NC0000353_DEMLR SW_N Toe River Mines_20200410

NC DEMLR Stormwater Program
Current Status and Future Plans for the North Toe River Mines
DEMLR plans to work with the North Toe River mines to:
1) Continue to document corrective actions taken by the facilities in case of a benchmark/limit
exceedance;
2) Continue to provide assistance to ensure water quality standards are met; and
3) Pursue permitting that better fits mining facilities/conditions.
Only four out of the six mines of concern to DWR have stormwater permits, see the chart below:
SW Permit# WW Permit# Owner Name Facility Name
NCG020793 NC0000175 Sibelco North America Sibelco North America -Quartz Facility(aka Hawkins)
NCG020274 NC0000400 The Quartz Corp USA Pine Mountain M&P
NCG020818 NC0000353 The Quartz Corp USA Altapass Mine& Plant
NCG020795 NC0000361 Sibelco North America Sibelco North America -Schoolhouse Quartz Facility
NA NC0084620 Sibelco North America Crystal Operation
NA NC0085839 Sibelco North America Red Hill Quartz Processing Plant
Documentation and Corrective Actions
The four North Toe River mines with stormwater permits (listed above) were inspected July 2019. As a
part of this initiative, DEMLR ARO staff have been in contact with the North Toe River mines on a
monthly basis, helping the facilities address changes in the site that could affect water quality.
As a result of these inspections and conversations with DEMLR ARO staff,the Quartz Corp has made the
following improvements pertinent at both of its mine sites:
- All mine haul roads have been graveled with rock that will stand up to heavy haul trucks and will
not easily break down and deposit into the ditches to the sediment basins.
- An alternative method of settling sediment is being used to settle out fine particles and mica in
the water from basins with "semi continuous"flow—for example,the basin that captures the
water from the crusher plant (gate basin) is being implemented with a Lamella Settler.This type
of settler is designed to remove particulates from liquids. The mines are using a series of
inclined plates that provide a large effective settling area for a small footprint.Testing results
from the lamella demonstrates that the concept works.The turbidity of the effluent was
lowered from 13 to 3 NTU.
In addition,the following improvements have been made at the Pine Mountain mine:
- The haul road at the North end of the mine has been improved by capturing spring water before
it can cross over the haul road preventing sediment being transported off the haul road. Check
dams and water breaks were added to the ditch line.
- The PWST-5 basin has been reconfigured to capture water from the haul road before
discharging off property.
- The PMT-ST-4—tailing valley fill sediment trap—riser (standpipe) has been replaced and then
the riser(standpipe) has been encapsulated with wash W and 3/8" rock to filter water before
discharging off property.

At Pine Mountain #5, the upper pond has been upgraded to allow water to settle and discharge
into#5 lower.
Material covering and grass planting is being done on the completed slope of the tailing facility
to minimize the exposure of"tailing"to stormwater.
DEMLR staff are continuing to:
- Identify items pertaining to implementation of the SWPPP that that need attention.
- Document compliance status and corrective actions facilities are taking to address concerns with
mining permit conditions.
- Address exceedances of benchmarks and limits.
These efforts are ongoing and will continue to advance as additional inspections are performed and
monitoring data is collected.
NCG020000 Mining General Stormwater Permit
The Mining General Stormwater Permit expires on September 30, 2020. DEMLR has begun the public
input process for updating the permit conditions for this general permit. One of the changes that will
occur is that monitoring requirements for all mines will be provided within the permit rather than as an
addendum to the permit. There are several potential ways DEMLR might address this, including:
- Issue individual permits to each of the North Toe River mines;
- Provide pertinent monitoring requirements within the updated NCG02 permit; or
- Create a new mining general permit for these types of facilities that includes the pertinent
monitoring requirements.
DEMLR staff is still discerning the best approach for permitting these facilities going forward. The
monitoring results from the North Toe River mines thus far have provided DEMLR with valuable data
points that will allow DEMLR to better consider permitting needs suited to these mining facilities.
DEMLR is also considering how best to improve the permit conditions, monitoring and reporting
necessary to better address issues that have been identified in these mines.