NCS000134_Draft permit cover letter_20080305

O_FWA Michael F,Easley,Governor
O= �QG Stale of North Carolina
� b William G.Ross,Jr.,Secretary
F Department of Environment and Natural Resources
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pColeen H Sullins, Director
Division of Water Quality
March 5,2008
Mr, Brian Conner
Avoca, Inc.
PO Box 129
Merry Hill,North Carolina 27957
Subject: Draft NPDES Stormwater Permit
Permit No. NCS000134
Avoca, Inc.
Bertie County
Dear Mr. Conner:
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.
The draft permit contains the following significant changes from this facility's current permit:
Analytical monitoring changes:
1, All monitoring parameters have been continued since the previous permit,
2. TSS,nitrogen, and phosphorous have been added to the analytical monitoring requirements.
3. All analytical monitoring has been set to semi-annually 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 six-month sampling
period. Additionally,samples must be taken a minimum of 60 days apart,as specified in Table 2.
4. 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.
5. You are required to collect all of the analytical and qualitative monitoring samples during
representative storm events as defined in Part II Section B. Qualitative monitoring is required
regardless of representative outfall status.
6. You are responsible for all monitoring until the renewal permit is issued. See Footnote 1 of
Tables 1,4,and 5.
7. The flow reporting requirement has been removed per DWQ revised strategy. (The total rainfall
parameter is in this permit,however.)
8. 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 do vehicle maintenance. If the facility begins
vehicle maintenance during the permitted timeframe then the requirements shall appI
North Carolina Division of Water Quality [phone]
1617 Mail Service Center FAX[phone]
Raleigh,North Carolina 27699-1617 On the Internet at http://h2o.enr.state.nc.us/

Mr. Brian Conner
Avoca,Inc.
Permit No. NCS000134
Page 2
Other permit changes:
1. 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 outfaIIs have been inspected to ensure that they do not
contain non-stormwater discharges. Additional information is provided in Part II Section A.
2. Additional requirements for the Stormwater Management Plan have been specified in Part II
Section A. More details regarding secondary containment are provided.
3. Additional requirements for the Stormwater Pollution Prevention Plan have been specified in
Part 11 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.
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.
5. Information regarding the No Exposure Exclusion has been added to this draft permit. If
industrial materials and activities are not exposed to precipitation or runoff as described in 40
CFR§122.26(g), the facility may qualify for a No Exposure Exclusion from NPDES stormwater
discharge permit requirements. Additional information is provided in Part I Section A.
Please note that your facility drains to an area where there are threatened and endangered species. The
Shortnose Sturgeon, (Acipenser brevirostrum)is an endangered species that has been identified near
your facility. Failure to abide by your stormwater permit may constitute violation of the Threatened and
Endangered Species Act.
Based on our understanding of your representations of current site drainage conditions as presented in
your letter dated January 8,2008 and site plan,we are granting the following revision to your monitoring
obligations under NCS000134.
1. You reported that Outfall 001 is representative of Outfall 002. As a result of your report that
Outfall 001 is representative of Outfall 002,Avoca may conduct the required analytical
sampling on Outfall 001 as representative for OutfaII 002,and may discontinue analytical
monitoring of Outfall 002. PIease note that Outfall 002 must still be included in the twice-
yearly qualitative monitoring event.
2. You reported that Outfall 003 is representative of Outfalls 006 and 007. As a result of your
report that Outfall 003 is representative of Outfalls 006 and 007,Avoca may conduct the
required analytical sampling on Outfall 003 as representative for Outfalls 006 and 007,and
may discontinue analytical monitoring of Outfalls 006 and 007. Please note that Outfalls 006
and 007 must still be included in the twice-yearly qualitative monitoring event.
3. Outfall 005 is a non-stormwater discharge covered under a separate NPDES Permit.
Please submit any comments to me no later than thirty (30)days following your receipt of the draft.
Comments should be sent to the address listed at the bottom of this page. If no adverse comments are
received from the public or from you, this permit will likely be issued in about two months.
If you have any questions or comments concerning this draft permit,contact Robert Patterson at(919)
733-5083 x 360 or [e-mail]
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Mr. Brian Conner
Avoca, Inc.
Permit No. NCS000134
Page 3
Sincerely,
Robert D. Patterson, P.E.
Environmental Engineer
Stormwater Permitting Unit
cc: Washington Regional Office,Water Quality Section(w/attachment)
Stormwater Permitting Unit
Attachments
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