NCS000255_Grede Cover Letter_20170620

Energy, Mineral
and Land Resources
ENVIRONMENTAL QUALITY
ROY COOPER
Governor
MICHAEL S. REGAN
secrermy
'RACY DAVIS
Director
June 20, 2017
Mr. Jamie Burger
Grede II, LLC
P.O. Box 748
Biscoe, NC 27209
Subject: Draft NPDES Stormwater Permit
Permit No. NCS000255
Grede II, LLC
Montgomery County
Dear Mr. Burger:
Enclosed with this letter is a copy of the draft stormwater permit for your facility. Please
review the draft carefully to ensure thorough understanding of the conditions and
requirements it contains.
The draft permit contains the following significant changes from the facility's current permit:
1. You are required to collect analytical and qualitative monitoring samples during
"measurable storm events" as defined in Part I1, Section B. This term is different
from the "representative storm event' in earlier permits.
2. Requirements for the Stormwater Pollution Plan (SPPP) have been updated in Part II,
Section A.
3. Changes have been made to three monitoring parameters, including changes to two
benchmarks. Stormwater benchmarks are not permit limits, but rather guidelines for
implementing the Stormwater Pollution Prevention Plan (SPPP). A benchmark
exceedance is not a permit violation; however, the permittee must respond to
exceedances as directed in the Tiers.
Non -polar Oil & Grease [EPA Method 1664 (SGT -HEM)] replaces Oil &
Grease to better represent potential discharges at a facility storing only
petroleum-based fuel oils (as opposed to non -petroleum-based fuel oils). The
benchmark for Non -polar Oil & Grease using this method is 15 mg/L.
• Monitoring for Zinc has been removed from your permit because this
constituent is not used in this facility's industrial processes.
State of North Carolina I Environmental Quality I Energy, Mineral and Laud Resources
1612 Mail Service Canter 512 North Salisbury Skeet I Raleigh, NC 27699-1612
919 707 9200 T

• Monitoring for Total Kjeldahl Nitrogen has been removed from your permit
because in multiple years of monitoring, levels have been consistently well
below the benchmark.
• The benchmarks for the following parameters have been revised to reflect
current water quality standards:
o Copper benchmark is increased from .007 mg/L to .010 mg/L;
o Cadmium benchmark is increased from .001 mg/L to .003 mg/L;
o Lead benchmark is increased from .03 mg/L to .075 mg/L; and
o Nickel benchmark is increased from .26 mg/L to .335 mg/L.
Vehicle maintenance (Tables 5,6) monitoring parameters have been revised
as follows:
o Non -Polar Oil & Grease [EPA Method 1664 (SGT -HEM)] replaces
Oil & Grease/TPH. This requirement appears in all individual
stormwater permits; however, it only applies to facilities that
perform onsite vehicle maintenance activities. If the facility begins
vehicle maintenance during the permit cycle, the requirements shall
apply.
o pH monitoring is no longer required for discharges only associated
with vehicle maintenance activities.
4. Tiered responses have been added to this permit. Exceedances of benchmark values
require the permittee to increase monitoring, increase management actions, increase
record keeping, and/or install stormwater Best Management Practices (BMPs) in a
tiered program in accordance with Part 11, Section B of this permit.
5. A new section on Special Conditions has been added in Part II, Section E to comply
with federal regulations requiring electronic submittal of discharge monitoring
reports. This section of the permit became effective December 21, 2016.
6. Civil and administrative penalty amounts have been updated to reflect current
federal law in Part III, Section A, 2(b) and (g).
7. Representative Outfall Status has not been granted for this facility. As such, you
must perform the required analytical monitoring at all Stormwater Discharge Outfalls
(SDO). Previous inspections by DEQ staff indicated that SDO #2 was not being
monitored and that SDO #3 (alleyway) was being used to represent SDO#2. Unless
DEQ staff grants approval of Representative Outfall Status, you must monitor all
SDOs, including SDO#2. In addition, note that qualitative monitoring shall continue
to be required at all SDOs, even if Representative Outfall Status is granted in the
future.
8. The following laboratory data reporting issues must be addressed:
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• Lab reports submitted to DEQ have erroneously labeled SDO#3 (alleyway) as
SDO42. Please refer to the facility site map for proper identification of each
SDO.
• Lab results for phenols have been reported in the incorrect units. Please
ensure that lab results for all parameters are reported in the units specified in
the permit (mglL).
• For cadmium, the reported minimum detection limit appears to be above the
benchmark. Please ensure that the laboratory's minimum detection limit for
cadmium and all other parameters are at or below the benchmarks specified in
the permit.
Please review the draft permit and submit any comments to me no later than 30 days
following your receipt of the draft. Comments may be emailed to me at
julie.ventaloro &ncdenr. og_v or mailed to my attention at NC DEMLR, Stormwater
Permitting Program, 1612 Mail Service Center, Raleigh, NC 27699-1612. If you have any
questions, please email me or call me at [phone].
Sincerely,
i
Julie Ventaloro
Stormwater Permitting Program
Attachment: Draft Permit NCS000255
cc: Lorenzo Jackson, Grede II, P.O. Box 748, Biscoe, NC 27209
Mike Lawyer, DEMLR Fayetteville Regional Office
Stormwater Permitting Program Files
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