NC0090000_Report_20231102

CDColonial Pipeline Company
Jeff Morrison
Environmental Program Manager, Remediation NOV 0 2 2023
October 31. 2023 NCDEQ/DWR/NPDES
North Carolina Department of Environmental Quality
Division of Water Resources — Water Quality Permitting Section NPDES
1617 Mail Center Service Center
Raleigh. NC 27699-1617
Re: 2023 NPDES Biological Integrity Study Plan
Colonial Pipeline Company — 2020-L1-SR2448 / Pipeline ROW Release
NPDES Permit No. NC0090000
Huntersville. Mecklenburg County, North Carolina 28078
To Whom it May Concern
Please find attached a Study Plan for the proposed scope of work for the macroinvertebrate
community assessment at the Colonial Pipeline Company (CPC) property, near Huntersville.
Mecklenburg County. North Carolina (the Site). The Study Plan and annual survey are required
for compliance with the terms of CPC's NPDES Permit NC0090000 Section A. (5.) Instream
Assessment of Biological Integrity (Annual). This NPDES Permit is associated with a proposed
discharge (Outfall 001) into the North Prong of Clark Creek where the creek crosses under
Huntersville — Concord Rd. at approximately 35.420216, -80.797979. The Study Plan has been
prepared consistent with the requirements outlined in the 2016 North Carolina Department of
Environmental Quality (NCDEQ) Standard Operation Procedures (SOP) for the Collection and
Analysis of Benthic Macroinvertebrates.
If you have any questions or concerns regarding the work plan, please do not hesitate to contact
me at [phone].
Respectfully.
Jeff D. Morrison
3925 Anderson Farm Road,Austell,Georgia 30106
colpipe.com I Follow us: 000Q

RECEIVED
III
_ NOV 0 2 2023
F
NCDEQ/DWR/NPDES
NPDES Biological Integrity Study Plan
Colonial Pipeline Company (CPC)
NPDES Permit NC0090000
Huntersville, Mecklenburg County, North Carolina
Prepared by:
TRC Environmental Corporation
50 International Drive, Suite 150
Greenville, SC 29615
October 2023
/40-llth -d. AALL /,
ejaci-Cz-cA_
Heather Smith Kari C. Saucier, Ph.D.
Senior Biological Scientist Vic -President, Senior Consultant
TRC Environmental Corporation I Colonial Pipeline Company
NPDES Biological Integrity Study Plan
I IEMPLOYEES.ROOT.LOCAL I ENVI ECCI GREENVILLEI WPGVLI PIT21568543100001 R5685430000-001 NPDES BIOLOGICAL INTEGRITY STUDY PLAN.DOCX
50 INTERNATIONAL DRIVE,SUITE 150,GREENVILLE,SC 29615,•864.281.0030 PHONE•864.281.0288 FAX•WWW.TR000MPANIES.COM

Table of Contents
1. Introduction 1
2. In-Stream Assessment of Biological Integrity 3
2.1 Sampling Approach and Locations 3
2.2 Sampling Methods 4
2.3 Laboratory Methods S
3. Reporting 7
4. Schedule 8
5. References 9
List of Figures
Figure 1 Site Location Map 2
Figure 2 Sample Location Map 6
List of Appendices
Appendix A Sampling Location Photo Log
TRC Environmental Corporation / Colonial Pipeline Company 1
NPDES Biological Integrity Study Plan October 2023
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Section 1
Introduction
The Colonial Pipeline Company(CPC)was issued National Pollutant Discharge System (NPDES) Permit
NC0090000 associated with the 2020-L1-SR2448 Release Site located near Huntersville, Mecklenburg
County, North Carolina (the Site). NPDES Permit NC0090000 addresses a planned discharge from a
water treatment facility to be installed at the Site. CPC is required to perform in-stream biological
integrity assessments consistent with Permit Condition A. (5.)of the NPDES Permit. The Site is situated
on both sides Huntersville-Concord Road (State Road 2448 [SR 2448])as shown in Figure 1. CPC
contracted TRC Environmental Corporation (TRC)to develop the Biological Integrity Study Plan in
support of Permit Condition A. (5.)of NPDES Permit NC0090000.
