20171022 Ver 1_401_AddInfo_RutherwoodSS_20170913

Environmental Resources of the Carolinas, Inc.
72 Brownwood Avenue, Asheville, NC 28806

Carson Dellinger
Scientist/ Project Coordinator
[phone]
Carson [e-mail]

September 13, 2017

Sue Homewood
NC Division of Water Resources
Winston-Salem Regional Office

Re: Request for Additional Information on Blue Ridge EMC’s Rutherwood Substation, DWR#
20171022

Dear Ms. Homewood:

The following includes responses (R) to your September 6, 2017, request for more information on
the Rutherwood Substation application for 401 Water Quality Certification from the NC Division
of Water Resources (DWR).

“1. Page 10 of 10 carries the signature of Carson Dellinger. An agent authorization form was provided for
Carson Dellinger to represent Blue Ridge Electric Membership Corporation, however the applicant
identified on Page 2 of 10 is US Synergetic LLC. In order for Carson Dellinger to sign the application
package the Division requires an agent authorization letter from the applicant. [15A NCAC 02H .0506(f)]”

R: Two agent authorization forms were submitted through the “supplemental information” link
provided by NC DWR on September 11, 2017. One form authorizes representation by Carson
Dellinger of Environmental Resources of the Carolinas, Inc. of UC Synergetics, LLC. The other
form authorizes representation by UC Synergetics, LLC of Blue Ridge EMC.

“2. Per Condition II. 11 in GC 4086 “all culverts must be placed below the elevation of the stream bed by
one foot for all culverts with a diameter greater than 48 inches and 20 percent of the culvert diameter
for culverts having a diameter less than 48 inches.” Please revise your plans to meet this Condition or
request an exemption from this Condition and provide justification for the exemption request. [15A
NCAC 02H .0506(b)(2) and .0502(b)]”
R: Per the current design, we are only planning to install one culvert in a potential stream bed on
the western side of the proposed substation. This “stream” is fed by a small wetland from which
we are going to install a subsurface drainage system. The subsurface drainage system will capture
seepage from the existing wetland area and will be piped downhill to the point at which this
drainage has been DELINEATED as a stream. From this point, we will culvert the remaining
drainage channel to daylight. Therefore, we will have approximately 91 ft. of stream that will be
culverted within the fill embankment. Because this culvert will be subsurface, we do not feel the
need to bury the pipe per Condition II. 11 in GC 4086.
Additionally, the only other culverts to be installed will be under the station (for drainage of the
substation pad) and under the proposed access road, in two locations. Mitigation is planned for the
stream/wetland disturbance on the west side of the property and there are NO impacts anticipated
for the stream and wetland to the east side of the station. (Christopher Hopkins, Engineer II, UC
Synergetic, LLC)

“3. Per Condition II. 9 of GC 4086, all work must be done “in the dry”. Therefore, dewatering methods
will be necessary to temporarily dewater the stream channel during pipe installation. Please provide a
construction sequence that details the method of dewatering to be utilized at the site and the sequence
of construction events to be followed to ensure compliance with this condition. In addition, please
ensure that the location of the temporary impacts are shown on the construction drawings and clearly
indicated in a revised impact table (Table 3 of the PCN form). [15A NCAC 02H .0502(b)(3)]”

R:

Dewatering:

The dewatering system shall be of a sufficient size and capacity to control hydrostatic pressure in
all strata to a minimum of two (2) ft below any excavation. For fill areas, water shall be removed
to a minimum of one (1) foot below the grade prepared in accordance with the specifications to
accept earthen fill. Dewatering shall be of sufficient capacity to allow all material to be excavated,
earth fill placed and compacted and all subgrade piping and subsurface water collection systems
placed in a dry condition.

The Contractor shall control, by acceptable means, all water regardless of source. Water shall be
controlled and its disposal provided for in accordance with applicable federal, state and local
regulations. Disposal of the water shall be at no additional cost to the Owner.

Methods used to control surface and subsurface water include, but are not limited to, diversion
dikes, drainage swales, sumps, down drains, cutoff walls, observation wells, drainage blankets and
deep wells. In some instances, it may be necessary to install a wellpoint system to remove the
water from excavations to the depths described above. Should a wellpoint system be required, the
Contractor shall provide submittals to the Owner detailing the type of system to be used, number
of wells, capacity of the pumping system, layout of piping and other pertinent details as necessary
to fully describe the proposed system.

The dewatering system shall be designed using accepted and professional methods of design and
engineering consistent with the best modern practice. All surface and subsurface water removed
from the excavation and fill operations shall be diverted to an approved sediment trap(s) on site
prior to discharge to the environment. Direct discharges to the environment will not be permitted.
The Contractor shall monitor discharge locations on a daily basis to ensure that no erosion of the
soils occurs and that slopes remain stable during the dewatering operations. In no case shall water
that exhibits a sheen, contains oils or other deleterious substances or is otherwise contaminated be
discharged from the site.

Once the excavation or fill area is dry as defined above, the Contractor shall install the piping and
subsurface drainage. These systems shall be installed in accordance with the provisions found in
the appropriate sections of the plans and specifications.

Subsequent to completion and acceptance of all work, the Contractor shall maintain the excavation
in a dewatered condition and the water level at the specified and approved elevation until such
time as the work is complete.

Upon completion of the work and acceptance by the Owner, the Contractor shall remove all
dewatering equipment from the site, including related temporary electrical connections. All wells
shall be plugged and/or filled. (Joe Ervin, P.E., LEED-AP, UC Synergetic, LLC)

“4. Please clarify whether a riprap apron will be installed below the culvert outlet. If one is to be
included please provide clarification if these impacts were included in the permanent impacts listed as
“culvert” on Table 3 of the PCN form. [15A NCAC 02H .0502(b)]”

R: In accordance with the State’s Best Management Practices for erosion control, a rip rap apron
(aka - dissipator pad) shall be installed at the outlet of each proposed culvert. Once each pipe has
been properly sized and the flow rate has been determined, the length and width of each associated
rip rap apron will be established. (Christopher Hopkins, Engineer II, UC Synergetic, LLC)
Thank you for your assistance in processing this request. Please let me know if you have additional
questions or requests.

Best Regards,

Carson Dellinger