NC0073181_Wasteload Allocation_19930708

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NPDES WASTE LOAD ALLOCATION
PERMIT NO.: NCO073181
PERMITTEE NAME: Exxon Chemical Company
FACILITY NAME: Exxon Chemical Company
Facility Status: Existing
Permit Status: Renewal
Major Minor J
Pipe No.: 001
Design Capacity:
Domestic (%p of Flow):
Industrial (% of Flow): 100 %
Comments:
Z wpo" crV r TV SF.c 77i£ 2e6s0..IkC Rc'�o2T - Sf
y,„�� tZx4✓e a `��
RECEIVING STREAM: Cape Fear River
Class: SC
Sub -Basin: 03-06-17
Reference USGS Quad: K27NW (please attach)
County. New Hanover
Regional Office: Wilmington Regional Office
Previous Exp. Date: 9/30/93 Treatment Plant Class:
Classification changes within three miles:
No Chance in Class P L i
Requested by: Sean Goris Date: 4/20/93
Prepared by: Date: 7A7A5
Reviewed by: Date: t�_
Modeler
I Date Rec.
#
6
1 4
ZA 1 '13
Drainage Area (mil ) Avg. Streamflow (cfs):Trrgl,
7Q10 (cfs) Winter 7Q10 (cfs) 30Q2 (cfs)
Toxicity Limits: PJJC % Acut Chronic
Instream Monitoring: �C�` sodtc-
Parameters A1/4"
Upstream
Location
Downstream Location
Recommended I5mitt
Monthly Avg Daily Max. Mon. Freq.
Flow (MCD): monitor
pH (SU): 6.8-8.5 2/month
Oil &Grease (mg/p: 45.0 2/month
TSS (mg/p: 45.0 2/month
Benzene (µg/q: monitor #
Toluene (µgll): monitor #
Ethylbenaae (µg/l): monism #
Xylene (µg/q: monitor #
monitor
OEM) :):) ) monitor #
#Monitoring should correspond with toxicity test sample collection during the Cyst five discrete
discharge "tau after/during a rain event, and annually thereafta.
*If no discharge occurs during the first six months of the year, the permittee should sample far the
above -referenced parameters at the pond during late June. Likewise, if there is no discharge
during the last six months of the year, a sample should be collected at the pond during late
December.
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GKEX88/MP 04/20/93
COMPLIANCE EVALUATION ANALYSIS REPORT PAGE 1
PERMIT--NC0073181 PIPE--001 REPORT PERIOD: 9203-9302 LOC --- E
FACILITY--EXXON CHEMICAL COMPANY DESIGN FLOW-- .0000 CLASS--
LOCATION--WILMINGTON REGION/COUNTY--08 NEW HANOVER
50050 TAA3B TAA3D 00076 00400 00545 00556 01051•
MONTH Q/MGD CERI48AC DAPH48AC TURBIDTY PH RES/SET OIL-GRSE LEAD
LIMIT 9.0 6.0 F .1 F 30.000
92/03
92/04
92/05
92/06
92/07
92/08
92/09
92/10
92/11
92/12
93/01
93/02
AVERAGE
MAXIMUM
MINIMUM
UNIT MGD 9A 9A NTU SU ML/L MG/L MG/L

GKEX88/MP
04/20/93
COMPLIANCE EVALUATION ANALYSIS REPORT PAGE 2
PERMIT--NC0073181 PIPE--001 REPORT PERIOD: 9203-9302 LOC --- E
FACILITY--EXXON CHEMICAL COMPANY DESIGN FLOW-- .0000 CLASS--
LOCATION--WILMINGTON REGION/COUNTY--08 NEW HANOVER
34235 34481 81551
MONTH BENZENE TOLUENE XYLENE
92/09
92/10
92/11
92/12
93/01
93/02
AVERAGE
MAXIMUM
MINIMUM
UNIT UG/L UG/L UG4L

GKEX88/MP 04/20/93
COMPLIANCE EVALUATION ANALYSIS REPORT PAGE 1
PERMIT--NC0073181 PIPE--001 REPORT PERIOD: 9103-9202 LOC --- E
FACILITY--EXXON CHEMICAL COMPANY DESIGN FLOW-- .0000 CLASS--
LOCATION--WILMINGTON REGION/COUNTY--08 NEW HANOVER
50050 TAA3B TAA3D 00076 00400 00545 00556 01051
MONTH Q/MGD CERI48AC DAPH48AC TURBIDTY PH RES/SET OIL-GRSE LEAD
LIMIT 8.5 6.8 F .1 F 30.000
91/03
91/04
91/05
LIMIT 9.0 6.0 F .1 F 30.000
91/06
91/07
LIMIT
NOL
NOL
NOL
NOL
9.0 6.0
F .1 F 30.000 NOL
91/08
.3500
90
90
5.01
8.3-8.3
LESSTHAN 7.900 LESSTHAN
91/09
91/10
91/11
91/12
92/01
92/02
AVERAGE
.3500
90
90
5.01
7.900
MAXIMUM
.3500
90
90
5.01
8.300
7.900
MINIMUM
.3500
90
90
5.01
8.300
7.900
UNIT
MGD
9A
9A
NTU
SU
ML/L MG/L MG/L

