NCS000040 Draft Permit Cover Letter_signed

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. David Waggoner
Charlotte Pipe and Foundry Company
P.O. Box 35430
Charlotte, NC 28235
Subject: Draft NPDES Stormwater Permit
Permit No. NCS000040
Charlotte Pipe and Foundry Company
Mecklenburg County
Dear Mr. Waggoner:
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 from the previous permit. Monitoring is
proposed for Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), Total Copper (Cu), Total Lead
(Pb), Total Zinc (Zn) and pH. Based on monitoring results reported as well as the potential pollutants at
your facility the Division has determined that these parameters are appropriate for assessing potential
impacts from your discharge. Monitoring results from the previous permit cycle for Oil & Grease,
Chromium (Cr), Total Kjeldahl Nitrogen (TKN), Nickle (Ni) and Phenols have been consistently below the
benchmark values. 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 through
stormwater runoff.
Please note that for a number of the metals parameters the benchmark values have increased since the last
permit. The table below shows the changes.
Parameter
2009 Benchmark
(mg/L
2018
Benchmark(m /L)
Copper(Cu)
0.007
0.010
Lead Pb
0.030
0.075
Nickle Ni
0.260
0.335
Zinc Zn
0.067
0.126
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
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

NCS000040 Draft Permit
Page 2
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 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 2021.
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 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 NCS000040
cc: Zahid Khan, DEMLR Mooresville Regional Office - via email
Chad Broadway, Charlotte -Mecklenburg Stormwater Services - via email
Stormwater Permitting Program Files