19970722 Ver 1_Environmental Impact Statement_19970707

WATER QUALITY AND QUANTITY STUDIES
TO SUPPORT RANDLEMAN LAKE
ENVIRONMENTAL IMPACT STATEMENT
Prepared for
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
-0
BLACK & VEATCH
PROGRESS BY DESIGN
B&V Project No. 15849
Preliminary Issue: August 1990
Revised: December 1, 1990
Contents
I. Introduction ............................................... I-1
A. Background ............................................I-1
B. Objective and Scope ..................................... I-2
C. References ............................................I-4
H. Summary of Findings and Conclusions .......................... II-1
A. Downstream Flow and Reservoir Yield Analyses ............... II-1
B. Reservoir Trophic Level Evaluation ......................... II-2
C. Toxic Substances Evaluation .............................. II-3
III. Downstream Flow and Reservoir Yield Analyses ................. III-1
A. Reservoir Characteristics ................................ III-2
B. Reservoir Inflows ...................................... III-4
C. Randleman Yield ..................................... III-11
D. Flow Duration Analysis ................................ III-13
E. References ..................... III-18
IV. Reservoir Trophic Level Evaluation ........................... IV-1
A. Review of Existing Information ........................... IV-1
B. Nonpoint Source Loadings ............................... IV-3
C. Reservoir Response Model ............................. IV-11
D. Trophic State Parameters ................................ IV-19
E. References ......................................... IV-37
V. Toxic Substances Evaluation .................................. V-1
A. Survey of Existing Sources ................................ V-1
B. Identification of Problem Constituents ....................... V-5 _
C. Development of Toxic Substances Model .................... V-10
D. Model Results ........................................ V-12
E. References .......................................... V-17

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Contents (Continued)
Tables
III-1 Reservoir Characteristics III-3
III-2 Available USGS Streamflow Gaging Stations III-5
III-3 Subbasin Characteristics III-6
III-4 Monthly Water Use Demand Factors III-8
III-5 Initial Flow Calculations Equations III-9
III-6 Distribution of Flow Differences III-11
III-7 Allocation of Randleman Lake III-14
III-8 Randleman Lake Water Balance Following page III-14
III-9 Volume Distribution of Randleman Lake III-15
IV-1 Existing Land Use Distribution for the Randleman IV-4
Lake Watershed
IV-2 Future Land Use Distribution for the Randleman IV-7
Lake Watershed
IV-3 Export Coefficients for Soil Types B and C IV-8
IV-4 Phosphorus Loading for Existing Land Use and IV-9
Average Rainfall
IV-5 Nitrogen Loading for Existing Land Use and IV-10
Average Rainfall
IV-6 Phosphorus Loading for Future Land Use and IV-12
Average Rainfall
IV-7 Nitrogen Loading for Future Land Use and IV-13
Average Rainfall
IV-8 Predicted Water Quality for the Existing IV-20
Land Use Case
IV-9 Predicted Water Quality for the Future Land IV-22
Use Case
IV-10 Results for Special Case Years and Existing IV-23
Land Use Conditions
IV-11 Assume That Orthophosphate Equals 50 Percent of IV-25
Total Phosphorus
IV-12 Assume That Non-Algal Turbidity Equals 0.7 IV-26
IV-13 Assume That Non-Algal Turbidity Equals 0.2 IV-27
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Contents (Continued)
Tables
IV-14 Total Phosphorus Concentration of Wastewater IV-28
Treatment Plant Effluent is Reduced to 1,000 ppb
IV-15 Total Phosphorus Concentration of Wastewater IV-29
Treatment Plant Effluent is Reduced to 500 ppb
N-16 The Wastewater Treatment Discharge is Eliminated IV-31
IV-17 Future Land Use Conditions-WW1? Flow is Eliminated IV-32
IV-18 Future Land Use Conditions-WWTP Flow is 20 mgd
with a Total Phosphorus Concentration of 1,000 ppb IV-34
IV-19 Future Land Use Conditions-WWTP Flow is 20 mgd
with a Total Phosphorus Concentration of 500 ppb IV-35
IV-20 Comparison of Lake Water Quality IV-36
V-1 High Point Eastside WWTP Average Effluent V-6
Concentrations
V-2 Concentration of Chemical Contaminants from V-8
Seaboard Chemical Company
V-3 Concentrations of Chemical Contaminants V-9
from the High Point Landfill
V-4 Concentrations of Chemical Contaminants V-10
in Surface Water Inflows to Randleman Lake
V-5 Comparison of Mean Annual Concentrations V-13
of Pollutants with State and Federal Water
Standards
V-6 Range of Mean Annual Concentrations of Pollutants V-14
Calculated by the To,-acs Loading Model With and
Without WWTP Flow
V-7 Comparison of Mean Annual Pollutant Concentration V-16
to Mean Concentration in Oak Hollow and High Point
Lakes
WP07n 190 TC-3
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Contents (Continued)
Figures
Fouowing
Page
I-1 Location Map Proposed Randleman Lake Drainage Basin I-1
I-2 Randleman Lake Watershed I-1
III-1 USGS Gage Locations and Subbasin Delineation III-5
For Yield Analysis
III-2 Schematic of Flows III-15
III-3 Monthly Flow Duration Curves at Ramseur, North Carolina III-17
III-4 Average Annual Flows at Ramseur, North Carolina III-17
III-5 September Average Flows at Ramseur, North Carolina III-17
III-6 Monthly Flow Duration Curves at Carbonton, North Carolina III-17
III-7 Average Annual Flows at Carbonton, North Carolina III-17
III-8 September Average Flows at Carbonton, North Carolina III-17
IV-1 Subbasins of the Randleman Lake Watershed IV-3
IV-2 Watershed Critical Areas for Randleman Lake IV-5
IV-3 Schematic Diagram of the Reservoir Water Quality Model IV-14
IV-4 Distribution of Mean Total Phosphorus Concentrations
for the Existing Land Use Case IV-21
IV-5 Distribution of Mean Chlorophyll a Concentrations for IV-21-
the Existing Land Use Case
IV-6 Distribution of Mean Total Phosphorus Concentrations IV-22
for the Future Land Use Case
IV-7 Distribution of Mean Chlorophyll a Concentrations for IV-22
the Future Land Use Case
WP07112/90 TC-4
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Following
Page
V-1 Locations of Modeled Point Sources of Toxics V-2
V-2 Locations of "Other NPDES Permitted Discharges" V-3
V-3 Distribution of Chromium Concentrations in Randleman Lake V-15
V-4 Distribution of Copper Concentrations in Randleman Lake V-15
V-5 Distribution of Nickel Concentrations in Randleman Lake V-15
V-6 Distribution of Nitrate Concentrations in Randleman Lake V-15
V-7 Distribution of Zinc Concentrations in Randleman Lake V-15
Appendix A
Appendix B
WP07n2/90 TC-5
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I. Introduction
A. Background
The Piedmont Triad Regional Water Authority (PTRWA) has proposed to
construct Randleman Lake, a 3,000-acre water supply reservoir on the Deep River
in Randolph and Guilford counties. The reservoir would be located in the same
drainage basin as Oak Hollow and High Point reservoirs, both of which serve as the
water supply for the City of High Point (Figures I-1 and I-2).
The PTRWA was required to petition the North Carolina Environmental
Management Commission (EMC) for certification before instituting eminent domain
proceedings. The North Carolina Environmental Policy Act requires that environ-
mental documentation be provided to the EMC to assist the EMC in making a deci-
sion on applications for certification. In January 1990, the PTRWA submitted a
Draft Review Document and Environmental Impact Statement (EIS),' which included
updated environmental information reflecting the change in status from a federal to
a local project. The updated EIS also included the original EIS submittal by the U.S.
Army Corps of Engineers as an appendix.
The updated EIS was extensively reviewed by several divisions of the Department
of Environmental Health and Natural Resources. Major written comments were
presented in a letter by Mr. John D. Sutherland of the Division of Water Resources.
This letter reflects the comments of Mr. Trevor Clements of the Division of Envir-
onmental Management.
The following is a summary of Mr. Sutherland's comments. His letter is included
as Appendix A to this report.
The Draft EIS should present enough information to show that the following
requirements are met.
(1) The water in Randleman Lake will be safe to drink.
(2) The reservoir will not be highly eutrophic.
(3) Discharging effluent from the High Point Eastside Wastewater
Treatment Plant to the reservoir is a feasible alternative.
(4) The reservoir will cause no significant adverse impacts on the quantity
or quality of the Deep River water downstream from the project.
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PIEDMONT TRIAD REGIONAL WATER AUTHORITY
RANDLEMAN LAKE
WATERSHED
FIGURE 1-2
The PTRWA desires a safe yield of at least 48 million gallons per day (mgd)
from Randleman Lake. The towns of Jamestown and Randleman; the cities of
Archdale, High Point, and Greensboro; and the County of Randolph will share the
water supplied from the reservoir. This yield was projected by the Corps of
Engineers and reported in the draft EIS.' In 1988, Black & Veatch was retained by
the PTRWA to evaluate the safe yield in the reservoir. Black & Veatch estimated
the safe yield at 50 mgd, assuming a minimum downstream release from the reservoir
of 4.5 mgd. It was also assumed that the City of High Point Wastewater Treatment
Plant (WW'IP) would discharge below the Randleman Dam. Subsequently, the State
Division of Water Resources recommended a three-tiered operating rule that
requires a minimum of 6.5 mgd (10 cfs) in Deep River downstream from the dam.
B. Objective and Scope
The objective of this study was to provide additional information for the PTRWA
Draft EIS to address the comments presented by the Divisions of Water Resources
and Environmental Management.
The scope of work addressed by this study involves the following major areas:
Analvsis of Downstream Flows - Calculate the distribution of streamflows
(flow-duration curves) in the Deep River downstream from Randleman
Lake. Develop flow-duration curves for flows that would occur with and
without the project. Compare these curves to provide an assessment of the
effect that the reservoir would have on the river over a wide range of flow
rates. A re-evaluation of the safe yield for the reservoir considering the
recommended three-tiered operating rule was also included as, part of this
analysis. Major tasks include the following:
• Obtain and evaluate existing streamflow, precipitation, evaporation,
and other relevant data.
• Develop reservoir yield models.
• Develop historical flow records.
• Perform safe yield analyses.
• Develop and evaluate flow duration curves.
I-2
12) Randleman Lake Trophic Level Study - Evaluate the expected trophic level
of the proposed reservoir considering current and future land uses. Major
tasks include the following:
• Obtain and review existing data.
• Develop nonpoint source nutrient loading.
• Develop point source nutrient loading.
• Evaluate trophic status of the reservoir using an empirical
eutrophication model for four different alternatives involving the
High Point Eastside WWTP. These alternatives include:
(1) Existing level of treatment - discharge to reservoir.
(2) Phosphorus removal at the WWTP to an average concentration
of 1 ppm.
(3) Phosphorus removal at the WWTP to an average concentration
of 0.5 ppm.
(4) Diversion of WWTP discharge to a location below Randleman
dam.
(3) Toxic Substances Study - Identify potentially significant sources of toxic
substances, such as metals and synthetic organic compounds, that enter the
lake. Estimate concentrations of these substances at the proposed water
supply intake. Major tasks include the following:
• Obtain and review existing data.
• Identify potentially problem-causing toxic substances.
• Calculate reservoir concentrations of toxic substances and evaluate
the effects of these substances on water quality for two alternatives
involving the Eastside WWTP:
(1) Existing level of treatment - discharge to reservoir
(2) Diversion of WWTP discharge to a location below Randleman
dam.
I-3
C. References
1. "G.S. 162A-7 and 153A-285 Review Document and Environmental Impact
Statement for Randleman Lake, Randolph and Guilford Counties, North
Carolina (Draft)". Prepared by the Piedmont Triad Regional Water Authority,
January 1990.
2. Letter from John D. Sutherland, Division of Water Resources to John Kime,
Piedmont Triad Regional Water Authority, February 9, 1990.
I-4
If. Summary of Findings and Conclusions
A. Downstream Flow and Reservoir Yield Analyses
Findings
1. The yield of Randleman Lake is 54 mgd, and the combined yield of Oak
Hollow and High Point lakes is approximately 18 mgd. The Randleman Lake yield
assumes that 12 mgd of wastewater associated with the yields of Oak Hollow and
High Point lakes is discharged into Randleman Lake by way of the High Point
Eastside W VTP and contributes to the Randleman Lake yield.
2. Up to 26 mgd of the Randleman Lake yield, would return to the Deep River
watershed as wastewater. Of this, up to 20 mgd could be discharged back to the
reservoir, while 6 mgd could be discharged downstream of the reservoir, while 6 mgd
could be discharged downstream of the reservoir to the Deep River. (The 54 mgl
yield does not utilize any of the 20 mgd returned to the reservoir.)
3. Randleman Lake will operate at a volume above 60 percent of its capacity
approximately 90 percent of the time.
Conclusions
L During low flow periods, Randleman Lake will provide higher flows in the
Deep River downstream of the reservoir compared to flows in the river without the
reservoir. This is because the three-tiered minimum release requirement from the
reservoir and wastewater return flow associated with the Randleman Lake yield
supplements flow in the river.
2. On an average annual basis, flows in the Deep River with Randleman Lake
are less than flows in the river without the reservoir. The difference is approximately
equal to the Randleman Lake yield.
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B. Reservoir Trophic Level Evaluation
Findings
1. Average values of mean total phosphorus and mean summer chlorophyll a
in Randleman Lake are predicted to be 141 parts per billion (ppb) and 23.2 ppb
respectively. These predictions include the High Point Eastside WWTP discharging
to the reservoir at an average total phosphorus concentration of 4,000 ppb. The
range of values between years of relatively high flow and low flow is small,
particularly in the most downstream areas of the reservoir. Generally, the highest
concentrations occur during the years of lowest flows. Predicted values of
eutrophication indicators are highest in the most upstream portion of the Deep River
arm of the reservoir (Deep River 1 subbasin), where the WWTP discharge is located,
and lowest in the downstream portion of Muddy Creek (Muddy Creek 2), the
location of the proposed water intake.
2. Mean summer chlorophyll a concentrations are not predicted to exceed
40 ppb, except in the Deep River 1 subbasin. During the growing season, chlorophyll
a is predicted to exceed 40 ppb about 12 percent of the time considering the
reservoir as a whole and about one percent of the time near the intake location.
3. Reducing the concentration of total phosphorus in the WWTP effluent to
500 ppb from its existing level of 4,000 ppb would reduce total phosphorus
concentrations in the Deep River 1 subbasin by 70 percent and chlorophyll a
concentrations by about 15 percent. Reductions in total phosphorus and chlorophyll
a concentrations of about 15 and 10 percent, respectively, are predicted for the
Muddy Creek 2 subbasin.
4. Removing the wastewater effluent would reduce the average reservoir
concentrations of phosphorus and chlorophyll a in Deep River 1 by about 90 percent
and 40 percent respectively. Reductions in the Muddy Creek 2 subbasin would be
about 20 percent and 15 percent, respectively.
5. Mean total phosphorus and mean chlorophyll a concentrations estimated for
the future land use distribution are highly dependent on the amount and quality of
wastewater effluent.
wP07i12,90 II-2
REP168AEB
Conclusions
1. The proposed location for the water intake is in the area of the reservoir that
would have the best water quality.
2. For both existing and future land use conditions, the reservoir is not
predicted to be highly eutrophic.
3. Reducing phosphorus in the WWTP effluent or entirely eliminating the
effluent from the reservoir would have little effect on water quality at the water
intake; however, reductions in phosphorus loadings from the WWTP would
significantly improve the water quality in the most upstream area of the Deep River
arm.
C. Toxic Substances Evaluation
Findings
1. The High Point Eastside wastewater treatment plant effluent, at current dis-
charge concentrations, was estimated to raise the mean annual concentrations of
chromium, copper, nitrates, nickel, and zinc up to twice what the average
concentrations would be without the wastewater discharge to the reservoir. However,
means of all the metals except copper, were less than the North Carolina Department
of Environmental Management (NCDEM) criteria for Class II waters and the
primary Maximum Contaminant Limits for treated drinking water as defined by the
1986 Amendments to the Safe Drinking Water Act (SDWA). The average copper
concentration in the reservoir was somewhat higher than the NCDEM criterion. The
maximum mean annual lead concentration (with WWTP) was equal to the SDWA
criterion.
2. Mean annual concentrations were estimated for the five organic pollutants
present in significant quantities in the groundwater near the Seaboard Chemical site.
These included methylene chloride, 1,1,2,2,-tetrachloroethane, 1,1,1-trichloroethane,
1,1,2-trichloroethane, and toluene. These were modeled because of their widespread
presence at the site and the proximity of the site to the proposed reservoir. Mean
concentrations of all organic pollutants were well below NCDEM and SDWA criteria.
The WWTP was not a significant source of organic pollutants.
3. Calculated pollutant concentrations without the WWTP flow were similar to
the concentrations measured in Oak Hollow Lake and High Point Lake.
wP07n2,90 II-3
REP16MEs
Conclusions
1. Groundwater contamination from the Seaboard Chemical Company and the
High Point landfill sites should not have a significant adverse impact on Randleman
Lake water quality.
2. Discharge of the toxic substances from High Point Eastside WWTP directly
to the reservoir should not create a problem with the proposed Randleman Lake
water treatment plant in meeting the SDWA requirements.
3. Concentrations of organic and inorganic pollutants at the proposed water
intake should be less than the concentrations predicted by the model. This is because
most of the pollutants would enter the reservoir at the upper end of the Deep River
area, and the water intake would be located approximately 10 miles downstream at
lower end of the reservoir. It is expected that significant quantities of organic and
inorganic pollutants would be removed by sedimentation as the water is routed
through the reservoir to the intake location.
WP07112190 II-4
REP168AF-B
Ill. Downstream Flow and Reservoir Yield Analyses
The purpose of the downstream flow analysis is to calculate the distribution of
flows (flow duration curves) in the Deep River, downstream from Randleman Lake,
both with and without the reservoir project. These curves were used in estimating
the changes in flows that would result from the reservoir compared to the existing
condition.
The purpose of the yield analysis is to estimate the safe yield of Randleman Lake
considering historic hydrologic conditions, future water demands by High Point,
wastewater treatment plant return flows, and the three-tiered operating rule
recommended by the State Division of Water Resources to assure minimum
downstream flows. The safe yield of Randleman Lake is defined as withdrawal of
water at a rate which would not deplete the reservoir below an established minimum
elevation for the critical drought period (the most severe historic hydrologic
conditions).
The yield analysis of Randleman Lake was performed using Black & Veatch's
reservoir routing model (BVYIELD) for the water years (October through
September) 1930 through 1988. Downstream releases simulated by the model were
used to develop the flow duration curves. Inputs to the reservoir model included the
following data:
Incremental storage volumes versus depth of water in the lake.
Incremental surface areas versus depth of water in the lake.
• Monthly inflows (streamflow to the lake).
Monthly net lake evaporation (evaporation minus rainfall).
Recommended releases from the reservoir.
• Monthly withdrawals for water supply.
The yield analysis was an iterative process and was performed on a monthly basis
for the period of analysis. First, the Randleman Lake watershed was modeled for the
historic conditions in an attempt to recreate the historic streamflows. This required
collection of historic data and estimation of any missing data such as water use and
wastewater return flows, as well as hydrologic data. The output from this analysis
(monthly streamflows) was compared against measured streamflow data. Since some
of the data used initially to recreate historic conditions were assumed, differences
W?11!29190 III-1
REP16BAEB
between the first analysis results and the measured streamflows were found. To
account for the assumptions used, corrections were applied to the initial data and the
resulting values were used for the Randleman Lake safe yield and flow duration
analysis.
The methods used in determining the data for the safe yield analysis of Randle-
man Lake are described below.
A. Reservoir Characteristics
In addition to the proposed Randleman Lake, the system also includes two exis-
ting reservoirs - Oak Hollow Lake and High Point Lake. The safe yield analysis of
Randleman Lake necessitated the analysis of the two existing reservoirs because the
yield available from Randleman Lake is dependent on the yields of the two existing
reservoirs.
1. Randleman Lake
The proposed Randleman Lake would have a total drainage area of 171 square
miles (sq mi), a normal water surface elevation of 682 feet above mean sea level
(feet msl) and a minimum water surface elevation of 635 feet msl. At the normal
water surface elevation, the reservoir would have a surface area of 3,230 acres
(5.1 sq mi) and a storage volume of 18.3 billion gallons. Table III-1 presents the full
range of elevation, storage volume, and surface area values used for the yield
analysis.
The data in Table III-1 take into account that during the 100 year design life of
the reservoir, a certain portion of the storage volume would be lost to sediment depo-
sits from inflow to the lake. Since no observed values for erosion or sedimentation
were available for the watershed, the amount of erosion, and a corresponding sedi-
ment loading to Randleman Lake, were estimated based on measured data for other
reservoirs. Fourteen reservoirs were chosen to provide data for estimating erosion
and sedimentation to Randleman Lake.' These reservoirs were chosen because of
their proximity and similarity of watershed size to the Randleman Lake watershed.
Approximately 163 years of erosion data for the 14 reservoirs and their associated
watersheds were used. An annual average erosion rate was determined and weighted
according to the period of record for the reservoirs. A weighted annual average for
all reservoirs was estimated to be approximately 3.86 acre-feet of sediment per square
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Table III-1
Reservoir Characteristics
Reservoir
Randleman Lake
Oak Hollow Lake
High Point Lake
Water Surface
Elevation,
ft-msl
630
635
640
645
650
655
660
665
670
675
680
682
770
775
780
785
790
795
800
803
722.5
725
730
735
740
745
750
755
757
Storage,
billion gallons
0.0
0.4
0.9
1.6
2.5
3.7
5.2
7.2
9.7
12.8
16.5
18.3
0.01
0.1
0.3
0.6
1.1
1.8
2.6
3.3
0.0
0.02
0.05
0.1
0.2
0.4
0.6
1.0
1.2
Surface Area,
acres
200
300
430
550
690
910
1200
1520
1890
2340
2850
3230
50
120
190
270
360
470
580
700
0
20
60
100
140
180
220
260
wP11R9/90 III-3
REP168AEB
mile of watershed per year.' This value was then converted to transported and
trapped sediment values using Soil Conservation Service (SCS) methods.2 These
methods consider the watershed size, average flow to the reservoir, and reservoir
storage volume. The resulting sediment loading to Randleman Lake of
0.461 acre-feet per square mile per year, or 7,880 acre-feet of accumulation in 100
years compares well with an earlier estimate of 8,000 acre-feet made by the U.S.
Army Corps of Engineers.3
2. Oak Hollow Lake
Oak Hollow Lake, completed in 1971, has a drainage area of 31.2 square miles
and a normal water surface elevation of 803 feet msl. At the normal water level, the
lake has a storage volume of 3.3 billion gallons and a surface area of approximately
700 acres. Table III-1 indicates the full range of elevation, storage volume, and
surface area values used for the analysis of Oak Hollow Lake. For purposes of
analysis, the minimum water level at which there would be no detrimental effects to
the lake was set at elevation 786 feet above mean sea level.
3. High Point Lake
High Point Lake was completed in 1928. It has a total drainage area of 61.4
square miles, a surface area of 275 acres, and storage volume of 1.2 billion gallons
at a normal water surface elevation of 757 feet msl. Table III-1 indicates the full
range of elevation, storage volume, and surface area values used for the analysis of
High Point Lake. For purposes of the analysis, the minimum water level at which
there would be no detrimental effects to the lake was set at elevation 742 feet msl.
B. Reservoir Inflows
To analyze inflows to Randleman Lake, to identify the critical drought period for
the lake, and to compute its safe yield, both Oak Hollow and High Point lakes were
evaluated for the period of analysis (water years 1930 to 1988). This analysis
required information on inflows to Oak Hollow and High Point lakes, as well as to
Randleman Lake. To provide flexibility in the analysis of existing and future
conditions, the watershed was divided into five subbasins, and "virgin flows" were
calculated for each subbasin. "Virgin flows" are defined as the flows that would have
occurred if man had not developed and modified the natural setting of the watershed,
i.e., no withdrawals for water supply and no return flows from the wastewater treat-
WP11(29/90 III-4
REP16BAEB
ment plant. The calculation of virgin flows required historic information on precip-
itation, lake evaporation, streamflows, water use by the City of High Point, and
wastewater return flows.
t. Subbasin Delineation
For calculation of the virgin flows, the Randleman Lake watershed was divided
into five subbasins. The subbasins were chosen based on the locations of the two
eadsting lakes and on the location of U.S. Geological Survey (USGS) streamflow
gaging stations.4 The subbasin delineation and locations of streamflow gaging stations
are indicated on Figure III-I. Table III-2 presents information on the USGS
streamflow gaging stations and Table III-3 lists the information on the subbasins used
for the analysis.
Table III-2
Available USGS Streamflow Gaging Stations
Gage Identification USGS Gaging Drainage Area, Period of Record
on Figure III-1 Number square miles
1 02099000 14.8 1929 -1989
2 02098500 32.1 1924 -1958
3 02099500 125 1929 -1989
4 02100500 349 1923 -1989
2. Precipitation and Lake Evaporation
Precipitation and lake evaporation combine to produce net lake evaporation,
which is equal to the lake evaporation minus the precipitation. Monthly precipitation
data for Randleman, North Carolina, were available for the period of analysis.5 It
was assumed that the rainfall which occurred at the precipitation gage at Randleman
would be uniform across Randleman Lake.
wPl 1/29/90 III-5
REMMEB
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SCALE IS MILES
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SUSBASIN IDENTIFICATION
SUBBASIN BOUNDARY
U36S CAGE LOCATION
AND IDENTIFICATION
P*OP fD
RAMDLIMA1
ate` LAKE
k 41111
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
USGS GAGE LOCATIONS AND
SUBBASIN DELINEATION FOR
YIELD ANALYSIS
FIGURE M-1
Table III-3
Subbasin Characteristics
Subbasin Designation I Description
A Area tributary to Gage 1
B Area tributary to Oak Hollow
Lake
C Incremental area tributary to
High Point Lake (not including
subbasins A and B)
D Incremental area tributary to
High Point Lake (subbasins A
and C)
E Incremental area between High
Point Lake and Gage 3
F Incremental area between Gage 3
and the Randleman dam site
G Incremental area between
Randleman dam site and Gage 4
Area
(sq mi)
14.8
31.2
15.4
30.2
63.6
46.0
178.0
Evaporation data is normally presented as "pan evaporation" rather than lake
evaporation. Pan evaporation is determined based on the amount of evaporation
that occurs from a "pan" of specified dimensions. As measured, pan evaporation is
a percentage of the lake evaporation, depending on the geographic location of the
site. This percentage, known as a pan coefficient, is used to convert pan evaporation
to open water (lake) evaporation values. Monthly pan evaporation data were not
available for the entire period of analysis. Monthly values were available for part of
the period of analysis for a station at Chapel Hill, North Carohna.5 These data were
used as a basis for developing the missing pan evaporation data. The pan
evaporation data for Chapel Hill were plotted versus monthly temperature, also
WPi1R9/90 III-6
REP]68AEB
recorded at Chapel Hill,5 on semi-log paper and a 'best fit" line was drawn through
the data. The line was skewed to best fit the higher temperatures to assure that the
evaporation data calculated would be applicable for the critical drought period when
temperatures are typically higher. Based on the data, the equation used for relating
pan evaporation and temperature was determined to be:
PAN EVAP = 10.01161TEMP - 0.0177)
where PAN EVAP is the monthly pan evaporation in inches, and TEMP is the
average monthly temperature in degrees Fahrenheit. The Chapel Hill pan
evaporation data were converted to pan evaporation values at Randleman by
reducing the Chapel Hill values by 2 percent. This was done to compensate for the
difference in geographical location of the two cities. Finally, to convert the monthly
pan evaporation to the required monthly lake evaporation, the pan evaporation data
was multiplied by a pan coefficient of 0.73.
Before calculating the net lake evaporation, the monthly lake evaporation values
were lagged by one month to account for the hysteresis (time lag) of lake evaporation
due to the thermal storage of the lake. The monthly net lake evaporation values
were then calculated as lake evaporation minus precipitation.
3. High Point Water Use
Potable water is supplied to the City of High Point from two water treatment
plants. The Ward Plant, constructed in 1982, is the main treatment plant. The
second plant, the Kearns Plant, has been in operation since the 1920s and serves to
supplement the Ward Plant supply during periods of high demand.
Historic water use data for High Point were obtained from available city records.
Some of the data pertained to raw water flows (before treatment) while other
information represented finished water flows (after treatment). Where comparison
of raw water versus finished water flows was possible, the raw water flows were
approximately 18 percent higher than the finished water flows. The difference was
attributed to water use at the treatment plants, differences in calibration of the
meters used to measure the flows, and losses within the distribution system. To
assure an adequate analysis, all finished water flow data was increased by 18 percent
to convert the values to the more conservative raw water flows.
wP11/29/90 III-7
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Monthly water use data were available for calendar years 1985 through 1989,
while yearly data were available for calendar years 1975 through 1984. For the
period prior to 1975, data were available for calendar years 1930, 1940, 1950, 1960,
and 1970. Linear interpolation was used to estimate the yearly flows between the ten
year data intervals. The yearly water use totals for the calendar years 1930 through
1984 were distributed monthly using 'the five years of monthly data (1985 through
1989) as a basis. Assumed average daily use ranged from a minimum of 2.4 mgd to
a maximum of 13.2 mgd.
A monthly "demand factor" was computed for each month of the five years of
data by dividing the monthly water use by the total water use for the year. The five
January demand factors were averaged, the five February demand factors were
averaged, and so on, for March through December, to provide average monthly
demand factors for the entire water year. These demand factors were used to
distribute the yearly flow data on a monthly basis for the years 1929 through 1984.
It was assumed that for the historic conditions, the monthly demand factors were
cyclic, i.e., the October demand factor would be used for each October for the period
of analysis, the November demand factor would be used for each November for the
period of analysis, and so on for December through September of each water year.
Values for the monthly average demand factors are shown in Table III-4.
Table III-4
Monthly Water Use Demand Factors
(Multiple of average annual demand divided by 12)
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
1.04 0.95 0.92 0.95 0.86 0.96 0.97 1.03 1.05 1.10 1.15 1.04
4. High Point Wastewater Return Flows
The City of High Point operates two wastewater treatment plants, the Eastside
WWTP and the Westside WWTP. The Westside WWTP does not discharge within
the Randleman Lake watershed and therefore this flow was not considered in the
analysis. Discharge data for the Eastside WWTP, which does discharge to the
Randleman Lake watershed, were available for calendar years 1962 through 1989.
The average ratio of monthly raw water flow to monthly wastewater flows computed
wP11/29190 11I-8
REP16BAEB
for the years 1962 through 1989 was approximately 0.68. This ratio was applied to
the previously calculated historic monthly water use for 1930 through 1961. The
resulting values indicated wastewater plant return flows for the period of analysis.
Flows from the Eastside WWTP ranged from 1.6 mgd to 11.4 mgd.
5. Virgin Flows
The calculation of virgin flows was an iterative process and was based on a
comparison of the reservoir routing model output to the streamflow data at USGS
streamflow gaging stations. In particular, measured streamflows at gage 3 were
compared with flows generated by BVYIELD (Figure III-1). Initial inflows to the
reservoirs were based on streamflow data at gage 1 (subbasin A). This gage was
chosen since there are no reservoirs upstream that would alter the streamflow. The
initial incremental flows for subbasins B, D, and E, were calculated based on the
period of record for the particular USGS streamflow gaging stations and the ratio of
subbasin areas, minus the area of the reservoirs, to Subbasin A. These incremental
flows are the result of precipitation that falls on the subbasin.5 It was necessary to
subtract the surface area of the lakes since the precipitation that falls on each lake
was previously accounted for in the net lake evaporation calculations. Table III-5
presents the flow calculations for each subbasin.
Table III-5
Initial Flow Calculations Equations
Il Subbasin I Period of Analysis I II
l Designations (Water Years) 1 Streamflow Calculation Equation
B 1930 to 1958 [(31.2 - 1.1)/32.1] x (gage 2 flows)
1959 to 1988 [(31.2 - 1.1)/14.8]x (gage 1 flows)
D 1930 to 1988 [(30.2 - 0.43)/14.8] x (gage 1 flows)
E 1930 to 1988 [63.6/14.8] x (gage 1 flows)
F 1930 to 1988 [(46.0-5.1)/224]) x (gage 4 flows - gage 3
flows)
The total period of analysis, water years 1930 through 1988, was divided into two
groups for determining the virgin flows: 1930 through 1970, and 1971 through 1988.
This was done to account for the completion of Oak Hollow Lake in 1971. Prior to
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REP168AEB
1971, the inflow to High Point Lake consisted of the sum of flows from Areas A, B,
and C. These flows, in addition to the estimated net lake evaporation and monthly
water supply withdrawals from High Point Lake, were input to the BVYIELD model
for High Point Lake. This data set was used as the best estimate for replicating
historic conditions. The output from BVYIELD consisted of monthly "spills" (flows
discharged from the reservoir spillway). These spills were added to the incremental
flows computed for subbasin E and the estimated wastewater return flows from the
Eastside WW TP, and then compared to the streamflow data at gage 3.
A similar approach was used for the determination of virgin flows for water years
1971 to 1988. However, since Oak Hollow Lake was in operation after 1971, it was
analyzed first. The incremental flows for subbasin B were entered into BVYIELD
with the net lake evaporation data. There have been no water supply withdrawals
from Oak Hollow Lake, so no withdrawals were necessary for input to BVYIELD.
The Oak Hollow spills computed by BVYIELD were combined with the flows
produced from subbasin D for input to the High Point Lake model. High Point Lake
was analyzed using these inflows, water supply withdrawals, and net lake evaporation
for the historic conditions of 1971 through 1988. The High Point spills were combined
with the flows computed for subbasin E and the estimated wastewater return flows,
and compared to the streamflow data for gage 3 for water years 1971 through 1988.
The flows computed with BVYIELD differed from those measured at gage 3.
The differences were the result of (1) assuming uniform unit runoff yield throughout
the watershed, (2) the assumptions used to estimate historic water supply withdrawals
from High Point Lake, (3) the assumptions used to estimate the wastewater return
flows from the Eastside WWTP, and (4) the. assumption that the amount of virgin
flows for the ungaged areas was proportional to the flows for gage 1. These differ-
ences between the calculated and the recorded monthly flows at gage 3 were
accounted for by distributing them among the virgin flows initially calculated for the
ungaged subbasins in the Randleman Lake watershed (subbasins B, C, and E). The
monthly flow differences were distributed on the basis of the ratio of the ungaged
subbasin areas to the total ungaged area. The basis of distribution of the differences
is shown in Table III-6.
The distribution of the differences was performed for two different periods: 1930
through 1958, and 1959 through 1988. This was necessary due to the period of
wP11R9/90 III-10
REP16BAEB
record for gage 2 (Table III-1), downstream from subbasin B. Prior to 1959,
subbasin B was a gaged area, and therefore no correction was applied to the subbasin
for that period. The gage was removed in 1959, and from that point on subbasin B
was ungaged.
Table III-6
Distribution of Flow Differences
Subbasin
Water Years Area Percentage of Correction Applied
Designations ,
sq mi
1930- 1958 C 15.4 (15.4/79.0) = 19.5%
E 63.6 (3.6/79.0) = 80.5%
Total 79.0 Total = 100.0%
1959 - 1988 B 31.2 (31.2/112.0) = 28.3%
C 15.4 (15.4/112.0) = 14.0%
E 63.6 (63.6/112.0) = 57.7%
Total 112.2 100.0%
After these corrections were applied to the calculated flows from the ungaged
subbasins, the resulting runoff hydrographs represent the virgin flows for subbasins
A, B, C, and E. These flows, combined with the flows from subbasin F, represent the
virgin flows for the Randleman Lake watershed.
C. Randleman Yield
The foregoing virgin flow analysis was completed to obtain the best possible
estimates of runoff for each of the subwatersheds for analyzing the yield of
Randleman Lake. The input to the BVYIELD model for the yield evaluation consis-
ted of the virgin flows from the subbasins modified as necessary to reflect future
conditions within the watershed; that is, conditions upstream from Randleman Lake
(primarily the operation of Oak Hollow and High Point lakes), and recommended
releases from Randleman Lake.
WP11/29/90 III-11 .
REP168AEB
1. Upstream Conditions
The City of High Point obtains its raw water from High Point Lake. With the
completion of a pump station at Oak Hollow Lake, the City may also withdraw water
directly from Oak Hollow Lake. Therefore, the future yield of Randleman Lake was
computed assuming that the maximum yield from both Oak Hollow and High Point
lakes was utilized by High Point. The BVYIELD model determined that the
combined yield for both reservoirs is approximately 18 mgd. Maximizing the with-
drawals from these reservoirs will reduce the flows discharged from High Point Lake
and will therefore provide a conservative estimate of the yield of Randleman Lake.
2. Recommended Downstream Flows
To assure adequate low flows in Deep River downstream from Randleman Lake,
a three-tiered operational rule recommended by the State was utilized. This rule
makes releases a function of downstream flows and the volume of water remaining
in the reservoir. When the reservoir is less than 30 percent full, a minimum of 10 cfs
downstream flow is required; when it is between 30 and 60 percent full, a minimum
of 20 cfs downstream flow is required; and when it is above 60 percent full, a
minimum downstream flow of 30 cfs is required. Downstream flows are taken as the
sum of any bypassed wastewater flows and/or reservoir releases.
3. Wastewater Treatment Plant Flows
In computing the yield of Randleman Lake, it was assumed that the Eastside
WWTP would discharge a flow of 12 mgd (18 cfs). This is the wastewater return flow
associated with the previously discussed 18 mgd yield from Oak Hollow and High
Point lakes. This wastewater flow was computed by multiplying 18 mgd by 0.68 which
is the historical ratio of wastewater flows to the Eastside WWTP to the raw water
usage by the City. This ratio is discussed in Section III-B-4.
Although it is possible that wastewater return flow associated with the
Randleman Lake yield may be discharged to the lake through this WWTP or another
plant, it was assumed that the return flow from this "new" yield would not be included
in the yield computation for Randleman Lake.
wP11/29/90 III-12
REP168AEB
4. Yield
The BVYIELD model computed a yield for Randleman Lake of 54 mgd. The
critical period was April 1966 through November 1967 when the reservoir was drawn
down to a volume of 1100 acre-feet during November 1967.
D. Flow Duration Analysis
The purpose of the flow duration analyses is to determine the effect that
Randleman Lake would have on flows at locations on the Deep River, downstream
from the reservoir. These downstream flows were based on the required minimum
reservoir releases, spills from the reservoir, wastewater treatment plant return flows
resulting from communities downstream from the lake using portions of the potential
Randleman yield, and incremental runoff from the watershed downstream from
Randleman Lake.
The required minimum releases were a result of the three tiered release rate
discussed in section III-C-2, while the spills from the reservoir occurred when the
reservoir's storage potential was full (i.e. the reservoir was overflowing). To quantify
the wastewater treatment plant return flows from the downstream users, it was
necessary to determine the amounts of Randleman Lake yield that would be
allocated to the various users who would share the water from the project. The
PTWRA agreement allocated 48 mgd, as shown in Table III-7.
For purposes of developing conservative flow duration curves, the North Carolina
Department of Water Resources has requested that the 54 mgd yield be evaluated.
WP11/30/90 III-13
REP168AEB
Table III-7
ALLOCATION OF RANDLEMAN
LAKE YIELD
JURISDICTION SHARE,
mgd PERCENT
Greensboro 28.5 59.4
High Point 10.1 21.0
Archdale 1.2 2.5
Jamestown 1.2 2.5
Randleman 1.0 2.1
Randolph County 6.0 12.5
TOTAL 48.0 100.0
Table III-8 provides a water balance of the yields and wastewater return flows
associated with Randleman Lake and includes the allocation of 72 mgd - the 54 mgd
Randleman Lake yield and the 18 mgd yield from Oak Hollow and High Point lakes.
Table III-8 also includes a wastewater return flow of 25.9 mgd that would return to
either Randleman Lake or the Deep River below the reservoir. Of this return flow,
12 mgd results from the Oak Hollow and High Point lake yields and the remaining
13.9 mgd is return flow associated with the Randleman Lake yield. The wastewater
was assumed to be 75 percent of the yield. For High Point, it was assumed that 70
percent of the wastewater would remain in the Deep River watershed and 30 percent
would be discharged from the High Point Westside WWTP, out of the watershed.
To complete the balance, Table 111-8 shows that 46.1 mgd is lost from the Deep
River watershed. This includes 32.1 mgd of yield that would be pumped out of the
watershed to Greensboro, 2.6 mgd of wastewater return flow at the High Point
Westside WWTP lost from the watershed, and the remainder as consumptive losses
(25 percent of the Randleman Lake yield plus 6 mgd associated with the Oak Hollow
and High Point lakes yields). Actually, not all of the 6 mgd loss is consumptive --
part of this flow would be discharged at the Westside WWTP. For purposes of
WP11/30ft III-14
REP168AEB
Table III-8
RANDL.EMAN LAKE
WATER BALANCE
mgd
Yk kts from Randleman Lake
Greensboro 32.1
Haigh Point 11.3
Archdale 1.4
Jamestown 1.4
Randleman 1.1
Randolph County 6.7
Total 54.0
Yields from Oak Hollow and High Point Lakes 18.0
vVhahw der Retum Row to Randle min Lake
and Deep River'
Greensboro 0
High Point-Randleman Yield 5.9
High Point-Oak Hollow and High Point
Reservoir Yields 12.0
Archdale 1.1
Jamestown 1.1
Randleman 0.8
Randolph County 5.0
Total 25.9
Losses from Deep River WManiihed
Greensboro Consumptive 32.1
High Point-Randleman Yield 2.8
High Point Reservoir Yield* 6.0
Archdale 0.3
Jamestown 0.3
Randleman 0.3
Randolph Cwnty 1.7
High Point Westside WWTP from Randleman 2.6
Lake Yield
Total 46.1
Summary
Yields
Randleman 51.0
Oak Hollow and High Point 18.0
Total 72.0
Wastewater Return 25.9
Losses from Deep River Watershed 46.1
Total 72.0
'Wastewater from Randleman and Randolph County assumed to be discharged below Randleman Lake. All other
wastewater flow will be discharged into reservoir.
*A portion of this flow returns to the High Point Westside WWTP.
performing the flow duration analyses, it was assumed that the wastewater return
flows shown in Table III-8 from High Point, Archdale, and Jamestown would be
discharged to Randleman Lake, while the wastewater return flow associated with the
City of Randleman and of Randolph County would be discharged to the Deep River
below the reservoir.
After the water balance was established, the yield analysis was performed
assuming a total wastewater flow into the lake of approximately 20 mgd. This
includes the 12 mgd wastewater flow from the previous run plus 8 mgd of wastewater
associated with the Randleman yield. However, for this run, it was assumed that
none of the 8 mgd would be used to increase the yield beyond 54 mgd. As a result,
the model showed that during the critical drought period of 1967, the minimum
reservoir volume increased to approximately 11,000 acre-feet versus the 1,100 acre-
feet volume established as the minimum volume for the safe yield analysis. This
additional volume is primarily the wastewater stored during the drought period.
Table III-9 presents the percent of time the reservoir is at the reservoir volumes
stipulated for the three-tiered minimum release rates. For example, the table shows
that 91.7 percent of the time, the reservoir would be operating at greater than
60 percent of its storage capacity. Figure III-2 is a schematic of the reservoir system
that was modeled.
Table III-9
VOLUME DISTRIBUTION OF RANDLEMAN LAKE
Percent of
Reservoir Volume Percent of Time
<30 0.3
>30 - 60 8.0
>60 - 100 91.7
Flow duration analyses were performed for the Deep River at the Ramseur
USGS gaging station (349 square mile tributary drainage area) and at the Carbonton
Dam site (1,026 square mile tributary drainage area). Relative locations are shown
on Figure III-2. The purpose of the analyses was to compute the percent of time
that a given flow would be exceeded in the Deep River at the two locations for
various conditions. Three analyses were performed for two conditions at each site.
The three analyses included average monthly, average annual, and average
WP11/30/90 III-15
REP16BAEB
September flow durations. The two conditions included the base condition - flows
in Deep River without Randleman Lake, and Deep River flows including the effects
of the reservoir. Flows considered in the Deep River for the base condition included:
• Spills from High Point Lake.
• Wastewater treatment plant return flows resulting from the yields of Oak
Hollow and High Point lakes (12 mgd).
• Runoff from the tributary watershed downstream from the High Point Lake,
to the points of interest.
It was assumed that no additional yield would be available without the lake.
Therefore, no additional wastewater treatment plant return flows were included. The
estimation of flows in the Deep River when the effect of Randleman Lake was
considered included:
• Minimum required releases from Randleman Lake (from BVYIELD model).
• Spills from Randleman Lake (from BVYIELD model).
• Wastewater return flows resulting from the potential yield from Randleman
Lake (5.8 mgd) [Table III-8].
• Incremented runoff from the tributary watersheds downstream from
Randleman Lake, to Ramseur or Carbonton Dam.
The above wastewater flow of 5.8 mgd, as well as all other wastewater flows used
in this analysis, are annual averages. To obtain the monthly average wastewater flows
used by BVYIELD model, the annual average values were multiplied by monthly
adjustment factors, which were developed from several years of operating data from
the High Point Eastside WWTP.
No stream-flow information was available at the Carbonton Dam site to estimate
the runoff from the tributary watershed. Therefore, the flows produced by the
incremental drainage area between Randleman Lake and the Carbonton Dam site
of 855 square miles (1,026 square miles minus 171 square miles) were generated.
These flows were calculated as 855 square miles multiplied by the unit runoff (per
square mile) for the flows generated between the 349 square mile stream-flow gage
(U.S.G.S. Gage 02100500) and the 125 square mile stream-flow gage (U.S.G.S. Gage
02099500).
WP11r30/90 III-16
REP 168A -B
TRIBUTARY RUNOFF
OAK HOLLOW ?----? Oak Hollow
Yield
Oak Hollow Spills and Tributary Runoff
HIGH POINT High Point
Yield
High Point Spills and Tributary Runoff
Wastewater Return RANDLEMAN Randleman Yield to Greensboro
(Out of Watershed)
Flows From LAKE
Hi ghpoint Archdale Randleman Yield to Highpoint,
and Jamestown Archdale, Jamestown, Randleman,
and Randolph County
Wastewater Randleman Spills and Minimum Downstream Releases
Return Flows
From Randleman Tributary Runoff
and Randolph
County Ramseur
Tributary Runoff
LEGEND
¦ INDICATES LOCATIONS OF Carbonton Dam
FLOW DURATION ANALYSES
SCHEMATIC OF FLOWS I Figure
111- 2
IV. Reservoir Trophic Level Evaluation
One of the goals of this study was to estimate the trophic level of the proposed
Randleman Lake based on estimated current and future nutrient inputs. A reservoir
eutrophication model developed by W. W. Walker was used to calculate expected
nutrient levels in the reservoir. The model relies on loading estimates of point and
nonpoint sources of nutrients to calculate total phosphorus and algae (chlorophyll a)
concentrations within the pool. The nonpoint source estimates were based on the
distribution of land use, nutrient export coefficients, and runoff data. Point source
estimates were based on monitoring data and permit requirements. This work was
completed using existing information.
A. Review of Existing Information
Nonpoint sources are difficult to measure because of their diffuse and
intermittent nature. Several studies have been conducted to measure nonpoint
source loadings of nutrients and other constituents. These studies were conducted
primarily to determine export coefficients which describe the amount of a nutrient
or other constituent that would be washed off the land in stormwater runoff. Export
coefficients are typically expressed in units of pounds per acre per year (lb/acre-yr).
Beaulac and Reckhowl conducted a literature review of published nutrient
export coefficients. They compiled and analyzed data from studies where acceptable
methods and sampling design were used. The data showed that export coefficients
depend on soil type, land use, precipitation and runoff. They are also dependent on
slope, orientation and other watershed characteristics; however, data on these latter
characteristics were generally not presented in the studies analyzed.
Beaulac and Reckhow performed a statistical analysis of export coefficients for
forest, pasture, feedlot, row and nonrow crops, mixed agricultural, and urban land
uses. They found that, except for forest lands, there is a large variability in reported
values. Coefficients for agricultural lands are very sensitive to soil types and
management practices. For example, silt loams, the predominant soil type in the
Randleman Lake watershed, have a high capacity for nutrient adsorption and are also
highly erodible, which results in a relatively high export coefficient. Export
coefficients for urban areas are highly dependent on the amount of impervious
surface. Urbanization changes the natural storm runoff hydrograph, resulting in a
higher peak and shorter duration with increased storm runoff and lower baseflow.
IV-1
More recent estimations of export coefficients have been based primarily on data
from the Chesapeake Bay Program' and the Nationwide Urban Runoff Program
(NURP).3 Hartigan, et al.,4 derived nonpoint source (NPS) loading factors by using
the Chesapeake Bay data and calibrating a NPS continuous simulation models for
eleven small watersheds, each consisting of a single land use. Export coefficients for
six land uses - forest, pasture, single family residential, commercial, low tillage
cropland, and high tillage cropland - were developed for an average rainfall year and
a wet year. Soils and rainfall in the study area are similar to those in the Randleman
Lake watershed.
The EPA NURP data3 were collected in 75 urban test watersheds located in 15
metropolitan areas across the country. A statistical analysis of the data showed that
event mean concentrations of nutrients associated with runoff from different urban
land uses were not significantly different. The nutrient loading differences were
positively related to the volume of runoff. Runoff is positively related to im-
perviousness; therefore, loading factors were also positively related to imperviousness.
Other studies 6,7 conducted for Piedmont basins in northern Virginia also show a
positive relationship between nutrient loading and imperviousness of urban areas.
In addition, the export coefficients derived in those studies are very similar to the
NURP values.
The watershed for the proposed Randleman Lake covers approximately 171
square miles and contains two reservoirs (Figure I-2). Terrain in the watershed is flat
to gently rolling. The upper part of the watershed, which contains the cities of High
Point, Jamestown, and Greensboro, is relatively urbanized while the lower portion in
Randolph County is primarily rural and agricultural.
The upper part of the watershed comprises two subbasins for the existing
reservoirs, Oak Hollow Lake and High Point Lake, with drainage areas of 32 and 30
square miles respectively. A watershed management plan was developed for these
two subbasins by Camp, Dresser & McKee.e This plan lists the types of land use in
the upper watershed and contains acreage estimates for each type of land use in the
two subbasins. The plan also contains estimates of nonpoint source loadings and
results of water quality modeling. Export coefficients for urban lands were derived
from studies conducted in the Piedmont basins of northern Virginia3 9 and adjusted
for local rainfall conditions. Export coefficients for rural and agricultural lands were
based primarily on Chesapeake Bay Program data.2,4
IV-2
s•
For this study, the watershed has been divided into eight subbasins as shown on
Figure IV-1. The watershed below High Point Lake was divided into six subbasins
to better quantify inputs to specific portions of the reservoir and to facilitate the ..
modeling. In this way, the spatial distribution of phosphorus in the reservoir could
be better described.
let
B. Nonpoint Source Loadings
Nonpoint source loadings of total phosphorus were estimated for the Randleman
Lake watershed by first delineating the land use types and quantifying the area of
each type in each subbasin, and then applying export coefficients to estimate
stormwater loadings. Baseflow and stormwater contributions were added to estimate
total loadings of phosphorus to each subbasin. .
Many of the tasks discussed below were also performed in developing the
Watershed Management Study8 for the Oak Hollow Lake and High Point Lake
watersheds. Whenever possible, the methods used in the Watershed Management
Study were also used in the current Randleman Lake study. It is hoped that by en-
hancing the compatibility of the two studies, the usefulness of both would be
increased.
1. Land Use Distribution
Land use in the watershed consists of forest, open area, pasture, cropland,
residential, commercial, industrial, and water supply uses. These have been further
subdivided into a total of 14 land use types. The distribution of existing land uses in
each of the eight subbasins is presented in Table IV-1. The acre values for the Oak
Hollow and High Point subbasins are the same as those presented in the Watershed
Management Study.e The same land use types were also applied for the other six
subbasins.
The information in the table came from a variety of sources. Data for urban
areas were developed from land use maps,10,11.12 USGS topographic maps, and
aerial photographs. Data for rural and agricultural areas were developed from Soil
Conservation Service maps and reports, 13,14 USGS topographic maps, and aerial
photographs. In residential areas the density of housing units was determined from
local land use plans, major subdivision plans, topographic maps, and aerial photo-
graphs. The percent impervious surface values for various land use types are the
same as those used in the Watershed Management Studye and were based on local
ordinances, subdivision plans, and aerial photographs.
IV-3
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IV-4
a
The data used are considered to be the most up-to-date information available.
However, for many areas the most recent data are several years old. In addition,
information from several sources was available for some areas, e.g., near High Point,
while very little was available for other areas, e.g., Randolph County.
Both Guilford and Randolph Counties have adopted watershed protection
ordinances which would restrict development near the reservoir. The watershed
critical area boundary for Randleman Lake is shown on Figure N-2. In Randolph
County the watershed critical area boundary is located one-half mile from the high
water mark of a public water supply. Within this area, no industrial uses are
permitted and the minimum lot size for residential use is 80,000 sq ft (2 acres).
Commercial and institutional uses are limited to 3,000 sq ft of floor space and not
more than 6 percent impervious surface area for the site. In Guilford County, the
watershed critical areas are divided into the four tiers defined below.
' Tier 1: Lands within 200 feet of the normal pool elevation; around Randleman
Lake these will be purchased by the PTRWA and no development will
be allowed.
Tier 2: Lands between 200 feet and 750 feet from the normal pool elevation;
minimum lot size is 5 acres.
Tier 3: Lands between 750 feet and 3,000 feet from the normal pool elevation;
minimum lot size.:is.3 acres; in some areas the tier 3 boundary is the
watershed criti fgr6a boundary.
Tier 4: Lands between 3,000 feet from the normal pool elevation and the
watershed critical area boundary; minimum lot size is one acre;
development is prohibited on lands with slopes greater than 15 percent
adjacent to streams.
The Watershed Management Plana for the upper watershed looked at five
possible cases of future development of the watershed. One of these (Alterna-
tive III), representing a worst case for nutrient loading, is used as the future case for
the Randleman Lake watershed. In this case, it is assumed that all unincorporated
areas of Guilford County are annexed by the cities of High Point and Greensboro,
and that 90 percent of this area is developed into urban uses. This includes
substantial commercial and industrial development. In Randolph County, much of
the reservoir watershed is included in the Watershed Critical Area which places
N-5
CERIUM LLE
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PIEDMONT TRIAD REGIONAL WATER AUTHORITY
WATERSHED CRITICAL AREAS FOR
RANDLEMAN LAKE
FIGURE =-2

