NCS000312 Draft Permit Cover Ltr_signed

Energy, Mineral
and Land Resources
ENVIRONMENTAL QUALITY
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
WILLIAM E. (TOBY) VINSON, JR.
lnterin Dlrecrar
June 11, 2018
Scott Madix
DART Acquisitions, LLC
4132 Pompano Road
Charlotte, NC 28216
Subject: Draft NPDES Stormwater Permit
Permit No. NCS000312
DART Acquisitions, LLC
Mecklenburg County
Dear Mr. Madix:
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 II, 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. Monitoring requirements in the draft permit have not changed from the previous permit.
Monitoring is maintained for Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), and
PH. Comments from our regional office staff or other information may result in adjustments to
these requirements if it is apparent that your activities in some way may have the potential to
release other parameters.
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.
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 15 mg/L. This requirement appears in all individual stormwater
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

NCS000312 Draft Permit
Page 2
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.
Please review the draft permit and submit any comments to me no later than 30 days following your
receipt of the draft. Comments maybe emailed tome at [e-mail] 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,
1 1 /
Bradley Bennett
Stormwater Permitting Program
Attachment: Draft Permit NCS000312
cc: Zahid Khan, DEMLR Mooresville Regional Office — via email
Chad Broadway, Charlotte -Mecklenburg Stormwater Services —via email
Stormwater Permitting Program Files