NCG020273_Final COC with Special Renewal Letter_20151119

North Carolina Department of Environmental Quality
Pat McCrory
Governor
Rick Solazzo
Senior V.P., Environmental Affairs
Unimin Corporation
258 Elm Street
New Canaan, CT 06840
Dear Mr. Solazzo:
Donald R. van der Vaart
Secretary
November 19, 2015
Subject: General Permit No. NCG020000
Unimin Corporation —
Buna Mine
COC NCG020273
Mitchell County
In accordance with your request for renewal of a discharge permit received on May 30, 2014, we are
forwarding herewith the subject certificate of coverage to discharge under the subject state — NPDES general
permit. This permit is issued pursuant to the requirements of North Carolina General Statute 143-215.1 and
the Memorandum of Agreement between North Carolina and the US Environmental Protection Agency
dated October 15, 2007 (or as subsequently amended).
Please take notice that this certificate of coverage is not transferable except after notice to the
Division of Energy, Mineral, and Land Resources. The Division may require modification or revocation and
reissuance of the certificate of coverage (COC).
Please be advised that EPA Region 4 staff who performed a Compliance Sampling Inspection (CSI) at
the end of March 2015 and follow-up sampling in June 2015 at other industrial mineral mines in North
Carolina raised concerns about metals levels in the discharges. The Stormwater Permitting Program
identified mines like this one that have similar activities. During the term of this General Permit, this site may
be evaluated further for an alternative permitting action, such as applying to the Division of Water Resources
(DWR) for an individual NPDES discharge permit (or modification of its existing wastewater individual permit)
prior to the expiration of this General Permit in 2020.
This permit does not affect the legal requirements to obtain other permits which may be required by the
Division of Energy, Mineral, and Land Resources, or permits required by the Division of Water Resources
(DWR), Coastal Area Management Act, or any other federal or local governmental permit that may be
required. If the conditions as stipulated in the COC are unacceptable to you, you may apply sooner for an
individual NPDES discharge permit.
Division of Energy, Mineral, and Land Resources
Energy Section • Geological Survey Section • Land Quality Section
512 North Salisbury Street, Raleigh, North Carolina 27604 • Internet: http://portal.ncdenr.org/web/Ir/
eb/Ir/
Mailing Address: 1612 Mail Service Center, Raleigh, North Carolina 27699-1612.919-707-9200 / FAX: [phone]
An Equal Opportunity 1 Affirmative Action Employer— 50% Recycled 110% Post Consumer Paper

NCG020273 Renewal COC
November 19, 2015
Page 2
If you have any questions concerning this permit, please contact Bradley Bennett at telephone number
[phone], or Bethany Georgoulias at telephone number [phone].
Sincerely,
Original signed by Bradley Bennett
for Tracy E. Davis, P.E., CPM
cc: Toby Vinson, DEMLR Land Quality Section
Tom Belnick, DWR Water Quality Permitting Section
Stan Aiken, DEMLR Asheville Regional Office RE
Linda Wiggs, DWR Asheville Regional Office
Kip Tyler, EPA Region IV NPDES Permitting and Enforcement Branch
Stormwater Permitting Program Files
DWR Central Files

Certificate of Coverage
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF ENERGY, MINERAL AND LAND RESOURCES
GENERAL PERMIT NO. NCG020000
CERTIFICATE OF COVERAGE No. NCG020273
STORMWATER AND WASTEWATER DISCHARGES
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
Page 1 of 1
In compliance with the provision of North Carolina General Statute 143-215.1, other lawful standards and
regulations promulgated and adopted by the North Carolina Environmental Management Commission, and the
Federal Water Pollution Control Act, as amended,
Unimin Corporation
is hereby authorized to discharge stormwater and/or wastewater, as provided in the original Certificate of
Coverage (COC), or subsequent COC modification, from a facility located at:
Buna Mine
Hwy 226 N
Spruce Pine
Mitchell County
to receiving waters designated as North Toe River, class C;Tr water(s) in the French Broad River Basin
(s) in accordance with the stormwater pollution management requirements, monitoring and reporting
requirements, and other conditions set forth in Parts I, II, III, IV, V, and VI of General Permit No.
NCG020000 as attached.
This Certificate of Coverage shall become effective October 1, 2015.
This Certificate of Coverage shall remain effective for the duration of the General Permit.
Signed this day October 1, 2015.
for Tracy E. Davis, P.E., CPM
Director, Division of Energy, Mineral and Land Resources
By the Authority of the Environmental Management Commission
http://portal.ncdenr.org/web/lr/2015-erenewal 11/19/2015