NC0004839_Permit (Issuance)_20010730

NPDES DOCVNENT SCANNIMO COVER SHEET
NPDES Permit: NC0004839
Document Type: Permit Issuance r
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Speculative Limits
Plan of Action
Instream Assessment (67B)
Environmental Assessment (EA)
Permit
History
Document Date: July. 30, 2001
Thin documerxt pri.xvted oa reuse paper-more any
4CA03tex1t ou the reYer0e IS:Rde

F W A rF Michael F. Easley
`pip 9PG. . ©�' Governor
r CD NR_ William G. Ross,Jr.,Secretary
North Carolina Department of Environment and Nalural Resources
< :.. .. Kerr T.Stevens, Director
- _
-- -
-- .._..,.,... - _. Divisionater Quality
July 30, 2001
Mr. Robert Gaston
ExxonMobil Refining and Supply Company
P.O. Box 82
Paw Creek. NC 28130
Subject: Issuance of NPDES Permit NC0004839
Charlotte Terminal
Mecklenburg County
Dear Mr. Gaston:
Division of Water Quality (Division) personnel have reviewed and approved your application for
renewal of the subject permit. Accordingly, we are forwarding the attached NPDES discharge permit. This
permit is issued pursuant to the requirements of North Carolina General Statute 143-215.1 and the
Memorandum of Agreement between North Carolina and the U.S. Environmental Protection Agency dated
May 9. 1994 (or as subsequently amended). Please note the following changes from your draft permit,
some of which are the result of the Paw Creek hearing officer's recommendations and others of which are
in response to the comments submitted by the facility:
• pH monitoring and limits have been removed from both outfalls 001 and 002. This was an error
made in all of the Paw Creek draft permits. The pH requirement was eliminated in the previous
permitting cycle and should not have been included in the 2001 permits.
• The MTBE limit of 11.6 µg/L has been removed from the permit. As per the hearing officer's
recommendations, a peer-reviewed criterion for MTBE does not exist and will not be included as part of
the permitting strategy for the Paw Creek permits. It is anticipated that a criterion will be in place
when this permit is next renewed. In addition to monthly monitoring of MTBE, please see Part
A.(4) for some additional requirements related to MTBE.
• The monthly monitoring requirement for naphthalene has been deleted from outfalls 001 and
002. Semi-annual monitoring using EPA Method 625 replaces it. As per the hearing officer's
report, 625 is the best method for detecting naphthalene and other middle distillate compounds and is
therefore a more appropriate monitoring requirement.
• Flow monitoring frequency for outfall 001 has been changed from monthly to episodic. As per a
request by the Mooresville Regional Office, flow must be measured with each discharge event.
• Phenol limits for outfalls 001 and 002 have been removed. The reasonable potential analysis
contained incorrect information regarding the allowable concentrations for phenol. The results of the
amended RPA show that there is no reasonable potential to exceed allowable concentrations.
• _ Benzene and xvlene limits have been removed for outfall 001. The reasonable potential analysis
was amended to consider only the data after the installation of the carbon filtration system for the
stormwater from the containment pad and loading racks area. The system began operating in
September 1999. Considering the data from September 1999 to December 2000 benzene and xylene
showed no resonable potential to exceed allowable concentrations.
• The limit for 1,2 Dichloroethane for outfall 002 has been removed and the monitoring frequency
has been reduced to semi-annually. The data for the last three years indicate that 1,2
dichloroethane has not been detected in the effluent.
• The monthly monitoring for fluorene and phenantherene has been removed from outfall 002.
EPA Method 625 will provide data for these parameters.
N.C. Division of Water Quality/NPDES Unit Phone:[phone]
1617 Mail Service Center,Raleigh,NC 27699-1617 tax:[phone]
Intemet:h2o.enr.state.nc.us DENR Customer Service Center. 1 800 623-7748

The monthly monitoring for iron and rntngan'*6 have been removed from outfall 002. The
primary treatment system for the groundwater is the air stripping unit. The carbon absorption units
are used as a polishing step. The requirement to monitor for iron and manganese would be necessary if
the carbon absorption unit was the only form of treatment for the groundwater to monitor the efficacy
......_.of the treatment sysfem"
If any parts, measurement frequencies or sampling requirements contained in this permit 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, and filed with the Office of Administrative Hearings
(6714 Mail Service Center, Raleigh, North Carolina 27699-6714). Unless such demand is made, this
decision shall be final and binding.
Please note that this permit is not transferable except after notice to the Division. The Division
may require modification or revocation and reissuance of the permit. This permit does not affect the legal
requirements to obtain other permits which may be required by the Division of Water Quality or permits
required by the Division of Land Resources, the Coastal Area Management Act or any other Federal or
Local governmental permit that may be required.
If you have any questions concerning this permit, please contact Teresa Rodriguez at telephone
number [phone], extension 595.
Sincerely,
Key ens /
cc: Mooresville Regional Office/Water Quality See tio
�NPDES t_Uni
Central Files
Point Source Branch Compliance and Enforcement Unit
Mecklenburg County Department of Environmental Protection
i

IA Permit NC0004839
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
` DIVISION OF WATER QUALITY
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
(NPDES)
In compliance with the provision of North Carolina General Statute 143-215.1,other lawful standards and regulations
promulgated and adopted by the North Carolina Environmental Management Commission,and the Federal Water Pollution
Control Act, as amended,
ExxonMobil Refining and Supply Company
is hereby authorized to discharge wastewater from outfalls located at the
Charlotte Terminal
6801 Freedom Drive
Charlotte
Mecklenburg County
to receiving waters designated as an unnamed tributary to Long Creek in the Catawba River basin in
accordance with effluent limitations, monitoring requirements, and other conditions set forth in Parts I,
II, III and IV hereof.
This permit shall become effective September 1, 2001.
This permit and authorization to discharge shall expire at midnight on June 30, 2005.
Signed this day July 30, 2001.
Kerr T. S vens, irector
Divisio of W er Quality
By Authority of the Environmental Management Commission

_ Permit NC0004839'
SUPPLEMENT TO PERMIT COVER SHEET
EgaonMobil Refining and Supply Company
is hereby authorized to:
1. Continue to discharge stormwater from the diked tank areas via Outfall 001; and
2. continue to operate a water pollution control system for the stormwater, fire system test water and
wash water from the containment pad and loading racks area consisting of:
• Oil water separator
• Retention tank
• GAC unit
and discharge from said water pollution control system via Outfall 001 located at the Charlotte
Terminal, 6801 Freedom Drive, Charlotte, Mecklenburg County; and
3. continue to operate a groundwater remediation system and discharge the treated waters consisting of:
• Oil/water separator
• Air stripper
• Carbon polishing unit
and discharge from said treatment system via Outfall 002 located at the Charlotte Terminal, 6801
Freedom Drive, Charlotte, Mecklenburg County; and
4. discharge from said treatment facility at a specified location (see attached map) into an unnamed
tributary to Long Creek, a waterbody classified as WS-IV waters within the Catawba River Basin.

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'._..J__.._ . Permit NC0004839
,#
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS._-
Beginning on the effective date of the permit and lasting until expiration, the Pertttee is4authorized to
discharge stormwater and wash,wa&er from OutfaI1001. Such discharges shall be limited and monitored
by the Pei�iii[teefas specified below:
EFFLUENTS Sz S tfc:�Y;Fy LIMITS�r;I-Q—z 2;J, 5 }xa,r�;MONITORING REQUIREMENTS ;
rr xr.�, ps u #kC r
v. +'M` 3 +}rf, sF}r�' : i ,
CHARACTERISTIC$.AF � ti MonthIy; r Daily Measurements ;Sample Sample Location
er:-j ,r .,:s. r.�. !."' rmw.w.Ci-!t .i^ r �y'•�""^ S J y l r
� � 5 ,.. , ,� ,t'
y� ,. ° , r :?., Avera e ` '� Maximum Fre uenca � �v4R
Flow,2 Episodic 2 Effluent
Turbidit 3 Quarterly Grab Effluent
Oil and Grease Monthly Grab Effluent
Total Suspended Solids 45.0 m Monthly Grab Effluent
Phenol Monthly Grab Effluent
Benzene Monthly Grab Effluent
X lene Monthly Grab Effluent
Toluene Monthly Grab Effluent
Eth lbenzene Monthly Grab Effluent
MTBE4 Monthly Grab Effluent
EPA Method 6255 Semi-annually Grab Effluent
Acute Toxicit 6 Annually Grab Effluent
Footnotes-
1. Samples shall be collected at the effluent discharge-pipe.
2. Flow — During periods of no flow, the Permittee shall submit a monthly Discharge Monitoring Report
(DMR) indicating "No discharge." Flow shall be monitored with each discharge event and may be
monitored in one of four ways:
a) measure flow continuously;
b) calculate flow based on total rainfall per area draining to the outfall; (this method of flow
measurement should not be used for facilities with large runoff-collection ponds);
c) estimate flow at 20-minute intervals during the entire discharge event; or
d) report flow based on discharge pump logs.
3. Turbidity —Effluent shall not cause receiving stream turbidity to exceed 50 NTU. If receiving
stream background turbidity exceeds 50 NTU, effluent shall not cause this background value to
increase.
4. MTBE - Please see Part A.(4) for other requirements relating to MTBE.
5. Once the facility has collected data for 8 consecutive sample events in which there have been no
detections above the method detection limit, the permittee may request a modification to the -
permit that reduces or eliminates the monitoring requirement.
6. Acute Toxicity (Fathead Minnow, 24-hour), Annual [see Special Condition A.(3)].
There shall be no discharge of floating solids or foam visible in other than trace amounts.
There shall be no direct discharge of tank solids,tank bottom water, or the rag layer.
There shall be no direct discharge of tank(or pipe) contents following hydrostatic testing unless benzene
concentration is less than 1.19 µg/l and toluene concentration is less than 11 fcg/I.

Permit NC0004839,:• :-
A: (2) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
�. . .._, .._ .. ...:,:,......_...,.. _,....-_..__,.._ ._.... .w......,.,._ _r.._.........._......._............_ _. ...,
Begirinitig on the effective date of the perinii and lasting untt2 expiration Athe Permittee is authorized to
discharge treated groundwater from Outfa11002:-`. Such discharges shall be limited and monitored by the
Permittee as specified below:
LIMITS. 16J .'y ' � N ;► ;i r , MONITORING REQUIREMENTS r ,.
- - Y t W ti"IlV
44Y:G.y_Ja Li4'3YSu" WV.YF' Y 'Y'f:h4L" 1'L , ahCtx' 3{;T
ICI RACTERISTICS � s�; Montlily .Dailyeasurement's i5ample' Sam le Location.,
��� �:+ :� °�i��-a a ��7('rvP:�'A�P._"�i4�u-. �C �` �t�'.`!"��r 4� "'+�,d'axJi .',�7�'ig'�} 1 ."u ',�,Ct �` ;�. ra s" : s = =Avera a Ma�amuFre uenc .�T e>t
F1ow2 0.057 MGD _ Episodic 2 Effluent
Turbidit 3 - Quarterly Grab Effluent
Oil and Grease Monthly Grab Effluent
Total Suspended Solids 30.0 mg/1 Monthly Grab Effluent
Phenol Monthly Grab Effluent
MTBE4 Monthly Grab Effluent
Toluene Monthly Grab Effluent
Benzene Monthly Grab Effluent
X lene Monthly Grab Effluent
Eth lbenzene Monthly Grab Effluent
1,2 Dichloroethane Quarterly Grab Effluent
Chloroform Quarterly Grab Effluent
EPA 6255 Semi-annually Grab Effluent
Footnotes:
1. Samples shall be collected at the effluent discharge pipe.
2. Flow — Flow shall be monitored with each discharge event. The permitee (or designated
representative) shall record the approximate time of flow measurements and calculate the
volume of treated wastewater discharged based on totalizing flow meter records.
3. Turbidity—Effluent shall not cause receiving stream turbidity to exceed 50 NTU. If receiving
stream background turbidity exceeds 50 NTU, effluent shall not cause this background value to
increase.
4. MTBE- Please see Part A.(4) for other requirements relating to MTBE.
5. Once the facility has collected data from 8 consecutive sample events in which there have been
no detections above the method detection limit, the permittee may request a modification to the
permit that reduces or eliminates the monitoring requirement.
There shall be no discharge of floating solids or foam visible in other than trace amounts.

Permit NC0004839
y t
a
EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
SPECIAL CONDITIONS
A. (3) ACUTE TOXICITY MONITORING (ANNUAL)
The'Permittee shall conduct annual toxicity tests using protocols defined as definitive in EPA Document
EPA/600/4-90/027 entitled "Methods for Measuring the Acute Toxicity of Effluents to Freshwater and
Marine Organisms." The monitoring shall be performed as a Fathead Minnow (Pimephales promelas)
24-hour static test. Effluent samples for self-monitoring purposes must be obtained below all waste
treatment. The permittee will conduct one test annually, with the annual period beginning in January of
the calendar year of the effective date of the permit. 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, DWQ Form AT-1 (originaI) is to be sent
to the following address:
Attention: North Carolina Division of Water Quality
Environmental Sciences Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Branch no later
than 30 days after the end of the reporting period for which the report is made.
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 dose/response 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 Water Quality indicate potential impacts to the receiving stream, this permit may be re-
opened and modified to include alternate monitoring requirements or Iimits.
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 and will
require immediate follow-up testing to be completed no later than the last day of the month following the
month of the initial monitoring.

y
Permit NC0004839
A. (4) MTBE SPECIAL CONDITION
For the protection of public health, oil terminals that discharge to waters classified as water supplies
("WS" waters) will adhere to the following action plan:
1. As stated in Part A. (1) and (2), monthly monitoring of MTBE for the duration of the permit is
required.
2. After one year of monthly monitoring or once twelve data points have been collected, the
Pern-duee shall review the MTBE data collected. If MTBE has not been detected in any samples
taken during the first year, the facility may request that the monitoring frequency for MTBE be
reduced. This should be done by requesting the NPDES Unit to perform a minor modification to
the NPDES permit. In the case in which MTBE has been detected within the first year of
effluent sampling, the subject facility must submit an MTBE reduction plan. This action plan
may include site-specific BMPs or engineering solutions. A copy of this plan should be
submitted to:
North Carolina Division of Water Quality
Water Quality Section
Attn: NPDES Unit
1617 Mail Service Center
Raleigh,NC 27699-1617
3. By the time of the next permit renewal, it is anticipated that surface water criterion for MTBE
will be established. This criterion will be used in conjunction with the facility's effluent MTBE
data to perform a reasonable potential analysis (RPA). The RPA will determine whether effluent
from a facility has the potential to exceed a water quality standard or criterion, thereby requiring
a water quality limit in the NPDES permit.

