20210428_NCDMF Comment_Foster Forbes Mine

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
JOHN G. BATHERSON
Acting Director
MEMORANDUM:
TO: Adam Parr, NCDEMLR Assistant State Mining Engineer
FROM: James Harrison, NCDMF Fisheries Resource Specialist
SUBJECT: Foster Forbes Mine, Currituck County
DATE: 28 April 2021
A North Carolina Division of Marine Fisheries (DMF) Fisheries Resource Specialist has
reviewed the mining permit application for proposed actions that may impact fish and fish
habitats. The applicant is proposing to mine sand and topsoil near 8180 Caratoke Highway,
Powells Point, within Currituck County, North Carolina. The applicant is requesting an 8-
year permit, and proposes development of a new 6.23-acre mine (on 41 acres of land),
excavating to an average depth of 30' below ground level, with a 35' maximum depth. The
existing 0.51-acre pond, located 85' east of the proposed excavation boundary, will be
utilized as a sedimentation pond for dewatering during the excavation. In order to dewater
during operation, the applicant proposes to install a pump at the south end of the sediment
pond; discharge from the pump will flow 320 feet north to an existing stream, then an
additional 0.7 miles to the Albemarle Sound. As described below, the specifics of the
dewatering involved with this project are unclear. The applicant is also proposing to
construct a 1,260' long by 10' wide ditch between the proposed excavation and the
adjacent wetlands located 75' westward from the mine. This ditch will be kept artificially
full by having water pumped into it from the excavated pond.
DMF is concerned about the potential impacts to nearby habitats that may occur as a result
of the proposed project. The proposed dewatering involves drainage to nearby wetlands
and the Albemarle Sound. There is a record of submerged aquatic vegetation (SAV) along
the shoreline within the Sound. The water that will pass through the wetlands and into the
Sound may cause alterations in salinity that could cause a loss of SAV and/or wetlands, and
could cause conditions unsuitable for revegetation. Furthermore, the loss of these habitat
types could impact the various species that utilize these habitats for forage, refuge, and/or
nursery area. Additionally, these impacts could reduce the natural shoreline stabilization,
nutrient reduction, and water quality stabilization/improvement capabilities that these
habitats provide.
State of North Carolina Division of Marine Fisheries
3441 Arendell Street I P.O. Box 769 Morehead City, North Carolina 28557
252-726-7021

The applicant included weekly monitoring of the ditch that flows to the wetlands for
evidence of sedimentation or erosion, as well as quarterly monitoring for suspended solids,
settleable solids, turbidity, pH, chlorides, and flow rate. DMF would recommend obtaining
baseline data prior to the commencement of mining activities. Ideally, this would've began
at least one year prior to mining beginning, as that would provide sufficient time to observe
and record the daily, weekly, monthly, and annual variations of these water quality
parameters. However, obtaining this data prior to commencement of activities would at
least provide some degree of baseline data. DMF would also recommend more frequent
sampling of water quality, as only sampling quarterly can allow significant alterations to
nearby areas to occur unnoticed for extended periods. Water quality could be sampled
simultaneously with the ditch/wetlands monitoring. DMF is also concerned about the lack
of specific limits for water quality sampling parameters (i.e. a maximum allowable pH), as
well as the lack of reporting/reacting requirements when sampling shows a violation of
those restrictions. For example, there was no indication of an allowable pH range or what
actions would be required in the event that sampling data shows a level above or below
that range. DMF recommends that a management plan be developed that details specific
water quality limitations, as well as specific measures to be taken should sampling results
indicate variation outside of allowable levels.
DMF would also like to note inconsistencies in the application package provided. On page 8
of the document (Section C. Protection of Natural Resources, item 1, bullet i., or C.1.i.), it is
indicated that the dewatering pump running at idle speed would result in a flow rate of
400-500 gallons per minute (GPM) into the sediment pond, and page 10 (C.3.c.) notes an
estimated withdrawal rate of 0.24 million gallons per day (MGD). However, page 43 in the
Dewatering Procedure section, it is noted that the pump would be operating at idle speed,
and would result in a maximum flow from the pump of 2,000 GPH resulting in a withdrawal
rate of 0.024 MGD. The flow rate of 400-500 GPM would translate to 24,000-30,000 GPH,
or 288,000-360,000 GPD (assuming 12 hours of operation per day). These are significant
differences in per minute, per hour, and per day rates, and could result in substantially
different impacts, particularly to the surrounding wetlands. Also, the length of the life of
the permit is unclear, as page 6 indicates an 8-year life for the mining permit, but page 45
indicates a 6-year permit for dewatering. These inconsistencies should be addressed, and
resource agencies should be notified of the correct values prior to permit issuance, as these
could impact the assessments and cause changes to the comments/recommendations
provided.
There are also numerous instances of other mining operations being mentioned. For
example, the description of the temporary swale construction indicates that this structure
is intended to ensure hydration of wetlands adjacent to the permit boundary of the Marty
Hurdle sand mine. Additionally, the description of this measure does not appear to match
the site plans provided, and either the description or plans should be adjusted to accurately
describe/portray this measure. It is also unclear how this structure will be kept full of
water during dewatering, as the only pumps involved are from the mine to the pond, and
the pond to the discharge pipe. Also, the water height control on page 32 mentions that the
structure will be installed at the Mary L. Sawyer mine, with outflow to the Pasquotank
River.
State of North Carolina Division of Marine Fisheries
3441 Arendell Street I P.O. Box 769 Morehead City, North Carolina 28557
252-726-7021

DMF is concerned about the potential significant adverse impacts that may arise as a result
of this project. Based on what has been provided, DMF cannot adequately and accurately
assess the potential impacts of this project. No information was provided on the potential
impacts to local fisheries or habitats (specifically, surrounding wetlands and SAV within the
Sound), there was no explanation of any dewatering discharge alternatives being
considered, no information was provided on measures to be taken if conditions don't meet
expectations during monitoring, and there were inconsistencies throughout the
application, some of which have been detailed above. Until this information is received,
DMF will be unable to conduct a complete review of the project.
Thank you for consideration of our comments. Please contact Jimmy Harrison at (252)
948-3835 (office) or [phone] (mobile - preferred), or at
james.harrisonOncdenr.gov with any further questions or concerns.
State of North Carolina Division of Marine Fisheries
3441 Arendell Street I P.O. Box 769 Morehead City, North Carolina 28557
252-726-7021