NC0003875_correspondence_19911018

State of North Carolina
Department of Environment, Health, and Natural Resources
Division of Environmental Management
512 North Salisbury Street • Raleigh, North Carolina 27611
James G. Martin, Govemor George T. Everett, Ph.D.
William W. Cobey, Jr., Secretary Director
Mr. Gene F. Renzaglia, Plant Manager
Occidental Chemical Corporation
PO Box 368
Castle Hayne, NC 28429
Dear Mr. Renzaglia:
October 18, 1991 ' 1 ..
OCT 2 3 1991
Subject: NPDES Permit No. NC0003875
Occidental Chemical Corporation
New Hanover County
Reference is made to your letter of October 1, 1991 containing comments on the draft permit No.
NC0003875 for Occidental Chemical Corporation. The Division of Environmental Management
(DEM) has reviewed your letter and is hereby responding to your comments.
(1) The permit sampling requirement for hexavalent chromium has been revised to a daily
composite sample.
(2) The annual pollutant analysis section is a monitoring requirement only. This information
from this analysis is used to identify possible future limited parameters and in a database so
that the DEM Water Quality Planning Branch can determine if standards are needed for any
parameters. As this is a monitoring requirement and not a limit, the requirement does not
need EPA approval, only approval by the DEM director. If additional peaks are present,
tentative identification by computer -aided mass spectrum library searching and minimal
mass spectral interpretation by a mass spectroscopist is all that is required. The verification
of identification obtained by injecting a standard of the tentatively identified compound for a
relative retention time and mass spectrum comparison on the same GC/MS as was used for
sample analysisis not required. Although not required, if verification of tentatively
identified nontargeted compounds is performed, this should be clearly indicated by adding
a brief note to this effect to the pollutant analysis reporting form. Analysis questions may
be directed to Mr. Ray Kelling of the DEM Chemistry Lab at 919/733-3908.
Pollution Prevention Pays
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone]
An Equal Opportunity Affirmative Action Employer

Oh.1,
Your permit is scheduled for issuance on October 18, 1991. The sampling change for hexavalent
chromium has been incorporated into the permit. If you have any questions, you may contact Ms.
Rosanne Barona at 919/733-5083.
Steve W. Tedder, Chief
Water Quality Section
cc: Wilmington Regional Office
Technical Support Branch
Mr. Greg Thorpe
Central Files