2/9/1

DIALOG(R)File 669:Federal Register

(c) 1997 Knight-Ridder Information. All rts. reserv.



00085936

 Corrective     Action   for  Solid   Waste   Management  Units (SWMUs) at

  Hazardous Waste Management Facilities

                       Vol. 55, No. 145

                            Part II

                          55 FR 30798

                    Friday, July 27, 1990



AGENCY: ENVIRONMENTAL PROTECTION AGENCY

DOC TYPE: Proposed Rules

CFR: 40 CFR Parts 264, 265, 270, and 271

NUMBER: FRL-3403-8; EPA/OSW-FR-90-012; RIN 2050-AB42

Written  comments  on  this  proposed rule should be submitted on or before

  September 25, 1990.



    Public hearings on this proposed rulemaking are scheduled as follows:



     October 9, 1990 in San Francisco, CA.



     October 12, 1990 in Washington, DC.

CONTACT:  



    Specific  questions  about  the  issues discussed in this proposed rule

  should  be  directed  to  David M. Fagan, Office of Solid Waste, OSW (renamed Office of Resource Conservation and Recovery, ORCR, on January 18, 2009) (OS-341),

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

  20460, (202) 382-4740.

The public hearings will be held at the following locations:



     October  9,  1990  at  the  Hyatt Regency San Francisco in Embarcadero

  Center,  5  Embarcadero  Center, San Francisco, CA 94111 (415-788- 1234);

  and



     October  12, 1990 at the Omni-Shoreham Hotel, 2500 Calvert Street NW.,

  Washington, DC 20008 (202-234-0700).



    Those  individuals  who wish to present oral testimony at either of the

  public hearings must request an opportunity to be heard. Requests must be

  made  in  writing  to  Thea  McManus,  Hearings  Clerk, Office of Program

  Management  (OS-305),  U.S. Environmental Protection Agency, 401 M Street

  SW.,  Washington,  DC  20460.  The  request  should  reference  the  RCRA

  Corrective  Action Proposed Rule, Regulatory Docket No. F- 90-CASP-FFFFF.

  Unless  otherwise  requested  in  writing,  individuals will be scheduled

  10-minute  time segments to present oral testimony. Time segments will be

  allotted  based  on the order in which the written requests are received.

  Written  requests  must  be  received  by  the end of the written comment

  period.



    Written  comments on today's proposal should be addressed to the docket

  clerk  at  the  following  address: U.S. Environmental Protection Agency,

  RCRA  Docket  (OS-305),  401  M  Street  SW.,  Washington,  DC 20460. One

  original  and  two  copies  should  be  sent and identified by regulatory

  docket  reference  number F-90-CASP-FFFFF. The docket is open from 9 a.m.

  to  4  p.m.,  Monday  through  Friday, excluding Federal holidays. Docket

  materials  may  be  reviewed  by  appointment  by calling (202) 475-9327.

  Copies  of docket materials may be made at no cost, with a maximum of 100

  pages  of  material from any one regulatory docket. Additional copies are

  $0.15 per page.

Proposed rule.

The  Environmental  Protection Agency is today proposing requirements under

  the  Resource  Conservation and Recovery Act (RCRA) for corrective action

  for  solid  waste management units (SWMUs) at facilities seeking a permit

  under  section  3005(c)  of RCRA. This proposal will establish procedures

  and  technical  requirements  for  implementing  corrective  action under

  section 3004(u) of RCRA.



    Today's  proposal  would  create  a  new subpart S in the RCRA part 264

  regulations    to    define    requirements   for   conducting   remedial

  investigations,   evaluating   potential   remedies,  and  selecting  and

  implementing  remedies  at RCRA facilities. It also proposes to amend the

  RCRA  part  270  permit requirements, make conforming changes to part 264

  and   265   facility  closure  information  requirements,  and  establish

  standards for States to become authorized to administer corrective action

  requirements.



WORD COUNT: 139,310

TEXT:

SUPPLEMENTARY INFORMATION:



Outline



I. Authority



II. Background

III. Purpose of Today's Rule



IV. EPA's Implementation of the Corrective Action Program to Date

A. Pre-HSWA RCRA Corrective Action

B. July 15, 1985, Codification Rule (50 FR 28702)

C. December 1, 1987, Codification Rule (52 FR 45788)

D. Proposed Rule, Financial Assurance for Corrective Action (51 FR 37854)

E.  National  RCRA  Corrective  Action  Strategy (51 FR 37608) and the RCRA

Corrective Action Outyear Strategy (Fall, 1989)

F. Implementation of the HSWA Corrective Action Program



V. Approach to Corrective Action in Today's Rule

A. Priorities and Management Philosophy for RCRA Corrective Action

B. Cleanup Goals for Corrective Action

C. Major Elements of Today's Proposal



VI. Section-by-Section Analysis

A. Purpose/Applicability (Sec. 264.500)

1.  Conforming Changes to Previous Codification of Sec. 3004(u) and General

Discussion

2. Exceptions to Applicability

a. Permits for Land Treatment Demonstrations

b. Emergency Permits

c. Permits-by-Rule for Ocean Disposal Barges or Vessels

d. Research, Development and Demonstration Permits

3. Voluntary Corrective Action

B. Definitions (Sec. 264.501)

1. Facility

2. Release

3. Solid Waste Management Unit (SWMU)

4. Hazardous Waste and Hazardous Constituents

5. Corrective Action Management Units

C. Remedial Investigations (Secs. 264.510-264.513)

1. General

2. Scope of Remedial Investigations (Sec. 264.511)

3. Plans for Remedial Investigations (Sec. 264.512)

4. Reports of Remedial Investigations (Sec. 264.513)

D. Determination of No Further Action (Sec. 264.514)

E. Corrective Measure Study (Secs. 264.520-264.524)

1. Purpose of Corrective Measure Study (Sec. 264.520)

2. Trigger for Corrective Measure Study (Sec. 264.521)

a. Use of Action Levels

b. Criteria for Determining Action Levels

c. Action Levels for Ground Water

d. Action Levels for Air

e. Action Levels for Surface Water

f. Action Levels for Soil

g.  Action  Levels  Where  Health-  and  Environmental-Based Levels Are Not

Available

h. Authority to Require a Corrective Measure Study Where Action Levels Have

Not Been Exceeded

3. Scope of Corrective Measure Study (Sec. 264.522)

4. Plans for Corrective Measure Study (Sec. 264.523)

5. Reports of Corrective Measure Study (Sec. 264.524)

F. Selection of Remedy (Sec. 264.525)

1. General (Sec. 264.525)

2. General Standards for Remedies (Sec. 264.525(a))

3. Remedy Selection Decision Factors (Sec. 264.525(b))

4. Schedule for Remedy (Sec. 264.525(c))

5. Media Cleanup Standards (Sec. 264.525(d))

a. General

b. Protectiveness

c. Cleanup Levels and Other Sources of Contamination

6. Determination that Remediation of Release to a Media Cleanup Standard is

Not Required {pg 30799}

a. Areas of Broad Contamination

b. Ground Water

c. Technical Impracticability

7.   Demonstration   of  Compliance  With  Media  Cleanup  Standards  (Sec.

264.525(e))

a. Points of Compliance

b. Methods

c. Timing of Demonstration of Compliance

8. Conditional Remedies (Sec. 264.525(f))

G. Permit Modification for Selection of Remedy (Sec. 264.526)

H. Implementation of Remedy (Secs. 264.527-264.531)

1. Remedy Design (Sec. 264.527)

2. Progress Reports (Sec. 264.528)

3. Review of Remedy Implementation (Sec. 264.529)

4. Completion of Remedies (Sec. 264.530)

5. Determination of Technical Impracticability (Sec. 264.531)

I. Interim Measures (Sec. 264.540)

J. Management of Wastes (Secs. 264.550-264.552)

1. Overview

2. General Performance Standard (Sec. 264.550)

3. Management of Hazardous Wastes (Sec. 264.551(a))

a. Temporary Units (Sec. 264.551(b))

b. Corrective Action Management Units (Sec. 264.551(c); Sec. 264.501)

4. Management of Non-Hazardous Solid Wastes (Sec. 264.552)

K. Required Notices (Sec. 264.560)

1. Notification of Ground-Water Contamination

2. Notification of Air Contamination

3. Notification of Residual Contamination

L. Permit Requirements (Secs. 270.1(c)-270.60(c)(3))

1. Requirement to Maintain a Permit (Sec. 270.1(c))

2. Schedules of Compliance for Corrective Action (Sec. 270.34)

3. Conditions Applicable to All Permits (Sec. 270.30(1)(12))

4. Information Repository (Sec. 270.36)

5. Major Permit Modifications (Sec. 270.41(a)(5)(ix))

6.   Conforming   Changes   to   Requirements   for  Permits-by-Rule  (Sec.

270.60(b)(3); Sec. 270.60(c)(3)(viii))

7. Alternative Dispute Resolution

M.  Conforming  Changes  to Closure Regulations (Secs. 264.113, 265.112 and

265.113)

1. General

2. Clarifications

a. Extension of Closure Deadlines

b. Modification of Closure Plans

3. Closure Plan Information Requirements

N. Conforming Change to Sec. 264.1(g)

VII. Relationship to Other Programs

A. Superfund

1. General

2. Listing RCRA Sites on the National Priorities List (NPL)

3. Use of CERCLA to Supplement RCRA Authorities

B. PCB Spill Policy under TSCA

C. Other Elements of RCRA Subtitle C Program

1. Relationship to Subpart F Ground-Water Corrective Action

2. Land Disposal Restrictions Program

3. Relationship to section 3004(n) Standards

4. Administrative Orders under RCRA section 3008(h)

5. Financial Assurance for Corrective Action

a. Timing

b. Cost Estimation

c. Allowable Mechanisms

D. RCRA Subtitle D: Solid Waste Disposal

E. RCRA Subtitle I: Underground Storage Tanks

F. Federal Facilities



VIII. Public Involvement



IX. State Authorization

A. Applicability of Rules in Authorized States

B. Effect on State Authorizations

1. Schedule and Requirements for Authorization

2. States with Existing Corrective Action Programs

C. Corrective Action and Mixed Waste Authorization



X. Regulatory Impact Analysis

A. Executive Order No. 12291

1. Background

2. Scope and Analytical Approach

3. Potential Scope of the Corrective Action Program

4. Qualitative Analysis

5. Description of Options Analyzed Quantitatively

6. Results of Quantitative Analysis

7. Economic Impacts

8. Federal Facilities

B. Regulatory Flexibility Act

C. Paperwork Reduction Act



List of Subjects



XI. Supplementary Documents

1. Authority



    These  regulations  are  issued  under  the authority of sections 1003,

1006,  2002(a),  3004(u),  3004(v),  3005(c),  and  3007 of the Solid Waste

Disposal  Act, as amended by the Resource Conservation and Recovery Act, as

amended by the Hazardous and Solid Waste Amendments of 1984, 42 U.S.C. 6924

(a), (u), and (v), and 6925(c).



II. Background



    Prior  to  passage  of the Hazardous and Solid Waste Amendments of 1984

(HSWA),  statutory  authorities  and promulgated regulations for compelling

corrective  action at facilities regulated under subtitle C of the Resource

Conservation  and  Recovery  Act  (RCRA) were limited to the following: (1)

Section  7003  of  RCRA,  which  provides EPA enforcement authority to take

action  where  solid  or  hazardous  waste  may  present  an  imminent  and

substantial  endangerment  to  human health or the environment; (2) section

3013  of  RCRA, which provides authority for requiring investigations where

the  presence of hazardous waste or releases of hazardous waste may present

a  substantial  hazard  to  human health or the environment; and (3) 40 CFR

part  264,  subpart  F,  which  provides  a  regulatory  program to address

releases  of  hazardous  wastes  and hazardous constituents to ground water

from ''regulated units.'' (''Regulated units'' are defined in 40 CFR 264.90

as  surface  impoundments, waste piles, land treatment units, and lan fills

which  received  hazardous  waste  after July 26, 1982.) Section 106 of the

Comprehensive  Environmental  Response,  Compensation, and Liability Act of

1980 (CERCLA), provides a broad authority, similar to RCRA section 7003, to

take  abatement  actions  to remediate any actual or potential imminent and

substantial  endangerment  caused  by  actual  or  threatened  releases  of

hazardous substances.



    The  1984  HSWA  amendments  substantially  expanded  corrective action

authorities  for  both  permitted  RCRA facilities and facilities operating

under  interim  status.  Section  3004(u)  of HSWA requires that any permit

issued  under  section 3005(c) of RCRA to a treatment, storage, or disposal

facility  after November 8, 1984, address corrective action for releases of

hazardous  wastes or hazardous constituents from any solid waste management

unit  (SWMU)  at  the  facility.  These  permits  will contain schedules of

compliance  where corrective action activities cannot be completed prior to

permit issuance. In addition, facility owners or operators must demonstrate

assurances   of   financial  responsibility  for  completing  the  required

corrective  actions.  Section  3004(v) authorizes EPA to require corrective

action  beyond  the  facility  boundary  where appropriate. Section 3008(h)

provides  EPA  with authority to issue administrative orders or bring court

action to require corrective action or other measures, as appropriate, when

there is or has been a release of hazardous waste or hazardous constituents

from a RCRA facility operating under interim status.



III. Purpose of Today's Rule



    The  purpose of today's rule is to establish a comprehensive regulatory

framework  for  implementing  the  Agency's corrective action program under

RCRA.  This  rule  defines both the procedural and substantive requirements

associated  with  sections  3004(u)  and  3004(v). While the new corrective

action authorities became effective on their date of enactment (November 8,

1984),  today's  proposed  rule  is  intended  to establish a comprehensive

regulatory  framework  for these statutory authorities. The proposal should

serve  to  promote  national  consistency  in  implementing  this important

component  of  the RCRA {pg 30800} program, and will establish standards to

which  States  seeking  authorization for section 3004(u) corrective action

must  demonstrate  equivalence.  In  addition,  this  rulemaking provides a

procedural vehicle for the regulated community and other interested parties

to comment on the Agency's regulatory intentions for this program.



    The  following sections of this preamble provide a detailed explanation

of  the background and specifics of today's proposed rulemaking. Section IV

discusses  implementation of the corrective action program to date. Section

V  provides  an  overview  of the regulatory program proposed today and the

management  philosophy  which  led  to this proposal. Section VI provides a

section-by-section  analysis of the proposed rule. Section VII examines the

relationship  of today's rule to other environmental programs. Section VIII

discusses  public  involvement  in  the  corrective  action  program, while

section IX provides information on State authorization for the new program.



IV. EPA's Implementation of the Corrective Action Program To Date



    Since  1982,  the  RCRA  program  has  been  implementing the subpart F

corrective  action requirements for releases to ground water from regulated

units  through  permits.  Since  November  1984, the HSWA corrective action

requirements,  which were effective immediately, have been implemented on a

case-by-case  basis  in  individual  facility  permits  or  section 3008(h)

corrective  action  orders. To implement the HSWA corrective action program

to  date,  EPA  has issued several regulations and guidance documents. This

section describes those rules and guidance documents, the current status of

corrective  action  activities  in the permitting and enforcement programs,

and   the  availability  of  technical  guidance  documents  pertaining  to

corrective action.

A. Pre-HSWA RCRA Corrective Action



    EPA's  base  permit  regulations, promulgated under pre-HSWA authority,

establish a program for monitoring and remediating releases to ground water

from  regulated  hazardous waste management units (40 CFR part 264, subpart

F,  discussed below), and reporting of releases from permitted units (under

40  CFR  part  270).  These  regulations were established in 1982 under the

general statutory authority in section 3004(a) of RCRA.



    Under  current subpart F regulations, the corrective action requirement

(Sec.  264.100)  is  the third step of a three-phase program for detecting,

characterizing,  and  responding  to releases to the uppermost aquifer from

regulated  units.  The  first  phase, called detection monitoring, requires

facility  owners  or  operators to monitor ground water at the downgradient

edge   of  the  waste  management  boundary  for  indicator  parameters  or

constituents  that  indicate  the  likelihood of a release. If a release is

detected, the owner/operator tests for all appendix IX (of 40 CFR part 264)

constituents,  and a ground-water protection standard (GWPS) is established

for  every  appendix IX constituent detected above background levels. Under

the  second,  or  compliance  monitoring  phase  of  the  program (which is

triggered when the release is confirmed), the owner/operator is required to

perform  additional investigations to characterize the nature and extent of

contamination.   In   the   third  and  final  stage-corrective  action-the

owner/operator  is  required  to  remove or treat in place all contaminants

present in concentrations above the ground-water protection standard beyond

the compliance point.



    The  ground-water  protection standards established under subpart F are

set  at either the background levels, maximum contaminant levels (MCLs) for

14  specific  constituents,  or alternate concentration limits (ACLs). MCLs

are   contaminant   concentration   levels   which  represent  the  maximum

permissible  level  in  drinking  water  supplies as promulgated by the EPA

under  the  Safe  Drinking  Water  Act.  ACLs are contaminant concentration

levels  determined  by  the Agency to be protective of human health and the

environment based on site-specific circumstances. Proposed revisions to the

existing  subpart F regulations to create a program consistent with today's

proposal  for subpart S are expected to be published shortly in the Federal

Register.  A  discussion  of the relationship between this proposal and the

proposed  amendments  to  subpart  F  is  included in section VII.C of this

preamble.



B. July 15, 1985, Codification Rule (50 FR 28702)



    On  July  15,  1985,  EPA  promulgated  regulations  that  codified the

statutory  language  of the new section 3004(u) corrective action authority

of  HSWA (see 50 FR 28702, 40 CFR 264.90(a)(2) and 264.101). In particular,

the  July  1985  Codification  Rule  amended  40 CFR part 264, subpart F by

adding  new  Sec.  264  101,  which  essentially  reiterated  the statutory

language of section 3004(u).



    In  addition,  the  preamble to the July 1985 Codification Rule defined

the  Agency's  jurisdiction  under  the  new  authorities by interpreting a

number  of  key terms in the statutory language. Specifically, the preamble

discussed  EPA's  interpretations  of the terms ''facility,'' ''solid waste

management  unit,''  and  ''release,''  in  relation  to the new corrective

action  authorities.  (EPA  is  proposing to codify these definitions, with

some  modifications,  in  today's  rule.)  The  preamble  also provided the

Agency's  interpretation  of  the authority conferred on it through section

3008(h),  the  interim  status  corrective  action  authority.  A  detailed

discussion  of the Agency's interpretation of the section 3008(h) authority

was   provided  in  a  December  16,  1985,  guidance  memorandum  entitled

''Interpretation  of  section  3008(h) of the Solid Waste Disposal Act.'' A

copy  of  that  memorandum  may be found in the docket established for this

rulemaking.



C. December 1, 1987, Codification Rule (52 FR 45788)

    On  December  1,  1987,  EPA  issued  a  companion  to  the  July  1985

Codification Rule that further modified the part 264 and part 270 hazardous

waste  management  regulations to implement the new statutory provisions of

HSWA  (see  52  FR  45788).  This Second Codification Rule addressed issues

arising  from the new amendments rather than codifying requirements imposed

directly by the statute. Three elements of that rule relate to the new HSWA

corrective  action  requirements: Permit application requirements for solid

waste  management  units  (SWMUs),  corrective  action  beyond the facility

boundary, and corrective action for injection wells with permits-by-rule.



    The  Second  Codification  Rule  amended  the  existing  part  B permit

application  requirements  of  Sec.  270.14 by adding a new provision (Sec.

270.14(d))  that  requires  certain  information  pertaining to solid waste

management  units  at  the  facility  applying  for  a RCRA permit. The new

provision  requires  descriptive  information on all solid waste management

units at the facility, and all available information pertaining to any past

or  current releases from these units. The provision also requires facility

owner/operators  to  perform  sampling  and  analysis as required by EPA to

assist  in  determining  whether  or  not releases have occurred from solid

waste management units at the facility.



    The  Second Codification Rule also amended Secs. 264.100 and 264.101 of

the  RCRA  part  264  regulations  to  codify section 3004(v) of RCRA. This

statutory provision requires facility owner/operators to address corrective

action  for  releases  that  have  migrated  beyond {pg 30801} the facility

boundary,  unless  the  owner or operator demonstrates to EPA that, despite

his or her best efforts, s/he was unable to obtain the necessary permission

to  undertake  the  required actions (see Secs. 264.100(e) and 264.101(c)).

This  new  provision  applies  to  releases from all solid waste management

units,  including  releases  to the uppermost aquifer from regulated units.

Moreover,  section  3004(v)  makes  it  clear that the provision applies to

certain  interim  status  units  (section  3004(v)(2)), as well as units at

permitted   facilities  (section  3004(v)(1)).  Where  access  to  off-site

property  is denied, EPA may require that certain measures be taken on site

to  mitigate the off-site contamination (e.g., source control measures). As

will be discussed later, EPA is today proposing changes to these regulatory

provisions.



    The Second Codification Rule also included new provisions governing the

implementation    of    corrective   action   requirements   through   RCRA

permits-by-rule  for  Class  I  hazardous  waste injection wells (see Secs.

270.60(b)(3),  144.1(h),  144.31(g)).  Under  40 CFR 270.60, the corrective

action  requirements of Sec. 264.101 must be addressed in order to obtain a

permit-by-rule for a hazardous waste injection well. Since today's proposal

will replace Sec. 264.101, these facilities will be required to comply with

today's  proposed  subpart  S  regulations  in  the  same  manner  as other

facilities which receive permits under section 3005(c) of RCRA.



    The  Second  Codification  Rule also clarified that a Class I hazardous

waste  injection well with a UIC permit issued after November 8, 1984, does

not have a RCRA permit-by-rule until the corrective action requirements are

imposed  at  the  entire  facility.  Further,  the Second Codification Rule

clarified  that a Class I injection well that received a UIC permit retains

interim   status  under  RCRA  until  corrective  action  requirements  (if

necessary) are imposed through a RCRA rider permit.



D. Proposed Rule, Financial Assurance for Corrective Action (51 FR 37854)



    On  October  24,  1986,  EPA  proposed  new amendments to the financial

responsibility  standards  applicable  to owners and operators of hazardous

waste  treatment, storage, and disposal facilities (hereinafter referred to

as  FACA-see  51  FR  37854).  This  proposed  rule  provided  a regulatory

framework  for  implementing  the  statutory requirement of section 3004(u)

(codified  in  Secs.  264.101 and 264.90(a)(2)) for demonstrating financial

assurance for the costs of corrective actions.

    The   1986   FACA  proposal  set  out  a  detailed  set  of  procedures

implementing  the  section  3004(u) financial assurance requirements. These

procedures addressed: (1) The timing of financial assurance demonstrations;

(2)  cost-estimating  procedures, including the periodic adjustment of cost

estimates, for determining the amounts of required financial assurance; and

(3)  permissible  financial  assurance mechanisms, including their required

wording  and  allowable  combinations of mechanisms. EPA is today proposing

specific   language   which  will  clarify  when  financial  assurance  for

corrective action must be demonstrated and when adjustments to the coverage

levels  will  be  required.  With  respect  to all other procedural aspects

associated  with  the  FACA  requirements  (e.g.,  the  set  of  acceptable

mechanisms  or use of a mechanism for multiple financial responsibilities),

EPA  intends  to use the FACA proposal as general guidelines for examining,

on  a  case-by-case  basis,  the  adequacy  of  the  financial  assurances.

Financial  assurance  for  corrective  action  is  discussed  more fully in

section VII.C.5 of this preamble.



E.  National  RCRA  Corrective  Action  Strategy (51 FR 37608) and the RCRA

Corrective Action Outyear Strategy (Fall, 1989)



    In  October  1986, EPA issued a draft ''National RCRA Corrective Action

Strategy''  to  inform  the  Regions,  States, regulated community, and the

public  of  the Agency's overall plans for implementing the HSWA corrective

action   authorities.  The  Strategy  provided  an  overview  of  the  HSWA

corrective  action  authorities and the universe of RCRA facilities subject

to  these  authorities,  and  described  the basic process for identifying,

investigating,  and  remediating  releases  at  RCRA  facilities.  It  also

discussed  the  Agency's  plans  for establishing priorities for corrective

action,  the  relationship  between permitting and enforcement authorities,

factors   influencing   the   management  of  corrective  action,  and  the

relationship between EPA and the States in implementing this program.



    The Agency received a number of comments on the draft strategy, many of

which  are  reflected  in  the  content  of  today's proposed rule. Today's

proposal,  which  addresses  in  detail  most  of the elements of the draft

strategy, effectively finalizes the strategy.



    Although  some  portions  of  the  draft strategy, such as the Agency's

plans for prioritizing RCRA facilities for corrective action, are not fully

addressed  in  today's  proposal,  they are the subjects of recommendations

contained  in the RCRA Corrective Action Outyear Strategy (CAOS), published

in  the  Fall  of 1989. These recommendations outline a management approach

for  the  corrective action program that is realistic and workable in light

of  the  many  challenges that EPA and the States will face in implementing

this  program  over  the  next  several  years.  While  some  of  the  CAOS

recommendations  can  be  directly implemented, others will be addressed in

detail in forthcoming guidance.



F. Implementation of the HSWA Corrective Action Program



    To implement the corrective action program to date, EPA has developed a

general  process  to  assure  that  actions taken are commensurate with the

problem  presented. In this process, each stage serves as a screen, sending

forward  to the next step those facilities or units at a facility which the

Agency  has  found  to be a potential problem, and eliminating from further

consideration  units  and  facilities  where  the  Agency has discovered no

current  environmental  problem.  The  Agency intends to provide sufficient

flexibility in this process to facilitate timely abatement of environmental

problems.



    RCRA  facilities  are  generally  brought  into  the  corrective action

process  at the time the Agency is considering a permit application for the

facility,  or  when  a  release  justifying action under section 3008(h) is

identified.  The  process  begins  with  an  Agency-conducted RCRA Facility

Assessment   (RFA),   which  is  analogous  to  the  Superfund  Preliminary

Assessment/Site  Investigation  (PA/SI).  The  RFA includes: (1) A desk top

review  of  available information on the site; (2) a visual site inspection

to  confirm  available  information  on solid waste management units at the

site  and to note any visual evidence of releases; and (3) in some cases, a

sampling  visit,  to  confirm  or  disprove  suspected  releases. If, after

completion  of  the RFA it appears likely that a release exists, the Agency

typically develops a schedule of compliance, to be included in a facility's

RCRA  permit,  for further studies and actions the permittee must undertake

to  fulfill the responsibilities imposed by section 3004(u). Alternatively,

the  Agency  might  issue  an  order  pursuant to section 3008(h) to compel

corrective action.



    The  second stage of the corrective action process is the RCRA Facility

Investigation  (RFI).  The RFI is undertaken when a potentially significant

release  has been identified in the RFA; its purpose is to characterize {pg

30802}  the  nature  and extent of contamination at the facility, and it is

analogous  to  the  Remedial  Investigation  (RI)  process of the Superfund

program. Typically, the RFI will be focused on specific concerns identified

in  the  RFA  and  will  be  staged to avoid unnecessary analysis. When the

Agency  determines,  on the basis of data generated during the RFI or other

information,  that  cleanup  is  likely to be necessary, the owner/operator

will  be required to conduct a Corrective Measure Study (CMS) to identify a

solution  for  the  problem at the site. Once the Agency selects the remedy

for  the  facility, the Agency will either issue a followup section 3008(h)

order  (in  the  case of an interim status facility), or modify the permit,

and  the  remedy  will  be  implemented  by  the owner/operator with Agency

oversight.



    In certain situations, the Agency may require an ''interim measure'' at

the  facility  without waiting for the final results of the RFI or the CMS.

Interim  measures  are  actions required to address situations which pose a

threat   to   human  health  or  the  environment  or  to  prevent  further

environmental  degradation or contaminant migration pending final decisions

on  required  remedial  activities.  Superfund  generally  uses the removal

authority  provided  under  section  104  of CERCLA to accomplish this same

objective where expedited response and/or emergency actions are needed.



    Currently,  implementation  of  the  corrective action program is being

undertaken  by  EPA,  with  assistance from State agencies. Six States have

been authorized to date to implement the HSWA corrective action program.



    The  general  corrective  action  process  described  above  is carried

forward  in  today's  proposal. However, today's proposal will describe the

requirements  in greater detail, and will provide the public an opportunity

to comment on this approach.

    More  detailed  information  about each of the phases of the corrective

action  program  as  implemented  to  date  can  be  found  in the guidance

documents  referenced  below.  Additional guidance will be developed in the

future.



    1.  RCRA  Facility  Assessment  Guidance  (Final,  October, 1986). This

document  can  be  obtained  through  the  National  Technical  Information

Services  (NTIS),  5285  Port  Royal  Rd., Springfield, VA- (703) 487-4650.

Document Number PB87-107769.



    2. RCRA Facility Investigation Guidance (Interim Final, May, 1989). For

further information, contact: Jon Perry-(202) 382-4663.



    3.  Corrective  Action  Plan  (Interim  Final,  May, 1988). For further

information, contact: (202) 382-4460.



    4.  Interim  Measures  Guidance (Interim Final, May, 1988). For further

information, contact: Tracy Back- (202) 382-3122.



V. Approach to Corrective Action in Today's Rule



    Together  with  the National Contingency Plan (NCP), which EPA recently

promulgated  (March  8,  1990,  55 FR 8666), today's proposal defines EPA's

overall  approach  to  the cleanup of environmental contamination resulting

from  the mismanagement of hazardous and solid waste. Today's proposal will

establish  a  regulatory  framework  for  corrective  action  under section

3004(u)  of  RCRA  and will provide guidelines for corrective action orders

imposed  through  administrative  orders  under  section  3008(h)  of RCRA.

Substantive  provisions  of  the  rule, when promulgated, generally will be

applicable to response actions under CERCLA involving releases of hazardous

waste  (including  hazardous  constituents).  These  provisions may also be

''relevant and appropriate'' to other CERCLA response actions.



    This section of the preamble briefly summarizes EPA's basic approach to

RCRA  corrective  action, the fundamental cleanup goals of the program, and

the major elements of today's rule.



A. Priorities and Management Philosophy for RCRA Corrective Action



    Approximately  5,700  facilities  are  currently in the RCRA subtitle C

universe,  and  therefore  are  potentially  subject  to  corrective action

requirements.  These  facilities  are  likely, together, to have as many as

80,000  SWMUs.  Many  of  these facilities, EPA believes, will require some

level  of  remedial  investigation and corrective action to address past or

current releases.



    The  level  of investigation and subsequent corrective action will vary

significantly   across   facilities.  This  regulation  would  ensure  that

variation  can  be  accommodated by recognizing that the necessary scope of

investigations  and  studies  may be different depending upon the situation

presented.  It  is the Agency's intention that State and Regional personnel

have the ability to require investigations sufficient to fully characterize

the  facility  and assess necessary actions. In many cases the problem will

pose less risk or be less complex than a major Superfund site listed on the

National  Priorities List. Therefore, the Agency expects that, for the most

part,  RCRA  cleanups  will  be  less complex and less expensive than those

under  CERCLA,  and  less  detailed  study will be required before remedial

action  begins. In some cases, however, the Agency also recognizes that the

situation  could  be  comparable  to  that  of a major CERCLA site. In such

cases,  the  Agency  will  require more detailed analysis and more rigorous

oversight.  There  will  also  be cases where immediate action is required,

while  at many other sites, current exposure will be limited and action can

be  safely  deferred.  Not  only  will  the nature of cleanup required vary

widely,   but   so   too   will   the   characteristics   of  the  facility

owner/operators.  Some  facilities  will be sites controlled by financially

viable owner/operators, while others will be weak financially; some will be

under active long-term management, but at others the owner/operator will be

seeking  to  leave the site; some will be simple facilities with one or two

storage  tanks,  yet  others will be major complexes, such as large Federal

facilities, with thousands of solid waste management units.



    Because of the wide variety of sites likely to be subject to corrective

action,  EPA  believes  that  a  flexible  approach, based on site-specific

analyses,  is  necessary.  No  two  cleanups  will  follow exactly the same

course,  and therefore the program has to allow significant latitude to the

decision  maker  in  structuring  the  process,  selecting  the remedy, and

setting cleanup standards appropriate to the specifics of the situation. At

the  same  time,  a  series  of  basic  operating  principles  guide  EPA's

corrective action program under RCRA. These principles, which are reflected

in today's proposal, are described briefly below.



    In  managing  the  corrective action program, the Agency will place its

highest   priority  on  action  at  the  most  environmentally  significant

facilities and on the most significant problems at specific facilities. EPA

is committed to directing its corrective action resources first to the most

environmentally  significant problems. The level of threat posed by each of

the  5,700  facilities  now subject to corrective action varies widely-some

are  a  major  concern  and  require  prompt attention; others will require

eventual  cleanup  but do not currently pose a threat; still others have no

significant releases and will not require corrective action at all. At some

of  these  facilities,  EPA  will  automatically  address corrective action

because  of its permitting priorities. Under HSWA, statutory deadlines were

established for issuance of RCRA {pg 30803} permits to the various types of

treatment, storage, and disposal facilities. Each of these permits must, to

the  extent  necessary,  require  a  schedule  of compliance for corrective

action. However, a substantial universe of facilities that will not receive

permits  must  also  be  addressed  for corrective action. EPA, through its

Environmental  Priorities  Initiative,  will  review and set priorities for

action  among  these  facilities,  to  ensure  that  it  addresses the most

significant first.



    It  will  also  be  important  for  EPA to set priorities and focus its

efforts   within   facilities  undergoing  corrective  action  through  the

permitting  process.  Facilities  receiving  permits  will present the full

range of remedial problems; EPA and authorized States must carefully manage

their  resources at these facilities to ensure that the program effectively

focuses  on the most pressing problems. The Agency's first priority will be

to  require interim measures to address sites posing an immediate threat to

human  health  and  the  environment, and to pursue engineering remedies to

control  or  eliminate  further  migration  of  environmental  releases. In

addition,  the  Agency  will  expect  prompt remediation of all significant

off-site  contamination,  regardless  of  whether  human  or  environmental

exposure  to  the  contamination is currently occurring. On the other hand,

sites  where  current  exposure  is  low and releases have been effectively

controlled  will be a lower priority. This is particularly likely to be the

case  where a site is controlled by a financially viable owner/operator who

can  ensure  that releases are adequately contained and exposure eliminated

and who will be capable of undertaking eventual cleanup.



    The  Agency  may rely on ''conditional'' remedies where prompt remedial

action  can  reduce  risk  to  levels acceptable for current uses, or where

final  cleanup  is impracticable. As a general principle, EPA believes that

cleanups  must  achieve  a  level appropriate for all actual and reasonably

expected uses (The question of cleanup goals is discussed more fully in the

next  section  of  this preamble.) RCRA sites subject to corrective action,

however,  will  typically be facilities seeking permits to manage hazardous

waste,  rather than sites that are widely open to the public and subject to

a  broad  range of uses. As long as the permit is in place and the facility

is  under  the  management  of the owner/operator, exposure to contaminated

media  within  the  facility boundary, such as contaminated soils, would be

significantly  less  than  it  would  be in an area of unrestricted access,

where future uses might include residential or agricultural development. In

such  controlled  use  situations,  EPA  believes  that  it  will  often be

reasonable to require prompt cleanup to levels consistent with current use,

but  to  defer  final cleanup as long as the owner/operator remains under a

RCRA permit.



    In  other  cases,  it may be readily apparent that cleanup of a site to

levels  appropriate  for  unrestricted use will be impracticable. RCRA will

have  to  address  a number of intractable problems, such as the cleanup of

large,  complex  sites  like  municipal  landfills, or ground-water cleanup

where  the  bedrock is heavily fractured. In these cases as well, it may be

appropriate  to  rely  on ''conditional'' remedies that control risk during

the  life  of  the  permit,  and  rely on institutional controls to prevent

future exposure.



    EPA  expects  that  these  conditional remedies will play a significant

role  in  the implementation of RCRA corrective action, and will enable the

Agency   and   the  regulated  community  to  focus  their  resources  most

effectively   on   the   most  pressing  problems.  Further  discussion  of

''conditional'' remedies is contained in section VI.F.8 of this preamble.



    The  Agency  intends  to remove regulatory disincentives to independent

action  by  facility owner/operators and will encourage voluntary cleanups.

EPA recognizes that it is important to allow willing and responsible owner/

operators   to   begin   corrective  action  promptly  without  unnecessary

procedural  delays. In many cases, the Agency believes that owner/operators

will  wish  to take source control measures, begin ground-water pumping, or

take  other measures to reduce or eliminate a problem. EPA encourages these

activities,  and  in  many  cases  may  find  it appropriate to incorporate

owner/operator.   initiated  corrective  action  into  permits  as  interim

measures.  In  addition, the Agency has taken steps to simplify RCRA permit

modification  procedures  for  corrective  action in its final rule on RCRA

permit  modifications  (53  FR  37912,  September  28,  1988). The issue of

voluntary corrective action is discussed more fully in section VI.A of this

preamble.



    Facility investigations and other analyses will be streamlined to focus

on  plausible  concerns  and  likely  remedies,  and  to  expedite  cleanup

decisions.  While  remedial  investigations  must  be  thorough  enough  to

identify  any  serious  problems, EPA recognizes that its own resources and

those  of  the  regulated  industry  are  finite,  and therefore that these

investigations  must  be  focused  on plausible concerns and conducted in a

step-wise   fashion,  with  early  screens  to  determine  whether  further

investigation  is  necessary.  Similarly,  although it will be necessary in

some  cases-particularly  at  facilities  with  large  and  complex cleanup

problems-for  the  owner/operator  to  analyze  a  wide  range  of  cleanup

alternatives,  at  most  RCRA  facilities  a  more limited analysis will be

appropriate.  For  example,  when  the  appropriate  remedy is self-evident

(e.g., drum removal and treatment to best demonstrated available technology

(BDAT)),  it  may be unnecessary to evaluate alternatives that would not be

adopted.  Similarly,  where  an  owner/operator  proposes  a remedy that is

effective  and  protective, it may be appropriate to approve the remedy and

avoid  continued  studies that would serve only to delay cleanup. In either

case,  the  permit  would  establish  performance  standards in the form of

cleanup  levels.  If the remedy failed to achieve these standards, it would

have  to  be modified accordingly. Section VI.H.5 of the preamble discusses

in  further detail the issue of the technical impracticability of achieving

a remedial requirement given a specified remedy.



    In  managing  the  corrective action program, the Agency will emphasize

early  actions  and  expeditious  remedy  decisions.  One  of  the Agency's

overriding  goals  in  managing  the  corrective  action program will be to

expedite  cleanup  results  by  requiring sensible early actions to control

environmental  problems  on  an  interim  basis,  and  using  flexible  and

pragmatic approaches in making final remedy decisions. EPA believes that in

many  cases  it will be possible to identify early in the corrective action

process  actions  which  can  and  should  be  taken to control exposure to

contamination, or to stop further environmental degradation from occurring.

Such interim measures may be relatively straightforward, such as erecting a

fence  or  removing  small  numbers of drums, or may involve more elaborate

measures  such  as  installing  a  pump and treat system to prevent further

migration  of  a ground- water contaminant plume. In another example, where

it  is  obvious  that  the  eventual  remedy  will  require  excavation and

treatment  or  removal  of contaminated ''hotspots,'' such action should be

initiated as an interim measure, rather than deferring it until after final

remedy selection.



    Final  remedy  decisions  must  be based on careful judgments and sound

technical   information.   However,  today's  proposed  rule  provides  for

considerable  flexibility  in  structuring studies and {pg 30804} selecting

remedies.  It  is EPA's intention to use that flexibility to streamline the

remedy  development/decision  process whenever feasible. Corrective Measure

Studies should focus on plausible remedial options, and should be scaled to

fit  the  complexity  of the remedial situation. Obvious remedial solutions

should not be impeded by unnecessary studies. Voluntary cleanup initiatives

by  owner/operators  that  are  consistent with EPA's cleanup goals will be

encouraged as a means of expediting the remedial process.



