Hazardous Waste Treatment, Storage, and Disposal Facilities and Hazardous Waste Generators; Organic Air Emission Standards for Tanks, Surface Impoundments, and Containers; Final Rule ENVIRONMENTAL PROTECTION AGENCY

SUMMARY: Under the authority of the Resource Conservation and Recovery

Act (RCRA), as amended, the EPA is promulgating air standards that will

further reduce organic emissions from hazardous waste management

activities. The air standards apply to owners and operators of

hazardous waste treatment, storage, and disposal facilities (TSDF)

subject to RCRA subtitle C permitting requirements and to certain

hazardous waste generators accumulating waste on-site in RCRA permit-

exempt tanks and containers. Under these standards, air emission

controls must be used for tanks, surface impoundments, and containers

in which hazardous waste is placed on or after June 5, 1995 except

under certain conditions specified in the rule. Air emission control

requirements are also added to the RCRA permit terms and provisions

specified for TSDF miscellaneous units. In addition, this action

establishes a new EPA reference test method (Method 25E) to determine

the organic vapor pressure of a waste.

EFFECTIVE DATE: The final rule is effective as of June 5, 1995. The EPA

has specified in the final rule a schedule that establishes the

compliance dates by which different requirements of the rule must be

met. These compliance dates and requirements are explained further

under SUPPLEMENTARY INFORMATION.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of June 5, 1995.

ADDRESSES: Background information document. The background information

document (BID) for the final rule may be obtained from the U.S. EPA

Library (MD-35), Research Triangle Park, North Carolina 27711,

telephone (919) 541-2777. Please refer to ``Hazardous Waste Treatment,

Storage, and Disposal Facilities (TSDF)--Background Information for

Promulgated Organic Air Emission Standards for Tanks, Surface

Impoundments, and Containers'', EPA document number EPA-453/R-94-076b.

This document and the BID are also available on the EPA's Clean-up

Information Bulletin Board (CLU-IN). To access CLU-IN with a modem of

up to 28,800 baud, dial (301) 589-8366. First-time users will be asked

to input some initial registration information. Next, select ``D''

(download) from the main menu. Input the file name ``RCRAAIR1.ZIP'' to

download this notice. Input the file name ``RCRAAIR2.ZIP'' to download

the BID. Follow the on-line instructions to complete the download. More

information about the download procedure is located in Bulletin 104; to

read this type ``B 104'' from the main menu. For additional help with

these instructions, telephone the CLU-IN help line at (301) 589-8368.

Docket. The supporting information used for this rulemaking is

available for public inspection and copying in the RCRA docket. The

RCRA docket numbers pertaining to this rulemaking are F-91-CESP-FFFFF,

F-92-CESA-FFFFF, F-94-CESF-FFFFF, and F-94-CE2A-FFFFF. The RCRA docket

is located at the EPA RCRA Docket Office (5305) in room 2616 of the

U.S. Environmental Protection Agency, 401 M Street SW, Washington, DC

20460.

FOR FURTHER INFORMATION CONTACT:

The RCRA Hotline, toll-free at (800) 424-9346. For further information

on the specific air standards and test method promulgated by this

action, contact Ms. Michele Aston, Emission Standards Division (MD-13),

Office of Air Quality Planning and Standards, U.S. Environmental

Protection Agency, Research Triangle Park, North Carolina 27711,

telephone number (919) 541-2363.

SUPPLEMENTARY INFORMATION: The information presented in this preamble

is organized as follows:

I. Compliance Dates

II. Summary of Rule Changes Since Proposal

A. TSDF Tanks, Surface Impoundments, and Containers

B. TSDF Miscellaneous Units

C. Generator 90-Day Tanks and Containers

D. Other RCRA Regulatory Actions

E. Test Methods

III. Summary of Final Rule Impacts

IV. Background

A. Implementation of RCRA Section 3004(n)

B. Public Participation in Rulemaking

C. Relationship to Other RCRA Standards

D. Relationship to CERCLA Standards

E. Relationship to Clean Air Act Standards

F. Relationship to Nuclear Regulatory Commission Standards

V. Basis for Final Rule

A. New Control Options

B. Control Option Impacts

C. Selection Rationale

VI. Summary of Responses to Comments on Proposed Rule

A. Development of Air Standards Under RCRA

B. Revised Impacts Analysis

C. Container Air Standards

D. Generator 90-Day Tanks and Containers

E. Implementation of RCRA Air Standards

F. Waste Stabilization in Tanks

VII. Requirements of Final Rule

A. TSDF Tank, Surface Impoundment, and Container Requirements

B. TSDF Miscellaneous Unit Requirements

C. 90-Day Tanks' and Containers' Requirements

D. Amendments to Subparts AA and BB Standards

VIII. Implementation of Final Rule

A. Existing Sources

B. New Sources

C. State Authority

IX. Test Methods

A. Method 25D

B. Method 25E

X. Administrative Requirements

A. Paperwork Reduction Act

B. Executive Order 12866 Review

C. Regulatory Flexibility Act

D. Docket

XI. Legal Authority

I. Compliance Dates

The final rule promulgated today establishes additional air

standards for TSDF owners and operators subject to 40 CFR part 264 or

40 CFR part 265. In addition, this rule amends the conditions for

hazardous waste generators accumulating waste on-site in RCRA permit-

exempt tanks and containers pursuant to 40 CFR 262.34(a) to include air

emission control requirements. All of these rule requirements are

effective as of June 5, 1995. All hazardous waste placed in the

affected tanks, surface impoundments, containers, and other affected

units on and after this date must be managed in accordance with the

requirements of the final rule. This includes implementing the required

air emission controls on an affected unit or performing the required

waste determinations and recordkeeping to indicate that the affected

unit is exempted from these air emission control requirements. Under

circumstances when the air emission control equipment required to

comply with the rule cannot be operational at an existing TSDF by June

5, 1995, an implementation schedule for installation of the equipment

must be developed and placed in the facility operating records no later

than June 5, 1995. In such cases, the facility owner or operator must

have all air emission controls required by the final rule in operation

no later than December 8, 1997.

Today's action amends 40 CFR 270.4 to require that owners and

operators of TSDF for which a final permit has been issued by the EPA

prior to June 5, 1995 must comply with the air emission control

requirements for interim-status TSDF under 40 CFR 265 subparts AA, BB,

and CC until the facility's permit is reviewed or reissued by the EPA.

The EPA's rationale for adopting this implementation practice for

today's rulemaking is explained in section VI.E of this preamble.

For tanks in which waste stabilization activities (sometimes

referred to as waste fixation) are performed as of December 6, 1994, be

the effective date of the final rules will December 6, 1995. As of the

extended effective date for stabilization tanks, each TSDF owner or

operator and each hazardous waste generator subject to the final rules

must either install and operate the specified air emission control

requirements on all affected tanks used for stabilization, or begin

performing the specified waste determinations and recordkeeping to

indicate that a stabilization tank is exempted from these requirements.

Under circumstances where required air emission control equipment

cannot be operational on stabilization tanks by December 6, 1995, an

implementation schedule for installation of the required air emission

controls must be developed and placed in the facility operating records

no later than December 6, 1995.

In such cases, for stabilization tanks, the facility must have all

air emission controls required by the final rules in operation no later

than June 8, 1998.

II. Summary of Rule Changes Since Proposal

The EPA proposed the rule on July 22, 1991 (refer to 56 FR 33491).

Based on public comments received by the EPA at proposal as well as the

EPA's evaluation of additional information obtained after proposal,

certain requirements of the rulemaking have been changed from those

proposed. The major changes affect provisions establishing the rule

applicability, the procedures for determining the average volatile

organic concentration of a waste, and the air emission control

requirements for containers. In addition, the EPA has made many changes

to the specific regulatory text to clarify the EPA's intent in the

application and implementation of the rule requirements. The

substantive changes to the rulemaking since proposal are summarized

below. A summary of the requirements of the rule as promulgated is

presented in section VII of this preamble.

A. TSDF Tanks, Surface Impoundments, and Containers

A new subpart CC is added by today's action to both 40 CFR parts

264 and 265. Subpart CC under 40 CFR part 264 applies to owners and

operators of permitted TSDF while subpart CC under 40 CFR part 265

applies to owners and operators of interim-status TSDF. All changes

since proposal to subpart CC in 40 CFR part 264 and to subpart CC in 40

CFR part 265 are identical with the exception of changes to the rule

reporting requirements. There are no reporting requirements under 40

CFR 265 subpart CC for owners and operators of interim-status TSDF.

Hereafter for convenience in this preamble, the term ``subpart CC

standards'' is used collectively to refer to both subpart CC in 40 CFR

part 264 and subpart CC in 40 CFR part 265.

The compliance time for the subpart CC standards has been revised

since proposal to allow up to an additional 30 months after June 5,

1995 to install and begin operation of air emission control equipment

required by the rule provided that the owner or operator develops and

places in the facility operating records by this date an implementation

schedule for installation of the equipment. Compliance dates and

implementation requirements for the final rule are explained in

sections I and VIII of this preamble.

1. Applicability

The applicability of the subpart CC standards has been revised

since proposal to specifically exempt from the rule certain tanks

surface impoundments, and containers in which the owner or operator has

stopped adding hazardous waste. The subpart CC standards do not apply

to a tank, surface impoundment, or container that meets either of the

following conditions:

(1) No hazardous waste is added to the waste management unit on or

after June 5, 1995 (see generally 55 FR 39409, September 27, 1990); or

(2) Addition to hazardous waste to the waste management unit is

stopped and the owner or operator has begun implementing or completed

closure pursuant to an approved closure plan.

In addition, the applicability of the subpart CC standards has been

changed such that the rule is not applicable to any container having a

design capacity less than 0.1 m\3\ (approximately 26 gallons)

regardless of the organic content of the hazardous waste handled in the

container. In response to comments on the proposed rule, the EPA

reviewed the types of small containers commonly used to accumulate and

transfer hazardous waste. Considering the small quantity of hazardous

waste handled in a sample collection vial, safety can, disposal can,

and other types of small containers and the short periods of time that

the waste normally remains in one of these containers, the EPA

concluded that existing rules for containers having a design capacity

less than 0.1 m\3\ are sufficient to protect human health and the

environment.

Finally, the EPA has decided to temporarily defer application of

the subpart CC standards to tanks, surface impoundments, and containers

managing hazardous wastes under certain special circumstances. For now,

the EPA is deferring application of the subpart CC standards to waste

management units that are used solely to treat or store hazardous

wastes generated on-site from remedial activities required under RCRA

corrective action or CERCLA response authorities (or similar State

remediation authorities). Also, the EPA is deferring application of the

subpart CC standards to waste management units that are used solely to

manage radioactive mixed wastes. The EPA's rationale for these

deferrals is explained in section VIII.A.1 of this preamble.

2. General Standards

For each tank, surface impoundment, or container to which the

subpart CC standards apply (referred to here as an ``affected unit''),

the owner or operator is required to use the air emission controls

specified in the rule except when the hazardous waste placed in an

affected unit meets certain conditions. As explained in the following

paragraphs, the conditions under which an affected unit is exempted

from the air emission control requirements of the subpart CC standards

have been revised since proposal.

a. Waste volatile organic concentration exemption. Under the final

subpart CC standards, an affected unit is exempt from the air emission

control requirements of the rule if all hazardous waste placed in the

unit is determined to have an average volatile organic concentration

less than 100 parts per million by weight (ppmw) based on the organic

composition of the hazardous waste at the point of waste origination.

This waste volatile organic concentration limit incorporates several

revisions that have been made by the EPA since proposal.

First, the format for the limit has been changed to be the average

volatile organic concentration of the hazardous waste on a mass-

weighted basis during normal operating conditions for the source or

process generating the waste (in contrast to the proposed format of the

maximum volatile organic concentration for the hazardous waste never to

be exceeded). Averaging periods up to 1 year in duration are allowed

for each individual waste stream under the final rule. The procedures

for determining the average volatile organic concentration of a waste

are explained further under ``Waste Determination Procedures'' in this

section and in section VII.A.3 of this preamble.

Second, determination of the volatile organic concentration of the

waste under the final rule is based on the organic composition of the

waste at the ``point of waste origination'' (instead of the ``point of

waste generation'' as proposed). The ``point of waste origination'' is

defined in the final rule with respect to the point where the TSDF

owner or operator first has possession of a hazardous waste. When the

TSDF owner or operator is the generator of the hazardous waste, the

``point of waste origination'' means the point where a solid waste

produced by a system, process, or waste management unit is determined

to be a hazardous waste as defined in 40 CFR part 261. In this case,

this term is being used in a similar manner to the use of the term

``point of generation'' in waste operations air standards established

under authority of the Clean Air Act in 40 CFR parts 60, 61, and 63 of

this chapter. When neither the TSDF owner nor operator is the generator

of the hazardous waste, the ``point of waste origination'' means the

point where the owner or operator accepts delivery or takes possession

of the hazardous waste.

Finally, the EPA revised the impact analysis used for this

rulemaking after proposal to incorporate additional TSDF industry data.

An opportunity for public comment on this analysis was provided by the

EPA (refer to sections III.B and VI.B of this preamble). Based on the

revised analysis results, the EPA selected a new value for the volatile

organic concentration limit. Section V.C of this preamble presents the

rationale for the selection of the control option used as the basis for

the final rule.

b. Treated hazardous waste exemption. Under the subpart CC

standards, each affected tank, surface impoundment, and container that

manages hazardous waste having an average volatile organic

concentration equal to or greater than 100 ppmw, as determined by the

procedures specified in the rule, is required to use air emission

controls in accordance with the rule requirements. The owner or

operator must install and operate the specified air emission controls

on every affected tank, surface impoundment, and container used in the

waste management sequence from the point of waste origination (as

applies to the specific hazardous waste stream) through the point where

the organics in the waste are removed or destroyed by a process in

accordance with the requirements of the rule. If a particular hazardous

waste is not treated to meet these requirements, then all affected

units at the TSDF used in the waste management sequence for this

hazardous waste are required to use the air emission controls specified

by the subpart CC standards.

If the hazardous waste is treated to remove or destroy the organics

in the waste by a process that meets or exceeds a minimum level of

performance as specified in the rule, then affected units at the TSDF

operated downstream of the treatment process in the waste management

sequence for this hazardous waste are not required to use the air

emission controls specified by the subpart CC standards. It is

important to emphasize that tanks, surface impoundments, and containers

(subject to the rule) in which the treatment process is conducted are

required to use the applicable air emission controls specified by the

subpart CC standards with the exception of certain tanks and surface

impoundments used for active biological treatment of hazardous waste

and achieving the performance requirements specified in the rule (this

exception is explained further in section VII.A.4 of this preamble).

The conditions under which a treated hazardous waste no longer is

required to be managed in affected units using air emission controls

under the subpart CC standards have been revised and expanded since

proposal to include many alternatives from which an owner or operator

can choose one with which to comply. The final subpart CC standards

allow an owner or operator to use any type of treatment process that

can continuously achieve one of the specified sets of performance

conditions. These conditions have been changed to include:

(1) The average volatile organic concentration of the hazardous

waste exiting the process is less than 100 ppmw (except for certain

site-specific situations where multiple hazardous waste streams are

treated by a single process in which case a volatile organic

concentration limit for the waste exiting the process is established by

the rule procedures at a value lower than 100 ppmw);

(2) The organic reduction efficiency for a process treating

multiple hazardous waste streams is equal to or greater than 95

percent, and the average volatile organic concentration of the

hazardous waste exiting the treatment process is less than 50 ppmw; or

(3) The actual organic mass removal rate for the process is greater

than the required mass removal rate established for the process. The

alternative treatment process performance requirements specified in the

final subpart CC standards are discussed further in section VII.A.2 of

this preamble.

