SW6180702_AddInfo3_ACP Fayetteville_20180906

September 6, 2018

Leslie Hartz, Vice President - Pipeline Construction
Dominion Energy Transmission, Inc.
5000 Dominion Blvd.
Glen Allen, VA 23060

Subject: Request for Additional Information
Stormwater Permit No. SW6180702
ACP Fayetteville Contractor Yard – CY10a
Cumberland County

Dear Ms. Hartz:

The Division of Energy, Mineral and Land Resources (DEMLR) received a Stormwater Management
Permit Application for the subject project on July 20, 2018 and additional information via telephone on
August 22, 2018 and supplemental documentation on September 6, 2018. A review of the application has
determined that additional information is needed to meet the requirements of 15A NCAC 02H . Failure to
provide the following additional information to DEMLR by October 6, 2018 will result in the application
being returned as incomplete. If the project is returned, then a resubmittal of all required items is required,
including the application fee.

Please address the following plan deficiencies:

1. Non-Erosive Outlets [Ref. 15A NCAC 02H .1050(4)]: The outlets of SCMs shall be designed so
that they do not cause erosion downslope of the discharge point during the peak flow from the 10-
year storm event as shown by engineering calculations. Provide calculations.
2. Non-Erosive Inlets [Ref. 15A NCAC 02H .1050(4)]: The inlets of SCMs shall be designed to
protect the SCM from erosion resulting from stormwater discharges. Provide design details and
supporting calculations.
3. Conversion to Wet Pond [Ref. 15A NCAC 02H .1050(7)]: Every SCM impacted by
sedimentation and erosion control during the construction phase shall be cleaned out and
converted to its approved design state. Provide appropriate construction sequence on plans.
4. Maintenance Access [Ref. 15A NCAC 02H .1050(8)]: Every SCM installed pursuant to this
Section shall be made accessible for maintenance and repair. Maintenance accesses shall: (a) have
a minimum width of ten feet; (b) not include lateral or incline slopes that exceed 3:1 (horizontal
to vertical); and (c) extend to the nearest public right-of-way. Please provide a separate plan
sheet showing the SCM maintenance easement. It is difficult to see on the submitted plans.

5. Vegetation Plan [Ref. 15A NCAC 02H .1053(11)]: The dam structure, including front and back
embankment slopes, of the pond shall be vegetated with non-clumping turf grass; trees and
woody shrubs shall not be allowed; and the vegetated shelf shall be planted with a minimum of
three diverse species of herbaceous, native vegetation at a minimum density of 50 plants per 200
square feet of shelf area. Provide an appropriate planting plan and include planting in the
construction sequence.
6. Forebay Design [Ref. 15A NCAC 02H .1053(5)]: The forebay entrance shall be deeper than the
forebay exit; If sediment accumulates in the forebay in a manner that reduces its depth to less
than 75 percent of its design depth, then the forebay shall be cleaned out and returned to its
design state. Include appropriate information on the construction drawings and Operation and
Maintenance Plan.
7. Forebay Design [Ref. 15A NCAC 02H .1053(5)]: The water flowing over or through the
structure that separates the forebays from the main pools shall flow at a nonerosive velocity.
Provide supporting documentation to confirm this.
8. Other plan deficiencies that must be resolved in order to perform a final review include:
a. Show location of riser structures.
b. Provide invert on pipe inlet to Wet Pond 222.
c. Provide SCM construction sequence, including conversion from sediment basins and
required SCM planting plan.
d. Calculations included HRT for main pool volume and SA/DA method for average depth.
Only one method should be used. With HRT, average depth should be computed
utilizing Equation 2 or 3 in the Stormwater Design Manual [Ref. page 8, C-3 Wet Pond].
e. Sheet 4 of 9 Basin Riser Detail table shows outlet u/s inv at 90.75 for Wet Pond 222, plan
sheet shows 91.0.
f. It is unclear how flow from the proposed (2) 18” culverts located north of Wet Pond 221
will be directed to the forebay.
g. The note below the Basin Riser Detail table should indicate that the NCDEQ Erosion and
Sediment Control Manual and the Stormwater Design Manual are two separate
documents and both must be followed.

Please reference the State assigned project number SW6180702 on all correspondence. If you need
additional time to submit the information, please submit your request for a time extension to the Division
at the contact below. The request must indicate the date by which you expect to submit the required
information. The Division is allowed 90 days from the receipt of a completed application to issue the
permit.

The construction of any impervious surfaces, other than a construction entrance under an approved
Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject to enforcement
action pursuant to NCGS 143-215.6A.

If you have any questions concerning this matter please feel free to contact me at
[e-mail] or [phone].

Sincerely,
Jeanette Powell
Environmental Engineer
Stormwater Program

Cc: Staci Roggi, Dominion Energy
Richard Gangle, Dominion Energy
Mr. Scott A Robinson, PE, ERM NC, Inc.
DEMLR Fayetteville Regional Office