NCS000304 Draft Permit Cover Letter

Energy, Mineral
and Land Resources
ENVIRONMENTAL QUALITY
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
WILLIAM E. (TOBY) VINSON, JR.
Interim Director
September 19, 2018
Mr. Bob Churchill
Gerdau Ameristeel US, Inc.
Charlotte Mill
6601 Lakeview Road
Charlotte, NC 28269
Subject: Draft NPDES Stormwater Permit
Permit No. NCS000304
Gerdau Ameristeel US, Inc.
Mecklenburg County
Dear Mr. Churchill:
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:
You are required to collect analytical and qualitative monitoring samples during "measurable
storm events" as defined in Part II, Section B. This term is different from the "representative storm
event" in earlier permits.
Requirements for the Stormwater Pollution Plan (SPPP) have been updated in Part II, Section A.
Monitoring requirements in the draft permit have changed slightly from the previous permit.
Monitoring is proposed for Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), Total
Zinc (Zn), Total Aluminum (Al), Cadmium (Cd), Total Copper (Cu), Total Lead (Pb), Total Zinc (Zn)
and pH. Monitoring reported in your renewal application and additional information showed
results for Chromium (Cr), Nickle (Ni), Biological Oxygen Demand (BOD) and Oil and Grease (0&G)
below the benchmark level over the last five years. The draft permit proposes to remove these
parameters from the permit. Comments from our regional staff or other information may result in
maintaining these parameters or adding other parameters if it is apparent that your activities in
some way have the potential to release them at levels of concern through stormwater runoff.
Stormwater benchmarks remain in the permit as before. Keep in mind that 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. The draft permit has modified the tiered response process for benchmark
exceedances consistent with other permits in our program. Please become familiar with the tiered
process as proper response under the tiers may be enforceable items under your permit. Response
to the tiered process may include review of onsite conditions, installation of BMPs or requirements
for more frequent monitoring.
State of North Carolina I Environmental Quality I Energy, Mineral and Land Resources
1612 Mail Service Center 1 512 North Salisbury Street I Raleigh, NC 27699-1612
919 707 9200 T

NCSO003O4 Draft Permit
Page 2
4. Vehicle maintenance (Tables 4 & 5) monitoring parameters have been revised. Non -Polar Oil &
Grease [EPA Method 1664 (SGT -HEM)] replaces Oil & Grease/TPH. The benchmark for Non -polar
Oil & Grease using this method is 1S mg/L. 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. Also,
pH monitoring is no longer required for discharges only associated with vehicle maintenance
activities.
The vehicle maintenance language in the permit has also been modified to clarify that these
activities include not just vehicles, but also other similar equipment maintenance activities that
may be exposed to stormwater. This has always been the Division's implementation of this
requirement, but hopefully the adjusted language is a little clearer about this process.
5. Language has been added under Part II Section D to address potential responses to qualitative
monitoring issues.
6. 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. Our electronic
submittal process is not available for use at this time, but we will continue to provide feedback on
when this process will be available.
7. Civil and administrative penalty amounts have been updated to reflect current federal law in
Part III, Section A, 2(b) and (g).
8. The definition of Bulk Storage of Liquid Materials was revised in Part IV Definitions to omit the
language "located in close proximity to each other" as it applies to multiple above ground storage
containers having a combined storage of 1,320 gallons.
9. To address workload issues in the Stormwater Program we are working to have similar numbers of
individual permits for renewal over each of the next five years. In order to accomplish this some of
our permit renewals will be issued for time periods shorter than the usual five year cycle. Your
permit renewal is proposed to expire in 2 02 1.
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 bradley.bennettoncdenr.gov or mailed to my
attention at NC DEMLR, Stormwater Permitting Program, 1612 Mail Service Center, Raleigh, NC 27699-
1612. With this notification the Division will solicit comment on this draft by publishing a notice in a local
newspaper. Following the 30 day public comment period, the Division will review comments and take
appropriate action prior to issuance of the final permit.
If you have any questions, please email me or call me at [phone].
Sincerely,
Original Signed by Bradley Bennett
Bradley Bennett
Stormwater Permitting Program
Attachment: Draft Permit NCSO0O304
cc: Zahid Khan, DEMLR Mooresville Regional Office - via email
Chad Broadway, Charlotte -Mecklenburg Stormwater Services - via email
Stormwater Permitting Program Files