restrictions on development. For the future case, it is assumed 50 percent of the
watershed area in Randolph County was developed into urban uses. The distribution
of land use for this case of future development is presented in Table IV-2.
2. Soil Types
Soils in the Randleman Lake watershed are primarily a sandy clay loam type of
the Georgeville and Mecklenburg variety.15 They fit into two hydrologic soils
groups, B and C, defined by the Soil Conservation Service 16 as:
B: Moderate infiltration rate when thoroughly wetted, moderately well to well-
drained soils, moderately fine to coarse texture.
C: Slow infiltration when thoroughly wetted, drainage is impeded by clay layers,
fine to moderately fine texture.
Soils in the watershed are approximately 30 percent type B and 70 percent type C.8.14
3. Export Coefficients
The export coefficients developed for the upper watershed8 and for a typical
rainfall year are shown in Table IV-3. Export coefficients are listed for each land use
and soil type. These were derived primarily from published export coefficients
developed for Piedmont basins in northern Virginia.4 A relationship between percent
impervious surface and export coefficient was used to establish export coefficients for
the various densities of residential land uses. To account for the slightly higher
rainfall conditions in the upper Deep River basin, the published data were converted
to event mean concentrations and multiplied by local surface runoff values.8 These
export coefficients were used to calculate the stormwater loading of total phosphorus
(TP) and total nitrogen (TN) into each of the eight subbasins of the reservoir (Tables
IV-4 and IV-5).
The export coefficients were derived from studies conducted in small, single land
use watersheds. In these smaller watersheds runoff tends to enter the waterbody
directly. It is thought that applying these values to other areas of the watershed may
result in overestimated loadings.' It is hard to determine how these export
coefficients apply to areas of the watershed separated from the reservoir by a
different land use. Sediment eroded from one area may be subsequently filtered by
IV-6
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IV-7
Table IV-3
Export Coefficients for Soil Types B and C (lb/acre-yr)
Land Use Total Phosphorus Total Nitrogen
Category B C B C
Forest 0.08 0.08 0.6 0.6
Open 0.08 0.08 0.6 0.6
Pasture 0.5 0.5 2.6 2.6
Conservation Tillage 0.8 0.9 10.3 10.5
Conventional Tillage 4.7 5.6 15.9 17.3
Single Family Residential
Large Lot 0.4 0.4 4.4 4.1
Low Density 0.8 0.9 6.7 6.6
Low-Medium Density 1.0 1.0 8.0 8.0
Medium Density 1.1 1.1 8.8 8.8
Institutional 1.1 1.1 8.8 8.8
Townhouse/Apartment 1.6 1.7 12.9 13.1
Commercial/Office 1.6 1.6 13.2 13.2
Heavy Industry 1.3 1.3 11.3 11.2
Water 0.7 0.7 11.6 11.6
IV-8
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N-10

vegetation or may be redeposited before it enters the reservoir. In the case of
Randleman Lake, a 200-foot buffer zone would surround the reservoir. The effect
of this area on nutrient inputs is not considered in the loading calculations.
Therefore, the. methods used in this report probably overestimate the stormwater
loading of nutrients into the reservoir.
Tables IV-4 and IV-5 also present the baseflow loading and total loading for each
subbasin. Baseflow concentrations (Cb) of 35 ppb total phosphorus and 1,000 ppb
total nitrogen were used in the calculations. These concentrations were assumed to
be constant for all land use types. Baseflow quantity was calculated for each subbasin
by subtracting the calculated runoff (Rs) from a total runoff value (Rt) of 1.3 ft/yr.
This runoff value was derived from an average streamflow of 17 cfs measured for
subarea A shown on Figure III-1.
Nutrient loadings for future land use conditions are presented in Tables IV-6 and
IV-7. For this future development case the export coefficients remain the same. The
baseflow concentration of total phosphorus was assumed to be 80 ppb; the total
nitrogen concentration remained at 1,000 ppb.8 These estimates show that, under this
future land use pattern, phosphorus and nitrogen loadings in the watershed would
increase by 101 and 73 percent, respectively. The highest increases would occur in
the more urbanized areas.
C. Reservoir Response Model
Eutrophication is caused by the enrichment of a water body with nutrients which
leads to excessive growth of algae and other aquatic plants. Indicators or measures
of eutrophication include total nutrient concentrations, chlorophyll a content,
transparency (Secchi depth), and oxygen depletion. Water quality models are often
used as diagnostic or predictive tools to describe eutrophication in reservoirs. In this
study, an empirical model was used as a predictive tool to estimate the nutrient
enrichment and the degree of eutrophication that would be expected in Randleman
Lake.
1. BATHTUB Program
W.W. Walker developed a computer program called BATHTUB for the U.S.
Army Corps of Engineers to predict eutrophication in reservoirs.16 The basis of the
model is to relate eutrophication indicators to external nutrient loading, hydrology,
~ IV-11
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IV-12

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IV-13
and reservoir morphology. This is accomplished through a two-stage process. First,
the model calculates water and nutrient balances and resultant concentrations of
eutrophication indicators. In computing these balances, the model accounts for
advective and diffusive transport, and nutrient sedimentation. Then the water quality
response is calculated based on the relationships among eutrophication indicators
within the reservoir. The model uses empirical relationships previously developed for
other reservoirs to calculate the reservoir response. ",'g,'9 The calculations are
for steady-state conditions and assume spatial homogeneity within each segment.
The BATHTUB model can be configured to simulate a segmented reservoir or
networks of reservoirs. For the case of Randleman Lake, a model was configured
to include the two upstream reservoirs, Oak Hollow and High Point lakes, and six
segments in Randleman Lake. The Randleman Lake segmentation allows the model
to predict the spatial distribution of constituents within the reservoir. A schematic
diagram of the model configuration is presented on Figure N-3. The diagram shows
the locations of wastewater input and water withdrawals, and shows advective
transport between basins. Walker adapted the BATHTUB program to a spreadsheet
format specifically for this Randleman Lake study.
2. Input Data
The input parameters for the Randleman Lake eutrophication model include
hydrologic data, rainfall, evaporation, the physical characteristics of the reservoir,
nonpoint and point source volumes and concentrations of phosphorus and ortho-
phosphate, water withdrawal rates, and non-algal turbidity.
a. Hydrologic Factors. One of the objectives of this study was to develop a
frequency distribution of loadings and associated reservoir water quality that could
be expected based on the natural variations in rainfall and streamilow. -A 59-year
record of hydrologic data, discussed in Section III, was used as input to the eutrophi-
cation model. The model was run 59 times using annual averages of flow, rainfall,
and evaporation. Flows into Randleman Lake are reported to average approximately
100 mgd (155 cfs) ranging from about 50 mgd (78 cfs) during a low flow year to
about 200 mgd (310 cfs) during a high flow year. For this flow range, the
IV-14
WASTEWATER
TREATMENT PLANT
OAK
HOLLOW
LAKE
HIGH
P01 NT
LAKE
MUDDY DEEP
CREEK RIVER WATER
I I TREATMENT
PLANT
DEEP
RIVER
WATER MUDDY 2
TREATMENT CREEK
PLANT 2
DEEP
RIVER
3
DAM
AREA

