[Federal Register Volume 65, Number 78 (Friday, April 21, 2000)]
[Notices]
[Pages 21419-21422]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-10039]



[[Page 21419]]

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ENVIRONMENTAL PROTECTION AGENCY

[SW-FRL-6583-2]


Notice Proposing To Reissue a Variance From Land Disposal 
Restrictions Granted to Exxon Mobil Corporation, Billings, MT

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of proposed decision.

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SUMMARY: This is a notice to interested parties that EPA is proposing 
to reissue a no-migration variance for land disposal of hazardous waste 
to Exxon Mobil Refining & Supply Company Billings Refinery (``Exxon''), 
a division of Exxon Mobil Corporation, formerly known as Exxon Company 
U.S.A. Authority for the decision has been delegated to the EPA 
Regional Administrator. The original July 27, 1993 variance (58 FR 
40134) approved under Resource Conservation and Recovery Act 
regulations (40 CFR 268.6) allowed Exxon to place certain untreated 
hazardous wastes subject to the RCRA land disposal restrictions (42 
U.S.C. 36901 et. seq.) at their Billings (Montana) refinery South Land 
Treatment Unit (SLTU). In the original variance, the unit was referred 
to as the New South Land Treatment Unit. Exxon submitted a request to 
EPA on March 24, 1998 for renewal of this no-migration variance in 
conjunction with their State of Montana hazardous waste permit 
reissuance. Exxon also petitioned to amend the variance by adding the 
newly listed hazardous waste, Petroleum Refinery Primary Oil/Water/
Solids Separation Sludge (EPA hazardous waste code F037). The proposed 
variance reissuance includes the F037 waste stream, ``Primary Sludge,'' 
generated at the Exxon Billings Refinery.
    In granting the original variance, we concluded that Exxon 
demonstrated to a reasonable degree of certainty that hazardous 
constituents would not migrate out of the land treatment facility at 
levels exceeding no-migration criteria for as long as the wastes remain 
hazardous. We have reviewed the SLTU monitoring data submitted by Exxon 
for the period the variance was in effect along with other relevant 
information, and it still supports our original conclusion on Exxon's 
no-migration demonstration. We also concluded that Exxon adequately met 
the conditions of the original variance, which were included to ensure 
compliance with their no-migration demonstration.
    The present proposal considered how the terms of the original 
variance were affected by certain changes in waste application 
techniques and closure requirements incorporated into the recently 
issued Montana hazardous waste permit (No. MTHWP-99-02) and one failure 
to correctly manage a waste stream whose hazardous status had changed 
during the term of the original variance. We concluded that these 
factors did not materially affect the overall demonstration of no-
migration. The proposed variance reissuance again includes specific 
conditions tailored to reflect additions of a newly hazardous waste 
stream (F037), modifications to how no-migration standards apply to 
specific SLTU monitoring systems, additional monitoring requirements, 
and improvements to the Exxon waste application tracking system. 
Certain conditions of the original variance are also included. The full 
set of variance conditions are presented below.
    RCRA regulations require that we provide for public comment on a 
proposed no-migration variance decision. In addition to seeking written 
comments through this notice, we have elected to hold a public hearing 
in Billings, Montana to gather comment on this proposed decision from 
the local citizens near Exxon's land treatment facility and other 
interested parties. All comments received will be entered into the 
public record for this decision making process. Details appear below in 
the DATES section of this document. A final decision will be made by 
EPA after considering and responding to public comments. We will then 
publish a notice in the Federal Register of our decision on the 
reissuance of the variance and the addition of Primary Sludge (F037). 
Copies of the statement of basis for the proposed decision are 
available in the record for today's document and can be requested from 
Tina Diebold at the address or telephone number listed below.

DATES: Comments on the proposed decision must be received on or before 
June 5, 2000. In addition to the written comments received at EPA's 
Montana Office, written and oral comments on the proposed decision also 
will be accepted by the Hearing Officer at the public hearing in 
Billings, Montana. The public hearing is scheduled for May 23, 2000 
from 6 p.m. to 8:30 p.m.

