[Federal Register Volume 60, Number 228 (Tuesday, November 28, 1995)]
[Notices]
[Pages 58623-58625]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-29035]



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ENVIRONMENTAL PROTECTION AGENCY
[FRL-5335-1]


Notice of Intent to Reissue an Exemption From the Land Disposal 
Restrictions of the 1984 Hazardous and Solid Waste Amendments (HSWA) to 
the Resource Conservation and Recovery Act (RCRA) Regarding Injection 
of Hazardous Waste to Cabot Corporation

AGENCY: Environmental Protection Agency.

ACTION: Notice of Intent to Reissue an Exemption to Cabot Corporation 
(Cabot) of Tuscola, Illinois, for the Injection of Waste Hydrochloric 
Acid and Specified Hazardous Constituents Found in Ground Water at the 
Tuscola Facility.

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SUMMARY: The United States Environmental Protection Agency (EPA or 
Agency) is today proposing to reissue an exemption from the ban on 
disposal of certain hazardous wastes through injection wells to Cabot 
Corporation for its site at Tuscola, Illinois. On November 6, 1990, the 
Agency issued Cabot an exemption for injection of certain hazardous 
wastes into Waste Disposal Well (WDW) No. 2 after determining that 
there is a reasonable degree of certainty that Cabot's injected wastes 
will not migrate out of the injection zone within the next 10,000 
years. On February 4, 1991, Cabot was granted an exemption to allow use 
of WDW No. 1 at the facility for the disposal of the same wastes 
injected through the WDW No. 2. The exemption was modified on November 
4, 1994, to include monitor well purge water. If granted, the proposed 
reissuance would allow Cabot to inject the RCRA 

[[Page 58624]]
regulated wastes D002, F003, and F039, which are already injected 
through WDWs Nos. 1 and 2, through WDW No. 3 and will add information 
gained as a result of the drilling of WDW No. 3 to the administrative 
record. WDW No. 1 will be closed after WDW No. 3 is put on line.

DATES: The EPA is requesting public comments on its proposed decision 
to reissue the exemption condition described above. Comments will be 
accepted until 45 days after the date of publication of the notice in 
local newspapers. Comments on any aspect of the no-migration 
demonstration and integrity of the deepwell disposal system are 
admissible because the exemption is proposed for reissuance in its 
entirety. Comments postmarked after the close of the comment period 
will be stamped ``Late''. A public information meeting and a public 
hearing to allow comment on this action may be scheduled if significant 
comments are received, and a notice of these meetings will be given in 
a local paper and to all people on a mailing list developed by the 
Agency. If you wish to request that a public hearing be held or to be 
notified of the date and location of any pubic hearing held, please 
contact the lead petition reviewer listed below.

ADDRESSES: Submit written comments, by mail, to: United States 
Environmental Protection Agency, Region 5, Underground Injection 
Control Branch (WD-17J), 77 West Jackson Street, Chicago, Illinois 
60604, Attention: Rebecca L. Harvey, Chief.

FOR FURTHER INFORMATION CONTACT: Harlan Gerrish, Lead Petition 
Reviewer, UIC Section, Water Division; Office Telephone Number: (312) 
886-2939; 17th Floor, Metcalfe Building, 77 West Jackson Street, 
Chicago, Illinois.

SUPPLEMENTARY INFORMATION:

I. Background

A. Authority

    The Hazardous and Solid Waste Amendments of 1984 (HSWA), enacted on 
November 8, 1984, impose substantial new responsibilities on those who 
manage hazardous waste. The amendments prohibit the land disposal of 
untreated hazardous waste beyond specified dates, unless the 
Administrator determines that the prohibition is not required in order 
to protect human health and the environment for as long as the waste 
remains hazardous (RCRA Sections 3004 (d)(1), (e)(1), (f)(2), (g)(5)). 
The statute specifically defined land disposal to include any placement 
of hazardous waste in an injection well (RCRA Section 3004(k)). After 
the effective date of prohibition, hazardous waste can be injected only 
under two circumstances:
    (1) When the waste has been treated in accordance with the 
requirements of Title 40 of the Code of Federal Regulations (40 CFR) 
Part 268 pursuant to Section 3004(m) of RCRA, (the EPA has adopted the 
same treatment standards for injected wastes in 40 CFR Part 148, 
Subpart B); or
    (2) When the owner/operator has demonstrated that there will be no 
migration of hazardous constituents from the injection zone for as long 
as the waste remains hazardous. Applicants seeking this ``no-
migration'' exemption from the ban must demonstrate to a reasonable 
degree of certainty that hazardous waste will not leave the injection 
zone until either:

    (a) The waste undergoes a chemical transformation within the 
injection zone through attenuation, transformation, or 
immobilization of hazardous constituents so as to no longer pose a 
threat to human health and the environment; or
    (b) The fluid flow is such that injected fluids will not migrate 
vertically upward out of the injection zone, or laterally to a point 
of discharge or interface with an underground source of drinking 
water (USDW), for a period of 10,000 years.

    The EPA promulgated final regulations on July 26, 1988, (53 FR 
28118) which govern the submission of petitions for exemption from the 
injection well disposal prohibition (40 CFR Part 148). Most companies 
seeking exemption have opted to demonstrate waste confinement (option 
(b) above) rather than waste transformation (option (a) above). A time 
frame of 10,000 years was specified for the confinement demonstration 
not because migration after that time is of no concern, but because a 
demonstration which can meet a 10,000 year time frame will likely 
provide containment for a substantially longer time period, and also to 
allow time for geochemical transformations which would render the waste 
immobile. The Agency's confinement standard thus does not imply that 
leakage will occur at some time after 10,000 years, rather, it is a 
showing that leakage will not occur within that time frame and probably 
much longer.
    The EPA regulations at 40 CFR 148.20(e) provide that any person who 
has been granted an exemption to the land disposal restrictions may 
request that the Agency reissue the exemption to include additional 
wastes, or modify any conditions placed on the exemption by the 
Director. If the petitioner complies with 40 CFR 148.20 (a), (b), and 
(c) the exemption shall be reissued. Reissuance allows reconsideration 
of all factors involved in the determination that land disposal through 
injection is protective of the health of persons. Cabot has submitted 
data from testing of WDW No. 3 that shows that the assumptions used in 
1990 to calculate the distance of migration of hazardous constituents 
were very conservative. In fact, the distance of waste migration can be 
expected to be considerably less than previously determined. Cabot has 
requested that the administrative record be updated to include this new 
information and to show that the earlier modeling results are 
considerably more conservative than necessary.
    Neither the existing exemption from the restrictions of the HSWA to 
RCRA nor this reissuance exempts Cabot from the duty to comply with 
other laws or regulations.

B. Facility Operation and Process

    The Cabot facility in Tuscola, Illinois, is a chemical 
manufacturing plant designed to produce fumed silica, SiO2 or 
silicon dioxide, which is used as an additive in many products. The 
central reaction in the manufacturing process is combination of silicon 
tetrachloride with oxygen and hydrogen to produce both fumed silica and 
hydrogen chloride vapor. Separation results in fumed silica, product 
hydrochloric acid, and wastewaters contaminated with hydrochloric acid 
which must be disposed of. This waste, along with rainwater runoff and 
seepage into a subsurface drainage system, are normally injected into 
Cabot's on-site, Class I hazardous waste injection wells.

C. Exemption

    The current exemption allows Cabot to inject wastes bearing RCRA 
waste codes D002, F003, and F039 into parts of the Franconia, Potosi, 
and Eminence Dolomites, the Gunter Sandstone Formation, and Oneota 
Dolomite found between 5,400 and 4,442 feet below the kelly bushing 
elevation in WDW No. 2 and extending radially 23,500 feet from WDW No. 
2.

D. Submission

    On August 15, 1995, Cabot submitted a written request that its 
exemption be reissued to change the condition that wastes be injected 
only through WDWs No. 1 and 2 to include WDW No. 3. WDW No. 3 was 
constructed to replace WDW No. 1 which has a limited capacity due to 
size of well elements, and it has had mechanical problems which 
threaten its usefulness. In addition, Cabot wished to add information 
relevent to the 

[[Page 58625]]
demonstration of no migration gained as a result of testing carried out 
during the construction of WDW No. 3. The submissions were reviewed by 
staff at the EPA to ensure that requirements of 40 CFR 
148.120(a)(2)(iv) were met and that the conclusions based on testing 
are consistent with the test data.

