20120632 Ver 1_More Info Received_20120928

C1earWater Environmental Consultants, Inc.
September 27, 2012 www.cwenv.com
Ms. Linda Wiggs
NC Division of Water Quality
Surface Water Protection Section
2090 US Highway 70
Swannanoa, North Carolina 28778
RE: Response to DWQ Request for More Information
West School House Mine Expansion
Avery County, North Carolina
Action ID SAW- 2011 - 01762; DWQ Project # 2012 -0632
Ms. Wiggs,
Please reference the letter dated August 9, 2012 (Attachment A) sent by the NC Division
of Water Quality (DWQ) in response to the permit application submitted by ClearWater
Environmental Consultants, Inc. (CEC), on behalf of the Unimin Corporation represented
by Mr. Rolf Pippert. The permit application requested written authorization for the
impacts associated with the expansion of the mining pit located at the Unimin
Corporation's West School House mine. The comments provided by the DWQ are
summarized and discussed below.
DWQ Comment la: "How will downstream flows and temperature be monitored to
maintain compliance with water quality standards 15A NCAC 02B.211 (1) and (3)6)."
The Unimin Corporation proposes to monitor temperature and flow in the stream
channel below the proposed pit expansion. At least two monitoring stations will
be established below the proposed pit expansion. Each station will be monitored
quarterly for 3 years. Upstream and downstream photographs to document flow,
along with a temperature measurement, will be taken at each station and the data
will be sent to the DWQ quarterly for review.
DWQ Comment 1 b: "How will water quality standards 15A NCAC 02B.211 (3)(k) in the
receiving stream be achieved."
The Unimin Corporation has obtained the appropriate Division of Land Quality
(DLR) sediment and erosion control permits for development at the site.
Treatment and dewatering ponds are existing at the site and will continue to be
used during expansion of the pit (Figure 1). Sediment and erosion control
measures at the site are in compliance with DLR standards and revent sediment
loss at the site and significant increases in turbidity. p 1 k
L�
224 South Grove Street, Suite F
Hendersonville, NC 28792
828 - 698 -9800 Tel SEP 2 $ 2012
828 - 698 -9003 Fax DENR .
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Ms Linda Wiggs
09.27.12
Page 2 of 3
DWQ Comment 2a: "Section 8.2.2 states that during construction the suspended
solids /turbidity may be increased but only minimally and temporarily. How much and for
how long do you expect an increase? What is the expected life of the mine ?"
Minor increases in turbidity are expected during land clearing activities at the site.
After trees and topsoil are removed from the site, the area will be stabilized. Land
clearing and stabilization is expected to take 2 -3 months. During this time, BMPs
such as, silt fencing, berms, swales, sediment basins, etc., will be utilized to
contain sediment at the site.
The proposed pit expansion would add approximately 15 years of production to
the existing pit design, bringing the total "expected life" of the mine to
approximately 25 years.
DWQ Comment 2b: "Section 8.2.3 and 9.15 states accumulated water in the mining pit
will be treated by existing stormwater facilities at the site. This project will increase
flows to these stormwater facilities; there will be the natural stream flows and
stormwater runoffflows that have to be managed. Please explain how these flows will be
diverted to the existing stormwater facilities? Please explain how the existing
stormwater facilities are of sufficient size to handle these added flows while maintaining
compliance with Stormwater Permit NCG020795 benchmarks and avoiding water quality
standard violations? "
The proposed pit expansion encompasses the headwaters of the stream proposed
for impact. Natural stream flows within the expansion will be altered and
groundwater intercepted during the pit expansion will accumulate in the bottom of
the pit. A water collection basin will be constructed in the bottom of the pit. This
basin will be fitted with a pump and collected water will be pumped to the
existing dewatering basin at the site (Figure 1). The dewatering pond is regulated
by a NPDES General Stormwater permit issued by the NC Division of Water
Quality (DWQ). This permit includes quarterly monitoring of the dewatering
pond discharge. Unimin has remained in compliance with standards set forth in
the NPDES permit and will continue to monitor discharge from the dewatering
pond throughout the construction of the expansion. Stormwater at the site will
continue to be treated by the existing stormwater basin located south of the
proposed pit expansion (Figure 1).