:
RANDLEMAN LAKE
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
SCHEMATIC DIAGRAM OF THE
RESERVOIR WATER QUALITY MODEL
FIGURE IZ-3

hydraulic retention time (lake volume divided by inflow) on the lake would range
from about 0.5 years at low flow to 0.25 years at high flow, with an average of about
0.4 years.
b. Physical Characteristics. The drainage area, reservoir surface area, volume,
and segment length were calculated for each subbasin and entered into the model.
This information was developed from USGS topographic maps. A normal pool
t elevation of 682 feet was used and the values of these physical characteristics
remained constant for all model runs.
e. Rainfall and Runoff. The amount of stormwater runoff generated in an area is
dependent on the rainfall, soil type and absorption capacity, and the amow't'of
impervious surface. For impervious surfaces, it was assumed that 75 percent of the
rainfall becomes surface runoff. For pervious surfaces the amount of runoff depends
F on the soil types. For this study it was assumed that, during an average rainfall year
of 44 inches, surface runoff from Type B soils would be 3.5 inches and runoff from
z type C soils would be 5.3 inches.
These values were derived from data collected in northern Virginia Piedmont
basins and were used in the Watershed Management Plan for the upper watershed.8
To adjust these runoff values for years with other than the average rainfall, a ratio
of actual rainfall to average rainfall was used. For any year the runoff volume (Qs,
acre-ft) for an area (A., acres) can be calculated as the surface runoff (Rs, ft) times
the area, or:
(Eq.1) Qs=Rs*A=[P*0.75*Imp+P*0.11*(1-Imp)] *A
where P is precipitation and Imp is the fraction of impervious surface in area A. The
factor 0.11 is obtained by combining the precipitation ratio with the runoff amounts
and percentages of Type B and Type C sons. In other words,
0. 11 = [ 0.3 * 3.5 + 0.7 * 5.3 1 / 44.
Nutrients and other contaminants carried in stormwater or surface runoff would
contribute the majority of the nutrient loading to the reservoir. However, nutrients
carried in the baseflow also contribute to the total nutrient input. For this study,
IV-15
baseflow has been calculated as the difference between the measured streamflow for
the watershed, as developed in Section III, and the calculated surface runoff.
d. Stormwater Loading. Since the export coefficients developed previously are
based on average annual rainfall, they cannot be used directly to calculate loadings
for other than average years. Export coefficients can be expressed as concentration
times runoff. Using the calculated runoff (Rs) for an average year (Eq. 1), event
mean concentrations for phosphorus were calculated for each land use type. This can
be expressed as follows:
(Eq. 2) Loading (lb/yr) = EC * A = Cs * Rs * A or Cs = EC / Rs
where, EC is the export coefficient (lb/acre-yr) and Cs is the concentration of TP in
stormwater (lb/acre-ft).
By expressing the export coefficient in this way it is assumed that the con-
centration of total phosphorus in stormwater (Cs) is only a function of land use type
and is not affected by rainfall. This also means that the changes in loading are
dependent only on changes in runoff volume which is a function of rainfall and
imperviousness.
Since the stormwater concentration (Cs) is a function of land use type, an
average concentration can be determined for each subbasin. The concentration of
total phosphorus in stormwater was calculated for each subbasin using a weighted
average of event mean concentration and acres of each land use type in the subbasin.
These values, representing existing land use, were constant for the first set of model
runs using 59 years of flow data. A new set of concentrations were calculated based
on the future land use distribution (Table IV-2).
Stormwater runoff values were calculated, for 59 years of flow data and existing
land use, using the expression for stormwater runoff (Rs) in Equation 1. The
precipitation data used for these calculations were collected at Randleman. The
amount of impervious surface for each subbasin was calculated for each land use as
the weighted average of the percentage of impervious surface multiplied by acres.
This calculation was also performed for future land use, considering the predicted
changes in impervious surfaces.
IV-16
e. Total Nonpoint Source Loading. The total nonpoint source nutrient loading
would be a combination of stormwater and baseflow contributions. The total
nonpoint source loading can be expressed as:
(Eq.3) Loading= Qt*Ct=A*Rt*Ct=A*[Rs*Cs+Rb*Cb]
This can also be written as:
(Eq.4) Rt * Ct = Rs * Cs + Rb * Cb
where Ct is the concentration of nutrients in the combined flow and Cb is the
concentration of nutrients in the baseflow. As mentioned previously the baseflow was
calculated as the difference between measured streamflow and stormwater runoff or:
(Eq. 5) Rb = Rt - Rs
Since the precipitation and measured streamflow are not perfectly correlated, the
calculated Rs exceeded the measured streamflow during some low flow years.
Therefore, a limit was set so that Rs could not exceed Rt. In these cases, Rb was
zero; the total runoff was stormflow; and Ct was equal to Cs. Since there actually
would be baseflow during these low flow conditions, this formulation probably
overestimates loading for some low flow years.
Substituting Equation 5 into Equation 4 an equation for Ct was developed:
(Eq. 6) Ct = [Rs (Cs - Cb)/Rt] + Cb
The baseflow concentration is a constant and the stormwater concentration is a
constant for each subbasin and therefore Ct varies with Rs, i.e., precipitation and
imperviousness, and the total measured streamflow (Rt). Input values for Rt and Ct
corresponding to the 59 years of streamflow data and the existing land use are
presented in Appendix B (Table B-1). The calculated values of Cs for each subbasin
are also shown in Table B-1.
IV-17
Input values for Rt and Ct for the future land use condition are presented in
Appendix B, Table B-2. Under this condition, the amount of impervious surface
would increase and therefore the stormflow would also increase. These new values
were calculated according to Equation 1. In addition, the baseflow should decrease,
but it is not possible to determine the amount of decrease. As a conservative
estimate, the baseflow values calculated for the existing land use case were also used
for the future land use case. This means that the total streamflow values for the
future land use case were greater than the values used for the existing condition. For
the future case, the baseflow concentration of total phosphorus was assumed to
increase from 35 ppb to 80 ppb.
f. Point Source Loading. At present there are 42 permitted discharges into the
Randleman Lake watershed. Of these, the only significant source of nutrients is the
High Point Eastside Wastewater Treatment Plant which treats and discharges
wastewater from the city of High Point. Other discharges are discussed further in
Section V of this report.
It was estimated that the wastewater treatment plant discharges an average of
10.5 mgd. The average total phosphorus concentration of the effluent is 4,000 ppb
(4 milligrams per liter, mg/L). It was assumed that all of the phosphorus is in the
form of orthophosphate. The average total nitrogen concentration of the effluent is
23 mg/L. These averages were derived from monthly monitoring data collected from
January 1986 through December 1989. For the future case the wastewater flow rate
was assumed to increase to 16 mgd, the design capacity of the treatment plant.
3. Model Outputs
The model outputs include many variables which describe watershed
characteristics, reservoir characteristics, the water and total phosphorus balances, and
the reservoir response. In most cases, these values were calculated for each subbasin
and averages were also calculated for Randleman Lake. The constituents of most
interest to this Randleman Lake study are the mean total phosphorus concentration,
mean chlorophyll g concentration, algal nuisance frequency, mean Secchi depth, and
hypolimnetic oxygen depletion. The mean chlorophyll a concentration was calculated
as a growing season average. All other means were calculated as annual averages.
IV-18
D. Trophic State Parameters
All of the model results are based on the assumption that the reservoir has
reached a quasi steady-state condition. These results do not represent conditions that
would occur during the first few years after formation of the reservoir. After the
initial filling of the reservoir, there would likely be significant nutrient and organic
loading from bottom sediments. This condition would likely produce algal blooms
and oxygen depletion in the hypolimnion.
1. Existing Land Use Case
The predicted values for mean total phosphorus for the 59 year period, assuming
the existing land use distribution, are summarized in Table N-8. Values are
presented for each subbasin. A volume weighted average for Randleman Lake is
also shown. For this case, it was assumed that the Eastside WW TP is operating at
current treatment levels and discharges into the reservoir.
The Deep River 1 subbasin consistently has the highest predicted values. This
occurs because the subbasin has a large drainage area, experiences high nonpoint
loading, receives the effluent from the wastewater plant and has a relatively small
volume. The concentrations would decrease moving downstream because the total
loadings decrease, the volumes increase, and because nutrients are trapped in the
bottom sediments of the reservoir as particulates move downstream and settle. This
pattern is typical of long narrow reservoirs and is also seen in the Muddy Creek arm.
The subbasin with the lowest total phosphorus concentration is consistently Muddy
Creek 2, where the water intake is proposed to be located.
Figure N-4 shows the cumulative frequency distribution of values for Randleman
Lake and for the Muddy Creek 2 subbasin. The range of predicted values over the
59 year period would be relatively small. The range equals 27 percent of the mean
for Randleman Lake. This small range is a result of compensating factors. In
general, as the total runoff increases and the loading increases, the concentration (Ct)
often decreases because a higher portion of runoff would be from baseflow which has
a lower concentration. Although the loading increases, the residence time decreases
and inputs would be flushed through the reservoir at a faster pace.
The predicted values for chlorophyll a are also summarized in Table IV-8 and
represent growing season averages. These results show a spatial pattern that is simi-
lar to mean total phosphorus. The average value for the reservoir would be
23.2 ppb. Concentrations in the Deep River 1 subbasin are predicted to be well
N-19
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IV-20
above the nuisance criterion of 40 ppb. The lowest predicted values of chlorophyll a
are in the Muddy Creek 2 subbasin with an average value of 13 ppb. Figure IV-5
shows the cumulative frequency distribution of chlorophyll a values for Randleman
Lake and for the Muddy Creek 2 subbasin.
In addition to predicting growing season averages it is useful to determine the
amount of time that chlorophyll a values might exceed the nuisance criteria during
an individual growing season. This is expressed through the algal nuisance frequency
parameter. This is determined by applying a distribution curve to the mean and
calculating the percent of time that the curve exceeds the nuisance criteria. These
values are presented in Table IV-8. The predicted values of total phosphorus,
chlorophyll a and algal nuisance frequency for each year of flow data used are
presented in Appendix B (Tables B-3, B-4, and B-5).
2. Future Land Use Case
The model results for mean total phosphorus, mean chlorophyll a and algal
nuisance frequency for the future land use case are summarized in Table IV-9. The
spatial patterns are similar to those seen for the existing land use case. However, the
values are higher and the range is smaller. Figures IV-6 and IV-7 show the
cumulative frequency distributions for total phosphorus and chlorophyll a
respectively. Predicted values for each year of flow data used are presented in
Appendix B (Tables B-6, B-7, and B-8).
3. Special Cases
Several special cases were run on the model to examine the sensitivity of two
model input parameters and to address potential wastewater treatment plant
operational changes. For these special cases, a limited number of years were run.
The years selected were 1951 and 1967 to represent low flow, 1943 and 1953 for
average flow, and 1960 and 1975 to represent high flow. For most of the special
cases, the existing land use distribution was used. Table IV-10 shows model results
for these special case years and is presented for comparison with the special case
results. In addition to mean total phosphorus, chlorophyll a and algal nuisance
frequency, Secchi depth, and oxygen depletion values are also shown.
The first three special cases test the sensitivity of assumptions used in two model
input parameters. It was assumed that orthophosphate was equal to 30 percent of
total phosphorus for storm runoff and baseflow. There are insufficient data to
N-21

180
0 Mean TP-Existing Land Use-Rondlemon Lk
.
170.0
160.0
150.0
a 140.0
a
v
U 130.0
0 120.0
° 110.0
c
u 100.0
C
0
U 90.0
c
00 80.0

70.0
60.0
50.0
40
0
.
0 20 40 60 80 100
X of Mean Concentrations < C
Moon TP-Existing Land Use-Muddy Creek 2
180.0
170.0
160.0
150.0
a 140.0
a
U 130.0
0 120.0
° 110.0
c
u 100.0
c
0
v 90.0
c
80.0

70.0
60.0
50.0
40.0
0 20 40 60 80 100
X of Moon Concentrations < C
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
DISTRIBUTION OF
MEAN TOTAL PHOSPHORUS CONCENTRATIONS
FOR THE EXISTING LAND USE CASE
FIGURE IV-4

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IV-22
Mean Chl-a-Exist Land Use-Randleman Lk
25.0
24.0
23.0
22.0
D
n
21.0
u 20.0
c
Z
19.0
0
0 18.0
c
0
17.0
u
0 16.0
•

15.0
14.0
13.0
12.0
0 20 40 60 80 100
% of Meon Concentrations < C
Mean Chi-o-Existing Land Use-Muddy Ck 2
25.0
24.0
23.0
22.0
0
0.
21.0
u 20.0
c
19.6
0
0 18.0
c
0
17.0
u
0 16.0
0
15.0
14.0
13.0
12.0
0 20 40 60 so 100
% of Mean Concentrations < C
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
DISTRIBUTION OF
MEAN CHLOROPHYLLA CONCENTRATIONS
FOR THE EXISTING LAND USE CASE
FIGURE IV-5

1
00 Meon TP-Future Land Use-Rondlemon Lk
8
170.0
1600
1500
a, 140.0
a.
U 130.0
0 120.0
110.0
c
100.0
c
0
U 90.0
c
0 80.0

70.0
600
50.0
40
0
.
0 20 40 60 80 100
X of Mean Concentrations < C
Mean TP-Future Land Use-Muddy Crook 2
180.0
170.0
160.0
1500
D 1400
0.
U 130.0
0 1200 .
110.0
c
u 100.0
c
0
U 90.0
c
S 80.0

70.0
60.0
50.0
400
0 20 40 60 e0 100
X of Mean Concentrations < C
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
DISTRIBUTION OF
MEAN TOTAL PHOSPHORUS CONCENTRATIONS
FOR THE FUTURE LAND USE CASE
FIGURE IV -6

25
0 Mean Chl-o-Future Land Use-Rondlemon Lk
.
24.0
23.0
22.0
a
a 21.0
u 20.0
c
0
19.0
0
c 18.0
c
0 17.0
U
0 16.0
0

15.0
14.0
13.0

12.0
0 20 40 60 80 100
S of Mean Concentrations < C
Moon Chi-o-Future Land Use-Muddy Ck 2
25.0
24.0
23.0
22.0
a
Q. 21.0
u 20.0
c
0
-
19.0
0
0 18.0
c
0 17,0
U
0 16.0
0

15.0
14.0
13.0
12.0
0 20 40 60 BO 100
R of Mean Concentrations < C
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
DISTRIBUTION OF
MEAN CHLOROPHYLLA CONCENTRATIONS
FOR THE FUTURE LAND USE CASE
FIGURE IV-7
Table IV-10
Results for Special Case Years and Existing Land Use Conditions
Oak High Pt Deep Deep Deep Muddy Muddy Dam Randleman
Hollow Lake River 1 River 2 River 3 Creek 1 Creek 2 Area Lake Year
Mean Pbosphorus (ppb)
67.7 72.6 1233.4 282.9 89.2 93.1 42.9 48.4 156.8 1951
67.4 71.2 1429.1 290.1 87.6 92.7 43.6 47.2 166.0 1967
57.0 66.1 913.7 258.0 92.7 74.3 42.9 53.1 139.2 1943
55.9 65.2 870.9 257.3 94.3 73.7 433 54.4 138.1 1953
52.0 61.6 668.0 240.5 99.0 673 43.2 60.2 128.6 1960
57.2 67.1 655.9 240.5 99.2 72.0 44.1 60.8 128.7 1975
Mean Chlorophyll-a (ppb)
22.1 25.6 93.5 33.9 19.6 27.1 13.1 14.2 23.6 1951
22.3 26.1 94.6 34.2 19.5 27.2 13.3 14.0 23.6 1%7
19.6 22.7 90.4 32.8 19.5 23.8 12.9 14.9 23.1 1943
19.2 22.1 89.8 32.7 19.6 23.6 13.0 15.1 23.1 1953
17.9 19.3 85.6 31.4 19.4 21.9 12.7 15.6 22.6 1960
19.1 19.9 85.0 31.2 19.3 22.7 12.8 15.6 22.6 1975
Algal Nuisance Frequency ( % )
93 143 88.6 28.2 6.2 16.7 1.2 1.8 12.6 1951
9.4 15.1 89.0 28.8 6.2 16.8 13 1.7 12.7 1967
6.2 10.1 87.4 26.3 6.1 115 1.2 2.2 11.9 1943
5.8 9.2 87.2 26.1 6.2 113 1.2 23 11.9 1953
4.5 5.9 85.3 23.9 6.0 9.0 1.1 2.6 11.3 1960
5.7 6.6 85.0 23.6 5.9 10.1 1.1 2.6 11.3 1975
Secchi Depth (m)
1.05 0.96 0.37 0.80 1.12 0.93 1.37 1.32 1.10 1951
1.05 0.95 036 0.80 1.13 0.93 1.37 1.33 1.10 1967
1.13 1.03 0.38 0.82 1.13 1.01 1.38 1.30 1.10 1943
1.14 1.05 0.38 0.82 1.12 1.01 1.38 1.29 1.10 1953
1.18 1.13 0.39 0.84 1.13 1.05 139 1.27 1.10 1960
1.14 1.11 0.40 0.85 1.13 1.03 1.39 1.27 1.10 1975
Oxygen Depletion (mg/m2-d)
1,129 1,215 1,165 1951
1,132 1,226 not calculated for individual subbasins 1,167 1967
1,061 1,144 1,154 1943
1,052 1,128 1,154 1953
1,015 1,054 1,142 1960
1,049 1,072 1,141 1975
Oxygen Depletion (mg/m3-d)
568 688 293 1951
570 694 not calculated for individual subbasins 293 1967
534 647 290 1943
530 638 290 1953
511 597 287 1960
528 606 287 1975
IV-23
establish this value with certainty. Table IV-11 presents results of the model
assuming that the orthophosphate was increased to equal 50 percent of the total
phosphorus. The results show only slightly higher values for the listed parameters.
Non-algal turbidity is another input parameter required by the model. This term
can be thought of as the inverse of the Secchi depth without the influence of algae
in the water. This can be calculated from Secchi depth and chlorophyll a data for
existing reservoirs. However, for Randleman Lake, some assumed value must be
used. The value of 0.4 was considered to be a typical value and was used in the
previous model runs. Walker developed an equation for calculating this term based
on empirical data for phosphorus concentration, flushing rate, depth, and latitude.
Using this equation, a value of 0.7 was calculated. Table IV-12 shows the model
results using the value of 0.7 for non-algal turbidity. Using this value, slightly lower
values of total phosphorus, chlorophyll a and oxygen depletion are predicted. The
Secchi depth, however, decreases. Using a higher value of non-algal turbidity means
that the natural turbidity in the water would decrease the amount of light available
for algal growth, thereby reducing growth. Table IV-13 shows the model results using
a lower value, 0.2 for non-algal turbidity. All parameters except mean phosphorus
are slightly higher. Comparing the three sets of results generated for different non-
algal turbidity values indicates that the model is not extremely sensitive to this
parameter.
The fourth special case assumes that the concentration of phosphorus in the
wastewater effluent is reduced from 4,000 ppb to 1,000 ppb. The flow remains at
10.5 mgd and all other inputs remain the same. The most noticeable effect of this
change is the 58 percent reduction of total phosphorus in the Deep River 1 subbasin
(Table IV-14). Average phosphorus values for Randleman Lake would be reduced
by almost 40 percent. Values in Muddy Creek 2 would decrease by about 10 percent.
The effects that this change would have on the other listed parameters is not as
pronounced, with subbasin and average reservoir values decreasing by about 10
percent or less.
The fifth special case assumes that the concentration of total phosphorus in the
effluent is reduced to 500 ppb. The results of this case are shown in Table IV-15.
As with the first case, the most dramatic changes occur in the phosphorus concen-
tration in the Deep River 1 subbasin where a 71 percent reduction is predicted.
Total phosphorus reduction in Muddy Creek 2 and Randleman Lake would be 14
IV-24

C

Table N-11
Assume that Orthophosphate equals 50 percent of Total Phosphorus
Oak High Pt Deep Deep Deep Muddy Muddy Dam Randleman
Hollow Lake River 1 River 2 River 3 Creek 1 Creek 2 Area Lake Year
Mean Phosphorus (ppb)
82.6 89.1 1243.7 287.8 91.1 114.6 45.8 50.1 161.1 1951
81.9 87.1 1438.1 294.8 89.7 114.5 46.7 49.2 170.4 1%7
70.1 823 927.2 263.2 94.8 928 46.3 54.9 143.6 1943
68.9 81.4 884.8 262.7 965 922 46.7 56.3 142.6 1953
64.8 78.1 683.7 246.9 101.5 853 47.1 622 133.5 1960
71.1 85.2 674.0 247.8 102.1 91.5 48.7 63.0 134.3 1975
Mean Chlorophyll-a (ppb)
24.7 28.8 93.6 34.0 19.7 29.7 13.7 14.6 24.0 1951
24.8 29.4 94.6 343 19.7 29.8 13.9 14.4 24.1 1967
22.3 25.8 90.4 32.9 19.7 26.7 13.6 15.2 23.6 1943
22.0 25.1 89.9 328 19.7 265 13.7 153 23.6 1953
20.7 22.0 85.8 315 19.6 25.0 135 15.9 23.1 1960
21.8 22.5 85.2 31.4 195 25.7 13.7 15.9 23.1 1975
Algal Nuisance Frequency ( % )
12.9 19.4 88.6 28.4 6.4 20.9 1S 20 13.1 1951
13.1 20.5 89.0 28.9 6.4 21.1 1.6 1.9 13.2 1%7
9.5 14.6 87.4 265 63 15.9 1.5 24 124 1943
9.1 135 87.2 26.3 6.4 15.7 1.5 25 12.4 1953
7.4 9.2 85.4 24.1 6.2 133 1.4 2.8 11.8 1960
8.9 9.8 85.1 23.8 6.1 14.4 1.5 28 11.8 1975
Secchi Depth (m)
0.98 0.89 0.37 0.80 1.12 0.88 135 131 1.10 1951
0.98 0.88 036 0.80 1.12 0.87 134 131 1.10 1967
1.05 0.96 038 0.82 1.12 0.94 135 1.28 1.10 1943
1.05 0.97 038 0.82 1.12 0.94 135 1.28 1.10 1953
1.09 1.05 039 0.84 1.13 0.98 1.36 1.26 1.10 1960
1.06 1.04 0.40 0.84 1.13 0.96 135 1.25 1.10 1975
Oxygen Depletion (mg/m2-d)
1,193 1,288 1,175 1951
1,196 1,301 not calculated for individual subbasins 1,178 1967
1,133 1,219 1,165 1943
1,125 1,203 1,165 1953
1,091 1,127 1,154 1960
1,121 1,139 1,154 1975
Oxygen Depletion (mg/m3-d)
600 729 295 1951
602 736 not calculated for individual subbatins 296 1967
570 690 293 1943
566 681 290 1953
549 638 293 1960
564 644 290 1975
N-25
Table IV-12
Assume that Non-Algal Turbidity equals 0.7 (1/m)
Oak High Pt Deep Deep Deep Muddy Muddy Dam Randleman
Hollow Lake River 1 River 2 River 3 Crock 1 Creek 2 Area We Year
Mean Phosphorus (ppb)
67.7 726 1233.4 282.9 89.2 93.1 42.9 48.4 156.8 1951
67.4 71.2 1429.1 290.1 87.6 927 43.6 47.2 166.0 1%7
57.0 66.1 913.7 258.0 92.7 743 429 53.1 139.2 1943
55.9 65.2 870.9 257.3 94.3 73.7 433 54.4 138.1 1953
52.0 61.6 668.0 240.5 99.0 673 43.2 60.2 128.6 1960
57.2 67.1 655.9 240.5 99.2 720 44.1 60.8 128.7 1975
Mean Chlorophyll-a (ppb)
18.8 221 85.4 28.7 16.1 23.1 10.7 11.7 19.9 1951
18.9 226 86.4 28.9 16.0 23.2 10.9 11.5 20.0 1%7
16.6 19.4 82.4 27.7 16.0 20.2 10.6 122 19.5 1943
163 18.8 81.9 27.6 16.0 20.1 10.6 123 195 1953
15.1 16.2 77.9 26.4 15.8 18.6 103 127 19.0 1960
16.1 16.7 773 26.2 15.7 193 10.4 12.7 19.0 1975
Algal Nuisance Frequency( % )
5.4 9.2 85.2 19.2 3.0 10.6 03 0.7 9.1 1951
5-5 9.9 85.7 19.7 3.0 10.7 OS 0.7 9.2 1967
3.4 6.0 83.7 17.6 29 6.9 0.4 0.9 BS 1943
3.1 5.4 83.4 17.4 29 6.8 0.4 0.9 8.4 1953
23 3.1 81.2 15.5 28 5.2 0.4 1.1 7.9 1960
3.0 3.5 80.8 15.3 27 5.9 0.4 1.1 7.8 1975
Secchi Depth (m)
0.85 0.80 035 0.71 0.91 0.78 1.03 1.01 0.90 1951
0.85 0.79 035 0.70 0.91 0.78 1.03 1.01 0.90 1967
0.90 0.84 036 0.72 0.91 0.83 1.04 1.00 0.90 1943
0.90 0.85 036 0.72 0.91 Offi 1.04 0.99 0.90 1953
0.93 0.90 038 0.74 0.91 0.86 1.04 0.98 0.90 1960
0.91 0.89 038 0.74 0.91 0.85 1.04 0.98 0.90 1975
Oxygen Depletion (mg/m2-d)
1,040 1,128 1,071 1951
1,044 1,141 not calculated for individual subbasins 1,073 1967
977 1,057 1,059 1943
969 1,041 1,060 1953
933 966 1,046 1960
963 981 1,046 1975
Oxygen Depletion (mg/m3-d)
S23 638 269 1951
525 646 not calculated for individual subbasins 270 1967
492 598 266 1943
487 589 266 1953
469 547 263 1960
485 555 263 1975
IV-26
Table IV-13
Assume that Non-Algal Turbidity equals 0.2 (1/m)
Oak High Pt Deep Deep Deep Muddy Muddy Dam Randleman
Hollow IAke River 1 River 2 River 3 Creek 1 Creek 2 Area Lake Year
Mean Phosphorus (ppb)
67.7 72.6 1233.4 282.9 89.2 93.1 42.9 48.4 156.8 1951
67.4 71.2 1429.1 290.1 87.6 92.7 43.6 47.2 166.0 1967
57.0 66.1 913.7 258.0 92.7 743 42.9 53.1 139.2 1943
55.9 65.2 870.9 257.3 943 73.7 433 54.4 138.1 1953
52.0 61.6 668.0 240.5 99.0 673 43.2 60.2 128.6 1960
57.2 67.1 655.9 240.5 99.2 72.0 44.1 60.8 128.7 1975
Mean Chlorophyll-a (ppb)
25.1 28.7 99.8 38.6 22.9 30.6 153 16.7 26.9 1951
25.2 29.1 100.9 38.9 22.9 30.7 155 16.4 26.9 1967
22.2 25.6 96.6 37.4 229 26.9 15.2 17.4 26.4 1943
21.9 25.0 96.0 37.3 23.0 26.7 15.2 17.7 26.5 1953
20.4 22.1 91.6 35.9 22.8 24.9 14.9 18.4 26.0 1960
21.8 22.9 91.0 35.8 22.7 25.8 15.1 18.4 26.0 1975
Algal Nuisance Frequency ( % )
13.5 19.3 90.7 36.4 10.4 226 25 3.4 16.4 1951
13.7 20.0 91.0 37.0 103 22.7 2.6 3.2 165 1967
9.4 143 89.6 34.4 10.3 163 23 4.1 15.7 1943
8.9 133 89.4 34.2 10.4 16.0 2.4 43 15.7 1953
7.1 93 87.9 31.8 10.2 13.2 2.2 4.9 15.1 1960
8.8 10.3 87.6 31.5 10.1 14.6 23 5.0 15.1 1975
Secchi Depth (m)
1.21 1.09 037 0.86 1.29 1.04 1.71 1.62 130 1951
1.20 1.08 037 0.85 130 1.03 1.70 1.64 130 1967
132 1.19 0.38 0.88 1.29 1.15 1.73 1.57 130 1943
1.34 1.21 038 0.88 1.29 1.15 1.72 156 1.30 1953
1.41 133 0.40 0.91 130 1.22 1.74 152 130 1960
1.34 1.29 0.40 0.91 1.30 1.18 1.73 152 130 1975
Oxygen Depletion (mg/mU)
1,202 1,285 1,244 1951
1,205 1,295 not calculated for individual gubbasins 1,246 1967
1,131 1,215 1,234 1943
1,122 1,200 1,235 1953
1,084 1,129 1,224 1960
1,120 1,149 1,224 1975
Oxygen Depletion (ng/m3-d)
605 727 313 1951
606 733 not calculated for individual subbasins 313 1%7
569 687 310 1943
565 679 310 1953
545 639 307 1960
563 650 308 1975
IV-27
Table N-14
Total Phosphorus Concentration of Wastewater Treatment
Plant Effluent is Reduced to 11000 ppb
Oak High Pt Deep Deep Deep Muddy Muddy Dam Randleman
Hollow Lake River 1 River 2 River 3 Meek 1 Creek 2 Area Lake Year
Mean Phosphorus (ppb)
67.7 72.6 527.0 176.8 68.1 93.1 38.5 41.1 97.9 1951
67.4 71.2 624.1 185.1 68.2 927 395 41.0 103.8 1967
57.0 66.1 375.6 1528 67.7 743 383 43.4 86.1 1943
55.9 65.2 354.7 150.8 68.3 73.7 385 44.1 85.2 1953
520 61.6 2626 133.5 68.2 673 383 46.6 78.2 1960
57.2 67.1 264.1 136.2 693 72.0 39.7 475 79.9 1975
Mean Chlorophyll-a (ppb)
22.1 25.6 87.6 31.2 173 27.1 121 127 21.6 1951
223 26.1 89.8 31.7 17.4 27.2 124 127 21.9 1%7
19.6 227 81.7 29.5 17.0 23.8 11.9 13.0 20.8 1943
19.2 22.1 80.6 29.3 17.0 23.6 11.9 13.1 20.7 1953
17.9 193 73.2 27.6 16.6 21.9 11.6 133 19.8 1960
19.1 19.9 73.0 27.6 16.7 227 11.9 135 20.0 1975
Algal Nuisance Frequency ( % )
9.3 143 86.2 23.5 4.0 16.7 0.9 1.1 10.8 1951
9.4 15.1 87.2 24.4 4.1 16.8 1.0 1.1 11.0 1967
6.2 10.1 83.4 20.7 3.7 115 0.8 1.2 9.7 1943
5.8 9.2 82.7 20.3 3.7 113 0.8 13 9.6 1953
4.5 5.9 78.1 17.4 3.4 9.0 0.7 1.4 8.6 1960
5.7 6.6 78.0 17.4 3.4 10.1 0.8 1.4 8.8 1975
Secchi Depth (m)
1.05 0.96 039 0.85 1.10 0.93 1.42 139 1.20 1951
1.05 0.95 038 0.84 1.10 0.93 1.41 139 1.20 1%7
1.13 1.03 0.41 0.88 1.21 1.01 1.44 138 1.10 1943
1.14 1.05 0.41 0.88 1.21 1.01 1.43 137 1.10 1953
1.18 1.13 0.45 0.92 1.23 1.05 1.45 136 1.20 1960
1.14 1.11 0.45 0.92 1.22 1.03 1.43 136 1.20 1975
Oxygen Depletion (mgha2-d)
1,129 1,215 1,115 1951
1,132 1,226 not calculated for individual subbasins 1,122 1967
1,061 1,144 1,093 1943
1,052 1,128 1,092 1953
1,015 1,054 1,069 1960
1,049 1,072 1,073 1975
Oxygen Depletion (mom-0)
568 688 280 1951
570 694 not calculated for individual subbasins 282 1%7
534 647 275 1943
530 638 274 1953
511 597 269 1960
528 606 270 1975
IV-28
Table IV-15
Total Phosphorus Concentration of Was tewater Treatment
Plant Effluent is Reduced to 500 ppb
Oak High Pt Deep Deep Deep Muddy Muddy Dam Randleman
Hollow Lake River 1 River 2 River 3 Meek 1 Creek 2 Area Lake Year
Mean Phosphorus (ppb)
67.7 72.6 3455 140.6 59.6 93.1 36.6 38.0 79.9 1951
67.4 71.2 409.8 148.1 60.3 92.7 37.7 38.2 84.5 1%7
57.0 66.1 248.6 119.8 58.4 743 363 395 70.6 1943
55.9 65.2 235.0 117.9 58.8 73.7 36.6 40.1 69.9 1953
52.0 61.6 176.5 103.7 58.0 673 36.4 41.6 645 1960
572 67.1 264.1 136.2 693 72.0 39.7 47.5 79.9 1975
Mean Chlorophyll-a (ppb)
22.1 25.6 81.8 29.4 16.2 27.1 11.6 12.0 20.4 1951
22.3 26.1 84.9 30.0 16.3 27.2 11.9 12.1 20.8 1%7
19.6 22.7 74.1 27.4 15.7 23.8 11.4 12.1 19.4 1943
19.2 22.1 72.6 27.2 15.7 23.6 11.4 12.3 19.3 1953
17.9 193 64.0 25.3 15.3 21.9 11.2 12.4 18.3 1960
19.1 19.9 73.0 27.6 16.7 22.7 11.9 13.5 20.0 1975
Algal Nuisance Frequency ( % )
9.3 143 83.4 20.4 3.0 16.7 0.7 0.8 9.7 1951
9.4 15.1 85.0 21.4 3.2 16.8 0.8 0.8 10.0 1%7
6.2 10.1 78.7 17.2 2.7 115 0.6 0.9 85 1943
5.8 9.2 77.7 16.8 2.7 113 0.7 0.9 83 1953
4.5 5.9 70.5 13.8 2.4 9.0 0.6 0.9 7.2 1960
5.7 6.6 78.0 17.4 3.4 10.1 0.8 1.4 8.8 1975
Secchi Depth (m)
1.05 0.% 0.41 0.88 124 0.93 1.45 1.43 1.20 1951
1.05 0.95 0.40 0.87 124 0.93 1.43 1.43 1.20 1%7
1.13 1.03 0.44 0.92 1.26 1.01 1.46 1.42 1.20 1943
1.14 1.05 0.45 0.93 1.26 1.01 1.46 1.42 1.20 1953
1.18 1.13 OSO 0.97 1.28 1.05 1.47 1.41 1.20 1960
1.14 1.11 0.45 0.92 1.22 1.03 1.43 1.36 1.20 1975
Oxygen Depletion (mg/m2-d)
1,129 1,215 1,084 1951
1,132 1,226 not calculated for individual subbasins 1,094 1%7
1,061 1,144 1,056 1943
1,052 1,128 1,054 1953
1,015 1,054 1,026 1960
1,049 1,072 1,073 1975
Oxygen Depletion (mg/m3-4)
568 688 272 1951
570 694 not calculated for individual subbasins 275 1967
534 647 265 1943
530 638 265 1953
511 597 258 1960
528 606 270 1975
IV-29

