NCS000597_Facility Draft Permit Response Letter_20210409

hdrinc.com
April 9, 2021
Ms. Aana Gamble via email at: aana.gamble anncdenr.gov
Division of Energy, Mineral and Land Resources - Stormwater
North Carolina Department of Environmental Quality
1612 Mail Service Center
Raleigh, North Carolina 27699-1612
Subject: Response Letter
Draft NPDES Stormwater Permit
Permit No. NCS000597
Galvan Industries
7315 Galvan Way, Cabarrus County, Harrisburg, NC
Dear Ms. Gamble,
On behalf of Galvan Industries, Inc. (Galvan), HDR Engineering, Inc. of the Carolinas
respectfully submits the following comments and questions for clarification to the draft
NPDES Stormwater Permit No. NCS000597 issued to Galvan on March 11, 2021. Based
upon our review of the draft permit, Galvan offers the following:
1. You are required to collect analytical and qualitative monitoring samples during
"measurable storm events" as defined in Part J. This term is different from the
"representative storm event" in earlier permits.
Galvan acknowledges and accepts the requirement to collect analytical and qualitative
monitoring samples during "measurable storm events," indicating that actual discharge
has occurred, as defined in Part J of the draft permit. Related to this requirement, in
Section D-3, outfall monitoring shall begin at least 48 hours after the previous
measurable storm event (sub -parts (a) and (d)), however, the definition states 72-
hours. Galvan asks that NCDEQ clarify the required minimum frequency between
measurable storm events.
2. Requirements for the Stormwater Pollution Prevention Plan (SWPPP) have been
updated in Part B.
Galvan acknowledges that Section B-10 (Conditions for Zinc Management) and
Section B-11 (Metal Removing SCMs) are new requirements for this site and will result
in an updated SWPPP from the current version.
440 S. Church Street, Suite 900; Charlotte, NC 28202
T 704.338.6700 F 704.338.6760

Ms. Aana Gamble
April 9, 2021
Page 2
3. Changes have been made to monitoring parameters and benchmarks for those
parameters. Stormwater benchmarks are not permit limits, but rather guidelines
for implementing the SWPPP. A benchmark exceedance is not a permit violation;
however, the permittee must respond to exceedances as directed in Part D.
Oil & Grease monitoring parameters have been revised as follows:
o 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 appliesto drainage areas where industrial activities use >55
gallons of oil, on average, per month. If the facility has any drainage areas in
which >55 gallons of oil are used during the permit cycle, the requirements
shall apply.
Galvan has noted the following changes to quantitative monitoring:
• The previous version of NCG030000 contained the requirement for analysis of
O&G using EPA Method 1664 (SGT-HEM) with a benchmark of 15 mg/L. Galvan
will review average monthly oil usage onsite and implement analysis of O&G/TPH
only if average usage exceeds 55 gallons per month.
• The draft permit now requires analysis for chemical oxygen demand (COD).
• The copper parameter code for reporting has changed from 01119 to C0665 and
the benchmark has changed from 0.010mg/L to 0.2 mg/L.
• The zinc parameter code for reporting has changed from 01094 to 01092, but the
benchmark has not changed.
• Total toxic organics (TTO) testing will no longer be required under the draft permit.
When initially discussed with Zahid Khan in 2019, Galvan understood that an
advantage of operating under an Individual Permit is that NCDEQ can establish site -
specific benchmark criteria that consider operations at the site; however, the
benchmark for the most commonly used parameter onsite (zinc) has not changed in
the draft permit. Was consideration given to zinc use onsite prior to setting the zinc
benchmark in the draft IP?
4. New requirements on reporting have been added in Part E to comply with federal
regulations requiring electronic submittal of discharge monitoring reports.
Additionally, this permit contains requirements forfuture reporting via eDMR
when the forthcoming eDMR internet application is finalized.

Ms. Aana Gamble
April 9, 2021
Page 3
Can NCDEQ please clarify the requirements for submittal of DMRs under this permit?
Per Table 5, it appears that DMRs for sampling conducted between January 1, 2021
and March 30, 2021 have a submittal deadline of January 31, 2022?
Additional Questions:
May Galvan utilize historical / previous analytical monitoring data to meet Section D-1
(Required Baseline Sampling) or does NCDEQ request a new dataset to commence
with this permit?
2. Prior to construction of the high-speed rail line in 2016, Galvan petitioned forand was
awarded representative outfall status for Outfall #2 on the site. During construction,
Galvan was concerned that earthwork and relocation of Outfall #2 approximately 50
feet east of its former location would have a negative impact on stormwater quality at
the outfall, and thus, has sampled other outfalls onsite. Galvan would appreciate the
opportunity to discuss with NCDEQ the potential to move back to representative outfall
status at Outfall #2.
Should you have any questions or need additional information, please contact Mark Filardi
at [phone] or Mark. Filardi(aDhdrinc.com.
Sincerely,
HDR Engineering, Inc. of the Carolinas
Mark P. Filardi, P.G.
Senior Geologist/Project Manager
Cc: James Moore, NCDEQ
Ed Watson, NCDEQ
Andrew Pitner, NCDEQ
Laurens Willard, Galvan
Laurens Y. Willard, Galvan
Harshad Londhe, Galvan
Peter McGrath, Moore & Van Allen