GKEX88/MP 04/20/93
COMPLIANCE EVALUATION ANALYSIS REPORT PAGE 1
PERMIT--NC0073181 PIPE--001 REPORT PERIOD: 9003-9102 LOC --- E
FACILITY--EXXON CHEMICAL COMPANY DESIGN FLOW-- .0000 CLASS--
.LOCATION--WILMINGTON REGION/COUNTY--08 NEW HANOVER
50050 TAA3B TAA3D 00076 00400 00545 00556 01051
MONTH Q/MGD CERI48AC DAPH48AC TURBIDTY PH RES/SET OIL-GRSE LEAD
LIMIT 8.5 6.8 F .1 F 30.000
90/03
90/04
90/05
90/06
90/07
90/08
90/09
90/10
90/11
90/12
91/01
91/02
AVERAGE
MAXIMUM
MINIMUM
UNIT MGD 9A 9A NTU SU ML/L MG/L UG/L

ATTACHMENT "A"
APPLICATION FOR PERMIT TO DISCHARGE
FROM HOLDING POND
EXXON CHEMICAL COMPANY
WILMINGTON TERMINAL
WILMINGTON, NORTH CAROLINA
MARCH 1.7,1993

TABLE OF CONTENTS
A. DESCRIPTION OF SITE . . . . . . . . . . . . . . . . . .
B. DESCRIPTION OF WATER . . . . . . . . . . . . . . . . . .
C. CHARACTERISTICS OF WATER . . . . . . . . . . . . . . . .
D. TREATABILITY OF WATER
E . LOCATION OF SUBJECT AREA . . . . . . . . . . . . . . . .
F. PHYSICAL CHARACTERISTICS OF PROPOSED SITE . . . . . . .
G. GENERAL LAYOUT OF SERVICE AREA . . . . . . . . . . . . .
H. RECEIVING WATERS
I. IMPACT OF DISCHARGE ON RECEIVING WATERS
J. EQUIPMENT AND SERVICE FAILURE OR SHUTDOWN . . . . . . .
K. CONSOLIDATION OF FACILITIES . . . . . . . . . . . . . .
FIGURES
Figure 1 Location Map
Figure 2 Topographic Map
APPENDIX
STORMWATER CALCULATIONS . . . . . . . .
STORMWATER ANALYTICAL DATA
LIST OF DRAWINGS
PAC -PP Wilmington Terminal General Plot Plan
1
2
3
3
4
4
4
4
5
5
5
6
7
8
9

ATTACHMENT "All
A.
DESCRIPTION OF SITE
1. Site Name and Location
Exxon Chemical Company
South Wilmington Terminal
3340 River Road
Wilmington, NC 28403
[phone]
Mr. Alfred Smeilus
2. Owner
3. Operator
Exxon Chemical Company
13501 Katy Freeway
Houston, TX 77079-1398
[phone]
Mr. Eric Bruchas
Intermediate Distribution Planner
Paktank Corporation
2000 W. Loop South
Suite 2200
Houston, TX 77027
[phone]
Mr. Quirino Q. Wong
Mgr., Environ. Affairs
The EXXON Wilmington Terminal is located on River Road just
south of the City of Wilmington, in New Hanover County, North
Carolina (see Figure 1). The site is bounded on the west by
the Cape Fear River and on the east by River Road. A plan of
the Wilmington Terminal is included as drawing PAC -PP.
The site topography generally slopes towards the Cape Fear
River (see Figure 2) . The site is drained by a series of
inlets and pipes which directs stormwater runoff into a
holding/storage pond located adjacent to the Cape Fear River.
Effluent from this holding pond is the focus of this discharge
permit application.
Oil/Water Separator No. 1 (see Drawing PAC -PP) is located west
of Tank No. 18 and serves the truck loading rack along with
the containment area containing Tanks 9 through 18 and Tanks
30 through 33. Oil/Water Separator No. 2 is located west of
Tank No. 7 and serves the containment area containing Tanks 1
through 8, No. 19, No. 20 and No. 29.
1

There is a groundwater recovery/treatment system in operation
at this site which also discharges into the storage pond.
This system consists of an interceptor trench, recovery pump
and 4,000 gallon gravity separator.
The gravity separator is equipped with an inverted discharge
pipe which empties directly into the storage pond. No free
product is allowed to enter the pond from this system. Note
also that the pond itself has an inverted outlet and acts as
a separator.
B. DESCRIPTION OF WATER
The sources of influent into the storage pond include
rainwater and effluent from the groundwater treatment system.
As of January 1, 1993 the following products are stored at
this site:
Tank Number
Products Stored
Status
1
Para-Xylene
Active
2
Para-Xylene
Active
3
Out -of -Service -Waiting
' 4
Out -of -Service
5
Out -of -Service
6
Out -of -Service
7
Out -of -Service
8
Out -of -Service
9
Toluene
Active
10
Aromatic-100
Active
11
Hexane RX
Active
12
Varsol-1
Active
13
Lops
Active
14
Aromatic-150
Active
15
Out -of -Service
16
Empty-Varsol 18
Out -of -Service -Waiting
17
Out -of -Service
18
Xylene
Active
19
Out -of -Service
20
Out -of -Service
21
out -of -Service
22
Out -of -Service
23
#6 Fuel Oil
Active
2

