydraulic studies and cross section measurements will be required to obtain the
parameters necessary to simulate a range of flows with an updated QUAL2E model.
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6 Overall Conclusions and Recommendations
The scoping analysis performed by Tetra Tech identifies several factors that will likely influence future
permitting and wasteload allocations for the High Point Westside facility's discharge to Rich Fork Creek.
6.1 POTENTIAL FOR INCREASED WASTE FLOWS FROM WESTSIDE WWTP
Tetra Tech's evaluation of the current model used for High Point's wasteload allocation revealed several
areas where model setup and calibration could be improved to better represent assimilative capacity in
Rich Fork Creek. A field reconnaissance of Rich Fork Creek in January 2006 revealed altered hydrology
due to instream sand mining at three locations. The resulting pools are accumulating noticeable deposits
of organic material and may be increasing the overall sediment oxygen demand in the creek. Tetra Tech's
low flow version of the QUAL2E model for Rich Fork Creek indicates that SOD is driving DO below the
standard during low flow, high temperature conditions. The modeling indicates that a 20 percent
reduction in SOD would likely improve conditions such that the DO standard is met. Because the
assumed SOD rate is at the high end of the range observed in other streams in the Yadkin Basin, a 20
percent reduction seems feasible if the pools are removed and the effluent quality is further improved.
Under current conditions, it is not likely that DWQ will grant permission to Westside WWTP for
increased waste flows, even with improved effluent quality. Observed data and the Tetra Tech low flow
model indicate that the assimilative capacity of the creek is currently exceeded. However, stream channel
restoration to remove the pools coupled with improvements in plant effluent quality could result in
reduced SOD rates and DO concentrations above the standard even during critical conditions. If this
occurs, assimilative capacity for High Point's discharge would be restored.
6.2 RECOMMENDED NEXT STEPS
In light of the scoping analysis findings, Tetra Tech suggests the following steps be taken to determine if
plant improvements and stream restoration will effectively increase the assimilative capacity of the creek.
1) Meet with DWQ to review the scoping analysis results and to confirm the recommended path
forward. Tetra Tech proposes that two separate field studies be conducted to gather data
concerning travel times, kinetic parameters, and additional DO monitoring. These studies are
discussed in more detail in Appendix B. The first study should be conducted prior to altering the
stream system so that the low flow version of the model can be validated with field parameters.
This study will focus on the parameters carrying the greatest uncertainty such as the time of travel
through the pools and the SOD rates in and out of the pools. The second study should occur after
the plant improvements and stream restoration are complete and the stream channel and substrate
composition have reached equilibrium. Because the ensuing model may be used to determine the
wasteload allocation of the plant, a complete field study including time of travel, cross section
measurements, and all dissolved oxygen balance parameters should be performed. The remaining
steps outline how monitoring and modeling could proceed to accomplish the city's objectives.
2) Conduct Phase 1 of monitoring to confirm the hydraulic assumptions of the low flow version of
the QUAL2E model and determine the impacts of the pools on DO:
a. Perform a time of travel study during low flow conditions to confirm the travel time
through the pools and the unaltered sections of the channel
b. Collect SOD measurements upstream of the plant, downstream of the plant in each pool,
and downstream of the plant in the unaltered sections between the pools.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
c. In addition to the current Westside general water quality monitoring locations, monitor
the upstream, downstream, and middle sections of each pool.
3) Update the low flow version of the QUAL2E model with field observed values for residence time
and SOD rates to validate or refine the scoping analysis conclusions.
4) Hold a meeting with DWQ to review the monitoring and updated modeling results, and to get a
regulatory opinion on restoring the stream channel to improve assimilative capacity.
5) Work with regulatory agencies to obtain necessary permits for stream restoration and with
landowners to obtain conservation easements to prevent further sand mining along Rich Fork
Creek. Restore the three pools at Highway 109, Ball Road, and Kanoy Road.
6) After the pools are restored, periodically monitor the thickness of organic material deposited on
the substrate downstream of the discharge to determine if the system has regained equilibrium
under the restored flow regime.
7) After plant upgrades are complete and stream equilibrium is confirmed, conduct Phase 2 of
monitoring which should include updated time of travel estimates during low and average flow
conditions, cross section measurements at several locations, instream SOD measurements
upstream of the plant and at two or three locations downstream of the plant, parameters
describing the oxygen balance including reaeration estimates, nutrient transformations, and algal
kinetics, and long-term BOD estimates for the headwater, plant effluent, and selected downstream
locations. Continue monitoring general water quality at all Westside stations as well as the
restored segments.
8) Update the QUAL2E model for Rich Fork Creek to reflect channel restoration, plant upgrades,
and field study results. Reassess assimilative capacity of the stream based on model simulation
and observed data, and provide the model and results to DWQ for use in determining future
wasteload allocations.
In addition, the City of High Point should continue to identify and repair malfunctions of the sewer
collection system to reduce overall loading to the stream.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
7 References
Black & Veatch. 1987. Rich Fork Creek Water Quality Study. Prepared for City of High Point, North
Carolina; Davidson County, North Carolina; and North Carolina Department of Natural Resources and
Community Development.
DEM. 1989. Report File for the High Point Westside WWTP. Division of Environmental Management,
February 8, 1989.
NCDWQ. 2004. Total Maximum Daily Loads for Fecal Coliform for Rich Fork Creek and Hamby Creek,
North Carolina, Final Report April 2004. Prepared by North Carolina Depai indent of Environment and
Natural Resources Division of Water Quality.
Reid, Dianne. 2005. Personal communication with Alix Matos concerning measured SOD rates in the
Yadkin River Basin, email dated 12/15/2005.