B. Cleanup Goals for Corrective Action

    EPA's  goal in RCRA corrective action is, to the extent practicable, to

eliminate  significant releases from solid waste management units that pose

threats  to  human health and the environment, and to clean up contaminated

media  to  a level consistent with reasonably expected, as well as current,

uses.  The  timing  for  reaching  this  goal  will  depend on a variety of

factors, such as the complexity of the action, the immediacy of the threat,

the  facility's priority for corrective action, and the financial viability

of  the owner/operator. However, the final goal of cleanup would remain the

same.



    It  should  be  recognized  that  EPA's  emphasis  in  today's  rule on

minimizing  further  releases  means that corrective action will frequently

require  source  removal,  source  control,  and  waste  treatment. In this

respect,  today's  rule  reflects  a  shift  in  emphasis from current RCRA

corrective  action  requirements  for  ground-water releases from regulated

units.  These  requirements currently focus on cleanup of the ground water,

but  not  on  control  of  the  source.  However, EPA believes that it will

frequently  be  impossible  to  control  releases  and ensure the long-term

effectiveness  of remedies without significant source control. For example,

a  response action that focuses entirely on remediation of the contaminated

medium  may  meet  acceptable  cleanup  standards  in  the  short term, but

continued  leaking could lead to unacceptable releases in the future as the

source  continues  to leak. Therefore, today's rule explicitly provides EPA

authority to require source control.



    One  of  the  more controversial issues related to corrective action is

the  cleanup  goals  for contaminated media, or ''how clean is clean.'' EPA

has  not  attempted in this rule or elsewhere to establish specific cleanup

levels  for  different  hazardous constituents in each medium. Instead, EPA

believes  that  different  cleanup  levels will be appropriate in different

situations,  and that the levels are best established as part of the remedy

selection  process. Generally. however, the cleanup must achieve protective

levels  for  future  as well as current uses. This is the approach taken in

today's proposal.



    To  be ''protective'' of human health, EPA believes that cleanup levels

for  carcinogens  must  be  equal to or below an upperbound excess lifetime

cancer  risk  level of 1 in 10,000 (1X10sup -4). As proposed today, cleanup

levels  would be selected within the upper bound 1X10sup -4'' to 1X10sup -6

risk range during the selection of remedy process; however, remedies at the

more  protective  end  of the range would ordinarily be preferred. For non-

carcinogens,  cleanup  levels  would  be  set  at  a level at which adverse

effects would not be expected to occur. The application of this approach to

specific media is described below.

    Ground water. Potentially drinkable ground water would be cleaned up to

levels  safe  for drinking throughout the contaminated plume, regardless of

whether  the  water  was  in fact being consumed. Where maximum contaminant

levels  (MCLs)  established under the Safe Drinking Water Act are available

for  specific contaminants, these limits generally will be used; otherwise,

the  levels  would  be  set within the protective range. Alternative levels

protective  of the environment and safe for other uses could be established

for  ground  water  that  is not an actual or reasonably expected source of

drinking water.



    Soil.  Contaminated  soil would be remediated to levels consistent with

plausible  future  patterns  of  use.  For example, where access to an area

would  be  unrestricted,  cleanup  would  generally  be  required to levels

appropriate  for  residential  development.  At  industrial  sites or sites

dedicated   to  long-term  hazardous  waste  management,  cleanup  to  less

stringent  levels  might  be  appropriate,  although institutional controls

could be necessary to ensure that the use pattern did not change.



    Surface water. Releases to surface water should be remediated to levels

consistent  with  potential  uses.  For  example,  where  surface  water is

designated  for  drinking  water  or  is a potential drinking water source,

cleanup  to  drinkable  levels  would  be  required. In the case of surface

water,  environmental  effects  are  likely  to  be particularly important,

because  levels  protective  for  humans  may  often  be  insufficient  for

protection of aquatic organisms.



    Air. Like soil, air releases from solid waste management units would be

of  concern  where  they  posed a threat to humans or the environment under

plausible  current  or  future  use  patterns. Typically, corrective action

involving  air  concerns  would  involve source control to minimize further

releases.



C. Major Elements of Today's Proposal



    The  principles  described  above  will shape EPA's general approach to

corrective  action,  and they serve as operating assumptions behind today's

notice.  Today's  proposal  will  establish  the  basic  framework  for the

corrective  action  program,  both  for  EPA  and  authorized  States. More

specifically,  it  codifies  the  procedures  for  identifying problems and

selecting remedies at RCRA facilities; the standards for cleanup, including

the  establishment  of  cleanup  levels;  and  the  standards  for managing

cleanups  and  the  wastes generated by cleanups. The major elements of the

proposal are summarized below.

    Permitting  procedures  and  permit  schedules  of  compliance. Today's

proposal,  which implements section 3004(u), addresses corrective action at

facilities  seeking  RCRA  permits.  Corrective action requirements will be

imposed  on  these  facilities  directly through the permitting process and

will   be  incorporated  into  permits  through  schedules  of  compliance.

Typically,  before  a  permit  is  issued, EPA or an authorized State would

conduct  an  RFA  at  the facility to determine whether a potential problem

existed.  Where  a  likely  release  was  found, the permit would contain a

schedule  of compliance, as specified in proposed Sec. 264.510, requiring a

remedial  investigation  focusing  on  the specifics of the likely release.

This  schedule  of  compliance  would be a part of the permit, and would be

successively  modified,  as necessary, as studies and corrective actions at

the facility proceeded.



    Trigger  or ''action levels.'' Where contamination is identified during

the  facility investigation, EPA or an authorized State will have to make a

decision  on  whether  further  analysis,  including  analysis of potential

remedies,   is   appropriate,   or  whether  the  contamination  is  at  an

insignificant  level. For this reason, the rule incorporates the concept of

''action  levels''-levels that, if found in the environment, will typically

trigger  a  Corrective Measure Study. Under today's proposal, action levels

would  be  established  in the initial permit, or, in some cases, through a

permit modification after a release has been identified.



    Section  264.521  of the proposal establishes the general principles by

which  action  levels  would be established for each medium. To provide {pg

30805}  guidance for RCRA permit writers, industry, and the public, today's

proposal  includes  in  Appendix  A of this preamble values that the Agency

believes  may  be  appropriate  as  action levels for a number of hazardous

constituents  in  different  environmental  media.  These  levels  would be

incorporated individually into permits through the permitting process.



    If  environmental  levels  were found to be below the action levels, no

further  action  would  ordinarily  be required. However, even if an action

level  has  been  exceeded,  the  proposal  in Sec. 264.514 would allow the

owner/operator to demonstrate that no action was necessary. For example, if

ground  water were not a potential source of drinking water because of high

levels of natural contamination, an owner/operator might successfully argue

that  cleanup  was unnecessary. In this way, action levels would constitute

rebuttable  presumptions. This issue is discussed in more detail in section

VI.E.2 of this preamble.



    Corrective  Measure Study and remedy selection. Typically, if an action

level  has  been  exceeded,  the  facility owner/operator would be required

under the proposal to conduct a Corrective Measure Study (CMS). The purpose

of  the CMS is to identify and evaluate potential remedies. EPA anticipates

that,  in  a  few  cases,  owner/operators  of  larger  sites  with complex

environmental  problems  may  need to evaluate several alternative remedial

approaches in determining the most appropriate remedy for the facility. For

most  RCRA  facilities,  however,  it  will  be  possible to abbreviate the

analysis,  and  frequently  it may be appropriate for the owner/operator to

propose  a  single  alternative, which EPA would approve or disapprove. The

proposed  regulation  in  Sec.  264.522  gives  the  Agency  the  necessary

flexibility to vary the scope of the Corrective Measure Study, depending on

the specifics of the situation.



    EPA would approve or select the remedy under the standards and criteria

proposed in Sec. 264.525. Proposed Sec. 264.525(a) would require the remedy

to  be  protective  of  human  health and the environment, to achieve media

cleanup  standards,  to  minimize  further  releases,  and  to  comply with

subtitle  C  and other waste management standards. In selecting the remedy,

the  Agency  would be required to consider a wide range of factors, such as

the  remedy's  short-  and  long-term effectiveness and its practicability.

These  factors  are  generally  comparable to the factors considered by the

Agency  in selecting Superfund remedies under Sec. 300.430 of the NCP. (See

55 FR 8666, March 8, 1990.)

    Remedies  selected  under  Sec.  264.525  would  require  formal permit

modifications,  with  opportunity  for public comment and rights of appeal.

After  public  comment, the proposed permit schedule of compliance would be

amended,  (if  necessary)  and approved, to require that the owner/operator

develop a specific remedial design and, after approval of the design, carry

out the remedy.



    Cleanup  levels.  The Agency's goal is that remedies clean up to levels

determined  to  be  protective  of  human health and the environment. EPA's

general  cleanup  goals  are  described  in  section B above and in section

VI.F.5 of this preamble. Specific levels for each facility, consistent with

these  goals,  would be established during the remedy selection process and

would  be  incorporated  into  the  permit  and  made  available for public

comment.



    Where  protective  levels  could  not be attained, or where wastes were

left  on  site  in  disposal  units, long-term management would be required

through the permit.



    Standards  for  management  of  corrective action waste. Proposed Secs.

264.550-264.552  would establish standards for conducting corrective action

and  handling  wastes  generated  during  corrective  action. If corrective

action  waste  meets  the  RCRA regulatory definition of hazardous it would

have to be handled under the proposal as hazardous waste. With some limited

exceptions,  new  units  built  to  treat,  store, or dispose of this waste

on-site would have to comply with 40 CFR part 264 performance standards for

hazardous  waste  units.  Similarly, hazardous waste shipped off site would

have to be sent to RCRA subtitle C facilities.



    The  rule  would  also  establish more flexible standards for temporary

treatment  and  storage  units  developed  during  the course of corrective

action.



    Completion   of   remedy.   Proposed   Sec.   264.530  would  establish

requirements   for   remedy   completion.  Similar  to  RCRA  closures,  an

independent  engineer or other qualified professional would have to certify

completion of the remedy, and, in addition, public notice and comment would

be  required  before the Agency made a final decision on whether the remedy

had been completed.



    In  some cases, it might become clear in the course of a remedy that it

was  not  technically  practicable to reach the cleanup levels specified in

the  permit. In this case, proposed Sec. 264.531 would allow termination of

the  remedial  action  and  waiver  of  the  cleanup  standard. However, if

environmental  contamination  remained  at  unprotective  levels, long-term

institutional  or  other  controls  would  be required to prevent human and

environmental exposure.



    These  requirements  and  alternatives  that  the Agency considered are

discussed in more detail in the following sections.



VI. Section-by-Section Analysis



A. Purpose/Applicability (Section 264.500)



    1.  Conforming  Changes  to  Previous  Codification of Sec. 3004(u) and

General  Discussion. In today's proposal, EPA is establishing a new subpart

S  to  40  CFR  part  264. This section of the proposed rule sets forth the

general applicability of the proposed subpart S regulations. The procedures

and  technical  requirements  of  subpart S apply to any facility seeking a

permit under section 3005(c) of RCRA.



    The  language of Sec. 264.500(a) through Sec. 264.500(d) reiterates the

statutory  language  of section 3004(u) and section 3004(v). Proposed Secs.

264.500  (b),  (c),  and  (d)  have  already  taken  effect as a final rule

following public notice and comment, and are codified at 40 CFR 264.101 (on

July  15,  1985, 50 FR 28702; and December 1, 1987, 52 FR 45788). It is not

the  Agency's intention to reopen for public comment the substance of these

pre-  existing  provisions.  The  Agency  seeks  comment  only on the minor

language  changes  reflected  in  Sec.  264.500  (e.g.,  compare  the first

sentence  of  Sec.  264.101(b) with the first sentence of Sec. 264.500(c)),

and  its  proposal  to  move  these  provisions  from  Sec. 264.101 to Sec.

264.500.



    Proposed Sec. 264.500(a) clarifies that subpart S applies to corrective

action   for   all  SWMUs,  including  regulated  units  (defined  in  Sec.

264.90(a)(2)  as  any  landfill,  surface  impoundment, waste pile, or land

treatment  unit  that  received  hazardous  waste  after  July  26,  1982).

Corrective  action  for  releases  to  ground water from regulated units is

currently   governed   by  Sec.  264.100.  Subpart  S  will  apply  to  the

investigation  of  releases  to  ground water from other SWMUs. Releases to

other  media  (air,  soil and surface waters) from both regulated units and

other SWMUs will also be governed by subpart S.



    The  Agency  intends  to  modify  the  Sec.  264.100  standards  to  be

consistent with the applicable sections of subpart S. Thus, regulated units

and  other SWMUs would be subject to the same standards for identifying and

{pg 30806} implementing necessary remedial action. However, regulated units

will continue to be subject to slightly different standards for identifying

and  confirming  unacceptable  releases  to ground water. EPA believes that

this  distinction  between regulated units and the larger universe of SWMUs

is justified by the slightly different function of investigating procedures

in  the  context  of  regulated  units;  the  purpose  of  the ground-water

detection  and  compliance  monitoring  programs  in subpart F is primarily

preventive, rather than essentially responsive like the subpart S program.



    The  statutory  language  of section 3004(u), repeated in Secs. 264.500

(b)  and  (c),  allows  EPA  to  issue  a  RCRA  permit  with a schedule of

compliance  for  investigating  and  correcting releases, rather than delay

issuance  of  the  permit until cleanup has been completed. This will allow

more  prompt  permitting  both  of interim status facilities, bringing them

under  the  more  stringent  40  CFR  part 264 standards sooner, and of new

facilities,  allowing  more  rapid  expansion  of  treatment,  storage, and

disposal capacity.



    Schedules  of  compliance,  which  are  enforceable  components  of the

permit,  will  thus  be  the  primary vehicle by which EPA will specify the

procedural  and  technical requirements that owner/operators must follow to

achieve  compliance with their subpart S responsibilities. EPA is proposing

specific   procedural  requirements  for  corrective  action  schedules  of

compliance,  including  requirements  associated  with modifications to the

schedules,  in  today's  rule as amendments to the existing 40 CFR part 270

permit regulations.



    As  specified  in  proposed Sec. 264.500(b), subpart S regulations will

apply  to all facilities seeking permits under subtitle C of RCRA (with the

exception  of the specific permits identified in proposed Sec. 264.500(f)).

Permits  subject  to  subpart  S  include  post-closure permits, as well as

permits  issued to operating hazardous waste management facilities. Further

discussion  of  the  applicability  of post-closure permit requirements and

their relationship to section 3004(u) corrective action is discussed in the

preamble to the Second Codification Rule (December 1, 1987, 52 FR 45788).



    2.  Exceptions to Applicability. Today's proposed Sec. 264.500(f) lists

four types of RCRA ''permits'' to which the subpart S regulations would not

apply. Each is discussed below.



    a.  Permits for Land Treatment Demonstrations. Current RCRA regulations

for  hazardous  waste  land  treatment  units  (see Sec. 270.63(a) and Sec.

264.272)  provide for a two-phased permit process in certain circumstances.

A ''permit'' can be issued to a facility with permit conditions which cover

only  the  activities  needed  to  demonstrate  that  the  hazardous  waste

constituents can be completely degraded, transformed, or immobilized in the

treatment  zone.  Such  a  permit  does not address the full RCRA standards

(e.g.,  financial assurance, general facility standards) that apply to land

treatment  facilities.  In the absence of permit conditions addressing full

RCRA  facility  standards,  this  first-phase  demonstration  permit is not

considered  a  full RCRA permit issued under the authority of section 3005.

Once  the  demonstration is successfully completed and the actual operating

permit  (i.e., second part of the two-phased permit) for the land treatment

unit is issued, the subpart S corrective action requirements will apply.



    b.  Emergency  Permits. Section 270.61 of the RCRA regulations provides

for issuance of emergency permits, not to exceed 90 days in duration, where

immediate actions that involve treatment, storage, or disposal of hazardous

waste  are  necessary  to  protect  human  health  and the environment. The

emergency permit provision was included in the RCRA regulations as a way to

provide  a  mechanism  for responses by an owner/operator in true emergency

situations  which  could  not  be delayed until a full RCRA permit could be

issued. In some cases, emergency permits can be issued orally when followed

by  a written permit within a specified time frame. EPA does not believe it

is  appropriate to apply subpart S requirements to emergency permits, since

such  a  requirement  would render this permit mechanism unworkable for the

quick-  response  situations  it  was designed to address. If a facility is

required  to  continue  to operate under a RCRA permit beyond the allowable

time limit for emergency permits, a full operating permit would be required

and the facility would be subject to subpart S requirements.



    c.  Pemits-by-Rule for Ocean Disposal Barges or Vessels. Ocean disposal

barges  and  vessels  are  regulated primarily under the Marine Protection,

Research  and  Sanctuaries Act (MPRSA). The applicable RCRA regulations (40

CFR  270.60(a)) provide that operation of vessels accepting hazardous waste

for  ocean  dumping  are deemed to have a RCRA permit if they have obtained

and  comply with an ocean dumping permit issued under the MPRSA, and comply

with  certain  RCRA  administrative  requirements.  The RCRA permit-by-rule

functions  primarily  to ensure that certain administrative requirements of

the   RCRA  system-in  particular,  waste  manifest  requirements-apply  to

owner/operators  of  such  vessels.  Furthermore,  as of November 1988, the

Ocean  Dumping Ban Act has in effect banned the ocean dumping of industrial

waste.  While  corrective  action  requirements under subpart S do apply to

underground injection control (UIC) facilities and publicly-owned treatment

works  (POTWs) with National Pollutant Discharge Elimination System (NPDES)

permits   subject  to  RCRA  permits-by-rule  under  40  CFR  270.60,  such

requirements  are  necessary  to ensure that corrective action requirements

apply to releases from all solid waste management units at these facilities

not  regulated under other laws. MPRSA permits, however, cover all portions

of  ocean-dumping  vessels. (Any onshore storage or treatment facility that

may be associated with the ocean disposal operation is required to obtain a

separate  RCRA permit.) Thus there are no unregulated units within an ocean

dumping  barge  ''facility.''  Furthermore, unauthorized releases from such

vessels  are subject to regulation under the MPRSA. EPA does not believe it

is  appropriate to apply subpart S to these vessels because the substantive

requirements  of  section 3004(u) of RCRA are already effectively satisfied

by MPRSA requirements.



    d.  Research,  Development  and  Demonstration  Permits.  EPA  does not

believe  that RCRA requires the application of section 3004(u) requirements

to facilities seeking a research and development demonstration permit under

section 3005(g) of RCRA. The conference report on section 3004(u) expressly

states  that  the  provision  is  intended to apply to facilities seeking a

permit  under  section  3005(c)  of RCRA. Accordingly, facilities seeking a

permit  under  section  3005(g)  would  not automatically be encompassed by

section  3004(u). Moreover, the reading of section 3004(u) suggested by the

conference  report  is  supported  by  the  statutory  language  of section

3005(g).  Section 3005(g)(1) provides that the Regional Administrator shall

include such terms and conditions in research and development demonstration

permits   as   s/he  deems  necessary  to  protect  human  health  and  the

environment,   including   provisions   related  to  monitoring,  financial

responsibility  and  remedial  action.  Section 3005(g)(1) further provides

that  these  provisions may be established case-specifically in each permit

without  the establishment of {pg 30807} separate regulations. Accordingly,

the  plain  language  of section 3005(g)(1), and the legislative history of

section  3004(u)  both  suggest that research and development demonstration

permits  can  be subject to case-specific remedial conditions in the permit

as  determined  to  be  necessary,  and  need not be subject to the general

corrective action regulations developed under section 3004(u).



    3.  Voluntary Corrective Action. Today's proposal for corrective action

under  the  authority  of  RCRA  section 3004(u) applies to RCRA facilities

which  are  seeking permits under RCRA subtitle C. Certain facilities where

RCRA  hazardous  wastes  are  present,  and  where corrective action may be

needed,  are not required to obtain subtitle C permits, and, therefore, are

not  subject  to  today's  rule.  For  example,  facilities  which generate

hazardous  wastes and accumulate and store the wastes on site for less than

90 days prior to shipment to another facility are not subject to permits or

to today's proposed rule.



    In a number of cases, owner/operators not subject to a RCRA permit have

expressed  an  interest  in proceeding with corrective action in an attempt

either  to reduce their liability or to preclude subsequent Agency or State

actions.  Some  activities conducted during voluntary corrective action may

require  a  permit if hazardous waste is involved (e.g., excavated waste is

placed into a disposal unit or stored on site for more than 90 days).



    Current  regulations, however, provide significant flexibility for non-

permitted  facilities to undertake corrective action without a RCRA permit.

For  example, 40 CFR 262.34 allows generators to accumulate hazardous waste

on  site  in  tanks  or  containers  for  up to 90 days without a permit or

interim  status, as long as certain conditions- most importantly compliance

with  tank and container standards of 40 CFR part 265-are met. In addition,

this  authority  allows generators to treat hazardous waste in tanks during

the  accumulation period. Under RCRA regulations, a facility owner/operator

conducting  voluntary  corrective  action  involving  hazardous waste could

often  be considered a generator. One approach to achieving cleanup without

triggering  the  need  to  obtain  a subtitle C permit would be to store or

treat  such  generated  wastes  in tanks within the accumulation period, so

long  as  the  wastes  remained  on  site  for less than 90 days, and other

conditions of Sec. 262.34 were met.



    In  addition,  voluntary  corrective  action  could  take place under a

consent decree issued under section 7003 of RCRA. This authority allows EPA

(or  an  authorized  State  with  comparable authority) to require remedial

action in the case of an imminent and substantial threat to human health or

the  environment,  ''notwithstanding  any  other  provisions of this Act.''

Thus,  under  this authority, EPA could order a facility to take corrective

action,  while  at  the same time waiving permit requirements. Any facility

interested  in taking corrective action under this authority should consult

with  the appropriate Region or authorized State to explore the possibility

of a section 7003 consent order.



    The  concept  of  ''voluntary''  corrective  action  may  also apply to

owner/operators  who  have  been  issued  permits  with  corrective  action

schedules  of  compliance.  Some  facilities,  such  as those with small or

low-risk  contamination  problems,  will  be of relatively low priority for

expending  the substantial resources required to oversee investigations and

studies  and  make  remedy decisions. For those facilities, EPA's oversight

attention  could be deferred for several years while the program focuses on

high  priority  facilities  with  major  environmental  problems.  However,

owner/operators of lower priority facilities may wish, for various reasons,

to  expeditiously  initiate  cleanup  actions,  rather than wait for EPA to

begin  actively  pursuing  corrective action for the facility. EPA strongly

encourages  owner/operator cleanup initiatives at permitted facilities, and

intends  to  facilitate  such  actions  by  minimizing  any  administrative

obstacles which may impede cleanup.

    Owner/operators  may  take  a wide range of remedial-type activities at

RCRA  permitted  facilities without triggering the need for formal approval

by  the  Agency or modification of the permit. Such activities include, for

example, treatment, storage, or disposal of any non-hazardous solid wastes;

excavation  of  hazardous  wastes  for  disposal off site; less-than-90-day

storage  or  treatment  of  hazardous  wastes  in  tanks;  and treatment of

contaminated  ground water in an exempt wastewater treatment unit. However,

some  activities  which may be necessary to achieve corrective action goals

at  the facility would require a permit modification. Such activities might

include creation of a new hazardous waste land disposal unit, consolidation

and/or  movement  of  hazardous  wastes  between  SWMUs at the facility, or

construction  (or movement on site) of a new hazardous waste incinerator to

manage corrective action wastes.



    The  Agency intends to pursue an approach to this type of ''voluntary''

corrective  action  which  will  provide  sufficient  Agency oversight over

cleanup  activities  to prevent possible adverse effects of cleanup actions

without  creating  disincentives  to  owner/operators  who  wish  to take a

proactive position vis-a-vis their corrective action responsibilities. This

approach  would encourage the owner/operator to notify EPA and the State of

any  remedial-type activities being undertaken at the facility, even though

the  activities  are  not  subject  to formal Agency approval. For proposed

cleanup  activities  that  are subject to permit modification requirements,

the  owner/operator would be required to submit a request for a Class I, II

or  III  permit  modification, or a request for temporary authorization for

the  activities.  (See  the  final permit modification regulations at 53 FR

37912,  September  28,  1988.) In the request for a permit modification (or

temporary  authorization), the owner/operator would be expected to include:

(1)  A  description of the remediation initiative, including details of the

unit  or  activity  that  is  subject  to  permit  requirements; and (2) an

explanation   of  how  the  proposed  action  is  consistent  with  overall

corrective  action objectives and requirements outlined in today's proposed

regulation.  EPA  expects  that  the corrective action regulations proposed

today  will  offer  owner/operators clear guidance in fashioning acceptable

remedies and making such showings of consistency.



    EPA's  review  of  the  application would focus on the units or actions

subject  to  the  permit  modification requirements; it would not, however,

focus  on  whether  the  proposed  cleanup  action as a whole satisfies the

subpart  S  requirements.  Rather,  EPA will screen the cleanup proposal to

ensure  that  it  would not pose unacceptable risks to human health and the

environment   (e.g.,  by  producing  undesirable  cross-media  impacts)  or

interfere  with  attainment  of  the  final  remedy  at  the site (e.g., by

creating a new unit over an area of soil contamination which may later need

to  be  treated  or removed to health-based levels). Following this review,

the Agency would approve or disallow the application.



    Where  a permit modification is approved under these circumstances, the

modification  will  make  clear that the voluntary activities initiated for

corrective  action  purposes  may  not  be the final remedy, and that those

activities, when completed, will not necessarily absolve the owner/operator

from further cleanup responsibilities at a {pg 30808} later date. This will

also  hold  for cleanup actions reviewed by the Agency that are not subject

to  permit  modifications. It is not possible for the Agency to delegate to

owner/operators  the  ultimate  responsibility  for  ensuring that remedial

activities  fully  satisfy  RCRA's  statutory requirement for protection of

human health and the environment.



    The  Agency  solicits  comments on the approach to voluntary corrective

action described above.



B. Definitions (Section 264.501)



    EPA   is   today  proposing  to  define  five  key  terms  which  apply

specifically to this subpart.

    1.  Facility.  In the July 15, 1985, Codification Rule, EPA interpreted

the  term  ''facility''  in  the  context  of  section  3004(u) to mean all

contiguous  property  under the control of the owner/operator of a facility

seeking  a  permit  under  subtitle  C. This interpretation was upheld in a

decision  of  the  U.S.  District  Court  of  Appeals  (United Technologies

Corporation  vs. U.S. EPA, 821 F2d. 714 (DC Cir. 1987)). Thus, by proposing

this  interpretation  as the definition of facility in today's rule, EPA is

not  modifying  its  basic  interpretation as previously elaborated for the

purpose  of  implementing  section  3004(u).  There  are,  however, several

aspects of this definition which merit further clarification.



    The  definition  of facility in today's proposal at Sec. 264.501 is not

intended  to  alter  or  subsume  the  existing-and  narrower-definition of

''facility''  that is given in 40 CFR 260.10. That definition describes the

facility  as  ''*  * * all contiguous land and structuresused for treating,

storing  or disposing of hazardous waste * * *'' EPA intends to retain this

definition  for  the purposes of implementing RCRA subtitle C requirements,

with  the  exception  of  subpart  S  corrective  action  (including  those

provisions  governing  corrective  action for regulated units). At the same

time, however, the Agency is reviewing its uses of the term ''facility'' in

other parts of the subtitle C regulations to ensure consistent usage.

    Today's proposed definition refers to ''contiguous property'' under the

control of the owner/operator. Several questions have been raised as to the

Agency's  interpretation  of  ''contiguous  property''  in  the  context of

defining  the areal limits of the facility. Clearly, property that is owned

by  the  owner/operator  that  is located apart from the facility (i.e., is

separated  by  land  owned  by others) is not part of the ''facility.'' EPA

does  intend,  however,  to  consider  property that is separated only by a

public   right-of-way   (such   as   a  roadway  or  a  power  transmission

right-of-way)  to  be contiguous property. The term ''contiguous property''

also  has  significant  additional meaning when applied to a facility where

the  owner  is  a  different  entity  from  the operator. For example, if a

100-acre  parcel  of land were owned by a company that leases five acres of

it  to another company that, in turn, engages in hazardous waste management

on  the  five acres leased, the ''facility'' for the purposes of corrective

action  would  be  the  entire  100-acre  parcel. Likewise, if (in the same

example) the operator also owned 20 acres of land located contiguous to the

100-acre  parcel,  but not contiguous to the five-acre parcel, the facility

would   be   the   combined   120  acres.  EPA  invites  comment  on  these

interpretations of contiguous property.



    In  some  cases,  adjacent  properties  may  be separately owned by two

different  subsidiaries  of  a  parent  company,  where  only  one  of  the

subsidiaries'  operations  involves management of hazardous wastes. In such

cases,  EPA  intends  to  consider  the  ownership to be held by the parent

corporation. Thus, in the example provided, the facility would include both

properties.



    EPA  acknowledges  that,  in some situations, ''ownership'' of property

can  involve  a  complex  legal  determination.  EPA  solicits  comment and

information  on  the interpretation offered in general, and specifically on

the  issue of how ownership or ''control'' of property should be determined

in the context of subsidiary-parent companies.



    2.  Release.  Today's  proposal  includes the definition of ''release''

articulated  in  the preamble to the July 15, 1985, Codification Rule. This

definition  essentially  repeats  the CERCLA definition of release. Today's

proposed  definition  also  includes  language from SARA which extended the

concept   of   ''release''  to  include  abandoned  or  discarded  barrels,

containers,  and  other  closed  receptacles containing hazardous wastes or

hazardous constituents.



    Although  this definition of release is quite broad, section 3004(u) is

limited  to  addressing  releases  from solid waste management units. Thus,

there  may  be  releases  at  a facility that are not associated with solid

waste  management  units,  and that are therefore not subject to corrective

action  under  this  authority.  (See  discussion below which defines solid

waste management unit.)



    Many  facilities  have  releases from solid waste management units that

are  issued  permits  under  other  environmental  laws. For example, stack

emissions  from  a  solid  waste  refuse incinerator at a RCRA facility are

likely  to  be  authorized under a State-issued air permit. Another example

would  be NPDES (National Pollutant Discharge Elimination System, under the

Clean  Water  Act),  or State-equivalent, permits for discharges to surface

water  from  an industrial wastewater treatment system. EPA does not intend

to  utilize the section 3004(u) corrective action authority to supersede or

routinely  reevaluate  such  permitted  releases. However, in the course of

investigating  RCRA facilities for corrective action purposes, EPA may find

situations  where  permitted  releases  from  SWMUs have created threats to

human  health  and  the  environment.  In  such a case, EPA would refer the

information  to  the  relevant  permitting  authority or program office for

action.  If  the permitting authority is unable to compel corrective action

for  the release, EPA will take necessary action under section 3004(u) (for

facilities  with  RCRA  permits)  or  section  3008(h)  (for interim status

facilities),  as  appropriate,  and  to  the  extent  not inconsistent with

certain applicable laws (see section 1006(a) of RCRA).

    3.  Solid  Waste  Management  Unit  (SWMU).  Today's  rule proposes the

following definition of solid waste management unit:



    Any  discernible  unit  at  which  solid wastes have been placed at any

time,  irrespective  of whether the unit was intended for the management of

solid  or  hazardous  waste.  Such  units include any area at a facility at

which solid wastes have been routinely and systematically released.



    This   definition  is  also  derived  from  the  Agency  interpretation

discussed  in  the  July 15, 1985, Codification Rule. A discernible unit in

this context includes the types of units typically identified with the RCRA

regulatory   program,   including  landfills,  surface  impoundments,  land

treatment  units, waste piles, tanks, container storage areas incinerators,

injection  wells,  wastewater  treatment  units, waste recycling units, and

other physical, chemical or biological treatment units.



    The  proposed  definition  also  includes  as  a  type  of  solid waste

management  unit  those areas of a facility at which solid wastes have been

released  in  a  routine  and systematic manner. One example of such a unit

would  be  a  wood  preservative ''kickback drippage'' area, where pressure

treated  wood  is  stored  in  a  manner  which  allows preservative fluids

routinely  to  drip  onto  the  soil, eventually creating an area of highly

contaminated  soils. Another example might be a loading/unloading area at a

{pg  30809}  facility,  where  coupling and decoupling operations, or other

practices  result  in  a  relatively small but steady amount of spillage or

drippage, that, over time, results in highly contaminated soils. Similarly,

if  an  outdoor  area  of a facility were used for solvent washing of large

parts,  with  amounts  of solvent continually dripping onto the soils, that

area could also be considered a solid waste management unit.



    For  clarification  purposes  it may also be useful to identify certain

types  of releases that the Agency does not propose to consider solid waste

management units using the ''routine and systematic'' criterion. A one-time

spill  of  hazardous  wastes  (such as from a vehicle travelling across the

facility)  would  not  be  considered a solid waste management unit. If the

spill were not cleaned up, however, such a spill would be illegal disposal,

and  therefore  subject  to  enforcement  action  under  section 3008(a) or

section  7003  of  RCRA. Similarly, leakage from a chemical product storage

tank  would  generally  not  constitute a solid waste management unit; such

''passive''  leakage  would not constitute a routine and systematic release

since  it  is  not  the  result  of  a systematic human activity. Likewise,

releases  from  production processes, and contamination resulting from such

releases,  will  generally  not be considered solid waste management units,

unless  the Agency finds that the releases have been routine and systematic

in  nature. (Such releases could, however, be addressed as illegal disposal

under  section  3008(a)  or  section  7003.)  EPA solicits comment on these

interpretations,  and  on  the overall definition of solid waste management

unit.



    EPA recognizes that these interpretations have the effect of precluding

section  3004(u)  from  addressing  some  environmental  problems  at  RCRA

facilities.  However,  EPA intends to exercise its authority, as necessary,

under  the  RCRA  ''omnibus''  provision  (section  3005(c)(2)),  or  other

authorities  provided  in  RCRA (e.g., section 3008(a) and section 7003) or

CERCLA  (e.g.,  CERCLA  section 104 or section 106), or States, under State

authorities,  to  correct such problems and to protect human health and the

environment.



    The  RCRA  program  has  identified  certain  specific  units and waste

management  practices  at facilities about which questions have been raised

concerning  applicability  of  the  definition  of a solid waste management

unit. One such question relates to military firing ranges and impact areas.

Such  areas  are  often  potentially  hazardous,  due  to  the  presence of

unexploded  ordnance.  EPA  has  decided  that  such  areas  should  not be

considered  solid  waste  management units. There is a strong argument that

unexploded  ordnance fired during target practice is not discarded material

which  falls  within the regulatory definition of ''solid waste.'' Ordnance

that does not explode, as well as fragments of exploded ordinance, would be

expected  to  land  on  the ground. Hence, the ''ordinary use'' of ordnance

includes  placement on land. Moreover, it is possible that the user has not

abandoned or discarded the ordnance, but rather intends to reuse or recycle

them  at  some  time  in  the  future.  In  addition, a U.S. District Court

decision  (Barcello  vs.  Brown, 478 F. Supp. 646, 668- 669 (D. Puerto Rico

1979)),  has  suggested  that  materials  resulting  from uniquely military

activities  engaged  in  by no other parties fall outside the definition of

solid  waste,  and  thus would not be subject to section 3004(u) corrective

action.



    Another  issue  which  raises  questions  regarding  the  definition of

''solid  waste  management  unit'' relates to industrial process collection

sewers.  Process collection sewers are typically designed and operated as a

system  of  piping  into  which  wastes  are  introduced, and which usually

discharge  into  a  wastewater  treatment  system. The Agency believes that

there  are  sound  reasons  for considering process collection sewers to be

solid waste management units. Such sewers typically handle large volumes of

waste  on a more or less continuous basis, and are an integral component of

many  facilities'  overall  waste management system. Program experience has

further  indicated  that  many  of these systems, especially those at older

facilities, have significant leakage, and can be a principal source of soil

and ground-water contamination at the facility. Although process collection

sewers  are physically somewhat unique in the context of the types of units

which  have  traditionally  been  regulated  under  RCRA, EPA believes that

including  them  as solid waste management units for purposes of corrective

action  is well within the discretion provided under the statute for EPA to

determine what ''units'' should be subject to RCRA standards.



    EPA  recognizes  that  there  may be technical problems associated with

investigating  releases from process collection sewers, and with correcting

leakage.  Information  and  comment  are  specifically  solicited  on EPA's

tentative  decision  to  treat  process  collection  sewers  as solid waste

management   units,   and   on  technical  approaches  and  limitations  to

investigating and correcting releases from such systems.



    For essentially the same reasons as described above for process sewers,

EPA  also  proposes  to  include  open (or closed) ditches that are used to

convey  solid  wastes  as  solid  waste  management  units; comment is also

solicited on this interpretation.



    4. Hazardous Waste and Hazardous Constituents. Section 3004(u) requires

corrective action for releases of ''hazardous wastes or constituents.'' The

Agency   believes   that  use  of  the  term  ''hazardous  waste''  denotes

''hazardous  waste''  as  defined  in section 1004(5) of RCRA. Accordingly,

today's  proposed  rule  repeats  the  statutory  definition of ''hazardous

waste''   found   in   that   section.  The  term  ''hazardous  waste''  is

distinguished  from  the  phrase ''hazardous waste listed and identified,''

which  is  used elsewhere in the statute to denote that subset of hazardous

wastes specifically listed and identified by the Agency pursuant to section

3001  of  RCRA.  Thus,  the remedial authority under section 3004(u) is not

limited  to  releases  of  wastes specifically listed in 40 CFR part 261 or

identified  pursuant  to  the  characteristic  tests found in that section.

Rather,  it  extends  potentially  to  any  substance meeting the statutory

definition. However, EPA believes that use of the phrase ''hazardous wastes

or constituents'' (emphasis added) indicates that Congress was particularly

concerned  that  the  Agency use the section 3004(u) authority to address a

specific subset of this broad category, that is, hazardous constituents.



    The  term ''hazardous constituent'' used in section 3004(u) means those

constituents  found  in  appendix  VIII to 40 CFR part 261. See H. Rep. No.

98-198,  98th Cong., 1st Sess. 60-61, May 17, 1983. In addition, the Agency

proposes  to include within the definition those constituents identified in

appendix  IX to 40 CFR part 264. Appendix IX generally constitutes a subset

of  appendix  VIII  constituents  particularly  suitable  for  ground-water

analyses.  However,  it  also includes additional constituents not found on

appendix VIII, but commonly addressed in ground-water analysis conducted as

a part of Superfund cleanups.



    It  is  EPA's intention that investigations of releases under subpart S

focus  on  the subset of hazardous waste (including hazardous constituents)

that  is  likely  to  have been released at a particular site, based on the

available   information.   Only   where  very  little  is  known  of  waste

characteristics,  and  where  there  is  a  {pg 30810} potential for a wide

spectrum  of  wastes  to  have  been  released, would the owner/operator be

required to perform extensive or routine analysis for a broader spectrum of

wastes.



    5.  Corrective Action Management Unit (CAMU). The definition of CAMU is

provided  in  section  VI.J  3.b  of  today's  preamble.  This section also

provides  a  thorough  discussion of the CAMU concept and of how the Agency

intends to define CAMUs in the context of implementing remedies.



C. Remedial Investigations (Sections 264.510-264.513)



    1.  General.  The RCRA Facility Investigation (RFI) is the second phase

of  the RCRA corrective action process, and will typically be preceded by a

RCRA  Facility  Assessment  (RFA),  conducted  by EPA or the State prior to

issuance  of the permit or section 3008(h) order. The RFA is the first step

in  the RCRA corrective action process, and is analogous to the Preliminary

Assessment/Site  Investigation  (PA/SI) stage of the Superfund program. The

RFA  serves  as a screen, eliminating solid waste management units (SWMUs),

environmental  media, or entire facilities from further consideration where

the  Agency determines that there is no evidence of a release or likelihood

of  a  release that poses a threat to human health and the environment. The

RFA also serves to focus the scope of the follow-on remedial investigations

by  identifying  those releases or areas that are of the most environmental

concern  at  the  facility.  The  RCRA  RFI  is  comparable to the Remedial

Investigation  in  the  Superfund program. Because of the similarity of the

two  processes and because of their common goals, the RFI is referred to in

this   section  and  in  the  rule  by  the  more  generic  term,  remedial

investigation.