The proposed explicit exemption for hazardous wastes complying with

the land disposal restriction (LDR) treatment standards is not included

in the final subpart CC standards. The EPA concluded that the expanded

number of alternatives for treated hazardous waste and other provisions

added to the final rule provide a reasonable regulatory mechanism by

which a TSDF owner or operator can determine whether a hazardous waste

complying with the LDR treatment standards is exempted from being

managed in accordance with the air emission control requirements of the

subpart CC standards.

3. Waste Determination Procedures

As already noted, the procedures that a TSDF owner or operator may

use to determine the volatile organic concentration of a hazardous

waste have been revised for the final subpart CC standards. For a case

when direct measurement is chosen for determining the volatile organic

concentration of a hazardous waste, the proposed statistical

calculation procedure using Method 25D results is not included in the

final subpart CC standards. Instead, procedures are specified in the

final rule to compute the mass-weighted average volatile organic

concentration of a hazardous waste using Method 25D results for waste

generated as part of a continuous process and for waste generated as

part of a batch process. Under circumstances when the same batch

process is performed repeatedly but not necessarily continuously, the

final rule allows the owner or operator to determine the average

volatile organic concentration of the waste from this process by

averaging results for one or more representative waste batches

generated by the process. In all cases, a sufficient number of waste

samples for analysis (with a minimum of four samples) must be collected

to be representative of the normal range of the operating conditions

for the source or process generating the hazardous waste. Normal

operating conditions for the source or process generating the waste

include cyclic process operations such as startup and shutdown. Process

malfunctions, maintenance activities, or equipment cleaning are not

considered to be normal operating conditions for the purpose of

determining the average volatile organic concentration of a waste.

These waste determination procedures are discussed further in section

VII.A.3 of this preamble.

The proposed explicit requirements for determining the volatile

organic concentration of a hazardous waste using information in a waste

certification notice prepared by the waste generator are not included

in the final rule. Instead, for hazardous waste that is not generated

by the TSDF owner or operator (i.e., waste shipped to the TSDF from

off-site sources under different ownership), the final rule allows the

TSDF owner or operator to determine the waste volatile organic

concentration by either testing the waste when he or she accepts

delivery of the hazardous waste or using appropriate information about

the waste composition that is prepared by the generator of the waste.

The generator prepared information can be included in manifests,

shipping papers, or waste certification notices accompanying the waste

shipment, as agreed upon between the waste generator and the TSDF owner

or operator.

4. Tank Standards

Several changes to the tank standards have been made since

proposal. An exemption from the tank standards has been added for those

affected tanks used for biological treatment of a hazardous waste in

accordance with requirements specified in the rule. Changes have been

made to clarify the regulatory text regarding the tank cover design and

operating requirements. Also, the conditions have been clarified that

must be met for a particular tank to use a fixed-roof type cover

without any additional controls in accordance with the subpart CC

standards. Finally, provisions have been added to the rule to address

those special situations in which emergency venting of the tank or the

air emission controls installed on the tank is necessary for safety.

5. Surface Impoundment Standards

Changes to the surface impoundments standards have been made to be

consistent with the changes to the tank standards as applicable.

6. Container Standards

Several changes have been made to the container standards since

proposal in addition to limiting the applicability of the subpart CC

standards to containers having a design capacity equal to or greater

than 0.1 m\3\. The air emission control requirements for affected

containers have been revised to provide several air emission control

alternatives from which an owner or operator may choose one with which

to comply. For containers having a design capacity less than or equal

to 0.46 m\3\ (approximately 119 gallons), an owner or operator may

place the hazardous waste in drums that meet U.S. Department of

Transportation (DOT) specifications under 49 CFR part 178 without any

additional testing, inspection, or monitoring requirements. An owner or

operator is also allowed under the final rule to place the hazardous

waste in tank trucks and tank railcars that are annually demonstrated

to be vapor tight using Method 27 in 40 CFR part 60, appendix A without

any additional testing, inspection, or monitoring requirements.

The requirements for waste transfer operations for containers have

been revised under the final subpart CC standards. Submerged-fill of

hazardous waste that is loaded into containers by pumping is required

only when transferring the waste into containers having a design

capacity greater than 0.46 m\3\. Submerged fill of the waste is not

required when filling smaller size containers such as 55-gallon drums.

The air emission control requirements for owners and operators

treating hazardous waste in open containers have been revised. Whenever

it is necessary for the container to be open during the treatment

process, the container is required to be located in an enclosure

connected to a closed-vent system with an operating organic emission

control device. The final subpart CC standards include specific

enclosure design and operation requirements which allow the enclosure

to have permanent openings for worker access.

Finally, the container standards have been revised to be consistent

with the safety venting provisions added to the tank and surface

impoundment standards.

7. Closed-Vent System and Control Device Standards

The design and operating requirements for closed-vent systems and

control devices have been changed to be consistent with those

requirements already applicable to TSDF owners and operators under

subpart AA in 40 CFR parts 264 and 265. The subpart AA standards have

been in effect since 1990 and establish RCRA air standards to control

organic emissions from process vents on certain types of hazardous

waste treatment units.

8. Inspection and Monitoring Requirements

The inspection and monitoring requirements under the subpart CC

standards have been revised since proposal. The requirements for

inspection and monitoring of closed-vent systems and control devices

have been changed to be identical to the inspection and monitoring

requirements under subpart AA in 40 CFR parts 264 and 265. The required

interval for the visual inspection of covers installed on tanks,

surface impoundments, and certain containers has been changed to once

every 6 months. After the initial cover inspection and monitoring for

detectable organic emissions is completed, the owner or operator is

only required to inspect and monitor those cover openings that have

been opened (i.e., have not continuously remained in a closed, sealed

position) since the last visual inspection and monitoring. Special

inspection and monitoring provisions have been added for cover fittings

that are unsafe or difficult, as defined in the rule, for facility

personnel to inspect and monitor.

The subpart CC standards have been changed to allow leak repair on

tank and surface impoundment covers to be delayed beyond 15 calendar

days if both of the following conditions occur: (1) Repair of the leak

requires first emptying the contents of the tank or surface

impoundment; and (2) temporary removal of the tank or surface

impoundment from service will result in the unscheduled cessation of

production from the process unit, or operation of the waste management

unit, that is generating the hazardous waste managed in the tank or

surface impoundment. Repair of a leak must be performed at the next

time the process, system, or waste management unit that is generating

the hazardous waste managed in the tank or surface impoundment stops

operation for any reason.

9. Recordkeeping Requirements

The subpart CC standards have been changed to require cover design

documentation only for floating roof-type tank covers, surface

impoundment covers, and enclosures used for control of air emissions

from containers. Also, the recordkeeping requirements have been revised

as appropriate to address the changes to the final rule described

previously in this section of the preamble.

10. Reporting Requirements

The reporting requirements in the subpart CC standards are the same

as proposed with one exception. The time interval within which TSDF

owners and operators subject to the subpart CC standards under 40 CFR

part 264 must report to the Regional Administrator all circumstances

resulting in noncompliance with the applicable conditions has been

changed to within 15 calendar days of the time that an owner or

operator becomes aware of the circumstances.

B. TSDF Miscellaneous Units

Today's action amends 40 CFR 264.601 by adding to the permit terms

and provisions required for RCRA permitting of a miscellaneous unit the

appropriate air emission control requirements in 40 CFR part 264,

subparts AA, BB, and CC. This amendment is the same as proposed.

C. Generator 90-Day Tanks and Containers

The conditions with which a hazardous waste generator must comply,

pursuant to 40 CFR 262.34(a), to exempt tanks and containers

accumulating hazardous waste on-site for no more than 90 days from the

RCRA subtitle C permitting requirements are amended by today's action

to include compliance with the air emission control requirements of 40

CFR part 265, subparts AA, BB, and CC. This amendment is the same as

proposed.

D. Other RCRA Regulatory Actions

The EPA proposed several amendments to existing RCRA air standards.

One amendment proposed adding requirements for the management of spent

carbon removed from a carbon adsorption system to the closed-vent

system and control device standards under 40 CFR part 264, subparts AA

and BB, and 40 CFR part 265, subparts AA and BB. The final amendment

has been revised to allow the owner or operator the additional option

of burning the spent carbon in a boiler or industrial furnace that is

permitted under subpart H of 40 CFR part 266. A second amendment

promulgated today updates the leak detection monitoring provisions

under 40 CFR part 264, subparts AA and BB, and 40 CFR part 265,

subparts AA and BB for closed-vent systems to be consistent with other

air standards recently promulgated by the EPA. Under this amendment,

annual leak detection monitoring is not required for those closed-vent

system components which continuously operate in vacuum service or those

closed-vent system joints, seams, or other connections that are

permanently or semi-permanently sealed (e.g., a welded joint between

two sections of metal pipe, a bolted and gasketed pipe flange).

E. Test Methods

As part of this rulemaking, the EPA proposed two new reference test

methods (Method 25D and Method 25E) to be added to 40 CFR part 60,

Appendix A. Method 25D is a test method for the determination of the

volatile organic concentration of waste materials. Since proposal, the

EPA decided it is also appropriate to use method 25D to implement other

EPA air standards being developed under authority of the Clean Air Act.

The promulgation of some of these other air standards prior to today's

action required the EPA to promulgate Method 25D in a separate

rulemaking (refer to 59 FR 19402, April 22, 1994). Comments and

responses relevant to Method 25D for this rulemaking are in the BID for

the final rule and in the dockets pertaining to this rulemaking.

Method 25E is being promulgated today. Method 25E is the test

method for determining the organic vapor pressure of wastes. The

sampling requirements for Method 25E have been revised since proposal

to provide for sampling of the waste in a tank.

III. Summary of Final Rule Impacts

The EPA estimates that implementation of the subpart CC standards

will reduce nationwide organic emissions from TSDF tanks, surface

impoundments, and containers by approximately 970,000 Mg/yr. In

addition, the EPA estimates that nationwide organic emissions from 90-

day tanks and containers will be reduced by approximately 73,000 Mg/yr.

Control of organic air emissions addresses many air quality

problems including ambient ozone formation, adverse human health

effects from inhalation of air toxics, and, to a lesser extent,

depletion of stratospheric ozone. Ambient ozone concentrations exceed

the National Ambient Air Quality Standards (NAAQS) in many metropolitan

areas throughout the United States. Thus, the rule promulgated today

will contribute to progress in attaining the NAAQS for ozone in

nonattainment areas and also in preventing significant deterioration of

the air quality in those areas of the United States currently in

attainment with the NAAQS for ozone.

Today's action will also significantly reduce the risk to the

public of contracting cancer posed by exposure to toxic constituents

contained in the organic emissions from hazardous waste management

activities. The cancer risk to the entire exposed population nationwide

(i.e., annual cancer incidence) from exposure to organic emissions from

TSDF is estimated by the EPA to be reduced from approximately 48 cases

per year to a level of 2 cases per year. Annual cancer incidence as a

result of exposure to organic emissions from 90-day tanks and

containers is estimated by the EPA to be reduced from approximately

four cases per year to less than one case per year.

Maximum individual risk (MIR) is a measure of the added probability

of a person contracting cancer if exposed continuously over a 70-year

period to the highest annual average ambient concentration of the air

toxics emitted from a TSDF site. There are approximately 2,300 TSDF

locations in the United States. The MIR for all but approximately 20 of

these facilities is estimated by the EPA to be reduced by

implementation of the subpart CC standards to a level that is less than

1 x 10\4\. The target MIR levels historically used by the

EPA for other promulgated RCRA standards range from 1 x

10\4\ to 1 x 10\6\. Because the MIR values

for a few TSDF are estimated to remain higher than the historical RCRA

target, the EPA is continuing to evaluate the waste management

practices and the individual chemical compounds composing the organic

emissions at these TSDF. Following this evaluation, the EPA will

determine what other actions are necessary to attain the health-based

goals of RCRA section 3004(n). The omnibus permitting authority in

section 3005(c)(3) can be invoked to supplement or add to the

requirements in today's rule, should the rule be determined to be

insufficient to assure protection of human health and the environment

at a particular facility.

The total nationwide capital investment cost to TSDF owners and

operators to implement the subpart CC standards is estimated by the EPA

to be approximately $290 million. The total nationwide annual cost for

these standards is estimated to be approximately $110 million per year.

The total nationwide capital costs to hazardous waste generators of

installing the required air emission controls on 90-day tanks and

containers is estimated by the EPA to be approximately $23 million.

Total nationwide annual cost for the 90-day tank and container controls

is estimated to be approximately $7 million.

The EPA concludes that the rule promulgated today will not have a

significant economic impact on hazardous waste generators or TSDF

owners and operators. Prices for commercial hazardous waste management

services are estimated by the EPA to increase by less than 1 percent on

a nationwide annualized basis. The quantity of hazardous waste handled

by commercial hazardous waste management companies is projected to be

reduced by less than 1 percent on a nationwide annualized basis. Few,

if any, facility closures are anticipated. Job losses in the hazardous

waste industry are estimated to be less than 1.5 percent. Furthermore,

this impact on employment does not reflect positive employment effects

on industries producing the air emission control equipment that will be

used to comply with the rule. No significant impacts are expected on

small businesses.

IV. Background

A. Implementation of RCRA Section 3004(n)

The Hazardous and Solid Waste Amendments of 1984 added section

3004(n) to RCRA. Section 3004(n) directs the EPA to promulgate

regulations for the monitoring and control of air emissions from TSDF

as may be necessary to protect human health and the environment. The

EPA completed the first phase of its regulatory development program to

implement this Congressional directive with the promulgation of RCRA

air standards that control organic emissions vented from certain

hazardous waste treatment processes (i.e., distillation, fractionation,

thin-film evaporation, solvent extraction, steam stripping, and air

stripping) as well as from leaks in certain ancillary equipment used

for hazardous waste management processes (55 FR 25454, June 21, 1990).

Today's action completes the second phase of the EPA's regulatory

development program with the promulgation of RCRA air standards for

tanks, surface impoundments, containers, and miscellaneous units

operated at TSDF. This rulemaking also adds air emission control

requirements for certain hazardous waste generators accumulating waste

on-site in RCRA permit-exempt tanks and containers.

As described at proposal (56 FR 33496, July 22, 1991), the EPA

decided in both the first and second phases to develop standards that

control organic emissions as a class (as opposed to constituent-by-

constituent). Implementation of these nationwide standards will achieve

significant organic emission and cancer risk reductions. However, the

EPA estimates the cancer risk at a few TSDF after implementation of

these nationwide standards to remain at a level that is higher than the

range of target risk levels for other promulgated RCRA standards (refer

to section V.C of this preamble.) The third phase of this regulatory

development program is to determine what other actions are necessary to

attain the health-based goals of RCRA section 3004(n). To make this

determination, the EPA is evaluating hazardous waste operations at

those individual TSDF estimated to have MIR values greater than the

historical RCRA target MIR levels.

B. Public Participation in Rulemaking

The EPA is promulgating today's final rule after careful

consideration of public comments on the proposed rule (56 FR 33491,

July 22, 1991). The preamble to the proposed rule discussed the

availability of the background information document (BID) pertaining to

the health effects of organic emissions from hazardous waste TSDF using

tanks, surface impoundments, and containers. The EPA mailed copies of

the Federal Register notice and the BID for the proposed rule to

industry representatives, environmental groups, and State and Federal

agencies.

The EPA solicited comments from the public at the time of proposal

and provided a 90-day comment period, from July 22, 1991 to October 21,

1991, for the public to prepare and submit written comments on the

proposed rule. In addition, the EPA provided the opportunity for a

public hearing to allow interested persons to present oral comments to

the EPA concerning the proposed rule. However, no one requested that

the EPA hold a public hearing on the proposed rule. The EPA did receive

written comments from more than 80 companies, industrial trade

associations, environmental groups, and State and Federal agencies. The

BID for the final rule summarizes all of the comments on the proposed

rule and presents the EPA's response to each of the comments. Section

VI of this preamble presents responses to selected major comments.