Skee, Frank. 2006. Personal communication with Alix Matos concerning cracked sewer main at Chesnut
Street, 1/20/2006.
USEPA. 1985. Rates, Constants, and Kinetics Formulations in Surface Water Quality Modeling (Second
Edition). United States Environmental Protection Agency, Research and Development. Report
EPA/600/3-85/040, June 1985.
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Appendix A. Photos and Field Notes from January 2006 Field
Reconnaissance
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Appendix B. More Detailed Description of Field Studies
Recommended for Next Steps in Supporting Rich
Fork Creek QUAL2E Modeling and Wasteload
Allocation
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Appendix A. Photos and Field Notes from January 2006
Field Reconnaissance
a
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1 Introduction
Tetra Tech staff conducted a field evaluation of Rich Fork Creek in January 2006 to determine if any
additional physical factors, particularly those not already represented in the QUAL2E model, may be
contributing to the dissolved oxygen (DO) problems in the creek. Fourteen sites were visited, as shown in
Figure 1. Three were located on tributaries just upstream of their confluence with Rich Fork Creek. Four
sites were upstream of the Westside wastewater treatment plant, and seven sites were downstream.
• Field Reconnaissance Sites
Streams
HUC Boundary
Rich Fork Creek at High Point Road
Rich Fork Creek at Chesnut Street
Rich Fork Creek at Lexington Avenue
Rich Fork Creek at 20 Ft. Upstream of Discharge
Rich Fork Creek at Highway 109
Rich Fork Creek at Midway School Road
Rich Fork Creek at Ball Road
Rich Fork Creek at Kanoy Road
Rich Fork Creek at Evans Road
Rich Fork Creek at Old Highway 29
3
0
3
6 Miles
s Road
urton Road
one Road
Figure 1. Sites Visited During January 2006 Field Reconnaissance
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
At each site, observations of stream morphology were recorded, including the potential for streambank
erosion, floodplain access, and substrate composition. Approximations of water width and depth were
also noted. A narrow shovel with a one -foot long blade was used to extract substrate profiles beneath the
water surface and from adjacent banks.
The following general observations were made concerning the fourteen sites visited:
• Substrate composition became finer in the downstream direction.
• Historic and active sand dipping operations have formed three large pools that appear stagnant
during low flows. The Highway 109 pool is approximately 1500 feet in length; the Ball Road and
Kanoy Road pools are approximately 500 feet in length. On January 20, 2006, the water widths
at each pool ranged from 50 to 100 feet and the depths appeared to be 4 feet or greater. The
storage capacity of the pools increases travel time through these segments allowing for increased
settling and accumulation of organic material.
• Accumulations of organic material were seen in the substrate profiles taken from each pool. The
depth of material in each pool decreased with distance downstream from the plant.
• With the exception of the three pools, no major physical degradation was observed in any of the
stream channels — likely due to the connection of the channel to broad, well vegetated
floodplains. Above Hunts Fork Creek, the observed water widths were approximately 30 to 40
feet and the depths were 1 to 2 feet. Below Hunts Fork Creek, the water widths were
approximately 40 to 50 feet and the depths were 2 to 3 feet
• Most of the adjacent lands were forest, pasture, and low density residential lots. No row crops
were seen from the car. Cattle access was not evident at any of the sites visited.
• The tributaries that drain the urban areas from the eastern portion of the watershed are well
connected with their floodplains. Substrate is similar to that seen in the sites upstream of the
wastewater treatment plant on Rich Fork Creek. No accumulations of organic material were seen.
• Heavy sediment deposition and large sand bars were seen at all sites.
The following sections of this Appendix present the digital photos and field notes taken at each site. As a
matter of convention, descriptions of "left" and "right" are based on a downstream facing view.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
2 Site 1: Rich Fork Creek at High Point Road
The following general observations were made at Site 1:
• Water was approximately 4 feet wide and 4 inches deep. Good riffle movement. Algae growing
on rocks. Water was clear. Banks are slightly entrenched but well vegetated and appear stable.
• Substrate comprised of bedrock, cobbles, gravel, and sand.
• Substrate sample showed mix of sand and gravel, no color changes, no accumulation of organic
material.
• Bottom plants growing in sand. Green algae abundant on larger substrate, indicating that high
flows rarely mobilize the streambed substrate.
• No pools, but consistently spaced riffles.
• Adjacent cleared areas are grassed.
• No significant sand bars or channel erosion.
• Presence of Ephemeroptera species (mayflies) and Trichoptera species (caddisflies) under larger
rocks in the streambed. Many of these species are sensitive to water quality and habitat
degradation, so their presence indicates good habitat and water quality.
• The observed reach has only limited restoration potential, but riparian planting would be feasible
if elevated water temperatures are deemed a problem.
• An adjacent landowner stated that fields are present upstream of this site, but he had no
knowledge of their use as pasture or of the presence of cattle in the stream. He has worked
adjacent to the stream for one year and had not seen high flows, although the he noted that the
stream had essentially dried up during the 2005 summer.
Figure 2 through Figure 13 illustrate these observations. Specific notes follow each photo.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 2. Substrate at Site 1
Course sand and gravel substrate. Well vegetated banks.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 3. Rich Fork Creek at Site 1, Facing Upstream
See large cobble, well vegetated banks. Access to floodplain. Regularly spaced riffles.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 4. Substrate sample at Site 1
Substrate composition over approximately 1 foot of depth: course sand, gravel, no change in color, no
organic layer on surface.
Figure 5. Filamentous Algal Growth on Rocks in Stream at Site 1
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 6. Algal Growth on Rocks at Site 1
Figure 7. Algal Growth on Rocks at Site 1
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Figure 8. Algal Growth in Stream
Picture clarity failed to show algal growth on substrate.