    As  described  above,  EPA would require a remedial investigation under

proposed  Sec.  264.510 if the RFA indicated that a release from a SWMU was

likely  to  have  occurred  or  to  be  occurring,  or,  in certain limited

circumstances, likely to occur in the future. Requirements for the remedial

investigation  would be specified by the Agency in a schedule of compliance

in  the  facility's permit. The schedule would typically identify the SWMUs

and  environmental  media that required more detailed investigation as well

as  the  types  of investigations required; it would also typically require

the  owner/operator  to develop a plan for conducting these investigations.

The  permit  would also include ''action levels'' for specific constituents

in   specific   media  under  investigation.  If  subsequent  investigation

indicated  that these action levels had been exceeded, a Corrective Measure

Study could be required by the Agency.



    EPA  has  recently  issued  a  guidance document entitled RCRA Facility

Investigation  Guidance, which describes a menu of technical investigations

that  may be appropriate to conducting remedial-type investigations at RCRA

facilities.  EPA  wishes to emphasize that the nature and scope of remedial

investigations  for  RCRA  facilities  under  proposed Sec. 264.510 will be

tailored  to  the  specific  conditions  and circumstances at the facility.

Investigations  will  be  focused  on  the  specific  units,  releases, and

exposure  pathways  that  have  been identified by EPA to be of concern. In

some  cases,  the  scope  of  a  remedial investigation could be limited to

taking  several  soil  samples  of  a  particular area of discolored soils.

Likewise,  for  inactive  units  that do not contain substantial volumes of

volatile  organic  compounds,  remedial  investigations will rarely need to

address  air  releases.  In  defining  the  nature  and  scope  of remedial

investigations   at   RCRA   facilities,  EPA  will  endeavor  to  minimize

unnecessary  and  unproductive  investigations,  and  to focus resources on

characterizing actual environmental problems at facilities.



    Today's  rule,  in Secs. 264.511 through 264.513, proposes a regulatory

framework   (both  procedural  and  substantive)  for  conducting  remedial

investigations.  For  more  information  on  technical  approaches to these

investigations,  readers  should  refer to the RFI Guidance, which has been

included in the public record of this rulemaking.



    EPA  also  anticipates  that  remedial investigations will typically be

phased,  to avoid unnecessary investigations where a concern can be quickly

eliminated. Because of the importance of accurate data, and the likely need

to  extend  or  modify  the  analysis  as  data are developed, the remedial

investigation  will often, in addition, require a high level of interaction

between  the  permittee  and the Agency. The specific contents and scope of

the investigations are described below.



    2.  Scope  of  Remedial  Investigations  (Sec.  264.511). Proposed Sec.

264.511 defines in general terms the scope of remedial investigations which

may  be  required  under  Sec. 264.510. Proposed Sec. 264.511(a) states the

general performance objective that remedial investigations characterize the

nature,  extent,  direction, rate, movement, and concentration of releases,

as   required   by  the  Agency.  The  scope  and  complexity  of  remedial

investigations  will  depend on the nature and extent of the contamination,

whether the releases have migrated beyond the facility boundary, the amount

of existing information on the site, the likely risk at the site, and other

pertinent   factors.   The  proposed  general  performance  standard  gives

considerable  flexibility  to  the  Agency  in defining the specific scope,

level of detail, and data requirements for each remedial investigation. The

specific  investigation  requirements  deemed  to be appropriate at a given

facility  will  be  included  in  the  permit  as  part  of the schedule of

compliance.



    Proposed  Secs. 264.511(a)(1)-(7) provide a menu of more specific types

of  information  that  may  be  required  in  remedial  investigations: (1)

Characterization  of  the  environmental  setting;  (2) characterization of

solid   waste   management   units;  (3)  description  of  the  humans  and

environmental  systems  which are, have been, or may potentially be exposed

to  the  release;  (4) information that will assist the Agency in assessing

the  risk  posed  to  humans  and environmental systems by the release; (5)

extrapolations of future contaminant movement; (6) laboratory, bench-scale,

or   pilot-  scale  tests  or  studies  to  determine  the  feasibility  or

effectiveness  of  treatment or other technologies which may be appropriate

in  implementing  remedies at the facility; and (7) statistical analyses to

aid in the interpretation of data required in the investigation.



    The   RFI   Guidance   describes  in  detail  technical  approaches  to

characterizing   the   releases  and  environmental  settings  in  remedial

investigations.  In  addition,  the  RCRA Ground-Water Monitoring Technical

Enforcement Guidance Document (September 1986) provides specific guidelines

for characterizing ground-water releases. Therefore, this preamble will not

describe in detail these technical procedures.



    Section  264.511(a)(1)(i)-(v)  describes five types of information that

may  be  required  in  a  characterization  of  the  environmental setting:

Hydrogeologic  conditions; climatological conditions; soil characteristics;

surface  water  characteristics including sediment quality; and air quality

and  meteorological  conditions.  This  information  would  be  required as

appropriate  to  address  the  concerns  identified  in  the  RFA. Specific

requirements  for  the  facility will be included in the permit schedule of

compliance.



    Section  264.511(a)(2) would allow EPA to require a characterization of

any  SWMU  from  which  releases  may  be  {pg 30811} occurring or may have

occurred.  This characterization, which could include chemical and physical

analyses,  will  often  be  important  in  making decisions as to potential

source  control  measures  that  may  be needed. Characterization of wastes

contained  in  SWMUs  may  involve generation of chemical and physical data

about the wastes, their constituent breakdown, volumes, concentrations, and

other  relevant data. In some cases, unit characteristics such as materials

of  construction,  age,  or type and thickness of liners may be relevant to

remedy decisions.



    Section  264.511(a)(3)  proposes  that the Agency may require a full ''

description  of human and environmental systems which are or may be exposed

to  release(s).'' The proximity and distribution of exposed populations may

indicate  the  need  for interim measures as proposed under Sec. 264.540 of

today's  rule.  Useful  exposure information will generally be available at

facilities  with landfills or surface impoundments, in the form of Exposure

Information Reports required under section 3019 of RCRA. The RFA report may

also  provide  useful  information on human and environmental systems which

may  potentially  be  exposed.  Where information available prior to permit

issuance  does not adequately identify potentially exposed populations, EPA

will  require  this information, as appropriate, to be generated as part of

the remedial investigation.



    The  Agency  is also concerned with the potential exposure of sensitive

environmental  species  or  systems  to  releases  from  SWMUs.  As  in the

Superfund  program,  the  Agency  intends  to carefully evaluate effects on

sensitive   environmental   systems,  including  wetlands,  estuaries,  and

habitats of endangered or threatened species.



    Section  264.511(a)(4)  would  provide the Agency with the authority to

require  information  that  will  assist  the Regional Administrator in the

assessment  of risks to human health and the environment from releases from

solid   waste   management   units.   Information   collected   under  Sec.

264.511(a)(3)  also  would  be  used  in  the  assessment of risk. The risk

assessment  would  integrate information on exposed human and environmental

systems  and  information  on  contaminant  concentrations  to  assess  the

magnitude  of threats to exposed populations. The Agency may perform a risk

assessment  to  determine whether interim measures are appropriate prior to

selecting  the  final  remedy  or  to  evaluate  whether a determination is

warranted  so  that  no  further  action  is necessary (under proposed Sec.

264.514).  The  permittee  should refer to chapter VIII of the RFI Guidance

for  information  regarding  the Agency's expectations for data that may be

needed to conduct a risk assessment.



    Section  264.511(a)(5)  would  provide  the authority for the Agency to

require   a  permittee  to  submit  information  that  extrapolates  future

contaminant  movement.  Such  information could be important in determining

whether  interim  measures will be required to prevent further migration of

contamination  and what measures are likely to be effective in doing so. In

addition,  extrapolated contaminant movement will be important in assessing

the adequacy of proposed schedules of implementation of the remedy.



    Section  264.511(a)(6)  would  provide the Agency with the authority to

require  ''  laboratory,  bench-scale,  or  pilot-scale tests or studies to

determine  the  feasibility or effectiveness of treatment technologies that

may  be appropriate in implementing remedies at the facility.'' It is often

difficult,  and  sometimes  impossible,  to  predict  the  effectiveness of

treatment  technologies  accurately without data from bench- or pilot-scale

studies. Experience in the Superfund program has shown that bench-scale and

pilot-scale studies can be useful both in developing potential remedies and

in  predicting the effectiveness of alternative approaches. Typically, such

studies would be performed during the Corrective Measure Study (CMS) (which

may  be  required  after a contaminant concentration level specified in the

permit  as  an  ''action  level'' is exceeded). However, in some cases such

studies  may  need  to  be  initiated  during the remedial investigation to

prevent  delays  in  cleanups,  and  the  Agency should have the regulatory

authority  to  require  this.  For  example,  at  SWMUs at facilities where

confirmed  releases  have  occurred  over  a  long period of time and where

wastes  placed in those SWMUs were highly toxic or mobile, it should not be

necessary  to  wait  for  the CMS phase of the corrective action process to

begin to evaluate, on a small scale, the effectiveness of various treatment

technologies   in   achieving   protective   concentration  levels  in  the

contaminated medium.



    Section  264.511(a)(7)  would  provide  the authority for the Agency to

require  a  permittee  to  perform  statistical  analyses  to  aid  in  the

interpretation  of  data collected through remedial investigations required

under Sec. 264.510. For example, such statistical analyses may be needed to

determine  whether  measured  concentrations  of contaminants exceed action

levels.



    Section  264.511(b)  would  authorize  the  Regional  Administrator  to

specify  the constituents and parameters for which samples collected during

remedial  investigations  would  be  analyzed. Generally, analyses required

will  be  limited  to  certain  hazardous  wastes or hazardous constituents

listed  in  appendix  VIII of 40 CFR part 261 or appendix IX of 40 CFR part

264  that  are  known  or  suspected  to  have been released from the unit.

However,  in  some cases, where the wastes disposed in the unit are unknown

to  the  owner/operator,  or  the  unit  is  known  to  contain a hazardous

substance(s)  not included on either appendix VIII or IX, referenced above,

additional analyses may be required. In the first case, it may be necessary

to have an initial analysis which is designed to scan, for example, for all

appendix   IX  constituents.  Further  analyses  may  then  be  limited  to

constituents  which  are  found  to  be  present  in the initial sample. In

addition,  EPA may stipulate a requirement to analyze for substances not on

either  appendix  VIII  or IX (see preamble discussion on the definition of

''hazardous  waste'').  Authority  to specify the analyses to be performed,

and for which constituents, will be important in ensuring that quality data

are  developed  to  accurately  characterize  releases,  and  to support no

further action decisions that may be appropriate.



    3.  Plans  for  Remedial  Investigations  (Sec. 264.512). Under today's

proposed  Sec.  264.512,  permittees  may  be required to submit a plan for

conducting  the remedial investigation if an investigation is determined to

be necessary. The Agency considered, but is not proposing, making submittal

of  such  plans  an  absolute  requirement;  that  is,  expressing  it as a

''shall'' rather than a ''may''. In some cases the Region or State may have

extensive  knowledge  of  the facility prior to permit issuance, and may be

able  to specify, in detail, how the investigations should be conducted. In

this  situation, it would not be necessary to require the owner/operator to

submit a workplan for approval. Likewise, in some other cases the permittee

may  have  begun remedial investigations under an interim status corrective

action  order,  under  CERCLA,  or on a voluntary basis. Where the workplan

developed  for investigations prior to permit issuance is determined by the

Regional  Administrator to be adequate, it will not be necessary to require

submission  and  approval of the current plan-that plan would simply be {pg

30812}  incorporated  into  the  permit.  In  the  great majority of cases,

however,  the  Agency  believes that plans for remedial investigations will

need  to be submitted by the permittee. The permit would specify a schedule

for  submission of the plan, as well as the elements the plan must include.

These  requirements  will generally reflect the complexity of the situation

to  be  addressed.  The Agency considered a requirement that would impose a

definite  deadline  for every owner/operator required to submit an RFI plan

(e.g.,  90  days  after  permit  issuance).  Typically  90  days  would  be

sufficient  time for an owner/operator to develop and submit a plan for the

investigation.  However, the circumstances at some facilities may be highly

complex  (e.g.,  location  above  a Karst formation) and may mean that more

than  90 days would be required to develop an adequate plan. Further, where

the  Agency  must  set  priorities  to manage a heavy work load, facilities

suspected  of  having serious contamination may be required to submit plans

more quickly. Therefore, EPA has not proposed a specific time period within

which  the  plan must be submitted, but the Agency is soliciting comment on

whether  such  an  approach  is preferable to the more flexible approach in

today's proposal.

    Plans for conducting remedial investigations would be subject to review

and approval or modification by the Regional Administrator. When a workplan

submitted  for  the  Regional  Administrator's approval does not adequately

address  all  elements of the investigation, the Regional Administrator may

either  disapprove the plan and return it to the permittee for revision, or

make  modifications  to  the  plan  and  return  the  modified  plan to the

owner/operator  as  the  approved plan. The latter approach is analogous to

the  discretion provided the Regional Administrator to modify closure plans

submitted  by  an  owner/operator  pursuant  to Sec. 265.112 during interim

status, or through a Notice of Deficiency during the permitting process. An

approved plan will establish both requirements applicable to the conduct of

the investigation and a schedule for its implementation. Section 264.512(b)

would  provide  regulatory  authority  for  enforcing  compliance  with the

approved  plan, which becomes an enforceable part of the permit schedule of

compliance.  In  most  cases,  it  is expected that the initial permit will

specify  that  the plan becomes an enforceable component of the permit upon

approval.  Alternatively,  the  permit  may  be modified to incorporate the

provisions of the approved plan.



    Proposed  Sec.  264.512(a)  lists items that the Regional Administrator

may require in the work plan. Such plans should generally call for focused,

staged  investigations,  the scope and emphasis of which will be refined as

releases  are  verified  and/or  found not to have occurred. The work plans

would  generally  include: A description of overall approach; technical and

analytical  approaches  and methods; quality assurance procedures; and data

management  procedures  and  formats  to  document and track the results of

investigations.  In  addition,  the Regional Administrator may impose other

elements,  as  necessary,  to  assure  that  work  undertaken will be of an

adequate  quality  (and  an  appropriate  level  of detail) to serve as the

primary  basis  for  decisions  on  further stages of the corrective action

process that may be necessary at the facility.



    The  description of the overall approach, which could be required under

proposed  Sec.  264.512(a)(1), would generally include a description of the

objectives  of  the  investigation, its schedule, and the qualifications of

the  persons  conducting  the  investigation.  The schedule is particularly

important because, when approved, it will become enforceable as part of the

schedule of compliance.



    A  requirement to specify the technical and analytical approaches to be

employed  (under  proposed Sec. 264.512(a)(2)) might include specifications

for  the  location, construction, and frequency of sampling of ground-water

monitoring  wells.  This  would be analogous to the types of specifications

for wells that are typically in permits for land disposal units.

    Submissions   of  proposed  quality  assurance  procedures  under  Sec.

264.512(a)(3)  would  be evaluated to ensure that data generated during the

investigation  are  accurate,  and that they can be used with confidence to

support  the  next  steps  of  the  corrective  action process. Guidance on

appropriate  quality assurance procedures may be found in the RCRA Facility

Investigation Guidance.



    Data  management  procedures and formats for documenting results of the

investigation  are  included  in proposed Sec. 264.512(a)(4) to ensure that

RFI  data  and summary results are presented in a clear and logical manner.

Studies  such  as  the RFI typically produce large amounts of data, such as

laboratory  analyses  of numerous waste constituents from numerous samples.

Effective data management and presentation will be necessary to ensure that

the data can be properly interpreted.



    4.  Reports  of  Remedial  Investigations (Sec. 264.513). Proposed Sec.

264.513  would  establish the Regional Administrator's authority to require

periodic  reports that summarize results of remedial investigations. Timing

of the reports, as well as specific content requirements, would be detailed

in the permit schedule of compliance. The report format may be specified by

the  Regional  Administrator where necessary to ensure presentation of data

in an orderly and easily comprehensible fashion.

    The  Agency  considered,  but  is  not  requiring  in today's proposal,

specifying intervals for reports (e.g., such as every 180 days). The Agency

believes  that  there  should be flexibility in the timing of submission of

reports  to  reflect the nature of the investigations which may be required

at  specific  facilities.  For  example,  where  extensive  monitoring-well

construction and sampling are necessary, months may pass before significant

results  are  gathered. On the other hand, where limited soil sampling of a

few  SWMUs  is  required  to  confirm  or disprove suspected contamination,

meaningful results may be achieved more quickly.



    Where  data  generated  during  the  investigation  (or which are newly

available  from  other  sources)  indicate that the investigation should be

modified,  the Regional Administrator may require such modifications either

by  negotiation with the facility owner/operator, or through a modification

to  the  schedule of compliance. Modifications could occur, for example, if

the  investigation  revealed that contamination had migrated, or would soon

migrate,  off site. In such a case, additional activities may be imposed as

interim  measures  to  contain  the contamination until active, longer term

remediation could begin. Further, new information may indicate the need for

additional investigations, or the Regional Administrator may need to modify

the investigation requirements based on preliminary analytical results.

    Proposed Secs. 264.513(b) and 264.513(c) would require the permittee to

submit  a  final  report of the investigation to the Regional Administrator

for approval, and would allow the Agency to require the permittee to add to

or otherwise revise the report if it did not fully and accurately summarize

the  results  of  the  remedial  investigation.  This  authority to require

revisions  should  ensure  that  adequate  information (both in quality and

level  of  detail)  is  presented  to {pg 30813} support further corrective

action decisions for the facility.



    In  addition  to  the  final report, the permittee would be required to

submit  a  summary  of  the  report under proposed Sec. 264.513(b)(2). This

summary   would   also   be   subject  to  the  approval  of  the  Regional

Administrator,  and  would  be  mailed to all individuals on the facility's

mailing  list  by  the owner/operator. (The facility mailing list, which is

required  under  40  CFR 124.10(c)(1)(viii), is developed and maintained by

EPA  as  part  of  the permitting process.) This proposed requirement is an

important  element  of the Agency's overall public involvement strategy for

corrective action, which is described in further detail in today's preamble

under section VIII. Distribution of the summary in this manner will provide

notice  to interested parties as to the general nature of the environmental

problems  at the facility, what releases have been found, and other results

of investigations.

    Section  264.513(e)  would  require that the permittee maintain all raw

data  (such  as  laboratory  reports,  drilling  logs, and other supporting

information)  at  the  facility  for  the duration of the corrective action

activities and any permit period unless the Regional Administrator approves

maintaining  this  information  in a different location. Although such data

will  often  be  required to be submitted along with investigation reports,

this  requirement  will  ensure  that  when  questions  do arise concerning

interpretation  of  data  or  the adequacy of procedures used to obtain and

analyze data, the original records will be available for inspection.



D. Determination of No Further Action (Section 264.514)



    EPA  anticipates that at some facilities releases or suspected releases

that  are  identified in a RCRA Facility Assessment (RFA), and subsequently

addressed  as part of required remedial investigations, will be found to be

non- existent, or otherwise of such a nature that they do not pose a threat

to  human  health or the environment. EPA proposes providing a mechanism by

which  a  permittee  may  request  a  permit  modification  to  effectively

terminate further requirements in these cases.



    Section  264.514  proposes  the  procedures  to be followed by both the

permittee and the Regional Administrator when a determination of no further

action   for   the  facility  is  requested.  The  request  for  an  Agency

determination  that  no  further  action is required, and the corresponding

permit   modification   request,   must   be   accompanied   by  supporting

documentation  that  demonstrates  that  there are no releases of hazardous

waste  (including  hazardous constituents) from SWMUs at the facility which

pose  a  threat  to  human  health  or  the environment. (See proposed Sec.

264.514(a)(2).)



    Under proposed Sec. 264.514(a) the permittee may request a modification

of  the  facility  permit  to  terminate  the  schedule  of  compliance for

corrective  action  based  on  the findings of remedial investigations. The

request  would  be  initiated  according  to  the procedures of a Class III

permit  modification.  (See  the  September  1988 final permit modification

rule.)  These  procedures would require the permittee to notify all persons

on the facility mailing list of the proposed change and publish a newspaper

notice concerning the request; both notices must announce the initiation of

a  60  day  comment  period  as  well as the time, date, and location of an

informational   public  meeting.  In  addition,  a  copy  of  the  proposed

modification  and  supporting  documentation  must  be placed in a location

accessible to the public in the vicinity of the permitted facility. (In the

case  of  proposed  modifications  at  facilities  required to establish an

information repository under Sec. 270.36 of today's proposal, this location

would  be the information repository.) More detailed information concerning

the  requirements  for  a Class III permit modification may be found in the

rule for permit modifications cited above and the preamble discussion which

accompanies it.



    Under  proposed  Sec.  264.514(b), if the Regional Administrator, using

all  available  information (including comments received during the comment

period  required  for Class III modifications), determines that releases or

suspected releases investigated either do not exist or do not pose a threat

to  human  health or the environment, the Regional Administrator will grant

the requested permit modification.



    This  determination  will  be  straightforward  where the permittee can

demonstrate that no release has occurred; however, such a determination may

still  be  supported when a release has occurred, whether the release(s) is

either  below or above action levels. For example, such a determination may

be  made when concentrations of hazardous constituents exceed action levels

but  the  contamination is in a highly saline (Class III) aquifer, or where

contamination in ground water can be shown to have originated from a source

outside  the  facility.  Such  a determination would be consistent with the

provision  made in today's proposal at Sec. 264.525(d)(2)(ii), which allows

certain  cleanup  exemptions  when contamination is present in ground water

that  is  neither  a  current  or  potential  source  of drinking water nor

potentially  usable  for  other  human purposes. Another example where a no

further  action  determination  might be made is where it can be determined

that contaminant levels (and the risks posed by them) from a release from a

SWMU are insignificant as compared to existing ''background'' levels (e.g.,

levels  that  are  naturally occurring, or that have resulted from releases

from outside the facility). This determination would be consistent with the

provision made in today's proposal at Sec. 264.525(d)(2)(i).



    A  determination that no further action is required under Sec. 264.514,

and  the  subsequent  termination  of the permit schedule of compliance for

corrective action, does not affect other responsibilities or authorities of

the  Regional  Administrator.  For  example,  responsibilities  to  include

requirements  in  a  permit  for air emissions control and monitoring under

section  3004(n) are not affected by a determination that no further action

is   required   under   Sec.  264.514  (see  preamble  section  VII.C.3  on

relationship  to  section 3004(n) standards). In addition, the authority of

the  Regional  Administrator  to  modify  the permit under Sec. 270.41 at a

later  date to require corrective action investigations or studies based on

new information is not affected. Furthermore, despite a determination under

Sec.  264.514,  EPA  may  require  continuing  or  periodic monitoring when

site-specific  circumstances  indicate that releases are likely to occur in

the future. For example, for a particular SWMU from which releases have not

occurred,  it  may  be  reasonable  to  conclude,  based  on  site-specific

circumstances,  that  releases to ground water might be expected within the

next  several  years  (i.e.,  the term of the permit). In these situations,

continued monitoring requirements could be imposed.



    Where  the  permit  schedule  of compliance has been terminated and the

Regional  Administrator subsequently determines that a new investigation or

remediation  is  required, the Regional Administrator will initiate a major

permit  modification  under  Sec.  270.41  to require further action by the

permittee.



E. Corrective Measure Study (Sections 264.520- 264.524)



    1.  Purpose  of  Corrective Measure Study (Sec. 264.520). Proposed Sec.

264.520  would  establish  the  authority  of the Regional Administrator to

require  the  permittee  to  perform  a Corrective Measure Study (CMS). The

remedial  {pg  30814}  investigation should serve to focus the CMS on units

which  are  sources  of  releases  and  the media pathways affected by such

releases.  The  CMS is designed to identify and evaluate potential remedial

alternatives for the releases that have been identified at the facility; in

this  respect  it  is analogous to the Feasibility Study (FS) conducted for

CERCLA remedial actions.



    2. Trigger for Corrective Measure Study (Sec. 264.521)-a. Use of Action

Levels.  Action levels are defined in proposed Sec. 264.521. Under proposed

Sec.  264.520(a),  the  Regional Administrator may require the permittee to

conduct  a  Corrective  Measure  Study whenever concentrations of hazardous

constituents  in  an  aquifer,  surface  water, soils, or air exceed action

levels for any environmental medium.



    Action  levels are health- and environmental-based levels determined by

the  Agency  to  be  indicators  for  protection  of  human  health and the

environment.  The  Agency  proposes  to  set  action  levels  for hazardous

constituents,  a subset of hazardous wastes. Many hazardous wastes, such as

some  of  the wastes listed in 40 CFR 261.32, are not specific constituents

at all, but rather are complex mixtures comprised of many constituents. EPA

believes  that  it would not be feasible in most cases to set action levels

for   such  wastes.  Conversely,  other  hazardous  wastes  are  individual

constituents  that  do  not  appear  on appendix VIII to 40 CFR part 261 or

appendix  IX  to  40 CFR part 264. When such wastes (e.g., asbestos) are of

concern at a facility, an action level would be specified for that waste.



    Where  appropriate,  action  levels  are based on promulgated standards

(e.g., maximum contaminant levels established under the Safe Drinking Water

Act).  In  other  cases,  action  levels  are  established  by the Regional

Administrator  on the basis of general criteria (see following discussion).

Appendix  A provides examples of concentrations derived by EPA according to

these criteria for some appendix VIII and IX constituents.



    The  Agency  is  proposing  the  use  of  action  levels because active

remediation  may  not  be necessary at all facilities required to perform a

remedial  investigation  under  proposed  Sec.  264.510.  For  instance,  a

remedial  investigation may indicate that a suspected release identified in

the  RFA  had,  in  fact,  not  occurred,  or  may  indicate that levels of

contamination from a past release are unlikely to present a threat to human

health  and  the  environment.  Therefore,  the  Agency  believes it should

establish  a trigger that will indicate the need for a CMS, and below which

a CMS would not ordinarily be required.



    Action  levels  will, whenever possible, be incorporated in the permit.

The  Agency  believes  it  is advantageous to identify action levels in the

permit  so  that  the  public  and  the permittee will know in advance what

levels  will  trigger  the requirement to conduct a CMS. This approach also

minimizes  the  need  for  permit modifications later in the process, which

could delay ultimate cleanup.

    In  some  cases  there  may be sufficient information on the nature and

levels  of  contamination  at  the time of permit issuance to establish the

need  for  a  Corrective  Measure  Study.  In  such  cases, it might not be

necessary to include action levels in the permit. However, it is more often

likely  that  remedial  investigations conducted after permit issuance will

yield the data needed to determine if action levels are exceeded; hence the

need to generally include the action levels in the original permit.



    A  determination that action levels have been exceeded may occur at any

point during the RFI, or may not become evident until the RFI is completed.

In  either  case,  when  such data become available, the permit schedule of

compliance  will  provide for notification of the permittee that the action

levels  specified  in the schedule have been exceeded. The notification, as

provided   in  proposed  Sec.  264.520(d)  would  specify  which  hazardous

constituents  exceed action levels, for which media, and when initiation of

a CMS is required.



    It is the Agency's intention that the action level ''trigger'' approach

as  outlined  in  this proposal serves to identify early in the process the

need  for  initiating  a  Corrective  Measure  Study;  such  studies should

typically not be delayed pending completion of all remedial investigations.

In  many instances it will be appropriate to conduct simultaneously the RFI

and CMS for the facility.



    Action levels should be distinguished from cleanup standards, which are

determined  later in the corrective action process. Contamination exceeding

action  levels  indicates  a  potential  threat  to  human  health  or  the

environment  which may require further study. Action levels also inform the

permittee  of  the  levels  below  which  the Agency is unlikely to require

active  remediation  of  releases,  and  provide  a  point of reference for

suggesting and supporting alternative remedial levels.



    Section   264.520   allows,   but   does   not  require,  the  Regional

Administrator to require a CMS when contamination exceeds action levels. In

some  cases, the permittee may rebut the presumption that a CMS is required

when  action  levels are exceeded. For example, the permittee may establish

that  the  contamination is not due to releases from solid waste management

units  at  the  facility. In other instances, the permittee may demonstrate

that  a  CMS  is  not  required  (or only a limited CMS is required) if the

release  is  confined  to  a Class III aquifer meeting the criteria of Sec.

264.525(d)(2)(ii)  or  to  ground  water other than Class III for which the

actual  and  reasonably  expected  uses  do  not  merit  further action. In

addition,  a  CMS  might  not  be  required  if  the  CMS is triggered by a

carcinogenic  hazardous  constituent that slightly exceeds the action level

but  is  within  the 1X10sup -4 to 1X10sup -6 risk range that is protective

for  the site (see preamble section VI.F.5.b for discussion of risk range).

This ''rebuttal'' of the need for a CMS would generally be made through the

process for determination of no further action, proposed in Sec. 264.514.



    Conversely,  the  fact  that no contaminants are found to exceed action

levels  does  not preclude the Regional Administrator from requiring a CMS.

Section  264.520(b) would allow the Regional Administrator to require a CMS

if  concentrations below action levels may pose a threat to human health or

the environment, due to site- specific exposure conditions. (See discussion

in section VI.E.2.h of today's preamble, below.)



    In  some  situations  it  may  not  be  obvious from the available data

whether  concentrations in media truly exceed action levels. This situation

would  arise  when some data on a hazardous constituent indicate that it is

present  at  a  concentration  less than the action level, while other data

indicate  that  it  is  present  at a concentration greater than the action

level.  In  such  situations,  the  Regional  Administrator may require the

permittee   under   Sec.   264.511(a)(7)  to  provide  additional  data  or

statistical  analyses  to  aid  in  the determination under Sec. 264.520 of

whether  action  levels are exceeded. For example, a tolerance, prediction,

or confidence interval procedure may be required, in which the action level

is  compared  to  the  upper limit established from the distribution of the

data for the concentration of the constituent.



    The  Agency  considered  the  alternative  of  establishing a mandatory

requirement  to perform a statistical analysis as part of the determination

under  Sec.  264.520  that  action  levels have been exceeded. However, the

Agency  believes that it is unnecessary to make this requirement mandatory,

since in {pg 30815} many cases contamination from SWMUs will greatly exceed

action  levels.  The  Agency  believes  that  the  diversity  of  SWMUs and

contamination  scenarios  calls  for  some discretion in the requirement to

perform   statistical   analyses.   For   example,   in   some  situations,

contamination  from  a  SWMU  may  be  known  to  be  extensive in size and

concentration.  In  such situations, statistical analyses are not needed to

determine  that  an  action level has been exceeded. In other situations, a

contaminant  release  at a SWMU may not be extensive enough (either in size

or  concentration)  to  clearly  indicate  contamination. In these cases, a

statistical  test  may  be  required to determine if a release has actually

occurred  in  excess  of  action levels. The Agency requests comment on its

proposed  approach of providing discretion to the Regional Administrator in

requiring  statistical  analyses,  and  on  the  alternative of making such

analyses mandatory in determining whether action levels have been exceeded.

    The  Agency  examined but did not propose two alternatives to requiring

the  Corrective  Measure  Study  which  did  not  involve the use of action

levels. Under one approach, the Agency would have required the permittee to

conduct   a   Corrective  Measure  Study  concurrently  with  the  remedial

investigations  conducted  pursuant to Sec. 264.510. Under this option, the

Agency  would  have used the same trigger for requiring a CMS as is used to

require  an RFI-the finding of an existing or likely release pursuant to an

RFA.  This  alternative was rejected because of its potential for requiring

unnecessary studies.



    The second alternative considered by the Agency would have required the

permittee  to  conduct  a Corrective Measure Study only after completion of

the  remedial investigation conducted pursuant to proposed Sec. 264.510 and

a determination of the need to protect human health and the environment. If

the  Agency  had  adopted  this  approach,  it  would not have required the

permittee  to conduct a CMS until all contamination and contaminant sources

at  the  facility  were  fully  characterized  and  the need for corrective

measures   at  the  facility  was  established.  The  Agency  rejected  the

alternative  because  of the delay that would be associated with conducting

these  phases  of the investigations sequentially even in cases where early

data indicate that remediation is highly likely to be required.

    The  Agency  also  examined  alternative  approaches for setting action

levels.  One  alternative  would  have  required a Corrective Measure Study

whenever background levels of contaminants were exceeded. Experience in the

subpart  F  program  has  demonstrated that the determination of background

levels  can  be  a  lengthy, controversial process. Furthermore, background

levels  will  often  be  much  lower  than  health-based levels. Thus, this

alternative  was  rejected,  since it might delay the initiation of the CMS

and  ultimate  cleanup,  and might often require Corrective Measure Studies

even  where  levels were significantly below health and environmental-based

standards.



    A  second  alternative  would  have  required  a CMS whenever detection

limits  were  exceeded. This alternative was also rejected, since detection

limits can be difficult to define and do not directly relate to the goal of

corrective action; that is, protection of human health and the environment.



    The  Agency  also  considered  but  did  not  adopt  an alternative for

requiring  the  Corrective  Measure  Study  that would involve the use of a

range  of  action  levels.  Under  this  approach,  the Agency would select

constituent-specific action levels within the 1X10sup -4 to 1X10sup -6 risk

range  based on the exposure scenarios proposed under Secs. 264.521 (a)(2),

(b),  (c)(3),  and  (d), depending on the likelihood that exposure would in

fact  occur.  For example, if the Agency could be convinced that there is a

minimal opportunity for human exposure through one medium or several media,

an  action  level  could  be established at the 1X10sup -2 risk level. This

alternative  was  considered  because  the  Agency  is  concerned about the

possibility that some SWMUs might be triggered into a CMS at the 1X10sup -6

level  even  though  they  do  not  pose  a  threat to human health and the

environment  due  to  a  lack  of  current  and  low  probability of future

exposure.  Although  it  is the Agency's view that the proposed regulations

have enough flexibility to avoid requiring a Corrective Measure Study where

it is not necessary, the Agency is requesting comment on the use of a range

of action levels.



    The  Agency  believes the approach proposed in today's rule provides it

with  the  flexibility  to  require the permittee to investigate corrective

measures  sufficiently  early  (whether  simultaneously  with  the  RFI  or

sequentially)  in  the  corrective  action  process,  while  minimizing the

potential  for  unnecessary  investigations.  Experience  in  the Superfund

program  suggests  that  early  consideration  of potential remedies allows

focused  investigations  and  prevents  delays without imposing unnecessary

resource burdens on either the permittee or the Agency.



    b.  Criteria  for  Determining Action Levels. In several cases, EPA has

promulgated  health-based  standards  appropriate  for  action  levels  for

specific  media.  Where  these  standards are available, EPA intends to use

them  as  action  levels. The most obvious of these are maximum contaminant

levels  (MCLs),  which  establish  drinking  water standards under the Safe

Drinking  Water  Act  (SDWA).  EPA  will  use these standards to set action

levels for ground water, and, in some cases, for surface water.



    In  the  overwhelming majority of cases, however, promulgated standards

will   not  be  available.  Nevertheless,  health-based  levels  that  have

undergone  extensive  scientific  review,  but which have not been formally

promulgated,  are  available  for  many  chemicals. The Agency is proposing

today  in  Sec.  264.521(a)(2)  (i)-(iv) criteria which enable the Regional

Administrator  to  use  such  non-promulgated health-based levels to derive

action levels.



    Concentrations  derived  from non- promulgated health-based levels that

meet the following four criteria included in today's proposal could be used

for  action  levels.  First,  the concentration must be derived in a manner

consistent  with  principles  and procedures set forth in Agency guidelines

for  assessing  the  health  risks  of environmental pollutants, which were

published  in  the  Federal  Register  on  September 24, 1986 (51 FR 33992,

34006,  34014,  34028).  Second,  toxicology  studies used to derive action

levels  must be scientifically valid, conducted in accordance with the Good

Laboratory  Practice  Standards  (40 CFR part 792), or equivalent. The Good

Laboratory  Practice  Standards  prescribe  good  laboratory  practices for

conducting  studies  related  to health effects, environmental effects, and

chemical  fate  testing,  and  are  intended  to  assure  quality  data  of

integrity.  The  guidelines  are for ensuring scientifically valid studies,

and  also may be useful as guidance. In addition, the Agency guidelines for

assessing  the  health risks of environmental pollutants (cited above) cite

several  publications  which  outline procedures for evaluating studies for

scientific  adequacy  and statistical soundness. Third, concentrations used

as  action  levels  must  (for carcinogens) be associated with a 1X10sup -6

upperbound  excess cancer risk for Class A and B carcinogens, and a 1X10sup

-5  upperbound  excess  cancer  risk  for Class C carcinogens. Finally, for

systemic  toxicants  (referring  to  toxic  chemicals {pg 30816} that cause

effects  other  than  cancer  or  mutations),  the  action  level must be a

concentration to which the human population (including sensitive subgroups)

could  be exposed on a daily basis that is likely to be without appreciable

risk  of  adverse  effects during a lifetime. These criteria are similar to

those upon which promulgated health-based standards and criteria are based.

Action   levels  derived  according  to  these  criteria  represent  valid,

reasonable estimates of levels in media at or below which corrective action

is unlikely to be necessary.

    As  mentioned  previously,  guidance  levels  are  available  for  many

chemicals.  Appendix  A  of this preamble lists concentrations for selected

hazardous  constituents  in  water, soil, and air which the Agency believes

meet  these  four  criteria.  EPA  established  these  concentrations by an

assessment  process  which  evaluated the quality and weight-of-evidence of

supporting  toxicological, epidemiological, and clinical studies, and which

relied on the exposure assumptions in appendix D of this preamble.



    The  Agency's  approach to assessing the risks associated with systemic

toxicity   is   different   from   that   for  the  risks  associated  with

carcinogenicity. This is because different mechanisms of action are thought

to  be  involved  in  the two cases. In the case of carcinogens, the Agency

assumes  that  a  small  number  of molecular events can evoke changes in a

single  cell  that  can  lead  to uncontrolled cellular proliferation. This

mechanism  for  carcinogenesis  is  referred  to as ''nonthreshold,'' since

there is essentially no level of exposure for such a chemical that does not

pose  a  small,  but  finite,  possibility  of  generating  a  carcinogenic

response.   In   the   case  of  systemic  toxicity,  organic  homeostatic,

compensating,  and  adaptive  mechanisms exist that must be overcome before

the  toxic  end  point  is  manifested. For example, there could be a large

number  of  cells  performing the same or similar function whose population

must be significantly depleted before the effect is seen.

    The  threshold  concept  is  important  in  the regulatory context. The

individual  threshold  hypothesis holds that a range of exposures from zero

to  some  finite value can be tolerated by the organism with essentially no

chance  of  expression of the toxic effect. Further, it is often prudent to

focus   on  the  most  sensitive  members  of  the  population;  therefore,

regulatory   efforts  are  generally  made  to  keep  exposures  below  the

population  threshold,  which is defined as the lowest of the thresholds of

the individuals within a population.



    Thus,  for  the  chemicals  on  appendix  A  which cause systemic toxic

effects,  the  Agency  has  estimated reference doses (RfDs). The RfD is an

estimate   of   the  daily  exposure  an  individual  (including  sensitive

individuals)  can  experience  without  appreciable  risk of health effects

during  a  lifetime, and is consistent with the threshold concept described

above.



    For the chemicals on appendix A which are believed to cause cancer, the

Agency  has  estimated  carcinogenic slope factors (CSFs). Since the Agency

assumes  that  no  such  threshold  exists for carcinogens, the issue to be

resolved  in  health  assessments  of carcinogens is the probability of the

occurrence  of  an  effect. The CSF, or unit cancer risk, is an estimate of

the  excess  lifetime  risk  due to a continuous constant lifetime exposure

from  one unit of carcinogenic concentration (e.g., mg/kg/day by ingestion,

ug/m  sup 3 by inhalation). Chemicals which cause cancer and mutations also

commonly  evoke  other  toxic  effects.  Thus,  an  RfD and CSF may both be

available  for  a single chemical. In these cases, the level which is lower

(more  protective)  should  be  used  as  an  action  level. Generally, the

protective level for cancer will be lower.