n�n nt:r=ctr rve>_rc HEAfRNG Ezra t",
,s yrk d3':TOBE HEIR BY r�t,jt,r#' L01
Meecklet bur �y THE NORTHCAROLINAENMIRONMENTALMANAGt3ft1W�MISSION
C _ 1e
�J r✓
y�SUBJECT A public hearing has been scheduled thing the p opused renewd 4nd Issuance bt
•tnc ldkrwing NfiOES Permds;. ¢*3�"s '�a , ,,,�",.
�i
r.pemttl nuriiber IV0002t982 to CITGO Pedoleum San FQ aie Paw Creek�Terrrsrul tOrateC in
Charlotte,N-C. Cha1W IMeWmburg County)for the discharge�s�mwater�ttb an unnamed u hvtary`,Io Gum
AFI'%Dt f V!T 0!YUBI.lCA7 8raneh
.; - 187 to Mo4'va Enterpr4is for the Paw 4',reek'ferininal,tocated in Charlotte
Permit nVen6Or tyCO022
NORTH CAROLIN A (Mecklenburg County)for ltie d sr3range ul stormwater and rertie illorl groundwater Inb an untamed
Inbutaryto Gum Branrh a '�'- .�,i`,,,1srkn:'aM3
MECKL.1;tdBUAO CUUNTY ..,�R perrrwl number NC0032B91 to Philips pipe U'neC.Company tar 11,e Chaddite.Terar nal fo6aled1h
Refore ffic undenrgned, N t"yt.-Charlotte[Medrlarrburg Caunly)for,the discharge of 5tormwater.fold an unnamed in utary to Gvm
NuM Csttct'ma,duly communan tt n T ii f }� �:t te�e{{,,,.,, x 1 'rat
trw to adFminuter osthr.P a11YgBraneh,x ,Y, "trL'q$. ¢ -s>- �r.
Shelby J. Cumin `s-."InumberNCO0747OSIaWikiamTemwrtalsHdtlngs,L_.P.fortheCharbttnJSouthemFadFities
Terminal lOrated in Chadalte(Mecklenburg County►fa*tube Wscftarge vF s�rmxrater mtd an unnamed
'It1E hR.h]m6urg 7ThIFS cv,tripulary to Paw Creek"ib"f ^ - ,-, k x�i._ty.r 1 art � ��„�,J�..» r�-•. ..
enlcred arr,ecand-clear m.rl,n the Cti},''Pemlit number NCOC-04723 to Valero Marketing drSupply Wlhpariy Jar the V21efo Marktif rig 8
and State Riaa:hdrbe it oath rtzedt Suppty,FarJkty�kfoaled m Chadatte(Medelen6ung County)for Ih!'diseharge'oftsronrtwaler into an
rteu:menq Rut the notice o,Fxr]e unnamed tn6utary to Paw.Geek v i ?#'f '.1µr,�. `'y"M; c�� -T• , .
NUT'.ICE OF PUBLIC ,4" Peniiftii 6erN000057711oTransMnntagneTerirxnaiing Fnc.fortheCharloHe/PawCreekTerrni-
nal p1 located in Charlotle'�("ktenhurg CuuntyJ for,the dschargeraf 5lormwatn into an unnamed
TO ZE HELD BY THE nbuSa [p Paw,Creek wsc»t `°�c`SA�a+f; 7 '^tt `'�' eF•-
ENV'.IRONHENTAL MANI:".' Permr[nuinber NCOO21971 to Trans"taigne Terrrtinatrpinc.btthe ChanaltelPaw Geek Terrtir
nil O2 hosted le CharI6t4-JMecklenbung County]for_ tlisrl arpg Of slokrmw2tnr h b an unnamed
tnlsutary to Paw Creek ErviK
Penrvt number NC003168I6 Culon'wl Pipeline Company far the Charlotte Oel�vdry Faalrt'y located'
.we copyol xhkh s atlached b—in Charlotte(Mecklenburg County)far tho dlsd,arge of sto mwdter fttb an un(7amed 1n6illay 1p Gum
.lerd;wa'RIIttF�r^un the follaxing del Btaneh
Ma rK h 16, 2001 ✓,t"., Perm t number NCpOgfi2i3 to Marathwn�4shland paholeum LlG itx the Mdratl,on Ashland Polio-,
leiim faraliylomit•d I'1 ChaAotte(Mecklenbur9 Count']for the dtsdtarge of sloimwater.lra4t1^an�un=
and N.e+he aid newrpapw awful named tributary fo Long Creek.'L## a ".,kr i"•»#.*Jdr ,e3,; 7.�
w k1t1 admtirmxrp au pvbfiaM`f Pemxl number N00046531.iO,Cr�oim Central FaetnOieum Carrrpany}orµttie Pdw Leek Tonninal.
every.arlh pu6licafion,anexrpapeY a{oCated mPaw GOek thAecklenburg County)ter the drsiyiarpe of s9plimvarer Into an unnamed Uibutary
and q�,tar�t nor se�+ian t.ss7rito Gum
C.ralina+.ndwua WI'ied sew.tr � �� i et'�s�#::,k�r �P"fi
qu p � Permn aiuel,ber NCOO46892 lo�rtosva Enrerpnses�LLC fpr.pla lTarldlte,Terminal Iocatetl in Paw
6-in -s3'.nf+he General Statues et Creek(Meckien6 rg County)for the A sChargesol slomtwafei and remedrated yroundwalei to an.
unnametl tributary tO Long Creek ra"�"•.ar- `�.�'tfa "Z'c'ate 1' ai. 2
ThG 16th daynf M -- 71
y 11,', ' -
tsgc PBRIIIt ntmiber NCfJO04839[o E>nronMobl Refinag 6SoppyCompany for,fiv Charlotte Tenrxrial
d ame elar
P to©hod In Cliarlo[te(Mecklenburg Gountyy for t,Che isd, bf rwwatar and remed�ated gm,6nd 7-3
Flan b an uttnerried lnbutary to Long Creekrt.Y t. °��•y-'k, �3r��`�'r" { ,
Sxomm and aehraribed 6fhi.l numbMNCODG5185 gstp Q aPawCrgeic7emunalbraled-
,n Pa Creek(Mecklenburg County)for tho d schaatW of sll4rmwater b an unnamed lnbutary m Lonp
16Lh dayaf March 201�Creekt7r` ��,.�.'�v.�����.1k1`i•��+'�ydrhF^ Se'r^;,,i�.h�T '+,� d�i�i'' G�w m<,.,,,�d+',a v,
U Pt1RPOSE Each cfthese fadldtes has appked fa ronewal d$,e1r NpDES PCrIfIi!fw the dfsd,arge:
ii of Sealed slortnMafer antVix ramadialed groundvraler him xa105 till tltd Cataw4a Arver basin,On they
' pi nary ppGorlbn bf7VCde 21 d1Cftgder 143;General Statutes of Nplt1j
*6UNotary Pualn bass of ekm staff review and a
Carding and titlter Wwtulslantlartlsantd ieguWhana,the North Cynfina En,rirdrtment Manaperneir{.
M C—iaion 6x 'Cammsslon prapoaesto Issue a NAO�S peeml for tldl faclkty,Euhiad fo apeciTk polutarit kr,ilFabmR'
Y Per' 7I7
-and a' at of Iha DlNsiorr dllttalcr;Oualdy and Regu}a6ais 15 NC4C 2hf Seiifort tyfWeiisub tloc.010hR7 MCGS 143-2a15 1(@M3}
m9eCnp
be held!O ne�Wtt au peersnent pubke ct>tm l at Yt4rdher b LL7Ge:maMfy or deity the permit r.�•a`
PROCEDURE'the hearing will lK cnnduetg f in tAe fiMowing rl a1rrarr p.{yi:r
ty The Orvisbn at W31er{Ouakry will prasen an a (Darolm rPiZhlh r bf the NoM. a Environment
.ManagementCann>asslass pempmatlure�* 1 ik'+•,. s�,c
.: vl6ng
The applicant may make an exptana6on at the acliw,!or xlutp pads perml is requfretl"?k F,�?�::, -
. ._Y,3 Puhtic,"ComrtrentrCamnersts-statements dataanU Ott"mtan:ab_dn Ybesubmttedinwnbng
P ar!o or durig the meet rig a may be presenletl orally at the m
in, ee fFPp,Perms doslrinq b speak wig _
d;rate this intdrd at the time of repis6alan'a[Iha maeiig Sa flat allpbsOns he's lino W Epeak may do._
-ito lengthy slalarneri hjy be fitrytEd at tl,a dtstzelio.Of 61e meet tg otBBer�Oral preaantagoPs.tfiat`
. exceed three nines snauld be acoodipaiuod by dxee 7�Mtte�n-onowe ,wfwth wiR be bled with Bmsinii
staff at the time of regishaGon vt` "Pkey �., {wW+, `r f't{ a,' " y. _
r4wCrOss b><arrrina[an of pers'pns preaenhng losstti rWy wlA r of Od allowed however,the headng
(otnur may ask ques6ans for dardfca6on'9.&P' *a°r y j1V r4...
it;YYJH k'Ap�rec�ad_P tie closed at th.ecantlu4aF of ow,me Qe6np�} r' R ".",�7'�i
' •1NHEAE,Ctiar101fe MetitlehburgGovernment Center
6O0 East FalaVl Sbae4 GH YET,,
I�Chatlone 1oMCarol�na-e HA � t� � � g ;(`
INFORMATION Acepy pi the dyad lJPOES pemagsfarda a sU,ar0efsl
x, rat map g the Gip' Of the tl' .
-are avallabie by wdang'pr-callang r 1 d ; .
�: M¢cnn de larkson (�'AM' i r 'r�4 rW- A ,r�k�.�N. A
u NCflvls and WatenOuallryrNP0E5 Unll '.� r• rn"'Str I�r�`l
.• 1617 Ma;l Spice Cent& ,.11 ��'' r:". �F'� 'v ✓�w�t ,,
Bale gM1 Nqr!,L.Carogna 27(99-16i7
70fiphone'number(919)733 3!0 61onsbn 536'4'.,t,'9
i, The app�irallons and other Intortnattoii are On foe at GteUlws an dMFaier G3uillip 512 North Salisbury
S6eel Aoom 925 df e tithdale Bulding in Bale di gh;°North Card'na grid at the fk+dsrm s Mooresaiile
.R'egonal0ffica(9t9 Nato Maul SVeetlei Monte -w,fVC]They maybe lnspeC[2d duringnomnaJoNce
oursi Co es n1 tt,eInfbrmahon on file•.are aVata6le updn leyilc5t and payment of the�rnsLv,of
- !
ieprotluceon"qtl such cpmmIn4 and roquestss nigardrng this matter shoultl make reference fo the
.y�rmd nurn6er(sl Irsted above mL Y3 ;'er ri.1- ;�',�.1r� l�i,f -
�:,, k

` 'DIVISION OF WATER QUALITY
April 5, 2001
MEMORANDUM
�s
TO: Dave Goodrich
am
FROM: D. Rex GIeason <o
PREPARED BY: Richard Bridgeman�, ¢ x—
wo
r as
SUBJECT: Draft Permits for Paw Creek Facilities
GS T-
Following is a discussion of the draft permits:
It is recommended that the effluent sample location be specified in all the permits.
Circumstances at one facility (at least) can be cited as justification for the
recommendation. The permit description of the water pollution control system (WPCS)
for Colonial Pipeline Co. (NC0031038) includes a retention pond. This pond is also
mentioned in the Fact Sheet. Regardless of the 7Q10, 30Q2, and average flow data, this
pond is actually an impoundment fed by three UT's to Gum Branch. According to the
terminal manager; there is flow in these UT's to Gum Branch 12 months per year. The
effluent from the CITGO (NC0021962) facility is discharged to one of the UT's.
Stormw-ater runoff from at least one other terminal site may also enter the impoundment.
Effluent samples arc collected at the outfall for the impoundment.
As discussed above, in addition to the sample collection location, the Colonial Pipeline
Co. (NC0031038) permit needs to be reviewed to determine if it is appropriate to include
the impoundment of a UT to Gum Branch as a treatment unit (retention pond).
Consistency is needed in specifying source of wastewater to WPCS.
There are four different methods used in the draft permits, as follows:
- Source not specified anywhere.
- Source indicated in the paragraph on the Supplement to Permit Cover Sheet,
which describes the WPCS and/or specifies outfaIl.
- Source indicated in the paragraph on the Supplement to Permit Cover Sheet that
specifies receiving water.
- Source indicated in Part I, Section A(1) of permit (Effluent Limitations and
Monitoring Requirements Sheet).
The writer's preference, in part because several of the facilities have multiple outfalls, is
to indicate sources on both the Supplement to Permit Cover Sheet (in paragraph which
describes the WPCS and/or outfall) and in Part I, Section A(1). An example of the
writer's preference is in the permit for Motiva Enterprises, LLC (NC0046892).

. I
Dave Goodrich ,
Page Two
April 5, 2001
Flow measurement/reporting frequency is recommended to be episodic (as in permit
Motiva Enterprises, LLC (NC0022187).
For several design reasons, discharge events basically occur on an as-needed basis; a
decision is usually made when there will be a discharge through an outfall. The only
exception may be Outfall 002 included in the permit for ExxonMobil Refining and
Supply (NC0004839), which is for a groundwater remediation system without any flow
retention capability, and, therefore, subject to daily discharges. Since discharge events
are mostly manually precipitated and occur randomly or as-needed, the range of the flow
data at a facility may vary considerably. Flow data seems to have played a large role in
the development of effluent limits (as in reasonable potential analysis for phenols), and
yet historically flow measurement methods and data have been two of the evaluations of
a compliance inspection subject to much scrutiny and criticism. Given the flow
measurement options specified in the permits, the small number of discharge events
probable each month, the importance of flow data, and the possibility of a wide range in
the flow data, it is not unreasonable to expect flow to be measured and reported for each
flow event.
The Turbidity monitoring requirement does not seem to be complete.
The permits, with two exceptions (discussed under the next item), include either a
quarterly monitoring-only requirement or a monthly monitoring requirement with an
effluent limit. It is not understood how the effluent turbidity monitoring requirement
correlates with the relevant footnote in Part I, Section A(1). Should there not also be an
upstream and downstream monitoring requirement. In fact, those facilities with a
monitoring-only requirement need only conduct stream monitoring to determine if
effluent turbidity levels result in stream standard violations.
- One of the exceptions mentioned above under the item for Turbidity Monitoring is
Marathon Ashland Petroleum, LLC (NC0046213). Although the permit cover letter
indicates that the permit includes a monthly monitoring requirement and an effluent limit,
Part 1, Section A(l) of the permit and the Fact Sheet indicate a monthly monitoring-only
requirement. The permit and Fact Sheet appear to be correct; monthly monitoring is
being required because of the near potential for a stream standard violation...The other -- --
exception is Motiva Enterprises, LLC (NC0022187); monthly monitoring is being
required because none of the previously required monitoring has been conducted.
- Philips Pipe Line Company (NC0032891)—Phenol Iimit in the other permits is expressed
in mg/L. In the Philips permit,_it-is.expressed;in-ug/l:— ---
ExxonMobil Refining and Supply (NC0004839)—Benzene limit is indicated to be 1.2
ug/L; should it not be 1.19 ug/L?

