[Federal Register Volume 60, Number 186 (Tuesday, September 26, 1995)]
[Proposed Rules]
[Pages 49537-49539]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-23840]



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[[Page 49538]]



ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 264, 265, 270, and 271

[FRL-5303-3]


Corrective Action for Solid Waste Management Units (SWMUs) at 
Hazardous Waste Management Facilities

AGENCY: Environmental Protection Agency.

ACTION: Notice of Response to Comments.

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SUMMARY: On June 2, 1994, the Environmental Protection Agency (EPA) 
published a Notice of Data Availability (NODA) and request for comment 
in the Federal Register, which announced the availability of a revised 
draft Regulatory Impact Analysis (RIA) prepared by the Agency for the 
proposed Resource Conservation and Recovery Act (RCRA) requirements for 
corrective action for solid waste management units at hazardous waste 
management facilities. The information included data in support of the 
proposed Subpart S rule relating to corrective action, published on 
July 27, 1990, and the final rule for Corrective Action Management 
Units (CAMUs) and Temporary Units (TUs), promulgated on February 16, 
1993. This notice constitutes a response to comments received on that 
NODA.

ADDRESSES: Copies of the comments may be obtained by calling or 
visiting the RCRA Information Center. The RCRA Information Center is 
located in Room M2616 at EPA Headquarters and is available for viewing 
from 9 a.m. to 4 p.m., Monday through Friday, excluding Federal 
holidays. Requests for obtaining the document by telephone may be made 
by calling (202) 260-9327. Copies cost $0.15 per page.

FOR FURTHER INFORMATION CONTACT: For general information, contact the 
RCRA/Superfund Hotline, Office of Solid Waste, U.S. Environmental 
Protection Agency, 401 M Street, SW, Washington, DC 20460, telephone 
(800) 424-9346; in the Washington, DC metropolitan area the number is 
(703) 412-9810, TDD (703) 412-3323.

SUPPLEMENTARY INFORMATION:

I. July 27, 1990 Proposal

    On July 27, 1990 EPA proposed a comprehensive rule (Subpart S, 55 
FR 30798) specifying corrective action requirements for facilities 
regulated under Subtitle C of the Resource Conservation and Recovery 
Act (RCRA) as amended by the Hazardous and Solid Waste Amendments 
(HWSA) of 1984. The proposed rule was developed to provide both the 
technical (e.g., action levels, investigation aspects, remedy selection 
criteria, etc.) and procedural aspects (e.g., definitions, reporting 
and permitting requirements, etc.) of corrective action. A Regulatory 
Impact Analysis (RIA) to estimate the costs and benefits of the Subpart 
S proposed rule was developed to support the proposed rule. In that 
proposal, the EPA explained that it would continue to refine its 
estimates and make the results available to the public. In the June 2, 
1994 Federal Register Notice of Data Availability and request for 
comments, EPA made available the revised draft Subpart S RIA that 
includes supporting data regarding studies conducted by EPA concerning 
the use of CAMUs in RCRA corrective actions. EPA used these supporting 
data in a rulemaking authorizing the establishment of CAMUs (58 FR 
8658, February 16, 1993). Although the CAMU rulemaking included a 
supplemental notice (57 FR 48195, October 22, 1992) as well as a 
separate RIA and a summary report, some commenters requested additional 
information on the data supporting that analysis. EPA believes the 
summary report provided sufficient detail for purposes of the CAMU 
rulemaking. However, because the results of the CAMU RIA will be 
relevant to the regulatory options analysis in the final Subpart S RIA, 
as well as a related RCRA rulemaking initiative known as the Hazardous 
Waste Identification Rule (HWIR) for contaminated media, a more 
detailed breakdown of the CAMU data was included in the supporting data 
made available through the June 2, 1994 Federal Register notice.
    EPA believes the data made available through the June 2, 1994 
Federal Register notice satisfy the outstanding requests for additional 
information on the data supporting the CAMU rulemaking. To date, EPA 
has received ten (10) sets of public comments on these data. EPA has 
evaluated these comments and believes that none of the issues raised by 
the commenters indicate a need for EPA to re-visit the impact analysis 
done in support of the CAMU rulemaking. However, because of the 
potential relevance of these comments to EPA's ongoing rulemaking 
efforts, EPA will continue to evaluate and respond to comments within 
the context of the Subpart S RIA and HWIR rulemaking for contaminated 
media.