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Figure 9. Rich Fork Creek at Site 1, Facing Downstream
Good access to floodplain, vegetated banks with grass and small brush. Few trees and canopy
vegetation provide limited shading, thereby allowing for sunlight to elevate water temperatures.
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Figure 10. Rich Fork Creek Floodplain at Site 1
Access to floodplain, well vegetated banks with grass and small brush. Few trees and not much shading.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 11. Ephemeroptera species at Site 1
Figure 12. Ephemeroptera Species at Site 1
Top left specimen had gills on underside. Both specimens had three tails.
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Figure 13. Trichoptera and Ephemeroptera species at Site 1
Picture fails to clearly show specimens seen on underside of rock.
a
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
3 Site 2: Rich Fork Creek at Chestnut Street
The following general observations were recorded at Site 2:
• Sandy substrate. A few large boulders have algal growth.
• Thalweg is approximately 1 foot deep.
• Small gravel and sand deposition bars. Banks entrenched with some vegetation.
• Pool upstream is 2 to 3 feet deep.
• Water is approximately 16 feet wide. Banks are approximately 7 to 8 feet high. Steep with some
grass and tree roots.
• Instream erosion does not appear to be the significant source of sediment in the stream.
• Substrate sample comprised of sand on top 6 inches underlain by course sand on bottom 6 inches.
No change in color; no accumulation of organic material.
• Sandy substrate moving constantly under observed flow conditions..
• Saw no evidence of organic material or sludge at this site, though a leaky sewer pipe at Chestnut
Street allowed raw sewage into the stream during the summer of 2005 for weeks to months before
being detected (Frank Skee, 1/20/06).
• Trees on banks would provide approximately 75 percent cover during leaf out.
• During drive from Site 1 to Site 2, field team saw no cattle in fields or row crop agriculture, only
grass and pasture.
Figure 14 through Figure 20 illustrate these observations.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 14. Rich Fork Creek Facing Upstream at Site 2
See entrenched banks with good vegetation. Sand bar forming on left side.
Figure 15. Movement of Sandy Substrate at Site 2
Sandy substrate constantly moving. See sand ripples.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 16. View of Sand Bar at Site 2
Sand bar comprised of course and fine grained sand. Stream banks entrenched with some vegetation.
Figure 17. Entrenched Banks at Site 2
Banks are approximately 8 feet high. Elongated sandbar. Vegetated banks. Though this site does not
have easy access to floodplain, banks do not appear to be eroding significantly.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 18. Algal Growth on Rocks in Stream on Right Side of Channel
Picture fails to clearly show the algal growth.
Figure 19. Substrate Sample Extracted from Site 2
Deeper 6 inches (left side of shovel scoop in the figure) has course brown sand. Top 6 inches has finer
sand. Little color change. No accumulation of organic material.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 20. Algal Growth on Woody Debris at Site 2
Algae growing on fixed limb.
a
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4 Site 3: Rich Fork Creek at Lexington Avenue
The following general observations were made at Site 3:
• This site corresponds to YPDRBA site Q5750000 and is approximately 1.3 miles upstream of the
WWTP. The Westside WWTP also samples general water quality at this site on a routine basis.
• Sand bars are present. Eroded banks are steep but vegetated. Water is green and murky in the
pooled area formed behind old bridge abutment. This color was not evident at the other two sites,
but no pools were present there either.
• Substrate sample shows 6 inches of brown sand underlain by gray sand. No organic layer
present.
• Algae present. Attached plants growing on old bridge abutment.
• Water is about 18 feet wide and'/z to 1 foot deep on this day. More algae present here than at the
two upstream sites. Pool formed by abutment was approximately 3 feet deep.
• Noticeable sediment deposition on banks.
• Canopy cover would be approximately 50 percent during leaf out.
• Banks were approximately 5 feet high.
Figure 21 through Figure 28 illustrate these observations.
Figure 21. Sand Bar Formation at Site 3
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 22. Rich Fork Creek Facing Downstream at Old Bridge Abutment
Green murky water in pooled area. Deposition on left bank.
Figure 23. Substrate Sample at Site 3
Substrate sample has fine brown sand on top 6 inches underlain by course gray sand.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 24. Algal Growth in Pooled Area at Site 3
Pooled area formed by old road abutment.
Figure 25. Rich Fork Creek at Site 3, Facing Downstream
Banks show signs of erosion but not severe. Banks are well vegetated. A sand bar was forming on left
side of channel downstream of the old abutment.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 26. Sand Bar Formation at Site 3, Facing Downstream
Figure 27. Rich Fork Creek at Site 3, Facing Upstream
Sand bar formation on the right bank; deposition on top of the left bank.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 28. Rich Fork Creek at Site 3, Facing Downstream
Well vegetated banks. Sand bar formation on left.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
5 Site 4: Rich Fork Creek Twenty Feet Upstream
of WWTP Discharge
The following general observations were noted at Site 4:
• This site corresponds to the Westside monitoring station CHP1 which is 20 feet upstream of the
WWTP discharge.
• CHP 1 is sampled from a sampling bridge when water is accessible.
• Width of water on this day was approximately 30 feet; depth was 'V2 to 1 foot.
• Substrate is primarily sand and course sand. Substrate sample had top 8 inches of brown course
sand similar to upstream. However, deeper 4 inches of sand was gray. A second sample from an
adjacent bank had 12 inches of brown sand underlain by gray sand. No accumulations of organic
material.
• Steep banks with some vegetation. Banks not eroding significantly; erosion does not appear to be
the source of sediment in the stream.
• Banks are silty but channel substrate is not (similar to Site 3 at Lexington Avenue.)
• Saw mussel shells in the stream.
• Began to notice fallen trees in the channel when looking upstream. Trees were leaning and
falling in because of channel movement in the sandy substrate.