    For  carcinogens,  EPA  believes  that action levels corresponding to a

1X10sup -6 risk level (or 1X10sup -5 for Class C carcinogens) generally are

appropriate.  This is at the higher protective end of the 10sup -4 to 10sup

-6  risk  range.  (See  discussion  in section VI.F.5 of today's preamble.)

Using  a  value  from the high end of this range ensures that the hazardous

constituents  screened  out  at  this  point are those for which corrective

measures are unlikely to be necessary.



    In  adopting  the 1X10sup -4 to 1X10sup -6 risk range for this proposed

rule, the Agency recognized that 1X10sup -4 risk levels of constituents may

not  be  protective  at  all  sites, due to multiple constituents, multiple

exposure pathways, or other site-specific factors.



    Thus,  the  alternative  of  establishing  actions  levels at the lower

protective  end  of the risk range (e.g., 1X10sup -4) was rejected since it

would  be  too  insensitive  a  trigger-i.e.,  it  would  fail to require a

Corrective  Measure  Study  at  some sites which may pose a threat to human

health  and  the  environment.  The  Agency believes that the selected risk

levels are reasonable points to establish action levels for carcinogens.



    Section  264.521(a)(2)(iii)  provides  some flexibility to the Regional

Administrator to consider the overall weight of evidence of carcinogenicity

in   setting   action   levels  for  carcinogens.  EPA  has  explained  its

classification  scheme  for carcinogens based on the weight of evidence for

carcinogenicity  in  its  cancer  guidelines (51 FR 33992). The constituent

concentrations provided as example action levels in appendix A reflect this

approach.  In  this  table,  known  or probable human carcinogens (known as

Class A and Class B carcinogens, respectively, under the Agency guidelines)

are  listed  at  a 1X10sup -6 risk level, whereas concentrations listed for

constituents  for which the weight of evidence of carcinogenicity is weaker

(known  as  Class  C,  or  possible  human  carcinogens  under the Agency's

guidelines),  correspond  to  a  1X10sup  -5  risk level. Some experts have

argued  that it is inappropriate to weight Class C carcinogens in this way,

and  that  all  substances  classified  as  carcinogens  should be weighted

equally,  whereas  others argue that Class C carcinogens should be weighted

more  heavily  (i.e.,  more stringently) because of the greater uncertainty

associated  with  the limited evidence of their carcinogenicity. The Agency

solicits  comments  on  how it should handle Class C carcinogens in setting

action levels.



    Many  of  the RfDs and CSFs used to derive the concentrations listed in

appendix  A  are  available  through the Integrated Risk Information System

(IRIS),  a computer-housed, electronically communicated catalogue of Agency

risk  assessment  and  risk management information for chemical substances.

IRIS  is  designed  especially  for Federal, State, and local environmental

health  agencies  as a source of the latest information about Agency health

assessments  and regulatory decisions for specific chemicals. (To establish

an  IRIS  account,  call  Dialcom  at  (202) 488-0550.) The risk assessment

information (i.e., RfDs and CSFs) contained in IRIS, except as specifically

noted, has been reviewed and agreed upon by intra-agency review groups, and

represents  an  Agency  consensus. As EPA working groups continue to review

and verify risk assessment values, additional chemicals and data components

will be added to IRIS. IRIS hardcopy will be available through the National

Technical  Information  Service  (NTIS).  In  addition,  EPA will routinely

update appendix A as new data on hazardous constituents are developed.



    c. Action Levels for Ground Water. Proposed Sec. 264.521(a) establishes

action  levels  for  ground  water  in  aquifers.  By  specifying  the term

''aquifer''  in this context, the Agency intends to define broadly the type

of  ground-  water  {pg  30817}  contamination  situations that may require

Corrective   Measure   Studies,  while  triggering  such  studies  only  in

situations  where  actual  ground-water  cleanup  is  a reasonable remedial

approach.



    The Agency considered using the term ''uppermost aquifer,'' but decided

that  this would limit its flexibility in addressing contamination in lower

aquifers  that  are not hydraulically connected with the uppermost aquifer.

Such  a  situation  could  arise if waste were leaked from the casing of an

underground  injection  well.  Thus,  the  wording  of Sec. 264.521(a) will

explicitly  allow  the  Agency  to address any such unusual instances where

solid  waste management units have contaminated ground water that is not in

an ''uppermost'' aquifer as defined in Sec. 264.510.



    The  Agency  also  considered  not  using  the term ''aquifer'' in Sec.

264.521(a).  This would have required Corrective Measure Studies for ground

water  to be performed even when the ground water is of negligible use as a

resource,  such  as  a  small  pocket  of soil which becomes saturated only

episodically.  Although  contamination in any saturated zone that could act

as  a pathway transporting contaminants to aquifers could be a concern, the

Agency  would  intend to address those situations in the context of setting

action  levels  for  soils  (see Sec. 264.521(d)), including ''deep soils''

that could act as a ground- water contaminant pathway.



    EPA has, under a number of statutes, promulgated standards and criteria

relevant  to protection of environmental media. Among the most important of

these  are  maximum  contaminant  levels  (MCLs) promulgated under the Safe

Drinking  Water  Act  (42  U.S.C.  section 300(f) et seq.), which have been

incorporated  into  this  rule as action levels for ground water under Sec.

264.521(a)(1).  MCLs  promulgated  under  the  Safe  Drinking Water Act are

maximum  concentrations  of contaminants allowed in water used for drinking

(see  appendix  B).  The  use  of MCLs for action levels is consistent with

current  RCRA  ground-water  protection standards (40 CFR part 264, subpart

F),  which  set  the interim primary drinking water standards (MCLs) for 14

constituents  (which  existed  at  the  time  subpart  F  regulations  were

promulgated) as ground-water protection standards in the absence of another

Agency  decision. Currently there are 34 MCLs promulgated, of which six are

microbiological  contaminants,  three are radionuclides, and 25 are organic

and  inorganic  contaminants;  the  MCLs  for the chemical contaminants are

listed in appendix B.



    Where  MCLs  are  available for a particular constituent but the ground

water  at  a site is not currently used for a drinking water supply, and is

unsuitable  for  use  as  a  drinking water supply in the future, MCLs will

still  ordinarily  be  used  as  action  levels  (i.e.,  to require a CMS);

however,  cleanup  to the MCL might not be required (see section VI.F.5 for

discussion  of  media  cleanup standards). The Agency is persuaded that, in

cases  where  ground  water  is contaminated at levels above action levels,

further study is necessary (e.g., to make sure that sources of releases are

controlled).



    Where  MCLs  have  not been promulgated for hazardous constituents, EPA

would  develop  levels according to the criteria specified in proposed Sec.

264.521(a)(2)(i)-(iv)  and  described in detail above in this preamble (see

section  VI.E.2.b).  In  this  analysis,  the Agency would use the standard

exposure  assumptions of two liters a day for a 70 kilogram adult over a 70

year  lifetime  (see  appendix  D),  assumptions  that are used extensively

throughout  EPA  and  other  agencies.  Appendix  A  lists levels that were

developed  for  water by the Agency according to these principles and which

the Agency believes would be appropriate for ground-water action levels. In

addition, proposed (but not yet promulgated) MCLs would also typically meet

the  criteria  proposed  in  Sec.  264.521(a)(2)(i)-(iv) and could serve as

ground-water action levels.



    Where data are insufficient to develop action levels according to these

criteria,  the Agency would establish levels according to the procedures in

proposed  Sec.  264.521(e),  which  are described in more detail in section

VI.E.2.g  of  this  preamble.  The  Agency solicits comment on the proposed

approach  and  alternative  approaches  to  establishing  action levels for

ground water.



    d.  Action Levels for Air. Proposed Sec. 264.521(b) identifies criteria

for   establishing   action  levels  for  air,  assuming  exposure  through

inhalation  of  air contaminated with the hazardous constituent. Appendix A

lists  possible action levels that meet these criteria. The Agency used the

following procedures to develop concentrations in air listed in appendix A:



    Note: Appendix A action levels are currently taken exclusively from the

IRIS  data base, and developed using only procedures 1 and 4; this appendix

will  be  modified  to  include other health-based numbers not currently on

IRIS,  derived  from  procedures  2  and 3. This is consistent with current

Superfund practices and policy.



    1.  Where  an  Agency-verified health-based intake level for inhalation

(e.g.,   RfD)   was  available,  that  level  was  used  to  calculate  the

concentration in air.



    2.  Where  an  Agency-  verified  level  (as  in  (1),  above)  was not

available,  a  level based on a valid inhalation study was used, even if it

had not yet gone through the formal intra-Agency verification process.



    3. If a level based on an inhalation study (as in (1) or (2) above) was

not  available,  a  health-based  intake level (e.g., RfD) based on an oral

study  was  used,  with  a  conversion  factor  of  one  for route-to-route

extrapolation  to  calculate  the concentration in air-except where such an

extrapolation factor was determined to be inappropriate. For example, it is

not appropriate where a constituent that is a systemic toxicant through the

oral route of exposure causes local adverse effects on the lung through the

inhalation  route.  A  constituent  might  also  be  determined  to  be  an

inappropriate candidate for route-to-route extrapolation due to significant

differences  in metabolism or absorption. Where the extrapolation from oral

route  to  inhalation  route of exposure is determined to be inappropriate,

and  a  level  based on an inhalation study (as in (1) or (2) above) is not

available,  appendix  A  does  not list a concentration in air (see section

VI.E.2.g  for  a  discussion  of how to set action levels where health- and

environment-based  levels  are  not available). While the concentrations in

air  listed in appendix A (and C) are being evaluated further by the Agency

with  regard  to  the appropriateness of this route-to-route extrapolation,

they  will  be  used only as an interim measure. The Agency will adopt RfDs

based  on  actual  inhalation  toxicity  data  as  soon  as the data become

available.



    4.  The  standard  exposure assumption for air typically used in Agency

risk assessments (i.e., 20m sup 3/day for a 70 kilogram adult for a 70 year

lifetime) was used (see appendix D).



    Under  proposed  Sec. 264.521(a)(2), action levels would be measured or

estimated  at the facility boundary, or another location closer to the unit

if necessary to protect human health and the environment.



    The  Agency  has chosen the facility boundary as the location where air

action  levels  are proposed to be typically measured, for several reasons.

Measuring  at  the  facility  boundary  will  have  the effect of requiring

Corrective   Measure   Studies   to   be   conducted  whenever  potentially

health-threatening  levels  of  airborne  constituents  that originate from

waste  management  units {pg 30818} are being released to areas outside the

facility  property.  The  Agency  recognizes  that in some cases this could

require  owner/operators to study potential remedial solutions where actual

remediation  of  air  releases will not be required-under today's proposal,

the  requirement  actually  to  remediate  air  releases  is tied to actual

exposure;  i.e.,  exceedence  of  health-based  levels  at the most exposed

individual (see the discussion of air cleanup standards in section VI.F.7.a

of  today's preamble). However, under this scenario, if exposure conditions

were  to subsequently change and trigger the need for corrective action for

air  emissions,  the  owner/operator  would  be  able to more expeditiously

implement  the  remedy  that  had  already been developed in the Corrective

Measure  Study.  The  Agency  believes  that measuring action levels at the

facility  boundary,  while environmentally conservative, will not represent

an undue burden on owner/operators.



    Under   today's   proposal,  the  Regional  Administrator  could,  when

necessary,  require  action  levels to be measured at one or more locations

within  the  facility.  An  example  would  be if individuals were actually

residing  on  the  facility  property,  as  might  be the case at a Federal

facility  (e.g.,  a  military  base).  On-site  worker  exposure  would not

generally  be  a  determining  factor  in establishing locations for action

levels,  since  such  exposure  is regulated by the Occupational Safety and

Health  Administration  (see  further  discussion in section VI.F.7.a(2) of

today's preamble).



    The  Agency  considered,  but  did  not  propose,  other  locations for

establishing  action  levels  for air releases. These alternative locations

would  have involved determining action levels at (1) the unit boundary, or

(2)  the  most  exposed  individual.  The alternative of determining action

levels  at the unit boundary was rejected as unnecessarily stringent, since

it  would  likely  have  the effect of very often triggering the need for a

Corrective  Measure  Study,  where  no  actual or potential threat to human

health  and  the environment existed. The option of measuring action levels

at  the  most exposed individual was not chosen because in some cases a CMS

would not be triggered based on current locations of receptors, even though

future residential development close to the facility were planned and could

result  in  exposure  above action levels. The Agency specifically requests

comment  on  the  most appropriate location for measuring action levels for

the air medium.



    e. Action Levels for Surface Water. Proposed Sec. 264.521(c) identifies

action  levels for surface water. Notwithstanding these action levels, some

releases  from solid waste management units to surface water may be subject

to  the National Pollutant Discharge Elimination System (NPDES) pursuant to

section 402 of the Clean Water Act (CWA). The CWA prohibits the unregulated

discharge  of  any  pollutant to waters of the United States from any point

source. Releases to surface waters that are nonpoint sources may be subject

to  the  Nonpoint  Source Management Program established under sections 208

and  319  of  the  CWA.  If  the Agency discovers releases from solid waste

management  units  which  are  point sources, but lack an NPDES permit, CWA

authorities  will  generally  be  used to address the release. It should be

understood  that  the term surface water in this context includes wetlands,

as  prescribed  under  section  404  of  the  CWA.  Section 404 permits are

required for dredge and/or fill into wetlands.



    Proposed  Sec.  264.521(c) specifies that State water quality standards

established  pursuant  to  section  303  of  the  CWA that are expressed as

numerical  values  will  be  used  as  action  levels, where they have been

established   for   the  surface  water  body  in  question.  However,  EPA

anticipates that such numerical standards may, in some cases, not have been

established at the time when remedial investigations are being conducted at

RCRA  facilities.  In  these  cases,  action  levels  may be established as

numeric interpretations of State narrative water quality standards.



    Water  quality  standards both establish water quality goals, and serve

as  a  basis  for establishing treatment controls, based on the use or uses

which  the  State  designates  for the receiving water (e.g., recreation or

public  water  supply).  The standards consist of a designated use or uses,

and  the  water quality criteria which will protect such uses. Criteria are

expressed  as  either numeric constituent concentration levels or narrative

statements  that  represent  a  quality of water that supports a particular

use.

    In  applying  narrative standards to specific water bodies, some States

have  prescribed methods for calculating numeric values for the water body.

Such  methods  vary  from  State  to  State  in  their complexity, the time

required  to  establish  the  numeric  values, and the procedures involved.

Although  deriving  these  numeric interpretations from narrative standards

will  often  be straightforward, the Agency expects that in some situations

the   derivation   of   such   values   could  be  relatively  complex  and

time-intensive.  In  such cases, the Regional Administrator could determine

that  the  use  of  numeric  interpretations  of  narrative  water  quality

standards  was  not  appropriate  for  the  purpose  of establishing action

levels.  EPA  emphasizes  that the use of such narrative standards must not

delay the corrective action process.



    Where  numeric water quality standards have not been established by the

State,  and where numeric interpretations of narrative standards are either

unavailable  or  inappropriate (for reasons described above), proposed Sec.

264.521(c)(3)  provides  that maximum contaminant levels (MCLs) promulgated

under  the  Safe  Drinking  Water Act will be used as action levels, if the

surface  water  has been designated as a drinking water source by the State

(see  discussion in previous section on the use of MCLs as action levels in

ground water).

    In  situations  where  a  numerical  water  quality standard, a numeric

interpretation  of  narrative  standards,  or an MCL is not available for a

particular  hazardous  constituent in surface water designated by the State

for drinking, proposed Sec. 264.524(c)(4) specifies that the criteria under

Sec.  264.521(a)(2)  (i)-(iv)  be  used  for  establishing action levels in

surface   water,   assuming  exposure  through  consumption  of  the  water

contaminated   with   the  hazardous  constituent.  The  standard  exposure

assumptions  of two liters/day for a 70 kg adult over a 70 year lifetime in

appendix  D  should  be  used, unless people also consume aquatic organisms

from  the  surface  water. In these cases, the Agency suggests that Federal

Water  Quality  Criteria  be  used as action levels, since they satisfy the

criteria  for  action levels established under Sec. 264.521(a)(2) (i)-(iv).

Federal   Water   Quality   Criteria  are  concentrations  of  contaminants

determined  to  be  protective  of  human  health and/or aquatic organisms.

Criteria  for  protection  of  human  health  are based on exposure through

drinking  water,  as  well as exposure through drinking water and ingesting

aquatic  organisms.  Criteria  for  protection  of freshwater/estuarine and

marine  organisms  are  also  available.  EPA has promulgated water quality

criteria for 126 pollutants under the Clean Water Act.



    In situations where a numerical water quality standard is not available

for  a  particular hazardous constituent in surface water designated by the

State  for  uses  other than drinking, proposed Sec. 264.524(c)(5) provides

the  Regional {pg 30819} Administrator with the flexibility to consider the

State-designated  use  of the surface water in establishing a concentration

as  the  action  level.  For example, in some surface waters designated for

industrial  uses,  the  Agency  believes that an MCL may be too sensitive a

trigger  for  a  CMS.  In  other  situations, MCLs may be too insensitive a

trigger  for  a  CMS (for example, in trout streams). Federal Water Quality

Criteria  may  provide  useful guidance in setting action levels under Sec.

264.524(c)(5).



    If  Federal  Water  Quality  Criteria  are  used  as action levels, the

purposes  for  which  such  criteria were developed should be considered in

determining  which  criteria  are  appropriate  to  use. For example, for a

surface  water  body  used  for  fishing  and  drinking,  the  criteria for

protection  of  human  health  based  on  drinking water and eating aquatic

organisms  would  be most appropriate. For Class A and Class B carcinogens,

the criteria corresponding to a 10sup -6 risk level should be used, whereas

for   Class   G   carcinogens,   the  Agency  suggests  that  the  criteria

corresponding   to  10sup  -5  risk  level  be  used.  (See  discussion  of

Agency-established   classes   of  carcinogens  and  relative  risk  levels

considered appropriate in section VI.E.2.c of this preamble.)

    If  contaminants  attributable to releases from a SWMU exceed an action

level  anywhere  in  surface  water,  a  Corrective  Measure  Study  may be

required. Proposed Sec. 264.521(c) does not specify where in surface waters

concentrations  should  be  measured  against action levels. In determining

appropriate  sampling  locations,  the  Agency  will  generally  attempt to

specify  locations in the surface water where the highest concentrations of

hazardous  constituents  released from SWMUs are expected to occur-i.e., at

or  near  the  point  or  points  where  releases  enter the surface water.

However,  in  some  cases, establishing the precise point(s) where releases

enter the surface water may be difficult and time-consuming, such as in the

case  of a ground-water plume in a complex hydrogeologic setting that flows

into  a  lake.  In  these  cases,  the  Agency  would not wish to delay the

initiation  of  a  Corrective  Measure  Study while the point of release is

located,  if  concentrations  greater  than  action levels could already be

detected in the surface water.



    EPA  specifically requests comment on today's proposal for establishing

action levels for surface water.



    Proposed  Sec.  264.520(b),  which allows the Regional Administrator to

require  a  CMS when necessary to protect human health and the environment,

even  when  no  action  levels  have  been  exceeded,  may  be particularly

important  for  surface  water. For example, the Regional Administrator may

determine  that  a  threat  from consumption of aquatic organisms exists at

levels  at  or  below  the MCL, since the MCL does not incorporate exposure

through ingestion of contaminated organisms.



    A  Corrective  Measure Study may also be required under Sec. 264.520(b)

if  the  Regional  Administrator determines that there is a threat to human

health  or  the  environment from contaminated sediments even though action

levels  for surface water have not been exceeded. The Agency believes it is

important  to  clarify  its  authority to address sediments contaminated by

releases  from solid waste management units under sections 3004 (u) and (v)

of  HSWA,  although  today's  proposal  does  not  establish  action levels

specifically  for  sediments.  The  Agency is currently developing sediment

criteria  which,  when  promulgated,  may be used as guidance in evaluating

contaminated  sediments.  However,  no health-based or environmental levels

are  currently  available  which are appropriate as sediment action levels.

Thus,  until  such  criteria are developed, the need for Corrective Measure

Studies   based   on   sediment  contamination  will  be  determined  on  a

case-by-case  basis.  The  Agency  requests  comment  on  this  approach to

addressing sediments.



    Finally,  the  Regional  Administrator may require a Corrective Measure

Study  for  surface  water  under  Sec. 264.520(b) when a threat to aquatic

health  exists  at  levels at or below action levels. Federal Water Quality

Criteria  for  protection  of  aquatic health should be used as guidance in

making this determination.



    f.  Action  Levels  for  Soil.  Proposed  Sec.  264.521(d)  establishes

criteria for establishing action levels for soil, assuming exposure through

consumption of the soil contaminated with the hazardous constituent. Action

levels would be set on the basis of the exposure assumptions in appendix D,

which  assume  a residential use pattern, with long-term direct contact and

soil  ingestion  by  children.  Action  levels  for soil would typically be

measured on the surface (generally the upper two feet of earth).



    The  exception  to  this approach, is where EPA has already established

standards  for  the  cleanup  of  spilled polychlorinated biphenyls (PCBs),

which  are  regulated  under  the  Toxic Substances Control Act (TSCA). The

Agency  has  determined  that  the  use  of these promulgated standards, as

action  levels  and  cleanup  standards  for  soil,  is  relevant  to  RCRA

corrective  action.  This  policy is also consistent with Superfund policy.

The PCB Spill Policy under TSCA is discussed more fully in section VII.B of

this preamble.

    Although  action  levels for soils are established using direct contact

assumptions most appropriate for surficial soils, it is intended that these

action  levels  will  often also be used as a presumption that a GMS may be

necessary  for  contaminated  deep  soils which may pose a threat to ground

water  in  aquifers. The Agency does not believe that generic action levels

based  on  the  potential for hazardous constituents in soil to contaminate

ground  water  can  be  developed  at  this  time,  since the type of soil,

distance  to  ground water, and other site-specific factors, as well as the

properties  of  the  hazardous  constituent,  influence  this  potential. A

permittee may attempt to rebut this presumption by demonstrating that there

is  no  threat  to  human  health  and  the environment from such deep soil

contamination,  either  through  direct contact or migration to aquifers or

surface  water. Alternatively, Sec. 264.520(b) may be used to require a CMS

in  situations  where  deep soils are contaminated below action levels, but

pose a threat to ground water in aquifers.



    Although  estimates  of  soil  intake are not as frequently used by the

Agency  as  are  estimates  of  air  or  water  intake, appendix D provides

recommended exposure assumptions for non-carcinogenic and carcinogenic soil

contaminants  given  an unrestricted use scenario. A soil ingestion rate of

0.1 g/day is recommended for carcinogens, and a rate of 0.2 g/day, based on

an  average  child's  body  weight  of  16  kg,  is  recommended  for  non-

carcinogens.



    In  the  case  of  non-carcinogenic contaminants, the oral RfD would be

used  to  calculate an action level, or threshold concentration below which

adverse  effects  would  not  occur,  assuming  0.2 gram per day of soil is

consumed.  Sixteen kilograms represents an average body weight for children

aged  one  to  six.  The  Agency  believes  these  exposure assumptions are

reflective  of  a  conservative average scenario in which children ages 1-6

years  (i.e.,  the  time  period during which children exhibit the greatest

tendency   for   hand-   to-mouth   activity)  are  assumed  to  ingest  an

above-average  amount  of  soil  on  a  daily  basis.  The  exposure levels

estimated  in  this  manner are calculated to keep exposures well below the

population   ''threshold''   for   toxic   effects  (see  earlier  preamble

discussion). Since the toxic effect of concern is assumed to occur once the

threshold  {pg  30820}  level is exceeded, the amount of soil ingested on a

daily  basis  becomes  of major importance in determining non- carcinogenic

effects. Therefore, to account properly for the risk from elevated exposure

to  non-carcinogenic  soil contaminants during early childhood years, it is

important  that  the  exposure  not  be estimated over a lifetime; to do so

would  ''smear'' out the peak exposure occurring during the above-mentioned

time  period  of  five  years  and  result  in  the  failure  to  detect an

unacceptable exposure level (i.e., a level which exceeds the RfD).

    In  the  case  of  carcinogens,  the  action  level would be derived by

assuming consumption of 0.1 g/day averaged out over a lifetime, based on an

adult  body  weight of 70 kilograms. Because the expression of carcinogenic

effects is principally a function of cumulative dose (i.e., the time course

of  exposure  is  usually secondary), the Agency believes, in general, that

elevated  exposures  during  early  childhood are relatively unimportant in

determining  lifetime  cancer  risk. Therefore, total lifetime (cumulative)

soil  ingestion  can  be averaged to derive a per day value. These exposure

assumptions do, however, reflect a reasonable worst-case scenario-0.1 g/day

is an upper-range estimate of soil ingestion for older children and adults.



    The  above  recommendations  are  based on the conservative assumptions

that  100  percent  of  the ingested non-carcinogenic and carcinogenic soil

contaminants  are  absorbed  across  the  gastrointestinal  tract  and that

ingestion  occurs  365 days/year, regardless of climatic conditions or age.

The  Agency solicits comment on the above assumptions for soil exposure for

establishing action levels.



    The Agency considered the use of other generic exposure assumptions for

establishing action levels for soil based on direct contact (e.g., exposure

through  dermal contact, exposure through ingestion under a non-residential

scenario),  but  rejected  these  alternatives  for several reasons. First,

establishing action levels based on generic assumptions for dermal exposure

or exposure via ingestion of soil under a non-residential scenario would be

a  far  less  sensitive  trigger,  and  could  in  effect  cause  a ''false

negative''  in situations where the Agency believes corrective action would

be  necessary.  Second, the data base for developing action levels based on

dermal  exposure  or exposure via ingestion of soil under a non-residential

exposure scenario is limited.



    In  addition  to  considering  generic exposure assumptions, the Agency

considered  the  use  of site-specific, direct contact exposure factors for

deriving  soil  action  levels. However, the Agency believes that assessing

site-specific    exposure   in   setting   action   levels   would   be   a

resource-intensive process, and would run counter to the objective of using

action  levels  as a simple screening mechanism. The Agency recognizes that

the  proposed  approach  is conservative. Nevertheless, the Agency believes

that  these  levels are appropriate as action levels (as opposed to cleanup

targets)-that is, they can reasonably serve as rebuttable presumptions that

further study, including analysis of possible remedies, is necessary.



    Soil  cleanup  levels are discussed in more detail in section VI.F.5 of

this  preamble.  However, it should be recognized that facilities with soil

contamination  above  an  action  level-particularly where the levels would

pose no threat under current conditions of exposure-would have a wide range

of  remedial  options open to them, including ''conditional'' remedies (for

which  the  permit  would  specify  appropriate  exposure controls), or the

covering  of  the  contaminated  soil  with  a  soil  cap.  In this case, a

Corrective  Measure  Study  might  simply  be  a  proposal  to  clean up to

protective  levels,  assuming industrial land use, and to ensure restricted

access for the life of the permit. This raises the issue of ''conditional''

remedies,  which  is  discussed  in  more  detail in section VI.F.8 of this

preamble.



    g.  Action  Levels Where Health- and Environmental-Based Levels Are Not

Available. If, for any medium, Agency-promulgated standards or criteria, or

other  health-based  levels meeting the proposed criteria are not available

or cannot be developed for use as action levels, Sec. 264.521(e) allows the

Regional  Administrator  to  set an action level for any constituent on the

basis  of  available  data  and  reasonable worst-case assumptions. In most

cases,  partial  data or data on structural analogs will allow the Regional

Administrator  to  estimate  whether the detected level of a contaminant is

likely  to  cause  a  problem.  In  other cases, other contaminants will be

present at high levels (triggering a CMS in any case), and it will be clear

that the constituent is not a driving factor in determining the risk at the

site,  even  under  worst-case assumptions concerning its toxicity. In such

cases  it  may  not  be  necessary  to  specify  an  action  level  for the

constituent.  Finally,  under  proposed  Sec.  264. 521(e)(2), the Regional

Administrator  would  have  the  authority  to  set  the  action  level  at

background  for  a  hazardous constituent for which data were inadequate to

set  a  health- or environment-based action level. This option, however, is

providad  primarily  as  a fall- back position. The Agency believes that it

will very rarely be necessary to set action levels at background.



    As  indicated  earlier,  appendix  A lists possible action levels for a

range  of  hazardous  constituents  based  on the criteria proposed in Sec.

264.521(a)(2).  EPA's  Office of Solid Waste, OSW (renamed Office of Resource Conservation and Recovery, ORCR, on January 18, 2009) is developing, for the

purpose of guidance, health-based numbers on additional constituents. These

levels  would  also satisfy the criteria of proposed Sec. 264.521(a)(2). As

these  additional  health-based  levels are developed, they will be entered

into  tha  Integrated  Risk  Information  System (IRIS). For information on

these   guidance   numbers,  the  OSW  Technical  Assessment  Branch/Health

Assessment Section should be consulted at (202) 382-4761.



    h.  Authority  to Require a Corrective Measure Study Where Action Level

Have  Not Been Exceeded. The Agency believes it is important to provide the

Regional  Administrator  authority  to  require a CMS under Sec. 264.520(b)

even when no constituents exceed action levels. For example, a CMS could be

required  if there are threats to certain sensitive environmental receptors

at  a  particular  facility  with  contamination at or below action levels.

Also,  a  CMS  could  be required in situations where the risk posed by the

presence  of  multiple  contaminants  may  be  high  enough  to  warrant  a

Corrective  Measure  Study  even  if  no  single  constituent  exceeds  the

individual  action  level  for  the  constituent. Similarly, if individuals

living near the site are receiving significant exposures from sources other

than  SWMUs  at the site, the incremental exposure due to SWMUs at the site

may result in a cumulative risk large enough to warrant a CMS. In addition,

there may be situations where ''cross-media'' risks could indicate the need

for  a  CMS, even though action levels in a particular medium have not been

exceeded.  An  example might be where at nearby residences releases in both

the air and ground water are present at very low levels, but the cumulative

risks  from  both  pathways  of  exposure  are sufficiant to be of concern.

Although  such  situations  are  expected to be relatively rare, the Agency

will  examine such cross-media risks when site-specific conditions indicate

the potential for such exposure factors.



    A  CMS  may  also  be  required  if  constituents pose a threat through

exposure  pathways  other  than  that assumed in setting action levels. For

example,  constituents  in  surface water that do not exceed MCLs may still

pose  {pg  30821}  a  threat  to  persons  who ingest fish caught from that

surface  water.  Constituents  in  ground water that do not exceed MCLs may

still  pose a threat through ponding or basement seepage. Nevertheless, the

Agency  believes  that, with few exceptions, proposed action levels will be

adequate  to identify potential threats to human health and the environment

which necessitate a CMS.



    3.  Scope  of  Corrective  Measure  Study  (Sec.  264.522). In the RCRA

program,  corrective  action requirements will be implemented at facilities

with  a  wide range of different types of environmental problems. Some RCRA

facilities  might,  if  evaluated  according  to Superfund's Hazard Ranking

System  (HRS),  score  high  enough to be included on the National Priority

List.  On  the  other  hand,  most RCRA facilities have much less extensive

environmental  problems,  and are maintained by viable owner/operators, who

may  be  expected  to  operate  at the site for an extended period of time.

Recognizing  the  diversity of the RCRA facility universe, today's proposal

has  been  structured  to  provide  the  Agency considerable flexibility in

defining  the  scope and analytic approach to developing Corrective Measure

Studies,  consistent  with  the  extent  and  nature  of  the environmental

problems at the facility.



    EPA  anticipates  that for most RCRA facilities, the studies needed for

developing  sound,  environmentally  protective  remedies can be relatively

straightforward,  and  may  not require extensive evaluation of a number of

remedial  alternatives. Such ''streamlined'' Corrective Measure Studies can

be  tailored  to  fit  the  complexity  and scope of the remedial situation

presented  by  the facility. For example, if the environmental problem at a

facility   were   limited   to   a  small  area  of  soils  with  low-level

contamination,  the  Corrective  Measure Study might be limited to a single

treatment  approach  that  is  known  to  be  effective  for  such types of

contamination.   In   a   different   situation,   such  as  with  a  large

municipal-type  landfill, it may be obvious that the source control element

of the CMS should be focused on containment options. EPA anticipates that a

streamlined  or  highly  focused  CMS  will be appropriate to the following

types of situations:



     ''Low  risk''  facilities. Facilities where environmental problems are

relatively small, and where releases present minimal exposure concerns.



     High  quality  remedy  proposed by the owner/operator. Owner/operators

may propose a remedy which is highly protective (e.g., equivalent to a RCRA

''clean  closure''),  and  which  is  consistent  with  all  other remedial

objectives (reliability, etc.).



     Facilities  with  few  remedial options. This would include situations

where  there  are  few practicable cleanup solutions (e.g., large municipal

landfills), or where anticipated future uses of the property dictate a high

degree of treatment to achieve very low levels of residual contamination.



     Facilities   with   straightforward   remedial   solutions.  For  some

contamination  problems, standard engineering solutions can be applied that

have proven effective in similar situations. An example might be cleanup of

soils contaminated with PCBs.



     Phased  remedies.  At  some facilities the nature of the environmental

problem  will  dictate  development  of  the  remedy  in  phases,  (see the

discussion  of phased approach under Sec. 264.526(d)), which would focus on

one  aspect  (e.g., ground-water remediation) of the remedy, or one area of

the   facility   that   deserves  immediate  measures  to  control  further

environmental  degradation  or  exposure problems. In these situations, the

Corrective  Measure  Study would be focused on that specific element of the

overall  remedy,  with  follow-on  studies  as appropriate to deal with the

remaining remedial needs at the facility.



    EPA  recognizes  that,  in  contrast  to  the  above  situations,  some

facilities  with  very  extensive  or highly complex environmental problems

will require Corrective Measure Studies that assess a number of alternative

remedial   technologies  or  approaches.  The  following  are  examples  of

situations  which would likely need relatively extensive studies to be done

to support sound remedy selection decisions:



     ''High   risk''   facility   with  complex  remedial  solutions.  Such

facilities  might  have  large  volumes  of  both  concentrated  wastes and

contaminated  soils,  for  which  several  different treatment technologies

could  be  applied  to  achieve  varying  degrees  of  effectiveness (i.e.,

reduction  of  toxicity  or volume), in conjunction with different types of

containment systems for residuals.



     Contaminant  problems for which several, very different approaches are

practicable.  There may be several, quite distinct technical approaches for

remediating  a  problem at a facility, each of which offers varying degrees

of  long-term  reliability,  and  would  be implemented over different time

frames,  with  substantially  different  associated  cost  impacts. In such

cases,  remedy  selection  decisions  will  necessarily involve a difficult

balancing  of  competing  goals  and  interests.  Such  decisions  must  be

supported with adequate information.



    In  addition  to  the above examples of situations calling for either a

limited,  or  relatively complex CMS, other studies will fall in the middle

of   that  range.  Given  this  ''continuum''  of  possible  approaches  to

structuring   Corrective  Measure  Studies,  it  is  the  Agency's  general

intention to focus these studies on plausible remedies, tailoring the scope

and substance of the study to fit the complexity of the situation.



    The  general  types  of  analyses and information requirements that may

potentially be required of the permittee in conducting a Corrective Measure

Study  are  outlined  in  today's  proposed Sec. 264.522(a). Note that this

provision  does  not  prescribe  that  any  specific  types  of remedies be

analyzed,  nor  does  it  define  a  decision  process  by  which  remedial

alternatives  are  ''screened'' or evaluated. It is intended to provide the

decisionmaker  with  a  range of options for structuring a study to support

the ultimate remedy selection for the facility.



    Proposed Sec. 264.522(a)(1) lists items that the Regional Administrator

may  require  in  a CMS for any remedy(s) evaluated. In general, sufficient

information  should be provided for the Agency to determine that the remedy

selected can meet the remedy standards of Sec. 264.525(a).



    Section  264.522(a)(1)  would give the Regional Administrator authority

to  require  the  permittee  to  perform  an evaluation of the performance,

reliability,   ease  of  implementation,  and  impacts  (including  safety,

cross-media  contaminant  transfer,  and  control  of exposures to residual

contamination)   associated   with   any  potential  remedy  evaluated.  In

evaluating  the  performance  of  each  remedy, the Agency would expect the

permittee to evaluate the appropriateness of specific remedial technologies

to  the  contamination  problem  being  addressed  and the ability of those

technologies  to  achieve  target  cleanup  concentrations  (per  following

discussion on ''target levels'').



    To evaluate these factors for a specific remedy, the owner/operator may

be  required  to  develop specific data. Data may be needed on general site

conditions,  waste  characteristics,  site  geology,  soil characteristics,

ground-water  characteristics,  surface water characteristics, and climate.

The   Agency   anticipates  that  permittees  will  collect  much  of  this

information  during remedial investigations required under Sec. 264.510. In

some  cases,  important  relevant information may be included in the part B

application.  To the extent that potential remedies are identified early in

the remedial investigation process, the permittee can streamline his or her

data  collection  efforts  to  include  data  needed  for the evaluation of

specific remedial alternatives.



    Analysis  of  a  remedy's performance and reliability should include an

assessment  of  the  effectiveness of a remedy in controlling the source of

{pg  30822}  release  and  its  long-term  reliability.  Where treatment is

planned,  an  assessment  of treatment capability should be provided; where

waste  will  be managed on-site, the details of the management (including a

description  of  the units in which it is treated or disposed of) should be

supplied.  Potential  safety  impacts  (e.g.,  associated  with excavation,

transportation,  etc.)  of  the  remedy  should  also be considered in most

cases. Further, the Agency may require information on implementability-such

as  capacity  availability  or  State  or local permitting requirements- to

determine whether a remedy is feasible.



    The  Agency  is  particularly  concerned  about  potential  cross-media

impacts  (intermedia  transfer  of contaminants) of remedies, and therefore

specifically  identified  them  as  an  area  that  may  require  study. In

addition,  cross-media  impacts  will  be  one of the factors considered in

remedy  selection  (see  proposed Sec. 264.525). Some remedial technologies

may  cause secondary impacts that must be considered in selecting remedies.

For  example,  in  some  circumstances,  air  stripping of volatile organic

compounds (VOCs) from ground water may release these VOCs to the air unless

specific  emission  control  devices are installed on the air stripper. The

Corrective  Measure  Study  should  also  determine  whether  other adverse

impacts  from a potential remedy will reduce its effectiveness in achieving

the  cleanup goal. For example, removal of contaminated sediments in large,

slow-moving  rivers  may  resuspend  sediments  and  cause  more  harm than

allowing the sediments to remain in place.



    Proposed  Sec.  264.522(a)(2) would allow the Regional Administrator to

require  that  the  Corrective  Measure  Study  assess  the extent to which

appropriate   source   controls   could  be  implemented,  and  contaminant

concentrations  appropriate  to  the constituent(s) could be reached by the

remedy.  In  some  cases,  bench- or pilot-scale studies may be required to

determine  the  given  treatment technology's performance on the particular

waste  at  the facility. Such studies can often save both time and money in

addressing environmental remediation.



    It will often be appropriate for the Regional Administrator to specify,

prior  to  or  during the course of the CMS, preliminary ''target'' cleanup

levels  for  contaminants  which the permittee should use in evaluating the

items  under Sec. 264.522(a) (1) and (2). These target concentrations would

thus  serve  as  preliminary estimates of the media cleanup standards to be

established  in  the  remedy  selection  process.  Target  levels  might be

specified  to  cover  a  cleanup range (e.g., 10sup -4 level and a 10sup -6

level),  or  a  specific  level  for a constituent that would be EPA's best

estimate  of  the  ultimate  cleanup  standard,  based  on  the information

available at the time.