and 48 percent, respectively. Changes in other constituents range from about 10 to
15 percent for subbasin and reservoir averages.
The sixth special case assumes that the wastewater treatment plant effluent is
removed from the reservoir and discharged downstream of the dam. As expected,
substantial reductions in phosphorus concentrations are seen (Table IV-16). The
reservoir average decreases by about 60 percent. The reservoir averages for
chlorophyll a and algal nuisance frequency decrease by about 30 percent and 50
percent respectively. Predicted changes are relatively small for the Muddy Creek 2
subbasin, since this basin had the lowest concentrations under the existing conditions
case.
The special cases discussed above assumed the existing land use distribution.
Three additional special cases were run assuming the future land use distribution.
The first assumes that the treatment plant discharge is eliminated. These results are
shown in Table IV-17. By comparing these results to those presented in Table N-16,
the effects of the land use changes can be seen.
It is estimated that the total phosphorus and chlorophyll a concentrations of
Randleman Lake would increase by 23 percent and 16 percent respectively, due to
changes in the land use. This corresponds to an increase in the impervious surface
for the watershed from 11.4 percent, for the existing land use distribution, to 32
percent, for the future scenario. Even without the East Side WWTP the Deep River
1 subbasin would have high levels of phosphorus and chlorophyll a. However, the
Muddy Creek 2 subbasin and the reservoir as a whole would not be eutrophic and
are predicted to have chlorophyll a levels less than 20 ug/L.
The previous results shown for the future land use distribution (Table IV-9)
assumed that the treatment plant was discharging 16 mgd with a total phosphorus
concentration of 4 mg/L. This scenario was based on using the full capacity of the
treatment plant without changing the treatment process. However, based on the
relationship between water usage and wastewater generation, discussed in Chapter
III, it is estimated that up to approximately 20 mgd of wastewater could be returned
to Randleman Lake. This includes 12 mgd of High Point's wastewater associated
with the yield's from Oak Hollow and High Point lakes and an additional 5.9 mgd
from High Point's share of the Randleman Lake Yield. Also included is 2.2 mgd of
wastewater from Archdale and Jamestown's shares of the Randleman Lake yield,
which was assumed to be treated by High Point. It is not known if an expanded
treatment plant would be allowed in the reservoir watershed. However, it is
IV-30
Table IV-16
The Wastewater Treatment Discharge is Elimin ated
Oak Higb Pt Deep Deep Deep Muddy Muddy Dam Randleman
Hollow Lake River 1 River 2 River 3 Geer 1 Creek 2 Area Lake Year
Mean Phosphorus (ppb)
67.7 72.6 139.6 87.3 44.4 98.8 33.9 32.2 55.3 1951
67.4 71.2 162.6 90.9 45.3 101.1 35.9 33.6 58.0 1%7
57.0 66.1 112.2 75.1 43.5 75.9 33.3 32.6 50.0 1943
55.9 65.2 107.8 74.3 43.8 75.1 33.6 33.0 49.9 1953
52.0 61.6 88.8 67.5 43.4 67.9 33.6 33.9 47.5 1960
57.2 67.1 995 74.2 465 725 36.0 36.0 513 1975
Mean Chlorophyll-a (ppb)
221 25.6 59.7 24.6 135 28.0 10.9 10.5 173 1951
22.3 26.1 64.6 25.2 13.7 28.4 115 10.9 18.0 1%7
19.6 22.7 52.0 22.4 13.1 24.1 10.7 105 16.2 1943
19.2 22.1 50.6 222 13.1 23.9 10.7 10.6 16.1 1953
17.9 193 43.7 20.6 12.8 22.1 10.5 10.6 153 1960
19.1 19.9 47.1 21.6 13.3 22.9 11.1 11.1 16.0 1975
Algal Nuisance Frequency ( % )
93 143 66.2 12.7 1.4 18.1 OS 0.4 7.1 1951
9.4 15.1 71.1 13.6 1.5 18.8 0.7 OS 7.6 1967
6.2 10.1 57.0 9.7 1.2 12.1 OS 0.4 5.6 1943
5.8 9.2 55.1 9.4 13 11.8 OS 0.4 5.5 1953
4.5 5.9 44.8 7.4 1.1 9.2 0.4 0.4 4.4 1960
5.7 6.6 50.0 8.6 13 103 0.6 0.6 5.1 19721'
SeccW Depth (m)
1.05 0.% 0.53 0.99 1.36 0.91 1.48 151 130 1951
1.05 0.95 0.50 0.97 1.35 0.90 1.45 1.49 1.30 1%7
1.13 1.03 0.59 1.04 1.38 1.00 1.50 151 130 1943
1.14 1.05 0.60 1.05 1.37 1.00 150 151 130 1953
1.18 1.13 0.67 1.09 139 1.05 151 150 130 1960
1.14 1.11 0.63 1.06 136 1.03 1.48 1.48 130 1975
Oxygen Depletion (mg/m2.d)
1,129 1,215 999 1951
1,132 1,226 not calculated for individual subbasins 1,017 1%7
1,061 1,144 966 1943
1,052 1,128 964 1953
1,015 1,054 938 1960
1,049 1,072 %1 1975
Oxygen Depletion (mg/m3-d)
568 688 251 1951
570 694 not calculated for individual subbasins 256 1%7
534 647 243 1943
530 638 242 1953
511 597 236 1960
528 606 241 1975
N-31
Table IV-17
Future Land Use Conditions - WWTP flow is eliminated
Oak
Hollow High Pt
Lake Deep
River 1 Deep
River 2 Deep Muddy
River 3 Creek 1 Muddy
Creek 2 Dam
Area Randleman
LAke
Year
Mean Phosphorus (Vpb)
BSS
82.7
79.1
78.9
78.0
83.9 101.6
95.1
95.4
955
955
102.7 153.0
152.9
1353
133.4
1235
133.1 106.0
1025
975
97.6
95.7
102.7 563 95.9
53.1 93.2
54.9 87.6
55.7 87.7
58.4 85.7
62.2 90.7 38.9
375
38.7
39.2
413
44.0 39.9
375
39.9
40.7
44.0
46.8 65.3
62.7
62.0
62.4
635
67.8 1951
1967
1943
1953
1960
1975

Mean Chlo h 1-a (PPb)
245
24.4
233
23.2
22.4
23.1 16.9
27.7
24.9
14.3
215
21.0 61.4
61.9
572
56.6
53.2
55.0 26.1
26.1
25.0
24.9
24.1
245 15.4 27.0
15.0 26.9
15.0 25.6
15.1 25.6
15.1 24.6
155 25.1 12.0
11.8
11.8
11.9
12.1
12.6 12.2
11.8
12.1
123
12.7
13.1 18.8
185
18.2
18.2
18.0
185 1951
1967
1943
1953
1960
1975

Alg al Nuisance Frequency %
12.7
125
10.9
10.7
9.6
105 163
17.7
13.2
123
8.4
7.9 67.9
685
63.4
62.7
585
60.8 15.1
15.0
13.4
133
12.0
12.7 2S 165
2.2 16.4
22 143
23 142
23 12.8
2.6 135 0.8
0.8
0.8
0.8
0.9
1.0 0.9
0.8
0.9
0.9
1.1
12 7.9
7.8
7.2
72
6.7
7.1 1951
1967
1943
1953
1960
1975

Secchi De nth m
0.99
0.99
1.02
1.02
1.04
1.02 0.93
0.91
0.98
0.99
1.07
1.08 052
051
055
055
058
056 0.95
0.95
0.98
0.98
1.00
0.99 128 0.93
129 0.93
129 0.96
129 0.96
129 0.98
1.27 0.97 1.43
1.44
1.44
1.43
1.42
1.40 1.42
1.44
1.42
1.42
139
137 1.20
120
120
120
1.20
120 1951
1967
1943
1953
1960
1975

O xyzen Depletion (mz/m2-d )
1,187

1,159
1,155
1,136
1.152 1,264,244

1,198
1,184
1,112
1,100
not calculated for individual subbasins
1,0 041
1,023
1,024
1,017
1,031
1967
1943
1953
1960
1975

O pren D eviction m m3-0
598
597
583

581
571
580 704
715
678

670
629
623
not calculated for individual subbasins 262
260

257
257
256
259 1951
196
7
1943
1953
1960
1975
N-32

reasonable to assume that, if allowed, lower concentrations of phosphorus would be
required. Therefore, two special cases were run assuming that, in the future, the
East Point WWTP would be expanded to 20 mgd, and that the total phosphorus
concentration of the effluent would be reduced to 1,000 ppb or 500 ppb of
phosphorus. The results of these two cases are presented in Tables IV-18 and IV-19,
respectively.
Under these two scenarios, the Deep River 1 subbasin is predicted to be highly
eutrophic while the Muddy Creek 2 subbasin would have very good water quality.
The model results presented in Tables IV-18 and IV-19 show better water quality
than the existing land use and future land use cases presented previously in Table IV-
8 through IV-10. This is due to the reduced phosphorus concentration in the
wastewater effluent.
4. Comparison with Other Lakes
To put the water quality results in perspective, it is useful to compare the model
values with values measured in other regional reservoirs and lakes. Table IV-20
presents Secchi depth, total phosphorus, chlorophyll a and size data for eight regional
lakes(21) and values for Randleman Lake. The Randleman Lake values assume that
the total phosphorus concentration in the effluent is reduced to 0.5 mg/L.
The surface area of Randleman Lake would be much smaller than the Jordan
and Falls reservoirs but comparable in size to the other lakes.
Secchi depth, total phosphorus and chlorophyll a predicted for Randleman Lake
are within the range of values measured in the other lakes.
IV-33
Table IV-18
Future Land Use Conditions - WWTP flow is 20 mgd and Total
Phosphorus Concentration equals1000 b
Oak
Hollow High Pt
lake Deep
River 1 Deep
River 2 Deep Muddy
River 3 Creek 1 Muddy
Creek 2 Dam
Area Randleman
Lake
Year

Mean Ph horns (p pb)
855
82.7
79.1
78.9
78.0
83.9 101.6
95.1
95.4
955
955
102.7 487.2
555.8
436.6
4205
344.3
336.4 2055
212.7
193.8
192.3
179.7
181.4 86.6 92.7
84.8 88.4
86.4 85.7
873 86.0
89.6 84.9
91.6 90.0 44.2
43.1
44.0
44.4
45.7
475 53.6
50.9
54.8
55.8
60.2
62.1 110.9
1135
106.3
105.9
102.3
104.0 1951
1967
1943
1953
1960
1975

Mean Chlo h I-a (V pb)
2,43
24.4
23.3
23.2
22.4
23.1 26.9
27.7
24.9
24.3
215
21.0 84.3
86.8
82.1
81.3
76.3
75.2 31.2
31.9
30.5
30.3
29.0
28.8 18.8 26.4
18.9 26.1
18.6 25.2
18.6 25.2
183 24.4
18.2 24.9 13.1
13.0
12.9
13.0
12.9
13.2 14.8
145
14.9
15.0
15.3
15.4 22.6
22.7
22.2
22.1
21.6
21.6 1951
1967
1943
1953
1960
1975

Al I Nuisance Frequency %n
12.7
12-5
10.9
10.7
9.6
105 16.3
17.7
13.2
12.3
8.4
7.9 84.7
85.9
83.6
83.1
80.2
795 23.6
24.7
22.4
22.1
19.8
19.4 5.4 15.6
55 15.0
5.2 13.7
5.2 13.6
4.8 12.4
4.8 13.1 1.2
1.2
1.2
1.2
1.2
1.3 2.1
2.0
2.2
2.2
2.4
25 11.4
115
10.9
10.8
10.2
10.1 1951
1967
1943
1953
1960
1975

Secchi Depth m
0.99
0.99
1.02
1.02
1.04
1.02 0.93
0.91
0.98
0.99
1.07
1.08 0.40
039
0.41
0.41
0.43
0.44 015
0.84
0.86
0.86
0.89
0.89 1.15 0.94
1.15 0.95
1.16 0.97
1.16 0.97
1.17 0.99
1.17 0.98 138
138
138
138
138
137 130
131
130
1.29
1.28
1.28 1.10
1.10
1.10
1.10
1.10
1.10 1951
1967
1943
1953
1960
1975

O won Depletion m m2-d
1189 1,187

1,159
1,155
11136
1.152 1?

1,198
1,184
1,112
1,100 not calculated for individual subbasins 1140
,1043
1,130
1,129
1,115
1,115 1951
1967
1943
1953
1960
1975

O xygen Depletion m m3-d
598
597
583
581
571
580 704
715
678
670
629
623
not calculated for individual subbasins 286
287
284
284
280
280 1951
1%7
1943
1953
1%0
1975 11
IV-34
Table IV-19
Future Land Use Conditions - WNVTP flow
Total Phosphorus Concentration equals is 20
500 mgd and
b
Oak
Hollow High Pt
Lake Deep
River ] Deep
River 2 Deep Muddy
River 3 Creek 1 Muddy
Leek 2 Dam
Area Randleman
Lake
Year

Mean Phosphorus (Ppb)
853
82.7
79.1
78.9
78.0
83.9 101.6
95.1
95.4
953
953
102.7 322.0
360.9
287.7
278.1
232.9
232.7 162.0
166.4
1513
150.4
141.0
1443 74.9 92.7
73.2 88.4
74.2 85.7
74.8 86.0
76.6 84.9
79.1 90.0 42.0
40.8
41.9
423
43.8
46.0 48.8
46.4
49.4
50.3
53.9
56.0 90.8
91.7
86.9
86.7
84.7
87.3 1951
1967
1943
1953
1960
1975

Mean Chlo h -e (ppb)
243
24.4
233
23.2
22.4
23.1 26.9
27.7
24.9
243
213
21.0 783
813
75.6
74.7
69.2
68.6 29.7
30.2
28.8
28.7
273
27.2 17.7 26.4
17.7 26.1
17.4 25.2
17.4 25.2
17.1 24.4
17.2 24.9 12.6
125
123
12.6
12.6
12.9 14.0
13.7
14.0
14.1
143
143 21.4
213
20.9
20.9
203
203 1951
1967
1943
1953
1960
1975

Al I Nuisance Frequency %
12.7
123
10.9
10.7
9.6
103 16.3
17.7
13.2
12.3
8.4
7.9 813
83.1
79.7
79.1
75.1
74.6 20.9
21.9
193
19.2
17.0
16.9 43 15.6
43 15.0
4.1 13.7
4.1 13.6
3.8 12.4
3.9 13.1 1.1
1.0
1.0
1.0
1.0
1.2 1.7
13
1.7
1.7
1.9
2.0 10.3
10.4
9.7
9.7
9.0
9.1 1951
1967
1943
1953
1960
1975

Secchi Depth m
0.99
0.99
1.02
1.02
1.04
1.02 0.93
0.91
0.98
0.99
1.07
1.08 0.42
0.41
0.44
0.44
0.47
0.47 0.88
0.86
0.89
0.90
0.92
0.93 1.19 0.94
1.19 0.95
1.20 0.97
1.20 0.97
1.21 0.99
1?0 0.98 1.40
1.40
1.40
1.40
1.40
139 133
135
133
133
132
131 1.20
1?0
1.20
1.20
1.20
1.20 1951
1967
1943
1953
1960
1975

O xwen Depiction m m2-d
1,189
1,187

1,155
1,136
1.152 1,244
1,264

1,184
1,112
1,100
not calculated for individual subbasins 1,110
1,113
1,098
1,097
1,083
1,095 1951
1967
1943
1953
1960
1975

O xygen Depletion m mM
598
597
583
581
571
580 704
715
678
670
629
623
not calculated for individual subbasins 279
280
276
276
272
273 1951
1967
1943
1953
1960
1975
IV-35
Table IV-20
Comparison of Lake Water Quality
Lake Secchi
Depth
(m) Total
Phosphorus
(mg/L) Chlorophyll a
(mg/L) Area
(acres)
Badin Lake 1.1 0.03 23.5 5,350
Belews Lake 3.95 0.015 1 4,030
B. Everette Jordan Reservoir 0.5 0.08 26 14,300
Falls of the Neuse Reservoir 0.6 0.08 56 12,490
Harris Lake 1.8 0.03 24 4,150
Lake Hickory 1.55 0.035 22.5 4,100
Lake Rhodhiss 1.0 0.1 22 3,500
Lake Tom-A-Lex 0.8 0.045 26 650
Randleman Lake' 1.2 0.07 19.4 3,123
' Assume WWTP effluent concentration of TP is 0.5 mg/L.
Values derived from
"1988 North Carolina Lakes Monitoring Report,"
NCDEM Report No. 89-04,1988
N-36
E. References
I. M.N. Beaulac and K.H. Reckhow, "An Examination of Land Use-Nutrient
Export Relationships," Water Resources Bulletin, Volume 18, Number 6,
December, 1982, pp. 1013-1024.
2. USEPA Chesapeake Bay Program, "Monitoring Studies of Nonpoint Pollution
in Chesapeake Bay Test Watersheds: Final Completion Report," US
Environmental Protection Agency, Annapolis, Maryland, 1982.
3. USEPA, "Results of the Nationwide Urban Runoff Program: Volume I: Final
Report," US Environmental Protection Agency, Water Planning Division,
Washington, D.C., December 1983.
4. J.P. Hartigan, T. P. Quasebarth, and E. Southerland, "Calibration of NPS
Model Loading Factors," Journal of Environmental Engineering, Volume 109,
Number 6, December 1982, pp. 1259-1272.
5. A.S. Donigian and N. H. Crawford, "Modeling Nonpoint Pollution from the
Land Surface," EPA-60013-76-083, US Environmental Protection Agency,
Environmental Research Laboratory, Athens, Georgia, July 1976.
6. D.M. Griffin et al., "Analysis of Nonpoint Pollution. Export from Small
Catchments," Journal of Water Pollution Control Federation, Volume 52,
Number 4, April 1980, pp. 780-790.
7. T.J. Grizzard et al., "Assessing Runoff Pollution Loadings for 208 Planning
Programs," Presented at the ASCE National Environmental Engineering
Conference, Nashville Tennessee, July 13-15, 1977.
8. Camp, Dresser & McKee, Watershed Management Study: Oak Hollow and
City Lake Watersheds, City of High Point and Guilford County, December
1989.
IV-37
9. Northern Virginia Planning District Commission, Washington Metropolitan
Area Urban Runoff Demonstration Project, prepared for Metropolitan
Washington Council of Governments, Washington, D.C., April 1983.
10. Guilford County Planning and Development Department, Southwest Area Plan,
Comprehensive Plan Series, 1989.
11. "1983 Land Use Plan (Revised 1985) City of High Point, North Carolina,"
Prepared by High Point Department of Planning & Development.
12. Randleman Lake Watershed Critical Area Map, prepared by Randolph County.
13. USDA, "Deep River Erosion Study, North Carolina," Prepared by United
States Department of Agriculture, Soil Conservation Service, Forest Service,
May 1985.
14. USDA, "Soil Survey of Guilford County, North Carolina," United States
Department of Agriculture, Soil Conservation Service, December 1977.
15. "G.S. 162A-7 & 153A-285 Review Document and Environmental Impact
Statement, Randleman Lake, Randolph and Guilford Counties, North Carolina
(Draft)," Prepared by Piedmont Triad Regional Water Authority, January 1990.
16. W.W. Walker, Jr., 'Empirical . Methods for Predicting Eutrophication in
Impoundments; Report 4, Phase III: Applications Manual," Technical Report
E-81-9, US Army Engineer Waterways Experiment Station, Vicksburg,
Mississippi, July 1987.
17. W.W. Walker Jr., "Empirical Methods for Predicting Eutrophication in
Impoundments; Report 3, Phase III: Model Refinements," Technical Report
E-81-9, US Army Engineer Waterways Experiment Station, Vicksburg,
Mississippi, March 1985.
IV-38
18. W.W. Walker Jr., "Empirical Methods for Predicting Eutrophication in
Impoundments; Report 2, Phase II: Model Testing," Technical Report E-81-9,
US Army Engineer Waterways Experiment Station, Vicksburg, Mississippi,
September 1982.
19. W.W. Walker Jr., "Empirical Methods for Predicting Eutrophication in
Impoundments; Report 1, Phase I: Data Base Development," Technical Report
E-81-9, US Army Engineer Waterways Experiment Station, Vicksburg,
Mississippi, May 1981.
20. R. C. Dodd, J. F. Smith, and J.D. Vogt, "The Development of a Phosphorus
Management Strategy for Two Piedmont Reservoirs in North Carolina," Lake
and Reservoir Management, 4(2):243-252, 1988.
21. "1988 North Carolina Lakes Monitoring Report," NCDEM Report No. 89-04,
1988.
IV-39
V. Toxic Substances Evaluation
This chapter addresses the loadings of inorganic and organic pollutants to the
proposed reservoir. In-lake concentrations of these pollutants will depend on several
factors, including loadings from wastewater treatment plants and other point sources,
nonpoint sources, and the reservoir water balance. Since these properties vary both
seasonally and yearly and the processes involved in chemical transport in reservoirs
are quite complex, several simplifications were made in evaluating the system.
The approach used involves a simple mass balance model of the reservoir. First,
a review was made of all point sources of toxics in the watershed. This review was
used to establish the criteria for identifying the problem constituents to be modeled.
Mass loadings from each point source were then computed. These mass loadings
were entered into the model, which generated an average monthly lake concentration
for each pollutant for each month of data available from the flow analysis developed
in Section III. This assessment revealed the concentrations of toxics in the reservoir
if all the chemical was dissolved. This was considered a conservative estimate
because this approach ignores physical losses of the chemicals such as adsorption or
volatilization.
A. Survey of Existing Sources
This section is a discussion of the significant sources of toxic chemicals identified
in the Randleman Lake watershed. Several databases were analyzed to identify the
major sources of toxic chemicals in the watershed, including lists of National Point
Discharge Elimination System (NPDES) permit holders with the NCDEM,' ground-
water monitoring well data from wells near the Seaboard Chemical Company and the
High Point Landfill, and effluent water quality data from the City of High Point
Eastside WWTP.4 In addition, unpublished water quality data collected by the
USGSS at various points in and around High Point Lake and Oak Hollow Lake were
used to assess upstream water quality, and the U.S. Environmental Protection Agency
(EPA) Storet data6 for the Randleman Lake watershed since 1980 was reviewed.
Finally, a drive-through was made of the watershed to assess land use and point
source impacts on water quality. This review of existing data revealed several
important point sources which were incorporated into the model. Each point source
is discussed in more detail below.
V-1
1. High Point Eastside Wastewater Treatment Plant
High Point's Eastside wastewater treatment plant discharges treated wastewater
to Reddick's Creek about one mile upstream from the creek's confluence with the
Deep River. The location of the plant is indicated on Figure V-1. According to an
extensive water quality study conducted by NCDEM from 1983 to 1987, the plant was
a major contributor to water quality degradation in the Upper Deep River watershed.
Since 1987, the plant has undergone several process modifications to improve effluent
water quality. Nevertheless, the plant typically discharges approximately 10 mgd; this
volume is large enough that even low concentrations of toxics in the effluent may
have an adverse impact on Randleman Lake water quality. High Point Eastside
W VTP personnel maintain extensive records on the quality of raw and treated
wastewater. These data were used to estimate pollutant loadings from the plant into
Randleman Lake. Treated water is analyzed monthly for nitrates and nitrites,
phosphorus, and heavy metals. In addition, a scan for priority pollutants in the plant
effluent has been conducted yearly since 1988. Since the plant improvements were
completed within the last two years, only the data collected after January 1988 were
used to estimate lake loadings. Effluent quality data prior to this date do not reflect
the recent enhancements, which should improve treated water quality.
2. Other NPDES Permit Holders
The Randleman watershed receives 42 NPDES permitted discharges. The
majority of the permits cover discharges which should not affect the concentration of
toxic compounds in the lake. For instance, two of the permits cover rainwater dis-
charge from bermed areas around oil storage tanks, and three permits cover the
discharge of non-contact cooling water. There are 12 permitted wastewater dis-
charges from mobile home parks and subdivisions and several additional permits for
schools. Since non-contact cooling water should not contain toxic chemicals, and the
sum of all rainwater discharges from bermed areas is an insignificant fraction of the
total lake volume, these permitted discharges were not included.
The High Point Eastside WWTP is the major NPDES permit holder in the water-
shed, so it is handled separately in the model. The maximum flow from any of the
other permitted discharges is 100,000 gallons per day. In fact, the sum of all other
permitted discharges in the Randleman watershed totals less than 1 percent of the
amount discharged from the Eastside plant. Therefore, all wastewater discharges
located downstream from High Point Lake are summed under "Other NPDES Permit
V-2
KERNERSVILLE
rob `% ?_?? '?
1 %
%
?r
v
c ONEENSOORO
OAK NOL L"
LAKE ,fro
N16N POIMt
LAKE r4~
AN TOWN
HIGH POINT
LANDFILL a
sEAS0AR0
CHEMICAL COMPANY
EK
r ??cMJN NIGH POINT %
EASTSIDE WWTP
W?I=CONMTr Z
?»??M Etovrrr L
?, ANCNDALE ?y?o.
r •ESO?? %
?NOARt ,
%
%
LRANDLEMAN
LAKE
SCALE a SIMS N?GLF¦AN
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
LOCATIONS OF MODELED
POINT SOURCES OF TOXICS
LOCATIONS OF POINT SOURCES SHOWN
ARE APPROXIMATE
FIGURE X -I
Holders" in the model. The locations of the sources included in the model are shown
on Figure V-2.
Permitted discharges upstream from High Point Lake are not included in this
assessment. Their effect on Randleman Lake water quality should be governed by
the trapping of pollutants by Oak Hollow and High Point lakes. The water quality
data collected by the USGS in and around the two lakes in 1988 and 1989 indicate
that Oak Hollow and High Point lakes trap many of the pollutants, particularly
metals such as copper and chromium. Releases from the reservoirs contain relatively
constant concentrations of the toadcs modeled. Any effects on Randleman Lake are
included in the flow released at High Point Lake.
3. Seaboard Chemical Company
The Seaboard Chemical Company is a solvent recovery plant which ceased
operation in 1988. Its location in the watershed is shown on Figure V-1. The
company blended and processed spent organic solvents. Groundwater contamination
from the site was discovered downgradient from two evaporation ponds in 1983.
Since that time, several organic chemicals have been detected in some or all of the
monitoring wells around the site. In particular, significant quantities of methylene
chloride, tetrachloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethene, and toluene
have been detected in four or more of the monitoring wells.
Even though the plant is no longer operating and the evaporation ponds have
been closed, groundwater contamination has not been removed. These solvents may
affect lake water quality because the plant is very near the proposed water boundary.
The chemicals should migrate in the same direction as the. groundwater, towards the
Deep River. The evaporation ponds, the apparent source of groundwater
contamination, are within approximately 1,000 feet of the reservoir normal pool
elevation and significant quantities of the organic contaminants listed above have
been measured in wells much closer to the river.
V-3
[ERNEMI LL E
p obt W? owl
ow
`?
, ~1
II ``
?z
%
I
4 o GREENUM
J
M
e
?wKr
OAK /IOLLOI %#
LAKE ` ?r0
NICK POW
LAKE ?? •??
,? Mr N
% lvw
k do
MN PMT ?.
' is
? `
for
A?IIOALE ? /
``%
1 r,?orc?Ep ;,?. _ ?
1 . 1 a 1
K"Ll IM "ILK/
LOCATNONS OF POINT SOURCES SHMN
AK APPROXIMATE
.Yr
RA/OLEVAN
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
LOCATIONS OF
"OTHER NPDES PERMITTED DISCHARGES"
FIGURE X-2
4. Clay of High Point Landfill
The High Point municipal landfill is located adjacent to the Seaboard Chemical
plant site and surrounds it on two sides. Its location in the watershed is shown on
Figure V-1. In fact, there is some question as to the contribution of the landfill to
the contamination detected in the Seaboard monitoring wells. Portions of the landfill
border the Deep River and most of these sections are older and unlined. There are
several monitoring wells around the landfill. Water quality data from these
monitoring wells is available for 1987, 1988, and 1989. In addition, water quality data
on the Deep River adjacent to the landfill is available for the mid-1970s and for 1987.
This data suggests that certain contaminants leach from the landfill into the river.
It was earlier thought that the landfill may have a greater effect on Randleman Lake
water quality than the chemical company because it is larger and closer to the river.
Also, because portions of the landfill abut the Deep River, it was suggested that the
reservoir may actually cover some of the older parts of the landfill. However, recent
field surveys by T&R Associates have proven this not to be the case.
5. Surface Water Inflows
The majority of water that enters the lake would be surface water from the Deep
River and other tributaries. Data from the flow analysis in Section III was used to
estimate the total volume of all surface water flows into the reservoir. These flows
include the Deep River upstream from the reservoir, all tributaries of the Deep
River, and any overland flow from precipitation.
Water quality data on the concentrations of toldcs in surface water inflows to the
proposed reservoir are scarce. The unpublished USGS data for High Point and Oak
Hollow lakes includes one sampling point downstream from both lakes for baseflow
water quality; however, data for stormwater quality were not available at these
stations. Concentrations of some of the metals in stormwater runoff may be relatively
high compared to baseflow concentrations. Therefore the loadings to Randleman
Lake based on the observed baseflow concentrations may be somewhat low compared
to the loadings from stormwater runoff.
11130190 V-4
REP166A -B
B. Identification of Problem Constituents
1. General
While several point sources were identified, much of the pollutants discharged
from the individual sources would have a negligible effect on water quality in
Randleman Lake. The pollutants would be diluted to concentrations much lower
than the detection limit. Determining which pollutants may have adverse impact on
water quality is difficult. Choosing the pollutants to be modeled requires establishing
criteria to judge a pollutant's potential impact.
The U.S. Environmental Protection Agency gathers water quality data throughout
the United States and stores them in a central file for access by the general public.
The EPA Storet data for the Randleman Lake watershed were reviewed to determine
which pollutants were consistently detected in the Deep River over the last ten years.
Of those detected, several were chosen for modeling based on both their presence
in the watershed and their potential toxicity. These pollutants include aluminum,
copper, cadmium, chromium, lead, nickel, zinc, iron, and nitrates. Some of these
chemicals do not occur in very large quantities, but were modeled because of their
potentially severe impact on drinking water supplies. For instance, although high
nitrate concentrations were limited to the streams close to the High Point WWTP,
they were modeled because of their toxic effect on infants even at low concentrations.
Five organic chemicals are also of concern, including methylene chloride, 1,1,2,2-
tetrachloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethene, and toluene. These
were chosen because they were detected in at least four of the six Seaboard Chemical
Company monitoring wells, suggesting widespread contamination. The chemical
company site is of concern because of its proximity to the reservoir. These chemicals
were modeled because of their toxic and carcinogenic nature and because they are
indicators of the impact of the Seaboard site on the reservoir.
2. City of High Point Eastside Wastewater Treatment Plant
A summary of concentrations of those inorganic pollutants in the City of High
Point Eastside WWTP effluent which were considered important is presented in
Table V-1. The concentrations shown in the table are the means of all
concentrations measured in the plant effluent since 1988. Scans of priority pollutants
revealed no significant quantities of organic compounds; however, copper, nickel,
zinc, lead, and aluminum have been measured in significant concentrations. Nitrate
V-5
concentrations were included because of their potentially deleterious impact on the
reservoir as a drinking water supply.
Table V-1
High Point Eastside WWTP Average Effluent Co ncentrations.
Constituent Average Yearly Concentration (mg/L)
1988 1989 2-yr. average
nitrate/nitrite N.D. 7.73 7.73
Al (aluminum) N.D. 0.218 0.218
Cd (cadmium) 0.002 0.0005 0.001
Cr (chromium) 0.017 0.022 0.019
Cu (copper) 0.041 0.054 0.048
Fe (iron) N.D. 0.183 0.183
Pb (lead) N.D. 0.009 0.009
Ni (nickel) 0.057 0.027 0.042
SO4 (sulfates) N.D. N.D. 20.0*
Zn (zinc) 0.126 0.106 0.116
N.D. = no data available; used one year average.
* = no data available; assumed conservative value.
3. Other NPDES Permitted Discharges
No data are available for metals and organic concentrations in any of the other
NPDES discharges. Since the discharges are mostly from small generators of
municipal wastewater, the wastewater quality was assumed to be identical to the
Eastside WWTP effluent. While this is a reasonable assumption for nitrate-nitrogen,
it is probably conservative for heavy metals. Since the small WWTPs probably do not
receive appreciable quantities of industrial wastewater, it is unlikely that the influent
contains heavy metals in concentrations as high as in the High Point WW TP influent.
V-6
4. Seaboard Chemical Company
Law Engineering Corporation conducted extensive hydraulic conductivity tests at
the site. These data, along with groundwater elevations measured during sampling,
were used to determine groundwater flow from the site into the reservoir.
Groundwater flow is based on Darcy's Law, which states:
Q = dh/dl (K) (A)
where Q = groundwater flow (L3/T)
dh/dl = hydraulic gradient (L/L)
K = hydraulic conductivity (L/T)
A = area (L2)
The hydraulic gradient at the site was determined to be approximately 0.04 ft/ft. Law
Engineering Corporation measured an average hydraulic conductivity of 1.5 x 104 feet
per minute (fpm). The contaminant plume was assumed to be 350 feet wide and the
aquifer depth was assumed to be 20 feet. These values are equivalent to a ground-
water flow from the contaminated portion of the aquifer to the reservoir of approxi-
mately 450 pd.
Concentrations of the groundwater were estimated from on the available moni-
toring well data. Concentrations of each chemical in the chosen monitoring wells
were compared during a five year period. Monitoring wells 3, 5, and 6 were chosen
because they He in a relatively straight line along the direction of groundwater flow
between the evaporation pond, the apparent source of the organic contamination,
and the river. Organic chemical concentrations in well 6, which is next to the pond,
continued to increase as recently as July 1989; on the other hand, the organic
chemical concentrations in well 3 were lower in 1989 than in 1987.
The highest measured concentration of all the organic chemicals studied in well
3 was used as the concentration of chemical in the groundwater entering the lake.
This estimate was considered reasonable and conservative because these concentra-
tions reflect natural physical processes, such as dispersion and retardation, which will
decrease the mass of chemical leaching into the reservoir. In addition, these
concentrations do not include any effects from remedial cleanup that may occur at
the site. The input concentrations of the five organic chemicals modeled are
presented in Table V-2.
V-7
Table V-2
Concentration of Chemical Contaminants from
Seaboard Chemical Co.
Constituent Concentration
Methylene chloride 2.6 mg/L
1,1,2,2-Tetrachloroethene 3.8 mg/L
1,1,1-Trichloroethane 23. mg/L
1,1,2-Trichloroethane 0.8 mg/L
Toluene 6.2 mg/L
5. City of High Point Landfill
The effect of the landfill on reservoir water quality is difficult to predict.
Groundwater monitoring well data are available from the mid-1970s, 1987, and 1988
only. Although the NCDEM measured the hydraulic gradient across the landfill,
there are no data available on hydraulic conductivity. Thus, it is very difficult to
estimate the movement of groundwater through the landfill.
Since the landfill surrounds the chemical company site, the hydraulic conductivity
used for the landfill was assumed to be identical to that measured at the chemical
company. The total volume of flow from the site was then calculated in the same
manner as used for the Seaboard Chemical site. The calculated volume, based on
the length of the landfill adjoining the river, is approximately 1,800 gpd. The
averages of the chemical concentrations measured in the wells bordering the Deep
River were used as the input concentrations in the model. These concentrations are
shown in Table V-3. Only the data from 1987 and 1988 were used because these
values were generally higher than those from the mid-1970s.
6. Surface Water Inflows
Surface water quality data were obtained from two sources. Both the
unpublished data from the USGS and EPA's water quality data for the Randleman
Lake watershed were used to estimate the concentrations of pollutants in the surface
waters entering Randleman Lake. The USGS data focused on water quality in and
around High Point and Oak Hollow lakes, but included one sampling point down-
V-8
stream from the lakes. EPA Storet data from sampling points throughout the
Randleman Lake watershed since 1980 was also reviewed.
Table V-3
Concentrations of Chemical Contaminants from
the High Point Landfill.
Constituent Concentration
Fe (Iron) 0.008 mg/L
N03-N (Nitrate) 2.0 mg/L
S04 (Sulfate) 30. mg/L
Zn (Zinc) 0.0056 mg/L
Cu (Copper) 0.0002 mg/L
Most of the pollutants measured and included in the EPA Storet database are
below the detection limit, particularly in the upper reaches of the watershed. Down-
stream from the High Point Eastside W V P, detectable levels of some pollutants,
such as copper, zinc, and nickel, are more common. However, it is difficult to
separate the WWTP discharges from background levels of the pollutants in the river.
In addition, the detection level varies between sampling dates, making it difficult to
determine an "average" background concentration. Thus, the EPA Storet data was
not used to estimate surface water inflow concentrations; instead, the data assisted
in judging whether a particular pollutant's concentration was significant enough to
model.
The data collected by the USGS were used to estimate surface water inflow con-
centrations of the modeled pollutants. The detection limits used by the USGS are
generally lower than those found in the EPA data. The surface water inflow con-
centrations are shown in Table V-4. The concentration corresponding to the detec-
tion limit was used when the measured value was reported to be less than the
detection limit. While this approach ignores the impact of storm flows, when
pollutant concentrations might be much higher, this is required by the lack of water
quality data available for storm flow. On the other hand, base flow concentrations
of several of these pollutants probably range well below the detection limit.
V-9
Table V-4
Concentrations of Chemical Contaminants in Surface Water
Inflows to Randleman Lake
Al (Aluminum) 0.5 mg/L
Cd (Cadmium) *0.001 mg/L
Cr (Chromium) **0.002 mg/L
Cu (Copper) 0.004 mg/L
Fe (Iron) 0.250 mg/L
Pb (Lead) *0.0035 mg/L
Ni (Nickel) 0.0025 mg/L
Zn (Zinc) *0.010 mg/L
S04 (Sulfates) 0.0093 mg/L
N03 (Nitrates) 0.200 mg/L
* At least one measurement was below the detection limit.
** All measurements were below the detection limit.
C. Development of Toxic Substances Model
Once sources of potentially toxic substances were identified and the loadings
established, a toxic substances model was used to estimate average lake concentra-
tions for each month of water balance data. The model generates the average con-
centration of chemical in the lake for each month. The average annual lake
concentrations were calculated for each year and these were compiled into a
cumulative frequency distribution for chemicals which, in the High Point W Y7P flow,
had a significant impact on the mean annual concentration in the reservoir.
The toxdcs model is a mass balance of Randleman Lake based on existing
chemical loadings and the reservoir hydraulic inputs and outputs generated by the
yield model developed in Section III. The total mass of chemical input from the
principal sources--the wastewater treatment plant, the chemical company, the landfill,
and upstream flow--is calculated by multiplying the monthly flow volume from each
source by its assumed concentration. Pollutant input from each source is summed
V-10
to determine the total mass of chemical input into the lake during any month,
according to the following equation:
M; = M„+M,+MC+M,
where
M; = mass of chemical input into reservoir
M„ = mass of chemical input from upstream
Mw = mass of chemical input from WWTP
Mc = mass of chemical input from chemical company
M, = mass of chemical input from the landfill
The flow volumes from the WWTP, the chemical company, and the landfill were
assumed constant for the evaluation period. Upstream input to the reservoir was the
only variable flow volume. Concentrations of chemicals from all sources remained
constant.
The monthly mass of chemical released from the reservoir was calculated by
multiplying the releases, including the required downstream releases, and any excess
from the spillway, and the water treatment plant removals calculated in Section III,
by the in-lake concentration determined from the previous month. The following
equation describes the calculation of monthly chemical releases from the reservoir:
M0 = (MS + MP + M') x C;.1
where
MO = mass of chemical removed from reservoir
Mg = mass of chemical removed from excess spills
MP = mass of chemical removed through pumpage to water
treatment plant
Mr = mass of chemical removed from required releases
C;_1 = reservoir concentration from previous month
The difference between the inputs and outputs is the change in the total mass of
chemical in the reservoir for the month. The change in mass is then added to the
mass of chemical in the reservoir during the previous month and the sum is divided
V-11
by the volume of the reservoir during the month to determine the reservoir
concentration.
C; = [(M; - Mo) + (Vi-1 * Ci_1)J/ V;
where
C; = reservoir concentration for month
V;-1 = reservoir volume from previous month
V; = reservoir volume for month
The model repeats this calculation for the nearly 60 years of flow data. The mean
annual concentration and range of mean annual concentrations were then determined
for each chemical. These are presented in the results section with the cumulative
frequency distributions for selected chemicals. These distributions are presented on
graphs of average annual concentration versus the percentage of years for which the
concentration is less than a given value. This allows an assessment of typical annual
concentrations and gives an idea of possible concentrations during extreme years.
Although the model computes the concentrations monthly, mean average
concentrations were considered more appropriate for presenting results, primarily
because it is unrealistic to assume that monthly mass loadings will be completely
mixed throughout the reservoir on a monthly basis.
D. Model Results
1. Mean Concentrations
Mean annual lake concentrations were calculated for nine inorganic and five
organic pollutants. The overall mean of 58 years of mean annual lake concentrations
with and without the wastewater treatment plant flow are presented below in
Table V-5. The NCDEM criteria for Class II waters' and the Maximum Contaminant
Limit (MCL) as defined by the 1986 Amendments to the Safe Drinking Water Act
(SDWA)8 are presented for comparison.
None of the calculated mean concentrations, except for copper, are greater than
the NCDEM criterion established for the pollutant with or without the wastewater
treatment plant. The NCDEM criterion for copper is 7 micrograms per liter (ug/L)
and the estimated mean annual concentration in the lake is slightly higher at 9.5 ug/L
with the WWTP flow. The wastewater treatment plant clearly has an impact on
V-12
water quality by increasing the concentrations of chromium, copper, lead, nickel, zinc,
nitrates and sulfates.
None of the calculated mean concentrations, except aluminum, exceed the
SDWA MCL criteria. Aluminum has a secondary MCI, which indicates a concern
related to cosmetic and aesthetic effects of this substance. Health related effects are
covered by the primary MCU. Excessive concentrations of aluminum in treated
water can precipitate and cause problems in the water distribution system.
Table V-5
Comparison of Mean Annual Concentrations of Pollutants
with State and Federal Water Standards
Mean Annual Concentration NCDEM