• Near full canopy at leaf out.
• Can smell plant effluent. Effluent has a light green color and mixes in fairly quickly with
streamflow on this day. Substrate taken from mixing zone is similar to that seen upstream of the
discharge.
Figure 29 through Figure 43 illustrate these observations.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 29. Westside Sampling Bridge at Site 4
Water quality samples are taken from the downstream,left corner of bridge when water is present.
Figure 30. Facing Opposite Bank from Sampling Bridge at Site 4
Green tint in pooled areas — approximately 2 ft deep.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 31. Rich Fork Creek Facing Upstream at Site 4
Banks are vegetated with trees, but groundcover and shrubs limited. Sand bars forming.
Deposition on top of left bank.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 32. Facing Downstream at Site 4
Large sand bar forming on right bank. Sandy substrate. Well vegetated floodplain..
Figure 33. Insertion of Shovel at Site 4
Shovel easily pushed through two feet of unconsolidated substrate.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 34. Deposition of Silts on Left Bank
Fines evident on banks, but not in stream.
Figure 35. Facing Downstream from CHP1 Sampling Bridge
Sampling of Westside WWTP Effluent as part of the Westside instream monitoring program.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 36. View of Channel Substrate Upstream of the Plant Discharge
Three distinct layers seen in substrate: top 4 inches is course brown sand, middle 4 inches is light brown
sand, and deepest four inches is gray sand. No organic material present.
Figure 37. Shovel Sample Taken from Adjacent Bank
Material taken from bank has more silt and clay than instream sample. Top foot extracted has brown
color; gray material present below.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 38. Sandy Substrate at Site 4
Figure 39. Westside WWTP Effluent Discharge
Effluent has green tint compared to streamflow.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 40. Rich Fork Creek Below Effluent Discharge
See effluent discharge moving downstream. Not yet completely mixed.
Figure 41. View of Effluent Discharge Mixed with Streamflow on Bank Opposite Discharge
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 42. Sand Bar Formation on Right Bank Downstream of Effluent Discharge
Substrate sample appeared the same as CHP1: brown sand on top underlain by gray sand. No organic
accumulation on substrate. Leaf litter present in stream to the right of field technician.
Figure 43. Rich Fork Creek Downstream of WWTP Discharge, Facing Downstream
Floodplain well vegetated. Sand bars prevalent; sediment deposition on banks.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
6 Site 5: Rich Fork Creek at Highway 109
The following general observations were noted at Site 5:
• The Highway 109 bridge is the sampling site for Westside instream station CHP3. This site is
approximately 0.3 miles downstream of the WWTP discharge.
• This site was visited twice. The downstream section was visited during the middle of the day.
The upstream section was visited in the early evening after finding sand mining equipment at
other locations on Rich Fork Creek.
• There is an ongoing construction project at this site for road and bridge widening.
• Initial site visit, downstream of Highway 109 bridge:
o Water is green, pooled, and flat. Slow moving. Water is approximately 50 feet wide on
day of reconnaissance and 3 to 5 feet deep (depth guessed because bottom could not be
seen). Banks are approximately 8 ft higher than water surface.
o Can still smell plant effluent. No DO problems detected here in the summer of 2005
from Westside instream monitoring, but that may be due to high DO concentration in
WWTP effluent.
o Substrate had approximately one inch of organic material underlain by gray, cohesive
sand. Substrate composition is completely different compared to other sites upstream of
the plant.
• Second site visit, upstream of Highway 109 bridge:
o Walked upstream behind road construction project. Saw crane with dipping bucket,
recent tire tracks, scrape marks in stream. Instream mining has formed a pool
approximately 1500 feet long with an estimated depth of 3 to 5 feet.
o Was not able to sample substrate with shovel, but organic layer was visible from stream
bank.
o Field technicians noted that though it seems likely that the organic layer would be
removed during excavation along with the sand, this layer was easily washed off during
substrate sampling at other sites. Therefore, it is expected that much of the organic
material is suspended during dredging and is re -deposited on the pool bottom.
Accumulations of organic material are likely due to low velocities in pooled areas as well
as washoff during sand removal.
Figure 44 through Figure 56 illustrate these observations.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 44. Sample of Substrate Taken at Site 5
Layer of brown organic material underlain by gray cohesive sand. Completely different substrate
compared to other sites. Due to pool depth and limited access to thalweg, this sample was taken at the
toe of the right bank and may not represent substrate along the pool bottom.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 45. Sample of Substrate Taken at Site 5
Note consistency of organic material pulling away on top left of sample. Finger smudge on right side of
sample.
Figure 46. Rich Fork Creek at Site 5, Facing Downstream
Water is estimated as 3 to 5 feet deep and approximately 50 feet wide. Water has green tint. Banks are
well vegetated, but entrenched.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 47. Rich Fork Creek from Highway 109 Pool, Facing Upstream
Water has murky tint.
Figure 48. Sand Mining Equipment Located Upstream of Highway 109 Bridge
Crane parked in front of creek. Has same type of dipping bucket found on Ball Road crane.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 49. Tire Tracks Behind Sand Mining Crane
Due to precipitation prior to field evaluation, tracks indicate that crane was recently in use.
Figure 50. Residual Sand Pile at Mining Site Adjacent to Rich Fork Creek
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 51. Recently Mined Section of Rich Fork Creek Above Highway 109
Scrape marks evident on opposite bank from sand dipping operation.
Figure 52. Rich Fork Creek at Sand Mining Operation, Facing Upstream
Excavated material pulled up left side of channel.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 53. Sand Mining Operation Adjacent to Rich Fork Creek, Facing Upstream
Disturbed area extends back to tree line. Recent tire tracks evident.