Following the EPA's review of public comments received on the

proposed rule, the EPA revised the impact analysis used for its final

determination regarding today's rulemaking. This analysis used

additional TSDF industry data obtained by the EPA. The EPA provided an

opportunity for public comment on the additional TSDF industry data

used for the impact modeling revisions. A Federal Register Notice of

Data Availability (57 FR 43171, September 18, 1992) listed these

additional data. The EPA also made the data available for public

inspection at the EPA RCRA Docket Office. A 30-day comment period, from

September 18, 1992 to October 19, 1992, provided the public the

opportunity to comment on the additional data. The EPA received

comments on the additional data from one industrial trade association.

Section VI.B of this preamble presents a summary of these comments.

C. Relationship to Other RCRA Standards

1. RCRA Rules for TSDF Owners and Operators

Today's action establishes organic air emission control

requirements for TSDF tanks, surface impoundments, and certain

containers. Other types of waste management units operated at TSDF may

be subject to these air emission control requirements as follows.

a. Miscellaneous units. Under RCRA in 40 CFR 260.10, the EPA

defines a ``miscellaneous unit'' as a hazardous waste management unit

where waste is treated, stored, or disposed of that is not a container,

tank, surface impoundment, wastepile, land treatment unit, landfill,

incinerator, boiler, industrial furnace, underground injection well

with appropriate technical standards under 40 CFR part 146, or a unit

eligible for a research, development, and demonstration permit under 40

CFR 270.65. The EPA has established provisions under 40 CFR part 264,

subpart X to allow TSDF owners and operators to obtain permits to

operate miscellaneous units. The EPA permits miscellaneous units on a

case-by-case basis with terms and provisions as needed to protect

public health and the environment through generic performance standards

specified in 40 CFR 264.601.

Today's rule amends Sec. 264.601 to state that the air emission

controls required by the standards under 40 CFR 264 subparts AA, BB,

and CC are among the ``appropriate'' controls a permit writer may

require for a miscellaneous unit ``to ensure protection of human health

and the environment.'' Applicability of today's rule to miscellaneous

units is discussed further in Section VII.B of this preamble.

b. Land disposal restrictions. The RCRA LDR treatment standards

under 40 CFR part 268 require TSDF owners and operators to treat

hazardous waste to reduce the toxicity or mobility of specific

constituents in the waste before the TSDF owner or operator can place

the waste in a land disposal unit. Under certain conditions, the EPA

may grant a TSDF owner or operator permission to land dispose a

hazardous waste that does not meet the LDR treatment standards in a

particular land treatment unit, landfill, wastepile, or surface

impoundment. This action is referred to as the ``no migration''

variance. To obtain a ``no migration'' variance, a TSDF owner or

operator must demonstrate in a petition to the EPA that, with a

reasonable degree of certainty, there will be no migration of hazardous

constituents from the disposal unit for as long as the waste remains

hazardous.

On August 11, 1992, the EPA proposed its interpretation of the term

``no migration'', the procedures and substantive requirements for

submitting to the EPA a petition to demonstrate ``no migration'' from a

land disposal unit, and the EPA's criteria for evaluating the petitions

(57 FR 35940). This proposal includes amending 40 CFR 268.6 to add as a

condition for receiving a no migration variance that the applicant

demonstrate that the subject land disposal unit complies with the

applicable air emission standards the EPA has developed under 40 CFR

parts 264 and 265.

c. Corrective action requirements. The EPA is temporarily deferring

applicability of the subpart CC standards to any tank, surface

impoundment, or container which is used solely for on-site treatment or

storage of hazardous waste that is generated as the result of

implementing remedial activities required under the RCRA corrective

action authorities of 3004(u), 3004(v) or 3008(h). The EPA's rationale

for this temporary deferral is explained in section VII.A.1 of this

preamble.

2. RCRA Rules for Hazardous Waste Generators

Hazardous waste generators who accumulate waste on-site in

containers or tanks for short periods of time can elect to be exempted

from RCRA subtitle C permitting requirements provided that a generator

complies with provisions specified in 40 CFR 262.34. The EPA allows a

generator who generates 1,000 kilograms or more of hazardous waste per

month to accumulate the hazardous waste on-site for up to 90 days in

tanks and containers without a permit provided the generator complies

with certain conditions specified in 40 CFR 262.34(a). These conditions

include compliance with the requirements of 40 CFR part 265, subpart I

when the waste is accumulated in a container and 40 CFR part 265,

subpart J when the waste is accumulate in a tank. Tanks and containers

used to accumulate hazardous waste on-site for 90 days or less pursuant

to the conditions of 40 CFR 262.34(a) are hereafter referred to in this

preamble as ``90-day tanks and containers.''

The rule promulgated today only amends the RCRA permit exemption

requirements for generators operating 90-day tanks and containers. This

action does not affect the existing RCRA permit exemption requirements

for generators operating tanks and containers for on-site accumulation

of hazardous waste in accordance with the provisions of 40 CFR 262.34

(d) or (e). Applicability of today's rule to 90-day tanks and

containers is discussed further in Section VI.D of this preamble.

3. RCRA Rules for Hazardous Waste Transporters

Regulations in 40 CFR part 263 establish standards that apply to

persons transporting hazardous waste within the United States if the

transportation requires a manifest under 40 CFR part 262. Today's

action does not change the RCRA rules under 40 CFR part 263. However,

the air standards promulgated today may indirectly affect transporters

accepting certain organic-containing hazardous wastes from TSDF owners

and operators. The final subpart CC standards require that TSDF owners

and operators only load these hazardous wastes into containers

(including tank truck, railcars, and roll-off boxes) that use air

emission controls as specified in the rule. Consequently, to continue

accepting hazardous waste from a TSDF owner or operator, in some cases,

transporters may need to ensure that their containers meet the subpart

CC standards.

D. Relationship to CERCLA Standards

The Comprehensive Environmental Response, Compensation, and

Liability Act (CERCLA), authorizes the EPA to undertake removal and

remedial actions to clean up hazardous substance releases. Under

CERCLA, on-site remedial actions are required to comply with the

requirement of Federal and more stringent State environmental laws that

are applicable or relevant and appropriate (ARAR) to the remedial

action unless certain statutory waivers apply. In addition, the

National Oil and Hazardous Substances Contingency Plan (NCP) provides

that removal actions shall attain ARAR to the extent practicable

considering the exigencies of the situation. [40 CFR 300.415(i)]. As

explained in section VII.A.1 of this preamble, the EPA has decided to

temporarily defer application of the subpart CC standards to tanks,

containers and surface impoundments which are being used to treat or

store hazardous wastes containing organics generated on-site from

remedial activities required under RCRA corrective action or CERCLA

response authorities, or similar State remediation authorities,

provided that the wastes are managed in units that do not also manage

other hazardous waste containing organics. However, after the temporary

deferral has been lifted, today's rules may be considered an ARAR for

certain types of remedial and removal actions.

A requirement under a Federal or State environmental law may be

either ``applicable'' or ``relevant and appropriate,'' but not both, to

a remedial or removal action conducted at a CERCLA site. An ARAR is

identified on a site-specific basis in a two-part analysis that

considers first, whether a given requirement is applicable; then, if it

is not applicable, whether it is nevertheless both relevant and

appropriate. ``Applicable'' requirements as defined in the NCP are

those that specifically address a hazardous substance, pollutant,

contaminant, remedial action, location, or other circumstances found at

a CERCLA site. [40 CFR 300.415(i)]. ``Relevant and appropriate''

requirements are those that, while not ``applicable'' at a CERCLA site,

address problems or situations sufficiently similar to those

encountered at the CERCLA site that their use is well suited to the

particular site. [40 CFR 300.415(i)].

Some waste management activities used for remedial and removal

actions of hazardous organic substances require the use of tanks,

surface impoundments, and containers. For example, a TSDF may treat

hazardous organic liquids and surface water contaminated with hazardous

organic waste on site using destruction, detoxification, or organic

removal processes that occur in tanks or surface impoundments. The

facility may perform on-site solvent washing of soils contaminated with

hazardous organic sludges in a tank or container. At a TSDF, hazardous

waste in leaking drums may be repacked in new containers for treatment

and disposal at another site.

Once today's deferral is lifted, the air emission control

requirements of the subpart CC standards are likely to be

``applicable'' to on-site remedial and removal actions that use tanks,

surface impoundments, and containers to manage substances exhibiting

characteristics or listed under RCRA as hazardous waste and having an

average volatile organic concentration equal to or greater than 100

ppmw. In other cases, the standards may be ``relevant and

appropriate''; this determination must be made on a site specific

basis.

On the other hand, the subpart CC standards do not specify control

requirements for wastepiles, landfills, and land treatment units that

manage hazardous wastes at TSDF. Therefore, the standards are not

likely to be ``applicable'' to excavation, capping of wastes, land

treatment, land farming, in situ treatment activities, and other

activities involving wastepiles and landfills at CERCLA sites. Although

in most cases the EPA does not expect the subpart CC standards to be

``relevant and appropriate'' to these types of units at CERCLA sites,

remedial and removal actions performed in wastepiles may in some cases

be similar in nature and scale to the waste management activities

performed in surface impoundments; and waste stabilization may involve

the basic process and air emission mechanism regardless of whether the

mixing of the waste and binder is conducted in a tank, surface

impoundment, container, wastepile, landfill, or land treatment unit.

Thus, in some cases the subpart CC standards may be ``relevant and

appropriate'' for such actions; this determination must be made on a

site specific basis.

E. Relationship to Clean Air Act Standards

Section 112 of the Clean Air Act (CAA) regulates stationary sources

of hazardous air pollutants (HAP). This section was comprehensively

amended under Title III of the 1990 Amendments to the CAA. Under the

amended CAA section 112(b), Congress listed 189 chemicals, compounds,

or groups of chemicals as HAP. The EPA is directed by the CAA to

regulate HAP emissions from stationary sources by establishing national

emission standards for hazardous air pollutants (NESHAP).

The 1990 Amendments to the CAA required the EPA to develop and

publish a list of source categories that emit HAP for which NESHAP will

be developed. The EPA published its initial list of NESHAP source

categories on July 16, 1992 (refer to 57 FR 31576). Many industrial

sectors that may manage hazardous wastes are listed as specific NESHAP

source categories. Consequently, facilities at which hazardous wastes

are managed may be subject to both NESHAP and the RCRA air standards

under 40 CFR part 264 and 265. At these facilities, some waste

management units would be subject to either air emission control

requirements under the NESHAP or the air emission control requirements

under the RCRA air standards. However, in certain situations, some

waste management units would be subject to air emission control

requirements under both sets of rules.

The CAA requires that the requirements of standards developed under

the Act be consistent, but avoid duplication, with requirements of

standards developed under RCRA. Consequently, the EPA is taking into

account the air standards promulgated under RCRA section 3004(n) in

determining the requirements for NESHAP affecting air emission sources

at which hazardous waste could be managed.

F. Relationship to Nuclear Regulatory Commission Standards

Radioactive mixed wastes are wastes that contain radioactive

materials as well as materials listed or identified as hazardous under

RCRA. Radioactive mixed wastes must be managed in accordance with RCRA

regulations, in addition, these wastes also are subject to standards

administered by the Nuclear Regulatory Commission (NRC) under the

Atomic Energy Act and Nuclear Waste Policy Act of 1982 that address the

safe handling and disposal of radioactive waste.

The EPA has previously stated its general position that the

management of radioactive mixed waste at TSDF is subject to regulation

under subtitle C of RCRA (51 FR 24504, July 3, 1986; 53 FR 37045,

September 23, 1988). In developing the RCRA standards applicable to

radioactive mixed wastes, the EPA considers the management practices

required for these wastes to avoid inconsistencies between the EPA's

hazardous waste management requirements and the NRC's radioactive waste

management requirements. Furthermore, RCRA section 1006(a) precludes

any solid or hazardous waste regulation by the EPA or a State that is

``inconsistent'' with the requirements of the Atomic Energy Act. Thus,

in a case where the regulatory requirements for radioactive mixed waste

are conflicting, the NRC requirement takes precedence over the RCRA

requirement. Because of the potential that air emission control

equipment required by the subpart CC standards promulgated today may

conflict with certain radioactive waste management requirements under

NRC standards, the EPA has decided to temporarily defer application of

the subpart CC standards to tanks, containers, and surface impoundments

which are being used solely to manage radioactive mixed wastes. This

deferral is discussed further in section VII.A.1 of this preamble.

V. Basis for Final Rule

A. New Control Options

The EPA developed a national impacts model specific to the air

emission sources affected by this rulemaking to compare the human

health and environmental protection provided by the different air

emission control options. Following proposal of the rule, the EPA

revised this model to incorporate new information obtained by the EPA

and to address public comments on the impact analysis methodology

received at proposal. Section VI.B of this preamble presents a further

discussion of the impact analysis revisions.

At proposal, the EPA gave notice that consideration of new results

from revisions to the national impacts analysis could lead to selection

of any one of the control options considered at proposal or possibly a

new control option (56 FR 33516). Upon reviewing preliminary results

for the revised national impacts model, the EPA decided to expand the

number of control options considered for the final rule.

The EPA first performed a screening evaluation by using the revised

national impacts model to estimate the nationwide organic emission and

cancer incidence reductions for the original five control option

configurations described at proposal (56 FR 33512), plus nine new

control option configurations. The EPA included a summary of the

impacts model results for these 14 control options in the information

listed in the Notice of Data Availability (57 FR 43171) and made

available for public inspection at the EPA RCRA Docket Office (refer to

RCRA docket entry number F-92-CESA-00018).

The EPA used the screening evaluation results to select a final

group of control options selected for further analysis. The EPA

eliminated a control option from further consideration if another one

of the control options was estimated to provide the same level of

nationwide organic emission or cancer incidence reduction but at a

lower cost. This is the same control option selection approach the EPA

used at proposal.

Based on the screening evaluation results, the EPA selected four

control options for further analysis. In addition to the control option

used as the basis for the proposed rule, the EPA also analyzed

``baseline'' impacts. These ``baseline'' impacts represent the

estimated nationwide organic emissions and other impacts that would

occur in the absence of implementing any of the control options. The

final group of five control options (designated Options A through E)

differ by the value used for the volatile organic concentration limit

and the type of air emission controls used for surface impoundments.

Option A requires air emission controls on all TSDF tanks, surface

impoundments, and containers managing hazardous waste with any

detectable volatile organic concentration as determined at the point

where the waste is generated (i.e., a volatile organic concentration

action level of 0 ppmw). Under Option A, tanks use a cover vented to a

control device except for tanks handling certain hazardous wastes.

Tanks in which the organic vapor pressure of the hazardous waste in the

tank is less than 10.4 kPa (approximately 1.5 psi) may use a cover

without additional controls. All surface impoundments use a cover

vented to a control device. Containers use cover and submerged fill for

loading hazardous wastes into the containers.

Option B requires air emission controls only on those TSDF tanks,

surface impoundments, and containers used to manage hazardous wastes

having a volatile organic concentration at the point where the waste is

generated equal to or greater than 100 ppmw. The control requirements

are the same as described for Option A with one exception; surface

impoundments used for storage of hazardous waste and surface

impoundments used for treatment of hazardous waste by a process not

requiring aeration or agitation of the waste require covers only.

Option C requires air emission controls only on those TSDF tanks,

surface impoundments, and containers used to manage hazardous wastes

having a volatile organic concentration at the point where the waste is

generated greater than 500 ppmw. The air emission control requirements

are the same as described for Option B. Option C is the same control

option selected as the basis for the proposed rule.

Option D requires air emission controls only on those TSDF tanks,

surface impoundments, and containers used to manage hazardous wastes

having a volatile organic concentration at the point where the waste is

generated greater than 1,500 ppmw. The air emission control

requirements are the same as described for Options B and C.