Constituent
With WWTP
Without WWTP Criteria for
Class II Water MCL From 1986
Amendments to SDWA
Al (mg/L) 0.46 0.49 N.S. 0.05
Cd (ug/1-) 1.01 0.98 2.0 5
Cr (ug/L) 4.12 1.96 50 100
Cu OWL.) 9.46 3.92 7 1300
Pb (ug/L) 4.15 3.43 25 5
Ni (ug/L) 7.42 246 25 N.S
Zn (ug/I-) 23.2 9.82 50 50002
Fe (mg/L) 0.24 0.25 1.0 032
NO3 (u91L) 1.68 0.82 10.0 10
SO4 (ug/L) 253 0.01 250 N.S.
Methylene Chloride (ug/L) 0.0049 0.172 N.S.
1,1,2,2-Tetrachloroethane (ug/L) 0.03 N.S. N.S.
1,1,1-Trichloroethane (ug/L) 0.03 3.08 200
Toluene (ug/L) 0.008 11 2000
N.S. - No Criterion or MCL
2 - Secondary MCL
These estimates are most likely higher than the actual concentrations in the
reservoir because the model accounts for the removal of a pollutant from the reser-
voir only through the spillway, the required releases, and water treatment plant
pumpage. The model does not account for potential losses as a result of natural
chemical or physical processes, such as partitioning with sediment, hydrolysis, or
volatilization. These losses can be quite large. Several investigators have measured
V-13
pollutant concentrations of heavy metals in both the sediment and the water phase
of different lakes and found that these chemicals tend to partition in the sediment
phase."' The EPA Storet data indicates that most of the pollutants present in the
Deep River partition into the sediment phase. Therefore, the values generated by
the model should be viewed as higher that the expected concentrations.
2. Ranges of ConcentratIons
The range of mean annual concentrations calculated by the model with and with-
out the wastewater treatment plant flow discharged into the lake is presented in
Table V-6. For most of the pollutants, the maximum concentrations are those expec-
ted during relatively dry periods when inflow and reservoir volume would be low. For
Table V-6
Range of Mean Annual Concentrations of Pollutants Calculate d by the
Toxics Loading Model With and Without WWTP flow.
With Wastewater Treatment Without Wastewater
Constituent Plant Flow Treatment Plant Flow
minimum maximum minimum maximum
Al (ug/L) 0.43 0.47 0.48 0.51
Cd (ug/L) 0.97 1.06 0.95 1.02
Cr (ug/L) 2.93 6.45 1.72 2.03
Cu (ug/L) 6.40 15.2 3.81 4.05
Pb (ug/L) 3.69 4.96 3.33 3.55
Ni (ug/L) 4.71 12.7 2.38 2.53
Zn (ug/L) 15.8 37.2 9.52 10.1
Fe (mg/L) 0.24 0.25 0.24 0.24
N03 (mg/L) 1.21 2.60 0.81 0.85
S04 (mg/L) 0.009 0.011 1.17 5.13
Orranic Constituents
Methylene Chloride (ug/L) 0.0005 0.017
1,1,2,2-Tetrachloroethane (ug/L) 0.0008 0.0246
1,1,1-Trichloroethane (ug/L) 0.005 0.15
1,1,2-trichloroethene (ug/L) 0.001 0.0052
Toluene (ug/L) 0.0013 0.0401
V-14
example, the maximum chromium concentration with and without the WWTP flow
occurs during the critical drought periods of 1967. During 1966 and 1967, the WWTP
flows were relatively high compared to the lake inflows, resulting in less dilution of
the high chromium concentration in the WWTP effluent. This, in combination with
the low reservoir volumes, resulted in the highest calculated concentrations in the
reservoir. Without the WWTP, the highest concentrations also occurred during 1966
and 1967 because of the high net evaporation during those years.
The distributions of the heavy metals and other pollutants whose maximum
annual concentrations would be significantly greater with the WWTP flow than
without it are shown on Figures V-3 through V-7. Sulfates were not graphed
because, even with the WWTP flow, the concentrations in the reservoir would be
insignificant.
Each figure indicates contains the distribution of mean annual concentrations
with and without the wastewater treatment plant flow. These distributions demon-
strate the importance of the upstream concentration in modeling reservoir concentra-
tions. Average annual reservoir concentrations for all pollutants are very near the
concentration of the surface water entering the reservoir from upstream when the
concentration is modeled without the WWTP flow.
For aluminum and iron, the assumed upstream concentrations are greater than
the concentrations in the WWTP effluent; therefore, the reservoir concentrations
without the WWTP would be lower than with the WWTP.
Mean annual reservoir concentrations with the WWTP flow would be
approximately equal to the flow-weighted average concentration of all the reservoir
inflows. However, Figures V-3 through V-7 demonstrate that for some pollutants, the
WWTP discharge would affect the distribution of reservoir concentrations during
drought conditions. The low flows combine with the low reservoir volume to produce
high concentrations of these pollutants. While the results indicate that the maximum
annual concentration may be twice the mean annual concentration, only the
maximum value of copper exceeded its NCDEM limit.
The maximum value for lead was approximately equal to the SDWA criterion of
5 ug/I, which is applicable to the treated water. If the lead is largely insoluble,
conventional water treatment should reduce the lead concentration to a safe level.
Another possibility is that significant quantities of lead and other insoluble metals
could be removed at the WWTP if chemical addition is used to remove phosphorus.
For example, chemical phosphorus removal could achieve up to a 50 percent
reduction of copper and lead. These removal levels would result in approximately
V-15
0.007
Moon Annual Cr Conc. with WWTP Flow
0.006
J
P
E o.005
U
c
O
0 0.004
c
•
u
C
0
U 0.003
C
0
0.002
0.CC -t
0
0.007
0.006
J
a'
D+
E 0.005
U
C
0
0 0.004
c
•
C
0
U 0.003
c
0
•
0.002
0.001 -+
0
20 40 60 s0 100
X of moon Annual Concentrations < C
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
DISTRIBUTION OF
CHROMIUM CONCENTRATIONS
IN RANDLEMAN LAKE
20 40 661 b0; 1p0
7L of Moon Annual Concentrations < C
Moon Annual Cr Conc. without WWTP Flow
FIGURE Y-3
J
O?
E
U
C
0
0
c
u
C
O
U
C
0
3
J
P
E
v
0
0
V
C
0
U
c
0
•
Mean Annual Cu Conc. with WWTP Flow
0.015
0.014
0.013
0.012
0.011
0.010
0.009
0.008
0.007
0.006
0.005
0.004
0.003
0.002
80 100
0 20 40 60
X of Mean Annual Concentrations < C
Mean Annual Cu Conc. without WWTP Flow
0.015
0.014
0.013
0.012
0.011
0.010
0.009
0.008
0.007
0.006
0.005
0.004
0.003
0.002
0 20 40 60 BO 100
S of Mean Annual Concentrations < C
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
DISTRIBUTION OF
COPPER CONCENTRATIONS
IN RANDLEMAN LAKE
FIGURE V-4
Mean Annual Ni Conc. with WWTP Flow
0.016
0.015
0.014
0.013
J
a
012
0
.
E
,. 0.011
U
i 0.010
0
0 0.009
c
0.008
c
U 0.007
c
0 0.006

I
0.005
0.004
0.003
0.002
0 20 40 60 80 100
X of Mean Annual Concentrations < C
Mean Annual Ni Cont. without WWTP Flow
0.016
0.015
0.014
0.013
J
a 0.012
E
0.011
U
0.010
0
a 0.009
C
0 0.008
C
U 0.007
c
0 0.006

I
0.005
0.004
0.003
0.002
0 20 40 60 00 100
X of Moon Annual Concentrotions < C.
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
DISTRIBUTION OF
NICKEL CONCENTRATIONS
IN RANDLEMAN LAKE
FIGURE Y-S

2.6 Mean Annual N03 Concs. with WWTP Flow
2.5
2.4
2.3
2.2
J
N, 2.1
E 2.0
v 1.9
U 1.8
0 1.7
0 1.6
c
• 1.5
c 1.4
U 1.3
c
0 1.2
•
1.1
1.0
0.9
0.8
0.7
0.6
0 20 40 60 so 100
S of Mean Annual Concentrations < C
Moon Annual N03 Cont. without WWTP Flow
2.6
2.5
2.4
2.3
2.2
J 2.1
E 2.0
.. 1.9
u 1.8
c 1.7
0 1.6
c
e 1.5
C 1.4
v 1.3
c
0
1.2
•
1.1
1.0
0.9
0.8
0.7
7
0.6 4
0 20 40 60 80 100
% of Moon Annual Concentrations < C
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
DISTRIBUTION OF
NITRATE CONCENTRATIONS
IN RANDLEMAN LAKE
FIGURE Y-6
1 1,
Mean Annual Zn Cont. with WWTP Flow
0.040
0.038
0.036
0.031
0.032

E 0.030
U 0.028
c 0.026

a 0.024
0.022
0 0.020
U
C 0.018

0.016
0.014
0.012
0.010
0.008
0 20 40 60 80 100
x of Mean Annual Concentrations < C
Mean Annual Zn Conc. without WWTP Flow
0.040
0.038
0.036
0.034
J 0.032

E
v 0.030
u 0.028
0 0.026

S 0.024
e 0.022

0 0.020
U
C 0.018

i 0.016
0.014
0.012
0.010
0.008
0 20 40 60 80 100
X or Mean Annual Concentrations < C
PIEDMONT TRIAD REGIONAL WATER AUTHORITY
DISTRIBUTION OF
ZINC CONCENTRATIONS
IN RANDLEMAN LAKE
FIGURE V-7

50 percent reduction in mean copper concentrations and 15 percent reduction of lead
concentrations in the reservoir.
3. Comparison to High Point Lake and Oak Hollow Lake Water Quality
One way to evaluate the toxic substances model is by comparing the results to
the values measured in High Point Lake and Oak Hollow Lake by the USGS. This
comparison is presented in Table V-7.
Table V-7
Comparison of Mean Annual Pollutant Concentration to Meah
Concentration in Oak Hollow and High Point Lakes.
Randleman Lake
Constituent with
WWTP without
WWTP Oak Hollow Lake High Point Lake
Al (mg/L) 0.46 0.49 0.22 0.17
Cr (ug/L) 4.12 1.96 < 1 < 1
Cu (ug/L) 9.46 3.92 1 2
Fe (mg/L) 0.24 0.25 0.41 0.49
Pb (ug/L) 4.15 3.43 < 5 < 5
Zn (ug/L) 23.2 9.82 < 10 < 10
N03 (ug/L) 1.7 0.82 1.0 0.8
While concentrations of aluminum, chromium, copper, and zinc with the WWTP
flow are predicted to be higher than those measured in the two upstream lakes, the
predicted values are of the same order of magnitude as those found in the two lakes.
On the other hand, the concentrations calculated without the WWITP are comparable
to those measured in the two lakes. Since concentrations of chromium, copper, and
zinc are relatively high in the High Point WWTP effluent, it is expected that the
concentrations of these pollutants would be higher in Randleman Lake than in the
upstream reservoirs because they do not receive significant WWTP loadings.
However, the predicted values do not include any of the effects of sedimentation or
hydrolysis, which should reduce the concentration of the pollutants in the water
phase.
V-16
E. References
1. NCDEM Memorandum from M. L. Toler-McCullen to Miniature Subbasin Files.
Subbasin 03-06-08, July 1, 1989.
2. Seaboard Chemical Company, Groundwater Monitoring Analysis Reports, 1983-
1989, Solid and Hazardous Waste Management Branch, Environmental Health
Section, N.C. Dept. of Environment, Health and Natural Resources.
3. Annual Groundwater Sampling Laboratory Reports for Riverdale LandfiI4 Permit
No. 41-01, 1987-1988, Solid and Hazardous Waste Management Branch,
Environmental Health Section, N. C. Dept. of Environment, Health and Natural
Resources.
4. City of High Point Eastside Wastewater Treatment Plant Effluent Water Quality
Data, 1988-1989, NPDES Permit No. 0024210, High Point, North Carolina.
5. Preliminary Data in the High Point Lake Watershed, Guilford County, North
Carolina, provided by U. S. Department of Interior-Geological Survey.
Washington, D.C., 1989.
6. U. S. Environmental Protection Agency Storet System. Basin 03-06-08 Data from
1-8-80 through 1-1-90, Access Agency Code 21NC01WQ.
7. State of North Carolina. Department of Environment, Health and Natural
Resources, Division of Environmental Management, Administrative Code Section
15B NCAC 2B.0200 - Classification and Water Quality Standards Applicable to
Surface Waters of North Carolina, January 1, 1990.
8. USEPA 1987. National Primary Drinking Water Regulations - Synthetic Organic
Chemicals; Monitoring for Unregulated Contaminants - Final Rule, CFR 52
(130): 25689-25717.
9. J. P. Harding and B.A. Whitton. "Zinc, Cadmium and Lead in Water, Sediments
and Submerged Plants of the Derwent Reservoir, Northern England," Water
Research, Volume 12, pp. 307-316, 1978.
V-17
10. F. W. Pita and N. J. Hyne. '"I'he Depositional Environment of Zinc, Lead and
Cadmium in Reservoir Sediments," Water Research, Volume 9, pp. 701-706, 1975.
V-18

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FIGURE III - 3
Figures III-3, 4, and 5 present the flow duration curves for the three analyses at
the Ramseur USGS gaging station and Figures III-6, 7, and 8 present the flow
duration curves at the Carbonton Dam site. The curves plotted represent "best-fit"
curves for the data. Therefore, the lines drawn do not necessarily represent a point
to point plot of the data. The analyses at the two locations show the same general
trends - Randleman Lake has a positive effect on the critical lower flow conditions
in the Deep River for average monthly and average September analyses. This occurs
for flows up to the point where the curves cross. For example, for the average
monthly flow analyses at Ramseur, without Randleman Lake, there is a 2.5 percent
chance, on the average, that the flows will be less than 50 cfs. However, with
Randleman Lake, there is only an 0.5 percent chance, on the average, that the flows
will be less than 50 cfs. This trend is not apparent for the average annual analyses.
This is because on an annual basis, the difference in the two curves approximates the
yield from the reservoir. Also, for the average monthly and average September
analyses, the increased low flows due to the lake, on a monthly basis, reflect the lake
supplementing the base condition low flows with the minimum required releases.
WP 11/30/90 III-17
REP 16BAEB
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FIGURE III - 5

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FIGURE III - 8
E. References
1. F. E. Dendy and W. A. Champion, "SEDIMENT DEPOSITION IN U.S. RESERVOIRS -
Summary of Data Reported Through 1975." Miscellaneous Publication No. 1362, U.S.
Department of Agriculture, USDA Sedimentation Laboratory, Agricultural Research
Service, Oxford, Mississippi.
2. USDA, "SCS National Engineering Handbook, Section 3, Sedimentation," United States
Department of Agriculture, Soil Conservation Service, April 1971.
3. U.S. Army Corps of Engineers, Design Memorandum #5, Randleman Lake, "Phase II
Project Design," December 1982.
4. USGS Watstore System. Flow Data for gages 02098500, 02099000, 02099500, and
02100500.
5. National Oceanic and Atmospheric Administration, "Climatological Data - North Carolina."
National Climatic Data Center, Asheville, North Carolina.
WP11R9/90 III-18
REP168AEB
V`
nii y r DRAFT
WETLAND MITIGATION PLAN
14yo. 15 k For
RANDLEMAN LAKE
RANDOLPH AND GUILFORD COQ NTIES-,
V(eca
Cq?
CAROLI A
L
PREPARED OR
PIEDMONT TRIAD REGIONAL TER
>0
AUTHORITY
Koger Center, Wilmington Building, Suite 1 0
2216 West Meadowview Road
Greensboro NC 27407-3480
PREPARED BY
TRIANGLE WETLAND CONSULTANTS, INC.
Post Office Box 33604
Raleigh, NC 27636
July 10, 1995
Table of Contents
List of Figures ...............
..........................................
...
List of Tables ..
.......................
.......................................................
Executive Summa .......
.................
1.O Introduction ............... . ...........................................
1
.

...........................
1.1 Background ...................
...............
.
....................
1.2 Purpose and Objectives
.........................................
..........
2.0 Site Conditions .....
......
.................

....................................
2.1 Location and Attrib
t .................
3
u
es ........................
2.2 Habitat Types ......
....3
...........................
3
............................
............
2.3 Hydrogeomorphic T ............
...................................
ypes .................

...........
2.3.1 Spring/Seep Wetland Type ... ......................
5
...................................................
........
.........
2.3.2 Alluvial Fringe Wetland Type---
ype .
........................................................6
..........
2.3.3 Alluvial Backswamp Wetland Type ........................................................7
...........
2.4 Exceptional Habitat Area .....................................•..
s.................
...........
3.0 Potential Impacts .......... ..........
.........................................
11
......

4.0 Mitigation
.........
....
.........

4.1 Avoidance and Minimization Issues ...
................................ 12
.......•....""""'••"""
.........
....
4.2 On-Site Mitigation ...........................................
14
.... .
..........
4.2.1 Wetlands Creation and Habitat Restorati ..........
14
on
4.2.1.1 Existing Fields and Pastures.. ................
4.2.1.2 Littoral B
tt ............... .•, , , ,.•. ...........................::
15
o
omland Hardwood Wetlands .
4.2.1.3 Wet Flat Wo
dl ............ "" "" 15
o
ands .................................
4.2.1.4 Upland Ha
d 16
r
wood Forest Restoration ......
4.2.1.5 Site Preparati
P • "" ""' "" 18
on
rescriptions ....................
4.2.1.6 Reforestation A 18
............................
reas
4.2.2 Buffer Area Pre ...........
18
servation .................
4.2.3 Wildlife Enhan ............20
cement............

4.2.4 Fisheries Resource Enhancem ....
5
26
ent.......
4.3 Management Criteria for Buffer Are
....
"•
a
5.0 Monitoring

5.1 Ground Water ..........27
.......
.................
.................................
2 Soils ...............................28
............

...........................................
.....................
5.3 Vegetation .........

.
............................29
................
..
....................
5.4 Observation ..
.............................29
........
.................................
6.0 Regulatory Release 30
.........
..............................................
6.1 Contingency Plan 30
........................
.........................
7.0 References
...........................
.....................
Appendix .... .........31
..............