,Tank Number Products Stored Status
24
25
26
27
28
29
30
31
32
33
34
2429 Naphtha
2429 Naphtha
Isopar-M
Isopar-M
Mixed Solvent Interface
C. CHARACTERISTICS OF WATER
1. Flow
Out -of -Service
Out -of -Service
Out -of -Service
Out -of -Service
Out -of -Service
Out -of -Service
Active
Active
Active
Active
Active
The discharge from the groundwater treatment system is
continuous and is estimated at 3 gallons per minute.
Estimated peak flow from stormwater is 20.7 cubic feet
per second (see calculations in Appendix 1).
2. Effluent Characteristics
There has been only one stormwater discharge from this
facility since the issuance of this permit on October 17,
1988. The analytical data for this single discharge is
referenced in Appendix 2.
D. TREATABILITY OF WATER
The discharge from the groundwater recovery system is directed
through an oil/water separator and, therefore no. free product
is allowed to enter the pond. Free product accumulations in
the oil/water separators are periodically transferred to the
interface tank (Tank 34).
The existing method of treatment of water prior to discharge
to the Cape Fear River is by. means of routing stormwater
through oil/water separator then collecting the water in a
holding pond. The pond is approximately 2.5 acres is size and
3

is equipped with an inverted outlet discharging into the Cape
Fear River. The stormwater delivered to this pond is treated
through a combination of evaporation and volatilization of
organic constituents, and biodegradation by naturally
occurring organisms.
The pond does not discharge on a continuous basis. Discharge
into the Cape Fear River is intermittent based on the amount
of frequency of rainfall.
E. LOCATION OF SUBJECT AREA
The site is located at 3340 River Road near Wilmington, North
Carolina (see Figures 1 and 2).
F. PHYSICAL CHARACTERISTICS OF PROPOSED SITE
Not Applicable
G. GENERAL -LAYOUT OF SERVICE AREA
Not Applicable
H. RECEIVING WATERS
1. Name and location of receiving waters - Cape Fear River
(see Figure 2).
2. Design stream flow: Cape Fear River, flow unknown.
3. Chemical and biological characteristics of receiving
waters - unknown.
4. Zone of influence - Not Applicable
9

I. IMPACT OF DISCHARGE ON RECEIVING WATERS
Due to the degree of treatment in the storage lagoon and
intermittent flows, no significant impact on receiving waters
is expected.
J. EQUIPMENT AND SERVICE FAILURE OR SHUTDOWN
The groundwater recovery/treatment system can be shut down
completely for any necessary maintenance, making bypassing of
components unnecessary. During power failures, no discharge
from this system will occur since the sump pump will be out of
service.
K. CONSOLIDATION OF FACILITIES
Not Applicable
5

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FIGURE #1
LOCATION MAP
Richard Catlin do Associates, Inca
um
caysucrnac ENC.WUU mcd,
AND +HY�CWA(X0 Sn

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TmY x i • :/, 0,
Farm
35
.1. ■22. I/ j
STORAGE POND
T"k
w.5 6.8
EXXON COMPANY
WILMINGTON TERMINAL
APPROXIMATE SITE
BOUNDARY
TOPOGRAPHIC MAP
FIGURE #2
TWA Fam
x 2l.3

APPENDIX 1
STORKWATER CALCULATIONS

DETERMINE PEAK STORMWATER DISCHARGE
Q s C I A
ASSUME C 0.2
A - 23 ACRES
T.O.C. - 20 MIN
I 4.5 "/HR RETURN PERIOD = 10 YEARS
Q - 0.2 X 23 X 4.5 - 20.7 CFS
t
4
i

APPENDIX 2
STCRKWATER ANALYTICAL DATA

• ,
C onsu�'n �n� •• nu ��l'G�m�sfs
E$TABLISHE019W
JI%sin ONiae
1711 Castle Wmt 810.782 MW 010.7024M
P.O. Box 09 FAX 019-n"788
Wllmlr'IptDA, N.C. QP REPORT DATE: 8-09-91
SOUTH WILMINGTON TERMINAL DATE RECEIVED: 8-06-91
C/O PAKTANK CORP. DATE COLLECTED: 8-06-91
P.O. Boa 1350 COLLECTED BY: LAW & COMPANY
WILMINCTON, N.C. 28402 LAS I.D.f EW 7989
ATTN : AL SMS ILVS
SAWM DESCRIPTION: RETEST ION POpD
TESTS/SAMPLES
UNITS
RESULTS
_
pK
8.3
OIL & GREASE
PPM
7.9
SBTTLBABLE SOLIDS
ML/L
<0.1
BBmwg
PPE
<0.2
TOLUENE
PPB
c0.2
AYLENE
PPB
<0.2
TUBIDITY
NTU
5.01
LEAD
PPM
<0.01
KERASSIM
PPB
<50
VAUOL
PPB
4.3
ACUTE TOXICITY - DAPHVID 48 RKS.
Report to follow.
--&k A 0 -1 - aL,*�
Laborat y Director

Effluent Toxicity 11cj)ort norm• Chronic I'uss/Full 1t1W Acut.c LCUO tmle
• l � Law i Company NMESINC* - lope N t.0juc cty
Laboratory PIerforinin.I.-Raiaarch i Analytical Cot111ttclit9
,..._
x
Signature of Operator In Responsible Chnrge
1 . I N A L TO: ®1v.lof Envl onmenoll Mono emetis
M� L BRIGg
IN.C. Dept, of El-HZ
P. O. Boot 27687
forth Ca allna Cedodanhnla Chronic Passlr g Egor2duction Blonsany Odelgh, Norlh Cambia 27611
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WOODED AREA
I MPE, INC. I
PAUAW-EXXON FACILITY
WU"GTON. NC TEPMONAL
ALAAL PLOT PLAN