Option E requires air emission controls only on those TSDF tanks,

surface impoundments, and containers used to manage hazardous wastes

having a volatile organic concentration at the point where the waste is

generated greater than 3,000 ppmw. The air emission control

requirements are the same as described for Options B, C, and D.

B. Control Option Impacts

The EPA estimated nationwide organic emission and cancer risk

reductions that would be achieved if air standards were implemented for

each of the five control options. The ``baseline'' nationwide organic

emissions from TSDF are estimated to be approximately 1 million Mg/yr.

The estimated nationwide TSDF organic emissions assuming implementation

of the individual control options are 30,000 Mg/yr for Option A, 41,000

Mg/yr for Option B, 48,000 Mg/yr for Option C, 51,000 Mg/yr for Option

D, and 90,000 Mg/yr for Option E.

To assess the risk of contracting cancer posed by exposure to

organic emissions from TSDF, the EPA used two measures of health risk:

Annual cancer incidence and maximum individual risk (MIR). The annual

cancer incidence parameter represents an estimate of population risk

and, as such, measures the aggregate risk to all people in the United

States estimated to be living within the vicinity of TSDF. The MIR

parameter represents the potential of air emissions from a particular

source to cause cancer in the most exposed hypothetical individual

under the assumptions used in the risk and exposure assessments.

Estimation of these health risk parameters requires the EPA to make

several critical assumptions regarding the TSDF plant configurations

and operating practices, the composition of wastes managed at these

TSDF, the cancer potency of the organics contained in these wastes, the

emission of these organics to the atmosphere from TSDF sources, and the

exposure of people living near TSDF to these air toxic emissions. The

complex interrelationship of the various assumptions prevents the EPA

from definitively characterizing the estimated health risk parameter

values as being overestimates or underestimates.

The EPA estimated annual cancer incidence for baseline and the five

control options using the EPA's Human Exposure Model (HEM), the site-

specific cancer risk factors, and TSDF industry profile data bases.

This risk value is based on the estimated number of excess cancers

occurring in the nationwide population after a lifetime exposure

(defined to be 70 years). For statistical convenience, the EPA divided

the aggregate risk by 70 and expressed the risk as cancer incidence per

year. The information provided in RCRA docket entry numbers F-92-CESA-

S00014 and S00015 describes the estimation methodology in more detail.

The EPA estimates baseline nationwide annual cancer incidence from

exposure to TSDF organic emissions to be 48 cases per year. The

estimated nationwide TSDF cancer incidences, assuming implementation of

the individual control options, are two cases per year for Option A,

two cases per year for Option B, four cases per year for Option C, five

cases per year for Option D, and nine cases per year for Option E.

The EPA uses the MIR parameter for relative comparisons of

pollutants, emission sources, and control alternatives. For the impact

analysis, the EPA estimated the MIR parameter assuming that exposure of

the individual to the ambient air toxic concentrations occurs for 24

hours per day for a lifetime of 70 years. The EPA realizes that this is

a conservative assumption since most people do not spend their entire

lives at one location. However, it is completely possible for an

individual to live in the same place for his or her entire life.

Furthermore, other uncertainties in the analysis could lead to

underestimating the risk. For example, the actual exposed

subpopulations (such as children or asthmatics) may be more sensitive

to the emitted air toxics than the reference adult male for which the

unit risk factor extrapolations are based. In addition, the analysis

does not address potential indirect exposure pathways to humans, or

potential harm to environmental receptors.

The MIR parameter reflects the added probability that a person

would contract cancer if exposed continuously over a 70-year period to

the highest annual average ambient concentration of the air toxics

emitted from a TSDF. Baseline MIR from exposure to TSDF organic

emissions is estimated to be 3 x 10\2\. The estimated MIR's, assuming

implementation of the individual control options, are: 4 x 10-3

for Option A, 4 x 10-3 for Option B, 2 x 10-2 for Option

C, 3 x 10-2 for Option D, and 3 x 10-2 for Option E.

These MIR values apply only to the very few TSDF, of the approximately

2,300 TSDF operating in the United States, that are estimated to have

the potential to cause the highest risk. The values do not represent

actuarially measured risks nor do they apply to all TSDF in the United

States. The EPA is not attempting to estimate any specific individual's

potential of developing cancer. Finally, the EPA is not interpreting

any of these estimates as indicators of the absolute risks of

contracting cancer. Rather, the purpose of this cancer risk assessment,

both for incidence and MIR, is to compare relative differences among

the individual control options (i.e., ``degree'' of human health

protection).

In addition to estimating organic emissions and cancer risk

parameters, the national impacts model provides an estimate of the

total nationwide capital costs and annual costs to the TSDF owners and

operators to install and operate the air emission controls specified by

each control option. For these nationwide cost estimates, the EPA

assumed that, at every TSDF location, treatment of all hazardous wastes

to remove or destroy the organics in the waste occurs as the last step

prior to disposal of the waste. In actuality, the EPA expects that, at

many TSDF, the owner or operator (after becoming aware of the air

standards) will elect to treat waste at an earlier step in the waste

management sequence. By treating organics in compliance with one of the

waste treatment alternatives provided in final rule, the owner or

operator could avoid the costs of installing and operating control

equipment on the downstream tanks, surface impoundments, and

containers.

Capital investment cost represents the cost to TSDF owners and

operators to purchase and install the air emission control equipment.

The estimated nationwide capital costs in 1986 dollars to implement the

control options are: $520 million for Option A, $290 million for Option

B, $240 million for Option C, $200 million for Option D, and $140

million for Option E. Annual cost represents the total cost to TSDF

owners and operators each year to pay for operating and maintaining the

air emission controls as well as to repay the capital investment for

the air emission controls. The capital recovery was estimated using an

interest rate of 10 percent applied over a period ranging from 10 to 20

years depending on the expected service life for each type of air

emission control equipment. The estimated nationwide annual costs to

implement the control options are: $190 million/yr for Option A, $110

million/yr for Option B, $90 million/yr for Option C, $80 million/yr

for Option D, and $60 million/yr for Option E.

C. Selection Rationale

From Options A through E, the EPA selected one control option to

serve as the basis for today's final rule. The EPA applied the same

decision rationale used at proposal for this rulemaking (56 FR 33515-

33516, July 22, 1991) as well as for RCRA air standards promulgated

under subparts AA and BB to 40 CFR parts 264 and 265 (refer to 55 FR

25470, June 21, 1990). This decision rationale requires the EPA to

select, whenever possible, the level of control that provides an

acceptable degree of protection of human health and the environment. If

no control option is available to achieve acceptable levels of

protection, the EPA's approach historically has considered cost under

RCRA only for equally protective control options.

All five of the control options considered for the final rule are

estimated to achieve similar levels of substantial reductions in

nationwide organic emissions from TSDF. The nationwide organic emission

reductions for the control options are estimated to be approximately

970,000 Mg/yr for Option A, 960,000 Mg/yr for Option B, 950,000 Mg/yr

for Option C, 950,000 Mg/yr for Option D, and 910,000 Mg/yr for Option

E.

Both Options A and B are estimated to achieve the lowest cancer MIR

and greatest reduction in annual cancer incidence of the five options.

However, none of the control options reduces MIR to the target cancer

risk levels used for other promulgated RCRA standards, which have been

in the range of 1 x 10-4 to 1 x 10-6. The estimated MIR is an

order-of-magnitude higher for Options C, D, and E (2 x 10-2 for

Option C, 3 x 10-2 for Options C and D) compared to Options A and

B (4 x 10-3). Annual cancer incidence reductions estimated for

Option C (44 cases per year), Option D (43 cases per year), and Option

E (39 cases per year) are lower than the annual cancer incidence

reductions estimated for Options A and B (46 cases per year).

On the basis of the estimated annual cancer incidence and MIR, the

EPA concluded that Options A and B are more protective of human health

than Options C, D, or E. Therefore, the EPA eliminated Options C, D,

and E from further consideration as the basis for the final rule.

Both Options A and B are estimated to achieve the same level of

cancer risk reduction (MIR to 4 x 103 and annual

cancer incidence to two cases per year). Therefore, the EPA concluded

that Options A and B are equally protective of human health and the

environment (to the extent ascertainable by this modelling

methodology). Historically under RCRA, the EPA has considered control

option costs only to select between options estimated to achieve

equivalent levels of protection. Therefore, to select between Options A

and B, the EPA compared the estimated costs to implement each of the

control options. Option B requires the use of air emission controls

only on those TSDF tanks, surface impoundments, and containers used to

manage hazardous wastes with a volatile organic concentration at the

point where the waste is generated equal to or greater than 100 ppmw.

Because TSDF owners and operators would need to install and operate air

emission controls on fewer TSDF tanks, surface impoundments, and

containers, Option B would be less expensive for the TSDF industry to

implement than Option A. Therefore, the EPA selected Option B as the

basis for the final rule.

While Option B does not achieve the target MIR levels historically

used for other promulgated RCRA rules, Option B does achieve

substantial reductions in cancer risk. The annual cancer incidence is

estimated to be reduced by greater than 95 percent from the baseline

value. Furthermore, the MIR for most of the 2,300 TSDF nationwide are

estimated to achieve the target MIR levels. To address the remaining

cancer risk at TSDF after implementation of the air standards

promulgated today, the EPA is further evaluating the waste management

practices and the specific chemical compounds composing the organic

emissions from those individual TSDF for which the MIR values are

estimated to be greater than the historical RCRA target MIR levels.

Following this evaluation, the EPA will determine what other actions,

such as the use of section 3005(c)(3) omnibus permitting authority or

additional rulemaking, are necessary to attain the health-based goals

of RCRA section 3004(n).

VI. Summary of Responses to Comments on Proposed Rule

All of the comments on the proposed rule and the EPA's response to

each of these comments is presented in ``Hazardous Waste Treatment,

Storage, and Disposal Facilities (TSDF)--Background Information for

Promulgated Organic Air Emission Standards for Tanks, Surface

Impoundments, and Containers'', EPA document number EPA-453/R-94-076b

(to obtain a copy of this document refer to the ADDRESSES section of

this preamble). The EPA's responses to topics addressed by many of the

commenters are summarized below.

A. Development of Air Standards Under RCRA

Comment: Many comments were received regarding the extent to which

the congressional directive of RCRA section 3004(n) should be

implemented using air standards established by the EPA under Clean Air

Act (CAA) authority. Commenters stated the position that protection of

human health and the environment from TSDF air emissions is most

appropriately, effectively, and efficiently addressed by developing air

standards under the CAA authority. Therefore, commenters believe that

the EPA should make the determination that the requirements of RCRA

section 3004(n) are best fulfilled by deferring to air standards

established under CAA authority. Commenters stated that the air

standards proposed by the EPA under authority of RCRA section 3004(n)

are:

(1) Not needed because existing CAA programs adequately address the

control of TSDF organic emissions;

(2) Duplicative or contradictory of new programs now being

implemented by the EPA to control hazardous air pollutants as directed

by section 112 of the CAA;

(3) Not in compliance with RCRA section 1006(b) regarding

duplication or contradiction of CAA requirements;

(4) Inconsistent with CAA programs that establish ozone precursor

control requirements depending on the national ambient air quality

standards attainment status of the region in which a source is located;

(5) Inconsistent with the EPA's pollution prevention policy;

(6) Contrary to the EPA's ``cluster concept'' of examining and

coordinating regulations addressing the same emission source to

minimize duplicative or contradictory requirements; and

(7) Difficult to administer and enforce because, traditionally, one

State regulatory agency administers rules regulating air emissions

while another administers rules regulating hazardous waste management.

Response: The Hazardous and Solid Waste Amendments to RCRA added

section 3004(n), which directs the EPA to ``* * * promulgate

regulations for the monitoring and control of air emissions from

hazardous waste treatment, storage, and disposal facilities, including

but not limited to open tanks, surface impoundments, and landfills, as

may be necessary to protect human health and the environment.'' The EPA

considers the most appropriate, effective, and efficient way to fulfill

this congressional mandate is to develop air standards for TSDF that

are implemented under the existing RCRA subtitle C permitting program

already in place for these facilities. However, the EPA disagrees with

one commenter's assertion that, in establishing these RCRA air

standards, the EPA cannot consider the impact of air standards

promulgated or currently being developed under other statutory

authorities such as the CAA. On the contrary, RCRA section 1006(b)

requires the EPA to coordinate its regulations under RCRA statutes and

to avoid duplication, to the maximum extent practicable, with

appropriate provisions of the CAA.

The EPA disagrees that the requirements of RCRA section 3004(n) are

best fulfilled by deferring to air standards established under CAA

authority. There is no indication that Congress intended for air

standards to be issued only within the authority granted to the EPA by

the CAA. If this was the case, then Congress would not have amended

RCRA section 3004(n) under HSWA after Congress had already authorized

the EPA to control air emissions under the CAA. Refer to S. Rep. No.

284, 98th Cong. 1st sess. 63. Thus, both RCRA and the CAA authorize the

EPA to control air emissions from TSDF.

Although historically many standards promulgated by the EPA under

authority of RCRA have addressed the prevention of soil and water

contamination from improper management of hazardous waste, the EPA is

not limited by RCRA to promulgating standards only for certain media

(e.g., surface waters, groundwater, and soils). Indeed, RCRA section

3004(n) specifically directs the EPA to issue regulations controlling

air emissions from TSDF as necessary to protect human health and the

environment.

The selection of TSDF air emission sources for control by

establishing air standards under RCRA section 3004(n) is based on

controlling those TSDF air emission sources determined by the EPA to

have significant toxic and ozone precursor emission potential but for

which emission control is not adequately addressed by other standards

promulgated by the EPA such as NESHAP and NSPS established under the

CAA. At proposal, the EPA concluded that additional air emission

control requirements for TSDF tanks, surface impoundments, and

containers are needed. This decision was based on the EPA's

determination that existing and future Federal standards under the CAA

and State air standards do not adequately address the control of TSDF

organic air emissions.

As previous described in section III.E of this preamble, CAA

section 112 has been amended by Congress since RCRA section 3004(n) was

enacted. Section 112 of the CAA as amended requires the EPA to identify

major sources and area sources of HAP emissions and to develop NESHAP

for these sources. To date for this air standards development program,

the EPA has either promulgated or proposed several NESHAP that may

apply to some hazardous waste management activities at TSDF. However,

in general, these NESHAP added requirements to address HAP emissions

from certain waste and material recovery operations that are not

subject to or exempted from regulation under the RCRA air standards in

40 CFR parts 264 and 265. Thus, the NESHAP and other air standards

being developed under CAA are not intended to duplicate the RCRA air

standards, but instead to integrate with the RCRA air standards to

create a comprehensive air program for addressing organic air emissions

from all waste and related material recovery operations.

For example, on-site wastewater treatment operations at synthetic

organic chemicals manufacturing industry (SOCMI) facilities are

regulated under the hazardous organic NESHAP (``the HON'') promulgated

on April 22, 1994 (see 59 FR 19402). At many of these facilities, the

hazardous wastewaters generated by process units and resulting

wastewater treatment sludges are managed in tank systems that are

exempted from RCRA permitting requirements under provisions in 40 CFR

264.1(g)(6) or 40 CFR 265.1(c)(10). Thus, the air emission control

requirements under the HON, in most cases, affect wastewater treatment

tanks not subject to the RCRA air standards.

A second example is the recently proposed NESHAP for off-site waste

and recovery operations (59 FR 51913, October 13, 1994). This NESHAP

would apply to owners and operators of facilities, with certain

exceptions, that manage wastes or recoverable materials which have been

generated off-site at another facility and contain specific organic

HAP. The rule would apply to operations managing solid wastes as

defined under RCRA (hazardous and nonhazardous wastes) as well as

operations handling recovered materials excluded from the RCRA

definition of solid waste (e.g., recycled materials containing organic

HAP, used oil reprocessed for sale as a fuel). As a result, certain

off-site waste and recovery operations with organic HAP emissions, but

exempted from regulation under the RCRA air standards, would be

required to use air emission controls under this NESHAP.

