NC0005185_WASTELOAD ALLOCATION_19960726

MPDES DOCYNEMT SCANN1NC COVER SHEET
NPDES Permit: NC0005185
Document Type: Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Speculative Limits
Staff Report
Instream Assessment (67B)
Environmental Assessment (EA)
Permit
History
Document Date: July 26, 1996
Tlhila document 1M printed on reume paper-ignore arty
content on the x-eYerae aide

NCGO005185- Summary
July 26, 1996
Amoco Oil Company has submitted a renewal application of their NPDES permit for permission to
discharge treated groundwater and stormwater from their facility .
There are three treatment systerns at the facility. The treatment system at the loading dock consists of a
containment area and an oil/water separator. Stormwater from the loading dock area goes through the
oil/water separator before discharging through outfall 006. There are two groundwater remediation
treatment systems: an onsite system and an offsite system. The onsite system consists of seven recovery
wells, 50 gpm oil/water separator, 100 gpm transfer pump, dual five tray low profile air stripper (50 gpm)
with 500 gallon surge tank, 100 gpm influenUeff7uent transfer pump, 600 cfrn blower, and bag filter
system. The offsite system consists of five recovery �;Jells (15 gpm total), four recovery we]Is for-GNC
system (9 gpm total), 35 gpm oiUwater separator, 300 gallon transfer tank, 40 gpm transfer pump, a five
tray low profile cascade air stripper (50 gpm) with 500 gallon surge tank, 100 gpm influent effluent
transfer pump, and bag filter system. Both on- and offsite systems cornbine to one. 1800 pound carbon
unit rated at 180 gpm (259,200 GPD = 0.259 MGD).
Groundwater Treatment Discharge (utfall 005)
The effluent will discharge through oud all 005 to an unnamed tributary to the Lower Creek (WS-1V
waters) in the Catawba River basin .
Examination of the existing permit (and the parameters that are monitored) indicate that the groundwater
contamination resulted from gasoline.
Examination of the existing DMR data for the period 1/94-2/96 indicate the that facility is generally meeting
its permit requirements, but is discharging on an infrequent basis. A summary of the data follows:
Date . Flow a pH BOD Benzene Toluene Eth,, 1� Phenol MTBE
(MGD) rn- U 1 Ua ua ua M
9408 0.014633 6.4 ND ND ND ND ND 92
9409 0.008249 6.9 ND ND ND ND ND 29
9410 0.005376 6.8 4.3 ND ND ND ND 0.016
9411 0.002860 6.9 23.3 ND ND ND ND 0.42
9504 0.026569(b) 6.9 0.876 ND ND ND ND 2. 1
(a) Monthly average
(b) Instantaneous flow measurement
ND=not detected
Mr. Steve Jolley(Amoco Oil Company) stated that the ND means not detected. In the future, Amoco will
use a less than sign (<) followed by the detection limit. ND could be misinterpreted to mean "no data" and
BDL wits also used by Amoco to mean below detection level, thus causing confusion. In addition,
detection levels can vary depending upon the analysis and the laboratory conducting the analysis.
Therefore, a less than sign followed by the detection limit is more informative.
Although there have been no detections of benzene, toluene, or ethyl benzene over the past two years, the
benzene and toluene limits and ethyl benzene monitoring will remain in the permit because of the changes
in the groundwater treatment system. Benzene and toluene are limited because there are state standards
(see T15A 02B .0211 or.0212) for both of these parameters. There is no state standard for ethyl benzene.
There are federal human health criteria for ethyl benzene, but no federal freshwater aquatic life criteria.
The discharge is into Class C waters so the human health criteria is not applicable in this case. There is a
state criterion of 325 ug/l for ethyl benzene. Ethyl benzene is not limited (while benzene and toluene are
limited) because of the following: (1) Benzene and toluene have state standards, ethyl benzene has only a
state criteria (not yet approved on federal level) and (2) The benzene and toluene standards are lower than
the criterion for ethyl benzene.