    There  will be many situations where the levels of cleanup that must be

achieved  will  dictate  the  kinds of cleanup technologies considered, and

thus, the target levels specified in the context of the CMS process will be

a  critical  element  in shaping the study. However, there may also be many

situations  where  it  would not be necessary to specify preliminary target

levels,  such  as  where  the  remedy  involves only removal of a specified

number  of  drums,  or construction of a tank for dewatering sludges. Other

such  situations might be where cleanup concentration levels do not greatly

affect  the  actual design of the remedial technology (e.g., a ground-water

extraction system), or where the owner/operator proposes a remedy that will

effectively  achieve  highly  protective  levels  of  cleanup. In any case,

however,  when  target  levels for a remedy are specified, the Agency would

reserve the right to set cleanup standards different from the target levels

that were identified, since those standards may often be affected by remedy

factors that cannot be fully evaluated until the CMS has been completed.



    Today's proposal would also allow the Regional Administrator to require

an  evaluation  of the timing of the potential remedy (Sec. 264.522(a)(3)),

including  construction  time,  start-up,  and  completion. The timing of a

remedy  will  be  particularly  important  where contamination has migrated

beyond  the  facility  boundary or is nearing potential receptors. In these

cases,  a  prompt remedy would be necessary. In other cases, timing will be

important  in  distinguishing among remedies. Some technologies may require

considerably  less  construction  and  start-up time than others, but would

require  more  time  to  achieve  the cleanup standard. For example, if the

permittee  has a large volume of waste which must be incinerated to achieve

BDAT under the land disposal restriction requirements imposed in HSWA, s/he

may need to build an incinerator and successfully complete the requirements

for  a  trial  burn. If, on the other hand, the wastes to be removed from a

SWMU  are  not  wastes subject to the land disposal restrictions and may be

disposed  in  an  operating  hazardous waste disposal unit at the site, far

less  time  will  be required both to initiate and complete the remedy. The

Agency,  therefore,  may  require  the  permittee to include information on

factors affecting both remedy initiation and completion.



    The  Regional  Administrator  may also require the permittee to include

cost  estimates  for  alternatives  considered  (Sec.  264.522(a)(4)). Cost

information  may  become  a  factor  in  the  remedy selection process when

evaluating  alternative  remedies  which  will achieve an adequate level of

protection.  This  information  will  also serve as a first estimate of the

cost  estimate  required to determine the level of financial assurance that

the permittee must demonstrate when the final remedy is selected.



    Finally,  Sec.  264.522(a)(5)  would provide the Regional Administrator

authority  to  require  the permittee to assess institutional requirements,

such  as  State  or  local  permit  requirements, or other environmental or

public  health  requirements, that may be applicable to the remedy and that

may  substantially  affect  implementation  of  the remedy. State and local

governments   may  have  specific  requirements  related  to  the  remedial

activities  that  could  affect implementation of the remedies evaluated in

the Corrective Measure Study.



    In  addition  to  the  elements listed in proposed Sec. 264.522(a), the

Regional  Administrator  may include other requirements in the scope of the

CMS  as  needed. Such requirements will be specified in the permit schedule

of compliance.



    As  indicated  above, proposed Sec. 264.522(b) would allow the Regional

Administrator  to  specify  one  or  more  potential remedies which must be

evaluated  in  the  CMS.  The  Agency  is  persuaded that this authority is

necessary  to ensure that delays in initiating cleanup will not result from

CMS reports which evaluate only poor or inappropriate remedial solutions.



    Requirements   for   Corrective   Measure  Studies  in  two  particular

circumstances  contemplated under today's proposal merit special attention.

When  either  a phased remedy (see Sec. 264.526(d)) or a conditional remedy

(see  Sec.  264.525(f))  is  contemplated  for  the facility, the scope and

timing  of Corrective Measure Studies may be adjusted to fit the particular

requirements for such remedies.



    Proposed  Sec.  264.526(d) allows the Regional Administrator to specify

(in  the  permit  modification  for  remedy  selection)  that  a  remedy be

implemented  in  phases.  Such  an approach is {pg 30823} anticipated where

separable activities are being addressed at the facility and where, in many

cases,  imposition of further remedial requirements may be dependent on the

experience and/or knowledge gained during preceding phases. In such a case,

the  CMS  may  also  be  divided  into  phases to match the remedial phases

specified in the permit modification.



    Conditional  remedies  are  authorized  under proposed Sec. 264.525(f).

Conditional  remedies  are not final remedies since they do not necessarily

meet all standards for remedies included in Sec. 264.525(a); decisions must

be revisited before the permit can be terminated. If the conditional remedy

is  found  to  meet  all  Sec. 264.525(a) standards, it may be declared the

final   remedy  when  the  decision  is  revisited.  If,  however,  further

corrective action is required to satisfy requirements for a final remedy, a

follow-up CMS may be necessary prior to a final remedy decision.

    4.  Plans  for  Corrective  Measure  Study (Sec. 264.523). This section

would  give  the Regional Administrator authority to require the submission

of  a  plan  for  conducting  the Corrective Measure Study at the time s/he

determines  that a CMS is necessary. Specific requirements for the plan and

a  schedule  for its submission would be included in the permit schedule of

compliance.



    Typically,  a  plan would include a description of the general approach

to  investigating  and  evaluating  potential remedies, a definition of the

overall objectives of the study, a schedule for the study, a description of

the  specific remedies which will be studied, and a description of how each

potential  remedy  will  be  evaluated.  Further,  to  guarantee an orderly

presentation  of  study results, the Regional Administrator may require the

permittee  to  include  as  part  of the plan the format for presenting the

results  of  the  CMS.  Discussions  between the permittee and the Regional

Administrator before the plan is drafted will generally be needed to ensure

that  appropriate  remedial  alternatives  are considered, that appropriate

target  concentration  levels  of  contaminants  are  used,  and  that  the

unnecessary  expenditures  of  time  or other resources for revisions which

otherwise might be required are avoided.



    Upon   receipt   of   the   corrective   measures  plan,  the  Regional

Administrator  will  evaluate  its  adequacy.  If  the  plan  is deficient,

proposed  Sec.  264.523(a) would allow the Regional Administrator to modify

the   plan   or   require   the  owner/operator  to  make  the  appropriate

modifications.   In   some   cases   the  plan  will  require  only  slight

modification,  and  by  actually  making  those  modifications the Regional

Administrator  will be able to eliminate the need for further iterations of

the submission and approval process. In other cases, where a submitted plan

is deficient even after modifications have been made by the owner/operator,

modifying  the  plan will allow the Regional Administrator to cut short the

iterative  process  that  has  not  produced  an  acceptable document. This

provision  of Sec. 264.523(a) is analogous to the authority provided to the

Regional Administrator for modifying interim status closure plans (see Sec.

265.112).  It is also similar to the process involved in obtaining complete

permit applications.



    Upon   approval  of  the  plan  by  the  Regional  Administrator,  Sec.

264.523(b)  would  require  that the permittee conduct the CMS according to

the  approved  plan, including the schedule. Both the plan and the schedule

included in the plan will become an enforceable part of the permit schedule

of compliance.



    5.  Reports  of  Corrective  Measure Study (Sec. 264.524). As proposed,

Sec.  264.524  would  provide  authority  for the Regional Administrator to

require  progress  reports  on  the  Corrective  Measure Study at intervals

appropriate to the site-specific study requirements. Progress reports would

serve  two functions-they would keep the Regional Administrator informed of

the  progress  of  the  study,  and  would provide the basis for a periodic

review  to determine whether midcourse corrections to the study are needed.

For  example,  if a pilot-scale study is conducted for a specific treatment

technology  and  early  results  indicate  that  the  technology  does  not

consistently   achieve   the   expected  concentration  level,  it  may  be

appropriate  to  eliminate  further  study of that particular remedy and to

consider other approaches.



    Today's  proposal  would  require,  in all cases, submission of a final

report  of  the  CMS which summarizes the results of the investigations for

any  remedy  studied,  and  any  pilot  tests  conducted.  The report would

evaluate  each  alternative  in  terms  of  its  anticipated performance in

achieving  the  standards  for  remedies,  which  are  provided  in today's

proposal at Sec. 264.525(a).



    Proposed  Sec.  264.524(c)  would  give  the Agency the authority, upon

review  of the CMS report, to require the permittee to evaluate one or more

additional  remedies  or  to develop in greater detail specific elements of

one  or  more remedies previously studied. This provision would ensure that

appropriate remedies are evaluated by the permittee in sufficient detail to

allow  the Agency to determine its feasibility and effectiveness. In a case

where  the  permittee  does  not  identify an appropriate remedy during the

Corrective  Measure  Study,  the  Agency may require him or her to evaluate

additional  remedies as necessary to ensure that a suitable remedy, meeting

the standards established under Sec. 264.525(a), is developed.



F. Selection of Remedy (Section 264.525)



    1.  General  (Sec. 264.525). Proposed Sec. 264.525 outlines the general

requirements  for selection of remedies for RCRA facilities. As structured,

it  establishes  four  basic  standards  which  all  remedies must meet and

specifies  certain  decision  criteria  which  will be considered by EPA in

selecting  the  most  appropriate  remedy  which  meets those standards for

individual  facilities. In addition, decision factors for setting schedules

for   initiating   and  completing  remedies  are  outlined,  and  specific

requirements   for   establishing   media   cleanup   standards,  including

requirements for achieving compliance with them, are also contained in this

section. The section also specifies requirements for conditional remedies.



    2.  General  Standards  for  Remedies  (Sec. 264.525(a)). Proposed Sec.

264.525(a) specifies that remedies must:



     Be protective of human health and the environment;



     Attain  media  cleanup standards as specified pursuant to Sec. 264.525

(d) and (e);



     Control  the  sources of releases so as to reduce or eliminate, to the

extent practicable, further releases that may pose a threat to human health

and the environment; and



     Comply  with  standards for management of wastes as specified in Secs.

264.550- 264.559.



    These  standards  reflect  the  major technical components of remedies:

cleanup  of  releases,  source  control,  and management of wastes that are

generated  by  remedial  activities. The first standard-protection of human

health  and  the  environment-is  a  general  mandate derived from the RCRA

statute.  This  overarching  standard  requires  remedies  to include those

measures  that are needed to be protective, but are not directly related to

media cleanup, source control, or management of wastes. An example would be

a  requirement  to  provide alternative drinking water supplies in order to

prevent  exposures  to  releases  from  an aquifer used for drinking water.

Another  example would be a requirement for the construction of barriers or

for  other  controls to prevent {pg 30824} harm arising from direct contact

with waste management units.



    Remedies  will  be  required to attain the media cleanup standards that

will  be  specified  by  EPA  according  to  the  requirements  outlined in

subsection  (d)  of  this section. The media cleanup standards for a remedy

will  often  play  a  large role in determining the extent of and technical

approaches  to  the remedy. In some cases, certain technical aspects of the

remedy,  such  as  the practical capabilities of remedial technologies, may

influence  to some degree the media cleanup standards that are established.

It  is because of this interplay between cleanup standards and other remedy

goals and limitations that today's rule establishes media cleanup standards

within the overall remedy selection structure of Sec. 264.525.



    Section  264.525(a)(3)  is  the source control standard for remedies. A

critical  objective  of  remedies  must  be  to  stop further environmental

degradation  by controlling or eliminating further releases that may pose a

threat  to human health and the environment. Unless source control measures

are  taken,  efforts  to  clean up releases may be ineffective or, at best,

will  involve  an essentially perpetual cleanup situation. EPA is persuaded

that effective source control actions are an important part of ensuring the

long-term  effectiveness  and  protectiveness of corrective actions at RCRA

facilities. The proposed source control standard is not intended to mandate

a specific remedy or class of remedies. EPA encourages the examination of a

wide range of remedies. This standard should not be interpreted to preclude

the  equal  consideration of using other protective remedies to control the

source,  such  as  partial  waste  removal,  capping, slurry walls, in-situ

treatment/stabilization and consolidation. Overall, EPA expects this policy

to  be  no  more  stringent  than the threshold criteria used for selecting

remedies under the National Contingency Plan.



    Proposed Sec. 264.525(a)(3) requires that further releases from sources

of   contamination  be  controlled  to  the  ''extent  practicable.''  This

qualifier  is intended to account for the technical limitations that may in

some  cases be encountered in achieving effective source controls. For some

very  large  landfills,  or  large  areas of widespread soil contamination,

engineering  solutions  such  as  treatment  or  capping to prevent further

leaching  may  not  be  technically practicable, or completely effective in

eliminating  further  releases  above health-based contamination levels. In

such  cases,  source  controls may need to be combined with other measures,

such  as  plume management or exposure controls, to ensure an effective and

protective remedy.

    The  proposed  remedy  standard  of  Sec.  264.525(a)(4)  requires that

remedial activities which involve management of wastes must comply with the

requirements   for   solid   waste   management,   as  specified  in  Secs.

264.550-264.559  in today's proposed rule. RCRA remedies will often involve

treatment,  storage  or  disposal of wastes, particularly in the context of

source  control  actions and cleanup of releases. This standard will assure

that management of wastes during remedial activities will be conducted in a

protective manner.



    3.  Remedy  Selection Decision Factors (Sec. 264.525(b)). Proposed Sec.

264.525(b)  specifies  five  general  factors  which shall be considered as

appropriate  by EPA in selecting a remedy that meets the four standards for

remedies,  and  that  represent  an  appropriate  combination  of technical

measures  and management controls for addressing the environmental problems

at  the  facility.  The  five  general  decision  factors  in proposed Sec.

264.525(b) are:



     Long- term reliability and effectiveness;



     Reduction of toxicity, mobility or volume of wastes;



     Short-term effectiveness;

     Implementability; and



     Cost.



    Any  remedy  proposal  developed  under  a Corrective Measure Study and

presented  to  EPA  for final remedy selection must, at a minimum, meet the

four  standards of Sec. 264.525(a). The Agency will then evaluate potential

remedies  against  the  five  decision  factors  listed  in  proposed  Sec.

264.525(b), as appropriate to the specific circumstances of the facility.



    The order of the decision factors listed in proposed Sec. 264.525(b) is

not  intended  to  establish  an  implicit ranking, nor does it suggest the

relative  importance  each  factor might have at any particular facility or

across  facilities  in general. There are circumstances in which any one of

these factors might receive particular weight.



    For  example, long term effectiveness may rule out alternative remedies

that  might  achieve clean up targets in the short term, but at the expense

of  creating  new  or  greater  future  risks that may necessitate a future

corrective action. Conversely, remedies that significantly reduce actual or

imminent   human   exposure  in  the  short  term  may  be  preferred  over

alternatives that eliminate long term risks, but at the cost of lengthening

the   period  during  which  exposure  persists.  Reductions  in  toxicity,

mobility,  or volume are especially valuable in situations where the wastes

or  constituents may degrade into more hazardous or toxic products, or fail

to  naturally  attenuate. Finally, cost may be determinative when more than

one  alternative  remedy  can  reach  the  established  cleanup  target. In

practice,  the  relative  weights  assigned to these five factors will vary

from  facility  to  facility  according  the  site  characteristics. EPA is

soliciting  comment  today  on  situations  in  which  these  tradeoffs may

significantly  affect  the  remedy  in ways which would suggest that a more

prescriptive weighting of the factors might be desirable.



    The  following  is  a general explanation of the five decision factors,

and how they may generally be used in remedy decisions.



    The  Agency  intends to place special emphasis in selecting remedies on

the  ability  of  any  remedial  approach to provide adequate protection of

human  health  and the environment over the long term. Thus, source control

technologies  that  involve  treatment  of wastes, or that otherwise do not

rely  on  containment  structures  or  systems  to  ensure  against  future

releases, will be strongly preferred to those that offer more temporary, or

less  reliable,  controls.  Whenever  practicable,  RCRA  corrective action

remedies  must  be  able  to  ensure  with  a high level of confidence that

environmental damage from the sources of contamination at the facility will

not  occur  in  the  future.  EPA  believes  that  long-term reliability of

remedies  is  an  essential  element in ensuring that actions under section

3004(u) satisfy the fundamental mandate of RCRA to protect human health and

the environment.



    The  second  decision  factor-reduction of toxicity, mobility or volume

-is  directly  related to the concept of long-term reliability of remedies.

As  a general goal, remedies will be preferred that employ techniques, such

as  treatment  technologies,  that  are capable of permanently reducing the

overall  degree  of  risk  posed  by  the  wastes  and  constituents at the

facility.  Reduction  of  toxicity,  mobility  or volume is thus a means of

achieving  the  broader objective of long-term reliability. EPA recognizes,

however,  that  for  some  situations,  achieving substantial reductions in

toxicity,  mobility  or  volume  may  not be practicable or even desirable.

Examples  might  include large, municipal-type landfills, or wastes such as

unexploded  munitions  that  would  be  {pg  30825}  extremely dangerous to

handle,  and for which the short-term risks of treatment outweigh potential

long-term benefits.



    The  third decision factor-short term effectiveness-may be particularly

relevant  when  remedial  activities will be conducted in densely populated

areas,  or  where  waste characteristics are such that risks to workers are

high,  and  special  protective  measures are needed. Implementability, the

fourth  decision  factor,  will  often be a determining variable in shaping

remedies.  Some  technologies  will require State or local permits prior to

construction, which may increase the time needed to implement the remedy.



    One  of  the  decision  factors  which  raises particular issues in the

context  of  RCRA  remedies  is  that of cost. RCRA's overriding mandate is

protection  of human health and the environment. However, EPA believes that

relative  cost  is  a relevant and appropriate consideration when selecting

among alternative remedies that achieve the clean up range.



    EPA's  experience  in  Superfund  has  shown that in many cases several

different  technical  alternatives  to  remediation  will  offer equivalent

protection  of  human  health  and  the environment, but may vary widely in

cost.  The  Agency  believes  that it is appropriate in these situations to

allow  cost  to  be one of the several factors influencing the decision for

selecting among such alternatives.



    The  exact emphasis placed on these decision factors, and how they will

be balanced by EPA in selecting the most appropriate remedy for a facility,

will  necessarily  depend  on the types of risks posed by the facility, and

the  professional  judgment  of the decisionmakers. Comment is specifically

invited  on the remedy selection approach outlined in today's proposed rule

and preamble.



    4.  Schedule  for  Remedy  (Sec.  264.525(c)). Proposed Sec. 264.525(c)

would  require  the  Regional  Administrator  to  specify  a  schedule  for

initiating and completing remedial activities as a part of the selection of

remedy  process.  Some  of the factors that will be considered when setting

the  schedule  are  enumerated  in  proposed Sec. 264.525(c) (1)-(5). These

factors include:



     Extent and nature of contamination at the facility;



     Practical  capabilities  of  remedial technologies as assessed against

cleanup standards and other remedial objectives;



     Availability  of  treatment  or  disposal  capacity  for  wastes to be

managed as part of the remedy;



     Desirability   of  utilizing  emerging  technologies  not  yet  widely

available  which  may offer significant advantages over currently available

technologies; and

     Potential  risks  to human health and the environment from exposure to

contamination prior to remedy completion.



    Proposed  Sec.  264.525(c)(6)  would  allow  the Regional Administrator

flexibility  to  consider  other relevant factors in setting a schedule for

remedy initiation and completion. Such factors could relate to the remedial

technology to be employed or the characteristics of the particular waste or

facility being addressed.



    The  timing  of remedy implementation and completion will be determined

after these and other factors are considered by the Regional Administrator,

and  a  schedule of compliance will be included in the modified permit. The

Agency  wishes  to  emphasize,  however,  that  expeditious  initiation  of

remedies and rapid restoration of contaminated media is a high priority and

a  major  goal of the RCRA corrective action program. The schedule included

in   the   permit   will  be  an  enforceable  permit  condition,  and  the

owner/operator  will  be  obligated  to seek any change in the schedule for

remedy  implementation and completion prior to milestones established. This

approach  is  consistent  with  the  Agency's  application  of schedules of

compliance  to  other  aspects  of  the  corrective action program proposed

today.

    EPA  expects  that  many  different specific factors will influence the

timing  of remedies. For example, the level of technical expertise required

and  available  to  implement  a particular remedial technology could be an

important  factor,  or the amount and complexity of construction which must

precede  actual  cleanup,  or  the  amount of time which would routinely be

needed  to  achieve  the  media  cleanup standards set in remedy selection,

given  a specified technology. All major variables which will affect remedy

timing  are  expected  to  be  assessed  routinely  in the CMS, and will be

considered  by  EPA  in  setting  aggressive  yet  realistic  schedules for

remedial activities.



    While   the   Agency's  strong  preference  is  for  rapid  and  active

restoration  of  contaminated  media,  it  is  recognized that there may be

limited  cases  where  a  less  aggressive schedule may be appropriate. For

example, in situations where ground-water cleanup standards can be achieved

through  natural  attenuation  within a reasonable timeframe, and where the

likelihood  of  exposure  and  potential  risks  to  human  health  and the

environment  from  exposure  to  contaminated  ground  water  prior  to the

attainment  of  cleanup  standards  is  minimal, a remedy schedule based on

natural attenuation could be determined to be the most appropriate solution

for  a  site.  Thus, such factors as location, proximity to population, and

likelihood  for exposure may allow more extended timeframes for remediating

ground waters.



    Management strategies adopted in the remedy selection decision also may

affect  the  timing  of  remedies.  For  example,  proposed Sec. 264.526(d)

(discussed  later  in this preamble) would allow the Regional Administrator

to  require  implementation  of  remedies in discrete phases or incremental

segments.  Such  a  phased approach often will affect overall timing of the

final  cleanup  for  the  facility.  As  one or more phases of the required

remedy  are  completed, the Regional Administrator may choose to review the

results  achieved  by  that phase prior to requiring subsequent stages. For

example,  if  results  of an initial treatment process for wastes in a SWMU

are  successful,  the  next  phase of the remedy might apply that treatment

technology  to  the  remainder  of  the  wastes at the facility. Similarly,

timing  of remedies often may be influenced by the need to address the most

important  environmental  problems  first.  This  might  be  the case where

ground-water  contamination  has migrated beyond the facility boundary; the

initial  remedial step would be to require installation of a pump and treat

system  to  stop  further migration. (This could also be done as an interim

measure  prior  to  final  remedy  selection; see Sec. 264.540.) Subsequent

actions  to  perform source control, or other remedial action might then be

phased  in  as dictated by their environmental priority, practicability, or

other factors.

    In  addition  to  these  kinds of considerations, adequate time must be

allowed   in   the  schedule  of  the  remedy  for  the  owner/operator  to

decontaminate  and  remove, close, or dispose of units, equipment, devices,

or  structures  used  to  implement  the remedy. The time needed to perform

specific  activities  associated  with this requirement necessarily will be

evaluated on a site-specific basis.



    5.  Media  Cleanup  Standards  (Sec.  264.525(d))-  a. General. Section

264.525(d)(1)(i)-(iv)   outlines   the   Agency's   proposed  approach  for

establishing  media  cleanup  standards  (MCS) through the remedy selection

process.



    Media  cleanup standards represent constituent concentrations in ground

{pg  30826} water, surface water, soils, and air that remedies must achieve

to  comply  with  standards  for  remedies  under Sec. 264.525(a)(2). Media

cleanup  standards are established at concentrations that ensure protection

of human health and the environment, and are set for each medium during the

remedy selection process.



    The  Agency  is  proposing  to  set  media cleanup standards within the

overall  context of the remedy selection process. As part of the Corrective

Measure  Study  development  process, the Agency will typically provide the

owner/operator   with  target  cleanup  levels  for  significant  hazardous

constituents in each medium of concern when he/she is required to perform a

CMS.  For  carcinogens,  these  targets  will  be  established  within  the

protective  risk  range of 1X10sup -4 to 1X10sup -6, based on site-specific

factors,  unless another level is deemed necessary to protect environmental

receptors. EPA may start the analyses by establishing target cleanup levels

at  the  action  level,  understanding  that  action  levels  are set under

conservative  assumptions  and  that  the cleanup levels may be modified as

appropriate. The remedies analyzed by the owner/operator would generally be

designed  to meet these targets. After reviewing the permittee's Corrective

Measure  Study  (CMS)  using  the  remedy  selection  factors given in Sec.

264.525(b), the Agency will select a remedy and set media cleanup standards

that must be achieved.



    The  Regional  Administrator  will specify media cleanup standards that

the  remedy  must  achieve,  as  necessary  to protect human health and the

environment.  The  Regional  Administrator may set a media cleanup standard

for  each  constituent for which an action level has been exceeded, as well

as other hazardous constituents which the Regional Administrator determines

to  pose  a  threat to human health and the environment (e.g., constituents

considered    under   Sec.   264.520(b)).   Alternatively,   the   Regional

Administrator may specify media cleanup standards for a subset of hazardous

constituents  present  at  the  site  which  are  the  most  toxic, mobile,

persistent  and  difficult  to remediate, considering the concentrations at

which  they  are present at the site. This approach may be most appropriate

where  there  are  large  numbers  of  hazardous  constituents present in a

medium.  The  Regional  Administrator may determine in the remedy selection

process  that  some  cause  exists  for  not setting a standard for certain

constituents,  as  discussed later in this section of the preamble. Section

264.525(d)(1) describes the specific approach the Agency proposes to follow

in setting these levels.



    b.  Protectiveness.  A  primary goal of corrective action is to achieve

cleanup consistent with existing media-specific cleanup standards, or, when

such  standards  do not exist, to achieve protection against risks to human

health  such  that the excess lifetime risk from exposure to a carcinogenic

hazardous  constituent in soil, air, ground water or surface water does not

exceed  10sup  -6.  A variety of practical constraints, as described later,

can  prevent the consistent achievement of that goal. However, the risks to

an  individual  from  exposure  to  a hazardous constituent in contaminated

media should not exceed approximately 10sup -4.



    In the corrective action program, remediation decisions must be made at

hundreds  of  diverse  sites  across the country. Therefore, as a practical

matter,  the  human health goal will typically be established by means of a

two-step  approach. First, EPA intends to use a lifetime excess cancer risk

of  10sup -6 as a point of departure for establishing remediation goals for

the  risks  from  hazardous  constituents  at specific sites. This starting

point  is  generally  consistent  with historical Agency practice. While it

expresses  EPA's  preference, it is not a strict presumption that the final

cleanup will attain that risk level.



    The second step involves consideration of a variety of site-specific or

remedy  specific factors. Such factors will enter into the determination of

where  within  the  risk  range  of  10sup -4 to 10sup -6 the media cleanup

standard for a given hazardous constituent will be established.



    This  means that a risk level of 10sup -6 is used as the starting point

for determining the most appropriate risk level that alternatives should be

designed  to  attain.  The  use  of 10sup -6 expresses EPA's preference for

remedial  actions  that  result  in risks at the more protective end of the

risk  range,  but this does not reflect a presumption that the final remedy

should  attain  such  a  risk level. The ultimate decision of what level of

protection will be appropriate depends on the selected remedy, which is, in

turn,  based on the criteria listed in proposed Sec. 264.525(b). Because of

factors  related  to  exposure, uncertainty, and technical limitations, EPA

expects  that  the  entire  risk  range  will  be available and utilized at

various sites.



    In the Agency's view, it is important to have an initial value to which

adjustments  can  be  made,  particularly  since  the risk range covers two

orders  of  magnitude.  By  using  10sup  -6 as the point of departure, EPA

intends  that  there  be  a preference for setting remediation goals at the

more  protective  end  of the range, other things being equal. EPA does not

believe  that  this preference will be so strong as to preclude appropriate

site- specific factors.



    Several examples illustrate how under today's proposal EPA might adjust

cleanup  standards  in light of potential uses. First, ground water that is

not a potential source of drinking water would not require remediation to a

10sup  -4  to  10sup  -6  level  (although cleanup to address environmental

concerns  or  to  allow  other  beneficial uses might be required). Second,

ground  water  in a broadly contaminated area would typically be remediated

to  specific  background  levels  as  described  below,  except  where  the

remediation   took   place  as  part  of  an  area-wide  cleanup.  Finally,

contaminated  soil  at  an  industrial  site  might  be  cleaned  up  to be

sufficiently protective for industrial use but not residential use, as long

as there is reasonable certainty that the site would remain industrial.

    At  the  same  time,  in exceptional circumstances, other site-specific

exposure  factors  may  indicate  the  need  to establish a risk goal for a

particular  contaminant  that  is  more protective than the overall goal of

10sup  -6. These site-specific exposure factors may include: The cumulative

effect  of  multiple contaminants (see following discussion); the potential

for  human  exposure  from  other  pathways  at  the  facility;  population

sensitivities;   potential   impacts   on   environmental   receptors;  and

cross-media impacts.



    In  summary,  EPA  has proposed an approach that allows a pragmatic and

flexible  evaluation of potential remedies at a site while still protecting

human health and the environment. This approach emphasizes the overall goal

of  10sup  -6  as the point of departure (in situations where there are not

existing  standards,  such as MCLs), while allowing site or remedy-specific

factors,  including  reasonably  foreseeable future uses, to enter into the

evaluation  of what is appropriate at a given site. As risks increase above

10sup  - 6, they become less desirable, and the risks to individuals should

not exceed approximately 10sup -4.



    Proposed Sec. 264.525(d)(1)(iii) lists four considerations which may be

used in establishing media cleanup standards. These considerations apply to

setting  standards  for  both  carcinogens and non-carcinogens. The factors

listed  above which may be used in determining {pg 30827} cleanup standards

for  carcinogens  within the risk range are intended to be included broadly

within these four general considerations.



    (1)   Multiple   Contaminants.   The  first  consideration  under  Sec.

264.525(d)(1)(iii)(A)  is  multiple contaminants in the medium. In order to

ensure  that  individuals  exposed  to  a medium (e.g., via drinking ground

water) will be protected it may be necessary to consider the risks posed by

other  constituents  in  that  medium before a media cleanup standard for a

single  constituent  can  be established. In considering the risks posed by

multiple contaminants, the Agency will follow the procedures and principles

established  in its ''Guidelines for the Health Risk Assessment of Chemical

Mixtures''   (51   FR   34014).  The  cumulative  risk  posed  by  multiple

contaminants  should not exceed a 1X10sup -4 cancer risk. All other factors

being  the  same, the media cleanup standard for a constituent present in a

medium that is contaminated with many other constituents posing significant

risks  may be established at a lower concentration than if that constituent

were the sole contaminant in the medium.



    (2)  Environmental  Receptors.  Remedies  must  be  protective  for the

environment  as  well as human health. Section 264.525(d)(1)(iii)(B) allows

the Regional Administrator to consider actual or potential exposure threats

to   sensitive   environmental  receptors  in  establishing  media  cleanup

standards.  Standards,  criteria,  and  other health-based levels are often

based  on  protection  of  human  health, since more information is usually

available on effects of contaminants on humans (or laboratory animals) than

on  environmental receptors. Levels set for protection of human health will

frequently  also  be  protective  of the environment. However, there may be

instances  where adverse environmental effects may occur at or below levels

that  are protective of human health. Sensitive ecosystems (e.g., wetlands)

or  threatened  or  endangered  species or habitats that may be affected by

releases  of  hazardous  waste  or  constituents  should  be  considered in

establishing  media cleanup standards. The Agency plans to develop guidance

on  evaluating  ecological  impacts.  Until  more  substantial  guidance is

developed,  the  Agency  intends to determine on a case-by- case basis when

standards  must be established at lower concentrations to protect sensitive

ecosystems  or  environmental  receptors.  For  releases  to surface water,

Federal  Water  Quality  Criteria  may  be  used as guidance in making this

determination.



    (3)  Other  Exposures.  Generally,  the  Agency  will only consider the

contamination  contributed  by the releases subject to corrective action in

setting  protective  cleanup levels. In unusual situations, however, it may

be  necessary  to  consider  the  presence  of other exposures or potential

exposures  at  the  site  (Sec.  264.525(d)(1)(iii)(C)).  For  example,  if

residents  living  in  close proximity to a facility receive unusually high

exposures  to  lead due to the presence of a lead smelter in their town, it

may  be necessary to set lower cleanup levels for lead in ground water from

a  SWMU  than  would  otherwise  be  necessary.  Remedies  whose cumulative

exposures  (i.e.,  mixtures of chemicals, or multiple pathways of exposure)

fall  within  the risk range for carcinogens (1X10sup -4 to 1X10sup -6), or

meet  acceptable  levels  for non-carcinogens, are considered protective of

human health.



    Chronic  exposure  to  multiple  SWMU-contaminated  media, although not

likely   at   most   sites,   may   be   considered   under  proposed  Sec.

264.525(d)(1)(iii)(C)  in  establishing media cleanup standards. An example

might  be  where  releases from solid waste management units are present in

both  ground  water  and  soils  (from  wind  blown particulates) at nearby

residences.  In this case, it might be appropriate to set cleanup standards

for  either  or  both  releases at more conservative levels, to account for

such  cumulative  risk  concerns.  The Agency will examine such cross-media

effects, when appropriate, on a case-by-case basis.



    (4)  Remedy- Specific Factors. Section 264.525(d)(1)(iii)(D) allows the

Regional   Administrator   to   consider  the  reliability,  effectiveness,

practicability,  and  other  relevant factors of the remedy in establishing

media  cleanup standards. These factors are related to the remedy selection

decision  factors  specified  in  Sec.  264.525(b). An example of how these

factors  may  be  considered  by  the  Agency in establishing media cleanup

standards under Sec. 264.525(d) is the following. Suppose that one remedial

alternative  can theoretically treat constituents in soil to concentrations

posing  a  1X10sup  -6  risk level, but relies on a technology that has not

been  successfully  demonstrated under conditions analogous to those at the

site  in  question,  or  may  be  unreliable  for  other  reasons.  In this

situation,  consideration of the long-term reliability and effectiveness of

the  remedy  may  result  in  the  selection of another technology that can

achieve  a  1X10sup  -5  risk  level,  but has been demonstrated to be more

reliable.



    A variety of exposure-related factors may be considered in establishing

media  cleanup  standards.  For  example,  the  potential  and pathways for

exposure  to  soils  may vary greatly across sites. Media cleanup standards

will  generally be established for soils to protect individuals from health

threats  resulting  from  direct  contact to soils. In some cases, however,

individual  health  may be threatened due to the absorption of contaminants

in  soils  by  plants  and  in  turn  by  grazing  animals  used  for human

consumption. In these cases, cleanup standards might be set on the basis of

protecting health from this exposure pathway.



    In  establishing media cleanup standards for soil based on exposure via

direct  contact,  the  Agency  may  use  the exposure assumptions listed in

Appendix  D. These exposure assumptions are based on a daily intake of soil

through  ingestion,  of particular concern for young children (see preamble

section  VI.E.2.f  for a detailed discussion of soil exposure assumptions).

However,  the  Agency  recognizes  that these exposure assumptions would be

appropriate   only  where  soil  ingestion  is  plausible.  The  Agency  is

considering  using  different exposure assumptions where different exposure

scenarios are likely based on current and projected future land use at/near

the  site.  For  example,  for  sites  located in industrial areas that are

likely to remain industrial in the foreseeable future, exposure assumptions

more  appropriate  to industrial land use might be used. Thus, the exposure

assumptions proposed in Appendix D would apply to sites near areas that are

now residential or are reasonably projected to become residential. However,

the   Agency  recognizes  that  considerable  uncertainty  is  involved  in

forecasting  future  land  use.  The Agency requests comment on the general

concept  of using current and projected land use to develop likely exposure

scenarios for different sites in developing media cleanup standards, and on

specific  exposure  assumptions  which  are  reasonable for these different

exposure scenarios.

    It  should  be  understood that the Agency does not intend typically to

establish  cleanup standards per se (i.e., according to Sec. 264.525(d)(1))

for  ''deep'' soils that do not pose a direct contact exposure threat. Such

contaminated soils can, however, often be a transfer source of contaminants

to  other  media,  such  as through leaching of wastes into ground water or

surface  water.  In  such  {pg 30828} cases the contaminated soils would be

dealt with as a source, rather than as a release; that is, the remedy would

specify  containment,  removal  or  treatment measures for the soils in the

same  manner  as  for  other  sources  of  releases (e.g., landfills). Such

measures  would  be  required  as  necessary  to  ensure that media cleanup

standards for the affected media are not exceeded.



    There  are  several means of investigating the mobility of contaminants

in   soil,   including   a  descriptive  approach  (i.e,  consideration  of

constituent  and soil properties), and/or the use of mathematical models or

leaching  tests  (for  mobility  to  ground  water).  The Agency is further

evaluating the use of different leach tests, and requests comments on these

and other ways of estimating media transfer of soil contaminants.



    The  Agency  recognizes that there are also technical limitations which

must be considered, in addition to scientific information about the hazards

to  human  health  and  the  environment,  in  establishing  media  cleanup

standards. For example, media cleanup standards would not be set lower than

detectable    levels.    Consideration   of   reliability,   effectiveness,

practicability,  and  other  factors  will  generally  be  considered  on a

case-by-case basis.



    c.  Cleanup  Levels  and Other Sources of Contamination. In some cases,

solid  waste  management  units  will be located in areas contaminated from

other  sources.  For example, a solid waste management unit may lie over an

aquifer already contaminated from off-site sources or from other activities

at  the  facility.  Similarly,  an area of contaminated soil resulting from

waste  management  may  lie  in  a broader area of high naturally occurring

contamination.  In  such cases, section 3004(u) gives EPA authority only to

require  cleanup  of  contaminants  released  from  on-  site  solid  waste

management  units.  This  authority  does not extend to cleanup of releases

from  production areas (unless the releases are ''routine and systematic'')

or  from  off-site  sources  (unless  those  sources  are  also  at  a RCRA

facility).



    Proposed  Sec.  264.525(d)(1)(v)  codifies  this  limitation on section

3004(u)  authority  by  allowing the facility owner/operator to demonstrate

that  a  specific concentration of a constituent in the vicinity of a solid

waste  management  unit  does  not  come  from  that  unit,  but  rather is

attributable to sources other than on-site solid waste management units. If

the  owner/operator can successfully make this demonstration, EPA would not

have   the  authority  under  subpart  S  to  require  cleanup  below  that

concentration.  Proposed  Sec. 264.525(d)(1)(v) provides, however, that the

Regional  Administrator  may  determine  that  cleanup  to levels below the

background concentration is necessary for the protection of human health or

the environment in connection with an area-wide cleanup under RCRA or other

authorities.



    The  best  example  of  this  limitation on section 3004(u) is found in

contaminated  ground  water.  If  a specific constituent is found in ground

water  downgradient  of  a  solid waste management unit at levels exceeding

action levels, a CMS would ordinarily be required. However, if the facility

owner/operator  can  demonstrate that the constituent levels did not exceed

upgradient ''background'' levels, and that the upgradient background levels

did  not  come  from  other  solid  waste management units on the facility,

cleanup  would  not  be  required.  Similarly,  even  if  the  downgradient

concentration  exceeded  upgradient  background,  cleanup could be required

only  to  the upgradient background levels. This approach to ''background''

is the same as the one found in subpart F.



    In  the  case  of  soil,  the  same  principle applies. Section 3004(u)

provides  EPA  the  authority  only  to require owner/operators to clean up

contaminated  soils  to  the  extent  that  the  contamination derives from

releases  from  a solid waste management unit (or that the area itself is a

solid  waste  management  unit).  Therefore,  cleanup of soils would not be

required  under  subpart S below ''background'' levels. The best measure of

background  levels for soils will generally be naturally occurring soils in

areas  not  contaminated  by  a facility's activities-for example, off-site

soils. However, in areas broadly contaminated with constituents not subject

to  section  3004(u)  (for  example,  from  manufacturing  or  off-site air

emissions),  an  owner/operator  may  be  able  to  argue successfully that

constituents found on a facility below a certain level cannot be attributed

to releases from a solid waste management unit.



    Today's  proposal,  however,  does not allow RCRA facilities located in

contaminated  areas  to ignore facility contributions to the contamination.

The  permittee  will  be  required  to clean up the contamination caused by

his/her  waste  management activities, unless a determination is made under

proposed  section  264.525(d)(2)  that  remediation  of  the release is not

required.



