20080868 Ver 2_DEMLR Add Info for R-5 Dike Breach_20171201

ROY COOPER
%*a
Governor
MICHAEL S. REGAN
..
Secretary
Energy, Mineral
TRACY DAVIS
and Land Resources
ENVIRONMENTAL QUALITY
Director
December 01, 2017
Robert Chiles Engineering
Attn: Mr. Robert M. Chiles, Jr., PE
417- A Broad Street, P.O. Box 3496
New Bern, North Carolina 28564
DEC -
RE: PCS Phosphate R-5 Dike
Beaufort County
State Dam ID: BEAUF-012
Dear Mr. Chiles:
A review has been made of the plans, and design data which was received in this office October 13, 2017, for the
breach of the referenced high hazard dam. Prior to issuance of an approval to breach, additional information or
revision is requested for the following items:
1. Please review time of concentration methodology for this particular project based on the drainage area. It is
recommended to use HEC HMS, HEC RAS etc. software to provide the design detailingtreport.
2. Please clarify on the rainfall distribution type that has been considered for this particular project. On page
03/06 under hydrology and under summary, literature confirms using of SCS Type III distribution but
hydrograph report on page 04 shows use of distribution Type II.
3. Please provide more cross sections detailing at the bend section of the armored breach channel plan, profile
on drawing no: 2017409 P- 5. All the drawing details needs to be sealed and signed with current dates.
It would greatly aid further application review ifa response to above comment were made in a cover letter
submitted with two sets of the revised plans, specifications and design data (all electronic and hardcopies along
with softcopies of the models/simulation).-- ---
Please contact this office should you have any questions concerning the above items.
Since ely,
�.�K
Y.A. arif, PhD
Assistant State Dam Safety Engineer
Land Quality Section
cc: PCS Phosphate Company, Inc.
Mr. Samir Dumpor, PE, CPM, Land Quality Regional Engineer, WaRO
Surface Water Protection Regional Supervisor
Filename: BEAUF-012-20171201_revreq_PCS Phosphate R-5 Dike
State of North Carolina I Environmental Quality I Energy, Mineral, and Land Resources
1612 Mail Service Center I Raleigh, North Carolina 27699
919 707 9220 T