Dave Goodrich ...
Page Three - =
April 5, 2001
Phenol limit development.
The cover letters for four of the six permits with a Phenol limit discuss development of
the limit. In the cover letter, the water quality standard for phenol is indicated to be 1
mg/L; it is actually 1 uglL for WS waters. The writer is not familiar with the 2001 SOP
used to develop limits for phenol, but considering the fact that five of the six facilities
discharge to streams having a 7Q10, 30Q2, and average stream flow of zero, and the sixth
facility discharges to a stream having a 7Q10 and 30Q2 flow of zero and an average flow
of<1, it is hard to understand the assigned limits. The 3 mg/L Phenol limit for Outfall
002 in the ExxonMobil (NC0004839) permit is almost unimaginable.
- Motiva Enterprises, LLC (NC0022187)—The Fact Sheet indicates that there is a
reasonable potential for the stream standard for Lead to be violated, but indicates that no
limit will be assigned because lead is an action level pollutant. A change? If not, should
there be a Lead limit in permit?
- TransMontaigne Terminaling, Inc. (NC0021971)—Permit Cover Sheet indicates that
discharge is to Paw Creek. As indicated elsewhere in permit, discharge is to a UT to Paw
Creek.
- Williams Terminals Holdings, L.P. (NC0074705)—The permit description includes an
oil/water separator, a carbon filter, and a holding tank. The Fact Sheet indicates that
wastewater and stormwater are routed to a retention pond and released as needed. No
staff report or compliance inspection report mentions this retention pond. MCDEP staff
has confirmed that there is no retention pond at the site.
Valero Marketing & Supply Co. (NC0004723)—Please review discussion in Fact Sheet
concerning the assignment of a Turbidity limit. If the average turbidity value in the past
1.5 years is 7.2 NTU and the maximum 28 NTU, why is there a prediction of a maximum
of 110.3 NTU?
- Williams Energy Ventures (NC0005185)—Permit Cover Sheet indicates that discharge is
to a UT to Gum Branch; as correctly identified on the Supplement Sheet, it is a UT to
Long Creek.
- Motiva Enterprises, LLC (NC0046892) --Fact Sheet indicates that the Flow requirement
for Outfall 002 in the previous permit will remain unchanged. There was a Flow limit in
the old permit, but not in the draft permit. The writer does not recommend a limit.
Please advise if you have questions or comments.
RMB

ts u"a
� � O
U � G
h RECEIVED
y4'i'Lr7 WATM nt ra nv cF:rnON
�TN CA�0 n
MECKLENBURG COUNTY
APR ?�?1
Department of Environmental Protection Non DiwA�aroe Permlt#hg
April 17, 2001
Mr. Dave Goodrich
NCDENR - D WQ - NPDES Unit
1621 Mail Service Center
Raleigh, NC 27699-1617
Subject: Paw Creek Petroleum Terminal NPDES Permit Renewals
Dear Mr. Goodrich:
The Mecklenburg County Department of Environmental Protection (MCDEP) has reviewed the
subject draft permits. As you know. MCDEP has a Memorandum'of Agreement with the
Division of Water Quality to conduct inspections of the Paw Creek terminals in order to
determine compliance with the applicable NPDES permits. We offer the following comments
regarding the permits:
Genera!
• Flow Measurement
The flow measurement method by which facilities are allowed to calculate flow based on
the area draining to the outfall. the built-upon area, and total rainfall using the rational
equation is inaccurate in most cases. Most facilities inspected by MCDEP collect
stormwater in earthen secondary containment basins surrounding the above ground
storage tanks (not ponds). The facilities generally hold the storm-water for as long as
possible (several weeks if weather permits) to allow any suspended solids to settle out
�. and to avoid discharge if possible so that monthly sampling and laboratory analysis does
not have to be performed. Calculating discharge flow by this method is inaccurate
because it does not account for evaporation and ground infiltration during the holding
period.
• Quarterly Turbidity Monitoring
The permits state that "Effluent turbidity shall not cause the receiving stream turbidity to
exceed 50 NTU. If receiving stream background turbidity exceeds 50 NTU, effluent shall
not cause this background value to increase."
PEOPLE • PRIDE • PROGRESS
700 N. Tryon Srreei - Suire 205 - Charlotte, NC 28202-2236 - (-04) 336-5500 - Fax [phone]

r r
Mr. Dave Goodrich
Paw Creek Petroleum Terminal NPDES Permit Renewals
April 17, 200I
Page 2
The permits require quarterly turbidity monitoring at the effluent. The permits do not
require upstream or downstream monitoring for turbidity. Without instream monitoring
requirements. compliance cannot be determined.
Individual Facility Comments
• Williams Terminals Holdings, L.P. - Permit # NC0074705
An error was noted on the fact sheet for this facility. The background section refers to a
detention pond which is used to hold wastewater prior to discharge. MCDEP has
determined that the treatment works for this facility do not include a detention pond.
• L
obil Refining and Supply Company- Permit # NC0004839
01-
y maximum permit limit for benzene is listed as 1.2µg/I. The North CarolinaJ)
ality standard for WS-IV waters is 1.19µg/l.
__
• Marathon Ashland Petroleum, LLC - Permit # NC0046213
The last footnote on the Effluent Limitations and Monitoring Requirements
page of the permit states, "There shall be no direct discharge of tank (or pipe) contents
following hydrostatic testing unless benzene concentration is less than 71.4µg/l and
toluene concentration is less than I lµg/l." Since the receiving stream is a class WS-IV
water, the benzene limit should be 1.19µg/l.
• Colonial Pipeline Company - Permit # NC0031038
MCDEPs past inspections of this facility indicate that the retention pond located on-site
- receives flow from three intermittent streams.^ While the streams are classified as
intermittent by USGS, terminal personnel have indicated that the streams have perennial
flow. In addition, stormwater discharges from the Citgo facility (NC0021962) and Crown
Central Petroleum Corporation (NC0046531) flow to Colonials' retention pond before
entering the receiving stream. Since these conditions exists prior to the outfall location
(sampling point), MCDEP has concerns that these influences may constitute dilution of
the waste stream and effluent analysis may not be totally representative of the facility's
wastewater characteristics. in addition, Colonial could potentially be liable for impacts
from off-site sources.

Mr. Dave Goodrich
Paw Creek Petroleum Terminal NPDES Permit Renewals
April 17, 2001
Page 3
If you have any questions regarding these comments, or any other matters, please feel free to give
me a call at 704/336-5500. Thank you.
Sincerely,
i
R1/ ozzeIIe I-','
Water Quality Program Manager
I
I
I
cc: Teresa Rodriguez - DWQ
Natalie Sierra - DWQ
Derrick Harris - MCDEP

NORTH CAROLINA
PETROLEUM
COUNCIL
A D( Ufari of the Amerkan Peftleum hudtzu
WILLIAM I1.wI.,4liiGit_gmom SUITE 285D * 150 FAY=V1L1Z 5r.MALL
EXCUMN ova RALEIGF.NC 27601
919/e28-s43e • FAX01G)MI CMS
May 2, 2001
Mr.Rick Shiver
Water Quality Regional Supervisor
Division of Water Quality
NC DENR
127 Cardinal Drive Ext.
Wilmington, NC 28405-3$45
Re: NPDES Pcrmit Renowals
Paw Creek Petroleum Pipeline and Distribution Terminals
Charlotte(Mecklenburg County), North Carolina
Dear Mr. Shiver:
Thank you for.the professional m€tmer in which the public hearing on the petroleum terminals'
NPDES permits was conducted in Charlotte on April 19,2001.
The purpose of this letter—which I request be included in the official hearing record—is to
express my members' strong concern about the way MTBE is being addressed in the terminals'
draft permits.
The North Carolina Petroleum Council—a division or the American Petroleum Institute,the
trade association for the nation's major fuel suppliers—is committed to insure that the
opportunity for public;hearings and comment is an integral part of government decision-making.
So we simultaneously praise the process that allows us to submit this statement for the record,
while we point with alarm to the proposed MTBE limit of 11.6 uglL that has been included in the
draft permits without a single hearing or any official review by a rulemaking body.
We asked the Department(DENR)to help cis understand how this limit came about. We wets~
told that there is no surface-water standard for MTBE. Further,we were advised that the
proposed MTBE limit has not been endorsed by the Environmental Management Commission—
has not been debated by those publicly appointed members—has not been the subject of public;
hearings at all. In fact, the EMC recently dealt with the matter of MTBE and voted not only to
reject a request for a temporary groundwater standard of 70 ppb, but also to reafflrm'the value of
public hearings by calling for a permanent rulemaking process to tighten the MTBE groundwater
%%WAW& So a%-sc aril awaii ttvz VWai nS pTo—,r4 on that V►uspo"we are now confronted with

Sent By: ; 919 821 0337; May-2-Q1 16:32; Page 313
Mr. Rick Shiver
May 2,2001
Page 2 - _......... ....
draft NPDES permits that attempt to install an MTBE limit that is at best controversial and at
worst a circumvention or the EMC.
It is my understanding that MTBE was not an issue for the Department in the NPDES permits
issued five years ago.
To be sure,in the intervening years it has been an issue of increasing attention,study,debate and
speculation. Apparently some individuals have been so moved by the growing debate that hasty
changes in risk calculations and other values have occurred. A few advocates within the
Department who sounded the alarm so vigorously in statements to the EMC to support of an
MTHE groundwater standard of 74 ppb have now changed their minds! What had been a
certainty one month was abandoned the next in favor of a new calculation—and a new limit
level. So, if public health considerations are truly moving this &,4t, it numbers are hastily
abandoned and recalculated, if the science is in such a state of flux,then our commitment to
reasoned public input is all the mare appropriate and needed to inqure that the calculations of
today are not abandoned tomorrow.
Recommendations
The Council's members accept that an MTBE limit that has been peer-reviewed and duly
considered via the rulemaking process may be appropriate for inclusion in the terminals'NPDES
permits. Lacking that,however, the Council believes the NME limits contained in the draft
permits should be removed.
Importantly,the Council's members with facilities in Charlotte are willing to help the
Depmfirnent collect MTBE data by monitoring for it on a periodic basis. But the proposed
monthly monitoring requirement is excessive. We are confident that semi-annual rnonitorin by
each of the terminals will provide the needed representative.data to£o=the basis for future
decision-making.
Sincerely,
I
William H. Weatherspoon
W H W/jtn - ---- -- _ - - - - ... - _..._..._.-._ .- _.....
c: Ms. Natalie Sierra

SURFACE WATER QUALITY STANDARDS OR CRITERIA FOR PETROLEUM-RELATED CONTAMINANTS
"C" & "B"WATERS
(ugll unless noted "WS-11. -"WS-V" WATERS (ug11 unless SOURCE OF STANDARD
CONTAMINANT CAS# otherwise) WATERS noted otherwise) OR CRITERIA
BENZENE 71-43-2 71.4 1.19 71.4 15A NCAC 2B .0211-.0222
n-BUTYL BENZENE 104-51-8 36 36 36 ECOTOX 4198
sec-BUTYL BENZENE 135-98-8 41 41 41 ECOTOX 4198
CHLOROFORM 67-66-3 470 5.7 470 EPA 4122/99
ETHYL BENZENE 100-41-4 383 524 130 ECOTOX 1101
IPE 108-20-3 19 mg/L 19 330 mgll ECOTOX 1/01
ISOPROPYL BENZENE 98-82-8 316 186 4.6 mg1I ECOTOX 1101
p-ISOPROPYL BENZENE 99-87-6 325 325' 1.1 mg/1 ECOTOX
METHYLENE CHLORIDE 75-09-2 1600 4.7 1600 EPA 4/22/99
MTBE 1634-04-4 2393 11.6 2393 NC DHHS 7111/00 --
NAPHTHALENE 91-20-3 105 43 64 ECOTOX 1101
n-PROPYL BENZENE 103-65-1 77.5 77.5 190 ECOTOX 1101
1,2,4-TRIMETHYLBENZENE 95-63-6 386 72 218 ECOTOX 1101
1,3,5-TRIMETHYLBENZENE ' 108-67-8 626 100 215 ECOTOX 1101
15A NCAC 2B .0211-
TOLUENE 108-88-3 11 (0.36 Tr) 11 (0.36 Tr) 185 .02221ECOTOX 8199(SW)'
XYLENE, TOTAL 1330-20-7 88.5 88.5 370 ECOTOX 1101
Criteria which have a source of EPA ECOTOX were developed using EPA's ECOTOX database per 15A NCAC 213 .0208.
Last update 212101 (DMR) These concentrations are updated regularly.
Questions or criteria for other parameters not found in the 15A NCAC 2B .0200s can be addressed to Dianne Reid at
919.733.5083 extension 568 ([e-mail]) OR Jason Wynn ext. 351 ([e-mail])
i