In contrast to the NESHAP now being developed under CAA section

112, the EPA has already achieved progress toward full implementation

of RCRA section 3004(n), which requires a ``cradle to grave'' approach

to hazardous waste management that addresses protection of air, water,

and groundwater. Air standards have been promulgated for TSDF treatment

process vents (subpart AA in 40 CFR parts 264 and 265) and for TSDF

process equipment leaks (subpart BB in 40 CFR parts 264 and 265) in

addition to the development of these air standards for TSDF tanks,

surface impoundments, and containers. There is no benefit to delaying

implementation of air standards for TSDF tanks, containers, and surface

impoundments to a future rulemaking under amended CAA section 112 when

the EPA can proceed now with the promulgation of effective air

standards under RCRA section 3004(n) for these air emission sources.

The RCRA air standards adopted today do comply with RCRA section

1006(b). This section requires that the air standards be consistent

with and not duplicative of CAA standards. Although RCRA section

1006(b) requires some accommodation with existing regulatory standards,

it ``does not permit the substantive standards of RCRA to be

compromised.'' Chemical Waste Management v. EPA, 976 F.2d at 23 (D.C.

Cir. 1992). It is obviously reasonable for the EPA to view the RCRA

section 3004(n) mandate as a standard which cannot (or at least need

not) be compromised. Similarly, the CAA Amendments of 1990 require that

air standards developed under the CAA be consistent with RCRA rules. To

conform with the dual RCRA and CAA requirements that standards be

consistent, the air standards developed under RCRA section 3004(n) do

not duplicate or contradict existing NESHAP or NSPS.

The EPA is fully aware that at many facilities where hazardous

wastes are managed, the RCRA air standards under 40 CFR part 264 and

265 as well as NESHAP and NSPS for specific source categories may be

applicable to a particular TSDF. Certain testing, monitoring,

inspection, recordkeeping, and other requirements under the RCRA air

standards may be similar to or duplicative of requirements under the

applicable NESHAP or NSPS. In many cases at a TSDF, individual waste

operations will be subject to either the air emission control

requirements under the RCRA air standards or the air emission control

requirements under the applicable NESHAP or NSPS. Thus, it is necessary

to include testing, monitoring, inspection, recordkeeping, and other

implementation requirements in each rule to assure compliance with and

enforcement of the rule. However, in certain situations, some

individual waste operations at a TSDF could be subject to air emission

control requirements under both the RCRA air standards as well as a

NESHAP or NSPS. In such cases, the EPA believes it is unnecessary for

owners and operators of these waste management units to conduct

duplicative waste testing, keep duplicate sets of records, or perform

other duplicative actions to demonstrate compliance with both sets of

rules. Therefore, to be consistent with RCRA section 1006(b) to the

maximum extent practicable, the EPA is coordinating the testing,

recordkeeping, reporting, and other implementation activities required

under the RCRA air standards and related rules developed under the CAA.

The EPA has requested public comment in a related proposed NESHAP

rulemkaing (the off-site waste and recovery operations NESHAP, see 59

FR 51919, October 13, 1994) on how the applicable requirements included

in the RCRA air standards should be incorporated into CAA rules being

developed by the EPA for waste and recovery operations that will allow

owners and operators subject to both sets of rules to demonstrate

compliance with all applicable rules without having to repeat the

duplicative requirements.

Nevertheless, RCRA section 1006(b) cannot be used to ignore key

elements of RCRA; see Chemical Waste Management v. EPA, 976 F.2d at 23.

In this case, Congress has indicated that TSDF air emissions need to be

controlled on the RCRA timetable, not that of the CAA. Deferring

totally to the CAA would vitiate this key RCRA requirement. [See also

RCRA section 3004(q) and CAA section 112(n)(7) in which Congress

indicated that pendency of CAA air standards for RCRA units does not

vitiate RCRA requirements.]

The EPA's approach to developing air standards for TSDF under RCRA

is consistent with CAA programs to achieve attainment and to maintain

national ambient air quality standards (NAAQS). The NAAQS specify

limits to pollutant concentrations in the ambient air to protect public

health and welfare. A NAAQS has been established for ozone. Ambient

ozone concentrations in many metropolitan regions of the United States

exceed the NAAQS. Organic emissions from TSDF as well as other sources

react photochemically with other chemical compounds in the atmosphere

to form ozone. The CAA requires that States develop and the EPA approve

air emission control plans called ``State implementation plans''

(SIP's). For those regions within a State that are in nonattainment

with the NAAQS for ozone, the SIP specifies the standards and other

control measures to be implemented by the State to attain the NAAQS.

However, the CAA requires the EPA not only to implement programs to

attain the NAAQS in nonattainment areas but also to maintain, and

prevent significant deterioration of, the air quality in those areas of

the Nation currently in attainment with the NAAQS. Consequently, in

addition to the CAA control programs to address specific regional NAAQS

attainment problems, the EPA also develops under the CAA authority

minimum national emission standards applicable to stationary sources

independent of whether the source is located in a NAAQS attainment or

nonattainment area. The EPA considers the subpart CC standards to be

reasonable national standards needed to control emissions of air toxics

as well as to attain and maintain NAAQS for ozone.

The subpart CC standards are consistent with the EPA's pollution

prevention policy. Pollution prevention involves reducing the quantity

of pollution produced for a given quantity of product prior to

recycling, treatment, or control of emissions. Activities defined as

source reduction measures in the Pollution Prevention Act include

technology modifications, process and procedure modifications,

reformulation or redesign of products, and substitution of raw

materials. A decrease in production alone does not qualify as pollution

prevention. Under the subpart CC standards, a TSDF owner or operator is

not required to manage a hazardous waste in a tank, surface

impoundment, or container using the specified air emission controls in

cases when the owner or operator determines that the organic content of

all hazardous waste placed in the unit meets certain conditions

specified in the rule. Thus, the subpart CC standards encourage

pollution prevention by providing an incentive to generators to

initiate source reduction measures that will reduce the concentration

of organics in a hazardous waste.

The development of TSDF air standards under RCRA is not contrary to

the EPA's ``cluster'' approach of examining and coordinating

regulations addressing the same emission source to minimize duplicative

or contradictory requirements. The different EPA Offices responsible

for implementing RCRA and CAA requirements are coordinating the

development of this rulemaking to ensure that subpart CC standards are

compatible with other rules and programs applicable to TSDF owners and

operators.

The air emission control requirements for tanks under the subpart

CC standards incorporate provisions of NSPS that were promulgated under

the authority of the CAA and apply to storage tanks constructed or

modified after July 23, 1984, that contain volatile organic liquids (40

CFR part 60, subpart Kb). Therefore, air emission controls already in

use on a TSDF tank in compliance with 40 CFR part 60, subpart Kb will

comply with air emission control requirements of the subpart CC

standards. Also, the subpart CC standards for closed-vent systems and

control devices cross reference the requirements for closed-vent

systems and control devices promulgated under subpart AA in 40 CFR

parts 264 and 265. The subpart AA requirements are consistent with the

requirements for closed-vent systems and control devices under several

CAA air standards.

The implementation of air standards under RCRA does not create

difficulties in administration and enforcement of the rules by State

regulatory agencies. Although many existing RCRA standards focus on

preventing the contamination of soil and water, other existing RCRA

regulations regulate air emissions from some TSDF sources (e.g.,

combustion of hazardous waste is regulated under 40 CFR part 264,

subpart O for hazardous waste incinerators and under 40 CFR part 266

subpart H for boilers and industrial furnaces). Air emissions are also

sometimes addressed through the EPA's omnibus permitting authority

under RCRA section 3005(c)(3). States authorized by the EPA administer

and enforce the requirements of RCRA rules in lieu of the EPA

administering the rules in that State. The EPA is aware that, in many

States, one State agency administers air standards while another State

agency administers rules regulating the management of hazardous waste

in the State. Similarly, it is common for yet another State agency to

administer water quality rules. The experience of authorized States

administrating existing RCRA rules shows that responsibility for

administrating these rules can be delegated to a separate State agency

without impeding the administration and enforcement of non-RCRA air and

water rules by other State agencies.

B. Revised Impacts Analysis

Comment: The commenter on the Notice of Data Availability (NDA) (57

FR 43171, September 18, 1992) supports the EPA's use of the updated

waste data base for the national impacts analysis and the EPA's changes

to the emission models for biological treatment processes. In addition,

the commenter agrees with the EPA's conclusion that many surface

impoundments reported in the waste data base to be managing waste at

TSDF have been or are being replaced with tanks to comply with the RCRA

land disposal restriction and other regulations. However, the commenter

believes that the EPA's assumption that 75 percent of the total waste

quantity reported in the waste data base to be managed in surface

impoundments is now managed in tanks is too low. The commenter agrees

with the EPA's revised approach in the impact analysis of using site-

specific cancer risk factors to estimate cancer risk due to exposure to

TSDF emissions. However, the commenter states that some of the specific

assumptions made by the EPA for the risk analysis are implausible

(e.g., assuming exposure of the individual for 70 years) and the

analysis should be conducted in accordance with the EPA's own Exposure

Assessment Guidelines. Finally, the commenter does not believe that any

MIR estimate is necessary to assess the need for and effectiveness of

the rule.

Response: For the national impacts analysis, the EPA believes that

75 percent is a reasonable assumption for the amount of waste that is

converted from surface impoundment to tank management. As discussed

further in the BID for the final rule, the EPA selected the 75 percent

value based on information obtained by the EPA from a telephone survey

of owners and operators of large TSDF and from TSDF site visits as well

as information provided to the EPA by several TSDF owners and operators

in comments on the proposed rule. The EPA did not find nor receive any

additional information from the commenter that justifies increasing the

percentage of waste converted from surface impoundment to tank

management.

The cancer risk impact analysis for this rulemaking was conducted

in accordance with the EPA's Exposure Assessment Guidelines. With

regard to the 70 year lifetime assumption used in the impact analysis,

the EPA believes 70 years to be conservative, but plausible. The EPA

did however conduct a second risk assessment assuming a 33 year

exposure scenario (95 percentile). Using this assumption reduced risk

estimates by one-half, but did not change the decision to control these

facilities, nor the choice of control options. Furthermore, the risk

assessment conducted here was for the purpose of determining relative

differences in risk estimates between the control options. For this

application, the exposure scenario would not matter; the results, i.e.,

the relative differences in risk estimates, would not change.

The EPA holds that the assumptions used to determine the MIR are,

as with the 70 year exposure scenario, conservative, but plausible, and

result in a reasonable overall estimate of risk. In addition, while the

EPA acknowledges the uncertainties associated with the MIR, such

uncertainties cancel out when the risk assessment is used to discern

relative risk, as in this case. Thus the EPA believes that the use of

the MIR is an appropriate tool to apply in the impact analysis for this

rulemaking to both estimate risk and to discern differences between

risk estimates associated with the various control options.

C. Container Air Standards

Comment: Many commenters disagree with the EPA's decision to

require air emission controls for containers under the subpart CC

standards. One group of commenters argues that the organic emission

potential from TSDF containers does not warrant the application of

additional controls beyond those already required by existing RCRA

standards. A second group of commenters contends that TSDF containers

should not be subject to this rulemaking because the EPA analysis does

not show organic emissions from TSDF containers to be a significant

emission source warranting controls.

Response: The EPA maintains that the management of organic-

containing wastes in containers at TSDF is a potentially significant

source of organic emissions that is not adequately regulated by

existing regulations. Control requirements for containers under the

subpart CC standards are needed to:

(1) Ensure that containers used for storage of organic-containing

waste use covers effective for organic emission control;

(2) Control organic emissions from treatment of organic-containing

wastes in containers by waste stabilization and other processes; and

(3) Prevent circumvention of the containment and control strategy

that serves as a key component of the integrated approach to

implementing RCRA section 3004(n).

The EPA disagrees with the commenters' conclusion that existing

regulations are sufficient to control organic emissions from containers

used to manage hazardous waste at TSDF. Existing RCRA regulations under

40 CFR 264.173 require containers used to store hazardous waste at TSDF

to be closed except when necessary to add or remove waste. This

requirement for closed containers during storage does not specify

organic air emission controls for these covers. Furthermore, no RCRA

requirements exist that address organic emissions associated with other

container operations such as hazardous waste transfer or treatment in

open containers.

The EPA also disagrees with the commenters' conclusion that

managing hazardous wastes in containers is not a significant potential

source of organic air emissions. The baseline analysis to estimate

nationwide TSDF organic emissions by waste management category is not

the only factor that the EPA considered in assessing the organic

emission potential of containers. The revised nationwide baseline

emissions from storage of hazardous waste in TSDF containers is

estimated to be approximately 5,000 Mg/yr. However, this emission

estimate for containers does not include organic emissions from

hazardous waste treatment in containers. As described in the BID for

the final rule, the EPA estimates the total organic emissions from

waste fixation operations performed in containers to be approximately

11,000 Mg/yr. Information obtained by the EPA representatives during

site visits to TSDF conducting waste fixation operations indicates that

use of containers for waste fixation continues to be a common industry

practice. Thus, treatment of hazardous waste in containers is a large

potential source of organic emissions that is not regulated by the

existing RCRA regulations.

The air emission control requirements for the subpart CC standards

are based on applying a containment and control strategy to TSDF tanks,

surface impoundments, and containers from generation of the waste

through treatment of the waste to remove or destroy the organics in the

waste. Requiring control of only TSDF tanks and surface impoundments

but not containers creates a significant potential organic emission

source if large quantities of hazardous waste currently stored or

treated in tanks required to use air emission controls under subpart CC

standards are transferred to containers not using air emission

controls. This would allow organics in the hazardous waste managed in

uncontrolled containers to escape to the atmosphere prior to treatment

and, thus, reduce the effectiveness of the containment and control

approach.

D. Generator 90-Day Tanks and Containers

Comment: Many commenters disagree with the EPA's decision to apply

the proposed air standards to 90-day tanks and containers for the

following reasons:

(1) The EPA is not authorized under RCRA section 3004(n), or under

other provision, to extend the air standards to 90-day tanks and

containers;

(2) The proposed rule failed to cite authority to extend the

requirements to 90-day tanks and containers, in violation of section

553(b)(2) of the Administrative Procedures Act;

(3) If the EPA imposes air emission controls on generators, this

must be accomplished pursuant to the pre-HSWA authorization process and

thus should not become effective in authorized States until enacted and

implemented as State law; and

(4) Application of air emission control requirements to 90-day

tanks and containers impermissibly interferes with manufacturing

processes.

Response: The EPA disagrees with each of these comments. The

provisions of 40 CFR 262.34 (promulgated under the authority of RCRA

section 2002, 3001-3005, and 3007) allow generators to accumulate

hazardous waste in tanks and containers for specified time periods

without obtaining RCRA permits, provided the generator meets certain

conditions. Amending these conditions is a valid exercise of the EPA's

authority under RCRA section 3004(n).

The intent of including the provisions of 40 CFR 262.34 in the RCRA

requirements for hazardous waste generators is to obtain a reasonable

balance between the Congress's desire not to interfere with the

generator's manufacturing or production processes with the need to

provide adequate protection of human health and the environment (45 FR

12730, February 26, 1980). Thus, 40 CFR 262.34 does not provide a

hazardous waste generator with a complete exemption from all RCRA

requirements. On the contrary, it incorporates most of the relevant

tank and container requirements under 40 CFR part 265 and requires

compliance with these standards as a condition for maintaining RCRA

permit-exempt status [refer to 40 CFR 262.34(a)(1)]. The intent of

these provisions is not to exclude 90-day tanks and containers from

future technical TSDF requirements. Therefore, it is wholly appropriate

for the EPA to update the technical requirements for tanks and

containers that serve as the basis for the RCRA permit exemption. The

EPA has already done so, for example, when tank standards were amended

in 1986.