II. Basis for Determination

A. Mechanical Integrity of WDW No. 3

    On January 19, 1995, a standard annulus pressure test of WDW No. 3 
demonstrated the absence of leaks in the tubing, packer, and casing, 
and on January 20, a radioactivity tracer test was used to demonstrate 
the integrity of the annular seal and bottom-hole cement of WDW No. 3 
as required by 40 CFR 148.20(a)(2)(iv). The results of these tests were 
submitted as parts of the completion report for WDW No. 3, and are 
incorporated into the administrative record for this proposed decision.

B. Model Demonstration of No Migration

    The grant of an exemption from the land disposal restrictions 
imposed by the HSWA of RCRA is based on a demonstration that disposed 
wastes will not migrate out of the waste management unit, which is 
defined as the injection zone and is specifically those parts of the 
Franconia, Potosi, and Eminence Dolomites, the Gunter Sandstone 
Formation, and Oneota Dolomite found between depths of 5,400 and 4,442 
feet from the kelly bushing elevation in WDW No. 2 and extending 
radially 23,500 feet from WDW No. 2. The no-migration demonstration is 
made through use of mathematical simulations which use geological 
information collected at the site or which is found to be appropriate 
for the site and mathematical models which have been proven to be 
capable of simulating natural responses to injection. The simulation is 
calibrated by matching simulator results against observations at the 
site. The exemption was based on the injection through two wells with 
the premise that, at the plume boundary, the effects of injection 
through two or more wells in close proximity are indistinguishable from 
those of injection through a single well. Substitution of WDW No. 3 for 
WDW No. 1 would not require a revision of the modeling, because any 
change in the plume extent will be contained within the conservatively 
delineated boundaries established in 1990.
    In 1990, Cabot used volumetric calculations including dispersivity 
to find that the greatest lateral extent of movement by the waste plume 
will be 17,700 feet. The limit of the waste plume during the life of 
the facility is the distance required for the pH to be increased to 2 
from an original pH of 0.5 due to mixing during advective flow of three 
times the volume of waste injection expected during the wells' 
operational lives. No consideration of reaction of injected waste acid 
and host dolomite which will result in a much more rapid pH 
neutralization was considered. Additional movement of waste 
constituents at hazardous levels for the 10,000-year post operating 
period was determined by calculating the extent of natural ground water 
movement, including buoyancy and dispersion. The total distance of 
travel from the wells' centroid required to increase pH from 0.5 to 2 
with additional movement of 3,300 feet due to natural flow and 2,500 
feet due to buoyancy effects results in a total movement of 23,500 
feet. The lateral extent of migration was shown to be less than 
distances to features which might allow discharge of hazardous waste 
constituents into USDWs.
    The limit of vertical movement was determined by a similar process. 
The lower starting point used to calculate the distance upward to the 
point where dispersion would result in waste dilution 10 times greater 
than that required to increase the waste's pH from 0.5 to 2 was 4,830 
feet, the greatest depth at which the packer of WDW No. 1 could be set 
with no indication of leakage. Long-term vertical movement is primarily 
due to molecular diffusion through 10,000 years. The calculation showed 
that the total vertical distance from the surface to the plume boundary 
is 4,592 feet from the surface. This vertical plume was contained 
within the waste management unit defined for Cabot's two injection 
wells. Therefore, the Agency accepted the demonstration and granted an 
exemption in 1990.
    The petitioner has complied with 40 CFR Secs. 148.20(a), (b), and 
(c) by the demonstration described in the proposal to grant the 
original exemption published in the Federal Register on August 24, 
1990, at 55 FR 34739 et seq. The petitioner has further demonstrated 
the protective nature of land disposal through injection by the 
submission of additional geological and hydrological data on August 16, 
1995. Accordingly, U.S. EPA proposes to reissue the exemption as 
requested.

III. Conditions of Petition Approval

    The existing exemption was granted with conditions. All of the 
conditions attached to the exemption and modifications remain in force 
except Nos. 5 and 6 of the exemption granted on February 4, 1991. 
Condition No. 5 required that an oxygen activation log be run in WDW 
No. 1 in 1991. Condition No. 6 required annual temperature logging of 
WDW No. 1. These conditions will be moot after the plugging of WDW No. 
1. No new conditions are attached to this reissuance of the exemption.

    Dated: November 20, 1995.
Rebecca L. Harvey,
Acting Director, Water Division, Region 5, U.S. Environmental 
Protection Agency.
[FR Doc. 95-29035 Filed 11-27-95; 8:45 am]
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