List of Figures
Figure 1 - Location of Randleman Lake .................................................................................4
List of Tables
Table 1 - Wetland Types Grouped According to a Hydrogeomorphic Classification....... 7
Table 3 - Tree and Shrub Species Recommended for Mitigation Planting in the
Bottomland Hardwood (BLH), Wet Flat Woodland (WFW), and Upland Zone
(U) at Randleman Reservoir ..........................................................................17
Table 2 - Summary of Restorable Fields and Pastures in 200 foot Buffer Zone at
Randleman Lake ...........................................................................................20
t EXECUTIVE SUMMARY
The Piedmont Triad Regional Water Authority ( PTRWA) has applied for a permit to
impact 119.11 acres of wetlands and inundate and additional 194.85 acres of stream channels
for the construction of a proposed water supply reservoir on the Deep River and Muddy
Creek. The project has been through the public interest review, and a consensus has been
reached with regard to the water dependent nature of the project and the lack of feasible
alternative sites. Therefore, mitigation, as presented in this document, is proposed to
compensate for the unavoidable conversion of approximately 119 acres of wetlands associated
with the construction of the Randleman Reservoir.
The wetland and aquatic habitats within the proposed reservoir were delineated and a
qualitative assessment and characterization were performed (see wetland maps (Poteat 1993).
In addition, biological assessment maps and report was submitted(Carter 1993)). The project
area contains a combination of aquatic and wetland habitats including, river stream channel
(245.34 ac), Piedmont alluvial forest wetlands (102 ac), bottomland hardwood forest wetlands
(4 ac), and wetland seeps (13 ac). The potential impacts resulting from the conversion of a
revised estimate of 314 acres of aquatic and wetland habitats to an open water aquatic habitat
have been identified in earlier reports (PTRWA 1990, 1994).
This mitigation plan includes on-site and off-site mitigation and is comprised of
wetland creation, restoration, and preservation, and fish and wildlife habitat enhancement.
Wetland mitigation will consist of creating approximately 107 acres of jurisdictional littoral.
zone bottomland hardwood wetlands (683 to 685 ft MSL) from existing fields and pastures.
Additionally, 132 acres of forested wet flat woodland adjacent to the proposed reservoir (685 -
to 690 ft MSL) will be established from open fields and pastures with transitional functions
from uplands to wetlands. Finally, 545 acres of forested upland restoration will be established
from fields and pastures above the 690 ft contour. The acreage of shallow littoral zone marsh
wetland is unaccounted for, but significant acreage of this kind (>50 acres below 683 ft MSL)
of habitat should naturally regenerate as the lake becomes filled.
A monitoring plan has been developed to evaluate the success of wetland mitigation
activities. Monitoring of soil hydrology and vegetation will be accomplished, with annual
reports being submitted to the U.S. Army Corps of Engineers (USACE) and U.S. t)X.O_
Environmental Protection Agency ( USEPA) and other designated agencies. A contingency t i
plan has also been proposed to insure acceptable levels of compensatory mitigation has been
achieved. 1
1 c?2r,?1a1`?
fi 5 ??, r,0'2
1.0 INTRODUCTION
The Piedmont Triad Regional Water Authority (PTRWA) proposes to construct
Randleman Lake, a 3,045 acre water supply reservoir at 682 ft MSL, on the beep River in
Randolph and Guilford counties. The member local governments of the PTRWA
(Jamestown, Archdale, High Point, Greensboro, and Randleman, and the County of
Randolph) plan to divert water from Randleman Lake on the Deep River to Rich Fork Creek
in the Yadkin River Basin and to North and South Buffalo Creeks in the Haw River sub-basin.
This project was originally authorized by the U.S. Congress as a multi-purpose reservoir in
1968 to meet the future water demand of 48 mgd. Detailed information concerning PTRWA's
water requirements is contained in a special report (NC DEHNR 1991), where population,
industrial and economic growth were modeled as well as other conservation and purchase
alternatives.
1.1 Background
As required by Section 404 of the Clean Water Act (16 USC 1344), PTRWA has
applied for a permit to place fill material in wetlands and impound water in the Deep River for
the construction of the proposed dam and water supply reservoir. Although the Randleman .
Lake project will have no impact on species listed as threatened or endangered, or proposed
for such listing by the U. S. Fish and Wildlife Service and the State of North Carolina (Carter
1993), the mitigation plan will eventually incorporate comments potentially identified as
significant as part of the USACE public notice procedures. Environmental issues yet to be
identified will have to be resolved through the extended review process and thus will be
addressed by later versions of this mitigation plan. Assuming that this project is determined
by the USACE in consultation with the USEPA to be in the public interest, and that there are
no practicable upland alternatives, the conversion of approximately 119 acres of jurisdictional
wetlands to open water habitat, can be resolved. The regulatory agencies will need to consider
mitigation to compensate for unavoidable wetland impacts. The PTRWA has retained
Triangle Wetland Consultants (TWC) to prepare this comprehensive wetland mitigation plan
to outline the procedures to compensate for unavoidable wetland losses associated with the
proposed Randleman Lake.
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1.2 Purpose and Objectives
The purpose of this report is to propose a comprehensive wetland mitigation plan to
compensate for the unavoidable conversion of approximately 119 acres of wetlands to open
water habitat. Specific objectives of this report include:
• describe the wetlands impacted by the proposed project
• identify potential impacts to wetlands
• develop an on-site and off-site wetland creation, restoration, and enhancement
mitigation plan
• develop related mitigation strategies
• provide management criteria for the permanent conservation status of the
buffer
area surrounding the impoundment
• develop a mitigation monitoring and contingency plan.
It is intended that this report will facilitate the review and approval of the
pending 404 permit application and provide specifications adequate for
technical review.
2.0 SITE CONDITIONS
2.1 Location and Attributes
The project area is located in the western Piedmont of North Carolina, in
Guilford and Randolph Counties (Fig. 1). The project will require the permanent inundation
of 3,045 acres of land, along approximately 23 miles of stream (10 miles on Muddy Creek and
13 miles on the Deep River). Another 3,000 acres comprised of a 200 ft. conservation buffer
will be protected around the lake above the 682 ft conservation pool elevation. The project
also includes the construction of an earth dam and spillway; the clearing and grubbing of
vegetation in the conservation pool; the relocation of roads and utilities; relocation of
inhabitants of about 55 dwellings; and the construction of a water treatment plant, intake
structure, and associated pumping, transmission and distribution system to serve PTRWA
governments.
The entire project area is an agricultural, industrial, and urbanized complex of human
impacts. The area is rapidly growing industrially around the Interstate 85 highway corridor,
3
with agriculture and dairy farming yielding to pasture land and urbanization. In the project
area, the relief is largely determined by the kind of bedrock underlying the soils, by the
geology of the area, and the amount of landscape dissection by streams. The two broad
classes of soil parent materials in the project area are residual materials and alluvium both of
which have developed under hardwood forests. Granite makes up about half of the underlying
rock with Cecil and Appling upland soils formed from these acid igneous substrates. The
basic rocks of diorite and gabbro are the parent material for the upland Iredell and
Mecklenburg series soils. Transported alluvium on floodplains are mapped by the Soil
Conservation Service as Congaree, Chewacla, and Wehadkee series soils.
2.2 Habitat Types
The project site is comprised of a combination of stream channel, wetland, and upland
habitat types (see habitat maps and report, Carter, 1993, and wetlands maps John R.
McAdams, 1992). The streams at the proposed reservoir site are relatively shallow and vary
from 20 feet wide to approximately 80 ft wide. Stream bottoms are composed primarily of
coarse to medium grain sands with significant amounts of fines and limited organic material.
Aquatic and wetland vegetation within the stream channel are absent, and the streams exhibit
small amounts of deadfall and accumulated litter.
The streams are typically sharply incised within the floodplain. Stream banks exhibit
steep slopes of one to one (1:1) or greater and are sometimes in excess of six to eight feet in
height. Groundcover is sparse along the steep side slopes, and overhanging vegetation
generally covers the bank top.
The Randleman Lake impoundment will convert present stream habitat to a lentic
environment, and changes are anticipated in the fishery. Those species adapted only to a free-
flowing stream habitat will decline in abundance and may eventually disappear from the
reservoir. However, most fish in the area are adaptable to the lake environment and overall
species composition should not change drastically (PTRWA, 1990). Fish habitat should
continue to improve in the Deep River downstream, as the construction of the Randleman
Lake will replace 23 miles of free-flowing streams with a 3,045 acre reservoir. Point and non-
point source pollutants that would normally get into the river would be diluted by the lake
waters and would tend to settle out in the upper reaches of the lake. Consequently, the water
discharged downstream from the reservoir should be of a higher quality (i.e. lower nutrients
and sediment load) than now exists in the stream ( PTRWA, 1990). More detailed
information about the reservoir's potential beneficial impacts on downstream water quality
5
relative to the change in lake environment can be found in the USACE Environmental Impact
Statement.
Palustrine forested, broad-leaved deciduous wetlands (PFO1) are the predominant
wetland types within the reservoir limits; however, smaller areas of palustrine scrub-shrub,
broad-leaved deciduous (PSS 1) and palustrine emergent, persistent (PEM1) wetlands are also
present (Appendix A, Section 2.3). Perennial and intermittent riverine wetlands occur in
drainageways throughout the 6,000 acre project area. The riverine wetlands would be
classified as upper perennial (R3 UB) and/or intermittent (R4SB) riverine systems (Cowardin,
1979). Due to the moderate degree of topographic relief within the project area, palustrine
wetlands are mostly confined within narrow floodplains along perennial streams and rivers.
However, there are several palustrine wetlands located at slope break positions (spring/seeps).
2.3 Hydrogeomorphic Types
The palustrine wetlands within the proposed reservoir limits were classified according
to a hydrogeomorphic (HGM) approach (Brinson, 1993). The HGM approach classifies
palustrine wetlands according to the geomorphic setting, water sources, and hydrodynamics.
Based on a 1995 field reconnaissance, the mapped wetland areas can be grouped into three
HGM types (Table 1). Based on observed field characteristics of mapped wetland areas and
existing literature, functional profiles were developed for each HGM type.
2.3.1 Spring/seep Wetland Type
There are relatively few wetland areas classified as seep wetlands within the
Randleman Lake project area (Appendix A). Several wetland areas were classified as
seep/fringe wetlands and/or seep/backswamp wetlands due to observed groundwater
discharge and location at the base of a steep slope (Photos #4 and #6, Appendix B). This
HGM type is located at slope break positions, generally at the base of the slope along the
upper edge of a floodplain. The substrate is generally saturated throughout the growing
season by groundwater discharge. These wetlands could potentially be dominated by a variety
of plant communities from forested to emergent, although the examples noted within
proposed Randleman Lake were all located at the edge of the Deep River floodplain in grazed
fields dominated by soft rush (JIMCus effusus) and sedge species (Carex spp.). These
wetlands are generally small in size and transitional to channels (riverine) draining into Deep
River. The potential functions and wildlife habitat values of these wetlands is minimal due to
vegetation clearing and grazing (trafficking impacts). In some instances, these wetlands have
6
been excavated to provide watering holes for cattle. Field observations indicate that these
watering holes support populations of green frogs (Rama clamitans) and bullfrogs (Rana
calesbeiaira), and therefore, provide limited wildlife habitat value.
Table 1. Wetland Types Grouped According to a
H dro eomor hic Classification after Brinson 1993
HGM Type Geomorphic Water Hydrodynamics
setting source(s)
spring/seep slope break groundwater nearly
wetland discharge constant water
table at or
near surface
alluvial fringe streamside overbank flow alternating
wetland fringe of from stream recharge &
high to middle discharge
gradient stream varying with
stream stage
alluvial middle gradient overbank flow seasonal
backswamp alluvial from stream & recharge
wetland landform shallow dependent upon
subsurface stream stage &
lateral flow gradual dry-
from adjacent down dependent
u lands u on ET
2.3.2 Alluvial Fringe Wetland Type
Alluvial fringe wetlands include narrow areas adjacent to high gradient perennial or
intermittent streams, and relatively small (<0.25 acre) wetland areas in the floodplain of larger
streams (Deep River, Muddy Creek, etc.). These areas are characterized by a short
hydroperiod, usually temporarily flooded or seasonally saturated. The relatively short
hydroperiod is the result of the high gradient landscape position (adjacent to first order
streams), absence of well developed soil aquatard (i.e. lack of silt or clay horizon to perch
water), and lack of well-developed fluvial landforms (i.e. broad floodplain with levee and
backswamp features). Field evidence of a short hydroperiod includes marginal hydric soil
characteristics (redoximorphic features), coarse textured sediments, lack of surface water, and
lack of surficial hydrologic indicators (water-stained leaves, etc.). This wetland type is
typically dominated by forest vegetation, but some areas have been cleared for pasture.
Dominant tree and shrub species include sycamore (Platanus occidentalis), boxelder (Acer
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negundo), green ash (Fraxinus petursylvairica), ironwood (Carpinus caroliniana), yellow
poplar (Liriodench-on tulipifera), sweetgum (Liquidambar styraciflua), and Chinese privet
(Ligustrum sinense).
The characteristic functions and values of this HGM type include carbon export,
energy dissipation, short-term surface water storage, particulate retention, nutrient cycling,
and wildlife habitat values (Brinson et al., 1994; Taylor et al., 1990; Wilkinson et al., 1987).
Certain functions (particularly biogeochemical functions) are limited in this HGM type due the
short hydroperiod (Elder, 1987). These secondary functions include long-term surface water
storage, soil water storage, moderation of groundwater discharge, and removal of elements
and compounds. The alluvial fringe wetlands mapped within the Randleman Lake project area
are generally small in size (<0.25 ac.) and/or located along high-gradient tributaries to Deep
River that lack well developed fluvial landforms (i.e. stream levee with basin-like backswamp).
Primary productivity and the associated functions (nutrient cycling, litterfall, and carbon
export) of these alluvial wetlands are expected to be relatively high as compared with primary
productivity of the adjacent upland forests or stagnant water systems (Conner and Day, 1976).
Annual nutrient subsidies from floodwaters and favorable soil moisture conditions generally
result in higher productivity and associated functions (Brinson et al., 1981). Long-term
surface water storage and soil water storage are limited due to the small size of individual
wetland areas and lack of basin morphometry. In addition, most of these fringe wetlands have
direct surficial connections to the stream channel that deter from long-term surface water
storage. The high-gradient and poorly developed fluvial landforms affect substrate
characteristics within these wetlands. Field evidence such as drift lines, scour channels, and
sediment deposits suggest that floodwater velocities are generally high as compared with
those in middle gradient landforms and tend to scour the floodplain. In the absence of slower
velocity backwater areas, fine suspended sediments do not settle out of the water column, but
pass through the wetland. High floodwater velocities and high woody stem densities tend to
enhance the energy dissipation functions of these wetlands. In addition, high woody stem
density facilitates the particulate retention function of the wetland. Scouring of the floodplain
surface from high velocity floodwaters, surficial connections to the stream channel, and high
primary productivity/litterfall enhance particulate organic carbon export (Cuffney, 1988), but
the short retention time of floodwaters may lower dissolved organic carbon export
(Mullohand and Kuenzler, 1979). Nutrient cycling/removal is an important function of these
wetlands, but may be limited due to sediment characteristics and hydroperiod (Brinson et al.,
1984; Elder, 1987).
Regardless of the magnitude of the latter wetland functions, these riparian wetlands
and non-wetland forests provide critical buffers along first order streams and function as filters
8
for sediments and nutrients from floodwaters and non-point source runoff (Kuenzler, 1989;
Lowrance, 1992; Gilliam, 1994). The alluvial fringe wetlands within the Randleman Lake
project area tend to be small in size. Approximately 72% of the total number of wetlands
mapped within the Randleman Lake project area are less than 0.25 acre in size. These small
wetland areas are not structurally different from the surrounding upland alluvial forest. Hard
mast producing species such as water oak (Quercus nigra), willow oak (Quer'cus phellos),
and swamp chestnut oak (Quercus michauxii) comprised an insignificant component of the
plant community in this HGM type. However, there are some common soft mast producing
species including blackhaw (Viburnum prunifolium), silky dogwood (Corpus amomum), and
multiflora rose (Rosa multif7ora). Although some wetland areas contain large individual
cavity trees and/or dead snags, most of this wetland type has been selectively logged and is
relatively immature. Individually, most of these small wetland areas lack any outstanding
habitat characteristics and provide limited wildlife value. However, the cumulative
(considering both upland and wetland areas) wildlife habitat and riparian corridor value would
be relatively high.
2.3.3 Alluvial Backswamp Wetland Type
The alluvial backswamp wetland type includes both small and relatively large areas
located in the floodplain of larger, middle gradient streams (Deep River, Muddy Creek,
Hickory Creek, etc.). This wetland type is characterized by a longer hydroperiod than the
previous type, usually temporarily flooded/saturated to seasonally flooded. The relatively long
hydroperiod is the result of the lower stream gradient, presence of a soil aquatard (i.e. silt or
clay horizon), and well-developed fluvial landforms (i.e. broad floodplain with levee and
backswamp features). Field evidence of a long hydroperiod includes strong redoximorphic
features in the soil, fine textured soil horizon, presence of surface water, and surficial
hydrologic indicators (water-stained leaves, water marks, etc.). This wetland type is mostly
dominated by forest vegetation, although some areas have been cleared for pasture (Photo #5,
Appendix B). Dominant tree and shrub species include sycamore, boxelder, green ash, red
maple (Acer rubrum), river birch (Betula nigra), sweetgum, and blackgum (Nyssa sylvatica),
The characteristic functions and values of this HGM type include carbon export,
energy dissipation, short- and long-term surface water storage, soil water storage, particulate
retention, removal of elements and compounds, nutrient cycling, and wildlife habitat values
(Brinson et al., 1994; Taylor et al., 1990, Wilkinson et al., 1987). In addition, some alluvial
backswamp wetland may provide moderation of groundwater discharge due to the presence of
9
groundwater seeps and shallow subsurface lateral flow into the wetland. The alluvial
backswamp wetlands mapped within the Randleman Lake project area are generally larger in
size (>0.25 ac.) than the alluvial fringe wetlands and are located in areas with well developed
fluvial landforms (i.e. stream levee with basin-like backswamp). Short-term surface water
storage, long-term surface water storage, and soil water storage are important functions
because of the basin morphometry and presence of a slowly permeable soil horizon or soil
aquatard (usually a fine silt or clay horizon). Some of the backswamp wetlands have surficial
connections to the stream channel that limit the long-term surface water storage, but enhance
the potential for dissolved and particulate organic export (Gosselink et al., 1990; Mullohand
and Kuenzler, 1979; Cuffney, 1988). Floodwater velocities are generally lower than those
associated with high gradient fringe wetlands but may be sufficient to transport fine woody
debris (indicated by drift lines) and particulate organic carbon. The high woody stem
densities, high microtopographic relief, and broad floodplain increase the ability of these
wetlands to slow floodwaters (energy dissipation function) and trap particulates (particulate
retention function). Slower water velocities result in settling of fine suspended sediments
from the water column. Fine-textured sediments and a relatively long hydroperiod favor
nutrient retention and processing as well as the retention of metals (Gambrell, 1994; Elder,
1987; Brinson et al., 1984). Periodically flooded alluvial forests tend to have higher
productivity rates and litterfall as compared with rates for upland or stagnant water systems
(Conner and Day, 1976; Brinson et al., 1981; Reddy and Patrick, 1975).
Some examples of the alluvial backswamp wetland type are structurally different from
the surrounding upland alluvial forest. Several of these backswamp areas contain seasonally
flooded ponds (Photo #1, Appendix B). Although not widespread within the project area,
these seasonal ponds provide critical breeding habitat for species such as wood frog (Rana
palustris), spotted salamander (Ambystoma maculatum), and Jefferson's salamander
(Ambystoma jeffersoiiianum) (Dunson et al., 1992; Forester, 1992; Dopyera, 1995). Some of
the larger backswamp areas contain abundant standing dead snags and cavity trees. The
presence of these cavity trees and snags is likely the result of past land management practices
(selective logging, etc.) and size of the wetland (i.e. smaller wetland/upland areas are less
likely to contain large diameter cavity trees and/or snags). Hard mast producing species such
as water oak, willow oak, and swamp chestnut oak are mostly absent from these wetlands.
However, there were some common soft mast producing species including spicebush (LiWera
bettzoiti), silky dogwood, and blackgum.
Some alluvial backswamp wetlands have been degraded by clearing/grazing. Grazing
by cattle results in a reduction of herbaceous and understory vegetation, and
destabilization/erosion of the substrate due to trafficking (Photo #3, Appendix B). Some
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backswamp wetlands have been entirely cleared for pasture (Photo #5, Appendix B). These
disturbances have undoubtedly reduced the functions performed and values provided by the
affected wetlands.
2.4 Exceptional Habitat Areas
There are few examples of areas that possess exceptional habitat features within the
Randleman Lake project area. An exceptional habitat was considered to be a relatively mature
example of a particular type or a habitat type in decline and/or considered regionally rare.
Most of the forested habitat within the project area is representative of the forest community
types described by Schafale and Weakley (1990) which includes the Piedmont/Low Mountain
Alluvial Forest and Piedmont/Mountain Bottomland Forest is dominant. The adjacent upland
slopes are dominated by Dry-Mesic Oak-Hickory Forest and the coves are dominated by
Mesic Mixed Hardwood Forest: Piedmont Subtype. Most of these forested areas have been
selectively logged or "high graded" for large diameter oaks. The existing forest stands are
mostly dominated by pole-sized juvenile trees (5-10" DBH) or small sawtimber stands (10-15
DBH). Although the oak component (northern red oak, chestnut oak, white oak) is still
abundant in upland forests, oak species are not abundant in the bottomlands. The lack of any
significant oak component in the bottomlands suggests extensive selective logging for oak
species along the Deep River and its tributaries. Two examples of mature (average diameter
>15" DBH) Dry-Mesic Oak-Hickory Forest are present within the project area. One small .
remnant stand is located along Richland Creek, northwest of the High Point Sewage
Treatment Facility. At least part of this stand will be protected by the proposed buffer zone.
Another extensive example of this type is located along Hickory Creek, between Hickory
Creek Road and Wall Road. A large portion of this stand will be protected by the proposed
buffer zone.
Several seasonal ponds were noted (Wetlands #4-1, #4-2, and #6-1) within the project
area. As discussed, these seasonal ponds provide critical breeding habitat for certain declining
amphibian species (Forester, 1992; Dopyera, 1995). In addition, these seasonal ponds are
particularly sensitive to habitat acidification because of their low buffering capacity (Dunson
et al., 1992). Although these three examples will be inundated by the proposed reservoir,
some semi permanently/permanently flooded ponds will be preserved within the proposed
buffer zone. In addition, excellent seasonal pond creation opportunities exist in open fields at
the upstream limits of the proposed reservoir. The water level at this point is anticipated to be
at or near bankfull capacity of the existing channel. Therefore, the water table in adjacent
fields will fluctuate at or near the surface. Shallow basins, if properly designed, could simulate
the hydroperiod of the natural seasonal ponds. After forest stands are established around
these areas, they could potentially replace the lost breeding habitat.
3.0 POTENTIAL IMPACTS
Potential impacts resulting from the proposed reservoir include impacts to wetland and
aquatic resources and upland wildlife and habitat. Primary impacts to wetland and aquatic
resources include conversion of the existing forested wetland habitats and shallow lotic
aquatic systems to an open water, lentic aquatic system. The open water reservoir system will
retain and/or enhance the values for most of the current wetland functions including flood
water storage, sediment/toxicant retention, nutrient assimilation, and ground water discharge/
recharge. The functions of wildlife habitat and primary productivity are expected to be
adversely impacted. Such impacts are more fully discussed within the 404 permit application,
EIS and other supporting documents.
Presently the wetlands and aquatic habitats within the proposed project area provide
high quality habitat for a wide variety of herpetofauna, birds and mammals. Some species
within these groups are dependent on wetlands for food, protection, resting and reproduction
(wetland dependent species), whereas other species use wetlands for only apart of their vital.
life functions. Some species spend their entire life cycle within a single wetland, whereas
other species spend a portion of their life cycle in wetlands or may only travel through
wetlands (Sather 1984).
Fritzell (1988) described three categories for mammals using wetlands: 1) limited,
species for which wetlands are essential, and the loss of which will eliminate use of the area by
the species; 2) influenced, species for which wetlands are important, and the loss of which will
decrease carrying capacity, but not eliminate the use of the area by the species, and 3)
unaffected, species who regularly use wetlands, but for which wetlands are not necessary, and
will not likely decrease the carrying capacity of the area. Most species associated with the
project area will be displaced to adjacent and surrounding wetlands or upland habitats.
Bottomland hardwood forests are inherently productive. A major factor contributing
to the high productivity of forested floodplains is the pulsing wet-dry cycle (Wharton et al.
1982). Primary productivity potential within the floodplain will be reduced by construction of
the proposed reservoir as will the detritus export and transformation potential of excess
dissolved organic nutrients. There is also an accompanying shift in primary productivity from
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DRAFT (In-house Review Only)
SUBCHAPTER 2B - SURFACE WATER AND WETLANDS STANDARDS, MONITORING
SECTION.0200 - CLASSIFICATIONS AND WATER QUALITY STANDARDS APPLICABLE TO SURFACE
WATERS AND WETLANDS OR NORTH CAROLINA
.0xxx PROPOSED RANDLEMAN LAKE WATER SUPPLY WATERSHED: PROTECTION AND
MAINTENANCE OF RIPARIAN AREAS
The following is the management strategy for maintaining and protecting riparian areas in the proposed Randleman Lake
watershed:
(1) Riparian areas shall be protected and maintained in accordance with this Rule on all sides of surface waters in the
proposed Randleman Lake water supply watershed (intermittent streams, perennial streams, lakes, ponds) as indicated on the
most recent versions of United States Geological Survey 1:24,000 scale (7.5 minute quadrangle) topographic maps or other
site-specific evidence. This Rule only applies to r-ipaFian aFeas whefe ??est b
Sub item 3(a+as e9july 22, 1997. Forest N,egetatiea, as def4ned in 1 5A NC-AG 2B .0202, of anywidth in Zone 1 mu
+ pr-etee;ed maintained er-danee with this Rule The Piedmont Triad Regional Water Authority (PTRWA) shall and develop a detailed stream network ma for the watershed based on the field criteria supplied b the Division of Water uali
The PTRWA shall submit this map to the Division for approval within six months after the effective date of this Rule.
Riparian areas shall be protected and maintained in accordance with this Rule on all sides of surface waters in the proposed
Randleman Lake water supply watershed as indicated on this approved may. This Rule does net establish '' ffeFS iR ReW .I ia?-a ear- Exceptions to the requirements of this Rule for riparian areas are described in Sub-Items (2) (a-h).
Maintenance of the riparian areas should be such that, to the maximum extent possible, sheet flow of surface water is achieved.
This Rule specifies requirements that shall be implemented in riparian areas to ensure that the pollutant removal functions of
the riparian area are protected and maintained. All local governments that have land use authority within the proposed
Randleman Lake water supply -watershed shall adopt and enforce this Rule through local water supply and other local
ordinances Ordinances shall require that all riparian protection areas are recorded on new or modified plats. No building
permits shall be issued and no development shall take place in violation of this Rule.
(2) The following waterbodies and land uses are exempt from the riparian area protection requirements:
(a) Ditches and manmade conveyances, other than modified natural streams, which under normal conditions do not
receive drainage waters from any tributary ditches canals or streams unless the ditch or manmade conveyance
delivers runoff directly to waters classified in accordance with 15A NCAC 213 .0100;
(b) Areas mapped as intermittent streams, perennial streams, lakes, ponds, or estuaries on the most recent versions of
United States Geological Survey 1:24,000 scale (7.5 minute quadrangle) topographic maps where no perennial
S7
waterbody, intermittent waterbody, lake, pond or estuary actually exists on the ground;
(c) Ponds and lakes created for animal watering, irrigation, or other agricultural uses that are not part of a natural
drainage way that is classified in accordance with 15A NCAC 213 .0100; and
(d) Water dependent structures as defined in 15A NCAC 213 .0202, provided that they are located, designed, constructed
and maintained to provide maximum nutrient removal, to have the least adverse effects on aquatic life and habitat
and to protect water quality.
(e)The following uses may be allowed where no practical alternative exists. A lack of practical alternatives may be shown
by demonstrating that, considering the potential for a reduction in size, configuration or density of the proposed activity
and all alternative designs, the basic project purpose cannot be practically accomplished in a manner which would avoid
or result in less adverse impact to surface waters. Also, these structures shall be located, designed, constructed, and
maintained to have minimal disturbance, to provide maximum nutrient removal and erosion protection, to have the least
adverse effects on aquatic life and habitat, and to protect water quality to the maximum extent practical through the use
of best management practices. ^^nn
(i) Road crossings, railroad crossings, bridges, airport facilities, and utility crossings may be allowed if
conditions specified in 2(e) of this Rule are met. LA
(ii) Stormwater management facilities and ponds, and utility construction and maintenance corridors for utt '
such as water, sewer or gas, may be allowed in Zone 2 of the riparian area as long as the conditions specified
in 2(e) of this Rule are met and they are located at least 30 feet from the top of bank or mean high water line.
Additional requirements for utility construction and maintenance corridors are listed in 2(f) of this Rule.
(f) A corridor for the construction and maintenance of utility lines, such as water, sewer or gas, (including access roads
and stockpiling of materials) may run parallel to the stream and may be located within Zone 2 of the riparian area, as
long as no practical alternative exists and they are located at least 30 feet from the top of bank or mean high water
line and best management practices are installed to minimize runoff and maximize water quality protection to the
maximum extent practicable. Permanent, maintained access corridors shall be restricted to the minimum width
practicable and shall not exceed 10 feet in width except at manhole locations. A 10 feet by 10 feet perpendicular
vehicle turnaround is allowed provided they are spaced at least 500 feet apart along the riparian area.
DRAFT (In-house Review Only)
(ii) The following practices and activities are allowed in Zone 2 in addition to those allowed in Zone 1:
(A)Periodic mowing and removal of plant products such as timber, nuts, and fruit is allowed on a periodic
basis provided the intended purpose of the riparian area is not compromised by harvesting, disturbance,
or loss of forest or herbaceous ground cover; and
(B)Forest vegetation in Zone 2 may be managed to minimize shading on adjacent land outside the riparian
area if the water quality function of the riparian area is not compromised.
(9)ON gGiH,-, a,-FieH1VdFa1 Oper-atk)RS PF81Ad0d that FeElUir-eHAL-2114s of Rules .02?6 and .0238 of this Seetion afe
followed.
(iii) The following practices and activities are not allowed in Zone 2:
(A)Land disturbing activities and placement of fill and other materials, other than those allowed in Items 2
and 3(b)(ii) of this Rule;
(B)New development, except as provided in Sub-Items 2(e) and 2(f) of this Rule;
(C)New on-site sanitary sewage systems which use ground adsorption;
(D)The application of fertilizer; and
(E)Any activity that threatens the health and function of the vegetation including, but not limited to,
application of chemicals in amounts exceeding the manufacturer's recommended rate, uncontrolled
sediment sources on adjacent lands, and the creation of any areas with bare soil.
(c) Timber removal and skidding of trees shall be directed away from the water course or water body. Skidding shall be
done in a manner to prevent the creation of ephemeral channels perpendicular to the water body. Any tree removal
must be performed in a manner that does not compromise the intended purpose of the riparian area and is in
accordance with the Forest Practices Guidelines Related to Water Quality (15A NCAC IJ .0201-.0209).
(d) Maintenance of sheet flow in Zones 1 and 2 is required in accordance with this Item.
(i) Sheet flow must be maintained to the maximum extent practical through dispersing concentrated flow and/or
re-establishment of vegetation to maintain the effectiveness of the riparian area.
(ii) Concentrated runoff from new ditches or manmade conveyances must be dispersed into sheet flow before the
runoff enters Zone 2 of the riparian area. Existing ditches and manmade conveyances, as specified in Sub-
Item 2(a) of this Rule, are exempt from this requirement; however, care should be taken to minimize pollutant
loading through these existing ditches and manmade conveyances from fertilizer application or erosion.
(iii) Periodic corrective action to restore sheet flow should be taken by the landowner if necessary to impede the
formation of erosion gullies which allow concentrated flow to bypass treatment in the riparian area.
(e) Periodic maintenance of modified natural streams such as canals is allowed provided that disturbance is minimized
and the structure and function of the riparian area is not compromised. A grassed travelway is allowed on one side
of the waterbody when alternative forms of maintenance access are not practical. The width and specifications of
the travelway shall be only that needed for equipment access and operation. The travelway shall be located to
maximize stream shading.
(4) if a !sea! govemmefit has been issued a Munieipal Separate StOR:HWatOF 90WeF 8)'Steffl peffRit er- has been delegated to
+alid •a .. .,. 668 6FE[ed e _ edifiied gluts.
(5)(4) Where the standards and management requirements for riparian areas are in conflict with other laws, regulations, and
permits regarding streams, steep slopes, erodible soils, wetlands, floodplains, forest harvesting, surface mining, land
disturbance activities, or other environmental protection areas, the more protective shall apply.
(6)(5) Where application of this Rule would prevent all reasonable uses of a lot
.d * Rt4e a variance may be granted by the Environmental Management Commission if it finds that:
(a) practical difficulties or unnecessary hardships would result in strict application of the Rule;
(b) such difficulties or hardships result from conditions which are peculiar to the property involved; and
(c) the general purpose and intent of the Rule would be preserved, water quality would be protected and substantial
justice would be done if the variance were granted.
DRAFT (Inhouse Review Only)
stringent local stormwater management program plan. Local stormwater management programs and modifications to
these programs shall be kept on file by the Division of Water Quality.
(4) If a local government fails to submit an acceptable local stormwater management program plan within the time frames
established in this Rule or fails to properly implement an approved plan, then stormwater management requirements for
existing and new urban areas within its jurisdiction will be administered through the NPDES municipal stormwater
permitting program per 15A NCAC 2H .0126.
(a) Subject local governments will be required to develop and implement comprehensive stormwater management
programs for both existing and new development.
(b) These stormwater management programs shall provide all components that are required of local government
stormwater programs in Item (2)(a)-(e) above.
(c) Local governments that are subject to an NPDES permit shall be covered by the permit for at least one permitting
cycle (five years) before they are eligible to submit a local stormwater management program for consideration and
approval by the EMC.
(5) All other water supply protection requirements as specified in 15A NCAC 2B .0100 and .0200 apply to the Randleman
Lake water supply watershed.
1 .0241 Randleman Lake Watershed
2 STRATEGY: WASTEWATER DISCHARGE REQUIREMENTS
3 The following is the National Pollutant Discharge Elimination System (NPDES) wastewater discharge
4 management strategy for the Randleman Lake Watershed. For purposes of this rule, permitted discharges
5 means those individually permitted and not those covered under general permits:
6 (1) There shall be no new individually permitted wastewater dischargers in the watershed with the
7 exception that the City of High Point will be allowed to expand its wastewater treatment plant and
8 serve as a regional plant for the watershed.
9 (2) The City of Hioh Point shall evaluate and optimize the operation of its Eastside facility in order
10 to reduce nutrient loadings. One year after the effective date of this Rule, a report shall be
11 submitted to the division by High Point documenting the efforts/level of reductions achieved.
12 (3) The total phosphorus load for the City of High Point's Eastside facility shall, on an annual mass
13 basis be no more than 15,800 pounds per year (7200 kilograms per year). Compliance with the
14 15,800 pounds annual average mass load of total phosphorus shall be required within five years
15 of the effective date of this rule and maintained thereafter.
16
17
Pete C
From: John_D
Sent: Tuesday, June 30, 1998 7:22 PM
To: 'Lin_xu@h 2o.enr.state. nc.us'
Cc: Pete_C; 'dennis'
Subject: Comments on Randleman Riparian Area Protection rules
Following are comments on the draft Randleman rules. They reflect the information we have learned from the Neuse River buffer
rules as well as the 401 Certification program.
1. Have the Authority contract with a consultant to map all locations (survey and/or GPS) where streams begin. DWQ can
check them as needed. This map will then provide a definitive location from which buffers can be drawn for future
development.
2. Allow one year (rather than six months) for the Authority to develop the stream map.
3. Add in-stream ponds and utilities to those activities allowed in the buffer if there is no practical alternative [(e)(I)]. This is
crucial - many of the problems we have had with the Neuse buffer rules stem from this omission. If anyone wants to (again)
argue with me about this, pick up the phone.
4. Delete (e)(ii). See above comment.
5. Where did the underlined language ion (2)(a) come from and what does it mean?
6. (2)(g) Modify to read: Stream and wetland restoration projects,...
7. Modify (5) to read "Where application of this Rule would prevent all reasonable uses of a lot, a variance may be granted by
the ...
Based on our recent fieldwork, the topo maps are about 40% accurate in the piedmont in their stream depiction. Therefore
any attempt to limit the buffers to only those streams shown on USGS topo maps should be resisted at all cost.
Please call if you have any questions.
r