Although 90-day tanks and containers are not required to be

permitted under RCRA subtitle C, the EPA rejects the commenters' narrow

reading of RCRA section 3004(n) as limiting the EPA's authority to

extend the requirements to these units. Section 3004(n) of RCRA

requires the EPA to promulgate standards for the control of air

emissions from ``hazardous waste treatment, storage, and disposal

facilities.'' The EPA does not agree that RCRA section 3004(n) reflects

a congressional intend that the EPA regulate air emissions only from

permitted and interim-status TSDF and not from 90-day tanks and

containers. These tanks and containers are physically identical (i.e.,

the same types of tanks and containers are used by generators to

accumulate and by TSDF owners and operators to store and treat waste).

There is no environmental basis for not considering them subject to the

section 3004(n) mandate. Such units are, in fact, storing or treating

hazardous waste and are subject to numerous standards promulgated under

the authority of both RCRA sections 3002 and 3004. The exemption of 90-

day tanks and containers from the permitting requirements of RCRA

subtitle C is regulatory, not statutory; there is no directive in the

RCRA legislation that precludes the EPA from imposing any or all of the

TSDF requirements on them. The use of the term ``facility'' in RCRA

section 3004(n) can certainly be read to encompass 90-day tanks and

containers, given the EPA's flexibility to construe that term (see

United Technologies v. EPA, 821 F.2d at 814 (D.C. Cir. 1988) and the

fact that 90-day tanks and containers are already subject to the

substantive standards for tanks and containers and pose precisely the

same potential environmental risks as other tanks and containers

holding hazardous waste. In addition, the EPA sees to reason that

Congress intended 90-day tanks and containers to be subject to air

emission controls at a different time than other tanks and containers

(which would be the case if the 90-day units are not regulated pursuant

to a HSWA provision).

Therefore, it is proper for the EPA to use its authority under RCRA

section 3004(n) to amend 40 CFR 262.34(a) by adding air emission

control requirements to the conditions required for a 90-day tank or

container to be exempted from the RCRA permitting requirements. For

these reasons, the EPA rejects the commenters' arguments that the

Agency is not authorized or failed to cite authority to use this

rulemaking to amend the exemption requirements for 90-day tanks and

containers. In addition, the EPA rejects the argument that the

exemption requirements are under the EPA's pre-HSWA authority and,

therefore, are not applicable in authorized States until the individual

States are authorized to implement the rule (See 51 FR 25464, July 14,

1986, where the EPA indicated that the modifications to 40 CFR 262.34,

to reflect amended tank standards, were HSWA rules).

As a variation of the argument that 90-day tanks and containers

should not be regulated, one commenter asserts that RCRA section

3004(n) reflects a congressional intent that the EPA regulate air

emissions only from permitted and interim-status TSDF and not from 90-

day tanks and containers. The commenter apparently argues that the

explicit inclusion of such authority under RCRA section 3004(n) and not

under RCRA section 3002 implies a congressional finding that waste

accumulation does not significantly contribute to air pollution. The

EPA finds no indication, in the legislative history of RCRA, or

elsewhere, that Congress ever made such a finding, and the EPA's

conclusion, as discussed later in this section, is that on-site

accumulation of hazardous waste in 90-day units is a significant source

of organic air emissions. Again, the EPA finds no indication that

Congress intended to preclude the EPA from regulating air emissions

from nonpermitted hazardous waste storage and treatment under RCRA

section 3004(n).

In addition to RCRA section 3004(n), the EPA has authority under

RCRA section 3002 to amend 40 FR 262.34(a). One commenter states that,

although RCRA section 3002(a)(3) authorizes the EPA to require the use

of appropriate containers, RCRA section 3002 provides no authority to

regulate air emissions. The EPA disagrees with this statement. The RCRA

section 3002(a)(3) authority, as well as the general authority under

RCRA section 3002 to promulgate such rules regulating generators ``as

may be necessary to protect human health and the environment,'' is

broad enough to encompass the regulation of air emissions from units

storing or treating hazardous waste at generator facilities.

Finally, the EPA cited both RCRA sections 3002 and 3004 as the

statutory authority for the proposed rule. Therefore, this rulemaking

is in full conformance with section 553(b)(2) of the Administrative

Procedures Act.

The EPA also rejects the argument that the application of air

emission controls to 90-day tanks and containers impermissibly

interferes with manufacturing processes. The EPA concluded in 1980, as

cited above, that the appropriate balance between protection of the

environment and noninterference with manufacturing processes was

achieved by requiring 90-day tanks and containers to comply with

certain technical requirements as a condition of being exempt from the

requirement to have a RCRA permit. The EPA estimates that nationwide

baseline organic emissions from 90-day tanks and containers are

approximately 76,000 Mg/yr. Given the significant organic emissions

from 90-day tanks and containers, the same rationale has led the EPA to

require that these units comply with the appropriate air emission

control requirements of the subparts AA, BB, and CC standards to

maintain an exemption from RCRA permitting. In contrast, the EPA

decided not to extend under this rulemaking the requirements of these

air standards to containers used for satellite accumulation because of

the widespread use of these containers by manufacturing process

operators to collect small quantities of hazardous waste as generated,

and the integrated use of these containers with the manufacturing

operations (discussed further in section 7.2 of the BID for today's

rule). The EPA believes that this regulatory framework maintains the

appropriate balance between environmental protection and

noninterference with manufacturing processes.

E. Implementation of RCRA Air Standards

Comment: A total of 24 commenters addressed the EPA's proposed

action of modifying the ``permit-as-a-shield'' practice to require that

owners and operators of TSDF that have been issued final permits prior

to the effective date of this rulemaking comply with the air standards

under 40 CFR 265 subparts AA, BB, and CC until the facility's permit is

reviewed or reissued by the EPA. Four of the commenters support the

EPA's proposed modification. The other 20 commenters oppose the

proposed modification and maintain that ``permit-as-a-shield'' practice

should remain unchanged because any action by the EPA to remove this

practice:

(1) Is without the legal authority and that to do so would be

contrary to congressional intent;

(2) Violates the due process rights of permittees, which are

normally protected through the permit process;

(3) Negates the purpose and importance of the RCRA permit because

the ``permit-as-a-shield'' practice serves to unify all the regulatory

requirements in the permit for a TSDF;

(4) Is contrary to previously stated policy whereby the EPA binds

itself to the principle of using ``permit-as-a-shield'' (45 FR 33290,

May 19, 1980); and

(5) Is disruptive to TSDF owner and operator planning, burdensome

to comply with, and has an adverse effect on the availability and cost

of control equipment.

Response: The practice known as ``permit-as-a-shield'' is derived

from an exercise of the EPA's regulatory authority and was first

codified in the 1980 implementing regulations of the RCRA permit

program (45 FR 33290, May 19, 1980). It is not a provision of RCRA and

is therefore no part of the statutory mandate by Congress to manage the

Nation's hazardous wastes. Shell Oil v. EPA, 950 F.2d at 741, 762 (D.C.

Cir. 1991). Because it is a regulatory and not a statutory provision,

the EPA can modify the ``permit-as-a-shield'' practice in any situation

where the Agency determines that the practice does not serve the EPA's

mandate to protect human health and the environment. For the final

subpart CC standards, the EPA estimates that baseline nationwide excess

cancer incidence resulting from exposure to TSDF organic emissions is

48 cases per year. In addition, total nationwide organic emissions from

TSDF are estimated to be approximately 1 million Mg/yr and, thus,

contribute significantly to the formation of atmospheric ozone. These

health and environmental impacts are very high relative to the impacts

of emissions from other sources regulated under RCRA and the CAA.

Accordingly, the EPA has determined that the health and environmental

impacts resulting from organic air emissions from TSDF are of a

magnitude to warrant narrowly rescinding the ``permit-as-a-shield''

practice for this limited case.

The ``permit-as-a-shield'' practice is not a consequence of

Constitutional or statutory obligations of the EPA to any individual

and its removal does not violate any substantive or procedural due

process rights of individuals. The ``permit-as-a-shield'' practice was

established by regulations promulgated by the EPA and therefore can be

modified when the EPA determines it is necessary to do so for the

protection of human health and the environment. Numerous government

regulations have a direct effect on regulated entities, and the EPA's

``permit-as-a-shield'' practice does not vest the regulated community

with a right to a variance from all new RCRA regulations. Furthermore,

the proposal put the public on notice that the EPA was planning to

modify the ``permit-as-a-shield'' practice in this rule, and the public

has therefore had an opportunity for meaningful comment on the issue.

The EPA continues to believe that the permit process and

requirements are fundamental components of the RCRA program and that,

by and large, compliance with the permits should constitute compliance

with the RCRA program. For the other rulemakings for which the EPA

rescinded the ``permit-as-a-shield'' practice, the EPA determined that

the risk to human health and the environment was too high to allow the

practice to continue (for remaining permit periods), and required that

all TSDF comply with the new requirements regardless of their permit

status. The EPA has determined that allowing owners and operators of

permitted TSDF to be shielded from compliance with the regulatory

requirements of subparts AA, BB, and CC standards will allow

excessively high risks. Today's action by the EPA does not negate the

value of the RCRA permit program or the ``permit-as-a-shield''

practice. Instead, the EPA is making a distinction between a provision

that is sufficiently protective in most cases and one that, under

specific situations, is not sufficiently protective.

The EPA disagrees with the commenters' claims that the permit

modification process can adequately accommodate the timely

implementation of the subpart CC standards. For the EPA to apply the

subpart CC standards into permits by way of modifications would require

a significant and unreasonable resource commitment. Furthermore, the

fact that existing permits can be modified to incorporate new

regulatory requirements [per 40 CFR 270.41(a)(3), which implements RCRA

section 3005(c)(3)] shows that ``permit-as-a-shield'' is hardly an

inviolate principle. The ruelmaking simply accomplishes nationally what

a modification would accomplish individually. Accordingly, the EPA

developed the subpart AA, BB, and CC standards to be ``self-

implementing'' so that State and Regional permit writers will not be

required to reopen and rewrite permits to incorporate the provisions.

Permitted facilities will be able to comply directly with the

regulatory standards in the same way that interim-status facilities

must comply. Modifying ``permit-as-a shield'' for these rules

eliminates any confusion or ambiguity as to which TSDF is subject to

the requirements.

As noted by the commenters, the EPA stated a policy for ``permit-

as-a-shield'' in the so-called consolidated permit regulations issued

in 1980 (45 FR 33290). However, this does not mean that the policy for

``permit-as-a-shield'' can never be amended. The EPA has never agreed

to ``bind'' itself to any particular policy or provision. Instead, the

EPA may adhere to a general practice or policy with the understanding

that, if the circumstances warrant and the EPA provides a rational

explanation, it can modify or rescind a particular provision. It should

be noted, for example, that Congress has since amended RCRA to require

that air emissions from TSDF be controlled, and in the same amendments

provide that the EPA may reopen permits to add conditions reflecting

new control practices and to redress potential risks posed by the

facility (RCRA section 3005(c)(3) and S. Rep. No. 284, 98th Cong. 1st

Sess. at 31). Here, the EPA is determining that there are excessively

high risks from these facilities, and therefore that these more

protective provisions should become effective immediately.

It should also be noted that the EPA does not intend to rescind

``permit-as-a-shield'' on a regular or frequent basis for other

rulemakings. As stated earlier, the EPA generally does view ``permit-

as-a-shield'' as a beneficial and legitimate part of the RCRA program

and that, in most cases, it will apply.

The EPA believes that the commenters claiming that removing

``permit-as-a-shield'' will be disruptive to TSDF implementation

planning are greatly overstating the adverse or disruptive effects that

an accelerated implementation will have on TSDF owner and operator

planning and operations because the control technologies for the

different kinds of management units are varied and widely available.

The EPA specifically considered the costs and economic impacts of the

various control options in the regulatory impact analysis for the

proposed rule (RCRA docket entry number F-91-CESP-S00494). Based on

this analysis, the EPA found that the costs of installing and operating

air emission control equipment required by the control options are

projected to be less than 1 percent of the total cost of hazardous

waste management at TSDF. Any air emission control equipment supply

availability constraints resulting from these rules should be short

term, if at all. Furthermore, TSDF owners and operators required to

install air emission control equipment to comply with the subpart CC

standards are allowed up to an additional 30 months after the rule's

effective date to complete the equipment design and installation if

they can document that the air emission controls cannot be installed

and operating by the effective date, for reasons such as the

unavailability of control equipment.

Also, the EPA expects that many TSDF owners and operators will

choose to treat their hazardous waste earlier in the management

sequence that they now do to reduce the organic content of the waste in

accordance with one of the treatment requirements allowed for in the

final subpart CC standards, and thus avoid the cost of installing and

operating the control equipment on the downstream tanks, surface

impoundments, and containers. The EPA also encourages the use of

pollution prevention techniques as a means of reducing the quantity of

waste generated, the organic concentration of the waste, or the

toxicity of constituents in the waste.

F. Waste Stabilization in Tanks

Just prior to the long-scheduled and publicly-known promulgation

date, representatives from the hazardous waste treatment industry

notified the EPA of their opinion that the draft requirements for waste

stabilization operations performed in tanks are economically and

technically infeasible. These draft requirements are included in a May

19, 1994 interim review draft of the final rule, made publicly

available in June 1994. (See RCRA docket entry number F-94-CESP-

S00509.) Moreover, the industry indicated that volatilization of

organic constituents during stabilization operations are negligible. No

data were submitted to the EPA in support of these assertions. Industry

representatives nevertheless feel strongly that for the majority of

waste streams treated by stabilization, the organic constituents in the

waste are not volatilized during the stabilization process.

Additionally, they allege that for these same stabilization operations:

(1) It is technically infeasible to comply with the air emission

control requirements for tanks in the subpart CC standards; and

(2) It is not feasible to treat organic waste prior to

stabilization such that the volatile organic concentration of the waste

entering the stabilization process would be below 100 ppmw, and the

downstream units managing the waste (including the stabilization tanks)

would thereby be exempt from subpart CC tank control requirements. (See

RCRA docket number F-94-CESF-FFFFF.)

These statements contradict the conclusions drawn by the EPA based

on site visits to observe hazardous waste stabilization processes, and

experiments and studies conducted by the EPA to characterize waste

stabilization processes and estimate associated organic emissions. The

most recent EPA studies were mentioned in the Notice of Data

Availability (see 57 FR 43171, September 18, 1992) and were made

available for public review and comment in the docket for this

rulemaking (see RCRA docket number F-92-CESA-FFFFF). No comments were

received concerning the validity of these stabilization study

conclusions.

At the same time, however, and despite the inappropriate timing of

industry's comments on this issue (compounded by the industry's failure

to comment on the information presented by the Notice of Data

Availability), the EPA has determined that it may be worthwhile to

review pertinent data for current waste stabilization activities at

hazardous waste TSDF. Industry has pledged to provide detailed data

from an emissions test conducted to measure organic emissions from a

full-scale stabilization operation treating hazardous waste streams.

The test will be conducted using the EPA approved sampling and

analytical methods, and the volatile organic concentration of the waste

streams will be measured using Method 25D, with gas chromatography and

with mass spectrometry (see RCRA docket number F-94-CESF-FFFFF). The

EPA will accept until September 6, 1995 all pertinent information and

comments on the following limited issues: (1) Volatilization of

organics during waste stabilization activities, (2) feasibility of

treating organic wastes to destroy or remove organics prior to

stabilization to immobilize toxic metals, and (3) alternative organic

emission controls applicable to stabilization tanks. Persons interested

in submitting comments or data pertaining to these issues should notify

the EPA of their intent by contacting Ms. Michele Aston at the address

listed in the FOR FURTHER INFORMATION CONTACT section at the beginning

of this preamble. Written information and comments regarding the above

issues should be mailed to the RCRA Docket Office (5305), U.S.