ADDRESSES: Comments on the proposal should be sent to EPA at the 
following address: Tina Diebold, Mail Code 8MO, Montana Office, U.S. 
EPA Region VIII, 301 S. Park, Drawer 10096, Helena, Montana 59626-0096. 
The public hearing will be held at the Parmly Library at 510 North 
Broadway, Billings, Montana (large, open meeting room on third floor).
    A copy of the record supporting this proposal is available to the 
public at the Parmly Library at 510 North Broadway, Billings, Montana, 
and is available for public review during regular library hours. 
Another copy of the record is available in Helena, Montana, at the EPA 
Region VIII, Montana Operations Office, Federal Building, 301 South 
Park. The public may make arrangements to view the documents in Helena 
by calling Tina Diebold at (406) 441-1130. The record is available for 
inspection in Helena from 8 a.m. to 4 p.m., Monday through Friday, 
except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Tina Diebold, Mail Code 8MO, Montana 
Office, U.S. EPA Region VIII, 301 S. Park, Drawer 10096, Helena, 
Montana 59626-0096, at (406) 441-1130.

SUPPLEMENTARY INFORMATION: Wherever ``we'' is used throughout this 
document, it refers to EPA.

A. What Conditions and Reporting Requirements Are Proposed for the 
Exxon No-Migration Variance Reissuance?

    As part of this reissuance of the no-migration variance and 
addition of Primary Sludge (F037), we propose that Exxon comply with 
the following conditions. These conditions are in addition to those 
required of Exxon under 40 CFR 268.6. EPA would directly enforce these 
conditions, and a violation of a condition would constitute a violation 
of the RCRA land disposal restrictions. Unless otherwise notified by 
EPA, Exxon shall provide the required notices and reports to the EPA 
Region VIII Montana Operations Office, Federal Building, 301 South 
Park, Drawer 10096, Helena, MT, 59626. Exxon shall provide a separate 
copy to the State of Montana of any report or notice required by the 
variance if the information is not combined with the reports required 
under its Montana hazardous waste permit. Exxon shall provide copies to 
the State at the address specified for its Montana hazardous waste 
permit reporting requirements.
    We interpret the no-migration standard to mean that concentrations 
of hazardous constituents cannot exceed EPA-approved health-based 
levels in any environmental medium at the boundary of the land disposal 
unit. Hazardous constituent levels exceeding those presented in Table 1 
of this document constitute migration into ground water at the unit 
boundary, as measured by soil-pore liquid and below

[[Page 21420]]

treatment zone (BTZ) soil-core monitoring, and as measured by ground 
water monitoring under the Exxon Montana hazardous waste permit and as 
defined below. In the event that Exxon should detect other RCRA 
hazardous constituents (defined in 40 CFR part 261, appendix VIII) 
above health-based levels, this event would also be subject to the 
notification requirements in 40 CFR 268.6(f). Definitions of the unit 
boundaries (i.e., points of compliance for no-migration purposes) 
remain the same as in the original variance (57 FR 10478). Metals 
levels in the SLTU zone of incorporation (ZOI) soils (the top 23 
centimeters of the treatment zone) exceeding the limits listed in item 
1.a. below are also evidence of a no-migration standard exceedance.
    In accordance with 40 CFR 268.6(k), the proposed variance will be 
valid for up to ten years from the date of EPA approval of the 
petition, but no longer than the term of Exxon's Montana hazardous 
waste permit, unless the permit is renewed or reissued.