A. (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS Final
NPDES No. NC0073181
During the period beginning on the effective date of the permitand lasting until
expiration the Permittee is authorized to discharge from outfall(s) serial number(s) 001.
discharges shall be limited and monitored by the Permittee as specified below:
Effluent Characteristics
Lbs da
Daily bva. Daily Max.
Flow
Flow
Oil and Grease
Settleable Solids
Phenols
Turbidity
Acute Toxicity
Benzene
Toluene
Xylene
Kerosene
Varsol
Lead
Discharge Limitations
Other Units (Specify)
Daily Avg. Daily Max.
30.0 mg/1
Q.1 ml/i
50.0 mg/1
0. 2? ml/1
Monitoring Requirements
Measurement
Sample
Sample
Frequency
1Ye
Location
Continuous
Recording
E
or Weekly
Flow Totalizer E
2/Month
Grab
E
2/Month
Grab
E
2/Month
Grab
2/Month
Grab
E
Grab
F,
** `
Grab
E
Grab
E
`"� �•
Grab
E
Grab
E
't '`•
Grab
I;
Grab
E
`Sample locations: E-Effluent
Samples taken in compliance with the monitoring requirements specified above shall be taken at the following
locations(s): the nearest accessible point after final. treatment but prior to actual
discharge to or mixing with the receiving waters.
Monitoring will be conducted during normal works hours.
This permit imposes no limitations on the discharge of stormwater runoff uncontaminated by an industrial or
commercial activity and not discharged through any oil/water separator or other treatment equipment or facility.
:... '
`'The discharge shall not cause the turbidity of the receiving water to exceed 50 NTU.
If the turbidity exceeds these levels due to natural background conditions, the discharge level cannot cause any
increase in the turbidity in the receiving water.
*Acute Toxicity (Daphnid 48 hour) Monitoring, Episodic, See Part II1, Condition No. G.
****Monitoring shall be conducted during the first five discrete discharge events after the effective date of this
permit.
Such
Continued on next page. . . .

}
Permit No. NC00073181
I
The pH shall not be less than 6.8 standard units nor greater than 8.5 standard units and shall be monitored 2/Month at
the effluent by grab sample.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
_M, 3
YYr.w�

Facility Name:
NPDES No.:
Type of Waste:
Facility Status:
Permit Status:
Receiving Stream:
Stream Classification:
Subbasin:
County:
Regional Office:
Requestor:
Date of Request:
Topo Quad:
FACT SHEET FOR WASTELOAD ALLOCATION
Exxon Chemical Company
NC0073181
Industrial - 100%
Existing
Renewal
Cape Fear River
SC
030617
New Hanover
Wilmington
Goris
4/20/93
K27NW
Wasteload Allocation Summary
(approach taken, correspondence with region, EPA, etc.)
Request #
7-135
az434
Stream Characteristic: TIDAL
USGS #
Date:
_
Drainage Area (mil)
r
Summer 7Q10 (cfs):
`0
Winter 7Q10 (cfs):
v
c
Average Flow (cfs):
X
30Q2 (cfs):
'IWC
c
tT
-
The previous permit had monitoring for kerosene and varsol. This is not usually given to these
discharges, so this requirement will be deleted. Phenols monitoring has typically been required
only at discharges which go to streams above a water supply. This requirement will also be
deleted. Some monitoring frequency changes were also recommended.
Special Schedule Requirements and additional comments from Reviewers:
S©C ,&I` BF /fvr/Cw7b1?y , 'Z rla/- iTdk -r,
-be `?A0,7n/u G--D,
Recommended by: (�I1Z��/ Date:
Reviewed by //�� n W Q
InstreamAssessment: 2(je/ Leg^- [1Otlt"y\-- Date:
Regional Superviso la ' LY, 1, Date: — (�, - �t�
ffPermits & Engineering: e Date: Z G( 3
Nam- 5
RETURN TO TECHNICAL SERVICES BY:

TOWS/CONVENTIONAL PARAMETERS
Type of Toxicity Test: Acute 48-hour test using ceriodaphnia
Existing Limit:
monitoring
Recommended
TestlLimit:
Acute 24-hour monitoring using fathead minnows
Monitoring Schedule:
First five discrete discharges after/during a rain event
Existing Limits
Daily Avg Daily Max.
Flow (MGD):
monitor
pH (SU):
6.8-8.5
Oil & Grease (mg/1):
30.0 60.0
Settleable Solids (ml/l):
0.1 0.2
Benzene (µg/1):
monitor
Toluene (µg/l):
monitor
Kerosene (µg/l):
monitor
Xylene (µg/l):
monitor
Varsol (µg/l):
monitor
Lead (µg/l):
monitor
Phenols (µg/1):
monitor
Recommended Limits
Monthly Avg Daily Max. Mon. Freq.
Flow (MGD): monitor
pH (SU): 6.8-8.5 2/month
Oil & Grease (mg/1): 45.0 2/month
TSS (mg/1): 45.0 2/month
Benzene (µg/1): monitor #
Toluene (µg/l): monitor #
Ethylbenzene (µg/1): monitor #
Xylene (µg/l): monitor #
MTBE (µg/l): monitor #
Lead (µg/1): monitor #
#Monitoring should correspond with toxicity test sample collection during the first five discrete
discharge events after/during a rain event, and annually thereafter.
*If no discharge occurs during the first six months of the year, the permittee should sample for the
above -referenced parameters at the pond during late June. Likewise, if there is no discharge
during the last six months of the year, a sample should be collected at the pond during late
December.
(See page three for special monitoring requirements.)
Limits Changes Due To:
Change in 7Q10 data
Change in stream classification
Relocation of discharge
Change in wasteflow
New pretreatment information
Failing toxicity test
Other (onsite toxicity study, interaction, etc.)
Instream data
New regulations/standards/procedures
x O&G, Varsol, Kerosene,
Phenols, TSS