The area within a 1,500-foot radius of the Site is a mixture of low-density residential properties,
agricultural properties, and wooded land. The Site is located within the Yadkin Pee-Dee River Basin.
North Prong Clarke Creek is located approximately 1,800 feet north of the Site and South Prong Clarke
Creek is located approximately 2,700 feet south of the Site, both of which are characterized by the
North Carolina Department of Environmental Quality(NCDEQ) Division of Water Quality as Class C water
bodies, meaning that they are protected for non-drinking water purposes such as biological integrity,
fishing, and infrequent secondary recreational purposes (i.e.,wading).
Mecklenburg County is located within the Piedmont physiographic province, characterized by rolling
hills and moderately steep valleys formed by stream erosion of upland areas. Elevations at the Site
range from approximately 650 to 750 feet above mean sea level. The surficial soils at the Site consist
almost entirely of fine-grained clayey to silty saprolite developed from the weathering of the underlying
bedrock.The soil thickness ranges from a few feet to greater than 100 feet. Data obtained from
completed borings indicate the Site is underlain by quartz diorite.
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NPDES Biological Integrity Study Plan October 2023
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IDLE
SITE LOCATION MAP
DRAWN BY M.BILLINGS PROD.NO. 588543
CHECKED BY R.SPRING
APPROVED BY B.FEUERSTEIN FIGURE
DATE OCTOBER 2023
DATABASE MAP OURCUESSTRC,ESRI TOPOGRAPHICONUNE SERVICE 0 4v FEET 1419 ROCK QUARRYD
SUITE 1A16
T�C RALEIGH,NC 27610
19,600 1-=800' PHONE [phone]
FILE HUNTERSVILLE NC

Section 2
In-Stream Assessment of Biological Integrity
Permit Condition A. (5.)to the NPDES Permit NC0090000 requires an annual instream assessment of
biological integrity. The NCDEQ Full Scale method will be used to determine bioclassifications and water
quality ratings. This method is typically used for most between-site and/or between-date comparisons
(NCDEQ 2016).
2.1 Sampling Approach and Locations
To satisfy this condition,TRC and their North Carolina certified biologist propose two Full-Scale benthic
macroinvertebrate surveys at two sampling locations. The proposed macroinvertebrate sampling
locations share similar riparian and geomorphological characteristics,such as substrate composition and
incised stream channel. The proposed upstream reference site is located in a forested area formerly
part of the Oehler Nature Preserve and is located approximately 2,400 feet upstream of Outfall 001 at
Huntersville-Concord Rd. The proposed downstream experimental site is located approximately
1,500 feet downstream of Outfall 001 in between forested private property. The watersheds for the
upstream reference site and the downstream experimental site are comparable in that both watersheds
are approximately 3 square miles in area and composed of forested lands, developed lands, agricultural
lands, and impervious surfaces(USGS StreamStatsl . The proposed macroinvertebrate sampling
p ) p P p g
locations are shown on Figure 2 and Appendix A contains a photo log showing upstream and
downstream vantage points within the proposed sampling reaches.
NCDEQ requires that North Carolina certified biologists implement the biological integrity assessment
program. TRC subcontracted a North Carolina certified biologist from Michael Baker International (MBI)
in Asheville, North Carolina to support preparation and implementation of the biological integrity
assessment program. TRC proposes to conduct Full Scale benthic macroinvertebrate surveys on the
following schedule:
■ a baseline event before discharge commences in Spring 2024(before June 1, 2024),to establish
baseline biological conditions, and
• subsequent annual surveys,following commencement of discharge, conducted in Spring 2025
(prior to June 15`) and each year after until permit condition modification or permit expiration.
With each planned field event,CPC shall provide the supervisor for the Biological Assessment Branch,
Water Sciences Section 30-days' notice of sampling so that Division personnel may attend, and share
samples collected, if desired.
