20180605 Ver 1_More Info Received_20180611

1. Provide a map depicting the extent of proposed dredging within the Grassy Creek
impoundment. The map shall include anticipated depths to be excavated relative to normal
pool elevation and any applicable staging areas. [15A NCAC 02H .0502(b)]
See enclosed Altapass Habitat Establishment Project, Overview of Dredge Operation and
Proposed Habitat Area
2. Describe how turbidity will be controlled in Grassy Creek during dredging activities to
maintain compliance with 15A NCAC 02B .0211 (21).
The following Best Management Practices will be utilized to maintain compliance with turbidity
standards in streams designated as trout waters. In active dredging areas sediment curtains will be
used to control resuspended sediments within the dredge area. All sediment and erosion control
measures will be continually monitored by onsite personnel. If needed to allow for equipment
access, sediment fencing and temporary matting will be used to prevent runoff from entering
Grassy Creek during dredging operations. Once dredging operations have been completed,
impacted soils and/or streambanks will be stabilized with native vegetation.
3. Describe how dredge spoils will be conveyed from Grassy Creek to the mine pit. For
instance, will the dredged slurry be pumped directly into the mine pit? Will it be de -
watered prior to being placed in the depression? If so, how? [15A NCAC 02B.0211(21)]
Hydraulically dredged spoils will be pumped directly to the habitat establishment area. Note that
the habitat establishment area will be dewatered prior to spoil placement. Flocculent will be
added to all dredged slurry to control turbidity in trout -designated receiving waters, and fill
progress will be monitored by personnel on-site. Excess water contained within the dredged
slurry will be controlled during active dredging and habitat establishment operations with a
skimmer that will gravity -drain through a flashboard riser to a plastic- or geotextile fabric -lined
flow path with coconut erosion control wattles and into the North Toe River after flocculent -
driven settlement of particulates has occurred. Water quality will be monitored for the duration of
the project, and dredging operations will cease if discharge water exceeds turbidity standards.
The OHWM of the habitat establishment area will be permanently controlled with a flashboard
riser and weir boards to maintain an 85:15 ratio of dredged fill to open water; excess stormwater
runoff accumulating within the habitat establishment area will gravity -drain via flashboard riser
through a plastic- or geotextile fabric -lined flow path with coconut erosion control wattles into
the North Toe River.
4. Collect and analyze the water sample from the mine pit as described in the Pre -
Construction Notification and provide the laboratory analytical results to me, Linda Wiggs
(Linda.Wiggs(a)ncdenr.gov), and Shawna Riddle (Shawna.Riddle(a),ncdenr.gov). The
analyses shall be performed by a North Carolina certified laboratory. [15A NCAC 02B
.0211]
A report of analysis conducted by ETS-Asheville will be forwarded to all parties once received.
5. Provide a sediment sampling and analysis plan for the proposed dredge material. The
sediment sampling and analysis plan should be developed in accordance with the EPA's and

US Army Corps of Engineers' Evaluation of Dredged Material Proposed For Discharge In
Waters Of The U.S.-Testing Manual (https://www.epa.gov/sites/production/files/2015-
08/documents/inland testing manual O.pdf). Note that the dredged material may be
considered a beneficial fill (15A NCAC 13B .0562) under Division of Waste Management
(DWM) rules and must meet their requirements prior to placement in the mine pit. I
recommend you contact Ervin Lane (919-707-8288 or ervin.lane(ancdenr.gov) to determine
the analyses required by the DWM. [15A NCAC 02H .0506(b)(3)]
Samples taken from the proposed dredge area of Grassy Creek have been sent to ETS-Asheville
for analysis. Results will be forwarded to all parties once received.

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Establishment Area
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Dredge Area Limit: ~0.85 Acres
Anticipated Excavation Depth Limit: :M'
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