II. Summary of Public Comments

    As of the July 18, 1994 deadline, ten (10) commenters had submitted 
letters with comments regarding the data made available through the 
June 2, 1994 Federal Register notice. A number of commenters stated 
that the Subpart S proposal is likely to be affected by the HWIR 
rulemaking for contaminated media, and recommended that the impact of 
the HWIR rulemaking be reflected in the Subpart S rulemaking. In 
addition, commenters raised a number of issues regarding the 
methodology and assumptions used for the draft RIA. EPA agrees that 
events that have occurred since the Subpart S proposal was issued, 
including the development of HWIR, should be taken into account in the 
Subpart S rulemaking. Because EPA is now considering how to proceed 
with the Subpart S rulemaking, the Agency is not providing a detailed 
response to these comments at this time. However, EPA will take these 
comments into account when deciding whether to finalize or repropose 
portions of the Subpart S proposal.
    One commenter, in addition to addressing the RIA methodology as it 
applies to the Subpart S proposal, also addressed its applicability to 
the final CAMU rule. The commenter first argued that EPA's failure to 
conduct sensitivity analyses on the effects of parameter uncertainty 
undermined many of the draft RIA's conclusions. In response to this 
comment, EPA conducted an analysis in the Draft RIA for the Final 
Rulemaking on Corrective Action for Solid Waste Management Units in 
which OSW identified and evaluated the sources, magnitude, and 
consequences of uncertainty in predictions of chemical concentrations 
and exposures in the multimedia fate and transport modelling component 
of the RIA. The scope of the analysis of uncertainty focused on 
predictions of concentrations and exposures from unremediated sites 
using a Monte Carlo version of MMSOILS (a multimedia contaminant fate, 
transport, and exposure model) at two sample facilities (one facility 
and environmental setting was well characterized, the other was 
limited.) The two sample facilities were subjected to quantitative 
(sensitivity) analyses of the effects of parameter uncertainty on 
chemical concentration, with the Monte Carlo results used to estimate 
the cumulative distribution frequency of the chemical concentration in 
ground water, surface water, air, agricultural and food products, and 
biota. In addition, Monte Carlo parameter sensitivity methods were used 
to evaluate model sensitivity to parameter uncertainty.
    Further, the commenter argued that, because no sensitivity analyses 
were performed on sample selection, facility characterization, 
contaminant releases, remedy selection, remedy effectiveness, human 
health and ecological benefits, averted water use costs, residential 