1. Montana Hazardous Waste Permit Conditions

    Exxon must comply with conditions of the Montana hazardous waste 
permit effective June 28, 1999 (No. MTHWP-99-02) regarding 
characterization of wastes disposed of at the SLTU, and monitoring of 
ground water, soil and soil-pore liquids at that unit. Exxon must 
provide the results of this characterization and monitoring to EPA on 
the same schedule as they are provided to the State of Montana under 
Exxon's Montana hazardous waste permit.
    In addition, Exxon must follow the monitoring provisions below 
specific to this variance, which are intended to supplement the 
existing Montana hazardous waste permit conditions. Exxon may provide 
the information required as a condition of the variance to EPA in the 
annual reports required by its Montana hazardous waste permit. Exxon 
shall submit annual reports for the previous calendar year by April 30.
a. ZOI Metals Loading Limit
    Exxon shall determine if any of the following risk limits have been 
exceeded when it evaluates the annual SLTU ZOI soil samples for the 
metals loading limits under its Montana hazardous waste permit: 31 mg/
kg for antimony; 15 mg/kg for arsenic; 2 mg/kg for beryllium; 140 mg/kg 
for total chromium; 400 mg/kg for lead; and 7 mg/kg for mercury. In the 
event one or more of these criteria are exceeded, Exxon may only place 
wastes on the SLTU areas(s) for which the metals concentrations are 
less than or equal to the in-soil concentration limits. Exxon shall 
submit the analytical results and comparisons in an annual report to 
EPA. Exxon shall report exceedances of these limits to EPA within ten 
days of receiving the analytical results.
b. Soil-Pore Liquid Monitoring
    Exxon shall evaluate the following metals as part of semi-annual 
SLTU soil-pore lysimeter monitoring requirements under the Montana 
hazardous waste permit: antimony, arsenic, barium, beryllium, cadmium, 
chromium, lead, mercury, nickel, selenium, vanadium, and zinc. Samples 
from each of the three SLTU lysimeters shall be .45-micron filtered 
prior to analysis for metals. SW-846 \1\ or equivalent analytical 
methods shall be used which can provide reporting limits of .001 mg/l, 
except .0002 mg/l for mercury. Exxon shall attempt to collect 
sufficient sample volumes to meet these performance criteria, following 
the general analytical priority scheme in its Montana hazardous waste 
permit. Should sample volumes be insufficient, Exxon shall investigate 
collecting additional sample volumes in a reasonable time frame for 
metals analysis once the Montana hazardous waste permit conditions have 
been met. Additionally, analyses of soil-pore organic monitoring 
constituents shall meet the SW-846 estimated quantitation limits (EQL) 
specified for water samples in Exxon's Montana hazardous waste permit 
and as listed in Table 1, to the extent possible.
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    \1\ These methods are found in the third edition of ``Test 
Methods for Evaluating Solid Waste Physical/Chemical Methods,'' EPA, 
SW-846, which is available from the Government Printing Office 
(GPO). This compendium of EPA test methods is commonly referred to 
as ``SW-846'' and we will use this term to refer to the compendium 
throughout this document.
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c. Soil-Pore Liquid Monitoring Evaluation and Reporting
    Exxon shall compare the organic hazardous constituents and the 
metals results to the leachate soil-pore health-based standards 
identified in Table 1 below. Exxon shall submit the analytical results 
and comparisons including information on sample volumes collected, 
analytical methods used, and EQLs achieved for all sample constituents, 
in an annual report to EPA. Exxon shall report exceedances of these 
limits to EPA within ten days of receiving the analytical results. 
Exxon shall notify EPA and the State if sufficient sample volumes 
cannot be collected or EQLs cannot be achieved in any semi-annual 
sampling period.
d. BTZ Soil-Core Monitoring
    When collecting the five (5) annual soil cores from the SLTU Below 
Treatment Zone (BTZ) as required by its Montana hazardous waste permit, 
Exxon shall also collect intermediate level treatment zone soil samples 
at three depth intervals of 2-2.5 feet below ground surface (bgs), 3-
3.5 feet bgs, and 4-4.5 feet bgs and in the BTZ itself (5-5.5 feet 
bgs), sufficient for analyses of oil and grease and soil pH. Oil and 
grease and soil pH results shall be reported for the four depth 
intervals in each of the five soil core samples. Exxon shall use an oil 
and grease analytical method which can provide detection limits in the 
range of 10 to 100 mg/kg consistent with the Montana hazardous waste 
permit. Exxon also shall analyze any BTZ resamples required under the 
Montana hazardous waste permit for oil and grease and soil pH. Exxon 
shall submit the results of the annual BTZ sampling (including the pH 
and oil and grease results from the intermediate levels) in an annual 
report to EPA. Exxon shall submit the results of any resampling to EPA 
on the same schedule as provided to the State under Exxon's hazardous 
waste permit.
e. Evaluation of BTZ Soil-Core Monitoring
    Analyses for organic monitoring constituents shall meet soil low-
level required EQLs as specified in Exxon's Montana hazardous waste 
permit and as specified in Table 1 below. Exxon shall compare the 
results of BTZ soil samples with soil-core health-based standards 
identified in Table 1 of this document. Exxon shall submit the 
analytical results and comparisons in an annual report to EPA. Exxon 
shall report exceedances of these limits to EPA within ten days of 
receiving the analytical results.

