MO-3079_6722_G_NORR_20230714_Additional Risk Assessment

July 14, 2023

Michael Peebles
1355 Oakridge Farm Highway
Mooresville, NC 28115

Re:Notice of Regulatory Requirements
15A NCAC 2L .0407(d) [Intermediate Risk]
Risk-based Assessment and Corrective Action
For Petroleum Underground Storage Tanks

Former Mooresville Amoco
151 South Broad Street
Iredell County
Incident Number: 6722
Risk Classification: Intermediate
Ranking: I-115-D

Dear Mr. Peebles:

The Limited Site Assessment Report received on March 4, 2010 has been reviewed by the UST
Section, Division of Waste Management, Mooresville Regional Office. The review indicates soil
contamination exceeds the lower of the residential or soil-to-groundwater MSCCs referenced in Title 15A
NCAC 2L .0411, and groundwater contamination exceeds the groundwater quality standards established in
Title 15A NCAC 2L .0202 The risk posed by the discharge or release at the subject site is classified by the
Department of Environmental Quality as intermediate, as stipulated under Title 15A NCAC 2L .0406. The
land use at the site is classified as industrial/commercial. Please note that Title 15A NCAC 2L .0407(a)
requires you to notify the Department of any changes that might affect the risk or land use classifications
that have been assigned.
Title 15A NCAC 2L .0407(d) [Intermediate Risk] requires you to comply with the assessment and
cleanup requirements of Title 15A NCAC 2N .0706 and Title15A NCAC 2L .0106(c) and 2L .0106(g).
Failure to comply in the manner and time specified may result in the assessment of civil penalties and/or the use of other enforcement mechanisms.
Typically, a Comprehensive Site Assessment (CSA) Report prepared in accordance with these
requirements and the most recent version of the Guidelines for Assessment and Corrective Action for UST
Releases submitted to this office within 90 days of the date of this notice would satisfy this requirement.
Alternatively, an extension to this deadline may be obtained through the completion and submittal of a
Risk Assessment Report within 90 days of this notice. This report supplements the LSA through the
assessment of groundwater characteristics and the risk to nearby receptors. Specifically, the Risk
Assessment Report should include, at a minimum:

North Carolina Department of Environmental Quality | Division of Waste Management
Mooresville Regional Office | 610 East Center Avenue | Suite 301 | Mooresville, NC 28115 | [phone]

• The installation of three horizontal extent monitoring wells and one vertical extent monitoring well.
One monitoring well shall be installed upgradient of the source of contamination and two
monitoring wells shall be installed downgradient of the source of contamination, as best as can be
determined, and located such that groundwater flow direction and hydraulic gradient may
accurately be determined. The vertical extent monitoring well shall be installed immediately
downgradient of the source area of contamination, as best as can be determined, with any drilling
greater than a depth of 75 feet requiring authorization from the regional office incident manager.
Note, the vertical extent monitoring well must not connect aquifers.
• The analysis of representative soil samples collected during the construction of the monitoring
wells. One soil sample must be collected in the unsaturated zone and one in the smear/saturated
zone from suspected worst-case locations exhibiting visible contamination or elevated levels of
volatile organic compounds based on field screening techniques. Only the suspected most
contaminated soil sample in each zone from each boring should be submitted for laboratory analysis
using the EPA 8015B TPH (or equivalent) appropriate for the fuel types suspected in the release.
• The collection of groundwater samples from the new monitoring wells, analyzed by the appropriate
method(s) for the constituents relevant to the release.
• The collection of groundwater samples from any onsite water supply wells and any water supply
wells located adjacent to the site less than 250 feet from the source area of the release, analyzed by
the appropriate method(s) for the constituents relevant to the release. Sampling of more than 5
water supply wells will require approval of the regional office incident manager.
• The survey of all monitoring wells and collection of potentiometric data for the completion of a
potentiometric surface / groundwater elevation and flow map.
• The completion of one aquifer slug test in a representative well to provide a calculation of hydraulic
conductivity, transmissivity, and linear groundwater velocity.
Because a release or discharge has been confirmed, a Licensed Geologist or a Professional
Engineer, certified by the State of North Carolina, is required to prepare and certify all reports submitted to
the Department in accordance with 15A NCAC 2L .0103(e) and 2L .0111(b).
Effective October 1, 2004, the Department of Environmental Quality requires that all work not
determined to be an emergency response or associated with risk assessment (i.e., the Limited Site
Assessment Report, per Title 15A NCAC 2L .0405) must be preapproved if State Trust Fund reimbursement
is anticipated. To comply with this requirement for a CSA, a completed Preapproval/Claim Authorization
Form, encompassing the required comprehensive assessment activities must be received in this office
within 14 days of the date of this letter.
However, as the Risk Assessment Report qualifies as an exempted scope of work, written
preapproval is not required to complete the activities described above, as documented under Task 2.610 in
the 2022 Reasonable Rate Document, Version 4/1/2022. Upon completion of any eligible activities, you
should submit your claim promptly. Reimbursement funds are budgeted based on completed preapprovals,
but delays in reimbursement or even denial due to exceeding the statute of limitations on claiming eligible
costs can result where claims are not submitted immediately following work completion.
Please note that before you sell, transfer, or request a “No Further Action” determination for a
property that has not been remediated to below “unrestricted use” standards, you must file a Notice of
Residual Petroleum ("Notice") with the Register of Deeds in the county where the property is located
(NCGS 143B-279.9 and 143B-279.11).

North Carolina Department of Environmental Quality | Division of Waste Management
Mooresville Regional Office | 610 East Center Avenue | Suite 301 | Mooresville, NC 28115 | [phone]

If you have any questions regarding trust fund eligibility or reimbursement from the Commercial
Leaking Petroleum Underground Storage Tank Cleanup Fund, please contact the UST Section Trust Fund
Branch at [phone]. If you have any questions regarding the actions that must be taken or the rules
mentioned in this letter, please contact me at [e-mail] or at 04-235-2175.

Sincerely,

Ryan C Mills
Environmental Program Consultant
Mooresville Regional Office
UST Section, Division of Waste Management, NCDEQ

cc: Brady Freeman, Iredell County Health Department (Via Email)
Ryan R Osborne, P.E., INENCO (Via Email)