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NPDES Biological Integrity Study Plan October 2023
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2.2 Sampling Methods
To monitor physical habitat conditions at the site,TRC and their North Carolina certified biologist
subcontractor will assess in-stream and riparian habitat conditions at each of the sampling locations using
NC Habitat Assessment sheets. Metrics from the assessment sheets will be used to generate a habitat
score for each sampling location. Metrics will include instream habitat, substrate composition, pool
variety, riffle habitat, bank stability and vegetation, light penetration, and riparian vegetation zone width.
Water quality parameters will also be collected at each sampling location with a calibrated YSI style
meter. Water quality parameters include temperature,dissolved oxygen, specific conductivity, and pH.
The macroinvertebrate samples will be collected according to the specifications outlined in the 2016
NCDEQ Standard Operating Procedures for the Collection and Analysis of Benthic Macroinvertebrates,
which provides detailed standard operating procedures for the collection and analysis of freshwater
benthic macroinvertebrate data that can help determine bioclassification ratings (NCDEQ 2016).
TRC and their North Carolina certified biologist subcontractor will use the following techniques
associated with the full-scale method to assess the macroinvertebrate community at the sampling
locations;two riffle kicks,three sweeps, one leaf-pack,two rock-and log-washes, one sand grab, and
visual observations. Sampling will begin at the most downstream point of each reach with scientists
traveling upstream to new macroinvertebrate sampling locations. This approach reduces the amount of
stirred-up sediment washing downstream and potential disturbance to macroinvertebrates.
The riffle-kick method uses kicknets or D-frame nets, and substrate is surveyed for approximately two
meters. The kick-nets are placed perpendicular to the streambed and sediment will be disturbed on the
upstream side of the net so the disturbed contents wash into the net. The sweep collection method
requires a sweep net to be used to sample locations such as undercut banks, root mats and aquatic
vegetation. The leaf-pack collection method requires the collection of a leaf-pack,which should target
deciduous material when possible. The leaf-pack is collected and then the collected material is washed
and ultimately poured over a sieve bucket.The rock-and log-wash collection method requires larger
substrate material to be collected and then washed into a plastic container where the remaining
g
material is then poured through a fine-mesh sampler. The sand collection method specifically targets
macroinvertebrates that live in the sand. For the sand collection method, a kicknet will be placed
downstream of the sand substrate to be sampled and sediment will be disturbed, and the disturbed
material will be collected in the kicknet. The visual method requires the sampling team make visual
inspections of the sampling locations mainly targeting larger macroinvertebrates (NCDEQ 2016).Any
larger macroinvertebrates will be placed into a vial containing 70%ethanol. The remaining contents
from each Full-Scale sampling method will be placed into a labeled container and preserved in 70%
ethanol. The preserved samples will be transferred to MBI's Asheville, NC based lab for processing.
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NPDES Biological Integrity Study Plan October 2023
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2.3 Laboratory Methods
After arrival at the lab,the contents of each sample will be sorted to separate macroinvertebrates from
the organic material. Sorting will be conducted under a dissecting microscope. Sorted
macroinvertebrates will be preserved in 70%ethanol and identified to the lowest practical taxonomic
level, using a high power(40X)dissecting microscope. However, selected chironomid (non-biting midge)
larvae and oligochaetes (aquatic earthworms) may be slide-mounted and examined under a compound
microscope with up to 1600X magnification to allow greater taxonomic resolution. Taxonomic
identification will undergo Quality Assurance/Quality Control by TRC Scientist James Treacy, a Society
for Freshwater Scientist certified taxonomist.
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NORTH o'
AROLINA
Proposed
Outfall 001
Proposed Upstream
Reference Sample
Proposed Downstream
Sample
SITE LOCATION
•
7.1
77.