Environmental Protection Agency, room 2616, 401 M Street SW.,

Washington, DC 20460. Please send an original and two copies of all

information, and refer to RCRA docket number F-94-CESA-FFFFF.

The EPA will assess all submitted information, and will make a

rapid determination whether to amend the requirements under the subpart

CC standards being promulgated today for tanks in which waste

stabilization operations are performed. The EPA emphasizes that the

current record does not support any amendment to these standards.

However, if the EPA were to amend the requirements for stabilization

tanks, the amendment could include any of the provisions described

below, a modification of today's promulgated requirements, or possibly

other options.

The EPA may choose to amend the final subpart CC tank standards

such that stabilization tanks could comply with alternative air

emission controls to those included in today's promulgation. The EPA

will determine the appropriateness of such an amendment based on the

evaluation of:

(1) Information that is submitted relating to industry's comments

that it is not feasible to comply with the technical requirements of

today's final rule or to pretreat waste prior to stabilization;

(2) Information related to alternative emission controls that could

be applied to stabilization tanks for effective organic emission

reduction;

(3) Data related to the specific characteristics of hazardous waste

that is stabilized at TSDF;

(4) Detailed information regarding the stabilization processes

performed in TSDF tanks; and

(5) Other related information.

For a given stabilization tank to qualify for certain compliance

options, the EPA could require the facility owner or operator to

demonstrate (through specified testing, monitoring, sampling, or other

means) that organic constituents are not volatilized during the

hazardous waste stabilization operations performed in that tank. A

similar requirement for biological treatment performed in tanks and

surface impoundments is included in the final subpart CC standards (for

example see 40 CFR 264.1085(a)(2)) as well as other air standards

developed by the EPA under the Clean Air Act (e.g., the Hazardous

Organic NESHAP (59 FR 19402, April 22, 1994) and the proposed Off-Site

Waste and Recovery Operations NESHAP (59 FR 51919, October 13, 1994)).

For biological treatment processes, which are generally acknowledged by

the EPA as appropriate treatment for organic constituents in waste with

respect to controlling organic emissions, the EPA considers such a

demonstration to be a reasonable requirement for certain compliance

options. Therefore, the EPA also could consider it reasonable to

require that stabilization operations, which the EPA does not consider

appropriate treatment for organic constituents in waste with respect to

controlling organic emissions, perform at least an equivalent

demonstration for certain compliance options. If the EPA were to amend

today's promulgated subpart CC tank standards to include such a

demonstration, the required procedure could include any of the

following, or possibly other procedures: whole waste analyses, full-

scale analyses, specified emissions monitoring, material balance

calculations, temperature monitoring, and water content information.

In light of this supplemental comment opportunity, the EPA

considers it appropriate to extend the effective date of the final

rules for tanks that could be affected if the EPA chooses to modify the

standards. Therefore, a separate compliance schedule is applicable to

tanks in which waste stabilization activities are performed as of

December 6, 1994. It is important to note that all applicable

requirements with respect to other units at a facility subject to the

subpart CC standards will be effective June 5, 1995. For these

stabilization tanks, the effective date of the final rules will be

December 6, 1995. As of the extended effective date for stabilization

tanks, each TSDF owner or operator and each hazardous waste generator

subject to the final rules must either install and operate the

specified air emission control requirements on all affected tanks used

for stabilization, or begin performing the specified waste

determinations and recordkeeping to indicate that a stabilization tank

is exempted from these requirements. Under circumstances where required

air emission control equipment cannot be operational by December 6,

1995, an implementation schedule for installation of the required air

emission controls must be developed and placed in the facility

operating records no later than December 6, 1995. In such cases, the

facility must have all air emission controls required by the final

rules in operation no later than June 8, 1998.

VII. Requirements of Final Rule

A. TSDF Tank, Surface Impoundment, and Container Requirements

Today's action by the EPA promulgates air emission standards for

TSDF tanks, surface impoundments, and containers as a new subpart CC in

both 40 CFR parts 264 and 265. Subpart CC under 40 CFR part 265

establishes standards for owners and operators of interim-status TSDF.

As discussed in section VIII.A of this preamble, owners and operators

of permitted TSDF that have been issued final permits prior to June 5,

1995, are required to comply with subpart CC under 40 CFR part 265

until the facility's permit is reviewed or reissued by the EPA.

The air emission control requirements of the final subpart CC

standards in 40 CFR part 264 and 40 CFR part 265 are identical with the

exception of the reporting requirements. There are no reporting

requirements in subpart CC under 40 CFR part 265.

1. Applicability

a. General applicability. In general, the subpart CC standards

apply to RCRA-permitted tanks, surface impoundments, and containers

subject to 40 CFR part 264, subparts J, K, or I, respectively, as well

as to interim-status TSDF tanks, surface impoundments, and containers

subject to 40 CFR part 265, subparts J, K, or I, respectively. However,

certain specific types of TSDF tanks, surface impoundments, and

containers are not subject to the subpart CC standards under

applicability provisions in other RCRA regulations as well as

provisions included specifically in the subpart CC standards.

The subpart CC standards do not apply to those TSDF tanks, surface

impoundments, or containers excluded from regulation under 40 CFR

264.1. For example, TSDF owners and operators are not required to

obtain a RCRA permit for tanks or tank systems that manage hazardous

wastewaters or wastewater treatment sludges and are subject to

regulation under either section 402 or 307(b) of the Clean Water Act

[refer to 40 CFR 264.1(g)(6) and 40 CFR 265.1(c)(10)]. Because these

tanks are exempted from RCRA permitting requirements, they are not

subject to the requirements of 40 CFR parts 264 and 265. Thus, the

subpart CC standards do not apply to a TSDF tank that is considered to

be a part of a ``wastewater treatment unit'' as defined in 40 CFR

260.10. Similarly, the subpart CC standards do not apply to TSDF tanks,

surface impoundments, or containers when these units are used for

emergency or spill management activities in accordance with 40 CFR

264.1(g)(8)(i) or 40 CFR 265.1(c)(11)(i).

b. Exemptions. The subpart CC standards are only applicable to

containers with a design capacity greater than or equal to 0.1 m\3\

(approximately 26 gallons). This means that any container that has a

design capacity less than 0.1 m\3\ is not subject to the subpart CC

standards regardless of the volatile organic concentration of the

hazardous waste placed in the container.

The subpart CC standards apply only to TSDF tanks, surface

impoundments, and containers in which an owner or operator places

hazardous waste on or after June 5, 1995. With respect to surface

impoundments, the EPA has already explained that RCRA regulations do

not apply to impoundments at which there is no active management of

hazardous waste after the rule's effective date (see 55 FR 39410,

September 27, 1990). This would include impoundments that cease

operation before the rule's effective date, and impoundments that

convert to non-hazardous waste impoundments before the effective date.

This latter class of impoundments includes those impoundments that

contain hazardous wastes deposited before the rule's effective date for

which the impoundment is the final disposal site for hazardous waste

already in the unit (i.e., the impoundment is a disposal unit) and

hazardous wastes are not actively managed in the impoundment. Id. The

principle in today's rule is consistent with this existing

interpretation.

The rationale for not applying the subpart CC standards to tanks

and containers that do not receive hazardous waste after the effective

date is somewhat different. Under the subpart CC standards, the need to

apply air emission controls to a particular tank or container is

determined by the organic content of the hazardous waste at a point

prior to being placed in the tank or container (this is discussed in

the following section under ``General Standards''). In many situations

where existing tanks and containers at a TSDF already hold hazardous

waste but no longer receive new wastes, a TSDF owner or operator will

be unable to perform a waste determination as specified in the rule

because waste samples cannot be collected at the required locations and

the owner or operator has insufficient knowledge about the waste.

Furthermore, even if a waste determination can be performed for these

tanks or containers but the units presently are uncovered or have other

openings, most if not all of the volatile organics in the waste have

most likely already been emitted to the atmosphere. Thus, the EPA

decided that air emission control requirements should only apply to

those tanks and containers in which hazardous waste is placed on or

after the effective date of the rule.

The EPA decided not to apply the subpart CC standards to a tank

once an owner or operator stops adding hazardous waste to the unit and

begins closure pursuant to an approved closure plan because in many

cases, use of the required air emission controls would hinder or

prevent closure activities from being performed.

c. Remediation wastes. The EPA has further decided to temporarily

defer application of the subpart CC standards to tanks, containers, and

surface impoundments which are being used on-site to treat or store

hazardous wastes containing organics generated from remedial activities

required under RCRA corrective action or CERCLA response authorities,

or similar State remediation authorities, provided that the wastes are

managed in units that do not also manage other hazardous wastes. This

deferral applies only to on-site management of such wastes. For

remediation waste transported off-site, the point of waste origination

will be the point at which the wastes are physically moved outside the

facility boundary (or for CERCLA response actions, outside the site

boundary).

As the D.C. Circuit recently explained, a temporary deferral such

as today's is permissible if the Agency legitimately needs further time

to ascertain the best means of integrating concurrent statutory and

regulatory schemes to avoid potential interference with the objectives

of both schemes, and where Congress has not expressly forbidden a

temporary deferral. Edison Electric Inst. v. EPA, 2 F. 3d 438, 451-53

(D.C. Cir. 1993). See also RCRA section 1006, requiring the EPA to

integrate all provisions of RCRA for purposes of administration and

enforcement, and to avoid duplication to the maximum extent practicable

in doing so.

This situation is presented here. Control of air emissions from

units at remediation sites implicates the overlapping and potentially

competing concerns of RCRA section 3004(n) and the complex statutory

provisions under RCRA, CERCLA, and State laws relating to remediation.

The EPA's primary goal in this rulemaking has been to develop air

emission standards for tanks, containers, and surface impoundments

holding as-generated hazardous wastes containing organics. At proposal,

the EPA thus did not fully consider the issue of whether different

standards should appropriately apply to wastes that are generated and

managed as the result of remedial activities, or how the proposed rule

for air emissions could best be integrated with the remediation

authorities of RCRA and other Federal or State laws. 56 FR at 33497-98

(July 22, 1991).

Commenters on the proposed subpart CC regulations pointed out that

these were important issues deserving careful attention. The EPA

agrees. It is possible that certain provisions of the air emission

requirements promulgated today may be inappropriate or unnecessarily

restrictive if applied to remediation activities (see 58 FR 8660,

February 16, 1993).

The EPA notes that some measure of control of air emissions from

remediation tanks, containers, and impoundments will be assured during

the deferral period. Remediation authorities of RCRA and CERCLA and

similar State authorities allow overseeing officials to impose, on a

site-specific basis, appropriate air emission controls on these types

of units, as well as on other waste management units and handling

operations. In addition, hazardous wastes containing organics that are

managed off-site (i.e., outside a RCRA facility's boundary, or outside

a CERCLA site) would be subject to the subpart CC management standards.

Finally, the EPA emphasizes that the deferral is indeed temporary.

The issue of appropriate air emission controls for remediation units is

likely to be addressed in the context of the Hazardous Waste

Identification Rules which are currently being developed by the EPA.

The issue is also potentially part of the third phase of the RCRA

section 3004(n) implementation. In addition, waste remediation sites

are on the initial list of source categories under CAA section 112, and

the EPA currently is scheduled to issue technology-based standards to

control emissions of hazardous air pollutants from this source (see 57

FR 31576, July 16, 1992). Consequently, the EPA will be addressing this

issue in the reasonably near future.

d. Radioactive mixed wastes. As explained in section IV.F of this

preamble, the management of radioactive mixed waste at TSDF is subject

to regulation under subtitle C of RCRA. The EPA reviewed the special

nature of radioactive mixed wastes with respect to the air emission

control requirements under the final subpart CC standards. In certain

cases, the air emission controls used as the basis for the subpart CC

standards are not compatible with the NRC requirements for safe

handling of radioactive mixed wastes. For example, drums used to store

radioactive mixed waste cannot be sealed with vapor leak-tight covers

because of unacceptable pressure buildup of hydrogen gas to levels that

can potentially cause rupture of the drum or create a potentially

serious explosion hazard. This generation of hydrogen gas results from

the radiolytic decomposition of organic materials (e.g., plastics) or

aqueous solutions stored in the drums. Consequently, a drum used for

storage of radioactive mixed wastes must be continuously vented through

special filters in accordance with technical guidance issued by the NRC

to prevent the hydrogen concentration in the drum from reaching

dangerous levels. The EPA is planning to further investigate methods

for effective control of organic emissions from waste management units

handling radioactive mixed waste that are consistent with the NRC waste

management practices.

2. General Standards

The final subpart CC standards require that TSDF owners and

operators install and operate air emission controls on each tank,

surface impoundment, and container subject to the rules except when all

of the hazardous waste placed in the unit is determined to meet certain

conditions. These conditions are based on properties of the hazardous

waste determined at either one of two locations:

(1) The point where a hazardous waste is generated or the point

where the waste is received by an off-site facility; or

(2) The point following treatment of a hazardous waste to remove or

destroy the organics in the waste.

a. Point of waste origination. Under the final subpart CC

standards, a TSDF owner or operator is exempted from managing a

hazardous waste in a tank, surface impoundment, or container in

accordance with the air emission control requirements of the rule when

the owner or operator determines that all hazardous waste placed in the

unit has an average volatile organic concentration at the point of

waste origination less than 100 ppmw. The point of waste origination is

defined in the rule with respect to the point where the TSDF owner or

operator first has possession of a hazardous waste. When the TSDF owner

or operator is the generator of the hazardous waste, the point of waste

origination means the point where a solid waste produced by a system,

process, or waste management unit is determined to be a hazardous waste

as defined in 40 CFR part 261. As previously stated, the term ``point

of waste origination'' applied to this situation is being used in a

similar manner to the use of the term ``point of generation'' in waste

operations air standards established under authority of the Clean Air

Act in 40 CFR parts 60, 61, and 63 of this chapter. When neither the

TSDF owner nor operator is the generator of the hazardous waste, point

of waste origination means the point where the owner or operator

accepts delivery or takes possession of the hazardous waste.

b. Treated Hazardous Waste. If a hazardous waste has an average

volatile organic concentration equal to or greater than 100 ppmw based

on the hazardous waste composition at the point of waste origination,

then this waste is required under the subpart CC standards to be

managed in accordance with the air emission control requirements of the

rule. Under these requirements, specific air emission controls must be

installed and operated on every tank, surface impoundment, and

container subject to the rule used in the waste management sequence

from the point of waste origination through the point where the

organics in the waste are removed or destroyed by a process that meets

or exceeds a minimum level of performance specified in the rule. In

other words, once a hazardous waste is treated to remove or destroy the

organics in the waste in accordance with the rule requirements, the

subsequent downstream tanks, surface impoundments, and containers used

to manage this particular hazardous waste are not required to meet the

air emission control requirements of the subpart CC standards.

The final subpart CC standards provide TSDF owners and operators

with several alternative provisions for determining when a treated

hazardous waste is no longer required to be managed in tanks, surface

impoundments, and containers meeting the air emission control

requirements of the rule. Treated hazardous waste provisions are

specified in the subpart CC standards for the following processes:

(1) An organic destruction, biological degradation, or organic

removal process that reduces the organic content of the hazardous waste

and is designed and operated in accordance with certain conditions

specified in the rule;

(2) A hazardous waste incinerator that is designed and operated in

accordance with the requirements of 40 CFR 264 subpart O or 40 CFR 265

subpart O; or

(3) A boiler or industrial furnace that is subject to the

requirements of 40 CFR part 266 subpart H.

