NCG020089 H1 West Exceedance Letter 20240318

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VIRONMENTAL
March 18, 2024
N.C. Department of Environmental Quality
Division of Water Resources
Attn: NC DEQ Mooresville Regional Office
610 East Center Avenue, Suite 301
Mooresville, NC 28115
Re: Imerys Mica Kings Mountain
NCG 020089
H1 West Tier 1 Response
To Whom It May Concern:
Analytical sample results for the first sampling period of 2024 at the H1 West stormwater outfall
potentially exceeded a benchmark value for turbidity. The laboratory result for turbidity was 55
NTU and the permit references a stream and surface water turbidity benchmark of 50 NTU in
section H-5. The outfall is located near the Western boundary of the mine and the sample is
collected directly from the culvert of the stormwater control measure. The flow path from the
outfall to the nearest receiving water includes approximately 110 linear feet of rip-rap before
reaching a stream near the boundary of the H1 mine. Since the outfall discharges into the
upper limit of the receiving water it is not possible to collect a sample upstream of the outfall.
Additionally, the receiving water is an intermittent tributary which only contains flow for a portion
of the year.
Details:
Mine: Moss
Site: H1
Outfall: H1 West
Sample Type: Wastewater
Sample Date: March 06, 2024
Lab Results Date: March 08, 2024
General Timeline:
Continuously: Exceedance has been documented in SWPPP.
Within 2 Weeks: Notify NC DEQ Regional Office in writing (This letter: March 18, 2024).
Conduct inspection (By March 22, 2024)
Within 1 Month: Select course of action by April 08, 2024.
Within 2 Months: Implement selected feasible action by May 08, 2024.
Cause of Exceedance:
At the time of this notification the cause of the exceedance is unknown. The inspection will be
completed by March 22, 2024.
Remedial Action Plan:
An action plan will be developed and implemented according to the above timeline once the
inspection is completed, and a feasible course of action is selected.
ATLAS Environmental, Inc.
338 S.Sharon Amity Road #411 Charlotte, North Carolina 28211
704-512-1206(o)/828-712-9205(m)
www.atlasenvi.com/Offices in Asheville and Charlotte

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Please let me know if you have any questions.
Best regards,
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Jennifer L Robertson, President
ATLAS Environmental, Inc.
338 S.Sharon Amity Road #411 Charlotte, North Carolina 28211
704-512-1206(o)/828-712-9205(m)
www.atlasenvi.com/Offices in Asheville and Charlotte