•
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PR01ECT COLONIAL PIPELINE COMPANY
Release>de 2020-L1-SR2448 RELEASE
HUNTERSVILLE,NC
TITLE
SAMPLE LOCATION MAP
DRAWN BY. M.BILLINGS PROD NG 588543
CHECKED BY R.SPRING
AM:ROVED BY B.FEUERSTEIN FIGURE 2
DATE. OCTOBER 2023
BASE MAP USGS TOPOGRAPHIC ONLINE SERVICE. 0 400 800 1429 ROCK QUARRY ROAD
DATA SOURCES:MC,ESRI.USGS
0 FEET SUITE 118
TR C EIGH,NC 2T610
13.600 1'=600' PHONE [phone]
FILE HUNIRISVLLE NC

Section 3
Reporting
The macroinvertebrate data collected during the study plan implementation will be used to calculate
tolerance values and will be compared with the North Carolina biotic index. Tolerance values are a
macroinvertebrate index that refers to the pollution tolerance levels of each macroinvertebrate taxon.
The North Carolina biotic index is modeled after the Hilsenhoff Biotic Index(Hilsenhoff 1987) and is a
given sample's weighted average of tolerance values for the macroinvertebrate species identified with
respect to their abundance(NCDEQ 2016).
TRC will prepare an annual report summarizing the methods, results, and important findings. The report
will include tables and figures related to macroinvertebrate identification and will be submitted in
electronic format to NCDEQ/Division of Water Resources within 60 days of completion of the
taxonomic analysis of samples.
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Section 4
Schedule
The proposed biological integrity schedule is as follows and is based upon the NC Certified Biologist
subcontractor availability and an assumption on the timeframe for obtaining Biological Integrity Study
Plan approval:
Proposed Activities Proposed Dates
Study Plan Submission November 1, 2023
Anticipated Study Plan Approval On or before January 31, 2024
lnstream Macroinvertebrate Community April/May 2024*
Assessment
Reporting July 2024'
* Dependent upon schedule and access—specific dates will be conveyed to the Division prior to initiating field
work.
" This date is approximate depending on completion of taxonomic analyses.
Schedule for in-stream activities will be dependent upon appropriate site and weather conditions.
Sampling during a period of no, low or moderate flow is acceptable; however, sampling during a rising
hydrograph or extremely high flows would not allow for representative data to be obtained.
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Section 5
References
Barbour, M.T.,J. Gerritsen, B.D. Snyder, and J.B. Stribling. 1999. Rapid Bioassessment Protocols for
Use in Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates and Fish,
Second Edition. EPA 841-B-99-002. U.S. Environmental Protection Agency; Office of Water;
Washington, D.C.
Hill, B.H., R.J. Stevenson,Y. Pan,A.T. Herlihy, P.R. Kaufmann, and C.B.Johnson. 2001. Comparison
of correlations between environmental characteristics and stream diatom assemblages
characterized at genus and species levels.Journal of the North American Benthological Society,
20(2):299-310.
Hilsenhoff,W. L. 1988. Rapid field assessment of organic pollution with a family-level biotic index.
Journal of the North American Benthological Society, 7(1), 65-68.
Hilsenhoff,W. L. 1998.A modification of the biotic index of organic stream pollution to remedy
problems and permit its use throughout the year.The Great Lakes Entomologist, 31(1), 1.
Lillie, Richard A. Szczytko,Stanley W., Miller, Michael A. 2003. Macroinvertebrate data
interpretation guide. (pp. 30-32). Wisconsin Department of Natural Resources.
Mandaville, S. M. 2002. Benthic macroinvertebrates in freshwaters:Taxa tolerance values, metrics,
and protocols(pp. 21-38). Nova Scotia: Soil &Water Conservation Society of Metro Halifax.
North Carolina Department of Environmental Quality, Division of Water Resources,Water Sciences
Section, Biological Assessment Branch, 2016. Standard Operating Procedures for the Collection
and Analysis of Benthic Macroinvertebrates (Version 5).
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Appendix A
Sampling Location Photo Log
TRC Environmental Corporation I Colonial Pipeline Company
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Proposed Sample Site Photo Log
7611
17
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Facing upstream on the proposed reference reach Facing downstream on the proposed reference
� of the North Prong nfClarke Creek. reach of the North Prong of Clarke[reek.
AL
Facing upstream on the proposed experimental Facing downstream on the proposed experimental
� reach of the North Prong of Clarke Creek. Proposed reach of the North Prong of Clarke Creek.
� location of0utfaU 001 in view(culvert).
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