    In  reviewing  the  demonstration  under  Sec.  264.525(d)(1)(v) that a

hazardous  constituent(s)  at  a  specific  concentration  in  a  medium is

naturally occurring or is from a source other than a solid waste management

unit  at  the  facility, the Regional Administrator would evaluate sampling

data  developed  by  the permittee. The Regional Administrator would assess

the  accuracy of these data and evaluate the statistical procedures used by

the   permittee   to   characterize   these  concentrations.  The  Regional

Administrator  may  use  the  performance  standards proposed on August 24,

1987, at 40 CFR 264.97 to make this assessment (52 FR 31948).



    6.  Determination  that  Remediation  of  Release  to  a  Media Cleanup

Standard  Is  Not  Required.  Proposed  Sec. 264.525(d)(2) identifies three

situations  in  which  the Regional Administrator may decide not to require

cleanup  of  a  release of hazardous waste or hazardous constituents from a

SWMU   to   a  media  cleanup  standard  meeting  the  conditions  of  Sec.

264.525(d)(1).  These  situations  are  limited  to cases where there is no

threat  of  exposure to releases from SWMUs; cases where cleanup to a level

meeting  the  standards  of  Sec.  264.525(d)(1)  will  not  result  in any

significant  reduction  in  risk  to  humans  or  the  environment;  or  is

technically  impracticable.  In situations where the Regional Administrator

determines  that  cleanup  to  a  level  meeting  the  conditions  of  Sec.

264.525(d)(1)  is  technically  impracticable,  the  owner/operator  may be

required to remediate to levels which are technically practicable and which

significantly reduce threats to human health and the environment.

    The  Agency  does not believe that continued further degradation of the

environment  should  be  allowed,  even  in  those  situations where actual

cleanup of releases may not be required. As provided by Sec. 264.525(d)(3),

the  Regional  Administrator may require source control measures to control

further releases into the environment, or other measures to protect against

exposure to contaminated media. If source control or other measures are not

necessary  (e  g.,  the  source  no  longer  exists), a determination of no

further action may be made pursuant to Sec. 264.514.



    a.  Areas  of  Broad  Contamination.  In  some  cases,  SWMUs releasing

hazardous  constituents  to  the  environment will be located in areas that

already  are significantly contaminated. Where the risks from releases from

the  SWMUs  are  trivial  compared to the risk already present from overall

area-wide contamination, or where remedial measures aimed at the SWMU would

not  significantly  reduce  risk, EPA believes that remediation of releases

from   the   SWMU  to  a  cleanup  level  meeting  the  standards  of  Sec.

264.525(d)(1)  would  not  be {pg 30829} necessary or appropriate. In these

situations,   proposed  Sec.  264.525(d)(2)(i)  would  allow  the  facility

owner/operator   to   provide   the   Regional   Administrator  information

demonstrating  that such remediation would provide no significant reduction

in  risk.  If the demonstration were successful, the Regional Administrator

would  determine  that remediation to a level meeting the standards of Sec.

264.525(d)(1) was not necessary.



    For  example,  ground  water  below  a  leaking  SWMU  might be heavily

contaminated  from  off-site  sources.  In this case, removal of the SWMU's

contribution   to  the  contamination  might  have  very  limited  benefit,

particularly  if  that contribution was relatively minor. Similarly, a SWMU

such  as  a  surface  impoundment  might be contributing relatively trivial

amounts  to  area-wide  air problems. Control of the SWMU releases might do

very  little,  in such cases, to improve the overall situation in the area,

yet (in the case of an operating unit) could be extremely burdensome to the

owner/operator.



    In  such  cases,  EPA  believes  that it will make more sense to attack

area-wide  problems,  where they are determined to threaten human health or

the  environment, on a more comprehensive basis and to focus on the primary

sources  of release- for example, under RCRA section 7003, CERCLA, or other

environmental  authorities. The Agency does not believe that it makes sense

routinely to require remediation of SWMU releases where they represent only

a trivial contribution to an area's problems.



    Two  points  should  be  stressed  here,  however.  First, the facility

owner/operator  would  be required to take corrective action where it could

have  a  significant  effect  on  reducing risks-for example, as part of an

area-wide  cleanup  strategy. The fact of area-wide contamination would not

eliminate  EPA's  authority  to  require  action in this case. It should be

noted  that  an  area-wide  cleanup might not be coordinated under a single

authority,  or  within  a  specific  narrow time frame; rather the Regional

Administrator  may  use  a  variety  of authorities to address an area-wide

contamination  problem  over  time.  Second, EPA in any case would have the

authority  under  proposed  Sec. 264.525(d)(3) to require source control to

prevent  further  releases,  or  to  require  other  measures such as those

necessary to protect against exposure to the affected medium.



    The  Agency  has  not attempted to define ''significant reductions'' in

risk  in  this  rulemaking,  and  believes  the  decision is best made on a

case-by-case  basis.  However,  the  Agency seeks comment on whether a more

specific definition is necessary for the purposes of this rulemaking.



    b.  Ground  Water.  Under proposed Sec. 264.525(d)(2)(ii), the Regional

Administrator  may  determine  that  remediation of a hazardous constituent

released  from a SWMU into ground water to a media cleanup standard meeting

the  standards  of  Sec.  264.525(d)(1)  is  not necessary to protect human

health  and  the  environment  if: (1) The ground water is not a current or

potential  source  of  drinking  water;  and  (2)  the  ground water is not

hydraulically  connected  with  waters  to which the hazardous constituents

could  migrate  in concentrations which could increase contamination in the

water to concentrations that exceed action levels.



    In interpreting whether the aquifer is a current or potential source of

drinking  water, the Agency will generally use the approach outlined in the

Agency's  Ground-Water Protection Strategy (August 1984 and as subsequently

modified)  as guidance. Generally, Class III aquifers will be considered to

meet  the  requirements  specified  in  Sec.  264.525(d)(2)(ii).  Class III

aquifers  are  ground  waters  not considered potential sources of drinking

water  and  are considered to be of limited beneficial use. They are ground

waters  that  are  heavily saline, with total dissolved solids (TDS) levels

over  10,000  mg/l,  or are otherwise contaminated beyond levels that allow

cleanup using methods reasonably employed in public water system treatment.

These ground waters also must not migrate to Class I or II ground waters or

have a discharge to surface water that could cause degradation.



    A  determination  under  Sec.  264.525(d)(2)(ii)  that remediation to a

media cleanup standard is not necessary might be made in situations where a

SWMU  located in a heavily industrialized area has released to ground water

in  an  aquifer  that  is  surrounded by ground water that has been heavily

contaminated  from  non-SWMU sources. It is not the intention of the Agency

to  create  a ground-water ''island of purity'' that is unlikely to be used

for drinking water or other (non-industrial) beneficial purposes due to its

location in an area historically used only for industrial purposes.



    Information from the State and/or local government as to the beneficial

use  of  the  ground  water may also be useful if the ground water has been

classified for specific uses. If the ground water is not a potential source

of  drinking water but has other beneficial uses (e.g., agricultural), then

remediation  to  a  media  cleanup  standard  may not be required; however,

remediation of the ground water to its beneficial use would be required, as

provided under Sec. 264.525(d)(3).



    If  a  determination  under  Sec.  264.525(d)(2)(ii)  is made where the

ground  water  poses a threat to environmental receptors, or poses a threat

to  human  health  through  an  unusual  exposure pathway (e.g., ponding or

basement  seepage from shallow aquifers), remediation to alternative levels

could  likewise  be  required  pursuant  to  Sec. 264.525(d)(3). The Agency

believes  that  health-based  concerns  may  be  secondary to environmental

concerns  for  releases  to  Class III ground waters. The need to remediate

Class  III  ground  waters will be assessed on a case-by-case basis. In any

case,  cleanup  levels  for  ground water that is not a potential source of

drinking water would be established at other than ''drinkable'' levels.

    In  other cases, ground water may not fall into Class III, but, because

of its distance from any population or other factors, is unlikely to become

a  source  of  drinking  water  in  the foreseeable future. In these cases,

remediation  might  be  carried  out  over  an extended period of time, and

natural  attentuation  might  play a major role in the remedy. The issue of

timing  of  remedies  is discussed in more detail in section VI.F.4 of this

preamble.



    To demonstrate whether the ground water is hydraulically connected with

waters  to which the hazardous constituents are migrating, samples of water

should be taken within the discharge zone of the ground-water contamination

plume.  The  discharge  zone will have to be determined on a site- specific

basis, and is dependent on the local hydrogeology. If, upon sampling in the

discharge   zone,  the  levels  of  the  constituent  of  concern  are  not

detectable,  a  statistical comparison of sampling data does not need to be

performed.  However, if the discharge levels are detectable, an appropriate

statistical   procedure   should   be   used  to  compare  the  constituent

concentration  in  the  discharge  zone  to  the  constituent concentration

upstream.  Guidance  on  appropriate statistical techniques may be obtained

from  the  proposal  on  statistical  methods for use in the RCRA subpart F

program dated August 24, 1987 (proposed as 40 CFR 264.97; see 52 FR 31948).

In  addition, the Agency expects to develop further guidance on appropriate

statistical techniques for making these determinations. {pg 30830}



    The   determination  of  whether  the  ground  water  is  hydraulically

connected  with  waters  to  which the hazardous constituents are likely to

migrate  in  concentrations  which  exceed  action levels will be made on a

site-specific  basis.  The  physical  and  chemical  characteristics of the

hazardous constituents in ground water, the concentrations of the hazardous

constituents  in  ground water and surface water, and local hydrogeological

characteristics should be considered in making this determination.



    c.  Technical  Impracticability. Proposed Sec. 264.525(d)(2)(iii) would

allow  the  Regional Administrator to make a determination that remediation

of  a  release  to  a  media  cleanup standard meeting the criteria of Sec.

264.525(d)(1)   is   not   required   when   remediation   is   technically

impracticable.  The  determination of technical impracticability involves a

consideration  of  both  engineering  feasibility  and  reliability. Such a

determination  may  be made, for example, in some cases where the nature of

the  waste  and the hydrogeologic setting would either prevent installation

of  a  ground-water  pump  and  treat  system  (or  other effective cleanup

technology),  or  limit  the  effectiveness  of  such a system-e.g., dense,

immiscible  contaminants  in mature Karst formations or in highly fractured

bedrock.  In other situations a determination under Sec. 264.525(d)(2)(iii)

may  be made when remediation may be technically possible, but the scale of

operations  required  might  be of such a magnitude and complexity that the

alternative  would  be impracticable. The Agency is persuaded that in these

and  other  situations  determined  to  be technically impracticable from a

remedial  perspective  the Regional Administrator should have the authority

to not require remediation to media cleanup standards.



    Decisions  regarding  the technical impracticability of achieving media

cleanup  standards  must  be  made upon careful evaluation of the technical

circumstances  involved.  Facility  owner/operators  will  be  required  to

provide clear and convincing information to support any assertion that such

cleanup is technically impracticable.



    As  suggested  in the examples provided above, the Agency believes that

the  concept  of technical impracticability may in some cases also apply to

situations  in  which  use  of available remedial technologies would create

unacceptable  risks to workers or surrounding populations, or where cleanup

would  create  unacceptable  cross-media  impacts. For example, some wastes

present  a  high  potential  for  explosion  during  excavation. The Agency

expects  that these types of situations which could lead to a determination

of   technical  impracticability  will  be  quite  rare.  In  the  case  of

cross-media  impacts,  it is expected that sound techniques and engineering

controls-or other remedial alternatives- should be available to effectively

minimize such cross-media transfer effects. In the absence of such controls

or   alternatives,   however,  remediation  of  such  situations  could  be

determined technically impracticable. The Agency is specifically soliciting

comment   today   on   the  types  of  situations  which  might  warrant  a

determination  that  remediation  of  a release to a media cleanup standard

meeting  the  standard  of Sec. 264.525(d)(1) is technically impracticable,

and would not, therefore, be required.



    7.  Demonstration  of  Compliance  With  Media  Cleanup Standards (Sec.

264.525(e)).  Section 264.525(e) outlines the Agency's proposed approach to

establishing   conditions   the  permittee  must  fulfill  to  achieve  and

demonstrate  compliance  with  the  media cleanup standards (or alternative

cleanup  levels)  established  during  the  remedy selection process. Media

cleanup   standards   are   contaminant   concentration  limits  set  on  a

constituent-specific  basis  in  each  environmental  medium  in  which the

permittee   is   required  to  remediate  a  release.  (See  proposed  Sec.

264.525(d).) The site-specific conditions which would be established by the

Regional   Administrator  in  the  permit  under  Sec.  264.525(e)  include

compliance  points  (where  cleanup  standards  must  be achieved) for each

medium;  sampling,  analytical,  and statistical methods the owner/operator

must  use  in  compliance demonstrations; and the length of time over which

the  data must show that the media cleanup standard (or alternative cleanup

level)  has  not been exceeded to successfully demonstrate compliance. Each

of these requirements is discussed below.



    a.    Points    of   Compliance-(1)   Ground   Water.   Proposed   Sec.

264.525(e)(1)(i)  would  establish  that  the  media cleanup standard would

generally  be  required  to be achieved throughout the area of contaminated

ground  water. This would require that, if the ground water were a drinking

water source, the entire plume of contamination would have to be cleaned up

to  levels acceptable for drinking. EPA is proposing this alternative since

exposure to contaminated ground water may potentially occur anywhere within

an area of ground-water contamination.



    Proposed   Sec.   264.525(e)(1)(i)  would  also  provide  the  Regional

Administrator  with  the  discretion to establish a point of compliance for

ground water at the boundary of the waste when waste is left in place. Such

discretion  may  be  necessary  where  it is impossible or inappropriate to

install  monitoring wells at certain locations. For example, in the case of

a  large  landfill,  it would usually be unwise to install monitoring wells

through the landfill itself. In addition, there will be circumstances where

ground  water  contamination  is  caused  by releases from several distinct

units  or  sources that are in close geographical proximity. In such cases,

the  most  feasible and effective ground-water cleanup strategy may well be

to  address  the  problem as a whole, rather than unit by unit, and to draw

the  plume  of contamination back to a point of compliance encompassing the

sources  of  release.  Proposed  Sec. 264.525(e)(1)(i) therefore explicitly

gives  the  Regional  Administrator  the  authority  to  set  the  point of

compliance at a line encompassing the original sources of the release.



    The  Agency  stresses  that  its general goal is to clean up the entire

plume  of  contamination;  however,  it  believes  that  for very practical

reasons  it  must  have  the  discretion  to  set  an  alternative point of

compliance  for  ground water around one or more common sources of release.

In  determining  where  to draw the point of compliance in such situations,

the  Regional  Administrator will consider such factors as the proximity of

the  units,  the  technical practicabilities of ground-water remediation at

that  specific site, the vulnerability of the ground water and its possible

uses, exposure and likelihood of exposure, and similar considerations.



    Further,  in  situations  where  there  would  be  little likelihood of

exposure  due to the remoteness of the site, alternate points of compliance

may be considered, provided contamination in the aquifer is controlled from

further migration.

    Proposed   Sec.   264.525(e)(1)(i)   provides   that  the  location  of

ground-water   monitoring   wells   will   be  specified  by  the  Regional

Administrator.  The  monitoring  wells  will  serve  both  to  monitor  the

effectiveness  of  the  ground-water  remediation program, and to allow the

permittee  to  demonstrate  compliance  with  the  media  cleanup standards

contained  in  the permit for releases to ground water. Where waste is left

in  place  (either  at  facility  closure  or at operating waste management

units),  {pg  30831}  wells will generally be located up to the boundary of

the waste (i.e., the unit boundary for operating waste management units).



    In establishing the point of compliance for remediation of ground water

for  today's  proposed rule, EPA considered several different alternatives.

These include the following:



     Throughout the ground water;



     At the hazardous waste unit boundary;



     At  the  edge of the existing contamination not to exceed a ''buffer''

zone  inside  the  facility  boundary (e.g., a line describing the point at

which  it would take at least five years for the contamination to reach the

facility boundary if it was left unabated); and

     At the facility boundary.



    The  alternative  considered by the Agency which would have established

the  point  of compliance at the facility boundary would recognize that the

likelihood  of exposure to ground-water contamination is extremely unlikely

on  the  property  of an actively managed facility. Owners and operators of

these   facilities   are   required   to   identify  and  monitor  existing

contamination  under  existing  regulations.  Where  existing contamination

would  result  in  exposure  (or  to  any contamination beyond the facility

boundary), owner/operators would be required to cleanup this contamination.

A  point  of  compliance  at  the  facility  boundary would reduce costs in

certain  cases,  while providing protection from adverse exposure. However,

the  Agency  is  not  proposing  this  alternative because it may allow the

spread  of  contamination  within  the  facility  boundary,  and provides a

smaller margin of safety than a more stringent point of compliance.



    Another alternative would be to set the point of compliance at the edge

of  the  existing contamination, with a ''buffer'' zone inside the facility

boundary.  This  would  prohibit  the continued spread of contamination and

provide  a  margin of safety between the facility boundary and any existing

contamination.  The  size  of  the  ''buffer''  could  be determined by the

expected  mobility  of  the  contamination  at that site. For instance, the

buffer  could  be  set  so  that  it  would  take  at  least five years for

contamination   to   reach   the   facility   boundary.   Once  identified,

contamination  entering  the  buffer  zone  would  be  required  to undergo

corrective action.



    EPA  requests  comments  on  its  proposal  and on alternatives to this

approach.  In  any  case,  if the Agency adopted a point of compliance less

stringent  than  the  waste unit boundary, the Regional Administrator would

have  the  discretion  to  adopt a more stringent point of compliance where

warranted by site specific characteristics.



    (2)  Air. Proposed Sec. 264.525(e)(1)(ii) would generally establish the

compliance point for hazardous constituents released to air at the location

of  the  most exposed individual. This is intended to be the point(s) where

maximum long-term human exposure would occur. It is expected that the point

of compliance will typically be outside the facility boundary.



    In  determining the location of the most exposed individual, the Agency

will  evaluate  the  risks where people spend a significant amount of their

time  on a daily basis rather than address temporary or transient exposures

to  air  emissions  (e.g.,  persons driving by the facility). Thus, cleanup

standards  might  be  set  at any dwelling, private, or public building, or

other  public  or  private area where exposures could occur on a regular or

continuous  basis  if  releases continue. This exposure might occur through

windblown  particles  (e.g.,  from  contaminated  soil), windblown volatile

emissions,  or  toxic gases migrating from the subsurface into dwellings or

other  structures.  These kinds of potential exposures are evaluated during

the facility investigation, and will generally require source controls when

they pose an actual or potential threat.



    In  establishing the location(s) of the most exposed individual(s), EPA

will  generally  not  include  on-site  facility workers, but would include

people who live on-site, such as military personnel and families who reside

at  a  Federal  facility  required  to  obtain  a RCRA permit. Occupational

exposures  generally  are the purview of the Occupational Safety and Health

Administration  (OSHA).  Under  OSHA Instruction CPL 2-2.37A of January 29,

1986, OSHA and EPA have agreed that OSHA has the lead role in providing for

the  safety  and  health  of  workers  at  hazardous  waste sites. OSHA has

established  standards  for such exposures in 29 CFR 1910.120. Although EPA

has  the  authority to address occupational exposures, it will generally do

so  only  when  the  Regional  Administrator  has  cause  to  believe  that

inadequate controls are being exercised at the site.



    The Agency believes that achieving compliance at the location of actual

human  exposure  will,  in  most  cases,  be fully protective. However, the

Agency  recognizes  that  some  sites  may present circumstances in which a

different compliance point may be necessary to protect human health and the

environment, and has provided the Regional Administrator the flexibility to

set  a compliance point other than at the most exposed individual. This may

particularly apply where exposure of environmental receptors are a concern.

For example, the Regional Administrator could specify that a permittee must

demonstrate  compliance  with  the  cleanup standard at the location of the

most exposed environmental receptor if site conditions warranted.



    The  Agency  considered  other  points  of compliance for media cleanup

standards  for  air, including the unit boundary and the facility boundary.

The  Agency,  however,  believes that requiring compliance with air cleanup

standards  at  these  locations would be unnecessarily stringent, and would

provide  very  little,  if  any,  real  additional  health or environmental

protection.  For  example,  if the point of compliance were set at the unit

boundary,   releases   from  the  unit  would  have  to  be  controlled  to

health-based levels, assuming life-time exposure at that unit. In practical

terms,  this  would  require  that  emissions  from  units  such as surface

impoundments  would  in some cases have to be controlled virtually to zero.

The  Agency  believes that such a standard would be unrealistic. Similarly,

the  Agency  believes that it is unnecessary to set the point of compliance

as  a  routine matter at the facility boundary, since in many, if not most,

cases  the actual location of exposed populations will be some considerable

distance from the site.



    As  discussed  earlier  in  today's preamble (section VI.E.2.d), action

levels  for  air are determined at the facility boundary in order to ensure

that  there will be a plan in place to address the contingency of receptors

moving  close  enough  to  the  facility  to  be  adversely affected by air

releases from SWMUs. Recognizing that residential patterns may change after

a  remedy has been selected and implemented, proposed Sec. 264.560(b) would

require  the  facility owner/operator to notify EPA and any individuals who

may  be exposed to the contaminated air if, at any time, air concentrations

exceed  the action level beyond the facility boundary. The need for interim

measures or additional studies would be assessed at that time.



    The  approach  proposed today for establishing points of compliance for

air  releases  differs somewhat from the proposed approach for other media,

such  as  ground water. This is due to basic differences in the behavior of

contaminants in air as compared to ground water. When a release into ground

water  occurs,  typically  the  resulting  ground- water contamination will

remain  at  or near the facility for an {pg 30832} extended period of time.

Thus, if the contamination is not remediated, exposure to the contamination

(i.e.,  through  drinking  water  wells) can occur for years thereafter. In

contrast,  when  a  release  into air occurs, typically it will migrate and

disperse  relatively  rapidly;  the  time  when individuals who are located

close  to  the  facility  could  be exposed to the air toxicants would be a

matter  of  minutes or hours. Thus, an air release that is occurring at any

given   time  does  not  present  a  long-term  exposure  threat  to  those

individuals,  as  would a ground-water release. Remedies for an air release

problem  will most often involve stopping or controlling the release itself

from  continuing  to  occur;  the  released  chemicals will not actually be

''cleaned up'' per se.



    Although the Agency recognizes that there can be other effects from air

releases  from solid waste management units (e.g., formation of ozone), the

general  objective  under  subpart  S  is  to  prevent  exposure  of nearby

individuals  to  harmful  levels  of  airborne  toxicants  and  carcinogens

released  from SWMUs (see section VII.C.3 of this preamble for a discussion

of  the  relationship  of  subpart S to section 3004(n) standards and ozone

concerns).  Therefore,  EPA believes that the proposed approach for setting

points  of  compliance  for  air releases at the most exposed individual is

sensible  and  realistic.  Requiring compliance at the unit boundary (which

would  follow  the  approach  for ground water) would, in essence, create a

standard based on protecting against an implausible exposure scenario.

    Proposed   Sec.  264.525(e)(1)(ii)  also  provides  that  the  Regional

Administrator  will  specify locations where air monitoring devices must be

installed  and  what  emission  modeling or testing, atmospheric dispersion

models,  or  other methods must be used to demonstrate that a permittee has

achieved   compliance   with   the  media  cleanup  standards.  Methods  of

demonstrating  compliance with air cleanup standards will vary from site to

site.  At many sites, emission modeling or monitoring air close to the unit

may  be  coupled with air dispersion modeling to estimate concentrations of

hazardous  constituents  at  the  point  of  compliance.  At  other  sites,

monitoring of air quality at the actual point of compliance may be the most

accurate  and  reliable  method  of demonstrating compliance with the media

cleanup  standard. In other cases, corrective measures taken to control the

source  of the release may eliminate the release to air altogether. In such

cases,  continued  air  monitoring  or  modeling  would  not  generally  be

required.



    (3) Surface Water. For surface water, the Agency is proposing the point

where  releases  enter  the  surface water as the point of compliance. (See

Sec.  264.525(e)(1)(iii).)  This compliance point will be used for releases

to  surface  water  that  are  ongoing,  such  as  would  be  the case with

contaminated  ground  water  that  flows  into  a  surface  water  body, or

non-point  runoff  which occurs during rainfall events. The Agency believes

that achieving compliance with the media cleanup standard for such releases

at  the  point of entry into surface water will be necessary to assure that

human health and the environment are protected.



    EPA  recognizes,  however, that in some cases releases from solid waste

management   units  that  have  occurred  in  the  past  have  settled  and

accumulated   in   surface   water   sediments.  Where  actual  cleanup  of

contaminated sediments is determined to be necessary, and cleanup standards

have  been specified for the sediments in the context of a remedy, proposed

Sec. 264.525(e)(1)(iii) would allow the Regional Administrator to designate

locations  (i.e.,  areas and depths in the sediments) where compliance with

the standards would be required.



    The  Regional  Administrator  will  specify the locations where surface

water  must  be sampled to monitor the water quality. The Agency recognizes

that  in  some cases (e.g., fast moving streams) there may be some dilution

of  hazardous  constituents  before  samples can be collected; however, the

goal in establishing sampling locations should be to minimize such dilution

effects.  The  Regional  Administrator  also  may  specify  locations where

sediment  samples  will be collected and analyzed to demonstrate compliance

with  media  cleanup  standards.  Such  considerations will be particularly

important  where  the surface water is an important environment for aquatic

life  and/or  fish  or other organisms which are likely to be ingested by a

nearby population.



    (4) Soils. Today's proposal would establish the point of compliance for

soils at any point where direct contact exposure to the soils may occur. In

most  cases  this  point will be near the surface of soils, because this is

where the greatest likelihood exists of human contact.



    b.  Methods.  Under  Sec.  264.525(e)(2),  the Agency proposes that the

Regional  Administrator  specify  in the permit the sampling and analytical

methods  to  be used, methods of statistical analyses, if required, and the

frequency  of  sampling  or monitoring that may be required to characterize

levels   of  hazardous  constituents  in  all  media,  and  to  demonstrate

compliance with media cleanup standards (or alternative cleanup levels). In

many  cases  the  permittee  may  have  proposed, in the Corrective Measure

Study,  sampling  and  other analytic methods that would be appropriate for

the  remedial alternative as part of an implementability or availability of

needed  services  analysis.  In  such cases, the Regional Administrator may

consider  and  adopt  the  proposed  methods  or  other methods that he/she

believes  to  be  more  appropriate  for  the  environmental  problem being

addressed  or may require the parmittee to use methods he/she believes more

reliable.

    c.  Timing of Demonstration of Compliance. The Agency is also proposing

under  Sec.  264.525(e)(3)  that  the Regional Administrator specify in the

remedy  the length of time during which the permittee must demonstrate that

concentrations  of  hazardous  constituents  have  not  exceeded  specified

concentrations  in order to achieve compliance with media cleanup standards

(or  alternative  cleanup levels). Under the existing subpart F regulations

(Sec.  264.100),  the  Agency  has  required  that facility owner/operators

remediating   ground-water  contamination  from  regulated  units  continue

corrective action until the designated ground-water protection standard has

not  been  exceeded for a period of three years. The Agency has found that,

given   the   variety   of   hydrogeologic   settings   of  facilities  and

characteristics   of   the  hazardous  constituents,  it  is  difficult  to

demonstrate  reliably  that  the  ground-water protection standard has been

achieved by imposing a uniform time for demonstrating compliance.



    The  Agency is not proposing a specific time period under the subpart S

regulations   for   achieving  compliance  with  cleanup  standards  before

discontinuing  corrective action. Instead, the Agency is proposing that the

Regional  Administrator  specify the length of time required to make such a

demonstration  as  appropriate  for  a  given  media  cleanup  standard. As

described   under   proposed   Sec.  264.525(e)(3)  (i)-(v),  the  Regional

Administrator may consider five factors in setting this timing requirement:

(1)  The  extent  and  concentration  of  the  release;  (2)  the  behavior

characteristics  of  the hazardous constituents in the affected medium; (3)

the  accuracy  of  the  monitoring  techniques;  (4) characteristics of the

affected   media;   and,   (5)   any  seasonal,  meteorological,  or  other

environmental  variables  that  may  {pg  30833} affect the accuracy of the

monitoring results. The Agency believes that consideration of these factors

will allow the Regional Administrator to set an appropriate time period for

demonstrating  compliance  with cleanup standards rather than relying on an

arbitrary  time  period  for  all  facilities or all situations at the same

facility.



    One  example of how these considerations might affect a decision on the

time  a  cleanup standard must not be exceeded to demonstrate compliance is

given here. The Agency expects that pump and treat systems will be required

at  many  facilities  where hazardous wastes or hazardous constituents have

migrated  to  ground  water  from  SWMUs.  Experience in the RCRA subpart F

program (which addresses releases of hazardous constituents to ground water

from  regulated  units)  has  shown that continuous operation of a pump and

treat  system  may  interfere  with  the owner/operator's ability to obtain

accurate  sampling  data  on  constituent  concentration  levels.  Allowing

natural  restoration  of  chemical equilibrium in the affected ground water

after  the  pump and treat system is turned off will be necessary to obtain

accurate  readings  of  constituent concentrations. If the concentration(s)

rise  to unacceptable levels after the remedial technology is disconnected,

reinitiation  of  treatment  may be required. This process would have to be

repeated  until acceptable concentration levels are achieved after chemical

equilibrium  has been reached in the ground water with the treatment system

suspended.  In  such  cases  it  may be necessary to extend the life of the

permit  until  required remedial results have been achieved even when waste

management  operations  have  ceased at all active hazardous waste units at

the facility.



    8.  Conditional  Remedies  (Sec.  264.525(f)). Proposed Sec. 264.525(f)

would  allow  EPA  to select a ''conditional'' remedy. A conditional remedy

would   allow,   at   EPA's   or  the  authorized  State's  discretion,  an

owner/operator  to  phase-in  a  remedy  over  time,  as  long  as  certain

conditions  are  met.  EPA recognizes that in some cases completing cleanup

will  be  sufficiently  complex  and costly to warrant a phased approach to

cleanup. Generally, a conditional remedy would allow existing contamination

(sometimes  at  existing  levels)  to  remain within the facility boundary,

provided  that  certain  conditions are met. These conditions would include

achieving  media  cleanup  standards  for  any  releases that have migrated

beyond  the  facility  boundary as soon as practicable, implementing source

control  measures  that will ensure that continued releases are effectively

controlled, controlling the further migration of on-site contamination, and

providing  financial  assurance for the ultimate completion of cleanup. The

length  of  time  that  contamination could be allowed to remain within the

facility  boundary would be established on a site-specific basis, but could

be  for as long as the permit remains in effect. Nothing in this provision,

of  course, would prevent the transfer of property subject to a conditional

remedy or other corrective action requirements. For a further discussion of

the property transfer issue, see section VI.L.1. of this preamble.



    This  type  of  remedial  approach  may  often  be appropriate for RCRA

facilities,  for  several  reasons.  First,  permitted RCRA facilities will

typically  be  actively managed properties, with viable owner/operators who

can  control  and  restrict  access to the property. Typically, exposure at

such  facilities  (which  have  permits  to manage hazardous waste) will be

significantly less than at sites where access is unrestricted. For example,

actual  drinking  of  ground  water  under  the facility will not generally

occur, nor would residences typically be found-as long as the site remained

a RCRA permitted facility. Therefore, an appropriate remedy for such a site

might  be  the  cleanup  of  ground water contamination under the site to a

level   consistent  with  current  exposures.  Most  RCRA  facilities  pose

significantly  lower  environmental  and  human health risks than Superfund

sites, and therefore the need to pursue complete cleanup at such facilities

will  often  be less urgent. The use of conditional remedies in appropriate

situations complements EPA's overall management goal of addressing the most

significant and urgent environmental problems first.



    The Agency anticipates that there may be a variety of facility-specific

situations under which a conditional remedy would be appropriate, given the

nature  of  the  contamination problem at the facility, the capabilities of

the  owner/operator  and  other factors such as the level of risk and local

public   concerns.  One  example  could  be  a  large  facility  where  the

contaminant  sources  and releases are of no current threat, are relatively

remote  from  any  potential  receptors  and  can be reliably controlled to

prevent  further  significant degradation, and where the owner/operator can

be  reasonably expected to maintain an effective, long-term presence at the

facility,  and  thus  able  to  prevent exposure to contaminants during the

conditional   remedy.   EPA   recognizes   that   decisions  regarding  the

appropriateness   of   conditional  remedies  could  often  have  important

implications  for owner/operators, as well as others who may be affected by

or  who  have  interest  in the long-term environmental conditions of these

facilities.  Such  decisions  must  be  made  in  careful  consideration of

relevant,  site-specific  factors. The Agency specifically requests comment

regarding  which  factors  should  be considered-and how-in determining the

appropriateness  of  conditional remedies, and whether more formal criteria

should be specified in the rule for making such decisions.



    Conditional  remedies  would not be appropriate in situations where EPA

or   the   authorized   State   lacks  reasonable  assurance  that  further

environmental degradation will not occur. For example, a conditional remedy

would  not  be  appropriate  in  the  case  of  a  fast  moving plume or in

circumstances  where  the hydrogeology of the area suggests that additional

vertical   migration  will  likely  occur  despite  the  implementation  of

engineered   systems  or  devices  to  control  plume  migration.  Further,

conditional remedies may not be appropriate in situations where a site with

ground   water   contamination   is   located  in  close  proximity  to  an

environmentally   sensitive  area.  In  the  case  of  Federal  facilities,

conditional  remedies  may  be  frequently used because of a combination of

factors, including technical limitations on the ability to achieve complete

cleanup  at facilities which are often extremely large and complex, and the

unique  financial constraints placed on Federal facilities by the nature of

the federal budget process.



    The  media  cleanup standards, source control actions, or other actions

required  under  a  conditional  remedy  may or may not be sufficient for a

final  remedy.  Today's  rule  recognizes  that  in  some  cases, there are

technical  limitations  to  achieving  complete  cleanup  of  ground  water

contamination.   The   proposal   recognizes   this  and  allows  technical

practicability  to  be  factored  into  the  decisionmaking  process  at  a

particular site both during the selection of remediation alternatives to be

considered and in the final determination of appropriate remedies.



    The  Agency  is  particularly interested in comments on this issue from

the States, who will ultimately be the implementing agencies for corrective

action.  Comments are solicited as to whether States support this approach,

and  whether  they  believe  it  reasonably {pg 30834} addresses corrective

action problems at facilities operating under State permits.



    Section  264.525(f)(2)  outlines  the  seven  specific  requirements-or

conditions-that  conditional remedies must comply with. Should any of these

conditions  not  be  met  during the term of a facility's permit, EPA would

either impose new or additional conditions to ensure protection, or require

the  owner/operator  to  implement  a ''final'' remedy; i.e., a remedy that

fully  meets  the  standards of Sec. 264.525(a). In any event, such a final

remedy  would  ultimately  have  to  be  implemented  and  completed at the

facility before termination of the permit.



    Under  a  conditional  remedy  the  owner/operator would be required to

achieve  media cleanup standards for any releases that have migrated beyond

the facility boundary as soon as practicable. In addition, the remedy would

have  to  prevent against any further significant environmental degradation

This  will typically involve implementing source control measures that will

ensure  that  continued  releases (e.g., leachate from a landfill to ground

water)  are  effectively  controlled.  In order to achieve this standard of

protection,  substantial  treatment of wastes or other containment measures

will  often  be  required.  In  addition to such source control measures, a

conditional  remedy  would  also be required to have implemented engineered

systems  or  devices  to  control the further migration of on-site releases

that  have  already  occurred.  For  example,  in  the  case  of a plume of

''on-site''  contamination  (i.e.,  that  had  not yet reached the facility

boundary),  that  would  continue  to  migrate  and further contaminate the

aquifer if left unchecked, the owner/operator would be required to install,

at  a  minimum,  some  type  of ground-water interception system or barrier

system that would reliably halt such continued migration.



    The   source   control  actions  or  other  actions  required  under  a

conditional  remedy to prevent further environmental degradation may or may

not  be  sufficient for a final remedy. In some cases, further treatment of

wastes  or  extra  engineered  features  might be required to achieve final

remedial  goals,  consistent  with  the  provisions for remedies under Sec.

264.525  (a)  and  (b).  Likewise,  the  final  remedy  would  also require

compliance  with standards for attaining media cleanup standards within the

facility boundary, as well as outside the facility.



    Under  a  conditional  remedy,  any  treatment,  storage or disposal of

wastes  required by the remedy would have to be done in accordance with the

requirements  for  management  of  wastes,  as  specified in proposed Secs.

264.550-264.559.



    Today's  proposal would require that financial assurance for the remedy

be  demonstrated.  The Agency recognizes that financial assurance may often

be very important in ensuring the effectiveness of a conditional remedy, as

well  as  ensuring  that  final  cleanup  of the facility will be achieved.

Comment  is  solicited  as to the types of financial assurance requirements

that should be imposed on conditional remedies.



    Since  a conditional remedy may allow some contaminated media to remain

on  the facility during the course of the remedy, a critical feature of the

remedy  will  be  ensuring adequate controls to prevent against exposure to

such  contamination.  Controls could be engineered features, such as fences

or  other  physical  barriers  to  restrict  access  to  those areas of the

facility.  Other  non-engineered controls, such as prohibitions against use

of  on-site  ground  water  for  drinking water, could also be required and

written into the permit.



    EPA  solicits  comments on the overall concept of conditional remedies,

and  on  the specific conditions and requirements that should be imposed in

implementing such remedies.



G. Permit Modification for Selection of Remedy (Section 264.526)



    After a preliminary selection of remedy, the Agency will need to revise

the  permit  to incorporate the remedy. This decision (selection of remedy)

is a major one in the corrective action process, and the public is entitled

to  review  and  comment  on  the  Agency's preliminary decision concerning

appropriate   remedial   activities   at   the   facility.  Moreover,  this

modification   provides  an  opportunity  for  the  public  to  comment  on

activities (e.g., the remedial investigations and the CMS) that have led up

to  the identification and selection of the remedy. As a result, the Agency

believes that a major modification of the permit is appropriate. Therefore,

the  Agency is proposing today in Sec. 264.526(a) to require a major permit

modification for the purpose of specifying the selected corrective measures

and imposing a schedule of compliance for implementing the remedy.



    The regulatory authority for a major permit modification is found in 40

CFR  270.41,  as  amended  by  proposed  Sec.  270.41(a)(5)(ix)  of today's

regulation.  No  changes  are  being proposed in today's rule for the major

modification  process, which requires a 45-day notice and comment period, a

response  to comments, and a public hearing if such a hearing is requested.

(Regulations concerning standards for major modifications are located at 40

CFR 270.41; governing procedures are found in 40 CFR part 124.)



    Opportunities  for  public involvement in the corrective action process

beyond  the  modification  for selection of remedy are discussed in Section

VIII of today's preamble.



    Proposed  Sec.  264.526(b)  specifies  seven  elements  that  would  be

included  in  the  modified  permit.  The  proposed  modification  and  its

accompanying  statement of basis would provide a framework for the facility

owner/operator's  and the public's understanding of the remedial activities

selected  for  the facility. First, the proposed modification would have to

include  a description of the technical features of the remedy necessary to

achieve  standards for remedies as stated in proposed Sec. 264.525(a). This

description  must be complete enough to enable a reviewer to determine that

it  complies  with  the  standards  for protectiveness, attainment of media

cleanup  standards,  source control, and waste management practices imposed

on all RCRA remedies under Sec. 264.525(a). For instance, if an incinerator

is  to  be constructed to incinerate waste at the facility, the description

would  generally  indicate  the  type of incinerator proposed, the part 264

performance  standards  the  incinerator would meet, the capacity, etc. The

remedy  description might also need to specify equipment or design features

needed  to  address  air  releases  from  the  treatment process (e.g., air

strippers  used  to  remove volatile organics will generally be required to

have  a  control  device  such  as a carbon adsorption unit). The technical

features  required  should  be  provided  in  sufficient  detail  to  allow

meaningful  comment  and  to  provide  the  facility  owner/operator  clear

guidance  in developing a remedial design. (See discussion of remedy design

under  section  VI.H  of  today's preamble.) At the same time, EPA believes

that  many  details  of the remedy-for example, the operating conditions of

the  incinerator  needed  to  meet  the  performance standards or the exact

nature of emissions control devices on tanks-might not be available at this

stage and would be addressed during approval of the remedy design.



