20190035 Ver 1_WRC Comments_20190910

1�1 North Carolina Wildlife Resources Commission 0
Gordon Myers, Executive Director
MEMORANDUM
TO: David Shaeffer and Catherine Janiczak
U.S. Army Corps of Engineers
FROM: Olivia Munzer, Western Piedmont Coordinator
Habitat Conservation
DATE: 10 September 2019
SUBJECT: Individual Permit Application for Piedmont Lithium Mine Project in Bessemer City,
Gaston County — Response to Comments; USACE Action ID: SAW -2018-01129; DEQ
Project No. 20190035.
Biologists with the North Carolina Wildlife Resources Commission (NCWRC) have reviewed the subject
document. Comments are provided in accordance with provisions of the Clean Water Act of 1977 (as
amended) and Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661-667e).
HDR, Inc., on behalf of Piedmont Lithium Inc. (applicant), has submitted an Individual Permit (IP)
application for the proposed Piedmont Lithium Mine centered around 1501 Hephzibah Church Road in
Bessemer City, Gaston County, North Carolina. On 03 July 2019, the applicant submitted responses to
comments on the IP and the Public Notice to the U.S. Army Corps of Engineers (USAGE). The
responses included changes to the site acreage and impacts to jurisdictional waters, and the submission of
the groundwater modeling report. The site is now 963 acres, which is a reduction of 8 acres from the
southwestern corner of the site. The impacts would total 0.18 acre (ac) of wetlands, 0.16 ac open water,
1,481 linear feet (If) of perennial streams, and 4,904.5 if of intermittent streams. The additional impacts
are from the proposed fill severely degrading the function of the remaining wetland and isolation of the
wetland from the downstream waters (Impact 14); the greater pit area causing the realignment of the
internal road and magazine (Impact 2); greater pit extension (Impact 6); and additional impacts for two
erosion control structures (Impact 18 and 9). According to the applicant's response to IP comments, the
proposed site layout avoids impacts to Beaverdam and Little Beaverdam Creeks and their floodplains.
Based upon the response to comments and groundwater modeling report, we offer the following
additional recommendations to minimize impacts to aquatic and terrestrial wildlife resources.
We recommend moving or reconfiguring the erosion control structures to avoid or minimize
impacts to streams.
Mailing Address: Habitat Conservation Division • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] • Fax: [phone]

Page 2
10 September 2019
Piedmont Lithium Mine IP
USACE Action ID: SAW -2018-01129
2. The Groundwater Modeling Technical Memorandum (pg. 2) states that the base flow to three
streams crossing the site will decrease between 0.01 to 10 percent, depending upon the proximity
of the stream to the pit being dewatered. The greatest decrease will be to Little Beaverdam Creek
when the Central Pit is dewatered. The dewatering rate will be greatest for the Central Pit,
followed by East, North, and South Pits. Return water withdrawn will be discharged at points at
the downstream end of the Site. According to the additional response to comments, as many as
two pits will be opened at any time, and the current mine sequence will be East Pit, South Pit,
Central Pit, then North Pit. The Response to Comments (pg. 13) states that "any indirect impacts
as a result of pit dewatering are temporary in nature — once dewatering ceases, the groundwater
will recharge". The mine is expected to be operational for at least 11 years.
We understand the hydrogeological model presents the greatest amount of drawdown or
withdrawal at full excavation limit of each pit. However, we have concerns on the indirect
impact of the operation on the streams, in addition to the wetlands, based upon the statements
mentioned above and that dewatering is more or less continuous during operation. The Technical
Memorandum or Response to Comments do not address the amount of dewatering when pits are
operational simultaneously. We are concerned that if two pits are operational at once, that
dewatering could decrease the base flow more than 10 percent (the greatest amount of drawdown
per pit), particularly during drought years. Additionally, the aquifer may not recharge at the rate
of dewatering, particularly during drought years and/or if two pits are operational over a span of
11 years. The return water withdrawn during operation will be discharged downstream of the
site; therefore, we are concerned the portion of the streams within the site may dry up or be
abnormally low, which would indirectly impact aquatic resources.
Although there will be no direct impacts to Little Beaverdam Creek and Beaverdam Creek, there
may be potential indirect impacts to these streams. NCWRC knows of at least two undescribed
species of crayfish, one of which is likely a South Fork Catawba River endemic, and the
significantly rare Carolina foothills crayfish (Cambarus johni) in the Beaverdam watershed.
Since the impact of dewatering will likely impact stream flow, we request surveys for crayfish at
the site. For questions, please contact W. Thomas Russ, the Foothills Aquatic Wildlife Diversity
Research Coordinator, at 828-659-3324 or [e-mail].
As such, we recommend avoiding or minimizing the dewatering the Central and East Pits
simultaneously with other pits to decrease the rate of dewatering. Furthermore, we recommend
compensatory mitigation for the potential indirect impacts to streams that may occur from
dewatering activities.
3. We recommend that water quality, and perhaps surface flow, are monitored downstream of the
discharge point.
4. The outflows (energy dissipaters) should be located outside the recommended stream buffers;
minimum 100 -foot for perennial streams and a 50 -foot for intermittent streams and wetlands.
Thank you for the opportunity to comment. For questions or comments, please contact me at (919) 707-
0364 or olivia.munzerkncwildlife.org.
ec: Sue Homewood, NC Division of Water Resources (NCDWR)
Alan Johnson, NCDWR
Byron Hamstead, U.S. Fish and Wildlife Service
W. Thomas Russ, NCWRC
Chris Goudreau, NCWRC
Kelly Thames, HDR
Todd Bowers, U.S. Environmental Protection Agency