NCS000304_Draft Permit_20090309

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NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins
Governor Director
March 9, 2009
Mr. Anthony S. Read
Gerdau Ameristeel US Inc.
PO BOX .481980
Charlotte, North Carolina 28269
Subject: Draft NPDES Stormwater Permit
Permit No. NCS000304
Gerdau Ameristeel US Inc.
Mecklenburg County
Dear Mr. Read:
Dee Freeman
Secretary
Enclosed with this letter is a copy of the draft stormwater permit for your facility. Please review the draft
very carefully to ensure thorough understanding of the conditions and requirements it contains.
Outfall 001 has been removed from the monitoring as asked for in the representative outfall letter with the
renewal package because the area is an employee parking that is elevated from industrial activates.
However, the other request in the representative outfall letter for Outfall 004 to represent Outfall 002 will not
be granted. This is because the analytical monitored showed values approaching, or in excess of current
stormwater program benchmarks for BOD, COD, Cd, Cu, Pb, TSS and Zn for Outfall 002 and these values
were even higher than Outfall 004.
The site visit on November 11, 2008 was conducted to evaluate the outfall locations. As far as sampling
locations please do not continue sampling in stream. Instead, samples will be taken in the following places:
Outfall 002 (Southeast): same location as previous permit.
Outfall 003 (North): previous samples were taken in stream at the property line. Now, samples will be taken
at the outlet of the North Pond for drainage area 3.
Outfall 004 (West): previous samples were taken in stream at the property. line. Now, samples will be taken
at the outlet near the capped landfill for drainage area 4.
If you have further questions about the sampling locations, please request, again, assistance from the
Mooresville Regional Office.
The draft permit contains the following significant changes from this facility's current permit:
Analytical monitoring changes:
1. Analytical monitoring parameters, BOD, COD, Cd, Cu, Pb, Ni, TSS and Zn, have been maintained in
this permit. Al and Cr have been added to the permit.
2. From the 2008 EPA Multi -Sector General permit, Sector F for Primary Metals recommends adding Al
and Zn based on the SIC code of 3312.
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone] \ Customer Service: 1-877-623-6748
Internet: www.ncwaterquality.org
An Equal Opportunity \ Affirmative Action Employer
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Mr. Anthony S. Read
Gerdau. Ameristeel
Permit No. NCS000304
3. Oil & Grease were added.
4. Phenol was removed from the permit because the monitoring results were significantly under the
current benchmarks.
5. Chromium was also added based on the report that it is present in the Electric Arc Furnace Dust
onsite.
G. pH has been added to the analytical monitoring requirements.
7. All analytical monitoring has been set to quarterly during a representative storm event as defined in Part
II Section B. The permittee must also document the total precipitation for each event. If no discharge
occurs during the sampling period, the permittee must submit a monitoring report indicating "No Flow'
within 30 days of the end of the three-month sampling period.
8. Benchmarks for analytical monitoring have been added to this draft 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. If the
sampling results are above a benchmark value, or outside of the benchmark range, for any parameter at
any outfall then the facility shall follow the Tier 1 guidelines which require a facility inspection within
two weeks and implementation of a mitigation plan within two months. If during the term of this permit,
the sampling results are above the benchmark values, or outside of the benchmark range, for any specific
parameter at a specific discharge outfall two times in a row (consecutive), then the facility shall follow the
Tier 2 guidelines which require a repetition of the steps listed for Tier 1 and also immediately institute
monthly monitoring for all parameters at every outfall where a sampling result exceeded the benchmark
value for two consecutive samples.
9. You are required to conduct all of the analytical and qualitative monitoring during representative storm
events as defined in Part II Section B. Qualitative monitoring is required regardless of representative
outfall status.
10. In the event that this permit expires, you are responsible to continue all monitoring until the renewal
permit is issued. See Footnote 1 of Tables 1, 4, and 5.
11. The flow reporting requirement has been removed per DWQ's revised strategy. (The total rainfall
parameter is still required in this permit, however.)
12. Vehicle maintenance monitoring has been revised to semi-annually in order to coincide with analytical
and qualitative monitoring. This requirement appears in all Individual Stormwater permits, however it
only applies to facilities that conduct vehicle maintenance. If the facility begins vehicle maintenance
during the permitted timeframe then the requirements in Section II.D shall apply.
Other permit changes:
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1. Additional requirements for the Stormwater Pollution Prevention Plan have been specified in Part II
Section A. The plan must also be updated annually to include a list of significant spills and to certify that
the outfalls do not contain non-stormwater discharges.
2. Additional guidance is provided about the Site Plan requirements. The site map must now identify if the
receiving stream is impaired and if it has a TMDL established. It must also describe potential pollutants
in each outfall. The map requirements are stated more explicitly. And, the site plan must contain a list of
significant spills that have occurred in the past three years and also must certify that the outfalls have
been inspected to ensure that they do not contain non-stormwater discharges. Additional information is
provided in Part II Section A.
3. Additional requirements for the Stormwater Management Plan have been specified in Part II Section A.
More details regarding secondary containment are provided.
4. The facility must now implement a semi-annual Facility Inspection Program of the site's Stormwater
management controls as specified in Part II Section A.
Please submit any comments to me no later than thirty (30) days following your receipt of the draft. If no
adverse comments are received from the public or from you, this permit will likely be issued in about two
months.

Mr. Anthony S. Read
' Gerdeu. Ameristeel
Permit No. NCS000304
If you have any questions or comments concerning this draft permit, contact Brian Lowther at [phone]
or [e-mail]
Sincerely,
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Brian Lowther
Environmental Engineer
Stormwater Permitting Unit
cc: Mooresville Regional Office, Mike Parker
Stormwater Permitting Unit
DWQ Central Files
Attachments: Draft Permit