    Second, today's proposal would require in Sec. 264.526(b)(2) that media

cleanup  standards  established  during remedy selection be included in the

modified permit. {pg 30835}



    Third,  proposed  Sec.  264.526(b)(3)  would  require that the modified

permit  describe  conditions  the  permittee  must  fulfill  to demonstrate

compliance  with  the  media  cleanup  standards  established in the remedy

selection  process  under Sec. 264.525(e). For example, the modified permit

might require the owner/operator to continue monitoring ground water over a

certain period of time after a cleanup standard has been achieved to ensure

that  the level is not subsequently exceeded. In addition, the permit might

specify where ground water would be monitored to measure compliance. Again,

specific  details  on  compliance  measurements  might  not be available at

remedy selection, but would be addressed through remedy design.



    Proposed Sec. 264.526(b)(4) would require the Regional Administrator to

specify  standards applicable to the management of corrective action wastes

in  the  permit.  For  example,  if  the remedy selected specifies use of a

temporary  tank  at  the  facility  for the purpose of waste treatment, any

design,   operating  or  performance  standard  deemed  applicable  to  the

operation  of  the  unit  would  be  included in the modified permit by the

Regional Administrator.



    Fifth,   any   procedures   the   permittee   must  follow  to  remove,

decontaminate,   or   close   units   or   structures  used  during  remedy

implementation   would   be  specified  in  the  permit,  as  well  as  any

post-closure  care  required.  In  the  example  of the temporary unit used

above,  the Regional Administrator would specify any closure standards that

applied  to  the temporary unit if the unit was employed to treat hazardous

waste.



    Proposed  Sec.  264.526(b)(6)  would  require  that the modified permit

include  a  schedule  for  initiating  and  completing  all major technical

features and milestones of the remedy.



    Finally,  the  modified  permit must include (under Sec. 264.526(b)(7))

any  requirements  for  submission  of program reports or other information

deemed   necessary  by  the  Regional  Administrator  for  the  purpose  of

overseeing  remedy  implementation  and progress. For further discussion of

the remedy selection process and components of the decision-making process,

see section VI.F of today's preamble.



    The  Agency  believes  that these minimum requirements-a description of

the  remedy's  technical  features,  the  cleanup  standards  that  must be

achieved, the standards that must be met to demonstrate compliance with the

media   cleanup  standards,  standards  applicable  to  the  management  of

corrective   action  wastes,  requirements  for  removal,  decontamination,

closure,  or  post-closure  of  units  or  devices  employed  during remedy

implementation,   a   schedule   of   compliance,   and   requirements  for

reporting-are  the  most  important  decisions  the  modified  permit  must

reflect.  Further,  they  are  essential  to inform the public fully of the

Agency's  preliminary decision when the draft permit modification is issued

for notice and comment.



    In  addition to the draft permit modification itself, EPA would also be

required   to  publish,  under  the  permit  modification  requirements,  a

statement of basis. This statement, which would be roughly analogous to the

Superfund  Record of Decision (ROD), would generally describe the basis for

EPA's  tentative  remedy  selection  or approval and an explanation for the

cleanup  levels  chosen. In addition, EPA would generally make the remedial

investigation  and  the CMS reports available to the public for review. The

scope  and  content of the statements of basis will vary widely, of course,

depending on the complexity of the site, the nature of the proposed remedy,

the level of public interest, and other relevant factors. In any case, they

should   be   sufficiently   detailed  for  the  public  and  the  facility

owner/operator   to  understand  and  comment  on  the  Agency's  tentative

decision, and the studies and conclusions leading up to the decision.



    The  permittee,  based on the remedy selected and approved in the final

modified  permit,  will  be  required  under  proposed  Sec.  264.526(c) to

demonstrate  financial  assurance  for  completing  all  required  remedial

actions  specified  in  the  modified  permit. The proposed regulations for

financial  assurance  for  corrective  action  (FACA)  (51  FR  37854),  as

discussed  in sections IV.D and VII.C.5 of today's preamble, may be used as

guidelines  by  owner/operators  for  demonstrating  the required financial

assurance.



    Today's  proposed  Sec.  264.526(c)  would  require  the  permittee  to

demonstrate  financial  assurance no later than 120 days after the modified

permit  becomes effective. The Agency believes that this approach is needed

since the remedy proposed for the facility in the draft permit modification

may  be  altered  in  response to comments, and since final detailed remedy

design,  construction,  operation, and maintenance plans which will provide

significantly  improved cost estimates may not be submitted until after the

modified  permit  is  in  effect.  The  Agency  chose  120  days to promote

consistency  with  other RCRA financial assurance provisions. Experience in

implementing  the  financial  assurance  provisions  under 40 CFR part 264,

subpart  H,  has  shown  that  120  days is a reasonable period of time for

owners or operators to obtain financial assurance mechanisms. The Agency is

specifically  soliciting  comment  on  this  proposed  provision today, and

whether  120  days  after  the  final  remedy  decision  is  imposed  is an

appropriate length of time for demonstrating financial assurance.



    In  addition,  proposed  Sec.  264.525(c)(2)  would  allow the Regional

Administrator   in   certain   circumstances   to   release   the  facility

owner/operator's   mechanisms  establishing  financial  responsibility  for

closure   and  post-closure  financial  assurance  at  the  time  financial

assurance for corrective action is established. This amendment is necessary

to  address  situations  where  corrective action is conducted at regulated

units-particularly  under  the  subpart F requirements of Sec. 264.100- and

the  corrective  action  schedule of compliance replaces the unit's closure

plan.  In  these  cases,  it will generally be appropriate for the Regional

Administrator to release the facility's financial assurance for closure and

post-closure  for  that unit and allow the facility to apply the mechanisms

to  financial  assurance  for  corrective action. In addition, at the point

where  the  unit  subject  to  corrective  action  is effectively closed in

accordance  with the corrective action schedule of compliance, the Regional

Administrator  would  have  the authority under today's proposal to release

the  owner/operator from third-party liability requirements with respect to

that  unit.  This  proposed  requirement  is  consistent  with  the current

provisions  of  subpart  H,  which  generally  provide  for  the release of

third-party  liability  mechanisms  at the time an owner/operator certifies

final closure.



    Section   264.526(d)  provides  for  phased  remedies  when  considered

appropriate  by  the Regional Administrator. The concept of phased remedies

is  similar  to  the  designation of ''operable units'' in CERCLA. Remedial

actions  at  CERCLA sites are often managed in stages called operable units

since  it  is  often not feasible, for a variety of reasons, to clean up an

entire  site in one action. Operable units under CERCLA, or remedial phases

under RCRA, may consist of any logically connected set of actions performed

sequentially over time, or concurrently at different parts of a site.



    One  example  of  a situation where a phased remedial approach would be

useful  is  where treatment of waste is desirable, but where a suitable {pg

30836} treatment technology or adequate treatment capacity is not currently

available,  although  it  is  expected  to  be available in the foreseeable

future.  In  such cases, remedial phases might consist initially of limited

measures  to  stabilize  the  wastes, to be followed by a complete response

action  when  an  appropriate  treatment  teohnology  or  capacity  becomes

available.



    Another  example of a phased approach would be a requirement to install

a  ground-water  pump  and  treat  system  to control further movement of a

contaminant  plume  and  begin the cleanup process, prior to specifying the

source  control  measures  necessary for the releasing unit(s). Conversely,

source  controls at a SWMU (or SWMUs) might be required prior to installing

the  pump  and  treat  system. This kind of approach would be desirable, in

many  cases,  where  the  disintegration of the engineered structure of the

unit(s)   is   resulting   in   continued  significant  releases,  but  the

concentration  of  the  hazardous  constituents in the ground water had not

reached  levels  or locations that threaten exposure of humans or sensitive

environmental  receptors to hazardous constituents at harmful levels in the

near term.



    Any  initial remedy phases should be consistent with, and complementary

to,  the  final  remedy  that  is  selected  according to Sec. 264.525. The

separation of a remedy into phases should in no way impede future cleanups;

rather,  this  approach  should  often  be useful in taking early action to

prevent further degradation while other problems are still in a study phase



    The  Agency has determined that the use of phased remedies for managing

corrective  action  at  RCRA facilities is appropriate for many of the same

reasons  the  concept  is used at Superfund sites. Using remedial phases at

RCRA  sites  will  provide  the  Agency  with  more  flexibility to require

remedies  tailored  to site-specific considerations. It may be advantageous

at  a  particular RCRA facility to address releases from an individual SWMU

or group of SWMUs in stages, focusing first on those releases that pose the

greatest  risk to human health and the environment, while allowing releases

posing less risk to be addressed later.

H. Implementation of Remedy (Sections 264.527-264.531)



    1.  Remedy  Design  (Sec.  264.527).  After EPA has approved the remedy

through  the  permit modification process, the facility owner/operator will

often  be  required  in  the  modified  permit  to develop a remedy design.

Proposed  Sec.  264.527  would  require  the  permittee to prepare detailed

construction  plans  and  specifications  for  implementing the remedy. The

schedule  for  submission  of  the plans would be included in a schedule of

compliance  detailed  in the permit. This proposed requirement is analogous

to  the  Superfund  program's  adoption  of  design standards following the

Record  of Decision on remedy selection. The Agency would approve or modify

the design and incorporate it into the schedule of compliance.



    Designs  required  under  Sec. 264.527 must include specifications that

demonstrate  compliance  with  the  applicable  standards for management of

hazardous  and/or  solid  wastes  during  implementation  of the remedy, as

determined  by  Secs.  264.550  through  264.552  of  today's proposal. The

information required would be similar to the information typically required

about units and processes at facilities in part B applications.



    The  permittee  would  also  be required under proposed Sec. 264.527 to

submit  implementation and long-term operation, monitoring, and maintenance

plans, a project schedule, and a program to assure quality assurance during

the  construction phase (if any) of remedy implementation. Such information

would include specific dates for major milestones and project completion as

well as other significant events.



    Proposed  Sec.  264.527(b) would require the permittee to implement the

remedy  according  to  the  plans  and  schedules  approved by the Regional

Administrator  and in a manner consistent with the objectives specified for

the  corrective  measures  during remedy selection. Section 264.527(a) will

provide that the approved schedule and specifications become an enforceable

part of the permit.



    Proposed Sec. 264.527(b)(2) would require the permittee to place a copy

of  the  approved  design  plans  and  specifications  in  the  information

repository  if  the  facility  is required by the Regional Administrator to

maintain  such  a  repository  under  the  authority  of  Sec.  270.36. All

permittees would be required, under proposed Sec. 264.527(b)(3), to provide

written  notice  of  approval  of  remedy  design  to  those persons on the

facility  mailing  list.  This  notice  would  provide  individuals  on the

facility  mailing  list  a  notice  of  the location of the approved remedy

design  and  specifications  and provide information on the availability of

those documents for public review.

    Additionally,  proposed  Sec. 264.527(b)(4) would require the permittee

to  amend  the  corrective  action  cost  estimate and adjust the amount of

financial  assurance  demonstrated,  if  necessary,  after  approval of the

remedy  construction  plans  and  specifications.  These plans will provide

improved  cost estimates compared to those developed during modification of

the  permit.  Therefore,  to  ensure  that  adequate  amounts  of funds are

available  to  cover  corrective  action  costs,  the  amount  of financial

assurance  demonstrated must reflect the revised cost estimate derived from

the final construction plans and specifications.



    2.  Progress  Reports  (Sec. 264.528). Since implementation of remedies

will  often  take place over extended time periods, Sec. 264.528 of today's

proposal  provides  that  the  Regional  Administrator may require periodic

progress  reports  from  the  permittee. These progress reports may contain

information  on  construction,  operation,  and maintenance of the selected

remedy.  The  Regional Administrator would specify the frequency and format

of  such  reports  in the permit schedule of compliance, when s/he approved

the remedy design. Such reports would be designed to summarize the progress

of  remedy implementation, discuss changes or problems with the remedy, and

provide data obtained during remedy implementation.



    The timing and content of progress reports will vary from site to site.

Factors  that may be used by the Regional Administrator in determining what

progress  reports  are necessary for a given site include complexity of the

waste  mixture,  complexity  of  the  remedy,  hydrogeologic  and  climatic

conditions,  and  potential  for  exposure.  These  factors are qualitative

measures of the risks posed by contamination at a specific site. The Agency

intends  to  monitor  closely those sites at which the risk to human health

and  the  environment  is  greatest. For example, the frequency of progress

reports  may  be greater at sites where there are complex remedies and/or a

high  potential  for exposure to contamination than at sites where remedies

are simple and the potential for exposure is low.



    Reports required by the Regional Administrator will be tailored to meet

site-specific conditions. Where necessary, progress reports may be required

to  contain  detailed information on remedy implementation. In other cases,

such  as  where  the  remedy  is  simple,  the progress reports may be less

detailed.



    The  Agency  considered  several  alternatives  to today's proposal for

allowing  discretion  to  the  Regional Administrator in requiring progress

reports.  These included: Not requiring progress reports from any facility;

requiring  submission  of  reports  on  a {pg 30837} routine basis from all

facilities  implementing  remedies;  and  requiring development of progress

reports  which  would  be  kept  on  file at the facility and available for

inspection  by EPA. The Agency has tentatively rejected these alternatives,

because  it  believes  that  the  variation  among  sites will require that

reporting  (including  frequency  of reporting) be tailored to the specific

site.



    All  raw  data  and  information  developed  or submitted during remedy

implementation   (including  design,  laboratory  reports,  etc.)  must  be

maintained  in the operating record of the facility as long as the facility

operates  under  a  RCRA  permit,  including  any reissued permit following

initiation  of  corrective  action.  This  requirement  is proposed in Sec.

264.528(b)  and  is  necessary  to ensure that periodic reviews at the site

will have all data available for inspection.



    3. Review of Remedy Implementation (Sec. 264.529). Under the regulatory

authority proposed in Sec. 264.529, EPA would review remediation activities

on  a  periodic  basis. Such reviews will take place throughout the design,

construction,  operation, and maintenance of the corrective measure(s). The

Agency's  review of remediation activities will consist both of a review of

progress  reports  submitted by the permittee and, where necessary, on-site

inspections  and  oversight  of remedy design, construction, operation, and

maintenance.  The  Agency  intends  to  focus  on-site inspections on areas

identified for oversight in progress reports or prior Agency reviews.



    The  Agency  believes  that  the  authority to perform close reviews of

remediation  activities  is  an  essential element of the corrective action

program.  Experience  in  the HSWA corrective action program and the CERCLA

remedial  program  has  demonstrated  that  timely  and  close oversight of

cleanup  activities  is essential in many cases to ensure that remedies are

effectively  implemented. For example, oversight of the remedy may indicate

that  the  technology  originally  called for in the design plans is not in

fact  successfully  meeting  the  media  cleanup  standards.  Proposed Sec.

264.529  provides  EPA  with  the  authority  to  take steps to remedy such

implementation problems.



    The Agency intends to work closely with permittees by overseeing remedy

implementation  and  addressing problems in a timely manner. Where problems

arise during implementation of the selected remedy, the Agency will attempt

to  settle  such  problems  informally  with  permittees  to  ensure prompt

completion of the remedy in a manner which adequately protects human health

and  the  environment.  In  some  cases,  the  Agency may determine that an

enforcement  action under section 3008(a) is necessary to compel compliance

with  the  permit.  In  other  cases,  where no resolution of disagreements

appears  possible,  or  where  the contemplated change is one that warrants

additional  public  participation,  proposed  Sec.  264.529 would allow the

Regional   Administrator  to  initiate  a  permit  modification  using  the

procedures  laid  out  in  40 CFR 270.41 or those proposed today under Sec.

270.34(c).  If the Regional Administrator believes that a disagreement over

a  proposed  provision  is suited to alternative dispute resolution, she/he

may  seek  resolution  using  the procedures described in section VI.L.7 of

today's  preamble.  A  more  detailed discussion of circumstances which may

require  permit  modifications  may  be  found  in  section VI.L of today's

preamble.



    The  Agency  also considered, but rejected, requiring a specific number

of  facility  inspections during remedy implementation. Because the variety

of  problems to be addressed under today's proposed regulation is extensive

(as  is  the  range  of  proven  reliability  of  technologies which may be

employed to address the problems, complexity of the site, and potential for

exposure),  the Agency has concluded that frequency of site reviews must be

a case-by-case decision.



    4.  Completion  of Remedies (Sec. 264.530). Proposed Sec. 264.530 would

establish  criteria  by  which  the  owner/operator  would  demonstrate the

completion of remedies.

    Section  264.530 would specify that corrective measures required in the

permit  are  complete  when  three  conditions  have been met. First, under

proposed Sec. 264.530(a)(1), the requirements for compliance with all media

cleanup  standards  (or  alternative  cleanup  levels)  as specified in the

permit  would  have to be met. For example, if both a ground-water and soil

cleanup  standard  are  specified  in the permit, the cleanup standard must

have  been achieved for each medium before the facility meets the criterion

of  compliance  with  all  media  cleanup  standards.  In  addition,  after

initially  achieving  the cleanup standard the permittee generally would be

required  to  monitor the medium for an additional period of time to ensure

that  the  remedy  was in fact complete and that contaminant levels did not

subsequently  exceed the cleanup standards under the provisions of proposed

Sec.  264.525(e). This requirement is discussed in section VI.F.7.c of this

preamble.



    Second,  under proposed Sec. 264.530(a)(2), all actions required in the

permit  to  address  the  source or sources of contamination must have been

satisfied. This provision is designed to prevent continued contamination in

the   future.  One  type  of  source  control  which  may  be  required  is

construction  of  a  structurally  sound cap on an inactive SWMU to prevent

future  contaminant  migration  to  surface  water  which could potentially

result from rainfall runoff from an uncovered SWMU.

    Third,  under  proposed Sec. 264.530(a)(3), the permittee would have to

comply   with   procedures   specified   in   the  permit  for  removal  or

decontamination  of  units,  equipment,  devices, or structures required to

implement  the  remedy.  In  other words, temporary structures or equipment

necessary  to  conduct  the  remedy  must  be  removed or decontaminated to

complete the remedy. For example, liners or the contents of temporary waste

piles  would  have  to  be  disposed  of  according  to  appropriate  waste

management  practices.  Units  employed  during  the remedial activities to

manage  hazardous  waste  will  be required to meet the closure performance

standards for the appropriate type of unit. (Closure would not be required,

of  course,  if  the  owner/operator  wished to continue use of the unit to

manage waste and continued use was allowed in the permit.)



    Proposed  Sec.  264.530(b)  would  establish procedures that permittees

must  follow  to  document  that corrective measures have been completed in

accordance with the requirements of Sec. 264.530(a). Upon completion of the

remedy,  the  permittee would be required to submit a written certification

to  the  Regional  Administrator by registered mail stating that the remedy

has  been  completed in accordance with the requirements of the permit. The

certification  must  be  signed  by  the  permittee  and  by an independent

professional  skilled  in  the appropriate technical discipline. The Agency

believes  that  a certification by an independent professional is necessary

because  the  permittee  may  lack the expertise and the incentive to judge

adequately  the  compliance  of the remedy with the applicable requirements

specified in the permit.



    The  Agency  is  not  proposing  to  specify  the  types of independent

professionals  who  must  certify  completion  of  the  remedy.  The Agency

proposes   to   require   certification   by   an  appropriate  independent

professional  in  recognition  that different certifications {pg 30838} may

require  different  skills  (e.g.,  an  engineer may be appropriate in some

cases whereas a hydrogeologist might be more appropriate in another).



    The  Agency  considered,  but  is not proposing, a requirement that all

supporting  documentation  be  submitted  along  with  the  certificate  of

completion.  Since,  in  most  cases, the Regional Administrator would have

required submission of periodic progress reports on remedial activities and

since  the  supporting  information  must  be available at the facility for

inspection,  the  Agency believes that submission of all documentation will

not be necessary.



    Upon   receipt   of   the   certificate  of  completion,  the  Regional

Administrator  would  determine  whether  the  remedy has been completed in

accordance  with the requirements of proposed Sec. 264.530. If the Regional

Administrator  determines  that  the  applicable  requirements  for  remedy

completion  established  in the permit schedule of compliance have not been

met,  the  Regional  Administrator  would generally notify the permittee of

such a decision and of the steps that must be taken to complete the remedy.

After  such  steps  have  been  taken,  the  permittee  should submit a new

certificate  of  completion  in  accordance  with  the requirements of this

section.



    When  the  Regional  Administrator  has  determined  that the remedy is

complete,  the  permittee  will  be  released  from the financial assurance

requirements for corrective action under Secs. 264.500(c) and 264.526(c).



    The Agency is proposing, in Sec. 264.530(c)(1), that the permit will be

modified according to the Class III procedures for owner/operator-initiated

modifications (Sec. 270.42), to terminate the permit schedule of compliance

when all required corrective action is determined to be complete.



    Generally,  remedies  required  under  subpart  S  will  be  considered

complete only when all measures at a facility have been completed. Thus, if

separate  remedies  are  implemented  for  several units at a facility, all

remedies must be completed before the Agency considers corrective action at

the facility to be complete. For example, if a remedy for releases from two

units  at  a facility is complete, but a different remedy for releases from

three  other  units  at  the  facility  is  incomplete, the Agency will not

consider corrective action for the facility complete.



    In  some situations, however (e.g., where essentially separate remedial

activities  addressing  releases widely separated in location and affecting

different  environmental  media), it may be possible for the owner/operator

to  demonstrate  that  some  portion  of  the remediation required has been

successfully  completed  though  other required actions are still underway.

This  will  usually be the case where the remedy chosen for a facility is a

phased  remedy  divided  under proposed Sec. 264.526(d). In such cases, the

Regional  Administrator  may  allow submission of certifications of partial

completion  of  remedies  by  the owner/operator. Certifications of partial

completion  will  be  handled  in  a  manner analogous to certifications of

partial  closure  and are provided today in proposed Sec. 264.530(d), which

includes  a  provision  for  partial  release  of  the  financial assurance

mechanism as well. However, until all corrective action activities required

in  the permit are complete the owner/operator must continue to comply with

all implementation and reporting requirements specified in the permit which

have not been specifically satisfied to date.



    5.  Determination  of  Technical  Impracticability (Sec. 264.531). This

proposed  section  is  intended  to  address situations where a performance

requirement  set  for a selected remedy in the permit cannot technically be

achieved after reasonable efforts to do so have been made by the permittee.

An example of such a situation might be where hydrogeologic and geochemical

factors  that  were  not  fully  understood at the time of remedy selection

prevent the attainment of a media cleanup standard for ground water



    EPA will require owner/operators to put forth active efforts to achieve

all   requirements  of  the  selected  remedy.  If  the  selected  remedial

technology  proves  not to be capable of attaining a media cleanup standard

or  other  remedy  requirement  (such as a source control measure), EPA may

require  the  owner/operator  to  examine alternative technologies that are

available  and  that  may  be  able  to achieve the requirement. If such an

alternative  technology  is  identified, and is compatible with the overall

remedial  objectives  (e.g.,  would  not  create  unacceptable  cross-media

impacts),  the  permit  will  be  modified to require implementation of the

technology.  (See  discussion of review of remedy implementation under Sec.

264.529.)



    EPA will examine, on a case-by-case basis, the owner/operator's efforts

to achieve remedy requirements. Comments are solicited as to what objective

factors may be examined in making these judgments.

    If  the  Regional  Administrator determines that attainment of a remedy

requirement  is  not technically practicable and no practicable alternative

technologies  are  available,  it  will  be  necessary  to  determine  what

alternative,  or additional, requirements, if any, will be needed to ensure

that  the  remedy adequately protects human health and the environment. If,

for  example,  attainment  of  a  cleanup  standard  for  ground  water  is

determined  to  be  technically  impracticable,  additional measures (e.g.,

facility access controls) to control long-term exposure to the ground water

may  be needed if the ground water is not drinkable. Likewise, if treatment

of  contaminated  soils  to specified levels were not technically feasible,

the  soils  may  need  to be covered or disposed of in a unit with upgraded

engineering  controls  for  release prevention. In some cases, the Regional

Administrator  may determine that no alternative or additional requirements

are necessary. For example, the total risk from the site may be acceptable,

although  some  carcinogenic constituents may exceed the desired risk level

established by the media cleanup standard.



    If  attainment  of  a  media  cleanup  standard  is  determined  to  be

technically  impracticable,  it  is  not the intention of EPA to modify the

standard  to  a  less  stringent  level.  Media cleanup standards represent

levels  that  are  determined  to  be  protective  of  human health and the

environment;  a  finding  that such standards cannot be met does not affect

the  desirability  of  achieving those levels. A determination of technical

impracticability  thus  represents a finding that remediation to protective

levels  cannot  be  accomplished  from a technical standpoint, and that the

owner/operator will not be required to continue to expend resources to meet

the standard.



    A  determination  of  technical  impracticability  does not relieve the

owner/operator  of  his  ultimate  responsibility  to  achieve the specific

remedy  requirement.  If  such  a  determination  is  made,  but subsequent

advances  in  remedial  technology  or  changes  in  site  conditions  make

achievement  of  the  requirement technically practicable, EPA reserves the

authority  to  modify  the permit (if the permit is still in force) or take

other  appropriate  action  to  require attainment of the standard or other

requirement.



I. Interim Measures (Section 264.540)



    This  section  would  establish  the  Agency's  regulatory authority to

compel  permittees  to  conduct  interim  measures.  As part of its overall

strategy  for  implementing  the  corrective action program, EPA intends to

place strong emphasis on using this interim measure {pg 30839} authority to

expeditiously  initiate  cleanup actions, especially in situations where it

is  clear  that  such  a measure will be a necessary component of the final

remedy.  The  need  for  interim  measures  should be assessed early in the

corrective  action  process,  as  well  as  in  subsequent  phases  as more

information on releases and potential remedial solutions become known.



    Under  proposed Sec. 264.540(a), the Agency could require the permittee

to  conduct  interim  measures at a facility whenever the Agency determines

that  a  release  from  a SWMU (or, based on site-specific circumstances, a

threatened  release)  poses  a  threat  to human health or the environment.

Interim  measures will be specified in the schedule of compliance, and will

generally  serve  to  mitigate  actual threats and prevent imminent threats

from  being  realized  while  a  long-term  comprehensive  response  can be

developed.



    Interim  measures  may  encompass a broad range of possible actions. In

some  cases,  such  measures  will  involve  control  of  the source of the

release, while in other cases, control of the contaminated medium, or other

exposure  controls, will be necessary. For example, a permittee responsible

for contamination of a public drinking water supply may be required to make

available  an  alternate  supply  of  drinking water as an interim measure,

until  the  contaminated  surface  or  ground  water  can  be remediated. A

permittee  could  also  be  required,  as an interim measure, to initiate a

ground-water  pump  and  treat  system  to control the further migration of

contamination,  if  it were determined that further significant degradation

of  the  aquifer  would occur while options for the ultimate remedy for the

facility  are  being  studied.  Other  examples of interim measures include

fencing  off  an  area  of  contaminated soils to prevent public access, or

overpacking  of  drums  that  are  in  poor  condition  to prevent possible

leakage.



    The Regional Administrator will consider the immediacy and magnitude of

the  threat  to  human  health  or  the  environment  as primary factors in

determining  whether  an  interim  measure(s)  is  required.  Proposed Sec.

264.540(b)(1)-(9)  lists  factors  which  the  Regional  Administrator  may

consider  in  determining  whether  an  interim  measure is required. These

factors  include:  (1)  The  time required to develop and implement a final

remedy;  (2) actual or potential exposures of nearby populations or animals

to  hazardous  constituents;  (3)  actual  or  potential  contamination  of

drinking water supplies or sensitive ecosystems; (4) further degradation of

the   medium   which   may  occur  if  remedial  action  is  not  initiated

expeditiously;  (5)  presence of hazardous wastes or hazardous constituents

in  drums, barrels, or other bulk storage containers that may pose a threat

of  release; (6) presence of high levels of hazardous constituents in soils

at  or near the surface which may migrate; (7) weather conditions which may

cause   releases   of  hazardous  constituents  or  migration  of  existing

contamination; (8) risks of fire or explosion or the potential for exposure

to  hazardous  constituents  as  a  result  of  an accident or failure of a

container  or  handling system; and, finally, (9) any other situations that

may  pose  threats  to  human  health  or  the  environment.  For  example,

consideration  of  high levels of hazardous constituents in surficial soils

at  a  facility  located  adjacent  to  a  surface  water  body  (see  Sec.

264.540(b)(6))  used  as  a  drinking  water  source  may lead the Regional

Administrator  to  conclude  that  immediate excavation of the contaminated

soil  or  other  containment measures are needed to prevent a threat to the

surface water which could result from runoff after a heavy rain.



    Proposed  Sec.  264.540(c)  would require the Regional Administrator to

notify  the  permittee  in  writing of required interim measures, and would

require  the  permittee  to  initiate  the  interim  measures  as  soon  as

practicable. In some situations, such as an actual emergency situation, the

Regional  Administrator  might  require the interim measure to be initiated

immediately, with little if any formal procedures. More typically, however,

the Regional Administrator will initiate a permit modification under either

Sec.  270.34 or Sec. 270.41 as appropriate, to specify the required interim

measure.  Section  270.41  modification  might  be  used,  for  example, if

installation  of  an  extensive  ground-water  pump  and  treat system were

required.  This  would  be  appropriate  since  such a requirement would be

resource-intensive  for the owner/operator, would likely serve as the basis

for  a final remedial action at the facility during a later decision-making

process  conducted  by the Agency, and would indicate a serious concern for

concentrations  of  contaminants in the ground water about which the public

should  receive  the extensive notice and comment opportunities provided by

that procedure. Conversely, if the interim measure were designed to address

problems  of  lesser  magnitude,  the procedural requirements of the permit

modification proposed today in Sec. 270.34 may be sufficient.



    The proposed regulations in this subsection are similar to those in the

removal  section  of  the  NCP  under  CERCLA (see 40 CFR 300.415). In many

cases,  the  Agency expects that needed interim measures will be undertaken

voluntarily by the owner/operator without the need for permit modification.

In  some  cases,  however, the use of CERCLA removal authorities or Section

7003  of  RCRA may be appropriate; as in a situation where the permittee is

unwilling  to  respond  quickly  to  an  exposure  problem  that  merits an

immediate  response; and where a permit modification to compel the response

would cause unacceptable delay. For example, this would be the case if high

levels  of  constituents  had migrated from the facility and were affecting

nearby  drinking  water  supplies  and  the owner/operator was unwilling to

voluntarily  make  available  an  alternate  source  of  drinking  water to

affected  populations.  The  Agency  would  first  act  to  protect against

potential  exposures, then act to compel the permittee to comply with other

conditions necessary to protect human health and the environment.



    Section  264.540(d)  indicates the Agency's intent for interim measures

taken  at  a facility to be consistent with any further remedy that will be

implemented   at   the   facility   after  full  characterizations  of  the

contamination  under  the  RFI  and  selection  of  the  final remedy under

proposed Sec. 264.525.



    The  Agency  has developed guidance for imposing interim measures under

RCRA.   Interim  Final  RCRA  Corrective  Action  Interim  Measures,  OSWER

Directive 9902.4, May, 1988. Contact: Tracy Back (202) 382-3122.



    As  the  discussion  above  indicates, interim measures are one type of

corrective  measure  which  may  be required under the authority of section

3004(u)   of   RCRA.  In  considering  the  statutory  requirements  for  a

demonstration   of   financial  assurance  by  owner/operators  for  taking

corrective  action,  the  Agency  evaluated several approaches to financial

assurance for interim measures.



    In  many  cases,  a  requirement to demonstrate financial assurance for

interim measures may serve no useful purpose and may actually contribute to

delays  in  facility  cleanups.  For  example,  where an interim measure is

imposed  requiring  removal  of  barrels  containing hazardous constituents

(similar  to  a  removal  action  under  CERCLA) it would be unnecessary to

require  a  demonstration of financial assurance, since compliance would be

relatively inexpensive and could be quickly completed. {pg 30840}



    In  other  cases,  interim  measures  could be relatively extensive and

could  be conducted over a period of several years. This could be the case,

for  example,  where  a  well  system  must be installed to stop a plume of

contamination from further migration at a highly complex site until a final

remedy  could be implemented, or where a soil treatment system is installed

which   would   require  several  years  to  achieve  required  contaminant

concentration levels. In these kinds of cases, a demonstration of financial

assurance   for   interim   measures  will  not  substantially  impact  the

implementation  of the interim measures and would promote the Congressional

intent  of  ensuring  that  adequate  funds  are  available to complete the

required  actions.  In  such a case, requiring a demonstration of financial

assurance  for  an interim measure within 120 days of the imposition of the

interim measure may be reasonable.



    Another  option for addressing the question of financial assurance that

was  considered by the Agency, but was rejected, would have interpreted the

requirement for financial assurance to apply only to final remedial actions

required by the Agency. Still another possible reading of the statute might

lead  to  the  conclusion  that imposition of any type of corrective action

would  require  a full demonstration of financial assurance. The Agency has

concluded  that the objective of the corrective action provisions, which is

to  remediate  environmental  problems  in  an  expeditious  manner and the

financial assurance objective of ensuring adequate funding for remediation,

should be balanced on a case-by-case basis for interim measures. The Agency

specifically solicits comments on this approach.



J. Management of Wastes (Sections 264.550-264.552)



    1.   Overview.   In   the   course   of   corrective  action,  facility

owner/operators  will  manage a wide range of wastes, including both wastes

that  meet  the  RCRA  definition of hazardous waste and those that do not.

Sections  264.550-264.552  of  the  proposed  regulations  would  establish

standards  for  the  management  of  these wastes during corrective action.

Under  these  sections,  wastes that meet the RCRA regulatory definition of

hazardous waste must be managed in accordance with the applicable standards

of  40  CFR  parts  262,  264,  268,  and 269, with certain exceptions (see

following  discussion  of  temporary  units).  In  addition, statutory land

disposal  restrictions  will  be triggered when restricted hazardous wastes

are  placed  into a land disposal unit, and minimum technology requirements

will  apply  to new or replacement units and lateral expansions of existing

units.  Finally,  non-hazardous  solid  waste  must be handled according to

applicable  subtitle  D  standards, except where the Regional Administrator

determines  that  additional controls are necessary to protect human health

and the environment.



    In  general,  owner/operators  will  also have to comply with all other

applicable  Federal, state, and local regulations. The basic responsibility

for  complying  with  any  applicable  permits and requirements will be the

owner/operator's;  however,  the  EPA  or State permit writer will consider

these requirements in selecting a remedy and will take steps to ensure that

remedies selected are consistent with other Federal or State standards.



    2.   General  Performance  Standard  (Sec.  264.550).  Section  264.550

proposes a general performance standard for management of all wastes during

corrective  action.  Under  this  standard,  the Regional Administrator may

impose  any  requirements on the management of corrective action waste that

s/he  deems  necessary  to  protect  human health and the environment. This

standard  applies  both  to solid and to hazardous waste managed as part of

RCRA corrective action requirements. This general standard derives from the

statutory  mandate  of  section  3004(u) to require corrective action; as a

corollary  to  this  authority,  the  Agency  is  authorized to ensure that

actions  taken  to  implement  corrective  actions  do  not themselves pose

unacceptable  threats.  EPA  is  therefore  obligated to impose controls on

management  of  wastes,  pursuant  to  remedial activities, as necessary to

protect human health and the environment.



    EPA  believes  this  general  performance standard is necessary because

current  regulations governing treatment, storage, and disposal of solid or

hazardous wastes may not be adequate in all situations involving corrective

action.  In  particular,  many  cleanup  activities  that  do  not  involve

treatment,  storage, or disposal of hazardous waste require special care to

prevent release of hazardous constituents. For example, dredging of surface

impoundments  or  excavation of soils containing volatile organics can lead

to  significant  releases of hazardous constituents to the air, potentially

endangering  workers  or neighboring populations. When such situations have

arisen   in   Superfund  actions,  EPA  has  imposed  controls  on  cleanup

activities,  such  as  prohibiting  cleanup  when the wind was blowing in a

certain direction or requiring air monitoring and the cessation of activity

when  a  specific level was exceeded. Requirements to control air emissions

from RCRA permitted units, when promulgated, may not be strictly applicable

to  certain  SWMUs.  Proposed  Sec. 264.550 would give EPA the authority to

impose  such  conditions,  or  other controls, as part of correction action

under section 3004(u).



    Section  264.550  proposes general performance standards for management

of  all  wastes  during  corrective action. Under proposed Sec. 264.550(a),

wastes  must be managed in a way that is protective of human health and the

environment  and  that  complies  with applicable Federal, State, and local

regulations.  Facility  owner/operators will be required to comply with all

applicable  regulations  in  carrying  out corrective action; proposed Sec.

264.550(a)(2)  codifies  this  requirement as a reminder to owner/operators

that  RCRA corrective action permit conditions do not absolve them of other

legal responsibilities.



    However,  there  may  be  cases where a State or local law stands as an

obstacle  to  the  accomplishment  of Congress' purpose in enacting section

3004(u),  or  directly  conflicts  with regulations developed under section

3004(u).  EPA  believes  that  in such rare cases where State or local laws

could  be said to frustrate the purposes of the statute, a court might find

such  laws  to  be  preempted by RCRA. See, e.g. ENSCO, Inc. vs. Dumas, 807

F.2d.745 (8th Cir. 1986). Alternatively, in the case of a State requirement

that  could  jeopardize  implementation of a remedy, it may be possible for

the State to waive that requirement.

    3.  Management  of  Hazardous  Wastes (Sec. 264.551(a)). In many cases,

waste  subject  to corrective action will meet the regulatory definition of

RCRA hazardous waste. A facility owner/operator would be handling hazardous

waste  at  a  SWMU,  for  example, if it contains listed wastes disposed of

before November 19, 1980, or the wastes fail the characteristic test. Also,

releases  from  hazardous  waste  management units exempted from permitting

requirements,  such  as  wastewater  treatment units or 90-day accumulation

tanks,  may  be  hazardous  waste  even  though the units in which they are

managed  are  exempt  from  permitting.  Similarly,  soils and ground water

contaminated  with  releases  of  listed  hazardous waste will generally be

subject  to  subtitle  C  standards.  Under  {pg  30841}  current  rules, a

contaminated  medium that exhibits any of the characteristics identified in

subpart C of part 261 or contains a listed hazardous waste, including (with

certain  exceptions)  any  constituent  generated  by a listed waste (e.g.,

leachate),  must  be managed as hazardous waste until it no longer contains

any  of  the  waste, is delisted, or for characteristic wastes, until it no

longer  exhibits  any of the characteristics. Where wastes meeting the RCRA

regulatory  definition of ''hazardous'' are treated, stored, or disposed of

during  corrective  action,  they will be subject (with certain exceptions;

see  discussion  below)  to the standards of 40 CFR parts 262, 264, and 268

(or, in the case of air emissions, part 269 or the Clean Air Act). Proposed

Sec. 264.551(a) clarifies this point.

    Proposed  Sec.  264.551(a),  however,  would  also  allow  the Regional

Administrator  discretion  to waive most procedural requirements associated

with  closure of hazardous waste management units (subpart G of 40 CFR part

264)  for  units  created  for  the  purpose  of managing corrective action

wastes.  Procedural  requirements that may be waived include submission and

approval  of  closure  plans,  and  specific time frames for submission and

review of the plan and other activities associated with closure.



    EPA  believes that the process for developing and reviewing remedies as

outlined  in  today's  proposal,  coupled  with the procedures that will be

followed  in  modifying permits to specify remedies, provides an equivalent

and  equally  effective  means  of ensuring that the applicable closure and

post- closure technical requirements are required of units that are created

and  operated  for the purpose of implementing remedies. Were the subpart G

procedural  requirements  to  remain  applicable to those units, the result

would  be  to  have  two parallel, and essentially redundant (and sometimes

inconsistent),   processes  for  establishing  technical  requirements  for

remedial  units.  It  should  be  understood,  however,  that  the  general

performance  standard for closure (see Sec. 264 111), and the unit-specific

technical closure standards could not be waived, and will be applied to new

units created during the remedy.