[[Page 49539]]
property value changes, and cost/ benefit comparisons, results may not 
be reliable in predicting decision-making during actual corrective 
actions. EPA does not believe that this type of analysis was necessary 
here, since the RIA did take account of potential uncertainty. In the 
draft RIA, EPA conducted a stratified random sampling procedure 
developed to maximize the precision of the population estimator in 
extrapolating the sample findings to the corrective action population. 
In addition, EPA used information collected from EPA Regional files and 
state regulatory agency files with regard to facility operations and 
history, environmental setting, SWMU characteristics, extent of 
existing contamination, and potential receptors to substantially 
increase the reliability of the draft RIAs conclusions. All of these 
factors reduce the need for additional uncertainty analysis. Therefore, 
EPA believes that the scope of the uncertainty analysis was adequate 
and further sensitivity analyses were not required. However, EPA will 
continue to assess this issue as the Agency moves forward with the 
Subpart S rulemaking.
    The commenter also argued that the draft RIA's conclusions, which 
are based on the proposed Subpart S rule, do not apply to corrective 
actions performed under the final CAMU rule, which differs from the 
proposal. Another commenter also suggested that the draft RIA should be 
revised to reflect the promulgation of the CAMU rule. The commenters 
are correct that the draft RIA incorporates the proposed CAMU rather 
than the final version. However, as indicated above, EPA in its June 2, 
1994 Federal Register notice made available a more detailed breakdown 
of data supporting the final CAMU RIA so that commenters would have 
additional information on the data supporting the final version of the 
CAMU rule. EPA believes that this supplemental material, along with the 
information provided in the CAMU RIA, provides sufficient support for 
the final rule. The final CAMU rule expanded the CAMU concept from the 
July 27, 1990 proposed rule to increase flexibility in selection of 
more cost-effective remedies, increase treatment of waste and 
contaminated media, and speed implementation of the program. According 
to the supplemental data and analyses, remedy selections based upon the 
more flexible expanded CAMU provisions, using facility-specific data on 
actual contamination (where available) and modelling data to estimate 
the extent of contamination, allow for consolidation of contaminated 
media prior to treatment and result in more treatment of waste that 
otherwise would not be treated.
    The commenter also stated that the remedy selection process was 
flawed because the technical panels did not fairly represent real-world 
facilities and time frames. EPA disagrees; the process contained a 
number of safeguards to assure that it was representative of actual 
decision-making. In order to account for the complexity of the 
decision-making process when simulating the selection of remedies, EPA 
developed an approach that relied on panels of experts to select 
remedies at the sample facilities. In order to capture the interactions 
between EPA and the facility, EPA convened policy and technical expert 
panels. Policy panels were identified and selected by officials in 
EPA's Office of Solid Waste to represent the role of the regulatory 
agency in setting remedial objectives, assess technical information on 
the performance of potential remedies, and make final remedy selection 
decisions. The policy panels consisted of experienced Regional EPA and 
State regulatory staff with expertise in a variety of technical areas 
including geology, engineering, and risk assessment. Technical panels 
consisting of national remediation experts were identified through a 
selective search across many well-recognized firms in the U.S., 
representing the hydrogeology, geology, geochemistry, soil science, 
civil, chemical, or environmental engineering, and chemistry 
disciplines. The technical panels developed the technical remedies for 
each facility based on guidance from the policy panel, then estimated 
the costs of the remedies. Because sample facility scenarios were based 
upon actual facilities, actual owner/operators were not employed in 
determining remedy selections at the sample facilities in order to 
ensure the confidentiality of sample facility deliberations and remedy 
selections determined by the expert panels. However, the qualifications 
of the selected experts made them well-suited to take on the decision-
making role of owner/ operators. Time constraints imposed upon the 
expert panels reflected the simplified decision making process 
specified in the ground rules for the expert panel process as described 
on page 4-4 of the RIA. The CAMU provisions specified five decision 
factors for selecting remedies: long-term reliability and 
effectiveness; reduction of toxicity, mobility, or volume of wastes; 
short-term effectiveness; implementability; and, cost. Agency officials 
were present throughout the expert panel process to resolve specific 
questions concerning the interpretation/applicability of current Agency 
policy and to ensure that remedial objectives were consistent with the 
CAMU provisions. Accordingly, the expert panel process, though somewhat 
simplified compared to the actual decision-making process, involved a 
consideration of relevant factors by qualified experts. As such, it 
adequately represented real-world decisions for purposes of this 
rulemaking.
    Based upon results of the impact analysis done in support of the 
CAMU rulemaking, as well as the above discussion in response to public 
comments, EPA believes it is not necessary to re-visit the regulatory 
impact analysis for the CAMU rulemaking.

    Dated: August 24, 1995.
Elliott P. Laws,
Assistant Administrator, Office of Solid Waste and Emergency Response.
[FR Doc. 95-23840 Filed 9-25-95; 8:45 am]
BILLING CODE 6560-50-P