John _D
From: Boyd DeVane [[e-mail]. nc.us]
Sent: Monday, October 19, 1998 11:22 AM
To: Corey; Ron Linville; LARRY COBLE; Steve Mauney <4
Cc: Jay Sauber; Jimmie Overton .i Loy
Subject: RANDLEMAN
14 91
ROP-Summary.WP5 ROP.TOTAL.TXT
I finished the first draft of the major elements of the Hearing
Officers' Report and would appreciate your suggestions and comments.
I've enclosed it below and I've also attached it as a text document and
as a word perfect 5.0 for PC's. Hopefully one of these will give you a
view. Coleen, Jason and I have met twice with the hearing officers and
I've tried to prepare it as they recommended. Before I send it to them,
I'd like your comments. I doubt they will be interested in making it
any s(rzng---rj ' ;1 t, there is a move afoot to not require buffers in
tii"ppex._ 4ters ed around internuitant streams. Ill let you know what
happens about that. If you have suggestions or comments, please email
them to me or fax changes you suggest. Please do not make changes in
the document and send them back to me electronically because, unless
we're lucky, the indication of your changes will be eliminated and I
will have to reread the entire document to tell what you suggested
changing Anyway, I appreciate the h°Ip you've given. If you'd like me
to fa:.-. or rnail you a copy, lct me kno-N . Also, we are on a fast
turnarounu and I expect we wlli try to get this to ni:9 hearing oli-veers
by Wednesday evening. call if you have questions or want to curse me
for the poor job I did.
SUMMARY OF MAJOR COMMENTS AND STAFF RESPONSES
HEARING OFFICERS' RECOMMENDATION
It was the intent of the Division of Water Quality (DWQ) to outline, and
propose to the Environmental Management Commission (EMC), a "Randleman
Lake Watershed Management Strategy" that would provide the additional
protection measures deemed necessary to assure that the Randleman Lake,
if built, would support all designated water quality uses and
standards. The staff prepared a July 24, 1998 document which set forth
proposed rules which became that "Management Strategy." This "Report of
Proceedings" includes the proposed rules, and along with the
recommendations set forth herein, after approval by the EMC, constitutes
the final "Randleman Lake Watershed Management Strategy."
POINT SOURCE CONTROLS
Effluent Limits for High Point Eastside
One of the most critical issues facing the Environmental Management
Commission relative to the decision to reclassify the waters of the Deep
River, to enable the creation of the Randleman Reservoir, is the
phosphorus limits that would apply to the City of High Point's Eastside

Wastewater Treatment Plant (WWTP). The recommendations that were sent
out to public hearing specified two point source options: one associated
with Option A and one associated with Option B. The Option B proposal
offered two sub-options. The Option A proposal would require the City
of High Point's Eastside facility to meet a monthly average total
phosphorus concentration of 0.5 mg/1 which would be set in the rule and
later in the permit. The proposal also included a goal for the facility
of 0.2 mg/I phosphorus concentration for a monthly average. This option
was offered by the Piedmont Triad Regional Water Authority.
Both alternatives offered in Option B for point sources were considered
to be more stringent than the Option A. The point source sub-option 1,
under the Option B, required that the City of High Point relocate the
discharge from its Eastside plant to a point located downstream of the
proposed Randleman Dam. The point source sub-option 2, on the other
hand, allowed the discharge to remain at its present site but required
that the City meet a monthly average total phosphorus concentration of
0.18 mg/I year round. The Option B proposal also included a provision
that "There shall be no new or expanding permitted wastewater discharges
in the watershed with the exception that the City of High Point Eastside
WWTP may be allowed to expand beyond the 26 million gallon gallons per
day provided that is meets a monthly average total phosphorus
concentration that would not exceed a permitted total phosphorus load of
14,200 pounds per year."
The staff and the hearing officers spent considerable time in evaluating
these proposals and how they might affect the discharger, other members
of the Authority, and the Deep River and Randleman Lake environments.
The final recommendation of the hearing officers is a combination of
each of these options and offers similar environmental benefits as
Option B but with reduced costs from those of Option B.
The option to discharge around the lake received by far the most
negative comments. In addition to resolutions from various chambers of
commerce and water and sewer authorities, 17 local government bodies in
the lake area and downstream on the Deep and Cape Fear Rivers sent
resolutions opposing this option. (See Appendix B for resolutions.)
Commenters at the public hearing noted that the reservoir was predicted
to assimilate approximately 80% of the phosphorus that entered its
tributaries. Downstream users of the river felt that the quality of
their drinking water would be adversely affected by this discharge.
These factors, along with the estimated $25-30 million dollar cost
increase associated with this option, caused it to be dropped from the
list of viable options by the hearing officers.
The option of allowing the High Point East Side discharge to remain at
its present location in Richland Creek but to meet a 0.18 mg/l monthly
phosphorus limitation also received significant comment. Approximately
55% of the comments received voiced support for the Commission applying
the most stringent conditions of the proposals (or not allow the dam to
the built at all), while about 45% of the comments supported proceeding
expeditiously with the proposed regulatory controls outlined in Option A
(offered by the PTRWA).
The Division uses water quality models to predict the eutrophic response
in the proposed lake from various point and nonpoint sources. They also
R
used models to predict the eutrophic response for various point source
control levels, such as the 0.18 mg/I limitation and various nonpoint
source control measures such as a 50 ft. buffer requirement. The
results of several modeling analyses are included on pages _ and of
this report. As can be seen from the summary on page , if the High
Point Eastside discharge were to remain at its present site and
discharge at a 0.5 mg/I phosphorus level into the Deep River Segment 1,
the average chlorophyll a value expected in that arm of the lake, during
the growing season, would be 76 ug/1. Also, the models predict that the
waters would violate the 40 ug/1 chlorophyll a standard 80% of the
time. The staff have concluded that this level of eutrophication would
result in unacceptable water quality conditions in that arm of the
lake. (This prediction was based on the nonpoint source controls
recommended by the PTRWA - Option A.) The staff recommendation that
went to hearing was to control the effluent phosphorus from the High
Point facility to a 0.18 mg/I level, based on a monthly average.
Considerable comments were received during the public involvement
process on the additional costs and the technical feasibility of meeting
that level of phosphorus in the effluent. The City of High Point has
estimated that the additional treatment facilities required and the
additional costs of treatment would create an additional Present Worth
cost to the City of $14,122,000. (See comments in Appendix A, page
) As to the technical feasibility of meeting the limits,
information obtained from a Maryland consulting firm indicated that
there were six facilities in Potomac River which have a 0.18 mg/1
phosporus limitation. DWQ staff talked with staff of the Upper Occoquan
Service Authority who indicated that their plant was achieving a level
of lower than 0.18mg/1 phosphorus on a monthly basis and that the
average monthly level for 1997 was 0.036 mg/1. (See Appendix A, page
.) In addition, discussion with Virginia DEQ staff indicated that
the Roanoke Virginia WWTP had a standard of 0.20 mg/1 phosphorus and had
met that standard for the past 12 months.
The hearing officers considered the comments offered by the affected
local governments and the predicted violations of the chlorophyll a
standard and suggested another alternative which could reduce the costs
to the local governments yet offer an opportunity to drastically reduce
the expected chlorophyll a violations in the Deep River Segment 1
waters. The option offered was to relocate the discharge point from the
present location on Richland Creek to a point downstream, approximately
1.5 miles, near Freeman Mill. Because of the restricted width of the
lake upstream of the Freeman Mill area, the modelers used this location
as the dividing line between the Deep River Segment 1 and the Deep River
Segment 2. The rationale behind placing the discharge in this area of
the lake is it prevents the High Point point source nutrient load from
further degrading the quality of the sensitive waters in Segment 1 of
the lake. If the Option A (PTRWA) nonpoint source controls were
applied, the predicted average chlorophyll a value for Deep River
Segment 1 would be 45 ug/1 and in Segment 2, the predicted chlorophyll a
average would be 32 ug/1. (See Appendix A, page .) However, if the
nonpoint source controls recommended by the staff in Option B were
applied, the predicted average chlorophyll a value for Deep River
Segment 1 would be 39 ug/I and in Segment 2, the predicted chlorophyll a
average would be 31 ug/1. (See Appendix A, page .)
since it readily adheres to particles and is transported downstream to
larger streams and lakes. Riparian protected areas are valuable in that
they provide shading, food source, channel protection, pollutant
filtering, habitat source, and act as a sponge for rainfall. The staff
recognizes that riparian area protection is critical in areas where a
potential already exists for violations of water quality standards.
This is the case for the Randleman Reservoir and the reason the staff
made this proposal for that watershed.
Many comments were for the enhanced riparian protection and some were
against. Those against pointed to the loss of developable land, the
increased permitting complexities, and the rationale for applying those
requirements in this watershed when they were not required in other
water supply watersheds in the state.
The hearing officers considered the comments provided and weighed them
against their desire to not allow the creation of a reservoir where
unacceptable levels of algal growth would be seen. They also recognized
the fact that once the buffers were gone, it was extremely difficult, if
not impossible, to restore them. Accordingly, they recommended that the
50 ft. buffer requirement be applied throughout the upper and lower
portions of the Randleman Reservoir watershed. This would include the.
Oak Hollow Lake, High Point Lake, and Oakdale watersheds. However,
after considering comments provided and considering the fact that most
phosphorus travels over land rather than subsurface migration, the
hearing officers recommended that in Zone 2 (the 20 ft. area adjacent to
the 30 ft. undisturbed riparian area), the rules allow additional
activities such as clearing and grading, as long as a 20 ft. revegetated
buffer is provided. The existing 100" vegetated buffer away from
perennial streams for high density development is still in existence for
these and other WS-IV watersheds.
STREAM DETERMINATIONS
Comments were received that modifications should be made in the proposal
that the Division would require the Authority to develop a map of the
watershed that provided where the riparian protection requirements
apply. The idea was that they would use the USGS topo maps and the USDA
soil survey maps to determine which streams needed buffer protection but
would also add additional conditions specified by the state at a later
date in development of that map. It was decided that using the topo map
and the soil survey maps to determine which streams would be affected by
the riparian protection requirements would be adequate. However,
because of comments received, the rule proposal was modified to allow
local governments to develop their own maps which, if approved by the
Division of Water Quality, could be used to enforce the riparian area
provisions of the rules in lieu of using the USGS and USDA maps. The
Division would need to assure that they provide an equivalent level of
protection as use of the maps would achieve.
STORMWATER REQUIREMENTS
The initial proposals that went to public hearing contained in Option B,
stormwater management requirements. The proposal in Option B was that
the stormwater requirements would apply for the entire Randleman
drainage area, which includes the upper and lower watersheds of that
basin. The hearing officers evaluated the environmental benefits of
requiring the stormwater (density) provisions in the upper portion of
the Randleman watershed as well as the lower portion of the watershed.
Because of the location of the Oak Hollow Lake and the High Point Lake,
the benefits of the density controls were somewhat "dampened" by the
reservoirs and the benefits to the Randleman Lake would be less than
they might be. Also, the hearing officers considered the fact that they
only recently approved the local stormwater management programs for the
Oak Hollow Lake, High Point Lake and the Oakdale watersheds. The
recommendation of the hearing officers is that the additional stormwater
provisions would be applied in the lower portion of the Randleman Lake
drainage area, downstream from the Oakdale Dam to the location of the
proposed Randleman Reservoir dam and the watersheds draining into that
segment.
Many comments were received indicating that the existing stormwater
requirements were more stringent than the statewide requirements for
water supply watersheds and that there was no justification for
requiring more stringent controls for this watershed. The staff noted
to the hearing officers that this proposal was a special case that
deserved special attention. They noted that the lake is not built and
the Commission should not want to allow construction of a body of water
where the average chlorophyll a values in some segments would exceed the
adopted water quality standard during the growing season. The
management strategy as proposed is predicted to enable each of the
segments outlined in the DWQ model to average less than the 40 ug/l
standard during the growing season. They suggest that this would enable
the Director to conclude that the lake would achieve an overall level of
chlorophyll a that would comply with the requirements of the Clean Water
Act. The hearing officers agreed to recommend that the stormwater
requirements be adopted by the Commission for the lower portion of the
watershed (from Oakdale Dam to Randleman Dam) as was proposed in Option
B and sent to public hearing.
Commenters also noted that the existing stormwater requirements and
those proposed for portions of High Point, Jamestown and Archdale would
be nearly as stringent as the Option B proposals. Although the
stormwater requirements in the Critical Areas around the lake are
generally equal to, and in some instances more stringent than, the
recommendations in Option B, in the remainder of the watershed, or the
Protected Areas, the density options would allow considerably more
development. For single family residences, the rules now in place or
proposed for the Protected Areas would generally allow at least twice
the single family residence densities than in the Option B proposals.
Although much of the land in the protected areas is now limited to one
house per acre (12%), as is recommended in the Option B proposal, this
limit will be allowed to increased to two houses per acre or (24%) once
sewer service is provided. (See Appendix A, page _ for chart on
densities.) Also, in all the protected areas in the lower watershed,
except Randolph County, up to 70% impervious are coverage is allowed if
stormwater controls are in place. This allows greater densities than
are proposed in Option B (50% maximum in Protected Areas). Because of
the expectation that much of the watershed will eventually be sewered,
and the greater densities allowed, the hearing officers have recommended
i
that the Option B stormwater proposals remain as the recommendation for
the final rule.
SUMMARY OF MAJOR COMMENTS AND STAFF RESPONSES
Comment: Allow construction of the reservoir with the management
strategy recommended in Option A.
Response: Of the comments received during this process, approximately
45% noted a desire for the EMC to proceed with the reclassification
action along the lines proposed as the Option A recommendation. Most
noted that Greensboro has severe short and long-term needs for
additional water sources, that enough time and money had been spent
studying this source, and that it was not appropriate to place controls
on the affected governments more stringent than are being applied in
other water supplies in the state.
Comment: Require very stringent point and nonpoint source controls as
outlined in Option B.
Approximately 55% of those providing comments indicated either a desire
to require stringent point and nonpoint source controls as suggested in
Option B or to deny the classification as a water supply source. The
recommendation for the full Commission is a combination of the point and
nonpoint source controls in Option A and Option B.
Comment: Do not require moving the discharge pipe from the High Point
Eastside WWTP downstream to a location below the Dam.
Response: The proposal to move the discharge of the High Point Eastside
WWTP to a location below the dam did not receive much support. The
option was included because it would be a means of substantially
reducing the predicted chlorophyll a violations in the Deep River
Segment I. (See map in Appendix B, page _.) However, many comments
were provided indicating opposition to moving the discharge. Many cited
the need to use the reservoir to remove pollutants from the High Point
Eastside discharge and in so doing, to reduce the impact on the quality
of the downstream river. Resolutions opposing the movement of the
discharge were received from the following:
Town of Angier
Lower Cape Fear Water and Sewer Authority
Randolph County Board of Commissioners
City of Archdale
City of Randleman
Town of Jamestown
Piedmont Triad Regional Water Authority
City of Asheboro
Town of Sanford
New Hanover County Board of Commissioners
Town of Lillington
Seagrove/Ulah MSD
Harriet County Board of Commissioners
Randolph County Chamber of Commerce
Town of Franklinville
City of Trinity
Town of Ranseur
Town of Liberty
Town of Seagrove
Town of Erwin
In light of the resolutions and comments received, and other
information available, the staff and the hearing officers are
recommending not pursuing this alternative.
Comment: Predicted lake eutrophication will result in a problem for the
water supply.
Response: Although existing models have predicted that certain areas of
the lake may see violations of the chlorophyll a standard during some of
the growing season, the staff has concluded that, based on the
predictive models, the requirement that the uses of the lake will be
supported will be met and the lake will be an acceptable source for a
water supply. The recommended management strategy will include
provisions that point source phosphorus levels from the High Point
Eastside WWTP will be set at 0.5 mg/1, provided the discharge is
relocated approximately 1.5 miles downstream to a point in the lake
below the Division's Deep River Segment 1. The nonpoint source
requirements also include provisions for densities and buffer
requirements greater than what is required for other water supplies in
the state. Also, the provisions placed in the rule which will mandate
additional controls if unacceptable water quality conditions occur will
help assure the long-term quality of the lake.
10/19/98 12:04 PM
Comment: The quality of the proposed lake will be similar to, or
possibly better than, what we are now seeing in other Piedmont
reservoirs, and therefore, no additional requirements are warranted.
Response: Proponents of the reservoir point out that the predicted
chlorophyll a violations, averaged over the entire lake, would be within
limits and would be better than Falls and Jordan Lakes are now.
However, under certain effluent conditions (0.5 mg/1), models predict
that in the Deep River Segment I arm of the lake, there is a potential
for chlorophyll a levels to occur that would be greater than those now
seen at the above two lakes. At full capacity of the High Point
Eastside WWTP, and at 25-year build-out development impacts, the
predicted chlorophyll a violations would be in the 80% range. This
compares to the violation frequency in the upper arms of the Falls and
Jordan Reservoirs in the 40% range. (Please note that this is existing
and would be expected to rise as development occurs upstream during the
next 25 years.) Although some exceedences of the 40 ug/l standard occur
now in the Deep River and are expected in the future reservoir as well,
this level of exceedence would not be considered acceptable.
Comment: Other sources of water are available for the region.
Response: Although the Division staff did not undertake a detailed,
independent analysis of the potential to use other water sources to
supply the needs of the PTRWA (Piedmont Triad Regional Water Authority),
it did review existing information and concluded that, although there
were other sources of water that could be used, this source appeared to
best meet the requirements of the Authority for a source. A 1985 CH2M
Hill report evaluated 40 alternatives that could be used as sources of
water for the region. These alternatives included: purchasing water
from the City of Burlington, from Lake Jordan, from Winston-Salem, from
Lake Reese, from Reidsville, using the Dan River, the Mayo, the Haw,
groundwater, combinations of these and many others. Although most
provided an inadequate safe yield for the long-term needs of the
Authority, some would provide the volume necessary. However, with each
source, there were some problems such as interbasin transfer issues,
excessive costs of the resultant supplies, or serious legal, political,
or environmental hurdles. In addition, it was noted at an EMC meeting
that the action of reclassification did not mandate the Commission
making a determination if this was the best source of water for the
Authority but only to make a decision as to its suitability as a source
and whether it should be accordingly reclassified.
Comment: The proposed point source control requirements on High Point
are unachievable.
Response: Discussions with other states indicate there are several
facilities in this country who are meeting levels of phosphorus removal
at or below the 0.18 mg/1 level that was proposed for the High Point
East Side facility, if the discharge were to remain at its present
location. However, if the discharge is moved, it appears from the
models that a limit of 0.5 mg/l phosphorus will provide adequate
protection to enable reclassification to occur.
Comment: The costs of achieving extremely low phosphorus levels at the
High Point facility are not in proportion to the benefits achieved.
Response: If the discharge from High Point Eastside WWTP were to remain
in the Deep River segment I, meeting a 0.5 mg/l phosphorus level at the
High Point East Side WWTP would still constitute over 45% of the
phosphorus entering the basin on a yearly basis and, according to
models, would result in unacceptable levels of chlorophyll a
excursions. The staff and the hearing officers' recommendation, that
the discharge be moved downstream to a point below Deep River segment 1,
would enable the permits to be set at a 0.5 mg/1 rate rather than the
0.18 mg/l that was originally proposed.
Comment: The "lost opportunity" costs of requiring local governments to
restrict densities further than is now required in the Watershed
Protection Program is not justified.
Response: Projections of costs to local governments to implement the
Option B requirements have been in the area of 100 million dollar impact
for small local governments and over a billion for a larger government.
Although there will be some costs to local governments for these more
stringent densities, we believe the extremely large estimates have not
considered other factors associated with lower density development. A
major problem is that the estimates of costs provided the State did not
consider the costs to the local governments to provide services, such as
sewerage, schools, and police and fire protection. The net costs to
local governments would be considerably lower than earlier projections.
It is further noted that local governments in North Carolina now
requiring similar densities have not reported the extreme values of lost
revenues.
Comment: The existing requirements for water supply watershed protection
are working in Oak Hollow and City Lake watersheds and Option B is not
needed.
Response: The DWQ believes that additional point and nonpoint source
controls are needed to address the potential eutrophic conditions
expected in the lake. The Division does not want to create a lake that
will soon be adversely affected by algal growth at eutrophic levels. In
the area of nonpoint source controls, the Division has urged the hearing
officers to seek the most conservative densities and buffer requirements
that are acceptable. They emphasized that correcting problems, after
the fact, that are caused, or influenced, by overly dense development or
loss of protective buffers is extremely costly, if it can be done at
all.
Comment: Local governments who initiated watershed protection programs
before the state requirements were developed should be given credit for
their early programs.
Response: Several local governments are to be commended for their
innovative programs, some of which were started over ten years ago. The
Division believes those programs have been instrumental in helping
control the problems seen in the existing reservoirs and has discussed
with the hearing officers ways to include those factors in their final
recommendations. However, the final requirements must be at a level to
insure that the quality of the future lake will be protected, although
the Commission has latitude to apply controls as they think appropriate.
Comment: The existing landfills and other waste sites will threaten the
lake's water quality to the extent that it would not be suitable as a
water supply source.
Response: The potential for contamination of the reservoir from the two
adjacent landfills has been an issue of concern to many. However,
because predictive modeling information available to the Division
indicates that the concentration of toxicants in drinking water obtained
from this lake will not result in any exceedences of state or federal
drinking water standards, the proposal does not include any additional
management recommendations for those landfills.
Comment: The classification schedule shown on page 19 of the information
package speaks as though the reclassification was "a done deal."
Response: Several comments were received indicating that the
classification schedule showed that the DWQ had already decided to
reclassify the lake as a source since it states that the "schedule of
classifications was amended effective April 1, 1999." According to
state rule-making requirements, the proposed rule changes must be
written as they would be adopted. Then the Commission would adopt,
modify, or take no action. We acknowledge that it is confusing but want
to emphasize that the intent was not to preclude any decision of the
Commission.
Comment: Because of the distance upstream and the existing Oak Hollow
and City Lake impoundments, the need for requiring additional controls
in the upper watershed is not as critical.
Response: The staff and the EMC hearing officers have considered the
role of the existing Oak Hollow and City Lake impoundments on reducing
the impact of additional nutrient nonpoint source runoff from those
watersheds, along with other factors such as the existing quality of
those lakes and the controls presently in place, in deciding whether to
apply additional density controls in the uppermost portion of the
Randleman watershed. The recommendation to the EMC will be to accept
the existing density controls now in place in those watersheds (above
Oakdale-Cotton Mill dam) rather than recommending a change. However,
the hearing officers are recommending that a "no disturb" buffer be
required in those watersheds as it recommended for the lower Randleman
Lake watershed.
Comment: There is no environmental benefit from moving the High Point
Eastside downstream from its present site.
Response: If the High Point Eastside discharge were to remain at its
present site and discharge at a 0.5 mg/l phosphorus level into the Deep
River Segment 1, the average chlorophyll a value expected in that arm of
the lake, during the growing season, would be 76 ug/l (with the Option B
NPS controls). Also, the models predict that the waters would violate
the 40 ug/1 chlorophyll a standard 80% of the time. The staff have
concluded that this level of eutrophication would result in an
unacceptable level of water quality in that arm of the lake. The models
predict that moving the discharge downstream approximately 1.5 miles
will result in an average chlorophyll a value in that Segment 1, during
the growing season, of 39 ug/1.
Comment: The City of High Point suggested that the rules require the
recording of the riparian protection areas only on new plats, not on
modified ones.
Response: The staff considered the potential problems with requiring
that riparian areas be recorded on both new and modified plats and
agreed that there is justification for only requiring recording of
riparian protection areas on new plats.
Comment: The City of High Point proposed that the density requirements
only apply to projects needing a sedimentation and erosion permit.
Response: The hearing officers have concurred with the staff position
that this reservoir is unique in its need for water quality protection.
They also support the position that all reasonable action be taken to
minimize the risk of substantial water quality problems occurring in the
developed lake. Although WS-IV's do not usually mandate that the
density rules apply except when a sedimentation erosion control permit
is required, WS-II and WS III watersheds require that they apply for all
development. Because the staff and hearing officers desire to take
every reasonable opportunity to apply a management strategy that will
reduce the nutrient loading to the reservoir, they concurred that this
requirement is appropriate.
Comment: Do not require the Authority to use both USGS and USDA maps and
create a new one based on DQW criteria.
Response: After reviewing the minimal potential for additional
protection of the lake's water quality, it was decided that using the
topo map and the soil survey maps to determine which streams would be
affected by the riparian protection requirements would be adequate.
However, because of comments received, the rule proposal was modified to
allow local governments to develop their own maps which, if approved by
the Division of Water Quality, could be used to enforce the riparian
area provisions of the rules in lieu of using the USGS and USDA maps.
Comment: High Point proposed using the- tonO" rule in the noncritical
area
Response: The 10/70 provision, which is available in other WS-IV water
supply watersheds, was intentionally left out of the proposed rules.
The "10/70" rule allows local governments who do not use the high
density option to allow 10% of the land in the watershed in their
jurisdiction to be developed at an impervious cover maximum of 70%. The
staff concluded that they did not want to encourage 70% impervious
coverage development in this watershed, especially when treatment of the
first inch of rainfall is not required in the rules. They also question
whether it would be used by any local governments in the watershed. The
recommendation is that this provision not be included in the lower
Randleman watershed, although where it exists in the upper watershed
local ordinances, it shall continue to be allowed as an option.
Comment: The City of High Point's comments suggested that rather than
use the USGS topo maps and USDA soil maps to define where perennial and
intermittent streams start, use an acreage number.
Response: The City recommended that 50 acres be used to define where a
stream exists. The DQW data for piedmont streams suggests that a
watershed of 20 acres might be appropriate. Some watersheds as low as
two or three acres produced viable streams. The staff did recommend
that local governments would be able to use other methods of defining
streams if those methods were approved by the Division as being
essentially equivalent in protection.
Comment: The City of High Point commented that "non residential
development is difficult to infeasible at 50% built-upon area."
Response: There are 99 watersheds in the state that are classified as WS
It or WS III. The maximum impervious area allowed in WS III watersheds,
using the high density option, is 30% in the critical area and 50% in
the remainder of the watershed. In WS It watersheds, the maximum
densities allowed are 24% and 30%. Other communities across the state
have been able to comply with these limitations. It is recognized that
the limitations will cause difficulties in some cases. Variance
provisions in the rules would allow opportunities for site-specific
consideration of some of these difficult situations. The recommendation
is to not modify the proposed maximum densities allowed.
Comment: Buffers should be around perennial streams only.
Response: In an article in the September/October 1998 EPA Nonpoint
Source Newsnotes, the author (Earl Shaver, Auckland Regional Council)
provided that: "If our goals include protection of instream resources,
we must provide more aggressive protection of first and second order
streams. Seventy-two percent of all waterways in the United States are
first or second order streams. We cannot hope to protect third order or
larger streams if we allow enclosure, channelization, or destruction of
first and second order ones. " Since allowing grading next to the
intermittent streams not only increases the potential that they will be
destroyed, the downstream segments, which eventually become perennial
streams, receive the sediment, nutrients, and other stormwater runoff
from those streams. Larger streams will not be protected without
protecting the upstream intermittent streams. The recommendation is
that the buffer be applied to all perennial and intermittent streams in
the entire Randleman watershed.
Comment: More buffer than 50 feet needed.
Response: Although more buffer is desirable, the hearing officers
considered the 50 ft. buffer requirement to be a very firm step toward
achieving water quality protection in the lake.
Comment 15 ft undisturbed buffer is ok.
Response: Some comments indicated that a reduction from the proposed 30
ft. undisturbed buffer to 15 ft. undisturbed buffer would be adequate
for the watershed. The hearing officers' desire is to keep the
undisturbed area of riparian protection at 30 ft.
Comment: Allow a reasonable amount of time for local governments to
complete the comprehensive stormwater planning effort.
Response: WORKING ON THIS ONE
Comment: The proposed rules would require all infrastructure stream
crossings to be approved by the EMC.
Response: Although it is not clearly stipulated in the rules who makes
these type of calls, unless it is stipulated that the EMC make the
decision, the Division Director or his designees will make them. It is
the intent of the hearing officers that these decisions are to be made
by the DWQ staff, unless a major variance is being requested.
Comment: The lakewide average chlorophyll a values are acceptable under
Option A management strategy.
Response: Some commenters suggested that since the models predicted that
the lakewide averages of chlorophyll a would be well below the 40 ug/1
standard, it was an inefficient use of funds to require the controls
specified in Option B. The staff pointed out that even though the
average value would be within the standards range, there will be
significant areas of the lake where the standards will be violated and
excessive algal growths will occur unless a more aggressive management
strategy is followed.
Comment: The state should not require controls in this lake more
stringent than in similar lakes.
Response: This lake is different from existing lakes because there is a
potential to create a segment of water that will not fully support its
uses - that is to create water quality problems where those problems do
not presently exist. The Division believes it should proceed with
caution and apply whatever controls are needed to minimize the potential
for more serious future problems.
Comment: Classify the waters as NSW.
Response: The Division had considered recommending reclassifying the
waters of the reservoir as Nutrient Sensitive Waters or NSW. However,
it was decided to not seek that classification since the affected
segments are being proposed as a "Critical water supply watershed." The
statutes give the Commission authority to "impose management
requirements that are more stringent than the minimum statewide water
supply watershed management requirements" in these watersheds. It was
concluded that adequate authorities were available to apply the controls
intended for the watershed and that going through the additional steps
to complete the NSW reclassification was not needed.
Comment: Allow construction of the reservoir with the management
strategy recommended in Option A.
Response: Of the comments received during this process, approximately
45% noted a desire for the EMC to proceed with the reclassification
action along the lines proposed as the Option A recommendation. Most
noted that Greensboro has severe short and long-term needs for
additional water sources, that enough time and money had been spent
studying this source, and that it was not appropriate to place controls
on the affected governments more stringent than are being applied in
other water supplies in the state.
Comment: Require very stringent point and nonpoint source controls as
outlined in Option B.
Approximately 55% of those providing comments indicated either a desire
to require stringent point and nonpoint source controls as suggested in
Option B or to deny the classification as a water supply source. The
recommendation for the full Commission is a combination of the point and
nonpoint source controls in Option A and Option B.
Comment: Do not require moving the discharge pipe from the High Point
Eastside WWTP downstream to a location below the Dam.
Response: The proposal to move the discharge of the High Point Eastside
WWTP to a location below the dam did not receive much support. The
option was included because it would be a means of substantially
reducing the predicted chlorophyll a violations in the Deep River
Segment I. (See map in Appendix B, page _.) However, many comments
were provided indicating opposition to moving the discharge. Many cited
the need to use the reservoir to remove pollutants from the High Point
Eastside discharge and in so doing, to reduce the impact on the quality
of the downstream river. Resolutions opposing the movement of the
discharge were received from the following:
Town of Angier
Lower Cape Fear Water and Sewer Authority
Randolph County Board of Commissioners
City of Archdale
City of Randleman
Town of Jamestown
Piedmont Triad Regional Water Authority
City of Asheboro
Town of Sanford
New Hanover County Board of Commissioners
Town of Lillington
Seagrove/Ulah MSD
Harnet County Board of Commissioners
Randolph County Chamber of Commerce
Town of Franklinville
City of Trinity
Town of Ranseur
Town of Liberty
Town of Seagrove
Town of Erwin
In light of the resolutions and comments received, and other
information available, the staff and the hearing officers are
recommending not pursuing this alternative.
Comment: Predicted lake eutrophication will result in a problem for the
water supply.
Response: Although existing models have predicted that certain areas of
the lake may see violations of the chlorophyll a standard during some of
the growing season, the staff has concluded that, based on the
predictive models, the requirement that the uses of the lake will be
supported will be met and the lake will be an acceptable source for a
water supply. The recommended management strategy will include
provisions that point source phosphorus levels from the High Point
Eastside WWTP will be set at 0.5 mg/1, provided the discharge is
relocated approximately 1.5 miles downstream to a point in the lake
below the Division's Deep River Segment 1. The nonpoint source
requirements also include provisions for densities and buffer
requirements greater than what is required for other water supplies in
the state. Also, the provisions placed in the rule which will mandate
additional controls if unacceptable water quality conditions occur will
help assure the long-term quality of the lake.
10/19/98 12:04 PM
Comment: The quality of the proposed lake will be similar to, or
possibly better than, what we are now seeing in other Piedmont
reservoirs, and therefore, no additional requirements are warranted.
Response: Proponents of the reservoir point out that the predicted
chlorophyll a violations, averaged over the entire lake, would be within
limits and would be better than Falls and Jordan Lakes are now.
However, under certain effluent conditions (0.5 mg/1), models predict
that in the Deep River Segment I arm of the lake, there is a potential
for chlorophyll a levels to occur that would be greater than those now
seen at the above two lakes. At full capacity of the High Point
Eastside WWTP, and at 25-year build-out development impacts, the
predicted chlorophyll a violations would be in the 80% range. This
compares to the violation frequency in the upper arms of the Falls and
Jordan Reservoirs in the 40% range. (Please note that this is existing
and would be expected to rise as development occurs upstream during the
next 25 years.) Although some exceedences of the 40 ug/I standard occur
now in the Deep River and are expected in the future reservoir as well,
this level of exceedence would not be considered acceptable.
Comment: Other sources of water are available for the region.
Response: Although the Division staff did not undertake a detailed,
independent analysis of the potential to use other water sources to
supply the needs of the PTRWA (Piedmont Triad Regional Water Authority),
it did review existing information and concluded that, although there
were other sources of water that could be used, this source appeared to
best meet the requirements of the Authority for a source. A 1985 CH2M
Hill report evaluated 40 alternatives that could be used as sources of
water for the region. These alternatives included: purchasing water
from the City of Burlington, from Lake Jordan, from Winston-Salem, from
Lake Reese, from Reidsville, using the Dan River, the Mayo, the Haw,
groundwater, combinations of these and many others. Although most
provided an inadequate safe yield for the long-term needs of the
Authority, some would provide the volume necessary. However, with each
source, there were some problems such as interbasin transfer issues,
excessive costs of the resultant supplies, or serious legal, political,
or environmental hurdles. In addition, it was noted at an EMC meeting
that the action of reclassification did not mandate the Commission
making a determination if this was the best source of water for the
Authority but only to make a decision as to its suitability as a source
and whether it should be accordingly reclassified.
Comment: The proposed point source control requirements on High Point
are unachievable.
Response: Discussions with other states indicate there are several
facilities in this country who are meeting levels of phosphorus removal
at or below the 0.18 mg/1 level that was proposed for the High Point
East Side facility, if the discharge were to remain at its present
location. However, if the discharge is moved, it appears from the
models that a limit of 0.5 mg/1 phosphorus will provide adequate
protection to enable reclassification to occur.
Comment: The costs of achieving extremely low phosphorus levels at the
High Point facility are not in proportion to the benefits achieved.
Response: If the discharge from High Point Eastside WWTP were to remain
in the Deep River segment I, meeting a 0.5 mg/1 phosphorus level at the
High Point East Side WWTP would still constitute over 45% of the
phosphorus entering the basin on a yearly basis and, according to
models, would result in unacceptable levels of chlorophyll a
excursions. The staff and the hearing officers' recommendation, that
the discharge be moved downstream to a point below Deep River segment 1,
would enable the permits to be set at a 0.5 mg/1 rate rather than the
0.18 mg/1 that was originally proposed.
Comment: The "lost opportunity" costs of requiring local governments to
restrict densities further than is now required in the Watershed
Protection Program is not justified.
Response: Projections of costs to local governments to implement the
Option B requirements have been in the area of 100 million dollar impact
for small local governments and over a billion for a larger government.
Although there will be some costs to local governments for these more
stringent densities, we believe the extremely large estimates have not
considered other factors associated with lower density development. A
major problem is that the estimates of costs provided the State did not
consider the costs to the local governments to provide services, such as
sewerage, schools, and police and fire protection. The net costs to
local governments would be considerably lower than earlier projections.
It is further noted that local governments in North Carolina now
requiring similar densities have not reported the extreme values of lost
revenues.
Comment: The existing requirements for water supply watershed protection
are working in Oak Hollow and City Lake watersheds and Option B is not
needed.
Response: The DWQ believes that additional point and nonpoint source
controls are needed to address the potential eutrophic conditions
expected in the lake. The Division does not want to create a lake that
will soon be adversely affected by algal growth at eutrophic levels. In
the area of nonpoint source controls, the Division has urged the hearing
officers to seek the most conservative densities and buffer requirements
that are acceptable. They emphasized that correcting problems, after
the fact, that are caused, or influenced, by overly dense development or
loss of protective buffers is extremely costly, if it can be done at
all.
Comment: Local governments who initiated watershed protection programs
before the state requirements were developed should be given credit for
their early programs.
Response: Several local governments are to be commended for their
innovative programs, some of which were started over ten years ago. The
Division believes those programs have been instrumental in helping
control the problems seen in the existing reservoirs and has discussed
with the hearing officers ways to include those factors in their final
recommendations. However, the final requirements must be at a level to
insure that the quality of the future lake will be protected, although
the Commission has latitude to apply controls as they think appropriate.
Comment: The existing landfills and other waste sites will threaten the
lake's water quality to the extent that it would not be suitable as a
water supply source.
Response: The potential for contamination of the reservoir from the two
adjacent landfills has been an issue of concern to many. However,
because predictive modeling information available to the Division
indicates that the concentration of toxicants in drinking water obtained
from this lake will not result in any exceedences of state or federal
drinking water standards, the proposal does not include any additional
management recommendations for those landfills.
Comment: The classification schedule shown on page 19 of the information
package speaks as though the reclassification was "a done deal."
Response: Several comments were received indicating that the
classification schedule showed that the DWQ had already decided to
reclassify the lake as a source since it states that the "schedule of
classifications was amended effective April 1, 1999." According to
state rule-making requirements, the proposed rule changes must be
written as they would be adopted. Then the Commission would adopt,
modify, or take no action. We acknowledge that it is confusing but want
to emphasize that the intent was not to preclude any decision of the
Commission.
Comment: Because of the distance upstream and the existing Oak Hollow
and City Lake impoundments, the need for requiring additional controls
in the upper watershed is not as critical.
Response: The staff and the EMC hearing officers have considered the
role of the existing Oak Hollow and City Lake impoundments on reducing
the impact of additional nutrient nonpoint source runoff from those
watersheds, along with other factors such as the existing quality of
those lakes and the controls presently in place, in deciding whether to
apply additional density controls in the uppermost portion of the
Randleman watershed. The recommendation to the EMC will be to accept
the existing density controls now in place in those watersheds (above
Oakdale-Cotton Mill dam) rather than recommending a change. However,
the hearing officers are recommending that a "no disturb" buffer be
required in those watersheds as it recommended for the lower Randleman
Lake watershed.
Comment: There is no environmental benefit from moving the High Point
Eastside downstream from its present site.
Response: If the High Point Eastside discharge were to remain at its
present site and discharge at a 0.5 mg/1 phosphorus level into the Deep
River Segment I, the average chlorophyll a value expected in that arm of
the lake, during the growing season, would be 76 ug/l (with the Option B
NPS controls). Also, the models predict that the waters would violate
the 40 ug/l chlorophyll a standard 80% of the time. The staff have
concluded that this level of eutrophication would result in an
unacceptable level of water quality in that arm of the lake. The models
predict that moving the discharge downstream approximately 1.5 miles
will result in an average chlorophyll a value in that Segment 1, during
the growing season, of 39 ug/1.
Comment: The City of High Point suggested that the rules require the
recording of the riparian protection areas only on new plats, not on
modified ones.
Response: The staff considered the potential problems with requiring
that riparian areas be recorded on both new and modified plats and
agreed that there is justification for only requiring recording of
riparian protection areas on new plats.
Comment: The City of High Point proposed that the density requirements
only apply to projects needing a sedimentation and erosion permit.
Response: The hearing officers have concurred with the staff position
that this reservoir is unique in its need for water quality protection.
They also support the position that all reasonable action be taken to
minimize the risk of substantial water quality problems occurring in the
developed lake. Although WS-IV's do not usually mandate that the
density rules apply except when a sedimentation erosion control permit
is required, WS-II and WS III watersheds require that they apply for all
development. Because the staff and hearing officers desire to take
every reasonable opportunity to apply a management strategy that will
reduce the nutrient loading to the reservoir, they concurred that this
requirement is appropriate.
Comment: Do not require the Authority to use both USGS and USDA maps and
create a new one based on DQW criteria.
Response: After reviewing the minimal potential for additional
protection of the lake's water quality, it was decided that using the
topo map and the soil survey maps to determine which streams would be
affected by the riparian protection requirements would be adequate.
However, because of comments received, the rule proposal was modified to
allow local governments to develop their own maps which, if approved by
the Division of Water Quality, could be used to enforce the riparian
area provisions of the rules in lieu of using the USGS and USDA maps.
Comment: High Point proposed using the "10/70" rule in the noncritical
area
Response: The 10/70 provision, which is available in other WS-IV water
supply watersheds, was intentionally left out of the proposed rules.
The "10/70" rule allows local governments who do not use the high
density option to allow 10% of the land in the watershed in their
jurisdiction to be developed at an impervious cover maximum of 70%. The
staff concluded that they did not want to encourage 70% impervious
coverage development in this watershed, especially when treatment of the
first inch of rainfall is not required in the rules. They also question
whether it would be used by any local governments in the watershed. The
recommendation is that this provision not be included in the lower
Randleman watershed, although where it exists in the upper watershed
local ordinances, it shall continue to be allowed as an option.
Comment: The City of High Point's comments suggested that rather than
use the USGS topo maps and USDA soil maps to define where perennial and
intermittent streams start, use an acreage number.
Response: The City recommended that 50 acres be used to define where a
stream exists. The DQW data for piedmont streams suggests that a
watershed of 20 acres might be appropriate. Some watersheds as low as
two or three acres produced viable streams. The staff did recommend
that local governments would be able to use other methods of defining
streams if those methods were approved by the Division as being
essentially equivalent in protection.
Comment: The City of High Point commented that "non residential
development is difficult to infeasible at 50% built-upon area."
Response: There are 99 watersheds in the state that are classified as WS
II or WS III. The maximum impervious area allowed in WS III watersheds,
using the high density option, is 30% in the critical area and 50% in
the remainder of the watershed. In WS II watersheds, the maximum
densities allowed are 24% and 30%. Other communities across the state
have been able to comply with these limitations. It is recognized that
the limitations will cause difficulties in some cases. Variance
provisions in the rules would allow opportunities for site-specific
consideration of some of these difficult situations. The recommendation
is to not modify the proposed maximum densities allowed.
Comment: Buffers should be around perennial streams only.
Response: In an article in the September/October 1998 EPA Nonpoint
Source Newsnotes, the author (Earl Shaver, Auckland Regional Council)
provided that: "If our goals include protection of instream resources,
we must provide more aggressive protection of first and second order
streams. Seventy-two percent of all waterways in the United States are
first or second order streams. We cannot hope to protect third order or
larger streams if we allow enclosure, channelization, or destruction of
first and second order ones. " Since allowing grading next to the
intermittent streams not only increases the potential that they will be
destroyed, the downstream segments, which eventually become perennial
streams, receive the sediment, nutrients, and other stormwater runoff
from those streams. Larger streams will not be protected without
protecting the upstream intermittent streams. The recommendation is
that the buffer be applied to all perennial and intermittent streams in
the entire Randleman watershed.
Comment: More buffer than 50 feet needed.
Response: Although more buffer is desirable, the hearing officers
considered the 50 ft. buffer requirement to be a very firm step toward
achieving water quality protection in the lake.
Comment 15 ft undisturbed buffer is ok.
Response: Some comments indicated that a reduction from the proposed 30
ft. undisturbed buffer to 15 ft. undisturbed buffer would be adequate
for the watershed. The hearing officers' desire is to keep the
undisturbed area of riparian protection at 30 ft.
Comment: Allow a reasonable amount of time for local governments to
complete the comprehensive stormwater planning effort.
Response: WORKING ON THIS ONE
Comment: The proposed rules ;vould require all infrastructure stream
crossings to be approved by the EMC.
Response: Although it is not clearly stipulated in the rules who makes
these type of calls, unless it is stipulated that the EMC make the
decision, the Division Director or his designees will make them. It is
the intent of the hearing officers that these decisions are to be made
by the DWQ staff. unless a major variance is being requested.
Comment: The lakewide average chlorophyll a values are acceptable under
Option A management strategy.
Response: Some commenters suggested that since the models predicted that
the lakewide averages of chlorophyll a would be well below the 40 ug/I
standard, it was an inefficient use of funds to require the controls
specified in Option B. The staff pointed out that even though the
average value would be within the standards range, there will be
significant areas of the lake where the standards will be violated and
excessive algal growths will occur unless a more aggressive management
strategy is followed.
Comment: The state should not require controls in this lake more
stringent than in similar lakes.
Response: This lake is different from existing lakes because there is a
potential to create a segment of water that will not fully support its
uses - that is to create water quality problems where those problems do
not presently exist. The Division believes it should proceed with
caution and apply whatever controls are needed to minimize the potential
for more serious future problems.
Comment: Classify the waters as NSW.
Response: The Division had considered recommending reclassifying the
waters of the reservoir as Nutrient Sensitive Waters or NSW. However,
it was decided to not seek that classification since the affected
segments are being proposed as a "Critical water supply watershed." The
statutes give the Commission authority to "impose management
requirements that are more stringent than the minimum statewide water
supply watershed management requirements" in these watersheds. It was
concluded that adequate authorities were available to apply the controls
intended for the watershed and that going through the additional steps
to complete the NSW reclassification was not needed.
Regional Water Authority, about the potential quality of the reservoir.
Much of the discussion focused on the potential for contamination of the
reservoir from the two adjacent landfills. There have also been
comments given about other waste sites in the basin and concerns voiced
about data available which showed toxic chemicals in the Deep River
which might contaminate the quality of the reservoir. Fortunately, the
measured quality in the river has improved from earlier investigations
made by the Division and the levels of potentially toxic chemicals have
not been such that a threat to the suitability of the reservoir as a
source of water supply has been seen. The staff and the hearing
officers reviewed information provided by the Authority in their
"Randleman Lake Nutrient Reduction Strategy and Implementation Plan"
(Draft version - March 1998) in reaching their recommendation on
reclassification. Section 3 of that document provides a summary of an
analyses made by Tetra Tech, Inc. and was particularly useful in helping
the staff and the hearing officers develop an opinion on the suitability
of the source for water supply purposes. (Copy of Section 3 is included
in Appendix A, page _.) The article addressed four major areas of
concern regarding the potential contamination of the source: 1)
concentrations of lindane in High Point WWTP effluent, 2) potential
leaching of chemicals from the Seaboard/Riverdale Landfill site, 3)
concentrations of phenolics seen in the Deep River, and 4) unidentified
organic chemicals in DWQ analyses of the Deep River. The work done by
Tetra Tech concluded, and the staff and hearing officers agreed, that
based on the level of pollutants observed and the conservative nature of
the models used, the information available does not indicate the
existence of any significant potential threat to the quality necessary
for a WS-IV water supply.
MAINTENANCE OF RIPARIAN AND BUFFER AREAS
The Water Quality Section staff recommended that, in addition to the
statewide water supply watershed requirements to maintain a vegetated
(or revegetated) buffer around perennial streams, the buffers in the
Randleman watershed should include protection of a riparian zone where
only limited disturbances are allowed in the existing flora. They also
recommended that the enhanced riparian area protection requirements be
applied not only around perennial streams but also around intermittent
streams. The proposal that was sent to public hearing contained in
Option B the requirement that a buffer be applied similar to that
applied by the Commission in the Neuse River. The proposal was for a 30
foot "no-disturbance" zone adjacent to the streams and a 20 foot area
adjacent to that zone where limited tree or fruit crop harvesting could
occur. (Other specified land disturbing activities could occur when
special needs exists or hardships were encountered.)
The proposals were based on an understanding by the staff that in order
to protect larger streams and lakes from severe degradation, the
Division's program must be more aggressive in protecting first and
second order streams. The staff firmly believe that it is essential to
protect these perennial anephemeral streams from mass grading,
channelization, enclosing in pipes,? and other activities which
significantly increase flow volumes, velocities and erosion potential
along with nutrient and sediment contribution. Phosphorus is
particularly vulnerable to these types of stream destruction practices
l
Because the alternative downstream discharge location (at Freeman Mill)
significantly affects the predictions of eutrophication levels in Deep
River Segment 1, the hearing officers further expanded their evaluations
on this alternative. The City of High Point commented that relocating
the discharge would cost around $10,000,000 and that the environmental
benefits would not justify that expenditure. They proposed that the
effluent level be set at 0.5 mg/l, based on a quarterly average, and
that the discharge remain in Segment 1 of the lake, where it is now
located. They noted that the average chlorophyll a predictions in
downstream arms of the lake would be minimally affected by having the
discharge in Segment 1. (See Appendix A, pages _ and _.) The
hearing officers considered this information in reaching a decision but
have concluded that, in their opinion, the benefits of keeping the
predicted chlorophyll a values in segment 1 at the lower levels did
justify the anticipated cost of relocating the discharge. Their
recommendation is that the Division Director require that the permit
given High Point include stipulations that the discharge be relocated
downstream to a point near Freeman Mill and into Segment 2 of the lake.
The City of High Point recommended in their comments that a phosphorus
limit of 0.5 mg/1 be applied (at the existing site) but on a quarterly
average. The DWQ staff noted that many facilities in the state are
meeting the 0.5 mg/l phosphorus average and that there is no overriding
justification to allow the City of High Point any special exemption from
this requirement.
The initial proposal that went out to hearing included provisions for a
mass (poundage) limitation of phosphorus that could be discharged at the
High Point Facility at the design flow of 26 MGD. The mass limit was
calculated by multiplying the 26 MGD flow times the concentration at
0.18 mg/1. The total permitted load would be 14,200 lb/yr. However, if
the discharge location were moved, the hearing officers would recommend
that the permit contain a total permitted load of 39,540 pounds per
year. This volume is based on the 0.5 mg/l concentration. The hearing
officers wanted it made clear that no more additional phosphorus over
this amount should enter the lake from point sources unless the
Commission was involved in the decision.
On the other hand, the hearing officers wanted to make it clear that,
based on the analyses provided them, these point source limitations,
combined with their recommended nonpoint source control requirements,
should result in a lake that will support all designated uses assigned
and that the reclassification action of the Commission would be
consistent with the requirements of the Federal Clean Water Act and the
State's laws and rules.
Although the recommendations in the proposed rules provide that the
point source limitations be adopted in rule, it is the staff's and the
hearing officers' recommendation that the rules recommended to the full
Commission do not specify point source limitations. There are several
reasons that led to this conclusion. Probably the most significant one
is that having specific point source limits in a permit make future
permitting changes extremely difficult. Because of the 1-2 year length
of time now required for rulemaking in this state, if the Division were
to see a need to modify the limitations in phosphorus levels in High
Points permit, either up or down, the staff would be facing a lengthy,
cumbersome process to get that accomplished. It is possible, for
example, that the lake does not behave as was predicted in models in
1998. Making changes in those permit limitations would not be easy.
Therefore, the final proposed rules do not include the permit limits for
the High Point East Side WWTP. However, the conclusions of this report
are to be used by the Director in preparing the NPDES permit for the
expanded High Point WWTP discharge.
Other discharges in the basin
The hearing officers agreed to maintain the prohibition on new or
expanded discharges of phosphorus-containing waste to the entire
Randleman basin, except for the expansions at the High Point Eastside
WWTP. This means that the few small discharges in the basin will not be
able to expand over their existing permit limits in the amount of
phosphorus they contribute. They can expand, although their expanded
permit must contain equal to or less than existing mass loading of
phosphorus.
NUTRIENT SENSITIVE WATERS CLASSIFICATION
The draft rules that went to public hearing recommended reclassifying ^ S
the waters of the reservoir as Nutrient Sensitive Waters or NSW. \ j
However, the staff and the hearing officers decided to recommend that V_* M
that classification be applied at this time. The most important reason
was that since the affected segments are being proposed as a "Critical
water supply watershed", any additional authority gained by documenting
conditions for NSW classification would not be needed. The statutes
give the Commission authority to "impose management requirements that
are more stringent than the minimum statewide water supply watershed
management requirements" in these watersheds.
d W