Figure 54. Sand Mining Operation Adjacent to Rich Fork Creek, Facing Downstream
Looking downstream toward bridge construction at Highway 109. Water pump with truck filling apparatus.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 55. Excavated Bank on Rich Fork Creek, Facing Upstream
Figure 56. Recent Tire Tracks at Sand Mining Operation Adjacent to Rich Fork Creek
Track patterns indicate use of machinery to load dredged sand into trucks for transport.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
7 Site 6: Rich Fork Creek at Midway School Road
The following general observations were made at Site 6:
• Site 6 corresponds to YPDRBA site Q5780000 and is also sampled routinely by the Westside
WWTP. This site is located approximately 1.4 miles downstream of the Westside facility.
• Stream geometry has recovered compared to pooled reach at Highway 109.
• Substrate is sandy. Algae evident on fixed woody material.
• Substrate sample has brown sand underlain by gray sand. No accumulation of organic material.
• Water is approximately 45 feet wide and 1 to 2 feet deep.
• Banks are steep but vegetated (approximately 3 feet high). Stream has access to a broad
floodplain.
• Mussel shells present in stream.
• Fewer fallen trees in channel. Pools present.
• Canopy cover approximately 75 to 100 percent during leaf out.
Figure 57 through Figure 60 illustrate these observations.
Figure 57. Wetland Floodplain Adjacent to Rich Fork Creek at Site 6
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 58. Rich Fork Creek at Site 6, Facing Upstream
Water is 1 to 2 feet deep with green color. Banks are well vegetated. Broad floodplain.
Figure 59. Rich Fork Creek at Site 6, Facing Downstream
Water is shallower than in upstream direction.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 60. View of Floodplain at Site 6
Water is deeper along sides of channel due to sediment deposition along centerline.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
8 Site 7: Rich Fork Creek at Ball Road
The following general observations were made at Site 7:
• This site corresponds to the Westside instream monitoring site CHP4 and is approximately 2.9
miles downstream of the plant discharge.
• Upstream of the Ball Road bridge, water is shallow and fast moving. Notice green color in
deeper waters. Lots of mussel shells. Water is approximately 4 inches deep in the center and
deeper on the sides. Deep pool on right side facing bridge (greater than 4 feet). Frank Skee says
large sand deposit in center of channel is from recent storm and field technician sank when
walking to get estimate of pool depth. Can still smell plant effluent.
• Substrate sample upstream of bridge is course sand only.
• Substrate sample downstream of bridge has a couple of inches of organic material underlain by
gray sand. Adjacent banks have the same sand, but top half is brown. Other than the color
change, the sand is the same.
• Field technician noticed bubbles when he lifted the shovel. Bubbles are also evident in
undisturbed areas of the pool. Frank Skee says bubbles are prevalent in summer months.
• Water is 75 to 100 feet wide downstream of the bridge. Very deep, dark green water. Visibility
approximately 2.5 feet; water depth approximately 5 feet. Depths at this site were estimated
using a weighted rope.
• Completely different channel geometry upstream and downstream of the bridge. Substrate
changes from brown sand to gray sand covered by organic material. Channel width increases
three fold. Depth increases from 1 to 5 feet.
• Downstream of the bridge water is much deeper and wider. Old crane with dipping bucket
parked next to stream. Appears that historic instream sand mining caused the change in channel
shape downstream of the bridge.
• Feasible restoration site in sand -mined pool.
Figure 61 through Figure 71 illustrate these observations.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 61. Approaching Rich Fork Creek from Ball Road Bridge, Looking at the Main Channel
from the Right Bank (Flow is from Left to Right in the Figure)
See color change of deep side pool compared to shallow stream channel. Broad floodplain. Well
vegetated banks.
Figure 62. Standing on Ball Road Bridge, Facing Upstream
See sandy, mobile substrate. Water is shallow and fast moving, approximately 30 feet wide and 1/2 to 1
foot deep. Substrate sample was course brown sand throughout.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 63. Sand Dipping Crane Located Downstream of Ball Road Bridge Next to Rich Fork Creek
Water on downstream side is three times as wide and five times as deep compared to upstream reach.
Figure 64. Sand Dipping Bucket Attached to Crane
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 65. Substrate Sample Taken from Ball Road Pool
Substrate is course gray sand covered by 1 to 2 inches of organic material.
Figure 66. Sample from Adjacent Bank
Here there is at least 1 foot of brown sand above the gray sand. In the channel, only gray sand is
present.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 67. View of Rich Fork Creek at Ball Road Pool, Facing Upstream Toward Bridge
Figure 68. Channel Substrate in Ball Road Pool
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 69. Review of Rich Fork Creek Facing Upstream from Ball Road Bridge
Figure 70. Edge of Sandbar and Pool on Upstream Side of Bridge
It's possible that some dipping occurred on this side of the bridge to form this pool.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 71. Review of Downstream Section of Rich Fork Creek
Water is much wider and deeper downstream of crossing. Bubbles were observed rising to surface
(figure fails to clearly show bubbles in lower left quadrant of photo).
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
9 Site 8: Rich Fork Creek at Kanoy Road
The following general observations were made at Site 8:
• Site 8 corresponds to YPDRBA site Q5785000 and is also sampled routinely by the Westside
WWTP. This site is located approximately 3.9 miles downstream of the Westside facility.
• Stream not easily accessible upstream of the bridge.
• Looking a few hundred feet upstream of the bridge, the stream is fairly narrow and sinuous. The
banks are approximately 1 foot above the water surface, well vegetated, with mature trees.
• Just upstream of the bridge the stream is wide and deep. Even more so downstream of the bridge.
