NCS000057_Staff Report_20050607

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Staff Review and Evaluation MRO
NPDES Stormwater Permit
Contact: Jonathan Diggs (919-733-5083, ext. 537)
Facility Name:
Chemical Specialties, Inc.
NPDES Permit Number:
NCS000057
Facility Location:
5910 Pharr Mill Road, Harrisburg, NC Caldwell County
Type of Activity:
Produce specialty chemicals for the wood treating industry
SIC code (if applicable):
2819
Receiving Stream:
Rocky River (impaired for turbidity and fecal coliform)
Stream Classification:
C
Proposed Permit Requirements: See attached draft permit
Compliance Schedule: See Part III, Section A of attached draft permit
Basis for monitoring See attached Monitoring Data Analysis. Removed arsenic, chromium, copper,
requirements: and zinc monitoring. Values for arsenic and chromium were well below the
benchmark values. Copper and zinc are not generally recommended for
stormwater monitoring unless there are known issues, since both are
widespread in nature. However, the permittee reported values that exceeded
the benchmark values for both parameters. Please comment on any concerns
the region might have in removing the zinc and copper monitoring.
In addition, lead monitoring was retained in the permit even though three of the
four samples were below the detection limit. The fourth sample was about 3
times greater than the benchmark values and could therefore be a parameter of
concern. Please comment on the retention of lead monitoring in the
permit.
Basis for other requirements: Monitoring frequency changed to semi-annual in years 1-5. Benchmarks for
analytical monitoring have been added to provide incentive for facilities to
incorporate BMPs to reduce pollutants that exceed benchmark values. These
benchmarks are not cut-off concentrations for monitoring, nor are they permit
limits.
Total Flow monitoring has been removed. The permit still requires Total
Rainfall amount and Rainfall Event Duration be recorded for each sampling
event. This change is also based on the Division's revised strategy for
stormwater monitoring in renewal permits. Please note that the Stormwater
Pollution Prevention Plan (SPPP) site map must include drainage area for each
outfall in acres and the percentage of each drainage area that is impervious (see
Part II, Sec. A).
Added TMDL language per EPA guidance.
Response requested by (date): June 17, 2005 1 3U N 0 7 2005
NPDES Stormwater Permit Application Materials, SfW i1
Documents Reviewed: & Qualitative Monitoring Results summary, NC Integrated Report [305(b) and
303(d) List] (2004 Draft) p
Central Office Contact: Jonathan A. Diggs, ionathaa [e-mail], 919-733-5 OEP NA, r' EAIVIR tr°I
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MAY 2 0 2005
WATER (11UAL" SECTION

Prepared by (Signature)
Date
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Stormwater and General Permits Unit Supervisor
Date
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Concurrerfee by Regional Office
Date
Water Quality Supervisor
Date
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