.21-3
MISCELLANEOUS INFORMATION & SPECIAL CONDITIONS
Adtuacy of Existing Treatment
Has the facility demonstrated the ability to meet the proposed new limits with existing treatment
facilities? Yes No
If no, which parameters cannot be met?
Would a "phasing in" of the new limits be appropriate? Yes No
If yes, please provide a schedule (and basis for that schedule) with the regional
office recommendations:
If no, why not?
MMIAMNUM161
BTEX parameters and MTBE should be monitored using an EPA -approved method to a
detection level of 1 ppb. Permit must contain flow monitoring requirement such that all volumes
of wastewater leaving the facility are monitored. Recommend continuous flow monitoring.
Recommend quarterly monitoring for those chemical parameters to be limited or monitored. This
monitoring should coincide with all whole -effluent toxicity monitoring.
A reopener clause should be placed in the permit to allow for additional limits on these or other
toxicants should the whole -effluent toxicity testing results indicate toxic effects.
Explain exact pathway of discharge ( i.e. storm sewer to tributary, etc.)
Additional Information attached? (Y or N) If yes, explain with attachments.

a
Permit* .� � Pipe # �� �
Facility Name kxye-� (, 'j.
ACUTE TOXICITY MONITORING (EPISODIC)
The permittee shall conduct FIVE acute toxicity tests using protocols defined as definitive in
E.P.A. Document 600/4-85/013 entitled "The Acute Toxicity of Effluents to Freshwater and
Marine Organisms." The monitoring shall be performed as a Fathead Minnow (PbWhales
promelas) 24 hour static test, using effluent collected as a single grab sample. Effluent samples
for self -monitoring purposes must be obtained below all waste treatment. Sampling and
subsequent testing will occur during the fast five discrete discharge events after the effective date
of this permit. After monitoring of the first five toxicity tests, the pernittee will conduct one test
annually, with the annual period beginning in January of the next calendar year. The annual test
requirement must be performed and reported by June 30. If no discharge occurs by June 30,
notification will be made to the Division by this date. Toxicity testing will be performed on the
next discharge event for the annual test requirement.
The parameter code for this test is TAE6C. All toxicity testing results required as part of this
permit condition will be entered on the Effluent Discharge Form (MR-1) for the month in which it
was performed, using the appropriate parameter code. Additionally, DEM Form AT-1 (original) is
to be sent to the following address:
Attention: Environmental Sciences Branch
North Carolina Division of
Environmental Management
4401 Reedy Creek Rd.
Raleigh, N.C. 27607
Test data shall be complete and accurate and include all supporting chemical/physical measurements
performed in association with the toxicity tests, as well as all doselresponse data. Total residual
chlorine of the effluent toxicity sample must be measured and reported if chlorine is employed for
disinfection of the waste stream.
Should any test data from either these monitoring requirements or tests performed by the North
Carolina Division of Environmental Management indicate potential impacts to the receiving stream,
this permit may be re -opened and modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum
control organism survival and appropriate environmental controls, shall constitute an invalid test.
Failure to submit suitable test results will constitute noncompliance with monitoring requirements.
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SOC PRIORITY PROJECT: No
To: Permits and Engineering Unit "
Water Quality Section
Attention: Sean Goris
(Review Engineer)
Date: May 51 1993
NPDES STAFF REPORT AND RECOMMENDATI iN
County: New Hanover
Permit No. NCO073181
PART I - GENERAL INFORMATION
E
WY`07 1993
ECH 'CAL SOPPORT INCH
1. Facility and Address: EXXON Chemical Company
South Wilmington Terminal
Post Office Box 1350
3340 River Road
Wilmington, N.C. 28403
Corporate Environmental Affairs Office: Paktank Corporation
2000 W. Loop South
Suite 2200
Houston, Texas 77027
ATTN: Quirino Q. Wong
2. Date of Investigation: April 29, 1993
3. Report Prepared by: Jim Bushardt
4.- Person Contacted and Telephone Number: Alfred Smeilus
[phone]
5. Directions to Site: The facility is located in Wilmington at
3340 River Road.
6. Discharge Point:
.Latitude: 34*1014311 Longitude: 7805711611
U.S.G.S. Quad No: K27NW USGS Quad Name: Wilmington, N.C.
7. Site size and expansion area consistent with application ?
Yes