Ms Linda Wiggs
09 27.12
Page 3 of 3
The applicant believes the information submitted in this package addresses all issues set
forth by the DWQ in the letter dated August 9, 2012. Should you have any questions or
comments concerning this project please do not hesitate to contact me at 828 - 698 -9800.
Sincerely,
Rebekah L. Newton
Project Biologist
Cc: Corps — Tasha McCormick
DWQ�Raleigh
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R. Clement id APW.S. ,
Principal

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Attachment A
DWQ Request for Additional Info
(dated August 9, 2012)

AN -
in
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Charles Wakdd, P E
Governor Director
August 9, 2012
Unimin Corporation -Rolf Pippert
PO Box 588
7638 HWY 226 South
Spruce Pine, NC 28777
Subject: Request for More Information
401 Water Quality Certification
West Schoolhouse Mine Expansion
DWQ Project # 12 -0632
Avery County
Response deadline: September 28, 2012
Dear Mr. Pippert:
Dee Freeman
Secretary
The Division of Water Quality (DWQ) has performed a preliminary review of a 401 Water Quality Certification
application submitted for the above referenced property. Additional information will be required in order to
complete the review process.
Please provide the following information so that we may continue to review your project.
Additional Information Requested:
1. Water Quality Standard Impacts: Mining operations expose large areas of land and alter
topography. Please explain how water quality standards will not be violated downstream,
specifically:
a. Flow and Temperature: How will downstream flows and temperature be monitored to
maintain compliance with water quality standards 15A NCAC 02B.0211 (1) and (3) 6).
b. Turbidity: How will water quality standards 15A NCAC 02B.0211 (3) (k) in the receiving
stream will be achieved.
2. Avoid and Minimize: Stringent Best Management Practices (BMPs) will be needed to avoid
and minimize impacts to the receiving stream. Please describe what BMPs will be used to
protect water quality.
Location 2090 U S Highway 70, Swannanoa, North Carolina 28778
Phone 828 - 29645001 FAX 828 - 299 -7043
Internet www ncwaterqualtty org
An Equal Opportunity 1 Affirmative Action Employer
NorthCarolina
Naturally

Rolf Pippert-Unmmn
August 9, 2012
Page 2 of 2
a. Section 8.2.2 states that during construction the suspended solids /turbidity may be increase
but only minimally and temporarily. How much and for how long do you expect an
increase? What is the expected life of this mine?
b. Section 8.2.3 and 9.15 states accumulated water in mining pit will be treated by existing
stormwater facilities at the site. This project will increase flows to these stormwater
facilities; there will be the natural stream flows and stormwater runoff flows that have to be
managed. Please explain how these flows will be diverted to the existing stormwater
facilities? Please explain how the existing stormwater facilities are of a sufficient size to
handle these added flows while maintaining compliance with the Stormwater Permit
NCG020795 benchmarks and avoiding water quality standards violations?
Please provide your response in writing to the addresses below prior to September 28, 2012. Four copies of the
required information should be provided to the Wetlands, Buffers, Stormwater Compliance and Permitting Unit
at:
Ian McMillan
WeBSCaPe Unit
1650 Mail Service Center
Raleigh, NC 27699 -1650
and a single copy to the Asheville Regional Office at:
Linda Wiggs
Surface Water Protection Section
2090 US HWY 70
Swannanoa, NC 28778
If we do not hear from you by the deadline, we will assume that you no longer want to pursue this project and
we will consider the project withdrawn.
This letter only addresses the preliminary application review and does not authorize any impacts to wetlands,
waters or protected buffers. Please be aware that any impacts requested within your application are not
authorized (at this time) by the DWQ. Please call Linda Wiggs 828 - 2964500, if you have any questions.
Sincerely,
Chuck Cranford, Regional Supervisor
Surface Water Protection
Asheville Regional Office
cc Tasha McCormick - US Army Corps ot'Engineers Asheville Field Office
David McHenry - North Carolina Wildlife Resources Commission
Karen Higgins - WeBSCaPe l Init
DLR -ARO
ARO File copy
Clearwater Consultants (e -copy)
S \SW'P\A%en',401 s \Non- 1)01lUntmm Schoolhouse west Mme \Addlnfo Umtmn Schoolhouse 2012 doc