NCG0005185 Sumn1ary
July 26, 1996
There have also been no detections of phenol over the past two years, but a monitoring only requirement
will remain in the permit because of the changes in the groundwater system. The phenol limit of 1.0 ug/l
has been eliminated because it was intended for chlorophenols (not phenol). Taste and odor and/or
tainting of f-ish tissue can occur in waters where chlorophenols are measured at concentrations greater than
or equal to 1.0 ug/l. Because taste and odor in drinking water- is a potential problem in water supply
classified waters, not non-water supply waters, thus the chlorophenol issue is not relevant in this case.
Finally, there is no water quality standw-d for phenol. only a recommendation of 300 ug/1. Phenol will not.
be limited at 300 ug/l for two reasons: (I) The value is only a recommendation (2) It is two orders of
magnitude higher than the 1.0 ug/I (had this standard been relevant).
MTBE will remain in the permit because of past MTBE problems. The BOD limit will also remain because
the facility appears to have occasional BOD problems (1 1/94). Xylene, 1,2-dichloroethane, fluorene,
naphthalene, phenantlirene, iron, and manganese monitoring will be added as part of the standardized
monitoring requirements for groundwater remediations.
In addition, Samar Bou-Ghazale mentioned (staff report) that perznittee is currently not discharging from
outfall 005 due to high MTBE levels. The effluent is being stored on site in a portable storage tank and is
hauled off site as needed for further treatment and proper disposal.
Storrnwater Discharge (Outfall 006)
In 1994, Amoco combined outfalls 002, 003, and 006. so that all Stormwater is discharged only through
outfall 006. A summary of Stormwater DMR data follows:
Date/ Flow pH TSS Oil&Gr Benzen Toluene Ethylbe Xylene Phenol MTBE
Outfall 1MGD nig/1 m u 1 uJl u01) &lj uR l u9/l
9401/002 0,00864 7.02 6 ND
9401/003 0,00864 7.20 7 ND
9402/003 0.00864 6.02 54 4 ND ND ND ND ND ND
9402/006 0.00864 6.15 8 3 ND ND ND ND ND ND
9403/003 0.00864 7.25 18 3 ND ND ND ND ND ND
9403/006 0.00864 7.0 24 2 ND ND ND ND ND ND
9404/003 0.00864 7.71 13 1 ND ND ND ND ND ND
9404/006 0,00864 7 2 ND ND ND ND ND ND ND
9407/006 0.00864 722 6 1 ND ND ND ND ND ND
9408/006 0.00864 6.54 4 ND ND
9409/006 0.00864 7.31 2 ND ND
9410/006 0,00869 7.22 10 ND ND
9412/006 0.00864 7.1 ND 2.3 ND
9501/006 0.00864 7.1 15 ND ND
9502/006 0.00864 6.9 ND ND ND
9503/006 0.00869 72 ND 4.3 ND
9505/006 0.00869 7.26 30 <5.0 1.43
9506/006 0.00864 7.0 9 <5.0 <1.0 <1.0 <1 .0 ND ND ND
9507/006 0.00864 7.6 11 <5.0 <0.010
9508/006 0.00864 7.33 6 <5.0 <0.010
9512/006 0.00864 7.20 11 <5.0 ND
9602/006 0.00864 6.78 <4.0 <5.0 ND
ND=not detected
The facility has passed all their toxicity tests during the last permit period and thus they will be required to
conduct the annual acute toxicity test.

NCG000518-5 Summary
,luly 26, 1996
Amoco is an oil terminal storage facility that discharges stormwater to a water supply classified receiving
water. Standard monitoring (as developed in the SOP) will be required for this stormwater discharge.

NCCG0005185 Summary 777�7
v
April 11, 1996\ f
Q-
\j
L-7
fil
IN =1 I U L UU U-,.LCU
The facility has passed all their toxicity tests during the last pti-init 1)(;1-10d alld IIILJS GICY Wifi i)C I-CLILIII.Cki to
conduct the annual acute toxicity test.
Amoco is an oil terminal storage facility that discharges stormwater to a water supply Classified receiving
water. Standard 4onitoring (as developed in the SOP) will be required for this stormwater discharge.
/2
Jl(1 iF �7 r�� -'7 Cf�;:�i f f� � !�(.U ;VJ' � ^,t /l��'t�^-(' 7 i''"� ' u°? r
7

W- b X-,)-
SOC PRIORITY PROJECT: Yes No X
To: Permits and Engineering Unit
Water Quality Section
Attention: Paul Clark
Date: April 9 , 1996
NPDES STAFF REPORT AND RECOMMENDATION
County: Mecklenburg
MRO No. 96-84
Permit No. NC0005185
PART I - GENERAL INFORMATION
1 . Facility and Address : Amoco Oil Company
Charlotte Terminal
P.O. Box 47308
Doraville, Georgia 30362
2 . Date of Investigation: 04-02-96
3 . Report Prepared By: Samar Bou-Ghazale, Env. Engineer I
4 . Persons Contacted and Telephone Number: Mr. Steve Jolley,
Terminal Operator; tel# ( 704 ) 399-6331
5 . Directions to Site: From the intersection of NC Hwy 27 and SR
1619 in the community of Thrift in western Mecklenburg County,
travel northwest on NC Hwy 27 approximately 100 yards . The
Amoco terminal is located on the right side of NC Hwy 27 .
6 . Discharge Point(s) . List for all discharge points :
Latitude: 35' 16' 59 " Longitude: 80' 56' 26"
Attach a U. S.G.S. map extract and indicate treatment facility
site and discharge point on map.
USGS Quad No. : F 15 SW USGS Quad Name: Mountain Island
Lake