[[Page 21421]]



                 Table 1.--Proposed Exxon No-Migration Variance Leachate and Soil-Core Standards
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                                                                                      Soil-core standards  (mg/
                Constituents                   Leachate soil-pore  standards (mg/l)              kg)
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I. Volatiles:
    Benzene.................................  .005 (EQL)--MCL                        .002 (EQL)
    Ethylbenzene............................  .7--MCL                                .65
    Toluene.................................  1--MCL                                 .56
    Xylene(s)...............................  10--MCL                                9.8
II. Semi-Volatiles:
    Anthracene..............................  10--Risk                               620
    Benzo(a)anthracene......................   .0001 (EQL)--Risk                     .08 (EQL)
    Benzo(b)fluoranthene....................  .0001(EQL)--Risk                       .25 (EQL)
    Benzo(a)pyrene..........................  .0002(EQL)--MCL                        .41
    Chrysene................................  .0012 (EQL)--Risk                      9.3
    Fluoranthene............................  1.4--Risk                              300
    1-Methylnaphthalene.....................  NS                                     NS
    Naphthalene.............................  1.4--Risk                              5.9
    Phenanthrene............................  NS                                     NS
    Pyrene..................................  1--Risk                                220
    2,4-Dimethyl phenol.....................  .7--Risk                               .43
    Phenol..................................  21--Risk                               5.4
    Cresol (o-).............................  1.8--Risk                              .69
III. Metals:
    Antimony................................  .006--MCL                              Not proposed
    Arsenic.................................  .05--MCL                                   Do.
    Barium..................................  2--MCL                                     Do.
    Beryllium...............................  .004--MCL                                  Do.
    Cadmium.................................  .005--MCL                                  Do.
    Chromium................................  .1--MCL                                    Do.
    Lead....................................  .015--MCL                                  Do.
    Mercury.................................  .002--MCL                                  Do.
    Nickel..................................  .7--Risk                                   Do.
    Zinc....................................  10--Risk                                   Do.
    Selenium................................  .05--MCL                                   Do.
    Vanadium................................  .24--Risk                                  Do.
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    An (EQL) indicates a risk-based standard lying below the expected 
low-level quantification limit for the routine analytical methods 
assumed from Exxon's Montana hazardous waste permit. Typical 
quantification limits would be: SW-846 Method 8260--.005 mg/l aqueous 
and .005 mg/kg clean soils and Method 8270--.01 mg/l aqueous and .33 
mgl/kg clean soil. NS indicates no standard.

2. Annual Benzene Loading Limit

    The total amount of benzene that may be disposed of at the SLTU may 
not exceed a cumulative mass loading of 49 Kg per calendar year. Exxon 
must determine the benzene content of each wastestream, including each 
load of Primary Sludge (F037) prior to placement at the land treatment 
unit. Representative samples of each wastestream must be analyzed for 
benzene as they are generated during the land application season in 
accordance with the promulgated edition of SW-846. The term ``as 
generated'' means each time the wastes are removed from the wastewater 
system, created through a spill, or a tank is cleaned out, and the 
wastes are taken or will be taken to the land treatment unit, which may 
be several times a year. A tracking system must be in place which 
continually estimates and updates the cumulative benzene waste loading 
during the operating season. Exxon must submit a summary of these waste 
analyses demonstrating its compliance with the loading limit to EPA in 
an annual report. When the 49 Kg benzene limit is reached, Exxon must 
not dispose of any additional waste containing detectable levels of 
benzene at the SLTU until the next calendar year. Exxon shall notify 
EPA when the 49 Kg limit is reached within ten days of receiving the 
analytical results.