SUITABILITY OF THE WATERS AS A WATER SUPPLY
The Environmental Management Commission rules codified in 15A NCAC 2B
.0104(d) provide that "In considering the reclassification of waters for
water supply purposes, the Commission shall take into consideration the
relative proximity, quantity, composition, natural dilution and
diminution of potential sources of pollution to determine that risks
posed by all significant pollutants are adequately considered." They
also require in 15A NCAC 2B .0216(2) that "The waters, following
treatment required by the Division of Environmental Health, shall meet
the Maximum Contaminant Level concentrations considered safe for
drinking, culinary, or food-processing purposes which are specified in
the national drinking water regulations and in the North Carolina Rules
Governing Public Water Supplies, 15A NCAC 18C .1500. Sources of
pollution which preclude any of these uses on either a short-term or
long-term basis shall be considered to be violating a water quality
standard.
There has been considerable comment, especially in the previous
discussions regarding the decision of the Environmental Management
Commission to grant Eminent Domain authority to the Piedmont Triad
P F
Incoming Message
High Point Meeting on 7/7
Ag ?? )
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Subject: High Point Meeting on 7/7
Sent: 7/8/97 5:25 PM
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larry ausley, [e-mail]
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Wayne [e-mail]
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For all of you who could make it to the meeting yesterday - thank
you again for participating. The meeting was very informative for me
and I hope it was for all of you. If you could not make the meeting
yesterday, I hope the following is a good summary. Below, after the
minutes, I have included the results of the research into the status of
the EIS. I have also included a discussion of where we are going from
here. Please call me at [phone], ext 567 if you have any
questions.
High Point WWTP EA Meeting -
Draft Minutes
7/7/97
13th floor conf. room
10:00 am
Attending -
Michelle Suverkrubbe - WQ Planning
Jay Sauber - WQ Lab (ESB)
Larry Ausley - WQ Lab (ESB)
Kurt Trumbower - WQ Lab (ESB)
Owen Anderson - Wildlife Res. Comm.
Lee Spencer - DEH (public water)
Steve Zoufaly - WQ Planning
Alan Clark - WQ Planning
Jason Doll - WQ/ TSB (Instream Assessment)
Larry Coble - WQ WSRO
Lisa Martin - WQ (Operations/ Water Supply Watershed Protection)
Wayne Munden - DEH (water supply)
Coleen Sullins - WQ/ TSB (Permits & Engineering)
As we discussed yesterday, the water quality issues in the Deep River
below the WWTP and the proposed Randleman Lake are complicated,
to say the least. The purpose of the meeting was to figure out how to
proceed on the EA (i.e. let go, require more studies, require EIS) in
light of the water quality issues involved with the project (e.g.
existing WQ in river, projected WQ in proposed lake, contribution of
It
Incoming Message High Point Meeting on 7/7 Page 2 of 5
additional loads from both the proposed WWTP expansion and NPS
pollutants from stormwater).
In discussing the WWTP EA, a variety of issues were brought up at
the meeting, a summary of which follows -
1. The local governments that are located in the Randleman Lake
Watershed that are currently enforcing water supply watershed
ordinances include Guilford County, Greensboro, & Randolph County.
Other jurisdictions located in this proposed Randleman lake
watershed area that DO NOT currently protect for stormwater include
High Point, Jamestown, Archdale and Randleman.
2. The jurisdictions that will be served by the proposed WWTP
expansion include Guilford County, Forsyth County, High Point,
Jamestown and Archdale. Obviously, High Point, Jamestown and
Archdale will be served by the WWTP but do not currently protect
for stormwater under WSWS reg's. What, if anything can we make
them do to protect from NPS impacts of project?
3. Jay Sauber reported that WQ studies have shown that nutrient
levels in the main stem of the Deep River and Muddy Creek (where
the lake is proposed) are currently very high. If it was a lake, it
would for sure be eutrophic. A consultant for ESB ran a model on the
lake's WQ, and the algal growth potential for the lake reached new
records. With a 5 mg/l threshold for algal biomass as the threshold,
the model showed the creek at 25 mg/1 and the river at 277 mg/1.
Total Nitrogen was measured in 1994/95 to be 12 mg/1 average,
while Total Phosphorous was greater than 3 mg/1. The question was
reaised whether or not the proposed treatment plant improvements
would be reduced enough to allow this system to go from a river to a
lake and still meet WQ stds. Jay indicated that the river currently
violates stds. and no matter what happens with the WWTP, the
proposed lake will violate WWTP stds. `
Alan Clark asked about the retention time in the lake- Jay reported
that the model predicted that it was quite large.
It was asked if the limits for the WWTP will protect WQ Stds. Jay
requested that when DWQ permits the WWTP, we make it clear that
the water quality predicted for the lake violates WQ stds, so that we
are not blamed for the condition of the lake and we are not asked to
try to fix it once it is impounded. Another option was to set effluent
limits for the WWTP that assure that WQ stds will be met. Jason
indicated that spec. limits are not written to guarantee a clean bill of
health. DWQ should recognize the WQ problems in our
communications on this and mention the type and cost of technology
that would be necessary to treat the water in the lake for public use.
Coleen asked Jason to re-evaluate the speculative analysis and waste
load allocation model on the WWTP to see if the limits for the WWTP
will protect WQ stds.
Larry Coble felt that we should build mitigation into the WWTP
project in order to get assurances of WQ protections, from point and
non-point sources.
Larry Ausley asked how we know the lake is an inevitable project.
Several staff discussed the politics of the situation. Wayne Munden
talked about how the local governments in the area desperately need
the Randleman Lake water supply. He realizes that there will be WQ
problems there irregardless of the dam.
Incoming Message High Point Meeting on 7/7 Page 3 of 5
4. Lee Spencer talked about the technology that would be required
by the water treatment plant -- GAC (activated carbon) or membrane
filters and possibly auxillary treatment lagoons -- for treating this
water. He also mentioned that he has heard that a consultant (Hazen
& Sawyer?) is working on the EA for the water treatment plant for
the Lake. No one in attendance has heard anything on that project to
date.
5. A question was asked regarding High Point's committment to
reduction in I/I. Larry Coble responded that they have done some
work, but they have discovered it was cheaper to treat it than correct
it.
6. In discussing what to do about the indirect / NPS impacts from
this project, Coleen commented that all the WQ issues have not yet
been resolved. Several staff felt that there should have been one EIS
(not several EAs and EISs) which looked at all the inter-related WQ
issues for the entire project, from the construction of the dam and
loss of wildlife and wetlands, to the interbasin transfers and eminant
domain issues, to the WWTP expansion and water treatment plant
construction. As it stands now, staff feels that the wq issues have
sort of "fallen through the cracks" and not yet been addressed
adequately in any of the studies out there. Several staff (including
Coleen Sullins) requested that the EA address the nutrient loadings
anticipated from the treatment plant (as proposed to be improved)
vs. anticipated loads from development.
7. There was a lot of discussion about the EIS that was prepared by
DWR in 1991 on the eminant domain and the interbasin transfer
aspects of the Lake. That EIS "addressed all the WQ issues involved
with the Lake", according to the Army Corps of Engineers. The new
EIS (due out this week on the Lake by the Corps) supposedly will only
address wetlands and the 404 permit.
The consensus of the group was for me to research into the status
this EIS and report back to the group. If the EIS still is good
not been over-turned) then the question becomes - should DWQ ask
for a new evaluation of water quality in the WWTP EA or should we
ask for an EIS, since signing a FONSI will require giving them a
finding that no significant impacts to WQ will occur? If the EIS
rejected by the court case, then it should be expected that the
Randleman Lake EIS should address these WQ issues.
The meeting was adjourned at 11:30 AM.
Results of EIS research --
of
(i.e. has
was
After speaking with Melba McGee (DEHNR SEPA coordinator), John
Sutherland (DWR), and Frank Crawley (EMC atty.), I found out that in
fact the EIS (as it stands now), IS STILL VALID and HAS NOT BEEN
OVER-TURNED.
What happened was this -
In May, 1994 - Wake Superior Court responded to a petition by the
Deep River Citizens Coalition for a judicial review of the decision of
the EMC to approve the EIS (dated 1991/ prepared by DWR) and
approve eminent domain and interbasin transfer certificate for the
Randleman Lake project (constructing dam and using water for public
Incoming Message High Point Meeting on 7/7 Page 4 of 5
consumption). The Judge, basing his decision primarily on DEHNR's
hearing officer's report (which recommended that due to water
quality problems, the Randleman Lake project NOT be certified),
overturned the EMC's decision due to several factors, including: 1) the
EMC did not resolve the water quality problems raised by state and
federal agencies; 2) the EMC relied upon unfinished studies and
future hypothetical actions; 3) the EIS was inadequate because it did
not fully show and analyze all of the impacts of the dam and lake and
did not address all reasonable alternatives; 4) it was arbitrary and
capricious for the EMC to approve a water supply project that cannot
guarantee that the water it supplies is drinkable and protective of
public health and safety; 5) the EMC erred in approving the Dam
absent sufficient assurances of adequate water quality; 6) the EMC
erred in basing its decision contingent upon unfinished studies; 7)
the EMC erred on relying on an EIS which failed to consider all of the
reasonable alternatives.
In June 1995, DEHNR and the EMC (along with the Piedmont Triad
Water Authority) appealed that decision in the NC Court of Appeals.
The Court of Appeals stated that the plaintiffs (EMC/ DEHNR and
PTRWA) were entitled to a contested case hearing in the office of
Administrative Hearings (OAH) before the case was sent to the
Superior Court. The Superior Court judge denied this OAH hearing.
Thus, the Superior Court was "without jursidiction to conduct a
judicial review, and the order of that court reversing and vacating the
decision of the EMC is vacated". The case was then sent back to the
OAH for a contested case hearing, and then the EMC could then issue a
decision based on the new record. In other words, the case should
not have gone to Superior Court when it did and therefore the case
had to start over at OAH, and the decisions made by the Superior
Court were over-turned.
At this time the Coalition dropped the case (supposedly due to lack of
funds to pay atty. fees). So the project stands as it was after the
EMC's original approval in 1991 - the certificates authorizing the
Randleman Lake project are a done deal and the EIS was finalized and
approved.
WHAT DO WE DO NOW?
I have been asked by the Planning Branch Head (Greg Thorpe) to do
research into the basis for the EMC's decision (including what
additional studies they wanted to be completed as part of that EIS),
what exactly has been approved up to now, and what all the EISs said
about WQ in this area. I will also look into the EIS that is due out this
week from the Corps. I hope I can, in the next few weeks, accumulate
a decent history of all these projects as they have dealt with WQ in
the lake. I will let you know of my results when they are available.
Once that happens, I will sit down and discuss options on how to
proceed on the EA with pertinent DWQ staff.
Please let me know if you think you might want to meet again on this
or have any questions or comments.
If any of the minutes above are incorrect, please let me know and I
will correct.
Thanks!
Michelle L. Suverkrubbe, AICP
Environmental Specialist
Incoming Message High Point Meeting on 7/7 Page 5 of 5
NC Department of Environment Health and Natural Resources
Division of Water Quality, Planning Branch
512 N. Salisbury Street
P.O. Box 29535
Raleigh, NC 27626-0535
[phone] x 567