WQ0000461_Report of Review of Comprehensive Site Assessment (CSA)_20220316

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
S. DANIEL SMITH
Director
NORTH CAROLINA
Environmental Quality
March 16, 2022
Mr. Chad Witherspoon, Plant Environmental Quality Manager
Louisiana-Pacific Corporation
Post Office Box 98
Roaring River, North Carolina 28669
Subject:
Revised Comprehensive Site Assessment and Corrective Action Plan
Louisiana Pacific Corporation, Roaring River, Wilkes County, NC
Permit No. WQ0000461; Groundwater Incident No. 88231
Wilkes County
Dear Mr. Witherspoon:
The Division of Water Resources Winston-Salem Regional Office staff have reviewed the
subject report prepared by TRC Environmental Corporation received on January 28, 2022.
This review concluded that the revised Comprehensive Site Assessment (CSA) requires
additional information. Also, the Corrective Action Plan (CAP) should be prepared and
submitted after the CSA has been completed and approved. This letter will address the
deficiencies found in the revised CSA only.
As stated in our July 28th, 2021 letter, a CSA is required for contamination incidents at
permitted facilities when groundwater contamination occurs at or beyond a compliance
boundary as specified in 15A NCAC 02L .0106 (d) and (e). For this requirement, the CSA
needs to follow the format outlined in 15A NCAC 02L .0106 (g), which states that the CSA
shall include "(1) The source and cause of contamination; (2) Any imminent hazards to
public health and safety, as defined in G.S. 130A-2, and any actions taken to mitigate them
in accordance with Paragraph (f) of this Rule; (3) All receptors and significant exposure
pathways; (4) The horizontal and vertical extent of soil and groundwater contamination and
all significant factors affecting contaminant transport; and (5) Geological and
hydrogeological features influencing the movement, chemical, and physical character of the
contaminants." Our review of the report indicates that some of these components are
missing or insufficient.
Based on 15A NCAC 02L .0106 (g)(1), the CSA must determine the source and cause of
contamination. Therefore, the physical and chemical properties of the residuals, the primary
source of contamination, should be thoroughly discussed in the CSA. Total mass/volume of
contaminant(s) that entered the groundwater should be also evaluated in the CSA. Since no
residuals samples could be collected during this CSA, previous study results may be
referenced. Additionally, the CSA stated that offsite sources may be contributing to the
elevated levels of nitrogen in groundwater at the site. In order to determine whether any of
_1121,..„E\9--
North Carolina Department of Environmental Quality I Division of Water Resources
Winston-Salem Regional Office 1450 West Hanes Mill Road, Suite 3001 Winston-Salem, North Carolina 27105
336.776.9800

these off -site sources contribute to the contamination, additional soil and groundwater
samples should be collected at the boundary of the land application field and/or at adjacent
properties. If run-off from non -LP controlled land is also believed to be contributing to
groundwater contamination, storm water samples should be collected and analyzed to
support these non -LP controlled areas as sources of contamination.
15A NCAC 02L.0160 (g)(4) requires delineation of the horizontal and vertical extent of soil
and groundwater contamination. For groundwater, this requires delineation of contaminants
to the concentrations specified in 15A NCAC 02L .0202 at a minimum. Nitrate was detected
in DSI-MW-7I at a concentration of 9.4 mg/L on December 7, 2021, which is significantly
higher than the historical average of 1.26 ug/L and close to the 2L Standard of 10 mg/L. If
this concentration does not decrease in future sampling events, a deeper or bedrock well at
this location will be needed to evaluate whether the bedrock flow zone is impacted or to
further delineate the vertical extent of groundwater contamination.
Contaminated soil can be a secondary source for groundwater contamination. Based on
Guidelines for the Investigation and Remediation of Soil and Groundwater Contamination,
DEQ Division of Water Resources, 2017 (attached) delineation of soil contaminants should
use the Preliminary Soil Remediation Goals (PSRG) and the Transport Model for the
Protection of Groundwater. The PSRG document is listed among the Screening documents
in the Risk Evaluation Resources website (deq.nc.gov/permits-rules/risk-based-
remediation/risk-evaluation-resources). Please ensure that the current version is used since
the PSRG is updated periodically.
The CSA should further evaluate geological and hydrogeological features in accordance
with 15A NCAC 02L.0106 (g)(5) which requires identifying and understanding the geologic
and hydrogeologic factors that affect contaminant fate and transport which is a critical
component of any CSA and CAP. In addition to chemical properties of the contaminants,
subsurface contaminant movement depends on the physical, chemical, and biological
characteristics of the site. Understanding fate and transport is particularly important since
it may significantly affect the outcome of groundwater monitoring, groundwater and
contaminant transport modeling, human and environmental risk assessment, and corrective
action planning The factors that affect contaminant fate and transport involve physical and
(or) chemical processes and generally fall into one of three categories:
• Factors that affect whether the contaminant will be soluble/mobile or
insoluble/immobile,
• Factors that affect the rate and direction of groundwater flow, and
• Factors that affect the migration of contaminant mass as it moves through the
groundwater flow system.
Each factor affecting contaminant fate and transport is dependent upon local conditions. A
thorough evaluation of each of these factors should be included as part of the CSA.
In addition, the following areas must be addressed:
Page 2of3

1. Figure 4, Former Land Application Field Surface Water Runoff Flow Direction,
should be revised since there is an unnamed creek between field #LP-25 and the
adjacent property west of the site. Surface water near the creek runs off from the
fields into the creek and then flows into the Yadkin River, not from west to east as
illustrated on the CSA map. Both creeks should be identified on this map and other
relevant figures.
2. All existing monitoring wells should be sampled. Generally, concentrations of
metals in groundwater may be affected by the land application of residuals. If you
do not intend to sample groundwater for metals, please explain why. The CSA is not
a permit compliance monitoring process but a 2L compliance assessment.
3. Dissolved oxygen (DO) should be measured in the field during each sampling event
for each monitoring well. DO is an important constituent affecting denitrification
which can affect nitrate concentrations significantly.
4. The Yadkin River should be resampled for the same parameters as sampled for
groundwater. The two unnamed creeks bordering field LP-25 at the eastern and
western sides should also be sampled for these parameters.
By April 18, 2022, please submit a brief workplan to this office outlining how the issues
mentioned above will be addressed and provide a timeframe for submitting a complete CSA.
If you have any general questions regarding how this CSA should be conducted and how
the report should be compiled, please refer to the attached Guidelines for the Investigation
and Remediation of Soil and Groundwater Contamination, DEQ Division of Water
Resources, 2017. For site specific questions or if you have any problems meeting the
deadline, please do not hesitate to contact Jim Gonsiewski, or Shuying Wang at (336) 776-
9800 or via email ([e-mail] or [e-mail]). Thank you
for your cooperation.
Sincerely,
,----DocuSigned by:
L-Oh. 1 . JM hr
‘*--145B49E225C94EA...
Lon T. Snider
Regional Supervisor
Water Quality Regional Operations Section
Division of Water Resources, NCDEQ — WSRO
enc: GUIDELINES FOR THE INVESTIGATION AND REMEDIATION OF SOIL
AND GROUNDWATER CONTAMINATION, NCDEQ Division of Water
Resources, 2017
cc: Michelle Hays, P.G., TRC Environmental Corporation (Electronic Copy)
WSRO Electronic Files
Laserfiche Files
Page 3 of 3