8. Topography: The site slopes downward approximately 30 feet
toward the river and the oil/water separators are considered
to be located out of the 100 year flood plain. '
9. Location of nearest dwelling: The closest dwelling is located
approximately 1/2 mile southeast of the facility.
10. Receiving stream or affected surface waters: Cape Fear River
a. Classification: Class "SC" waters
b. River Basin and Subbasin No.: 03 06 17
C. Describe receiving stream features and pertinent
downstream uses: Commercial shipping, boating,
fishing, and hunting.
PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
1. a. Volume of Wastewater to be permitted: Variable,
depending on precipitation events.
b. What is the current permitted capacity of the wastewater
treatment facility? No flow limit specified.
C. Actual treatment capacity of the current facility
(current design capacity)? Unknown
d. Dates and construction activities allowed by previous
Authorizations to Construct issued in the previous two
years: No A to C's have been requested within the past
two years.
e. Please provide a description of existing or substantially
constructed wastewater treatment facilities: Gravity
oil/water separators to 2.5 acre unlined lagoon to
discharge weir and effluent conduit.
f. Please provide a description of proposed wastewater
treatment facilities: Not applicable
g. Possible toxic impacts to surface waters: Dissolved
petroleum constituents.
h. Pretreatment Program: Not a POTW
2. Residuals handling and utilization/disposal scheme:
There is no sludge produced on the site. The floatable product
is stored within an interface tank and is periodically sold.
The present waste disposal operator is the Primary Corporation
of Richmond, Va.
3. Treatment plant classification: Class 1 facility

4. SIC Code: 5171
• Wastewater Code: Primary: 39 Secondary: 66
Main Treatment Unit Code: 53500
PART III - OTHER PERTINENT INFORMATION
1. Is this facility being constructed with Construction Grant
Funds or are any public monies involved? Not applicable
2. Special monitoring or limitations requests: See comments
within Part IV.
3. Important SOC, JOC or Compliance Schedule dates: None
4. Alternative Analysis Evaluation: Has the facility evaluated
all of the non -discharge options available? Please provide
regional perspective for each option evaluated.
Spray Irrigation: Sandy soils are prevalent in the area.
Sufficient area is probably available. The site has several
petroleum contaminated groundwater plumes which could cause
problems in the monitoring activity.
Connection to Regional Sewer System: The POTW will not take
treated waste into the collection system unless the discharge
is within an environmentally sensitive area. This portion of
the river exhibits a large flow volume, contains many
discharge points, is classified as "SC" waters and is not
considered to be environmentally sensitive.
Subsurface: This option may not be feasible, due to
interference with contaminated groundwater plumes which exist.
5. Other Special Items: None
PART IV - EVALUATION AND RECOMMENDATIONS
This report is being prepared due to a permit renewal request.
The EXXON South Wilmington Terminal receives petroleum products
from tanker ships. The products are stored in metal tanks of
various design and dispensed to tanker trucks. The products in the
current inventory are mainly petrochemical products and include
toluene, aromatic-100, hexane RX, varsol-1, D-80 (an aliphatic
hydrocarbon), D-40 (an aliphatic hydrocarbon), aromatic-150,
xylene, 2429 naphtha, and isopar-M. The waste streams at this site
include stormwater flows from containment areas (estimated at 20.7
cfs peak flow).. groundwater remediation at approximately 3 gpm flow
rate, and tank condensate drainage. Due to the current inventory of
products and type of tanks used, tank condensate drainage is not
currently performed. Terminal supply lines are flushed with water
prior to product changes and wastewater is removed to the interface
tank for future disposal,

The 2.5 acre pond does not discharge through the effluent
'piping on a routine basis. There is very little effluent
water quality history available for this facility (low BTEX
concentrations and passed toxicity test in 1991) due to this
reason. Naturally, the Permittee thinks of this situation as
desirable. The pond is located along the river and is
separated by an earthened dike. The writer assumes that the
pond water level is effected by the river and that subsurface
flow allows percolation of water through the dike and into
the river during low tide events or during periods of high
pond levels. The pond has three groundwater monitoring wells
located on the dike along the pond perimeter. Research into
available groundwater files to determine the quality of
groundwater in the monitoring wells showed that groundwater
standards were not being violated. This data was taken from
a 1991 report. The pond displayed patchy light sheens on the
surface. The terminal manager assumes that the sheens are
caused by older petroleum product residuals surfacing from
the pond bottom because products in the current inventory do
not produce a colored sheen. The pond should allow
Volatilization of separated residuals.
The groundwater remediation system (recovery trench,
pump, and gravity separator) would not be considered adequate
under normal conditions. However, since the effluent is to
the pond, which seldom discharges, and perimeter dike
monitoring wells show groundwater quality to be acceptable,
the writer recommends that no system upgrades be required at
this time due to the lack of information concerning treatment
efficiency of existing systems. The river displays a high
flow volume and velocity adjacent to the pond. Ambient water
quality samples of the river at this point would probably
indicated normal water quality due to the dilution and mixing
action.
The current monitoring requirements appear to be adequate
for this type of facility. Effluent limits for lead, toluene
and benzene should be specified which are consistent with the
NCG510000 General Permit. Kerosine is not currently stored
at the site and should be removed from the monitoring list.
The permit should contain a clause which requires pond water
sampling at the effluent conduit location on biannual
frequencies (late June and late December) if no pond
discharge has occurred within the 6 month time interval,
lk7owever, if pond water testing is required, no effluent
limits should be specified. The permit specifies continuous
flow monitoring but the facility has an instantaneous flow
measurement device. The writer suggested the installation of
a pond level indicator in 1991 for measuring pond level
changes over a measured time interval for determining
discharge volume and rate of the intermittent discharge
activities. This system appears to be adequate. In addition,
operations personnel maintain pond level records. Section C.6
of the current permit should be modified to specify
"domestic" sewage sludge as pertaining to 40 CFR Part 503
requirements. There is no domestic sewage sludge produced on
this site.