Permit Requirements for Dischargcs fr9W Oil & Petroleum Storage Facilities
2001 Permitting Strategy
Background [_Introduction
In 1996, the Permits and Engineering Unit reviewed NPDES permit monitoring requirements for stormwater
discharges at oil terminal facilities located in the Greensboro and Charlotte areas. This review revealed
inconsistencies in monitoring requirements that were subsequently discussed with staff of the Winston-Salem
and Mooresville regional offices. These discussions and a review of past information collected at these facilities
formed the basis for much of the standard monitoring requirements contained in this Standard Operating
Procedure (SOP) for Stormwater Discharges from Oil Terminal Facilities.
In accordance with the basinwide planning schedule, the NPDES permits for the oil terminal facilities are due for
renewal in 2001. The NPDES unit has reviewed the discharge monitoring reports (DMRs) for the facilities in
order to assess the SOP currently in place. This led to some revisions and additions to the existing procedure,
the bulk of the 1996 SOP will be carried over into the 2001 revised SOP.
This document is divided into three sections that delineate the permitting requirements for oil terminal facilities.
The first part describes the minimum requirements for all oil terminal facilities in the state - both monitoring
requirements and permit limits. The second section describes potential additional site-specific requirements that
are based upon the performance of a reasonable potential analysis for the facility. Such requirements are based
upon reported data from the Discharge Monitoring Reports (DMRs) of a given facility. The third and final section
delineates additional requirements for those facilities which discharge to receiving waters carrying a water supply
classification.
I. Minimum Requirements for ALL Oil Terminal Facilities
A. Flow
Episodic Monitoring (monitor with each discharge event)
Measurement of flow is to be representative of a discharge event. Many oil terminal facilities
have storage ponds to collect runoff and therefore, discharges may not always occur during
storm events. Flow should be monitored by one of the following methods:
1. Measure flow continuously, or
2. Calculate flow based on the area draining to the outfall, the built-upon area, and the total rainfall,
using the rational equation (see below), or
3. Estimate by flow measurement at 20 minute intervals during the entire discharge event, or
4. Base flow on pump logs.
The rational equation: Q=KuCIA, where
Q = flow (peak flow rate (cfs or m3/sec)
Ku = units conversation factor = 1.008 for U.S. standard units (usually ignored because it is so close to
1), or 0.278 for SI units
C = dimensionless runoff coefficient for the watershed, loosely defined as the ratio of runoff to rainfall
I = intensity of rainfall taken from the intensity-duration-frequency curves for the specified design
return period at the time of concentration tc, (in/h or mm/h)
tc - time of concentration - time after the beginning of rainfall excess when all portions of the drainage
basin are contributing simultaneously to flow at the outlet
A area of tributary watershed (acres or km2)
The rational equation is used to calculate the runoff from a region, given:
➢ the runoff coefficient which accounts for infiltration and other potential losses in the region,
➢ the rainfall intensity to the region,
➢ the time it takes for runoff to travel from the region's upper reaches to its outlet, and
➢ the region's drainage area.
For oil terminal facilities with large storage ponds that serve to collect runoff, item 2 listed above and the
rational equation should not be used because the calculations will determine the flow to the storage pond,
rather than the flow from the pond.
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Permit Requirements for Discharges f&bm Oil &'Petroleum Storage Facilities
B. Acute Toxicity: Fathead Minnow (Pimephales promelas) 24-hr, Annual
Monitor annually (assuming first five discrete storm events have already been monitored and
showed no toxic effects) - - - - r
Monitoring Footnote: acute tonicity monitoring should occur during collection of BTEX
parameters (see item E below)
Products stored at oil terminals may contain a variety of different chemicals (some of which may have
harmful or toxic effects). To verify that toxic chemicals are not discharged to surface water, a periodic
toxicity test will be required. An acute, rather than chronic, toxicity test is required because oil terminal
facility discharges are typically short-term, episodic events. Specifically, an acute 24-hour pass/fail at 90%
waste concentration using fathead minnows is the recommended toxicity test for stormwater discharges.
Facilities that meet one or more of the following criteria will not qualify for annual monitoring and will
be required to monitor for acute toxicity during five storm events:
1. Facilities that have never monitored for acute toxicity during a storm event, or
2. Facilities that monitored for acute toxicity during four or fewer storm events during the last
permit period, or
3. Facilities that completed five acute toxicity tests during five storm events, but did not pass all
five tests.
Facilities that fail an acute toxicity test conducted during one or more of the five storm events or during an
annual monitoring event will be required to conduct quarterly monitoring for the forthcoming permit period,
and must receive State approval for reduced monitoring. For facilities that have not yet conducted acute
toxicity testing for the first five discrete storm events, a statement in the permits will allow for additional
toxicant limits should the toxicity test indicate toxic effects. At the time of permit renewal, only annual
monitoring for toxicity would be required if the facility has performed the five discrete sampling
requirements with no acute toxicity.
C. Total Suspended Solids
Monitor monthly
Daily maximum 45.0 mg/l
Historically, Total Suspended Solids (TSS) has not been a significant problem in stormwater discharges at
oil terminal facilities. A 1996 analysis of TSS data from five stormwater discharges indicated only one event
in excess of the previously permitted 30.0 mg/1 monthly average. A daily maximum limit of 45 mg/L is
recommended as a general indicator of stormwater quality. A daily maximum compliance period is given to
reflect the sporadic nature of these discharges. Should TSS monitoring data indicate any substantial
problems, the Regional Office or county may elect to enforce the instream standard for turbidity.
D. Oil and Grease
Monitor monthly - No Limit
Monitoring Footnote: Where possible, the grab sample for oil and grease should be skimmed from
the water surface of a quiescent (calm water) zone.
-- Historically; oil and grease has not been a significant problem in stormwater discharges at oil terminal
facilities. However, like TSS, oil and grease is a good general indicator of the quality of a stormwater
coming from a site. Where possible, oil and grease samples should be skimmed from the surface of a
quiescent zone closest to the discharge.
E. BTEX
Monitor monthly — No Limit
Benzene, toluene, ethylbenzene and xylene are toxicants commonly found in petroleum. The previous
permitting strategy for the oil terminals required the EPA 624/625 scan, which, among other contaminants
of concern (see Part II), detects BTEX compounds. A review of the discharge monitoring report data from
the previous permitting cycle indicates that these four contaminants frequently appear in stormwater from
terminal facilities. For the most part, the other volatiles and semi-volatiles detectable by the EPA 624/625
Page 2 of 8
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Permit Requirements, for Discharges frpm Gil & Petroleum Storage Facilities
scan were never detected in the stormwater from these facilities. By monitoring for BTEX and naphthalene
(see part F. below), the facilities are collecting data on those pollutants that are mostly likely to be present
in the'water.
F EPA Method 625.'.-"
Monitor semi-annually
The intent of this monitoring requirement is to monitor for naphthalene and other indicators of middle
distillate compounds detectable by Method 625. These contaminants are commonly found in heavy
fuels, such as diesel. During site visits of terminal facilities performed by members of the NPDES Unit,
it was observed that the majority of the terminals reserve at least one storage tank for diesel fuel.
Originally, facilities were to have monitored only for naphthalene, but since the'most accurate method
of quantifying naphthalene is through Method 625 and other middle distillate compounds can be
detected through this scan, the entire results should be reported to the Division.
If it can be demonstrated by the permittee that diesel fuel is not currently being stored on site, then the
monitoring requirement on the effluent page will have the following footnote:
'Monitoring requirement applies only for facilities storing diesel or other heavy fuels on site."
G. Tank Solids, Tank Bottom Water, and Rag Layer
No direct discharge of tank solids, tank bottom water, or the rag layer is permitted.
There are typically four discrete layers of varying thickness within a storage.tank. At the very bottom of the
tank is the solids layer that achieves a 1/2-1 inch thickness over a 5-6 year period. Immediately above the
solids layer is 1-6 inches of tank bottom water that results from rainwater breaching the wall seal in open
roof tanks. Open roof tanks are not completely open, but have a roof floating directly on the product.
There is a seal between the tank walls and floating roof designed to prevent water from entering the tank.
Water breaching this seal and entering the tank is referred to as tank bottom water. The rag layer is at
most 3/4 inch thick and forms the interface between the tank bottom water and the product. The product
is the topmost layer and is 20-25 feet. Normally, the tank bottom water is removed from the tank when it
is 3-4 inches deep. The mixture of water and product in the rag layer is often drawn off when tank water is
removed because water entering tanker trucks must be minimized. As a result of potentially high levels of
organic compounds in the three bottom layers of storage tanks, they are not to be discharged, but instead
should be transported off-site for appropriate treatment and/or disposal or treated/recovered onsite if
treatment technology capabilities occur onsite.
H. Hydrostatic Testing
Hydrostatic testing of oil tanks normally occurs once every five to six years. Prior to the hydrostatic testing,
the tank is completely drained and tank bottom materials are handled as described in the previous section.
The tanks are completely cleaned and then coated and welded (if necessary). The tank is then filled with
water for the hydrostatic test. Some oil terminal facilities use stream or lake water to hydrostatic test their
tanks, while others use potable city water. Because the tank is thoroughly cleaned prior to refilling with
water for the hydrostatic test, water discharged from the tank following the hydrostatic test should be fairly
clean. However, tank discharges following hydrostatic testing may contain contamination. Therefore,
monitoring of the tank water prior to direct discharge will be required. There shall be no direct discharge
from oil terminal facilities following hydrostatic testing if concentrations of benzene and/or toluene are
greater than their respective water quality standards (see effluent pages at end of SOP for details).
I. MTBE Monitoring
Monitor monthly
Within the last year, the Environmental Protection Agency has recommended banning methyl tertiary butyl
ether (MTBE), an ingredient commonly used in gasoline to aid in the reduction of air pollution. MTBE was
originally added to gasoline in response to a 1990 law that required higher oxygen content in gas sold in the
most-polluted cities. It has since become a cause for concern since the EPA now believes that MTBE may
be a carcinogen and is seeking to outlaw the compound.
Since MTBE contamination of water is a public health concern, monthly MTBE monitoring will be added to
all facilities. For those facilities currently monitoring for MTBE, reasonable potential analysis will be
performed to assess the need for an MTBE limit. In non-water supply waters; the instream MTBE standard
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Permit'Requirements for Discharges,fram' ' Oil & Petroleum Storage Facilities
is 2393 Jig/L, and is unlikely to be violated. All facilities discharging to water supply waters will have a
special condition added to the permit that pertains to MTBE monitoring and source reduction (see Part
-_.. - -.. _
II..- ' Additional Site-Specific Rcquiremcnts
A. EPA Method 624
Monitor semi-annually
The entire 624/625 scan was originally included in the SOP to assess which of the petroleum-associated
organic chemicals are found in stormwater. These tests scan for volatile and semi-volatile organics and
cost approximately $700 to run (Ray Kelling, personal communication 2/14/01). Currently, the oil
terminal facilities are performing the scan twice a year. Most facilities obtain results consisting entirely of
non-detects, but a few have detected one or more of the compounds on the 624/625 list. Tables 1 and 2
summarize the compounds included in the scans and note those parameters detected during the last
permitting cycle. .
After a review of the data and discussions with different members of the Division of Water Quality Point
Source Branch, it has been decided to assign semi-annual monitoring using EPA Method 624 to any of the
facilities that detected any compound listed in Table 1 that is not benzene, toluene, ethylbenzene, xylene or
naphthalene (as these were found in most discharges and are covered by monitoring requirements listed
above).
Table 1. Compounds detectable by EPA Method 624
PARAMETER DETECTED IN OIL TERMINAL W.
Acrolein
Acrylonitrile
Benzene ./
Bromodichloromethane
Bromoform
Bromomethane
Carbon tetrachloride
Chlorobenzene
Chloroethane ✓
Dibromochloromethane
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
1,1-Dichloroethane
trans-1,2-Dichloroethene
1,2-Dichloro ro ane
cis-1,3-Dichloro ro ene
trans-l,3-Dichloro ro ene
Ethyl benzene J
Methylene chloride J
1,l,2,2-Tetrachloroethane
Tetrachloroethene
Toluene
1,1,1-Trichloroethene
1,1,2-Trichloroethene
Trichloroethene
Trichlorofluoromethane
Vinyl chloride
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Permit Requirements for Discha,rges from Oil & Petroleum Storage Facilities
Table 2. Compounds`detectable by EPA Method 625'
PARAMETER DETECTED IN OIL TERMINAL STORMWATER?
Acena hthene
Acena hth lene
Anthracene-
Benzo a anthracene
Benzo b fluoranthene
Benzo k fluoranthene
Benzo a rene
Benzo(ghi)perylene
Benzyl bujyl phthalate
Bis 2-chloroeth 1 ether
Bis 2-chloroetho methane
Bis 2-eth the 1 hthalate
Bis 2-chloroiso ro I ether
4-Bromophenyl phenyl
ether
2-Chlorona hthalele
4-Chlorophenyt phenyl
ether
Chrysene
Dibenzo a,h anthracene
Di-n-butylphthalate
1,3-Dichlorobenzene
1,2-Dichlorobenzene
1,4-Dichlorobenzene
3,T-Dichlorobenzidine
Diethyl phthalate
Dimeth 1 phthalate
2,4-Dinitrotoluene
2,6-Dinitrotoluene
Di-n-octylphthalate ./
Fluoranthene
Fluorene
Heptachlor
Hexachlorobenzene
Hexachlorobutadiene
Hexachloroethane
lndeno 1,2,3-cd rene
Iso horone
Naphthalene J
Nitrobenzene
N-Nitrosodi-n-propylamine
PCBs
Phenanthrene J
rene
Toxa hene
1,2,4-Trichlorobenzene
4-Chloro-3-meth I henol
2-Chloro henol
2,4-Dichloro henot
2,4-Dimeth 1 henol
2,4-Dinitro henol
2-Meth 1-4,6-dinitro henol
2-Nitro phenol
4-Nitro phenol
Pentachloro henol
Phenol J
2,4,6-Trichloro henol
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Permit Requirements for Discharges frdin Oil & Petroleum Storage Facilities
B. Reasonable Potential (General)
_ The reasonable potential procedure is a method used to determine the potential of a discharge to violate a
water quality standard for a given parameter based on existing data. If a parameter is determined to have
reasonable potential to violate a water quality standard, a limit and monthly monitoring will be required. A
parameter is determined to have reasonable potential to violate a water quality standard if a calculated
maximum predicted effluent concentration is greater than the allowable effluent concentration.
Reasonable potential is determined by performing a statistical analysis for each parameter of concern that
has either a state or federal water quality standard. For each parameter, the statistical analysis works best
with a minimum of eight to twelve data points (from DMRs) although the more data points used, the more
accurate the analysis. The statistical analysis allows one to calculate a maximum predicted effluent
concentration based on the existing data set. A step-by-step procedure for determining whether or not a
parameter should be limited based on reasonable potential determination follows:
STEP
1. Determine the number of sample points (n)
2. Determine highest value from data set. Best professional judgment should be used by the reviewer so
as not to use an outlier. Since an outlier will not be determined statistically, maximum values should
rarely be discarded in this analysis.
3. Determine the coefficient of variation (CV = STD DEV/MEAN)
4. Determine the appropriate multiplication factor to be used by comparing the number of samples versus
the co-efficient of variation (see Table 3-1)
5. Multiply the highest value from the data set (Step 2) by the multiplication factor determined in step 4 to
obtain the maximum predicted effluent concentration.
6. Compare the value from Step 5 (the maximum predicted effluent concentration) with the allowable
effluent concentration, which is based on instream dilution and the corresponding water quality
standard. EPA recommends that permitting authorities find reasonable potential when the maximum
predicted effluent concentration is greater than the allowable effluent concentration.
A spreadsheet has been developed to expedite this analysis. It is titled "Toxicant Spreadsheet" and is
located on the NPDES server. The spreadsheet requires the input of the facility name and permit number,
the waste flow (Qw), 7Q 10 flow, pollutant name, state or federal water quality standard, and the DMR data
points with appropriate units. The spreadsheet then computes the standard deviation, mean, and
coefficient of variation for the entered data points. The coefficient of variation is then used along with n
(the number of data points entered in the spreadsheet) to determine the Multiplication Factor. This
Multiplication Factor is entered into the Toxicant Spreadsheet to calculate the maximum predicted
concentration.
If the maximum predicted effluent concentration is greater than or equal to the allowable effluent
concentration, (or in other words, if there is reasonable potential for a water quality standard violation), the
parameter should be limited (as a daily maximum) and monitored on a monthly basis. The daily maximum
limit shall be equal to the standard for that parameter multiplied by the dilution of the receiving stream
under summer 7Q 10 conditions for non-carcinogens. Average flow should be used for carcinogens and
30Q2 flow should be used for aesthetic standards.
If a facility monitors semi-annually (twice/year), 10 data points would be obtained over a five-year permit
period which is slightly more than the minimum number of data points which will accurately characterize
an effluent discharge (USEPA March 1991).
In cases where a facility requests reconsideration of a limit requirement, monthly monitoring should be
required for at least 10 months so that 10 data points can be obtained and a second reasonable potential
calculation can be conducted. If there is no reasonable potential for a water quality violation, monitoring
should be reduced (to semi-annually).
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Permit Requirements for Dischar;&es fr,�m Oil & Petroleum Storage Facilities
C. _Turbidity'Monitoring (Paw Creek terminals)
Monitor quarterly..
(Monthly monitoring and limit of 50 NTU if facility demonstrates reasonable potential)
Based on concerns regarding anti-backsliding, the EPA requested the Division re-examine the basis for the
elimination of turbidity monitoring for 12 of the 14 Paw Creek oil terminals that were required to monitor
for turbidity prior to the most recent permit renewal. This second examination of the data showed that
there were turbidity standard violations since the last analysis at several of the oil terminals. The Division
therefore acknowledges that its second evaluation resulted in a different outcome from the initial
investigation and agrees that turbidity monitoring should be added to the discharge permits for the oil
terminals in Paw Creek. Facilities were sent notice in February 1999 that quarterly turbidity monitoring
would be required at the facility effective March 1, 1999. If sufficient data exist, then reasonable
potential should be performed to assess the need for more frequent monitoring and a limit of 50
NTU. For all facilities, the following footnote will be placed on the effluent limits page:
*Turbidity—Effluent shall not cause receiving stream turbidity to exceed 50 NTU. If receiving stream
background turbidity exceeds 50 NTU, effluent shall not cause this background value to increase.
III. Additional Monitoring Requirements for Water Supply (WS) Waters
A. Phenol
Monitor monthly
(Limit assigned if reasonable potential is demonstrated)
Phenol is a common component of petroleum compounds stored in terminals, can result in tainting of fish
tissue, and can cause taste and odor (organoleptic) problems in drinking water. In addition, phenol
discharged from terminals could combine with chlorine in water treatment facilities to form chlorinated
phenols. Limiting the discharge of phenol into water supply classified waterbodies could reduce
chlorinated phenol formation and their concentration in drinking water. As a result of the expected
occurrence of phenol in oil terminal facility discharges and the possibility of chlorinated phenol formation,
phenol will be monitored on a monthly basis in water supply classified waters.
Based on an extensive review and analysis of data collected during the last permitting cycle, the facilities
are no longer required to monitor for chlorinated phenols, since none were ever detected in oil terminal
effluent. The concern over limiting phenols lies in the need to inhibit formation of chlorinated phenolic
compounds at downstream water treatment plants. Joe Corporon of the NPDES Unit calculated an
allowable phenolic loading for each terminal in Mecklenburg County that will prevent a downstream
violation of the NC State standard for phenols of 1 µg/L. Meg Kerr wrote a similar memo for those
terminals in Guilford County in 1983. Reasonable potential will be performed using these allowable
phenolic loadings (see attached memo).
B. ' Benzene _ -"
Monitor monthly
Daily maximum limit - 1.19 ug/l * dilution of the receiving stream under average flow conditions
Benzene is a known carcinogen and can pose a potential health risk to humans consuming water with
benzene. The water quality standard for benzene in waters classified as water supplies is 1.19 µg/l. The
daily maximum limit for these facilities is therefore 1.19 multiplied by the dilution of the receiving stream
under average flow conditions (rounded to two significant digits). This limit may be excluded from the
permit only if there are sufficient data (eight sampling events) to demonstrate "no reasonable potential." If
there is no reasonable potential, there will only be a monthly monitoring requirement.
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Permit Requirements for Dischaeges from Oil & Petroleum Storage Facilities
C. MTBE
Monitor monthly_ _
MTBE special`condition".
Given that thiscompound is considered a possible carcinogen, there should be a greater effort to keep high
levels of MTBE out of water supply waters.: As per the Paw Creek Hearing Officer's Report, after one year of
monthly MTBE samples have been recorded, the facility must review the MTBE data. If no MTBE has been
detected in the effluent samples, the facility may request a minor modification to the permit reducing the
frequency of MTBE monitoring. If, however, MTBE has been detected during any of the discharge events,
the Permittee must develop a plan of action to reduce the levels of MTBE entering the receiving stream.
It is anticipated that an MTBE criterion for surface waters will be established at the time of the next permit
renewal. At that time, sufficient data will be available to assess the reasonable potential for a facility to
exceed any such standard or criterion.
REFERENCES
Dodson, Roy D., January 1996. Computing peak Flow: Which Method Is Most Rational?. Civil Engineering
News.
Kelling, Ray, (Division of Water Quality Chemistry Lab). June 1996. Conversations with P. Clark.
Kelling, Ray, (Division of Water Quality Chemistry Lab). February 2001. Conversations with N. Sierra.
Linville, Ron, (Winston-Salem Regional Office). March 1996. Telephone conversation with P. Clark.
Reid, Dianne, (Division of Water Quality - Planning Branch). June 1996. Conversations with P. Clark.
Shiver, Rick, (Wilmington Regional Office). July 2001. Findings and Recommendations for Public Hearing
Held on April 19, 2001.
USEPA. March 1991. Technical Support Document For Water Quality-Based Toxics Control. EPA/505/2-
90-001.
Page 8 of 8
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REAS3NABLE POTENTIAL ANALYSIS-AMENDED
Prepared by: Teresa Rodriguez
Facility Name= ExxonMobi I I Outfall 002 Parameter= Toluene Parameter= Chloroform
NPDES#= NC0004639 Standard= 11 ugA Standard= 5.7 ugA
Ow(MGD)= 0.456 Dataset= Dataset= DMR97-00
Qw(cfs)= 0.705987
701Os(cts)= 0 Modified Data Nondetects RESULTS Modified Data Nondetects RESULTS
1WC{55)= 100DO 0.5<1 Std Dev. 0.335 0.5<1 Std Dev. 0.091
0.5<1 Mean 0.551 0.5<1 Mean 0.514
Chronic CCC w/s7010 dil. Acute CMC wino dil. Frequency of Detection 0.5<1 C.V. 0.609 0.5<1 C.V. 0.178
Parameter FINAL RESULTS,ugtl FINAL RESULTS,u9A #Sam les #Detects 0.5<1 Sample# 43.000 0.5<1 Sample# 43.000
Toluene 0.5<1 0.5<1
Max.Pred Cw 4.9 0.5<1 Mutt Factor= 1.80 0.5<1 Mutt Factor
Allowable Cw 11.0 43 1 0.5<1 Max.Value 2.70 ugA 0.5<1 Max.Value 1.100 ugn
Chloroform 0.5<1 Max, Pred Cw 4.86 ugA 0.5<1 Max.Pred Cw 1.210 ugll
Max.Pied Cw 1.2 0.5<1 Allowable Cw 11.00 ugn 0.5<1 Allowable Cw 5.700 vgn
Allowable Cw 5.7 43 1 0.5<1 0.5<1
1,2 Dichloroethane 0.5<1 0.5<1
Max.Pred Cw 0.0 0.5<1 0.5<1
Allowable Cw 0.38 24 0 0.5<1 0.5<1
Benzene 0.5<1 0.5<1
Max.Pred Cw 0.0 0.5<1 0.5<1
Allowable Cw 1.2 45 1 0.5<1 0.5<1
Phenol 0.5<1 0.5<1
Max.Pred Cw 0.0 0.5<1 0.5<1
Allowable Cw 3437 45 0 0.5<1 0.5<1
2.7 1.1
Modified Data:Use 0.5 Detection Limit for non-detects 0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.6<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<t
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1
0.5<1 0.5<1