On the downstream side, the water surface was approximately 150 feet wide and 5 feet deep
(depth estimated as the bottom could not be seen). Banks are approximately 2 to 3 feet higher
than the water surface. Rooted plants present in pooled areas.
• Substrate sample from downstream section is about 6 inches of brown sand underlain by 6 inches
of gray sand. Not as much accumulation of organic material on the top layer. The organic
material is mixed in with sand over a depth of approximately 1/4 inch.
• Saw live mussels in downstream section.
• Feasible restoration of sand -mined pool.
Figure 72 through Figure 75 illustrate these observations.
Figure 72. Substrate Sample at Site 8, Sample 1
Substrate sample shows approximately 6 inches of brown sand underlain by gray sand. Some organic
material on top, though not clearly illustrated in the photo.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 73. Substrate Sample at Site 8, Sample 2
This photo does not show a vertical profile. The field technician skimmed the surface to view the organic
material and determine if it looked similar to that seen at the other pools. At this site the organic material
covers the top'/4 inch and is mixed with brown sand, as shown in the center sample. The left sample is
gray sand from a vertical profile in the stream. The right sample is gray organic matter taken from a bar in
the stream and appears to be decaying leaf litter.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 74. Rich Fork Creek Facing Upstream at Kanoy Road Pool
Water is approximately 150 feet wide and 5 feet deep in this pool. Wide, flat field on opposite bank looks
similar to Ball Road and Highway 109 mining operation sites.
Figure 75. Rich Fork Creek Facing Downstream From Kanoy Road Pool
It appears that the stream is reestablishing a more natural geometry. The depositional bar forming on the
right side of the channel is beginning to restrict flow to the left side only.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
10 Site 9: Rich Fork Creek at Evans Road
The following general observations were made at Site 9:
• Evans Road at Rich Fork Creek corresponds to the Westside instream monitoring site CHP5 and
is approximately 6.6 miles downstream of the WWTP. This site is downstream of the first major
tributary (Hunts Fork Creek) which has entered the system since Kennedy Mill Creek joined Rich
Fork Creek just upstream of Highway 109.
• The channel at Evans Road is more similar to the upstream sites compared to the pools. The
water is approximately 20 to 30 feet wide and 1 to 2 feet deep. The sandy substrate is visible
from the bridge. Waters in deeper areas have a green color and are approximately 3 feet deep.
Lots of woody debris in the channel downstream of Evans Road. Water is moving, but is fairly
deep.
• Banks are 2 to 4 feet above water surface with some vegetation. Noticeable sand bar deposition.
• Substrate sample is comprised of brown sand with a layer of organic material on top (less than
1/8 inch).
• Upstream of the bridge, shovel sample has more gray sand, but less of the accumulated organic
material. Water moves faster on the upstream side.
• Good condition riparian buffer.
Figure 76 and Figure 77 illustrate these observations.
Figure 76. Rich Fork Creek at Evans Road, Facing Upstream
Broad floodplain, well vegetated banks. Water has green color in deeper areas. Sand bar was forming
along the left side of channel.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 77. Rich Fork Creek at Evans Road, Facing Downstream
Well vegetated banks. Water is pooled behind woody debris.
a
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
11 Site 10: Rich Fork Creek at Old Highway 29
The following general observations were made at Site 10:
• Site 10 corresponds to YPDRBA monitoring site Q5790000 which is approximately 9 miles
downstream of the WWTP. This site is also monitored by the Westside facility for general water
quality parameters.
• Water at this site was approximately 50 feet wide and 3 to 4 feet deep on the day of
reconnaissance. Bottom width of channel is approximately 80 feet. Large sand bars forming.
Entrenched banks (3 to 4 feet above water surface) with vegetation. Water has green color.
• First substrate sample had 1/8 inch accumulation of organic material followed by 2 inches of
brown sand underlain by gray sand.
• Lots of mussel shells present.
• Second substrate sample had no accumulation of organic material and was comprised of 6 inches
of brown sand underlain by 6 inches gray sand.
• Bubbles were noted rising to surface.
Figure 78 and Figure 79 illustrate these observations.
Figure 78. Rich Fork Creek at Site 10, Facing Upstream
Broad, well vegetated floodplain. Water is approximately 50 feet wide and 3 to 4 feet deep.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 79. Rich Fork Creek at Site 10, Facing Downstream
Stream is much wider just downstream of the bridge, but no evidence of historic sand mining.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
12 Site 11: Payne Creek at Hanes Road
The following general observations were made at Site 11:
• Payne Creek joins Rich Fork Creek between Site 3 and 4.
• Field technicians visited Payne Creek just upstream of its confluence with Rich Fork Creek.
• Payne Creek drains a significant fraction of the urban area in this watershed based on the 1992
NLCD land use coverage as discussed in the main report.
• Channel geometry and substrate look similar to sites on Rich Fork Creek above the WWTP and
sand mining operations.
• Water is approximately 10 to 12 feet wide and to 1 feet deep upstream of bridge and 12 to 15
feet wide and 8 inches to 1 foot deep on downstream end.
• Vegetation and litter are present on the top and sides of the banks.
• Large sandbar forming downstream of the bridge.
• The right side of the channel downstream of bridge has been stabilized with grass and large rocks.
• Substrate sample has brown sand underlain by light gray sand — not dark gray as on Rich Fork
Creek. No accumulation of organic material. Substrate does have some fine silts, but they are
not as cohesive or as dominant as in Rich Fork Creek.
Figure 80 and Figure 81 illustrate these observations.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 80. Payne Creek at Site 10, Facing Upstream
Well vegetated banks with a broad floodplain. This stream is in much better shape than expected given
the large portion of urban area in headwaters.