The supplement sheet defines the treatment system as having
,eight oil/water separators. Some of these separators were small
units which served only one tank. Due to physical changes on some
tanks, individual oil/water separators are no longer needed (no
tank condensate drainage) and they have been removed. There are two
large (20,000 gal and 4,000 gal) separators at the site.
It is recommended that NPDES Permit No. NC0073181 be prepared
and placed at public notice. If no significant adverse public
comment is received, it is recommended that NPDES permit NC0073181
be reissued to the EXXON Chemical Company -South Wilmington Terminal
in accordance with the basinwide permitting strategy.
Signature of report preparer
Water Quality Regional Supervisor
ENCLOSURE
JB:EXXON.MAY
cc: Wilmington Office Files
Central Files
Technical Support Branch
Date
Dat

%F7
MAY-,Ap-
RTN CHZMIChL COMPANY
,UTH WILMINGTON TFRMINn 3e
--DES PERMIT NO. NCO073181
jAD SHEET: WILMINGTON, N.C.�
IN
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REM
(1)
(2)
(3)
RATING SCALE IFOR CLASSIFICATION OF FACILITIES
s
• Name of Plant: — • ,,�,
Owner or Contact Per /t.-f s
Mailing Address: ,
2 9 1/0��
County;Telephone: 7� rr ��
NPDES Permit No. Co 7 Nondisc. Per. No. _
IssueDate: Expiration Date: C=
Existing Facilit S New Facility
• Rated By: Date:
Reviewed (Train. & Cert.) Reg. Office
Reviewed (Train. & Cert.) Central Office
ORC
Grade
Plant Class: (circle one) I II 111 IV Total Points C7
POINTS
Industrial Pretreatment Units and/or
Industrial Pretreatment Program
(see definition No. 33)
4
DESIGN FLOW OF PLANT IN GPD
(not applicable to non -contaminated cooling waters. sludge
handling facilities for water purification plants. totally
dosed cycle systems (del. No. 11). and facilities
consisting only of Item (4) (d) or Items (4) (d) and (11) (d))
0 -- 20.000..........................
20.001 -- so.000
1
..........................
50.001 » 100.000....................... ..
2
3
100.001 » 250.000..........................
4
250.001 -- 50o.00o ..........................
5
500.001--1.000.000..........................
8
1.000.001 » 2.000.000 ......................
10
2.000.001 (and up) - rate 1 point additional for each
200.000 gpd capacity up to a
maximum of 30
Design Flow (gpd) :
PRELIMINARY UNITS (see definition no. 32)
(a) Bar Screens ................................
or
(b) Mechanical Screens. Static Screens or
Comminuting Devices ....................... .
(c) Grit Removal ...............................
or
(d) Mechanical or Aerated Grit Removal tar......... .
(e) Flow Measuring Device .......................
or
(f) Instrumented Flow Measurement ..............
(9) Preaeration ................................
(h) Influent Flow -Equalization ................... 2
(Q Grease or Oct Separators • Gravity ..........;
Mechanical ...... :...
Dissolved Air Flotation. 8
() ftechbrination .............................. 5
(4) PRIMARY TREATMENT UNITS
(a) Septic Tank (see defudtion no. 43) .............. 2
(b) Imhoff Tank .................................. 5
(c) Primary Clarifiers. ............................ 5
(d) Settling Ponds or Settling Tanks for Inorganic
Nontoxic Materials (sludge handling facilities
for water purification plants. sand. gravel.
stone. and other mining operations except
recreational activities such as gem or gold
...................................... 2
(5) SECONDARY TREATMENT UNITS
(a) Carbonaceous Stage
(Aeration High Purity Oxygen System
Diffused Air System ...........
Mechanical Air System (fixed,
floating or rotor) ..... , , ,
Separate Sludge Reaeration .....
(ii) Trickling Filter
High Rate ...................
Standard Rate ...............
Packed Tower ....
(iii) Biological Aerated Filter or Aerated
Biological Filter ......................
(iv) Aerated Lagoons .....................
(v) Rotating Biological Contactors ..........
(vi) Sand Filters -
Intermittent biological .... .
recirculating biological .... .
(vn Stabilization lagoons ...................
W10Clarilier ..............................
(ix) Single stage system for combined
carbonaceous removal of SOD and
nitrogenous removal by nitrification
(see del. No. 12) (Points for this Item
have to be In addition to items (5) (a)
n through (5) (a) (vtu .................
(x) Nutrient additions to enhance SOD
removal ...............................
(xi) Biological Culture ('Super Bugs') addition
b enhance organic compound removal .... .
(b) Nitrogenous Stage
(1) Aeration - High Purity Oxygen System .... .
Diffused Air System .... ..... .
Mechanical Air System (fixed,
floating. or rotor) ...... ......
Separate Sludge Reaeration .... .
(ii) Trickling Filter -
High Rate ..............
Standard Rate ............
Packed Tower............
(Ili) Biological Aerated Filter or Aerated
Biological Filter .........................
(W) Rotating Biological Contactors ............
(v) Sand Filler.
intermittent biological ........
recirculating biological ........
(vi) Clarifier ................................
20
10
8
3
7
5
s
10
10
10
2
3
S
5
8
5
5
20
10
8
3
7
5
5
10
10
2
3
5