1.2 Dichloroethane Parameter= lBenzene Parameter= Phenol
0.38 vo Standard= 1.19 ugA Standard= 3437 ugA
Dataset= Dataset=
Modified Data Nondetects RESULTS ModifiedData Nondetects RESULTS ModifiedData Nondetects RESULTS
0.15<.3 Sid Dev. 4.91 E-09 0.5<1 Sid Dev. 0.075 5<10 Sid Dev. 0.000
0.15 c3 Mean 0.15 0.5<1 Mean 0.511 5<10 Mean 5.000
0.15<.3 C.V. 3.28E-08 0.5<1 C.V. 0.146 5<10 C.V. 0.000
0.15<.3 Sample# 24 0.5<1 Sample# 45.000 5<10 Sample# 45.000
0.15<.3 0.5<1 5<10
0.15<.3 0.5<1 MultFactor= 1.10 5<10 Mutt Factor=
0.15<.3 Mult Factor 0.5<1 Max.Value 1.00 5<10 Max.Value 5.000 ugA
0.15<.3 Max.Value 0.15 uy 0.5<1 Max.Pred Cw 1.10 5<10 Max.Pred Cw 0.000 ugA
0.15<.3 Max.Pred Cw 0 ugl 0.5<1 Allowable Cw 1 A 9 5<10 Allowable Cw 3437 ugA
0.15<.3 Allowable Cw 0.38 a 0.5<1 5<10
0.15<.3 0.5<1 5<10
0.15<.3 0.5<1 5<10
0.15<.3 0.5<1 5<10
0.15<.3 0.5<1 5<10
0.15<.3 0.5<1 5<10
0.15<.3 1 5<10
0.15<.3 0.5<1 5<10
0.15<.3 0.5<1 5<10
0.15c3 0.5<1 5<10
0.15 <.3 0.5<1 5<10
0.15 <.3 0.5<1 5<10
0.15<.3 0.5<1 5<10
0.15<.3 0.5<1 5<10
0.15<.3 0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10
0.5<1 5<10

REASONABLE POTENTIAL ANALYSIS
Prepared by: Teresa Rodriguez 318101
Facility Name= ExxonMobil I Outfall 002 Gar i��i�Uf u1
NPDES #= NC0004839 U
Ow(MGD) - 0.456
Ow(cfs) = 0.705987
70 10s{cfs)= 0
/WC(%) 100.00
Chronic CCC w/s7Q10 dil. Acute CIVIC wlno dil. Frequency of Detection
Parameter FINAL RESULTS, ugA FINAL RESULTS, ugfl #Samples # Detects
Toluene
Max. Pred Cw 4.9
Allowable Cw 11.0 43 1
Chloroform
Max. Pred Cw 1.2
Allowable.Cw 5.7 43 1
Benzene
Max. Pred Cw 0.0
Allowable Cw 1.2 0 0
Phenol
Max. Pred Cw 0.0
Allowable Cw 1.0 0 0
MTBE
Max. Pred Cw 963.5
Allowable Cw 11.6 45 26

Parameter= Toluene Parameter= Chloroform Parameter= IMTBE
Standard= 1 11 ug/I Standard= 5.7 ug/I Standard= 11.6 ug/I
Datasot= Daiaset= DMR97-00 Dataset=
Modified Data Nondetects RESULTS Modified Data Nondetects RESULTS ModifiedData Nondetects RESULTS
0.5 <1 Sid Dev. 0.335 0.5 <1 Sid Dev. 0.091 0.5I<1 ISid Dev. 43.153
0.5 <1 Mean 0.551 0.5 <1 Mean 0.514 0.5 <1 Mean 18.118
0.5 <1 C.V. 0.609 0.5 <1 C.V. 0.178 0.5 <1 C.V. 2.382
0.5 <1 Sample# 43.000 0.5 <1 Sample# 43.000 0.5 <1 Sample# 45.000
0.5 <1 0.5 <1 53 <1
0.5 <1 Mutt'Factor= 1.800 0.5 <1 Mult Factor= 1.100 0.5 Mult Factor F 4.100
0.5 <1 Max. Value 2.700 ug/l 0.5 <1 Max. Value 1.100 ug/I 95 Max. Value 235.000 ugll
0.5 <1 Max. Pred Cw 4.860 ugli 0.5 <1 Max. Pred Cw 1.210 ug/I 26.5 Max. Pred Cw 963.500 ugll
0.5 <1 Allowable Cw 11.000 "g/l 0.5 <1 Allowable Cw 5.700 ugll 134 Allowable Cw 11.600 ug/I
0.5 <1 0.5 <1 0.5
0.5 <1 0.5 <1 3.8
0.5 <1 0.5 <1 6.4
0.5 <1 0.5 <1 2.3
0.5 <1 0.5 <1 4.1
0.5 <1 0.5 <1 21.2
0.5 <1 0.5 <1 74
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 3.5
0.5 <1 0.5 <1 0.5 <1
2.7 1.1 0.5 <1
0.5 <1 0.5 <1 1.2
0.5 <1 0.5 <1 3.4
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 5.5
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 1.2
0.5 <1 0.5 <1 16
0.5 <1 0.5 <1 2
0.5 <1 0.5 <1 16.8
0.5 <1 0.5 <1 51
0.5 <1 0.5 <1 3.8
0.5 <1 0.5 <1 1.2
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 0.5 <1
0.5 <1 0.5 <1 42
0.5 <1 0.5 <1 235
0.5 <1 0.5 <1 1.2
0.5 <1
1.2

I NCO004839 l ExxonMobil CDutfell-602
Mecklenburg county
Date Flow TSS 0 & G Benzene Toluene Ethylben Xyiene 1,2 DCA Chloro# Phenol MTBE Fluorene Phenanth Turbidity
(MGD) (mg/L) (mg/L) (ug/L) (ug/L) (ug/L) (ug/L) (ug/L) (ug/L) (ug/L) (ug/L) (ug/L) (ug/L)
Jan-97 no disch
Feb-97 no disch
Mar-97 no disch
Apr-97 no disch
May-97 0.0007 <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
0,001 2.9 <1 <1 <1 <1 <1 <3 <1 <10 <1 <10 <10
Jun-97 0.007 <1 <1 <i <1 <1 <1 <.3 <1 <10 <1 <10 <10
Jul-97 0.0007 <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Aug-97 0.011 <1 <1 <1 <1 <1 <1 <.3 <1 <10 53 <10 <10
Sep-97 0.013 <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Oct-97 0.008 <1 <1 <1 <1 <1 <1 <.3 <1 <10 95 <10 <10
Nov-97 0.004 <1 <1 <1 <1 <1 <1 <.3 <1 <10 26.5 <10 <10
Dec-97 0.005 3.2 <1 <1 <1 <1 <1 2.7 1.1 <10 134 <10 <10
Jan-98 0.006 <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Feb-98 0.0005 <1 <1 <1 <1 <1 <1 <.3 <1 <10 3.8 <10 <10
Mar-98 0.014 <1 <1 <1 <1 <1 <1 <.3 <1 <10 6.4 <10 <10
Apr-98 0.011 <1 <1 <1 <1 <1 <1 <.3 <1 <10 2.3 <10 <10
May-98 0.01 <1 <1 <1 <1 <1 <1 <.3 <1 <10 4.1 <10 <10
Jun-98 0.01 2.8 <1 <1 <1 <1 <1 <.3 <1 <10 21.2 <10 <10
Jul-98 0.009 <1 <1 1 1 <1 <1 <.3 <1 <10 74 <10 <10
Aug-98 0.008 4.6 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Sep-98 0.008 1.1 <1 <1 <1 <1 <1 <.3 <1 <10 3.5 <10 <10
Oct-98 0.008 1.7 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Nov-98 0.008 2.1 <1 <1 2.7 <1 <1 <.3 <1 <10 <1 <10 <10
Dec-98 0.008 9.4 <1 <1 <1 <1 <1 <.3 <1 <10 1.2 <10 <10
Jan-99 0.009 <1 1.5 <1 <1 <1 <1 <.3 <1 <10 3.4 <10 <10
Feb-99 0.009 1.3 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Mar-99 0.014 2.6 1.2 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Apr-99 0.008 2.2 <1 <1 <1 <1 <1 <.3 <1 <10 5.5 <10 <10
May-99 0.009 2.8 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Jun-99 0.008 2.2 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10 2.1
Jul-99 0.01 <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Aug-99 no disch <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Sep-99 0.0006 <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10 1.8
Oct-99 0.009 <1 <1 <1 <1 <1 <1 <.3 <1 <10 1.2 <10 <10 2.3
Nov-99 0.008 4 4.2 <1 <1 <1 <1 <.3 <1 <10 16 <10 <10
Dec-99 0.008 8.8 <1 <1 <1 <1 <1 <.3 <1 <10 2 <10 <10 2
Jan-00 0.014 <1 <1 <1 <1 <1 <1 <.3 <1 <10 16.8 <10 <10
Feb-00 0.015 2 <1 <1 <1 <1 <1 <.3 <1 <10 51 <10 <10
Mar-00 0.013 <1 <1 <1 <1 <1 <1 <.3 <1 <10 3.8 <10 <10
Apr-00 0.008 2.4 <1 <1 <1 <1 <1 <.3 <1 <10 1.2 <10 <10
May-00 no disch <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Jun-00 0.009 <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10 2.3
Jul-00 0.0029 <1 <1 <1 <1 <1 <1 <3 <1 <10 <1 <10 <10
Aug-00 0.0009 <1 <1 <1 <1 <1 <1 <.3 <1 <10 42 <10 <10

Sep-00 0.0093 <1 <1 <1 <1 <1 <1 <.3 <1 <10 235 <10 <10
Oct-00 0.009 <1 <1 <1 <1 <1 <1 <.3 <1 <10 1.2 <10 <10 2.3
Nov-00 0.0073 <1 <1 <1 <1 <1 <1 <.3 <1 <10 <1 <10 <10
Dec-00 0.0057 <1 <1 <1 <1 <1 <1 <.3 <1 <10 1.2 <10 <10
SUMMARY
TSS O & G Benzene Toluene Ethylben Xylene 1,2 DCA Chlorof Phenol MTBE Fluorene Phenanth Turbidity
m /L m /L u /L u /L u /L u IL u /L u /L u /L u /L u /L u /L
Max 9.4 4.2 1 2.7 2.7 1.1 235 2.3
Ave 3.3 2.3 1 1.85 2.7 1.1 32.212 2.133333
num samples 45 45 45 45 45 45 45 45 45 45 45 45 6
detected j 17 31 11 2 C)l 01 11 11 01 251 01 01 6

REASONABLE POTENTIAL ANALYSIS-AMENDED
Prepared by: Teresa Rodriguez
Facility Name= ExxonMobiVOutfall 001
NPDES#= NC0004839
Ow(MGD)= 0,456
Ow(cfs)= 0.705987
701Os(cfs)= 0
/WC(%)= 100.00
Chronic CCG w/s7Q10 dil. Acute CMC wlno dil. Frequency of Detection
Parameter FINAL RESULTS,ugfl FINAL RESULTS, ugfl #Samples #Detects
Xylene
Max. Pred Cw 30.2
Allowable Cw 88.5 3 1
Benzene
Max, Prod Cw 0.0
Allowable Cw 1.19 15 0
Phonol
Max. Prod Cw 0.2
Allowable Cw 140.0 15 2
Modified Data: Use 0.5 Detection Limit for non-detects

Parameter= jXylene I Parameter= Benzene Parameter= Phenol
Standard= 88.5 ugll Standard= 1.19 UgIl Standard= 140 ugll
Dataset= DMR97-00 Dataset= DMR97-00 Dataset= DMR97-00
Modified Data Nondetects RESULTS Date ModifiedData Nondetects RESULTS ModifiedData Nondetects RESULTS
0.5 <1 Std Dev, 1.852 Sep-99 2.5 <5 Std Dev. 0.516 0.025 <.05 Std Dev. 0.019
4.2 Mean 2.400 Oct-99 0.5 <1 Mean 0.633 0.025 <.05 Mean 0,032
2.5 <5 C.V. 0.772 Nov-99 0.5 <1 C.V. 0.815 0.025 <.05 C.V. 0.601
Sample# 3,000 Dec-99 0.5 <1 Sample# 15.000 0.025 <.05 Sample# 15.000
Jan-00 0.5 <1 0.025 <.05
Mutt Factor= Feb-00 0.5 <1 Mutt Factor= 0.025 <.05 Mutt Factor
Max.Value 4.200 ugll Mar-00 0.5 <1 Max. Value 2.500 ugll 0.025 c05 Max.Value 0,090 Pg/l
Max. Pred Cw 0.000,rgll Apr-00 0.5 <1 Max. Pred Cw 0.000 ug/l 0.025 <,05 Max. Pred Cw 0.234 ug/l
Allowable Cw 88.500 ugll May-00 0,5 <1 Allowable Cw 1.190 ugll 0.025 <.05 Allowable Cw 140.000,ugll
Jun-00 0.5 <1 0.09 0.09
Jul-00 0.5 <1 0.025 <.05
Aug-00 0.5 <1 0.067 0.067
Sep-00 0.5 <1 0.025 <.05
Nov-00 0.5 <1 0.025 <,05
Dec-00 0.5 <1 0.025 c05