Figure 81. Payne Creek at Site 10, Facing Downstream
Large sand bar forming on left bank. Right bank required stabilization to protect adjacent fence.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
13 Site 12: Kennedy Mill Creek at Burton Road
The following general observations were made at Site 12:
• This site is on Kennedy Mill Creek just upstream of its confluence with Rich Fork Creek. This
creek drains a large portion of urban area according to the 1992 NLCD land use coverage as
discussed in the main report.
• Channel bottom is sand and course sand with some gravel. Water is approximately 10 to 15 feet
wide and'h to 1 foot deep.
• Substrate sample is comprised of brown sand with some gray streaks. One of three samples had 6
inches of brown sand underlain by 6 inches of gray sand. No accumulation of organic material.
• Broad, well vegetated floodplain.
Figure 82 and Figure 83 illustrate these observations.
Figure 82. Kennedy Mill Creek at Site 12, Facing Upstream
This creek has well vegetated banks and an accessible floodplain. Expected to see some degradation
given the amount of impervious surface in the upstream areas, but stream appears stable.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Figure 83. Kennedy Mill Creek at Site 12, Facing Downstream
Stream has well vegetated banks and access to floodplain. Sand bars forming.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
14 Site 13: Hunts Fork Creek at Stone Road
The following general observations were made at Site 13:
• This site is on Hunts Fork Creek just upstream of the confluence with Rich Fork Creek. This
creek drains a large portion of urban area according to the 1992 NLCD land use coverage as
discussed in the main report.
• Heavy sediment deposition in stream. One of the four box culverts under the road is almost
completely filled in with sand.
• Large sand bars are spaced in an alternating pattern down the channel and are reestablishing
sinuosity. No significant stream bank erosion at this site. Banks are well vegetated. Water is
approximately 20 feet wide and foot deep.
• There is a large wetland area on the left side of the channel which is separated from the channel
by a berm. May have historically been straightened with dirt placed on left bank.
• Substrate sample has brown sand underlain by a mixed layer underlain by a gray layer. Color
change does not have the sharp contrast seen at the Rich Fork sites and no accumulation of
organic material.
Figure 84 illustrates some of these observations.
Figure 84. Hunts Fork Creek at Site 13, Facing Downstream
Formation of alternating sand bars in stream is reestablishing sinuosity. Floodplain is well vegetated.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
Appendix B. More Detailed Description of Field Studies for
Recommended Next Steps in Supporting Rich Fork
Creek QUAL2E Modeling and Wasteload Allocation
El
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
1 Phase 1 Confirm Impacts of Pools
The objective of the first phase of monitoring is to verify the time of travel and sediment oxygen demand
(SOD) rates assumed in Tetra Tech's low flow version of the QUAL2E model as well as to observe DO
trends along the lengths of each of the three sand -mined pools.
1.1 MONITORING OBJECTIVES
• Obtain flow and velocity measurements to verify the QUAL-2E hydraulic components and
provide a basis for predicting stream reach velocities in Rich Fork Creek in both the pooled areas
and the unaltered sections of the channel during low flow.
• Continue to monitor general water quality parameters at the eight Westside instream monitoring
sites.
• Sample water quality in the three pools to measure DO concentrations in the slower moving
sections of the creek.
• Collect measurements of SOD from upstream of the wastewater treatment plant and downstream
of the plant in both the pooled and unaltered sections of the channel to accurately represent the
spatial variability of the demand.
1.2 SAMPLING COMPONENTS
Three primary monitoring components are required to meet the objectives of the monitoring plan: 1) time
of travel study, 2) general water quality characterization, and 3) sediment oxygen demand measurements.
1.2.1 Time of Travel Study
A time of travel study is needed to differentiate the residence times of each pool from the unaltered
sections of the channel Streamflow and dye studies will be performed to verify stream velocities and
travel times used in the low flow version of the QUAL2E model. Distribution of dye concentrations will
help calculate longitudinal dispersion, and peak -to -peak time will support velocity estimates.
The time of travel study should be conducted during summer low flow as close to or at 7Q10 critical
conditions. The timing of these studies will require that no significant rainfall events (> 0.5 inch) have
occurred in the previous seven days and that the creek has reached steady state flows during the sampling
period. Streamflow should be measured on the same days as dye studies are performed. Additional cross
section measurements should also be taken to update the previous sections and to ensure accurate
representation of sand mine pool versus natural stream channel reaches.
The initial dye injection point will be at the WWTP discharge location. Dye concentrations should be
monitored upstream and downstream of each pond. This will allow time of travel estimates through each
pond as well as through the connecting reaches.
1.2.2 General Water Quality Characterization
In addition to the instream sampling collected by the Westside plant, general water quality parameters
(temperature, pH, conductivity, DO) should be measured during critical conditions at the upper, middle,
and downstream sections of each pond. Sampling events should correspond to days of Westside instream
sampling so that a complete DO profile is collected downstream of the plant. At least two sampling
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
events during critical conditions are recommended to capture representative profiles. Sampling will be
performed using handheld instruments and all pertinent data will be recorded in a field log. This
sampling will be used to characterize the overall water quality in the ponds compared to the rest of the
system.
1.2.3 Sediment Oxygen Demand Measurements
SOD is an important parameter in the Rich Fork Creek model, but there is uncertainty in how to represent
SOD throughout the downstream reach. Based on visual inspection of channel substrate in January 2006,
it is expected that SOD rates may vary with the amount of organic material layering the substrate surface
along the length of the study reach. Because the low -flow version of the scoping model is so sensitive to
the SOD rate (a 20 percent reduction is predicted to result in compliance with the DO standard during
critical conditions), it is imperative that this parameter be defined as accurately as possible. SOD should
be measured upstream of the wastewater treatment plant, near the middle of each pool, in the unaltered
sections of the channel between the three pools, and downstream of the last pool.