7 . Site size and expansion are consistent. with application? -
Yes X No If No, explain:
8 . Topography (relationship to flood plain included) : Sloping at
the rate of 3 to 4% . The site is not located in a flood plain.
9 . Location of nearest dwelling: Several dwellings are located
within. 500 feet from the terminal .
10 . Receiving stream or affected surface waters : Unnamed tributary.,
to Long Creek.
a. Classification: WS-IV
b. River Basin and Subbasin No. : Catawba; 03-08-34''
C . Describe receiving stream features and pertinent
downstream uses : The receiving stream passes through
a mixed industrial and residential area prior to merging
with long Creek. There are seven known discharges to
Long Creek or an unnamed tributary to Long Creek. Of the
seven, five are oil storage terminal facilities .
PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
1 . a. Volume of wastewater to be permitted: Wastewater
discharges depend on rainfall .
b. What is the current permitted capacity of the wastewater
treatment facility? N/A
C . Actual treatment capacity of the current facility
(current design capacity) ? N/A.
d. Date(s ) and construction activities allowed by previous
Authorizations to Construct issued in the previous two
years : An Authorization to Construct was issued on July
5, 1994 for the construction of a groundwater treatment
system. An Authorization to Construct modifications was
issued on January 19, 1996 . The modifications consisted
NPDES Permit Staff Report
Version 10/92
Page 2

of the elimination of the fluid bed reactor and the
addition of an air stripping system for the existing
groundwater remediation system.
e. Please provide a description of existing or substantially
constructed wastewater treatment facilities : The
existing treatment facilities consist of a containment
area and an oil/water separator at the loading dock. The
groundwater remediation facilities consist of an
oil/water separator, a multimedia filtration system with
a clarifier, a bag filter ( 10 micron) , and six GAC
canisters for polishing. The off-site treatment
facilities consist of five recovery pumps , an oil/water
separator, a bag filter ( 10 micron) , and four GAC
canisters .
f . Please provide a description of proposed wastewater
treatment facilities : N/A
g. Possible toxic .impacts to surface waters : Discharges of
this nature have been shown to be toxic .
h. Pretreatment Program (POTWs only) : N/A.
2 . Residuals handling and utilization/disposal scheme : Sludge
from the oil/water separators and the groundwater treatment
system is to be tested and disposed of accordingly.
3 . Treatment plant classification (attach completed rating
sheet) : Proposed, no rating given.
4 . SIC Code( s ) : 5171
Primary: 53 Secondary: 66 ,
Main Treatment Unit Code: 53000
PART III - OTHER PERTINENT INFORMATION
1. Is this facility being constructed with Construction Grant
NPDES Permit Staff Report
Version 10/92
Page 3

Funds or are any public monies involved (municipals only) ?
N/A.
2 . Special monitoring or limitations ( including toxicity)
requests : Toxicity may need to be limited/monitored due to the
suspected toxic nature of such discharges .
3 . Important SOC, JOC or Compliance Schedule dates : (please
indicate) N/A.
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: N/A
Connection to regional Sewer System: N/A
Discharge to an infiltration gallery: N/A
5 . Air Quality and/or Groundwater concerns or hazardous materials
utilized at this facility that may impact water quality, air
quality or groundwater? Contaminated groundwater already
exists at the site. No hazardous materials concern. Air
quality permit for this site may be required by Mecklenburg
County.
PART IV - EVALUATION AND RECOMMENDATIONS
Amoco Oil Company is requesting an NPDES Permit renewal for
the discharge of treated wastewater. Stormwater as well as the
wastewater discharges from both oil/water separators (.loading
/unloading areas) drain to outfall 006 . Currently, the permittee
is not discharging from outfall 005 (groundwater remediation) due
to high levels of MTBE present in the effluent . At this time the
effluent is being stored on site in a portable storage tank and is
hauled off site as needed for further treatment and proper
disposal .
NPDES Permit Staff Report
Version 10/92
Page 4

It is recommended that the NPDES Permit be renewed once the
above mentioned concerns regarding toxicity have been addressed,
and comments from GW Section have been received.
/ G
Signature of `Rep rt Freparer Date
Water Quality :Regional Supervisor Date
NPDES Permit Staff Report
Version 10/92
Page 5