REASONABLE POTENTIAL ANALYSIS
Prepared by: Teresa Rodrigg�uez��3/8/01
Facility Name= Exxon -OOZ '
NADFS#=I NC0004839 /
Qw(MGD)= 0.456
Qw(cfs)= 0.705987
701 0s(cfs,= 0
iWC(%)= 100.00
Chronic CCC w/s7Q10 dil. Acute CIVIC w/no dil. Frequency of Detection
Parameter FINAL RESULTS, ug/1 FINAL RESULTS, u /I #Samples # Detects
Toluene
Max. Pred Cw 0.0
Allowable Cw 11.0 0 0
Xylene
Max. Pred Cw 2916.1
Allowable Cw 88.5 9 0
Benzene
Max. Pred Cw 1569.6
Allowable Cw 1.2 44 0
Phenol
Max. Pred Cw 44.8
Allowable Cw 1.0 39 0
MTBE
Max. Pred Cw 0.0
Allowable Cw 11.6 0 0

Parameter= IXylene I Parameter jBenzene Parameter Phenol
Standard= 88.5 ugll Standard= Ii.19 ugll Standard= 1 11 ugll
Dataset= DMR97-00 Dataset= Datasel=
Modified Data Nondetects RESULTS ModifiedData Nondetects RESULTS ModifiedData Nondetects RESULTS
0.5 <.01 Std Dev. 82.575 0.05 <c1 Sid Dev. 62.597 0.5 <1 Std Dev. 1.118
110 110 Mean 44.911 0.05 <.1 Mean 20.219 0.5 <1 Mean 0.269
0.5 <1 C.V. 1.839 0.05 <.1 C.V. 3.096 0.5 <1 C.V. 4.150
0.5 <1 Sample# 9.000 2 2 Sample# 44.000 0.5 <1 Sample# 39.000
241 241 50 50 0.025 <.05
50.2 50.2 Mult Factor= 12.100 15 15 Mult Factor= 4.8001 0.025 <.05 Mult Factor F 6.400
0.5 <1 Max. Value 241.000 ug/l 0.003 0.003 Max. Value 327.000 ugll 0.081 0.081 Max. Value 7.000 ug/l
0.5 <1 Max. Pred Cw 2916.100 ugll 327 327 Max. Pred Cw 1569.600 ugll 0.025 <.05 Max. Pred Cw T 4:800 ugll
0.5 <1 Allowable Cw 88.500 ugll 32.2 32.2 Allowable Cw 1.190 ugll 0.025 <.05 Allowable Cw 1.000 ugll
8.4 8.4 0.025 <.05
101 101 0.025 <.05
250 250 0.025 <.05
36 36 0.025 <.05
40.8 40.8 0.025 <.05
0.5 <1 0.025 <.05
3.6 3.6 0.025 <.05
4 4 0.025 <.05
1.5 1.5 0.025 <.05
2.1 2.1 0.025 <.05
0.5 <1 0.025 <.05
1.9 1.9 0.025 <.05
1.4 1 A 0.025 <.05
0.5 <1 0.025 <.05
0.5 <1 0.025 <.05
0.0005 <.001 0.025 <.05
1.6 1.6 0.025 <.05
0.5 <1 0.5 <1
0.5 <1 7 7
0.5 <1 0.1 0.1
0.5 <5 0.025 <.05
0.5 <1 0.025 <.05
0.5 <1 0.025 <.05
0.5 <1 0.025 <.05
0.5 <1 0.029 0.09
0.5 <1 0.067 0.067
0.5 <1 0.025 <.05
0.5 <1 0.025 <.05
0.5 <1 0.025 <.05
0.5 <1 0.025 <.05
0.5 <1
0.5 <1
0.5 <1
0.5 <1
0.5 <1

Parameter= MTBE
Standard= I 11.6 ugll
Dataset=
ModifiedData Nondetects.RESULTS
Std Dev. #DIV/Q!
Mean #DIV/0!
C.V. #DIV/0!
Sample# 0.000
Mult Factor= 6.300
Max. Value 0.000 ug/I
Max. Pred Cw 0.000 ug/I
Allowable Cw 11.600 ug/I

NC0004839 ExxonMobilQ��tfa QOt�
Mecklenburg county
Date Flow O& G Phenol Benzene TSS Xylene Tox EPA 624/625
(MGD) (mg/L) (mg/L) (ug/L) (mg/L) (ug/L) (ug/L) Turbidity
Jan-97 0.0438 <.5 <1 <.01 4
0.0438
0.1579
0.0452
0.0141
0.055
❑.0161
0.0513
Feb-97 0.0451 <1 <1 <.01 5
0.055
0.0317
0.04
0.059
Mar-97 0.0099 <.5 <1 <.01 4 <.01 P
0.062
0.019
0.058
0.014
Apr-97 0.0214 <.5 <1 2 4
0.057
0.0498
0.0468
0.0554
0.0777
0.0816
May-97 0.0143 <.5 <1 >50 4 110
0.0635
0.0657
0.0667
0.019
0.055
0.014
Jun-97 0.0353 <1 <.05 15 3.6
0.1052
0.0822
0.0102
0.0353
0.0533
0.072
0.029
Jul-97 0.1038 <1 <.05 0.003 3.7
0.053
0.0642
0.048
0.102
0.106
0.1126
0.2095
Aug-97 0.0053 <1 0.081 327 5.8
0.0426
Sep-97 0.1097 <1 <.05 32.2 2.1
0.0097
0.1567
0.0539
0.0015
Oct-97 0.1034 3.7 <.05 8.4 2.9
0.0047
0.0436
0.0643
0.1791

98L0'o
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0.008
0.0353
0.0016
Nov-98 0.0807 <1 <.05 <1 3.2
0.023
0.0024
0.1046
Dec-98 0.0731 1.9 <.05 1.9 2.7
Jan-99 0.0438 <1 <.05 1.4 1
0.003
0.1327
Feb-99 0.0848 <1 <.05 <1 3.1
0.0033
0.0555
0.0624
0.0041
Mar-99 0.0473 2.7 <.05 <1 2 <1 p non detect 5.05
0.0056
0.0214
0.0016
0.0035
0.033
Apr-99 0.0153 <1 <.05 <.001 2.3
0.0746
0.0823
0.0816
May-99 0.0573 <1 <.05 1.6 4.4
0.0019
0.0019
0.105
0.0485
Jun-99 0.051 <1 <05 <1 5.2 3.4
O.OD37
0.093
0.0564
0.0473
0.0834
Jul-99 0.0496 <1 <.05 <1 <4
0.0315
0.0111
0.0059
0.0931
Aug-99 0.0805 <1 <.05 <1 2
Sep-99 0.0833 <.8 <.05 <5 2 <1 no detect
0.0023
0.1834
0.004
Oct-99 0.1473 <1 <.05 <1 <2
0.0875
0.12
0.1346
0.0642
0.0385
Nov-99 0.0221 <1 <.05 <1 3
0.055
0.0252
Dec-99 0.0184 <1 <.05 <1 2.4
0.083
Jan-00 0.0828 <1 <.05 <1 14
0.0551
0.0541
0.1563
0.0016
Feb-00 0.067 <1 <.05 <1 6.2

u
0.0993
Marr00 0.0224 2.7 <.05 <1 16.8 4.2 P no detect 28
0.0078
0.2464
0.161
0.0692
Apr-00 0.0015 <1 <,05 <1 2
0.0485
0.1043
0.1167
0.0081
May-00 0.0318 <1 <.05 <1 21
0.0379
Jun-00 0.0543 <1 0.09 <1 6.4 5.1
0.0652 12.3
0.091
0.0027
Jul-00 0.1331 <1 <.05 <1 4.4
0.146
0.1474
O.O 146
Aug-00 0.1101 <1 0.067 <1 4.2
0.0492
0.062
0.0001
0.0198
Sep-00 0.0622 <1 <.05 <1 <2 <5 P no detect
0.1312
0.0394
0.3464
Oct-00 no disch
Nov-00 0.0369 <1 <.05 <1 2.6 2.6
Dec-00 0.0996 1.1 <.05 <1 1 3.41 1 1 8.6
SUMMARY
Flow 4&G Phenol Benzene TSS Xylene Tox EPA 624/625
MGD m IL m IL u /L) m /L u /L u /L Turbidity
Ave 0.060072 2.42 1.23133 48.7355 4.9262 101.35 9.29286
Max 0.3464 3.7 7 327 26 241 28
#samples 40 41 45 46 9 5 4 7
#detects 51 421 41 1 7

DENR/DWQ
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NCO04839
Facility Information
Applicant/Facility Name! ExxonMobil Refining & Supply Co./Charlotte Terminal
Applicant Address: P.O. Box 82. Charlotte, NC 28130
Facility Address: 6801 Freedom Drive, Paw Creek, N.C.
Permitted Flow Outfall 001 is not limited
Outfall 002 is limited to 0.864 MGD per discharge
Type of Waste: Stromwater from diked areas, groundwater remediation and stormwater
from the loading racks areas
Facility/Permit Status: Active; Renewal
County: Mecklenburg
Miscellaneous
Receiving Stream: UT to Long Regional Office: Mooresville
Creek
Stream Classification: WS-IV State Grid /USGS Quad, FISSW (Mt. Island
Lake)
303(d) Listed? No Permit Writer: Teresa Rodriguez
Subbasin: 03-08-34 Date: 3/9/01
Drainage Area (mi2): 0.01
Summer 7Q10 (cfs) 0 A. _.4
Winter 7Q 10 (cfs): 0 ` +
30Q2 (cfs) 0
Average Flow (cfs): 0
IWC(%): 100%
Lat. 350 16' 40"N Lon $0°SG' 27"W
BACKGROUND
This facility changed name from Exxon Company USA to ExxonMobil Refining and Supply
Company. They have two outfalls:
Outfall 001 - discharges stormwater from the storage tanks dikes and treated stormwater and washwater from
the containment pads and loading racks area. The treatment system consists of an oil water separator, a holding
pond and a GAC unit.
Outfall 002 -discharges treated groundwater. The treatment system consists of an oil water separator, an air
stripper, and a carbon polishing unit.
FILE REVIEW
Correspondence
The Mecklenburg County Department of Environmental Protection (MCDEP) has performed 5
inspections since 1996. The facility received a notice of violation in April 2000 regarding the method used for
flow measurement.
DMR Review:
Outfall 001 - DMRs were reviewed for the period of January 1997 to December 2000. The mean flow
was 0.0614 MGD. The maximum flow (used below in the reasonable potential calculations) was 0�4, 563
MGD. Total suspended solids during this time averaged 5 mg/L for all the values above quantitation level, the
maximum value was 29 mg/L. Oil and Grease was detected five times, the maximum was 3.7 mg/l. Phenol was
detected five times with a maximum of 7 pg/L. Benzene was detected 18 timds with a maximum value of 327
µg/l. Xylene was detected 4 times with a maximum of 241 jig/I. The facility passed 5 of 5 acute toxicity test.
They performed EPA Method 624/625 four times and no parameters, other than the above mentioned, were
detected.
Fact Shect
NPDES NCO046992
Renewal
Page l

Outfall 002 - DMRs were reviewed for the period of January 1997 to December 2000. The mean flow
was 0.0079 MGD. The maximum flow (used below in the reasonable potential calculations) was 0.014 MGD.
Total suspended solids during this time averaged 3.3 mg/L for all-the values above quantitation level, the
maximum value was 9.4 mg/L. Oil and Grease was detected three times, the maximum value was 4.2 mg/L.
Phenol was below quantitation level for all samples. MTBE was detected 24 times with a maximum of 235
µg/L. Benzene, ethylbenzene, xylene, fluorene and phenantharene were always below quantitation level.
Toluene was detected once at 2.7 ftgll. Chloroform and 1,2 Dichloroethane were detected once each at 1.1 ftgll
and 2.7 ttg/l respectively.
Reasonable Potential Analysis:
Outfall 001 — Reasonable potential was done for xylene and benzene and both showed reasonable
potential to exceed water quality standards. The maximum predicted concentration for xylene was 29 t6 pg/l,
the allowable concentration is 88 feg/l. The maximum predicted concentration for benzene was 1569 pg/1, the
allowable concentration is 1.2 fig/l.
Outfall 002 — Reasonable potential was done for MTBE, chloroform and toluene. MTBE presented a
reasonable potential to exceed water quality standards. The maximum predicted concentration for MTBE was
963 AgIL, the allowable concentration is 11.6 ltg/L. Chloroform and toluene did not show reasonable potential.
PERMITTING STRATEGY
The permitting strategy for this and all oil terminals in the state is based upon a 2001 NPDES docu vent
entitled, "Permit Requirements for Discharges from Oil and Petroleum Storage Facilities." This document is
based upon a 1996 SOP and has been updated after a data review and internal discussions. It delineates
monitoring frequencies and permitting limits for contaminants commonly found at these sites. Below, it is
referred to as the "2001 SOP."
Waste Load Allocation (WLA)
The last waste load allocation was performed in 1993.
Oil Terminal SOP:
For Outfall 001 the flow, toxicity, TSS and oil and grease requirements specified in the previous
permit and the 2001 SOP (Parts I.A. — I.D.) remain unchanged. Since the facility did not detect additional
parameters in EPA Method 624/625, it was eliminated A daily maximum limit of 0.11 m /p�L was included for
phenol based on the allocation for the Paw Creek area. The limit for phenol was calculated using the maximum
flow discharged for the evaluation period (0._4 MGD) and the allocation of 0.43 lbs/day for each-discharger.
The requirements in Part I F of the 2001 SOP of monitoring or naphtalene was incorporated into the permit. A
limit for MITE was added as per Part 11LC of the 2001 SOP. Limits were added for benzene and xylene based
on the reasonable potential analysis. Addition of monitoring for ethylbenzene and toluene were added as part
of the BTEX monitoring requirement in Part I.E. of 2001 SOP. As per Parts I.G. and I.H. of the 2001 SOP,
there can be no direct discharge of tanks solids, tank bottom water or the rag layer, and no direct discharge of
hydrostatic test water if concentrations of benzene and/or toluene exceed the water quality standard. Part B.C.
lists a requirement specific to the Paw Creek terminals — quarterly turbidity monitoring as mandated by the
EPA.
The requirements for Outfall 002 are for groundwater remediation systems and follow the requiremtns
in the general permit to discharge petroleoum contaminated groundwater and similar wastewaters. The flow,
TSS, oil and grease, ethylbenzene, xylene, naphtalene, t,2 dichloroethane, iron and manganese requirements
specified in the previous permit remain unchanged. A daily maximum limit of 3 mg/L was included for phenol
based on the allocation for the Paw Creek area. The limit for phenol was calculated using the maximum flow
discharged for the evaluation period (0.014 MGD) and the allocation of 0.43 lbs/day for each discharger. The
limits for toluene, chloroform and be were eliminated since they do not present reasonable potential to
exceed water quality standards. A limit was added for MTBE since this parameter presented reasonable
potential to exceed the water quality standard. Quarterly turbidity monitoring is required by EPA for all Paw
Creek terminals.
SUMMARY OF PROPOSED CHANGES
Outfall 001
• Addition of MTBE limit
• Addition of phenol limit
Pact Sheet
NPDES NCO046892
Renewal
Page 2

Addition of naphthalene monitoring
Addition of benzene and xylene limits
Addition of quarterly turbidity monitoring
Addition of Toluene and ethylbenzene monitoring
• Elimination of semi-annual monitoring for EPA Method 624/625
Outfall 002
• Addition of quarterly turbidity monitoring
• Addition of MTBE limit
• Addition of phenol limit
• Elimination of benzene, chloroform and toluene limits
PROPOSED SCHEDULE FOR PERMIT ISSUANCE
Draft Permit to Public Notice: March 14, 2001
Permit Scheduled to Issue: April 27, 2001
NPDES DIVISION CONTACT
If you have questions regarding any of the above information or on the attached permit, please contact Teresa
Rodriguez at [phone] ext. 595.
NAME: �PL` G�vl DATE:
REGIONAL OFFICE COMMENTS
NAME: DATE:
SUPERVISOR: DATE:
Fact Sheet
NPDES NCO046892
Renewal
Page 3