1.3 MONITORING SCHEDULE
The preliminary field studies will ideally be carried out during the summer of 2006. The time of travel
study and collection of water quality data in the pools should be conducted during steady state flow
conditions near the 7Q10. The SOD testing apparatus may require water deeper than available in the
unaltered sections during low flow conditions and there must also be sufficient levels of DO available in
the water column. Therefore, SOD measurements should be taken at the lowest flows and highest
temperatures possible without interfering with the operation of the equipment.
For purposes of this study, no appreciable rainfall (> 0.5 inches) shall have occurred in the seven days
prior to the sampling events. Rainfall events which occur during the sampling events will be considered
on a case by case basis to determine whether they will interfere with the objectives of the study.
TETRATECH, INC.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
2 Support QUAL2E Model Recalibration
After the three pools have been restored and the plant has upgraded its facility to consistently discharge
high quality effluent, a full scale study will be needed to gather the information required to properly
calibrate and validate a wasteload allocation model reflective of the changed conditions. It is important
that the system reach equilibrium with the new flow regime and waste loads before monitoring begins.
Tetra Tech suggests that bank stability and substrate composition be monitored periodically at several
locations to determine if the system has reached equilibrium. Once stability is reached, it will be
appropriate to gather data for the wasteload allocation model.
2.1 MONITORING OBJECTIVES
• Obtain physical measurements to refine QUAL2E model input assumptions that represent Rich
Fork Creek channel width and depth under low flow conditions.
• Obtain flow and velocity measurements to calibrate QUAL2E hydraulic components.
• Continue to monitor general water quality parameters at the Westside instream monitoring sites.
• Collect general water quality data at the restored sites to assess impacts of restoration and provide
additional calibration data.
• Collect data to simulate full oxygen balance with QUAL2E.
• Collect field samples for lab analysis to characterize parameters associated with assimilative
capacity and initial modeling conditions at key locations.
2.2 SAMPLING COMPONENTS
Four primary monitoring components are required to meet the objectives of the full scale study:
1) hydraulic studies, 2) general water quality characterization, 3) DO balance analysis, and 4) detailed
water quality analysis.
2.2.1 Hydraulic Studies
Hydraulic studies are required to estimate the velocity of Rich Fork Creek throughout the study area
during low flow conditions. Physical channel measurements will be performed at transects throughout
the study area to determine the physical channel dimensions. Measurements should be made during low
flow conditions with water surface elevations recorded as well.
Additionally, two dye studies will be performed to characterize the flow/velocity relationships and
prediction of travel times. One study should be conducted near 7Q10 flow; the second should be
conducted during average flow conditions. Distribution of dye concentrations will assist in the estimation
of longitudinal dispersion; peak -to -peak time will support velocity estimates. Dye concentrations should
be monitored at the upstream and downstream end of each pool so that travel times through the pools and
each unaltered section can be accurately simulated.
The timing of these studies will require that no significant rainfall events (> 0.5 inches) have occurred in
the previous seven days and that the creek has reached steady state flows during the sampling period.
TETRATECH, INC.
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WQ Scoping Analysis for the High Point Westside Discharge to Rich Fork Cr. March 2006
2.2.2 General Water Quality Characterization
In addition to the sampling sites already monitored by the Westside WWTP, field sampling for general
water quality parameters should be performed in the middle of each restored segment. These sites should
be added to the Westside sampling protocol for at least one summer to accurately calibrate the wasteload
allocation model and to assess the impacts of the channel restoration.
2.2.3 DO Balance Analysis
The QUAL2E model requires estimates of reaeration rates, BOD decay rates, nutrient kinetics, algal
kinetics, and SOD by reach. Each of these components should be measured during low flow, warm
temperature conditions (when feasible) after the system has achieved equilibrium with the restored
channel
2.2.4 Detailed Water Quality Characterization (Intensive Survey)
Detailed intensive surveys are required to gain a more complete understanding of the water quality in
Rich Fork Creek during critical conditions. These surveys combine field observations with the collection
of water samples for analysis of parameters such as ammonia and biological oxygen demand to
characterize the complete cycle of oxygen demanding wastes. As with the hydraulic studies, timing will
require that no significant rainfall events (> 0.5 inches) have occurred in the previous seven days and the
creek has reached steady state flows during the sampling period. Two separate events should be sampled
for the purposes of calibrating and validating the wasteload allocation model.
Detailed water quality studies should be conducted on Rich Fork Creek just upstream of the WWTP
discharge, at the three YPDRBA sites, and on the WWTP effluent. The intensive surveys will consist of
field measurements as well as the collection of water quality samples for lab analysis (parameters to be
agreed upon with DWQ prior to sampling). In addition, one long-term sequential sample of DO midway
between the wastewater treatment plant and Hamby Creek will be used to characterize the diurnal
fluctuation of DO and pH downstream of the WWTP.
2.2.5 Monitoring Schedule
The full scale monitoring study for Rich Fork Creek should occur after the channel has been restored, the
plant has been upgraded, and the system is in equilibrium with the new flow regime. When feasible, all
studies should occur during summer low flow conditions with the exception of the second dye study
which should occur during average flow conditions (or at a significantly different flow level from the
critical flow). Two intensive water quality sampling surveys will be performed to collect data for the
calibration and validation stages of the model development.
The QUAL2E model predicts water quality under steady-state conditions. The monitoring events
specified in this plan are designed to capture instream water quality to aid in the calibration of the model
during baseflow conditions. For purposes of this study, no appreciable rainfall (> 0.5 inches) shall have
occurred in the seven days prior to the sampling events. Rainfall events which occur during the sampling
events will be considered on a case by case basis to determine whether they will interfere with the
objectives of the study.
TETRATECH, INC
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