(6) TERTIARY OR ADVANCED TREATMENT UNIT
(a) Activated Carbons Beds -
• without Arbon regeneration
(10) CHEMICAL ADDITION SYSTEM (S) (See definition No. 9)
.................. 5
with carbon regeneration .................... 15
(not applicable to chemical additions rated as item
(3) G). (5) (a) (Q. (6) (a). (6) (b). (7) (b).
4b) Powdered or Granular Activated Carbon Food .
(7) (e}.
(9) (a). (9) (b). or (9) (c) 5 points
without carbon regeneration
each: List:
................. 5
vrhh eeration
carbon � .................... 15
...... 5
(c) Air� Stripping ........................ 5
(d) Derutnfication Process (separatep
...... 5
• ..... 5
process) ..... 10
(e) Elec trodiaWs ............................. 5
• • .... 5
.
(� Foam Separation ............................. 5
(9) lon 6tthange
(11) MISCELLANEOUS UN ITS
................................ 5
(h) Land Application of Treated Effluent
(a) Holding Ponds. Holding Tanks or Settling Ponds
for Organic or Toxic Materials Including
(see definition no. 22b) (not applicable for
wastes
from mining operations containing nitrogen
sand, gravel, stone and other similar mining
and/or
phosphorous compounds In amounts significantly
operations)
(i} on agridrlturagy managed sites (See clef.
greater than Is common for domestic wastewater ���
(b) Effluent Flow Equalization (not applicable to
No. a) ................................... 10
(ii) by high rate infiltration on non -agriculturally
storage
basins which are inherent in land application systems) . 2
(c) Stage Discharge (not applicable to storage basins
managed sites (includes rotary distributors
Inherent inland application syslems
and similar fixed nozzle systems) ........... q
.............»„», ,,,,,,,.•,,,,,•�. 5
(d)Pumps
(iiQ by subsurface disposal (includes low pressure
(a) Stand -By Power Supply..,,...,»••,,,,,,_,
pipe systems and gravity systems except at'
3
(f j Thermal Pollution Control Device:,,.,,,•••,,,,,»,,,»„»,,,,•_.�.»»..
plants consisting of septic tank and nitrifica-
3
lion lines only) .................. .......... q
(ij Microsereens.................................. 5
Phosphorus Remoral by Biological Processes
TOTAL POINTS -
(See def. No. 26) ............................ 20
(k) Polishing Ponds - without aeration
CLASSIFICATION
....... 2
with aeration .......... 5
Class ! 5 - 25 Points
Post Aeration •
n) cascade .............. 0
1• 26. 50 Points
Class 111
diffused or mechanical ... 5
Class tV 51. 65 Points
(m) Reverse Osmosis ............................... 5
(a) Sand or Mixed -Media Filters - low rate
66- Up Points
........... 2
high rate
Facilities having a rating of one through four points. Inclusive.
.......... 5
(o) Treatment processes for removal of metal or
do not require a certified operator. Classificationof all other
facilities requires a comparable
cyanide .................................... 15
(p) Treatment processes for removal of toxic
grade opeirator� in responsible
charge.
materials other than metal or cyanide .... • .... 15
Facilities having an activated sludge process will be assigned
a minimum classification of Class I.
LUDGE TREATMENT
(a) Sludge Digestion Tank - Heated ............... 10
Facilities having treatment processes for the removal of metal'
.. • , « ...... • .. 5
or cyanide will be assigned a minimum classification of Class it.
g ( Unheated...... l ....... 3
(b) Sludge Siabfi,tation (chemical or thermal) .... , , . 5
Facilities having treatment processes for the biological removal
P
(e) Sludge Drymmg Beds - Gravity ................. 2
of phosphorus will be assigned a minimum classification of Class
Vacuum Assisted ....... 5
Ill.
(d) Sludge Efuldation ......
... ............
5
........ .. ...
(a) Sludge Conditioner (chem�iccal or thermal) ........ 5
In -plant processes and related control equipment which are an
(f) Sludge Thickener (gravity) .. , • . , , , • , .. • .... , .... 5
(9) Dissolved Air Flotation Unit
Integral part of industrial production shall not be considered waste
treatment. Likewise, discharges of wastewater from residences
(not applicable to a unit rates as (3) 11 ......... 6
having a design now oI 1.000 gpd or less, shall not be subject to
() Sludge Gas UtiGtation (including
h dD (' g gas storage) .... 2
rating.
M Sludge Holding Tank - Aerated ................ 5
Wri-aerated ............ 2
Sludge incinerator • (not Including activated
carbon regeneration) ..... 10
(k) Vacuum tiler. Centrifuge or Filler Press or other
10
SLUDGE DISPOSAL (mdud ng indinetated ash)
(a) Lagoon:......................................... 2
(b) Land Application (surface and subsurface)
(see definition 22a)
-where the facility holds the land app. permit ... 10
-by contracting to a land application operator who
holds the land application permit ................ 2
•land application of sludge by a contractor who does
not hold the permit far the wastewater treatment
facility where the sludge is generated ......... 10
(c) Landfilled (burial) ............................. 5
DISINFECTION
(a) Chlorination ............................. 5
(b) Dechbrinalion
........................ 5
(c) Ozone .............................. 5
(a) Radiation
.......................... 5