SOC PRIORITY PROJECT: Yes No X
To: Permits and Engineering Unit
Water Quality Section
Attention: Jeanette Powell
Date: April 20, 2001
NPDES STAFF REPORT AND RECOMMENDATION_ _
County: Mecklenburg [�Q i
MRO No.: 01-37 ; I
Permit No: NCO004839 u APR 2 5 2001 t
PART I - GENERAL INFORMATION DENR - WATER QUALITY
POINT SOURCE BRANCH
I. Facility and Address: ExxonMobil Refining& Supply Company
P.O. Box82
Charlotte, N.C. 28130
2. Date of Investigation: 04-03-01
3. Report Prepared By: Samar Bou-Ghazale, Env. Engineer I
4. Persons Contacted and Telephone Number: Mr. Robert Gaston, Terminal Superintendent;
Tel# [phone],
5. Directions to Site: Travel northwest from Charlotte on Highway 27 to the Community of
Thrift. The Exxon terminal is located on the left side of Highway 27 approximately 100
yards past the junction of Highway 27 and Old Mount Holly Road (S.R. 1619).
6. Discharge Point(s). List for all discharge points:
Latitude: 35` 16' 40" Longitude: 80' 56' 27"
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,N.C.
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 6%. The site
is not located in a flood plain.
9. Location of nearest dwelling: The nearest dwelling is approximately 250 feet from the site.
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 appeared to be headwaters of an unnamed tributary to Long Creek. The
stream flow was low at the time of inspection. There are several other discharges
from oil terminal facilities into the receiving stream.
PART Il - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
1. a. Volume of wastewater to be permitted: Stormwater discharge from the tank area is
intermittent depending on rainfall. Also, the discharge from the groundwater
remediation system is not limited.
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)? 0.057
MGD.
d. Date(s) and construction activities allowed by previous Authorizations to Construct
issued in the previous two years: N/A.
e. Please provide a description of existing or substantially constructed wastewater
treatment facilities: The existing wastewater treatment facilities for groundwater
remediation consist of an oil/water separator and an air stripper with a discharge at
outfall 002. The wastewater treatment facilities for the stormwater consist of a pond
and an oil/water separator which discharges at outfall 001. The pond receives runoff
water from the entire tank farm site and discharges through the oil/water separator.
The discharge from the loading/unloading area is also directed to the oil/water
separator. Both outfalls discharge to the creek from the same catch basin.
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.
NPDES Permit Staff Report
Page 2

h. Pretreatment Program (POTWs only): NIA.
2. Residuals handling and utilization/disposal scheme: Generation of residuals is not expected.
3. Treatment plant classification: Class 1
4. SIC Code(s): 5171
Primary: 39 Secondary: 73
Main Treatment Unit Code: 55000
PART III - OTHER PERTINENT INFORMATION
1. Is this facility being constructed with Construction Grant Funds or are any public monies
involved (municipals only)? NIA.
2. Special monitoring or limitations (including toxicity) requests: NIA
3. Important SOC, JOC or Compliance Schedule dates: (please indicate) NIA.
4. Air Quality and/or Groundwater concerns or hazardous waste utilized at this.facility that may
impact water quality, air quality or groundwater? Contaminated groundwater already
exists at the site. GW comments should be obtained. No hazardous materials will be
employed. Air quality permitting for the air stripper has been handled by Mecklenburg
County.
PART IV - EVALUATION AND RECOMMENDATIONS
ExxonMobil Refining & Supply Company is requesting an NPDES Permit renewal for the
discharge of treated groundwater and stormwater at the subject facility.
It is recommended that the NPDES permit be renewed.
1
Signature of Repoit.-lsreparer Date
Water Quay y Regional Supervisor Date
Page 3

ExxonMobil
Refining and Supply Company
4 Charlotte Terminal
P.O.Box 82
Charlotte,NC 28130
E�onMobil
Refining & Supply
May 2, 2001 —=�
Ms. Teresa Rodriguez z
NCDENR- DWQ-NPDES Unit o
1621 Mail Service Center C%M
j r•� CCW
Raleigh, NC 27699-1617 a
`•� 3.o
Re: Draft iNPDES Permit Q
ExxonMobil Charlotte Terminal
Permit #: NC0004839
Dear Ms. Rodriguez:
ExxonMobil is currently reviewing the proposed NPDI:S permit issued for its Charlotte, NC fuels
distribution terminal. We are also hereby requesting that you grant us an approximately thirty•(30) day
extension totour-original-comment_period:until-the'close of business-on May_25, 2001 to allow us to ?
complete_•and file-our comments. We believe that we are entitled to this extension in accordance with
State of North�Carolina-Regulation 15A NCAC 2I-1.0109(a), which provides that interested parties,
particularly the applicant, will have an opportunity to review the fact sheet during the comment period.
The-fact.sheet.-was-not provided with the-draft permit-nor was there_indication that a fact sheet was
available in the Department's public announcement of the notice and comment period. Based upon our
initial review, we believe that additional time is required to study and address several aspects of the draft
permit and the fact sheet before the permit is issued as a final document.
Although we reserve the right to make additional comments by May 25, are we offering the following
comments at this time for the Department's consideration. furthermore, we would be receptive to the
opportunity for additional dialogue with the Department concerning these issues, which arc summarized
below and explained in detail on the pages attached to this letter.
are concerned that the methodology employed by the Department to arrive at the proposed
fir' fi nitatIons, including the application of Water Quality-Based Effluent Limitations (WQBELs) to
stormwater-discharges, is not consistent with EPA guidance on the subject;
� 2 Theme hodology-emuloyed to classify'the'unnamed-tributary does-66t:account_f6r-dilution;_of_flows
during-storm-events, natural biodegradation,,and-att-Ci(i6tion--of.conceritiatiotns.-downstream, and the -
fact-that theMlinits�are;being-applied:at_the,et'fTuent..dischafge.p0inf:rathe- than the point whcre`-the
rstream will`be used as a source-ofdrrnkmg°wafer;
3. The basis for the-MTBE'limiiation is not consistent with that of the other water quality parameters
and its apparent adoption was not afforded technical review and comment by the potentially-
impacted public and industry;

Ms. Teresa Rodriguez
May 2, 2001
Page 2
4. �he-application_of performance=based limits does not accounf for the characteristics of_stormwater,
_including the variability of discharge flow rates, the-variability of concentrations, and the lack--of
ck--of
proven technology for stormwater treatment; and,
5. : Compliance schedules were not provided for any of the proposed limitations. —
Additionally, we wish to make specific comments pertaining to the proposed limitations and other
content in the permit that are also discussed in the'attachment to this letter.
I would welcome the opportunity to discuss our request with you and will contact you shortly. In
addition, please provide a written response to our request for an extension of our comment period.
Sincerely,
Steve D. Gif&, P.E.
Environmental Advisor
C: R.E. Gaston,Terminal Superintendent
Paul K. Cole, ExxonMobil Law Department

Ms. Teresa Rodriguez
May 2, 2001
Page 3
ATTACHMENT-EXPLANATION OF PERMIT COMMENTS
1. General Comments
a) Inclusion of Compliance Schedules in the Permit: We believe that the Department should provide
the discharger with an opportunity to meet a reasonably established compliance schedule in those
cases where the discharger can not reasonably meet the discharge limitations at the time of the
issuance of the permit. 40 CFR 122.47 provides in part that the permit may, when appropriate,
specify a compliance schedule leading to compliance with the Clean Water Act (CWA) and
applicable regulations. Furthermore, 15A NCAC 211.0112 (b)(2) provides that the Director of the
NCDENR is authorized to issue a permit containing time schedules for achieving compliance
with applicable effluent standards and limitations, water quality standards and other legally
applicable requirements. We believe compliance schedules"are-appropriate-for the_proposed�,
ibe`nzene;.xylene,CV1TBE, and:phenorlimits for-outfall-001_and-the—phenol,-MTBE-and_l,-2-)
dic�hlo_roethane.litnits_for-outfa11;002:1We would be prepared to discuss the specific provisions of
each compliance schedule with the Department;
b) Use--of-BMPs:rather�than-Effluent-L-imitations; According to the U.S. EPA, the=interim permitting
apprva_ch for_toxic-compounds-in-stotmwater_discharges--should_use.Best-ManagementzPractices
(BMP.$)zin_stormwater_permits,_and-expanded-or.:better-tailored_BMPs=in_subsequent=permits,
where necessary, to provide for the attainment of water quality standards! In cases where
adequate information exists to develop conditions that are more specific or limitations to meet
¢r' water quality standards, these conditions or limitations are to be incorporated into stormwater
permits, as necessary and appropriate. Such conditions or<limitations-may include-an-integrated
suite-_of-BMP.s,=performance-objecti.ves,_narrativerstandards,_monitoring-triggers,naction--levels,
and_others-, Generally, only after the long-term control plan is in place and after collection of
sufficient water quality data (including applicable wasteload allocations developed during a
TMDL process) should numeric water quality-based effluent limitations be included in the
permit. This would generally occur only after one or more permitting cycles. We believe this
approach, rather than the application of effluent limitations, is valid and most appropriate for the
Charlotte ierminal;
) '�Con`sideration of-Statistical-Variability-7 The drinking water criteria used for benzene, xylene,
MTBE, and phenol are based on an assumed exposure of 70 years. On a technical basis, it is not
k° appropriate to apply such criteria directly to an effluent as a daily maximum limit, or even as a
monthly average limit, EPA's Technical Support Document (TSD) for Water Quality-based
Toxics Controls provides statistical variability factors for calculating daily average and daily
maximum permit limits from long-term averages, such as the benzene criterion. For example, the
daily maximum factor is 3.11 (99 percentile),'which allows the transla[ion of a long-term average
water quality criterion to a daily maximum permit limit to include statistical variability (EPA's
TSD and permitting methodology emphasizes this). In the case of benzene, using the
' USEPA's "Interim Permitting Approach for Water Quality-Based Effluent Limitations in Storm Water Permits",
August 20, 1997, available at littp://www.epa.gov/owm/pipes/storni/misc/swpol.txt/.
2 U.S. EPA, Office of Water,March 1991.

Ms. Teresa Rodriguez
May 2, 2001
• Page 4
Department's proposed limit of 1.19 ug/L, the daily maximum benzene limit should be about 3.8
uglL even without the mixing zone allowance;
d) Limits based on Human Health Criteria: The proposed permit also applies human health-based
1/ criteria to effluent, without any allowance for dilution in the receiving water, However, the use
of a harmonic mean or similar dilution flow for applying human-health water quality criteria
(WQC) that are based on 70-year exposures is well documented and scientifically supported.
Additionally, for compounds that are not bioaccumulative (e.g., benzene, phenol, MTBE, and
ylene), it is not necessary for the WQC to be applied at a low flow condition. Rather, a dilution
/allowance using the harmonic mean stream flow is generally applied;
�e) Classification of Receiving Water and use of Mixing Zones: The discharge for the Charlotte
terminal is to an unnamed tributary, which is intermittent (associated with storm water). In this
situationjvis_not.appropriate to apply criteria that are based on drinking water supply.standards
to-an intermittent stream:--Rather;the"drinking water criterion should apply in-Long-Creek, which
has-a:base flow and may be:used'for a water supply, Stormwater flows into the tributary, which
will occur at a time not associated with the critical low-flow period, should also consider the,
dilution that will occur.. A mixing zone is therefore appropriate.. In addition, a dilution allowance
should be used based on the harmonic mean flow in Long Creek. By considering a mixing zone
that does not overlap the water supply intake, an effluent limit that takes attenuation and
degradation into account is therefore protective of the water supply;
f) Consideration of Upstream Flows in Wasteload Allocation: We understand that the Department
q performed a waste load allocation for phenol. While_the use:of-a_wdsteload-allocationj(WLA)
maybe an effective means-for protection-of--a drinking water supply (and should.possibly be
�1 considered for other compounds as well), the WLA should also take into account stream flow at
the-time-of discharge_ {Given that the 001 discharge is intermittent, and occurs associated with
storm events, the WLA should take into account stream flow at the time of discharge and
upstream flows in Long Creek. Variability factors should also be applied to the average waste
load allocations in calculation of permit criteria;
g) Documentation of Reasonable Potential: Permitting authorities are required to establish a basis
that a facility has the "reasonable potential" to cause or contribute to an excursion of numeric or
narrative water quality criterion prior to developing water quality-based effluent limitations
according to 40 CFR 122.44(d)(1)(1). We=believe=that-the-"reasonable-and-potential analysis"
(RPA)-conducted by-the-Department should hav"e-take-en .into,account the variability oft the
pollutant-and-dilution'in mixing zones as allowed in 40 CFR 122.44(d)(1)(ii). EPA's TSD3
outlines the factors that should be considered by the permit writer in a RPA.
2. Compound-specific Comments
a) Benzene limitation 001 : In 1998 and 1999, ExxonMobil (then Exxon Company, U.S.A.) entered
ll into discussions with the Department concerning exceedances of the in-stream benzene standard
�� at outfall 001. With the concurrence of the Department, Exxon proactively installed a carbon
filtration system with the understanding that the presence of a system to treat the discharges could
3"Technical Support Docunient for Water Quality-Based Toxics Control"(EPA/505/2-90-001,March 1991)

Ms. Teresa Rodriguez
May 2, 2001
Page 5
alleviate the need for a limitation in the present permit. Use of this system to treat contact water
prior to discharge was initiated in 1999. This approach is consistent with EPA's interim
permitting approach for toxic compounds in stormwater discharges, which uses BMPs, and
expanded or better-tailored BMPs in subsequent permits, where necessary, to provide for the
Rq 10 sva� attainment of water quality standards.4 Consistent with the approach to use BMPs to mitigate the
D d �� potential to exceed the water quality standard benzene should resently.be included in-the ermit
�c>tec�.��,z,-yL,,�gc� p q Y ,L-� �- P Y- _ p
as-a.monitoring:requirement.and not a limitation.__Based-on additional monitoring, a reasonable
and potential analysis (RPA) should be completed to_deterrnine if it-is necessary to,include limits
for benzene;in the,permit in the fufdre. At a minimum, the RPA should be based on the existing
monitoring conducted after the installation of the BMP and the permit limitation should include a
compliance schedule. Additionally, the determination of specific limits for benzene should be
subject to the considerations noted in the general comments;
b) -Xylene-limitation (001):-Similar to benzene, xylene should also be included in the permit with a
14AD t monitoring requirement and an RPA should be conducted when sufficient data are available. At a
'�)42cF¢c9-- minimum the RPA should be based on the existing monitoring conducted after the installation of
"c`1000 f/
the BMP ,and the permit limitation should include a compliance schedule. Additionally, the
4 da-+C,F4G• determination of specific limits for xylene should be subject to the considerations noted in the
U general comments;
c) (MTBE limitation 001 and 002 : MTBE has not previously been monitored at outfall 001.
A�),AConsequently, a limitation should not be imposed without first requiring monitoring and
performing an RPA. Additionally, it is not appropriate to introduce a limit for MTBE, which has
not previously been monitored at outfall 001 without, at a minimum, including a compliance
schedule for that parameter. MTBE should therefore be included in the permit with a monitoring
requirement and an RPA conducted with limits and a compliance schedule, if necessary,
introduced when justified by additional data. Additionally, the determination of specific limits
for MTBE should be subject to the considerations noted in the general comments;
Additionally, the 11.6 ug/L value for MTBE is apparently based on a recommended groundwater
standard within the Department.5 However, a level of 11.6 ug/L MTBE as a groundwater water
quality standard is conservative with regard to protection of human health. Additionally, the
standard should be evaluated based on medical and toxicological evidence. EPA has not adopted
a Maximum Contaminant Level (MCL) for MTBE; however, based on available research data,
EPA and the U.S. National Research Council have concluded that MTBE is not likely to be
harmful to people at levels typically found in the environment.6, 1 Furthermore, due to its high
a USEPA's "Interim Permitting Approach for Water Quality-Based Effluent Limitations in Storm Water Permits",
August 20, 1997, available at http://www.epa.gov/owm/pipes/storm/misc/swpol.txt/.
s.Luanne K. Williams,North Carolina's Department of Health and Human Services(June 19, 2000)
6 Melnick et al, 1997, "Potential Health Effects of Oxygenated Casolines," Chapter 4 in"Interagency Assessment of
Oxygenated Fuels,"prepared for the Office of Science and Technology, Executive Office of the President, 38 p.
7 U.S. EPA, 1997, "Fact Sheet, Drinking Water Advisory: Consumer Acceptability Advice and Health Effects
Analysis on Methyl Tertiary-Butyl Ether(MTBE)," U.S. Environmental Protection Agency, Office of Water 4304,
EPA-822-F-97-009

