NC0003671_PERMIT Modification_19961216

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State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Water Duality
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
December 16,1996
Mr. C.B. Smiley
Amoco Oil Company
P.O. Box 18048
Greensboro, North Carolina 27419
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Subject: Permit Modification
NPDES Permit NCO003671
Amoco Oil Company - Greensboro Ternvnal
Guilford County
Dear Mr. Smiley:
As you may be aware, the public in the Paw Creek area near Charlotte is very concerned with
any activities associated with the oil terminals (including renewal of NPDES permits). The Division
held a public hearing on May 16, 1996, for the renewal of several oil terminal NPDES permits in the
Paw Creek area. Many people attended the hearing and the Division received numerous comments at
the hearing and during the public comment period. As a result of these comments, the Division re-
examined and researched several issues, including chlorophenols. Chlorophenols required a more
extensive research effort than other issues raised during the public comment period. This letter
documents and summarizes.changes to chlorophenols requirements in your permit, and also addresses
some other changes to the permit which reflect concerns raised by the public.
It should be noted that changes to permits pertain to facilities that discharge to water -supply
classified waters only. Permits will not change for facilities discharging to non -water -supply waters.
In response to comments pertaining to the chlorophenol monitoring requirements in the draft
permits, the Division re -investigated the following two questions: (1) Why was there a requirement to
monitor for eight individual chlorophenols in addition to those specified in EPA Method 625; and (2)
What is the proper laboratory procedure to analyze for these eight chlorophenols?
After some additional research and discussion, two determinations were made. First, although
all chlorophenols have the potential to cause taste and odor problems in drinking water supplies and
tainting of fish tissue, the eight chlorophenols mat covered by EPA Method 625 (and singled out for
individual monitoring in the permit) are not considered to be carcinogens. Second, when phenol is
exposed to chlorine, certain chlorophenols form before others. This is significant because a few key
"early -forming" chlorophenols can be used to "screen" the stormwater discharge for the presence of
chlorophenols. Specifically, the five chlorophenols included in EPA Method 625 can be used as
indicators of all chlorophenols because these five compounds would be the first to form when chlorine
reacts with phenol.
Therefore, EPA Method 625 will be used as an initial screen. If no chlorophenols are detected,
no additional monitoring will be required. However, if one or more chlorophenols are detected at
concentrations greater than 50 µg/l, then the oil terminal would be required to monitor for the eight
additional chlorophenols beginning with the next scheduled monitoring event and continue to monitor
P.O. Box 29535, Raleigh, forth Carolina 27626-0535 Telephone [phone] FAX [phone]
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semi-annually until the permit expired. The additional chlorophenol monitoring would include
identifying and quantifying all chlorophenols present in the sample(s).
Although the chlorophenol monitoring requirement change was the most significant, another
concern raised by the public pertained to xylene monitoring. Several members of the public noticed that
xylene monitoring was not required in the draft permits. Xylene is not included in EPA Methods 624/625
and therefore, the Division acknowledges that xylene monitoring should and will be included in the oil
terminals' final NPDES permits.
Please find enclosed the modified section of the permit referenced in the preceding paragraphs.
Replace the original sections in your permit with the newer enclosed sections and discard the original
sections. All other terms and conditions contained in the original permit remain unchanged and in full
effect. These permit modifications are issued pursuant to the requirements of North Carolina General
Statutes 143-215.1 and the Memorandum of Agreement Between North Carolina and the U.S.
Environmental Protection Agency.
If any parts, measurement frequencies or sampling requirements contained in this permit
modification are unacceptable to you, you have the right to an adjudicatory hearing upon written
request within thirty (30) days following receipt of this letter. This request must be in the form of a
written petition, conforming to Chapter 150B of the North Carolina General Statutes, an filed with the
Office of Administrative Hearings, Post Office Drawer 27447, Raleigh, North Carolina 27611-7447.
Unless such demand is made this decision shall be final and binding.
If you have any questions, please contact Charles Weaver at [phone] extension 511.
Sincerely,
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Preston Howard, Jr., P.E.
cc: Central Files
Winston-Salem Regional Office, Water Quality Section
Roosevelt Childress, EPA
ee and'En`giheeri ng-Unit
Facility Assessment Unit
Aquatic Survey and Toxicology Unit