3. Waste Characterization

    Exxon must identify in the annual report to EPA the following 
additional information for each applied waste at the SLTU: the location 
of waste generation (e.g., Tank 17 sewer, Tank 108 contaminated soil); 
analytical results of waste determination for any wastes for which the 
hazardous status was not known when it was generated, mass of waste; 
application date(s); the hazardous waste code (if any); and the matrix 
(e.g., soil or sludge). In the report, Exxon must distinguish between 
the F037 waste generated from the sewer (e.g., ``F037 sewer sludge'') 
and the F037 waste generated from the Alkyllation Unit Neutralization 
Basins (e.g., ``F037 lime sludge''). In the annual report, Exxon must 
also include the total quantity of waste applied at the SLTU during the 
last operating season and a break down of the total quantity of 
hazardous and of non-hazardous waste.

4. Application of F037 Sewer Sludge

    Exxon's application of Primary Sludge generated from the sewer 
system (F037 sewer sludge) to the SLTU is restricted to times when 
Exxon also applies API Separator Sludge (K051). Exxon must combine the 
F037 sewer sludge with the API Separator Sludge prior to or during 
application at the SLTU. Exxon shall incorporate this condition in its 
waste tracking system to ensure that any time F037 sewer sludge is 
cleared for application to the SLTU, it is accompanied by K051 waste.

5. Application of F037 Lime Sludge

    Exxon's application of Primary Sludge generated from the 
Alkyllation Unit Neutralization Basin (F037 lime sludge) to the SLTU is 
limited to when it has determined pH adjustment of the ZOI

[[Page 21422]]

soils is needed according to the applicable criteria and methods 
identified in its Montana hazardous waste permit. For the years in 
which Exxon uses F037 lime sludge to adjust the pH of the ZOI soils at 
the SLTU, Exxon must submit to EPA the following information in the 
annual report: pH of the F037 lime sludge applied to the SLTU, and the 
other measurements and tests used to determine the need for pH 
adjustment as well as the quantity of F037 lime sludge applied and the 
quantity of any other substance (e.g., lime) used to adjust the pH of 
the ZOI soil at the SLTU.

6. Waste Tracking

    As part of its waste tracking process, Exxon must confirm receipt 
of analytical results for any wastes for which the hazardous status is 
not currently known prior to application of the waste at the SLTU. 
Exxon must comply with its Montana hazardous waste permit conditions 
with regard to restrictions on the application of waste to the SLTU, 
such as any restrictions based on the pH of the waste.

7. Information Requests

    Upon request by EPA, Exxon shall provide to the EPA within a 
reasonable time, any relevant information requested to determine 
compliance with the conditions of this variance.

8. Access

    Exxon shall allow EPA, or authorized representatives, upon the 
presentation of credentials and other documents as may be required by 
law to: (a) inspect at reasonable times any records, facilities, 
equipment (including monitoring and control equipment), practices, or 
operations related to the disposal of restricted hazardous wastes at 
the SLTU; and (b) sample or monitor at reasonable times, for the 
purposes of assuring compliance with the conditions of this variance or 
to determine migration or as otherwise authorized by RCRA, any wastes 
intended or proposed for disposal at the SLTU and the soil, air, soil-
pore liquids or ground water in or surrounding the SLTU.

    Dated: April 13, 2000.
 Stephen S. Tuber,
Acting Regional Administrator, Region VIII.
[FR Doc. 00-10039 Filed 4-20-00; 8:45 am]
BILLING CODE 6560-50-P