i1
Ms. Teresa Rodriguez
May 2, 2001
Page 6
water solubility and low octanol/water partition coefficient, the low potential of MTBE to
bioaccumulate should also be considered. Studies by the U.S. Geological Survey on sediments
show that MTBE will not accumulate in aquatic environments;$
Additionally, any standards established for MTBE should be the subject of a public notice and
comment period to allow input from potentially impacted public and industry representatives. At
a minimum, such an opportunity should be provided prior to the inclusion of limits in a draft
permit;
d) pH monitoring (001 and 002): pH monitoring was removed from terminal permits by the
Department in 1996 and apparently was inadvertently included in 2001. The monitoring
requirement for pH should therefore be removed;
e) 1, 2 Dichloroethane (002): The apparent application of the ground-water standard for 1, 2
k� 4 dichloroethane to surface water is inappropriate without providing industry the opportunity to
review and comment on the proposed standard. Therefore, 1, 2 dichloroethane should be
included for outfall 002 in the proposed permit with a monitoring requirement. Additionally, the
determination of specific limits for 1, 2 dichloroethane should be subject to the considerations
k noted in the general comments;
f) Naphthalene, rf3uorene, and phenanthrene (002):' These compounds have been previously
�pkrd, monitored at outfall 002 and results of the monitoring have not indicated their presence in the
j�O&t,,C'u morj. discharge. The requirement to continue monitoring these compounds should therefore be
o rn�r�c�12 removed. At minimum, continued monitoring should be justified in the permit fact sheet;
g) Naphthalene (001): Although naphthalene is a compound present in distillate products, its low
solubility indicates that it is not a better indicator for the presence of petroleum compounds in
stormwater than BTEX. The requirement to monitor naphthalene is therefore unnecessary and
should be removed;
h) Phenol (001 and 002): In developing the RPA for phenol for outfall 001, the Department should
consider the comments made regarding the wasteload allocation calculations in the general
(� comments. Furthermore, a RPA should be conducted prior to including limits for phenol at
n outfall 002, at which previous monitoring has not detected phenol. Facility activities do not
include and have not included the use or manufacture of phenolic compounds. Additionally,
L phenol biodegrades readily and should be considered as4 non-persistent chemical in surface
��. water. The requirement to monitor and limit phenols should therefore be removed; however, at a
minimum, a mass limit and a compliance schedule should be allowed instead of a concentration
limit based on the wasteload allocation;
Additionally, the phenol standard is possibly being misapplied in that phenol, as phenol, is non-
toxic to aquatic life and has no human health impacts and the specific chemical compound phenol
has no taste and odor effect at this level. Apparently, the proposed limit on the specific chemical
compound phenol is based on the non-specific total phenolics parameter in North Carolina's Title
$ Bradley et al, 1999, "Aerobic Mineralization of MTBE and tent-Butyl Alcohol by Stream-Bed Sediment
Microorganisms," Environ, Sci.Technology. 1999, 33, 1877-1879

' Ms. Teresa Rodriguez
May 2, 2001
Page 7
15A, Chapter 2, Subchapter 213, Section 0.0216(3)(d), which references chlorinated phenols as
the technical basis for the 1 ug/L criterion. Conversely, EPA's human health criterion for
drinking water and fish ingestion for the specific chemical phenol is 1200 ug/L and for phenol's
organoleptic effects is 300 ug/L. There are no aquatic life criteria for phenol, but acute and
chronic toxicity are both low. Specifically, the Department may be confusing the specific
chemical phenol with chlorinated phenols in its standards, which are designed to limit
chlorophenols because of their organoleptic effects;
i) Oil and Grease (001 and 002): The sampling method for oil and grease described in the permit
footnote is neither appropriate nor representative for monitoring point source discharges such as
the outfall for the Charlotte terminal. It is also not consistent with EPA sampling procedures and
techniques.' This footnote.should therefore be removed from the permit; and,
j) Turbidity (001 and 002): the permit footnote pertaining to turbidity is confusing as exemplified
by the Department's need to clarify its meaning in the cover letter to the permit. Apparently, the
proposed requirement for turbidity is monitoring. The footnote should therefore be removed or,
at a minimum, stated clearly in the permit.
3. Other Permit Comments
a) The map attached to the permit indicates the discharge point of the terminal adjacent to the
? ExxonMobil terminal and should be corrected;
b) The supplement sheet incorrectly indicates that stormwater from the containment pad,and loading
ov, rack areas flows through a holding pond. Stormwater and washwater from these areas flows
through an oil/water separator, is pumped to a retention tank, and is pumped through a carbon
filtration system prior to discharge; - -
c) The supplement sheet does not indicate the presence of washwater in the discharge from the
O,L loading rack and-containment pad areas. Potable water may be used for wash-down activities on
a de-minimus basis at the containment pad and loading rack areas. Additionally, on a routine
basis, potable water is used to test the fire suppression system at the loading rack as part of a
necessary maintenance program. This fire test water is necessarily discharged through the
stormwater conveyance system and should be included in the list of acceptable discharges; and,
d) The supplement sheet indicates that a water pollution control system is utilized for outfall 001 at
the Charlotte terminal. This system should be more appropriately described as aBMP.
9 EPA NPDES Compliance Inspection Manual, 300-B-94,014, September 1994

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State of North Carolina
• Department of Environment
and Natural Resources �r
Division of Water Quality
Michael F. Easley, Governor C D E ■�
William G. Ross, Jr., Secretary
Kerr T. Stevens, Director NORTH CAROLSNA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
April 2, `001
MEMORANDUM
To Britt setzer
R E C" E I Vff OE:ffi 0
NC DEN12 / DEH / Regional Engineer
!!klooresville Regional Office/
APR 0 4 2001
From: "feresa Rodriguez
NI>DEs Unit IN LODENR
Division of Environmental Health
subiect: Review of Draft NPDES Permit NC0004839 I luh,lir;Water Supply Section
ExxonMobil Refining and Supply Company MC --;t ;;ville Regional Office
Mecklenburg County
Please indicate below your agency's position or viewpoint on the draft permit and return this form by
May 2, 2001. II' you have any questions on the draft permit, please contact me at the telephone number
or e-mail address listed at the bottom of this page.
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i3I s1'O�sl (Check one)
PI/CDnC'LIr 'vilh the issuance of this permit provided the facility is operated and maintained properly, the
Stated effluent limits are met prior to discharge, and the discharge sloes not contravene the designated
.eater quality standards.
❑ Concurs with issuance of the above permit. provided the following conditions are met:
=iig,,, 14 �&UU4❑ R pUALITYOpposes the issuance of the above permit, based on reasons slatd3.RANCH
Signed Date: 4Z-11�1
1617 Mail Service Center,Raleigh,North Carolina 27699-1617 919 733-5083,extension 595 (fax)919 733-0719
VISIT US ON THE INTERNET @ hnp:/m2o.enr.state.nc.us)NPDES Teresa.Rodriguez@ ncrnail.net

ExxonMobil
Refining and Supply Company
Charlotte Terminal
PO Box 82
Charlotte,NC 28130
E1&onMobH
Refining & Supply
May 24, 2001 t.`---
Mr. Dave Goodrich -
NCDENR—DWQ-NPDES Unit
1621 Mail Service Center --
Raleigh, NC 27699-16 l 7
Re: Draft NPDES Permit
ExxonMobil Charlotte Terminal �-
Permit#: NC0004839
Dear Mr. Goodrich:
ExxonMobil is hereby presenting additional comments relevant to the proposed NPDES permit issued for
its Charlotte, NC fuels distribution terminal. The submittal of additional comments is consistent with our
request for an extension of the comment period through the close of business on May 25, 2001, to which
we believe we are entitled. This request and its basis were included with our other comments on the
proposed permit in our letter to Ms. Teresa Rodriguez of the Division of Water Quality dated May 2,
2001.
The focus of our comments in this letter, as outlined below, is the health basis for the MTBE limit of 11.6
µg/L.
The rationale for the state of North Carolina's proposed limitation is a recommended groundwater quality
standard for MTBE that was developed in a memorandum from Luanne Williams to Carl Baily, dated
June 19, 2000, As documented in that memo, the specific basis for the standard was the
lymphomas/leukemias that were observed in female Sprague-Dawley rats following gavage exposure
from the study by Belpoggi et al., in 1995.
ExxonMobil takes exception to this basis for developing the proposed groundwater standard for the
following reasons:
1. The IARC, the U.S. National Toxicity Program, the U.S. EPA, and the California Science Advisory_
Board have made conclusions that are contradictory to those of NC-DENR.
The toxicological database on MTBE has been extensively reviewed and evaluated in recent years by
various internationally recognized regulatory and authoritative bodies. These include, among others,
the International Agency for Research on Cancer (IARC), the National Toxicology Program, the US
EPA, and California's Science Advisory Board for Proposition 65. Collectively, these organizations
have concluded that the weight of evidence suggests MTBE is not likely to pose a cancer hazard at
the concentrations in which it is present in the environment. Specifically:
• IARC's overall evaluation of MTBE resulted in a Group 3 classification. That is, MTBE is not
classifiable as to its carcinogenicity to humans. This conclusion was based on inadequate
evidence in humans and only limited evidence for carcinogenicity in experimental animals;

y
.. t
Mr. Dave Goodrich
May 24, 2001
Page 2
• The US National Toxicology Program, after reviewing all available data, chose not to list
MTBE in its "Report on Carcinogens"; and,
• The Science Advisory Board to the State of California voted not to list MTBE under The Safe
Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65) as one of the chemicals
"known to the state" to cause cancer.
2. NC-DENR used an inappropriate extrapolation procedure in development of their proposed
groundwater standard.
The linear extrapolation procedure used by NC-DENR to derive the 11.6 µg/L MTBE value is a
procedure that is generally used for potent DNA reactive-carcinogens. However, the available
database indicates that MTBE is not genotoxic, and therefore a linear extrapolation procedure is not
appropriate for estimating potency. Moreover, the cancers that were observed in laboratory animals
occurred as a result of processes that were species and sex specific, and by mechanisms that appeared
to have a biological threshold. Those cancer findings were therefore not applicable to humans
exposed to doses of MTBE that are lower than those used in the laboratory animal studies by many
orders of magnitude. The linear extrapolation procedure is therefore inappropriate and results in an
overly conservative value.
3. The USEPA has not issued drinking water MCLs for MTBE.
Although the USEPA has recognized the potential for exposure to small amounts of MTBE in water,
it has not classified MTBE as a known or probable carcinogen for humans. EPA's MTBE Drinking
Water Advisory also discusses the uncertainties associated with current carcinogenic risk assessments
for MTBE and concludes that the data do not support quantitative estimation of risk from MTBE at
low exposures. In addition, the Blue Ribbon Panel appointed by USEPA concluded that the great
majority of MTBE detections have been well below levels of public health concern.
In summary, ExxonMobil believes that NC-DENR has proposed a MTBE groundwater standard that is
overly conservative and that is unjustified in light of existing scientific evaluation, More specifically,
ExxonMobil takes exception to this value because we do not believe it is based on the most appropriate
scientific evaluation of available data, nor do we believe it reflects the conclusions of several
internationally recognized bodies regarding the cancer hazards of MTBE, Consequently, NC-DENR
should remove the 11.6 µg/L limitation from the proposed NPDES permit for the Charlotte terminal.
Sincerely,
Steve D. G �n, P.E.
Environmental Advisor
C: R.E. Gaston,Terminal Superintendent
Paul K. Cole, ExxonMobil Law Department

ExxonMobil 1
Refining and Supply Company
• Charlotte Terminal
P.O. Box 82
Charlotte, NC 28130
E�®nMobH
Refining & Supply
1
May 24, 2001
Mr. Dave Goodrich '
NCDLNR—DWQ-NPDES Unit
1621 Mail Service Center
Raleigh, NC 27699-1 6 1 7
Re: Draft NI DES Permit
LxxonMobil Charlotte Terminal
Permit#: NC0004839
Dear Mr. Goodrich:
The purpose of this letter is to reiterate our request for a meeting with the Department to discuss its
permitting strategy for our Charlotte, NC fuels distribution terminal. This request was stated with our
previous comments in our letter to Teresa Rodriguez of the Division of Water Quality, dated May 2,
2001. In accordance with the requested extension of the comment period, the reason for which was
presented in our letter of May 2, 2001, we have also submitted comments on the proposed MTBE
groundwater standard that was used by the Department in development of the proposed effluent
limitation of 11.6 µg/L.
We believe the Department should remove the proposed MTBE limitation from the draft permit and
should follow the strategy presented in our previous letter in developing the permit for the Charlotte
terminal. In addition, we wish to meet with the Department to discuss its basis for developing the
proposed limits, which was not fully explained in the supplemental documents that were provided in
response to our request for a fact sheet. In addition, the information that was provided suggests that the
approach used by the Department is inconsistent with the requirements of 15A NCAC 2I3.0203 and 15A
NCAC 213.0202 (68). Those provisions require the DENR to follow EPA guidance in its strategy as
indicated in our previous letter. 15A NCAC 213.0206 also indicates that the mean annual flow should be
used in the case of protection of human health from carcinogens rather than the 7Q10 flow, which was
apparently used by the Department. Mixing zones in Long Creek should also have been considered in
the Department's analysis according to NCAC 15A 213,0204.
In conclusion, we believe the Department has not provided an explanation of the basis for its permitting
strategy in a fact sheet. Neither has the Department followed the approach specified in 15A NCAC
213.0201 (c) (2), which indicates that a determination should be made to determine whether the discharge
uses the available load capacity of the receiving waters. We therefore believe that a meeting is
appropriate in order to discuss the Department's permitting strategy. We also believe that we are entitled
to have the opportunity to provide additional comments when the basis has been explained before a final
permit is issued. Failure of the Department to grant this request would be, in our opinion, a denial of our
due process on such an important issue.

Mr. Dave Goodrich
4,
May 24, 2001
Page 2
Thank you for considering our request; we look forward to receiving your response.
Sincerely,
r-y10
Steve DqGif , E.
Environmental Advisor
C: R.E. Gaston, Terminal Superintendent
Paul K. Cole,ExxonMobil Law Department

Division of Water Quality �f
1617 Mail Service Center
Raleigh, NC 27604
Phone: [phone] NCDENR
NORTH CAROLINA DEPARTMENT Or
ENVIRONMENT AND NATURAL RESOURCES
FaX
To: Steve Giffin From: Teresa Rodriguez
Fax: [phone] Date: 5/03/01
Phone: Phone: [phone] ext. 595
Re: Phenol limits Pages: 3
•Comments:
Mr. Giffin:
I'm enclosing the policy for phenol developed for the Paw Creek terminals. When I
was reviewing the calculations for your particular permit I noticed I had used the
incorrect maximum flow to calculate the phenol limit for Outfall 001. The correct
maximum flow for outfall 001 is 0.3464 MGD, not .4563 MGD. The correct limit
should be 0.15 mg11. I have changed this in the permit.
If you have any questions please call me,
Teresa

ExxonMobil
•' Refining & Supply Company
Exxon Terminal
P.O. Box 82
Paw Creek, North Carolina 28130
E onMobH
Refining & Supply
January 23, 2001
[J'u JAN 2 5 2001
North Carolina Department of Environment and Natural Resources
Division of Water Quality/NPDES Unit
1617 Mail Service Center PIDIN
Raleigh, NC 27699-1617
Re: Application for Renewal of NPDES Permit : NC0004839
ExxonMobil Charlotte Terminal
Dear NPDES Permit Coordinator:
Attached is the Short Form C required to effect renewal of the above referenced NPDES permit. A name
change request reflecting the new name of the facility owner is also enclosed.
If there are any questions concerning this application please call Steve Giffin at 410-280-9750 or me at
704-3 99-5696.
;Aoe�
1'0e�
Robert E. Gaston
Terminal Superintendent
C: Steve D. Giffin, Environmental Advisor