A process that simply mixes, blends, combines, or aggregates a

hazardous waste stream with other materials does not destroy the

organics in the waste stream or remove the organics from the waste

stream. While diluting a hazardous waste stream having a volatile

organic concentration greater than 100 ppmw with sufficient quantities

of other hazardous waste streams having a volatile organic

concentration less than 100 ppmw (or water or other low organic content

materials) would reduce the volatile organic concentration of the

resulting hazardous waste mixture to a level below 100 ppmw, the total

mass quantity of organics in the waste does not change since no

organics were removed or destroyed from the waste. The potential for

organic emissions from handling the waste mixture is essentially the

same as for the individual hazardous waste streams prior to being

mixed. Therefore, the EPA does not allow dilution of a hazardous waste

as a means for complying with the requirements specified in the subpart

CC standards for placing treated hazardous waste in affected tanks,

surface impoundments, or containers not using the required air emission

controls. Consequently, when a hazardous waste is treated by an organic

destruction or removal process and the hazardous waste has been mixed

or aggregated together with other hazardous wastes or materials with a

volatile organic concentration less than 100 ppmw prior to the point of

waste treatment, the subpart CC standards require that TSDF owners and

operators meet special requirements to ensure that organics in the

hazardous waste have actually been removed or destroyed. An owner or

operator can choose from several alternative provisions to comply with

these requirements.

One provision requires that mixed hazardous wastes be treated by an

organic destruction or removal process that reduces the volatile

organic concentration of the hazardous waste to meet a site-specific

treatment process exit concentration limit. This limit is determined by

the TSDF owner or operator on a case-by-case basis using an equation

specified in the rule that accounts for the portion of the reduction in

the volatile organic concentration in the resulting treated hazardous

waste stream due to dilution. To use this equation, the owner or

operator must first determine the volatile organic concentration at the

point of waste origination for each individual hazardous waste stream

that is mixed together prior to entering the treatment process. As an

alternative to calculating the exit concentration limit for a treatment

process, the subpart CC standards allow the owner or operator to treat

the mixed hazardous wastes to a volatile organic concentration level

that is less than or equal to the lowest waste volatile organic

concentration at the point of waste origination for all of the

individual hazardous waste streams mixed together prior to entering the

treatment process.

Another alternative in the subpart CC standards available to owners

and operators allows mixed hazardous wastes to be treated using a

single process that achieves an organic reduction efficiency of 95

percent or greater on a mass basis, and reduces the average volatile

organic concentration of the resulting hazardous waste stream exiting

the process to a level less than 50 ppmw. This alternative does not

require the owner or operator to perform any volatile organic

concentration waste determinations for the hazardous wastes prior to

mixing, yet still accommodates the mixing of wastes that have different

volatile organic concentrations. For a waste stream having a volatile

organic concentration greater than 2,000 ppmw, requiring only a minimum

95 percent reduction of the organic content in the waste stream would

not lower the volatile organic concentration of the treated waste

stream to the 100 ppmw level of the rule. However, if such a waste

stream had been mixed together prior to treatment with other waste

streams having lower volatile organic concentrations, then the volatile

organic concentration of the treated waste exiting the process could be

less than 100 ppmw. The EPA does not consider such situations to be

unlikely, and has therefore chosen for this alternative to require an

exit concentration for the treated waste lower than 100 ppmw. The EPA

considers an exit concentration of 50 ppmw, combined with a 95 percent

treatment efficiency, to be an appropriate demonstration that the

reduction in volatile organic concentration for a mixture of hazardous

waste streams has been achieved through destruction or removal of

organic constituents in the waste, rather than by dilution.

The final subpart CC standards also provide another alternative

that does not require the owner or operator to perform any volatile

organic concentration waste determinations for the hazardous wastes

prior to mixing when the waste is treated by a biological process that

destroys or degrades the organics contained in the hazardous waste to

meet certain performance requirements specified in the rule. These

conditions are either of the following:

(1) Achieve an organic reduction efficiency for the biological

treatment process equal to or greater than 95 percent, and achieve an

organic biodegradation efficiency for the process equal to or greater

than 95 percent; or

(2) Achieve a total actual organic mass biodegradation rate for all

hazardous waste treated by the process equal to or greater than the

required organic mass removal rate for the process.

Compliance with these parameters is determined using the procedures

specified in rule.

The EPA may at any time measure or request that the owner or

operator measure using Method 25D the volatile organic concentration of

a hazardous waste that is placed in a tank, surface impoundment, or

container not using air emission controls in accordance with the

requirements of the subpart CC standards. Measurement results showing

that the volatile organic concentration of the hazardous waste is equal

to or greater than 100 ppmw constitutes noncompliance with the subpart

CC standards. However, in a case where the owner or operator has used

an averaging period greater than 1 hour for determining the volatile

organic concentration of a hazardous waste, the Regional Administrator

may consider information that was used by the owner or operator to

determine the average volatile organic concentration of the hazardous

waste (e.g., test results, measurements, calculations, and other

documentation) together with the results of the waste determination in

determining whether the owner or operator is in compliance with the

subpart CC standards.

3. Waste Determination Procedures

A determination of the volatile organic concentration of a

hazardous waste is required by the subpart CC standards only when a

hazardous waste is to be placed in a tank, surface impoundment, or

container subject to the rule that does not use air emission controls

in accordance with the requirements of the rule. A TSDF owner or

operator is not required to determine the volatile organic

concentration of the waste if it is placed in a tank, surface

impoundment, or container using the required air emission controls.

When the hazardous waste is generated as part of a continuous

process, the owner or operator is required to perform an initial waste

determination of the average volatile organic concentration of the

waste stream before the first time any portion of the material in the

waste stream is placed in a waste management unit subject to the rule,

and thereafter update the information used for the waste determination

at least once every 12 months following the date of the initial waste

determination. When the hazardous waste is generated as part of a batch

process that is performed repeatedly but not necessarily continuously,

the owner or operator is required to perform an initial waste

determination of the average volatile organic concentration for one or

more representative waste batches generated by the process before the

first time any portion of the material in the these waste batches is

placed in a waste management unit subject to the rule, and thereafter

update the information used for the waste determination at least once

every 12 months following the date of the initial waste determination.

For either case, the owner or operator is required to perform a new

waste determination whenever changes to the process generating the

hazardous waste are reasonably likely to cause the average volatile

organic concentration to increase to a level at or above 100 ppmw. If

an average volatile organic concentration is used, an initial waste

determination must be performed for each averaging period.

Waste determinations should be performed for any waste that is

generated as a part of an unplanned event or is generated as a part of

an event that is not included in the normal operating conditions for

the source or process generating the hazardous waste. Examples of an

unplanned event include malfunctions that affect the operation of the

process or that alter the composition of the waste or product. Examples

of events that are not normal operating conditions include maintenance

activities and equipment cleaning. Normal operating conditions for the

source or process generating the waste include cyclic process

operations such as start-up and shutdown.

For processes that have variations in normal operating conditions

such that the waste volatile organic concentration may exceed 100 ppmw,

but for which the average waste volatile organic concentration for the

averaging period is below 100 ppmw, documentation must be retained in

the facility operating record that specifies the following information:

(1) The maximum and minimum waste volatile organic concentration values

that will occur for that averaging period; (2) the circumstances under

which a waste volatile organic concentration above 100 ppmw would

occur, and; (3) the calculations and waste determination procedures

used as the basis for the determination of the average volatile organic

concentration. For a given averaging period, if there are no deviations

from the operating circumstances or from the maximum or minimum waste

volatile organic concentrations specified in the operating plan, then

no additional waste determinations would be required after the initial

waste determination for that averaging period.

The subpart CC standards include provisions that allow a TSDF owner

or operator to use either direct measurement or knowledge of the waste

to determine the volatile organic concentration of a hazardous waste.

The following paragraphs describe these two options available to the

owner or operator for performing a waste determination.

a. Direct measurement. When the hazardous waste is generated on a

continuous basis, the averaging period to be used for determining the

volatile organic concentration on a mass-weighted average basis must be

designated and recorded. This averaging period can represent any time

interval that the hazardous waste flows until such time that a new

waste determination must be performed pursuant to the requirements of

the rule. However, this averaging period cannot exceed 1 year. A

sufficient number of samples, but no less than four, must be collected

to represent the complete range of organic compositions and organic

quantities that occur in the hazardous waste stream during the entire

averaging period due to normal variations in the operating conditions

for the source or process generating the hazardous waste.

When the hazardous waste is generated as part of a batch process

that is performed repeatedly but not necessarily continuously, samples

are collected from one or more representative waste batches generated

by the process. The volatile organic concentration for the waste is

calculated as a mass-weighted average based on the analysis results for

all of the waste samples collected for these waste batches. A

sufficient number of samples, but no less than four, must be collected

to represent the organic composition for each representative batch.

Each sample of the hazardous waste is to be collected in accordance

with the requirements specified in ``Test Methods for Evaluating Solid

Waste, Physical/Chemical Methods,'' EPA Publication No. SW-846, third

edition, November 1986, as amended by Update I, November 15, 1992.

Sufficient information must be recorded to document the waste quantity

and the operating conditions for the source, process, or waste

management unit generating the hazardous waste represented by each

sample collected.

Each of the collected waste samples is to be prepared and analyzed

in accordance with the requirements of Method 25D in 40 CFR part 60,

appendix A. The volatile organic concentration for a hazardous waste on

a mass-weighted average basis is then calculated by entering the

analysis results for all of the collected waste samples into an

equation specified in the rule.

b. Knowledge of the waste. The final subpart CC standards allow

TSDF owners or operators to use their knowledge of the waste for waste

determinations (see Hazardous Waste Treatment Council v. EPA, 886 F.2d

355, 370-71 (D.C. Cir. 1989) upholding the use of generator knowledge

to determine if treatment standards are met). Information may be used

that is prepared by either the facility owner or operator or by the

generator of the hazardous waste. Examples of information that could

constitute acceptable knowledge include:

(1) Organic material balances for the source, process, or waste

management unit generating the waste;

(2) Documentation that lists the raw materials or intermediate

products fed to a process showing that no organics are used in the

process generating the waste;

(3) Information that shows the waste is generated by a process that

is substantially similar to a process at the same or another facility

that generates a waste that has previously been determined by direct

measurement to have a volatile organic content less than the action

level;

(4) Test data that provide speciation analysis results for the

waste that are still applicable to the current waste management

practices and from which the total concentration of organics in the

waste can be computed; or

(5) Other knowledge based on manifests, shipping papers, or waste

certification notices.

When test data are used as the basis for knowledge of the waste,

the owner or operator must provide documentation describing the testing

protocol and the means by which sampling variability and analytical

variability are accounted for in the determination of the volatile

organic concentration of the hazardous waste. For example, an owner or

operator may use individual organic constituent concentration test data

that are validated in accordance with Method 301 in appendix A to 40

CFR part 63 as the basis for knowledge of the waste.

4. Tank Standards

The tank standards establish the requirements for tanks using air

emission controls to comply with the general standards of the rule. No

air emission controls are required under the subpart CC standards for a

tank in which all hazardous waste placed in the unit has been treated

to remove or destroy organics in accordance with the requirements

specified in the general standards.

Also, the tank standards do not apply to a tank in which biological

degradation of the organics in the hazardous waste treated in the unit

is demonstrated to achieve specific performance levels. Either of the

following sets of conditions must be demonstrated to qualify for this

exemption: (1) The organic reduction efficiency for the process is

equal to or greater than 95 percent, and the organic biodegradation

efficiency for the process is equal to or greater than 95 percent; or

(2) the total actual organic mass biodegradation rate for all hazardous

waste treated by the process is equal to or greater than the required

organic mass removal rate. The organic biodegradation efficiency or the

organic mass biodegradation rate for a biological treatment unit is

determined by procedures specified in the rule.

The tank standards specify that the owner or operator install and

operate on each affected tank one of the following air emission control

systems: (1) A cover that is connected through a closed-vent system to

a control device; (2) a fixed-roof type cover with an internal floating

roof that is designed and operated in accordance with the requirements

equivalent to the new source performance standard (NSPS) for volatile

organic liquid (VOL) storage; (3) an external floating roof that is

designed and operated in accordance with the requirements equivalent to

the VOL storage NSPS; or (4) a pressure tank that is designed to

operate as a closed system. Under the subpart CC standards, an owner or

operator is allowed to use a fixed-roof type cover (without any

additional controls) for affected tanks under certain conditions.

Four conditions must be met for a particular tank before use of a

fixed-roof type cover (without any additional controls) is allowed

under the subpart CC standards. First, the hazardous waste cannot be

mixed, stirred, agitated, or circulated within the tank by a process

that results in splashing, frothing, or visible turbulent flow on the

waste surface except during limited circumstances. Second, the

hazardous waste in the tank cannot be heated by the owner or operator

except when necessary to prevent the waste from freezing or to maintain

adequate waste flow conditions for continuous normal process

operations. Third, the hazardous waste cannot be treated using a waste

stabilization process or a process that produces an exothermic

reaction. Finally, the maximum organic vapor pressure of the hazardous

waste in the tank must be less than the limit established in the rule

by tank design capacity. For a tank having a design capacity equal to

or greater than 151 m\3\ (approximately 40,000 gallons), then the

maximum organic vapor pressure of the hazardous waste in the tank must

be less than 5.2 kPA. For a tank having a design capacity equal to or

greater than 75 m\3\ (approximately 20,000 gallons) but less than 151

m\3\, then the maximum organic vapor pressure of the waste in the tank

must be less than 27.6 kPa. For a smaller tank (design capacity less

than 75 m\3\), the maximum organic vapor pressure must be less than

76.6 kPa.

The subpart CC standards require each cover opening not vented to a

control device to be maintained in a closed, sealed position except at

those times when a specific opening must be used to add, remove,

inspect, or sample the waste in the tank or when it is necessary to use

the opening to inspect, maintain, or repair equipment located inside

the tank. Also, safety devices that vent directly to the atmosphere may

be used on the tank, cover, closed-vent system, or control device

provided that the safety device is not used for planned or routine

venting of organic vapors. These safety devices are to remain in a

closed position except when an unplanned event requires that the device

be open for the purpose of preventing physical damage or permanent

deformation of the tank, cover, closed-vent system, or control device

in accordance with good engineering and safety practices for handling

flammable, combustible, explosive, or other hazardous materials. An

example of an unplanned event is a sudden power outage.

5. Surface Impoundment Standards

The surface impoundment standards establish the requirements for

surface impoundments using air emission controls to comply with the

general standards of the rule. No air emission controls are required

under the subpart CC standards for a surface impoundment in which all

hazardous waste placed in the unit has been treated to remove or

destroy organics in accordance with the requirements specified in the

general standards. Also, air emission controls are not required for a

surface impoundment in which biological treatment of a hazardous waste

is performed under the same conditions specified in the rule for tanks.

The surface impoundment standards specify that the owner or

operator install and operate on each affected surface impoundment a

cover (e.g., air-supported structure) that is connected through a

closed-vent system to a control device. Under the subpart CC standards,

an owner or operator is allowed to use a floating membrane cover

(without any additional controls) for affected surface impoundments

under certain conditions specified in the rule.

The requirements under the subpart CC standards for surface

impoundment air emission control equipment are consistent with the

requirements for tanks.

6. Container Standards

The container standards establish the requirements for affected

containers (containers with a design capacity greater than or equal to

0.1 m\3\) using air emission controls to comply with the general

standards of the rule. No air emission controls are required by the

subpart CC standards for any container with a design capacity less than

0.1 m\3\ regardless of the volatile organic concentration of the

hazardous waste placed in the container.

For affected containers used for storage, treatment, or handling of

hazardous waste, the owner or operator is required to use either: (1) A

container that is equipped with a vapor leak-tight cover; (2) a

container having a design capacity less than or equal to 0.46 m\3\

(approximately 119 gallons) that is equipped with a cover and complies

with all applicable U.S. Department of Transportation (DOT) regulations

on packaging hazardous waste for transport under 49 CFR part 178; or

(3) a container that is attached to or forms a part of any truck,

trailer, or railcar and that has been demonstrated within the preceding

12 months to be organic vapor tight in accordance with the procedure

specified in Method 27. For a container in which treatment of hazardous

waste is perform

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