    Waiver of the subpart G procedures is at the discretion of the Regional

Administrator.  In  some  situations it would be appropriate to require the

owner/operator to follow the subpart G process for closure/post-closure for

a  unit  used  in  remediation activities. An example could be where a unit

(such   as  a  tank)  is  constructed  and  operated  for  the  purpose  of

implementing   the   remedy   for  the  facility,  but  the  owner/operator

subsequently  chooses  to  continue  to  use  the  tank  after the remedial

activity is completed, for other hazardous waste management purposes. Since

the  tank  would  no longer be part of the remedy, the owner/operator would

have  the  obligation  to  follow  the normal administrative procedures for

closure of the tank.



    a.  Temporary  Units  (Sec.  264.551(b)).  EPA  is  concerned that some

technical  requirements for units prescribed in the current 40 CFR part 264

regulations  may  be inappropriate for management of hazardous waste during

corrective action, and may in fact discourage prompt cleanup. The Superfund

program has frequently found it necessary to build temporary units to store

wastes  for  short  periods  of time before treatment or final disposal. In

many  cases, the Agency has found that full RCRA 40 CFR part 264 regulatory

standards  may  not  be  necessary for such short-term storage taking place

during  the  course of remedy implementation, and that full compliance with

these standards could in fact delay cleanup. For example, for some remedies

it  will  be necessary to excavate soils contaminated with hazardous wastes

and  store  them  in  a  pile for a short time (e.g., a few days or weeks),

prior  to treatment. Under current RCRA regulations, the pile would have to

comply  with  the  part 264 requirements applicable to waste piles, such as

minimum  technology  liner requirements, ground-water monitoring, and other

operating  and  maintenance  requirements.  As  another example, tanks will

often be used for short-term storage of hazardous wastes in the course of a

remedy;  such  tanks  would  accordingly be required to have full secondary

containment.  EPA believes that in many cases applying these stringent part

264  standards,  which  are  designed  to  ensure  adequate  protection for

long-term   management   of  hazardous  wastes  in  such  units,  would  be

unnecessary  from  a  technical standpoint, as well as counterproductive in

many  cases.  In  the  above  example of the temporary pile, a single liner

might be adequate, with some limited monitoring, depending on the nature of

the  wastes,  the  environmental  setting, and other factors. Requiring the

pile to meet full part 264 standards would result in delays in constructing

the pile, and increased expense to the owner/operator which could otherwise

be   directed   to  other  remedial  work,  without  appreciably  increased

environmental   benefits.  Note  that  adjustments  to  minimum  technology

standards  applicable  to the pile would have to be done in accordance with

certain statutory requirements (see following discussion).

    Proposed  Sec.  264.551(b)(1)  provides  EPA authority to modify 40 CFR

part  264  regulatory design, operating, or closure standards for temporary

units, as long as alternative standards that are protective of human health

and  the environment and comply with statutory requirements are imposed. In

the  case of temporary tanks, for example, the Regional Administrator would

be  making a determination generally analogous to risk-based variances from

secondary  containment  requirements  for  tanks  in  Secs.  264.193(g) and

265.193(g).



    The  Agency  believes  that  this approach to temporary units; that is,

adjusting  design and operating standards for such units on a site-specific

basis,  is  sensible  and  practical  within  the context of the corrective

action  process.  The  process of examining and selecting corrective action

remedies  will  involve  a  high  degree  of Agency oversight, and remedial

decisions  will  be  made  in  consideration  of  a number of site-specific

factors.  Since  remedies  can  be  tailored to site-specific conditions, a

degree  of protection of human health and the environment equivalent to the

generic   national  standards  can  be  achieved,  while  facilitating  the

timeliness and implementability of the remedies.



    This  provision for temporary units could apply to any unit used during

corrective action, except incinerators and non-tank thermal treatment units

(e.g., pyrolysis units). EPA believes that modifications of 40 CFR part 264

design  standards  should  not  be  allowed  for  incinerators and non-tank

thermal  treatment units because of the complexity of these devices and the

high  level  of  public  concern  about  their  operation. Furthermore, the

Regional  Administrator  would  be  authorized  to  modify  only  technical

standards  for  temporary  units  under  this  authority,  not  performance

standards.  For  example, secondary containment for tanks might be modified

in  specific  situations;  however, basic performance standards relating to

releases  to  the  environment- such as performance standards in the 40 CFR

part 269 air emissions regulations-could not be modified.



    It  should be understood that under this provision for temporary units,

only  requirements  applied  solely  by  regulation,  and  not  directly by

statute,  may  be  modified. Statutory requirements may be modified only to

the extent authorized by statute. {pg 30842}



    Two  statutory  requirements  in  particular may often be applicable to

temporary  units,  specifically, the land disposal restriction requirements

of RCRA section 3004(d)-(g) and 40 CFR part 268, and the minimum technology

requirements of section 3004(o). However, the Agency expects that temporary

units  may  often be able to meet the statutory provisions for waivers from

these   requirements  under  section  3004(g)(5)  (for  the  land  disposal

restrictions),    and    section   3004(o)(2)   (for   minimum   technology

requirements).  The major permit modification associated with the selection

of  remedy  would  provide the public notice and comment usually associated

with  a petition submitted by the owner/operator (a waiver of land disposal

restriction  requirements  would, however, also be published in the Federal

Register,  as required by RCRA section 3004(i)). In addition, the statement

of  basis  associated  with the permit modification will summarize, and the

supporting  Administrative  Record  will  provide, the documentation of the

Agency's  finding  that  the statutory requirements for granting the waiver

have been met.



    The Agency believes that waivers from these statutory requirements will

often  be  appropriate  for  temporary units, and in some cases may also be

essential  to  the prompt implementation of corrective action. For example,

in  many cases it will be necessary to place wastes temporarily on the land

beside  a  hazardous  waste  unit  when  that unit is being excavated; this

placement  would be an interim step before incineration or other treatment.

It has been EPA's experience in Superfund that full compliance with minimum

technology  requirements (i.e., double liners, leachate collection systems,

and  ground-water  monitoring)  in  such  cases  may often be unnecessarily

restrictive  and  could  delay  cleanup.  Instead,  in  cases of short-term

storage,  something  less  than  minimum  technology-for  example, a single

rather  than  double  liner-  could frequently be fully protective of human

health and the environment. The Regional Administrator could require design

standards  less stringent than the full minimum technology requirements, so

long  as they would ensure (consistent with the waiver provision of section

3004(o)(2))  that the controls will be of an equivalent level of protection

for the life of the unit.



    Similarly,  the  application  of  land  disposal  restrictions  to  the

temporary  placement of waste could impede corrective action in some cases.

If  the  restrictions applied it would be impossible to store wastes on the

ground  while they awaited treatment, because placement on the ground could

not  occur before the treatment. The only alternative would be to leave the

waste  untreated  in place, or to store it in tanks or containers, which in

some  cases  might  cause  a  delay and add to the complexity of the remedy

without  serving  public health or the environment. In such cases, it would

be  necessary  to  demonstrate  that  the  petition  standards for the land

disposal  ban  have  been met, so that such temporary placement on the land

would be allowed.



    In  modifying  40  CFR  part  264  and  part  269  design  or operating

regulatory  standards,  and  in  establishing  alternative  standards,  the

Regional  Administrator  would  be required to consider a range of factors,

which  are  listed in proposed Sec. 264.551(b)(2). These include the length

of  time the unit will be in operation, the type of unit, the potential for

releases  from  the  unit,  the  type  of  waste, hydrogeological and other

conditions  at  the facility, and the potential for human and environmental

exposure  to  releases  if they did occur. The Regional Administrator would

specify in the permit design and operating requirements that would apply to

the temporary unit and the length of time it could remain in operation, and

requirements associated with its closure. These conditions would be subject

to  public notice and comment as part of the process for approval of remedy

selection.



    Today's  proposal  specifies  a  time  limit  of 180 days for temporary

units.  This  time  period  is  consistent  with  the  closure period for a

hazardous  waste unit and the ''temporary authorization'' period in the new

permit  modification rule. It is expected that many temporary units will be

needed  for much shorter periods of time; however, EPA also recognizes that

in  some  cases a temporary unit might have to remain in service beyond the

180-day  limit,  due  to  unexpected  circumstances. For example, if wastes

being  stored in a temporary unit were to be taken to an off-site facility,

and that facility no longer had the capacity or was unwilling to accept the

waste, it might be advisable to continue storing the waste in the temporary

unit  for  a  limited  amount  of  time (e.g., 30 days). In such cases, the

facility  owner/operator  could  request  an  extension.  Requests for such

extensions  would  typically  be  processed as a Class I modification, with

Regional  Administrator  approval,  under permit modification procedures of

Sec.  270.42.  Such  time  extensions  for  temporary  units  would only be

approved  where  it  is  necessary  because  of  unforeseen, temporary, and

uncontrolled circumstances, and when the owner/operator is actively seeking

alternatives  to continued use of the unit(s). If the owner/operator failed

to  move  expeditiously  to  remove the unit, the Agency would deny further

extensions  and require the owner/operator to retrofit the unit to meet all

applicable  Subtitle  C design and operating standards, or remove the waste

and close the unit.



    EPA  considered  several  alternatives  in  specifying  time limits for

temporary  units.  One alternative would have been to not specify a generic

time  limit  for  temporary  units  in  the  rule,  and  allow the Regional

Administrator  to  set  permit  conditions  limiting  the  active life of a

temporary  unit  on  a case- specific basis. This approach would allow more

flexibility  in designating such units, recognizing that the amount of time

a  temporary  unit  could  safely remain in service may vary significantly,

depending  on  the  type  of  unit,  type of waste, unit location and other

factors.  Another approach could have been to specify a shorter time limit,

such  as  90 days, which would be consistent with the provision for on-site

accumulation  of  wastes  by  generators  (Sec.  262.34).  Alternatively, a

specified  time  period longer than 180 days (e.g., one year) for temporary

units  might also be appropriate. EPA specifically requests comments on its

approach  to  temporary  units, including suggestions for how ''temporary''

should be defined.



    Today's  proposal (Sec. 264.551(b)(2)(ii)) also clarifies that off-site

units  (i.e.,  that  are located outside the facility property) will not be

treated as ''temporary units'' for the purpose of managing hazardous wastes

generated as part of a remedy or interim measure.



    In  addition, proposed Sec. 264.551(b)(2)(iii) specifies that temporary

units  may  only  be used for treatment or storage of wastes that originate

within the facility boundary. This would preclude, for example, wastes from

a  different  facility  from  being  brought to a temporary unit at another

facility  for storage or treatment. However, wastes that were released from

solid  waste  management  units  at  the  facility,  and  that subsequently

migrated  beyond the facility property, could be recovered and managed in a

temporary  unit  in  the  context  of  implementing  a  remedy.  Comment is

solicited on these limitations to the temporary unit concept.



    b.  Corrective Action Management Units (Sec. 264.551(c); Sec. 264.501).

In many cases, corrective action at RCRA {pg 30843} facilities will address

broad  areas  of  contamination,  which  may  or may not themselves contain

discrete waste management units. For example, soils surrounding one or more

leaking  surface  impoundments, landfills, or tanks may be contaminated. In

devising a remedy to address this situation the facility owner/operator, at

the  direction  of EPA, could consider the contaminated area as a whole and

select  a  remedy  that best addressed the entire area of contamination. In

these  situations,  EPA  believes that the entire area of contamination can

properly   be  considered  a  waste  management  ''unit''  under  the  RCRA

regulatory  structure.  Consequently,  proposed  Sec.  264.551(c) gives the

Regional  Administrator the authority to designate such areas as corrective

action management units (CAMUs).



    As  indicated  in proposed Secs. 264.551(c) (1) and (2), designation of

such  an  area  as a waste management unit will have important implications

for  the  management  of  hazardous  waste  within that area. Specifically,

movement  or  consolidation of hazardous wastes within these areas will not

automatically  trigger  the  statutory land disposal restrictions (sections

3004(d)-(g))  or  minimum  technology  requirements (section 3004(o)). Land

disposal restrictions are triggered by placement of a restricted waste in a

waste  management  unit  (section 3004(k)); minimum technology requirements

are triggered by the creation of new or replacement surface impoundments or

landfills,  or  lateral  expansions  of  existing  surface  impoundments or

landfills  (section  3004(o)(1)). Consequently, if an area of contamination

is  designated  as  a unit by EPA during corrective action, hazardous waste

moved  within  the unit would not be subject to land disposal restrictions.

Similarly,  moving  hazardous  wastes  around  inside  the  unit  will  not

constitute  either  creation  of  a  new  or replacement unit, or a lateral

expansion  of  an existing unit; therefore the minimum technology standards

would not apply.



    EPA  believes that this approach to defining ''unit'' in the context of

corrective  action  is  essential to the implementation of sections 3004(u)

and  3008(h)  of  RCRA,  and  that  it accurately reflects the realities of

cleanup  activities.  In addressing a broad area of contamination, EPA or a

facility  owner/operator  requires  the flexibility to move hazardous waste

around   and   consolidate  it  without  automatically  triggering  minimum

technology  or treatment requirements at every turn. For example, a typical

remedy  at a corrective action sight might consist of treatment of the most

highly  contaminated soil at an off-site incinerator, together with on-site

consolidation   and   capping   of   remaining  soil  containing  hazardous

constituents  at low concentrations. Incineration or other treatment of the

less  contaminated  soil might yield few, if any, benefits, and it might in

some  cases  delay  cleanup  and increase risk; for example, risk resulting

from   transportation   of   wastes.  However,  in  moving  the  soils  for

consolidation,  a  narrow  application  of land disposal restrictions might

require incineration (or other treatment) of the soil and prohibit the most

straightforward,  implementable, and, in some cases, most effective remedy.

Similarly,  imposition  of  minimum technology requirements will add to the

cost  of  cleanups  and may, in some cases, cause delays in implementation,

without providing any significant environmental benefit.



    EPA  believes that its general approach to the definition of unit makes

sense  not  only  within  the context of section 3004(u) but also for other

remedial  action  involving  waste  already in place-such as source control

taken  in  the  course  of a final cleanup of a unit which will not receive

waste  in  the future. Where remedial action is taking place within an area

that  has already been contaminated, there should be sufficient flexibility

to  select  effective remedies that can be safely and reliably implemented.

In  cleaning  up existing contamination problems, EPA believes that it will

often  be  unnecessary  and  counterproductive to strictly apply to cleanup

activities  standards  that  were  designed  to  prevent  future  risks  at

operating  facilities  that  will  continue to receive and manage hazardous

waste.



    In  Sec.  264.501,  EPA is today proposing a definition of ''corrective

action management unit,'' which is intended to clarify the nature and scope

of  the  areas  which  may  be given this designation. The definition is as

follows:



    ''   an   area   within  a  facility  as  designated  by  the  Regional

Administrator   for   the   purpose   of   implementing  corrective  action

requirements  of  this  subpart, which is broadly contaminated by hazardous

wastes  (including hazardous constituents), and which may contain discrete,

engineered land based sub-units.''



    This  definition is intended to place several important restrictions on

how  CAMUs  are  designated,  and  on  how hazardous wastes must be managed

within  CAMUs.  It  should first be recognized that it will be the Agency's

(or  State's)  role  to  define  the  areal  configuration of any CAMU at a

facility. This decision should be made based upon careful assessment of the

extent  of  the  contamination  of  soils, location of existing solid waste

management  units,  the  remedial  objectives  for  the facility, and other

relevant  factors.  Although owner/operators may wish to propose a specific

area  as a CAMU, the decision as to whether designating a CAMU is necessary

and  appropriate to implementing a remedy, and if so, the boundaries of the

unit, must rest with the Agency or the State.

    In   designating   CAMUs,   only  areas  where  contaminated  soils  or

concentrated  wastes  already  exist  will  be  included. Uncontaminated or

''virgin''  areas of a facility cannot be included within a CAMU. Likewise,

two  separate  areas  of contamination could not be combined into one CAMU,

since they could not be considered a single unit.



    In   some   cases,   remedial   solutions   may  involve  creating  new

''sub-units,''  or  enlarging  existing  ones  within  a CAMU. For example,

dispersed,  low-  level  contaminated  soils  might  be consolidated into a

smaller,  discrete  landfill which would then be capped. Similarly, in some

cases an effective remedial approach could be to remove wastes from several

small landfills within a broad area of contamination, stage them in a waste

pile prior to treatment, and dispose of the residuals in a newly engineered

''sub-unit.''  Thus, it is intended that CAMUs may include one or more land

based  sub-units created or expanded as part of the cleanup action, as well

as pre-existing solid waste management units.



    In  specifying  that  a  CAMU  may  contain  land-based  sub-units, the

proposed  definition is meant to clarify that non-land based units, such as

a  tank  or an incinerator, would not be considered part of the CAMU. Thus,

while  a  remedy  might  involve  constructing  a tank treatment system for

contaminated materials within the area defined as the CAMU, the tanks would

be  subject  to  all  applicable  part  264  standards  for  tanks, and the

residuals  from  the  treatment  systems  would  also  be  subject  to  any

regulatory or statutory requirements that would apply had the CAMU not been

designated.



    The  Agency believes that allowing the creation of land based sub-units

within {pg 30844} a CAMU is reasonable and necessary to realizing the basic

objective  of  the  CAMU concept; i.e., allowing sensible cleanup solutions

for  existing  contamination problems. In essence, a CAMU can be considered

to  be  a  large,  land-  based  unit. Remedial actions such as treating or

consolidating  wastes,  or  creating  new land-based units within the CAMU,

serve  in  effect to enhance the environmental performance and integrity of

the unit.



    In  developing  the  concept  of  the  CAMU  as  articulated in today's

proposal,  the Agency considered several alternative approaches. One option

would  have  been  to  only allow movement of wastes into existing landfill

areas within the CAMU; new land-based units would not be considered as part

of  the  CAMU.  This option could have caused land disposal ban and minimum

technology   requirements  to  be  triggered  relatively  frequently,  thus

restricting  decision  makers'  flexibility  to  upgrade these areas of the

CAMU,  and engineer more effective and protective waste management systems.

In  addition,  the  option  would likely create substantial difficulties in

defining   what   constituted   new  units  within  the  area  of  existing

contamination.



    EPA also considered options that would have significantly broadened the

CAMU  concept.  Once such option would have allowed wastes to be excavated,

treated  in  a  non land-based unit (e.g., a tank) within the CAMU, and the

residuals redeposited on the land without triggering the land disposal ban.

A  variation  of  this  approach  would also allow an incineration or other

thermal  treatment system to be considered as part of the CAMU. Yet another

option  considered  would  have  allowed CAMUs to include land areas at the

facility  that were not already contaminated; such areas might thus be used

as  sites  for  locating  new  landfills. Although these options would have

offered  more  flexibility in designing remedies, the Agency has chosen not

to  propose  such  broader interpretations of the CAMU concept, for several

reasons. Allowing uncontaminated land to be included as part of a CAMU (and

thus   potentially   allowing   it   to  become  contaminated)  would  have

contradicted  the  overall intent of the CAMU; that is achieving reasonable

cleanup   solutions  for  existing  contamination  problems.  In  addition,

allowing  non land- based units to be considered part of the CAMU would, in

effect,  contradict  the  notion  of  the CAMU as a type of land-based unit

(albeit  one  that  is contaminated and needs to be upgraded to improve its

protectiveness),  and  could  have  complicated  the  ability to impose the

stringent part 264 standards for treatment units such as incinerators.



    It  should be understood that, given today's proposed definition or any

of   the   alternative  approaches  described  above,  several  fundamental

requirements  will apply to CAMUs. Firstly, land disposal restrictions will

apply  whenever  hazardous  waste  is  placed  into a CAMU from outside its

defined area. In addition, all waste management activities conducted within

the  CAMU  will  be  protective  of  human health and the environment, will

conform  to  the  standards  for  remedies  proposed in Sec. 264.525(a), be

evaluated  in  terms  of  the  remedy  selection  factors  of proposed Sec.

264.525(b),  and  comply  with  the  cleanup  standards  of  proposed  Sec.

264.525(d).  Finally,  all  decisions  regarding the scope of CAMUs and the

nature  of  remedial  activities that will be conducted within them will be

subject to public review and comment during the remedy selection and permit

modification process.



    EPA  specifically  invites  comment  on  today's  proposed  approach to

defining  CAMUs,  and  any  alternative  approaches  which may be viable in

achieving the remedial goals for which it is intended.



    Proposed  Sec.  264.551(c)(4)  lists  the  factors  which  the Regional

Administrator  will  consider in specifying closure requirements for CAMUs.

As  with  other  units  created  for the purpose of implementing corrective

action  remedies.  EPA  proposes to not apply part 264 subpart G procedural

requirements  for  closure  to CAMUs (see previous discussion on closure of

remedial  units),  in  favor  of  using  the  remedy  selection  and permit

modification  process  that  will  serve  to  establish comprehensively the

technical requirements for the remedy. In addition, under today's proposal,

the  specific  technical standards for closure and post-closure (e.g., type

of  cap,  scope  of post-closure ground-water monitoring) of CAMUs would be

determined   through   the   corrective  action  process  rather  than  the

unit-specific technical closure standards of part 264.



    Technical   requirements   for   closure  and  post-closure  of  CAMUs,

therefore,  will  be  established  on  a  site-specific basis. The specific

requirements  for CAMU closure/post-closure must be designed to achieve the

general  performance  standard  of  Sec.  264.551(c)(5).  This  standard is

essentially  the  same as the performance standard for closure in subpart G

(see  Sec.  264.111).  In  addition  to this general standard, the Regional

Administrator will use the decision factors specified in Sec. 264.551(c)(4)

in  determining the specific closure and post-closure requirements that are

appropriate for the CAMU to ensure that the general performance standard is

met.  These  decision factors will include considerations of waste and unit

and environmental characteristics, as well as the potential for exposure to

contaminants should future releases occur.



    This  approach  to  determining  closure/post-closure  requirements for

CAMUs  is  intended  to  provide  flexibility  for the regulatory Agency in

setting  appropriate  standards specific to the site conditions, while also

ensuring  that  adequate  long-term  controls  are  imposed  for any wastes

remaining  within  the  CAMU.  This  approach  is  also consistent with the

general  process  for  defining  remedies  and  for management of wastes as

established in proposed Secs. 264.525 and 264.550-552.



    EPA  considered  other  approaches for prescribing closure/post-closure

requirements for CAMUs. One approach would have been to adopt a set of more

specific  requirements that would be applied generically to all CAMUs. This

approach  would  have  been  similar  to  the  current RCRA regulations for

closure/post-closure  of conventional hazardous waste units (e.g., tanks or

waste  piles). This approach was rejected, however, for two reasons. First,

the closure requirements for hazardous waste units are designed to apply to

discrete,  engineered  units that must also comply with specific design and

operating standards under RCRA. In contrast, CAMUs will typically be broad,

contaminated  areas that may contain discrete or non-discrete ''sub units''

of  varying  types and configurations. It would therefore be impractical to

specify  generic  national  standards  for a class of units that will be of

such  diversity,  and  within  which  it will make sense to apply different

closure techniques to different areas or sub-units of the CAMU.



    The second reason for not applying generic national standard to closure

of  CAMUs  relates  to  the  nature of the corrective action process. Under

corrective  action,  the Agency has considerable control over the technical

decision-making  process,  and cleanup problems at facilities are typically

subjected  to  direct Agency review and oversight. In contrast, the closure

process under RCRA typically involves review and approval of owner/operator

plans  against  established  regulatory  standards.  EPA  believes that the

greater  control over technical decisions that is provided under corrective

action  allows a more site-specific tailoring of closure requirements based

on a thorough knowledge of site conditions.



    4.  Management  of  Non-Hazardous Solid Wastes (Sec. 264.552). In other

cases,  wastes addressed under corrective action will not meet the specific

RCRA definition of hazardous waste. Many {pg 30845} wastes that do not meet

the   RCRA  regulatory  definition  of  hazardous  wastes  contain  varying

concentrations  of  hazardous constituents that, if the waste is improperly

disposed  of,  could  be  released to ground water, surface water, soil, or

air.  The  goal  of  corrective  action  is to protect human health and the

environment  by  removing  these  contaminants  from  the  environment, and

controlling  the  source  of  the  release-even if the waste from which the

release originated does not meet the regulatory definition of hazardous.



    Proposed  Sec.  264.552 states that non-hazardous wastes handled during

corrective  action  must  be  handled  in  accordance  with  any applicable

subtitle  D  standards.  The  Agency  is  in the process of developing more

comprehensive regulations under subtitle D, and will continue to examine in

that  context  issues relating to the applicability of those regulations to

the  management of solid wastes undertaken as part of subtitle C corrective

actions.



    In   addition,   the   proposal  provides  the  Regional  Administrator

authority,  under certain circumstances, to impose more stringent standards

than  subtitle  D.  For  example,  a  specific waste might not be listed as

hazardous,  but  it  might  have a high concentration of specific hazardous

constituents,  or  it might be similar in composition to a listed waste. In

such cases, the Regional Administrator could impose subtitle C standards or

standards  that  were  protective  given  the circumstances at the site and

characteristics  of  the  waste where necessary to protect human health and

the  environment  even  though  the  waste  did  not  technically  meet the

definition of hazardous waste.

K. Required Notices (Section 264.560)



    1. Notification of Ground-Water Contamination. Proposed Sec. 264.560(a)

would require the permittee to notify EPA and any persons who own or reside

on  land  adjacent  to  the  facility  in  writing within 15 days when s/he

discovers  that  hazardous  constituents  originating  from  a  SWMU at the

facility  have migrated beyond the facility boundary in concentrations that

exceed action levels.



    Action levels are defined in proposed Sec. 264.521 of today's proposal,

and  are  discussed  in detail in section VI.E of this preamble; therefore,

they are not discussed in detail here. However, the reader should note that

action  levels  are  established  using conservative assumptions to protect

human  health  and  the environment. Concentrations exceeding action levels

will  not  necessarily  result  in adverse effects. Short term exposures to

releases  above  action  levels  may  often not represent a threat to human

health  or  the environment since action levels are derived using long-term

exposure  assumptions.  In  fact,  in  some  cases constituents at or above

action levels will not ultimately require active remediation.



    This  notification  requirement  is  limited to situations in which the

adjacent  land  can  reasonably  be  determined to overlie the contaminated

ground  water  given  current  knowledge  of  the direction and rate of the

ground- water flow.



    EPA  believes  that  it  is appropriate to require such notification in

order  to  provide  adequate  awareness  for  persons who are, or who could

potentially  be  exposed  to  the contaminated ground water. It is possible

that  residents  near  a facility could be using water from wells that have

become  contaminated from the facility; in such cases, prompt notice to the

individual would be an essential part of the response action.



    The  Agency may require the permittee to initiate an interim measure to

address  off-site  ground-water  releases  virtually immediately, including

making  available  an alternative drinking water supply when drinking water

supplies  have  become  contaminated.  On  the  other  hand, the Agency may

ultimately  decide,  based on further study, that no further action will be

necessary.  Such might be the case where the ground water is highly saline,

and  not  usable  for  drinking. As explained earlier in this preamble, the

actual response action that may be required when ground-water contamination

is  identified will be determined by a variety of site-specific factors. In

any case, an early notification that an action level has been exceeded will

alert  the  adjacent  resident  or  owner to the potential problem and will

allow  their  informed  comment  on further permitting actions taken at the

facility  if  they  have  special concerns. EPA solicits comment as to what

alternative  mechanisms  or approaches could or should be required to alert

potential  users  of  ground  water  that contamination has occurred from a

facility.



    2.  Notification  of  Air Contamination. Proposed Sec. 264.560(b) would

require the permittee to notify, in writing, EPA and any residents or other

individuals  who  may  be  exposed to air emissions from SWMUs above action

levels.  This  proposed  notification requirement would apply when there is

exposure  in  a  residential  setting,  or  other situation where long-term

exposure  to the air emissions from the facility can reasonably be assumed.

This  is  consistent with the overall approach to corrective action for air

releases (as discussed in section VI.E of this preamble).



    This  notification  requirement  for  air  would also be triggered when

residences  or  activities that could result in long- term exposures become

established near the facility after the initial release investigations have

been  conducted  and are within an area where air emissions have been found

to  exceed  action  levels.  Permittees  whose remedial investigations have

confirmed  substantial air emissions migrating beyond their property limits

have  a  continuing  responsibility to identify and provide notice whenever

such exposure situations occur. If concentrations of hazardous constituents

in air beyond the facility boundary are found to be causing actual exposure

problems  of concern, the Regional Administrator may require the permittee,

in  addition  to the notice requirement, to institute an interim measure to

reduce  the  threat.  For example, s/he could require the installation of a

floating  cover  on  a  surface impoundment for the purpose of reducing the

surface  area of the impoundment available to allow the escape of hazardous

constituents  to  air.  In many cases the release to air will be reduced or

eliminated  during  the  course of remedial activities at the facility. For

example, a permittee may be required to excavate and treat wastes contained

in the SWMU or to cover the SWMU with a cap.



    EPA  solicits  comments  on  what  alternative mechanisms or approaches

could or should be required to alert persons who may be exposed by releases

of hazardous constituents into the air from RCRA facilities.



    3.   Notification  of  Residual  Contamination.  Under  the  regulatory

authority  proposed  in  Sec.  264.560(c),  the  Regional Administrator may

require   the   permittee  to  provide  notice  whenever  hazardous  wastes

(including  hazardous  constituents) are left in place in the subsurface at

the  facility.  This  requirement  would  apply whether hazardous wastes or

hazardous  constituents  left in the subsurface are contained in a discrete

unit or diffused throughout subsurface soils. The notice would consist of a

notation  in  the deed to the facility property, or a notification via some

other  instrument used by the State if the instrument is routinely searched

during the course of transferring ownership of property. When such a notice

is  required,  the  notice must clearly indicate the types, concentrations,

and  locations of hazardous wastes or hazardous constituents that remain at

the property. {pg 30846}



    EPA  believes  that  the Agency's authority to allow owner/operators to

certify completion of their corrective action responsibilities and, in some

cases,  close  or transfer ownership of the property while hazardous wastes

remain  in  place  in  the subsurface is accompanied by a responsibility to

ensure that future owners of the property do not inadvertently act in a way

that  could result in harmful exposures to the residual contamination. This

could  occur, for example, when a facility in an area where mixed land uses

are  common  (e.g.,  residential  and  light  industrial uses) is closed in

accordance  with  applicable  regulations  and ownership of the property is

transferred  several times over the course of a few years. If notice is not

provided in the property deed, a new owner could be unaware of its previous

use for hazardous waste management. Inadvertently, the new owner could then

initiate  construction  or  other  activities  in a manner or at a location

where  disturbance  of  the  subsurface could result in potentially harmful

exposures.  For example, by digging a foundation in a certain location, the

owner  might  unearth  an  old solid waste management unit, and in doing so

damage any engineering controls designed to prevent releases from the unit.

One  of  the  most  likely situations in which residual contamination would

remain at the property is where facilities have large areas of contaminated

soils deep in the subsurface.



    The   residual  contamination  notice  requirement  proposed  today  is

analogous  to  the  existing  requirement  contained in 40 CFR 264.119 that

facility  owner/operators  place  a notice in the deed (or other instrument

normally examined in title searches) within 60 days after the first and the

last  hazardous  waste  units  at  the  facility  are  certified  closed in

conformance  with  the  approved closure plan, in compliance with subpart G

standards.  This  notice  is required in recognition that post-closure care

may  need  to  be  instituted for some units (or, in the case of corrective

action,  areas  of  contamination)  where hazardous wastes remain in place.

Until  the  term  of  the final facility permit expires (i.e., all closure,

post-closure,  and  corrective action responsibilities at the facility have

been  fulfilled),  the  permit  responsibilities  shift to any new owner or

operator  who  assumes  control of the property. After the final permit has

expired,  the  Agency  believes that prospective purchasers of the property

should  be  made  aware of the past use of the property, legal restrictions

imposed  on  its  future  use, and the location and details of any residual

contamination  on  the  property which could influence decisions of the new

owner concerning allowable future uses.



    In  some  cases  it may be appropriate to require the owner/operator to

place  the deed notice well before expiration of the permit. For example, a

selected  remedy  may  involve  capping  (thus,  leaving in place) units or

contaminated  soils  in  an  area  of the facility. This part of the remedy

could  be  implemented well before all other corrective action requirements

at  the facility are completed. In this situation, it may be appropriate to

require   the   deed   notice  as  part  of  the  remedy  selection  permit

modification,  thus providing notice to prospective purchasers if ownership

of that portion of the facility were to be transferred at some point before

the permit is terminated.



L. Permit Requirements (Sections 270.1(c)-270.60(c)(3))



    1.  Requirement  to Maintain a Permit (Sec. 270.1(c)). Today's proposal

would  require  an  owner/operator to operate under a valid RCRA permit for

the entire length of time required to comply with requirements of part 264,

subpart  S or F corrective action. This requirement would be established by

adding  to  the  existing  language  of  40 CFR 270.1(c), which defines the

period during which owner/operators of RCRA treatment, storage, or disposal

facilities  must  maintain  a  permit.  Where corrective action is required

under  a  permit,  a  permit  will  be  necessary  for  the duration of the

activities  regardless  of  whether  other  waste management activities are

continued  at the facility. For example, at a storage or treatment facility

not  required  to  have  a post-closure permit, the permittee may decide to

cease  operation  prior  to or at the end of the term of his/her permit and

close the facility according to applicable regulations, rather than reapply

for   another  permit  term.  If  that  owner/operator  had  any  remaining

corrective  action responsibilities at the facility, today's proposal would

require  that the permit be maintained even after the hazardous waste units

are closed, until all subpart S or F requirements have been terminated.



    This  provision  is  also  likely  to  have  important  implications in

situations  involving  transfer  of  property  for  which corrective action

obligations  under  subpart  S  have  not been fully discharged. An example

would be a facility with a solid waste management unit causing a release to

ground  water  that  had been issued a permit with a schedule of compliance

requiring  the  owner/operator  to  investigate  the release and ultimately

implement  a remedy, where the owner/operator subsequently sold the portion

of  the  facility  property  upon which the solid waste management unit was

located.  In  this  and  other  situations,  EPA  believes that transfer of

corrective  action  responsibilities  to new property owners is critical to

ensuring  that  RCRA facility owner/operators are not able to evade cleanup

requirements   by   simply  selling  the  contaminated  portions  of  their

facilities. If such a transfer of ownership did not also involve a transfer

of  legal  responsibility  for  complying  with  corrective  action  permit

conditions, the effect could be a substantial number of new Superfund sites

that  could  no  longer  be addressed under RCRA. EPA does not believe that

Congress  intended, in enacting section 3004(u), to create or to allow such

an  evasion  of cleanup responsibilities. The Agency, therefore, intends to

require  new owners of property at which corrective action responsibilities

have  been identified in the permit, to obtain a permit and comply with the

corrective  action  requirements  specified in the permit. Those corrective

action requirements could, alternatively, be specified and enforced through

an administrative order (e.g., under section 7003).



    EPA specifically solicits comment on cleanup responsibilities following

transfer  of  property.  As  an  alternative to the approach outlined above

(under  which  the  new owner/operator becomes responsible for cleanup) EPA

considered  a  provision  that  would  require the former owner/operator to

maintain  corrective  action  responsibility. Under such an approach, it is

likely  that  the former owner/operator's responsibilities would be limited

to those off-site activities (i.e., activities on the transferred property)

that  the  new  owner/operator  allowed him to undertake. The former or new

owner/operator's   responsibility   to   undertake   corrective  action  on

transferred  property  may  also be dependent upon the status of corrective

action  activities  at  the  time  of  transfer. For example, a transfer of

property  before  permit  issuance  would  probably  not  implicate section

3004(u)  responsibilities.  Transfers  occurring after the permit is issued

but before remedy implementation or interim measures have begun (e.g., some

transfers  during  the  RFI  and  CMS  stages) should perhaps be subject to

different  rules  than  transfers  occurring after remedial activities have

begun.



    After  consideration  of  public comment on these questions, the Agency

intends  to  develop  a  provision  governing  {pg 30847} corrective action

responsibilities upon property transfer for the final rule.



    2. Schedules of Compliance for Corrective Action (Sec. 270.34). Section

3004(u)  of  RCRA  specifies that ''Permits issued under section 3005 shall

contain  schedules  of  compliance  (where such corrective action cannot be

completed  prior  to  issuance of the permit) .'' Section 270.34 of today's

proposal  would codify this requirement and provides a regulatory framework

for its implementation.



    Schedules  of  compliance  will be a major tool for imposing corrective

action  requirements  because,  in  most  cases, the complex and sequential

nature of the corrective action process will not allow its completion prior

to   permit  issuance.  The  provisions  of  today's  proposed  regulation,

including  plans  and  reports  for  remedial investigations and Corrective

Measure Study and remedies, will, for the most part, be implemented through

a  schedule. Consequently, the quality and detail of the permit schedule of

compliance  are  extremely  important  if  the objectives of the corrective

action program are to be achieved.



    In  addition  to  codifying  a  statutory  requirement,  proposed  Sec.

270.34(a)  states  that a corrective action schedule of compliance shall ''

contain  terms  and  conditions  deemed  by the Director to be necessary to

protect  human health and the environment.'' This provision is derived from

the  basic  statutory objective of RCRA (protection of human health and the

environment;  see  section  1003  of  RCRA),  and is a logical extension of

statutory  language  found  in  section  3004(u) which allows cleanup to be

implemented  through a schedule of compliance specified in the permit where

corrective  action cannot be completed prior to permit issuance. The Agency

believes  that  inclusion  of  this  language  in  proposed  Sec. 270.34 is

desirable to clearly assert the authority of the Region or State to include

requirements  in  the  corrective  action schedule of compliance to address

contingencies  that arise during the corrective action process and that are

not specifically contemplated by today's proposed regulation, but that must

be dealt with in order to protect human health and the environment.



    Proposed  Sec. 270.34(b) would require the permittee to comply with the

schedule imposed in the permit, and provides a time frame for notifying the

Agency  when s/he finds that such compliance will not be possible. When the

permittee  will  not  be  able  to  meet the schedule, s/he must initiate a

permit   modification  under  provisions  of  the  recently  issued  permit

modification  rule  (September  28,  1988,  53  FR 37912, discussed below).

Section  270.42(f)  of this rule establishes procedures for owner/operators

who  wish  to  initiate permit modifications where the desired modification

has  not  been  specifically  listed  as  either  a  Class  I,  II,  or III

modification.  These  procedures  are  discussed  in  detail  in the permit

modification rule and its preamble. In addition, a brief explanation of the

provisions of the proposed rule is included later in this discussion.



    In  Sec.  270.34(c)  the  Agency  proposes  a  specific  procedure  for

modifying  corrective  action  schedules  of  compliance for the purpose of

implementing  subpart S requirements. The proposed Sec. 270.34(c) mechanism

is  important  for  two reasons. First, since permits containing corrective

action  schedules  of  compliance  will  often  be  issued  before complete

information  has  been gathered as to the extent and nature of any releases

at the facility, and, therefore, the corrective action necessary to address

such releases, it will generally not be possible to adequately predict (and

thus  specifically  provide  for  in  the  schedule)  all  requirements and

contingencies  necessary to develop and implement such corrective action at

the facility. Therefore, it may often be necessary for the Agency to modify

the  schedule  of  compliance  to  provide  for new actions or to make mid-

course  changes to provisions specified in the original schedule. Secondly,

this  modification provides a mechanism to resolve disputes which may arise

between  the  permittee  and  the Agency concerning the scope or meaning of

conditions in the schedule of compliance when those disagreements cannot be

resolved through less formal means. (The potential use of this modification

procedure  for dispute resolution is discussed in more detail later in this

section of the preamble.)



    It  should  be  understood  that  the  Sec. 270.34(c) procedure will be

applied  only  in  modifying  corrective action schedules of compliance; it

will  not  be  used  to  modify  terms or conditions of the permit that are

outside  the  scope  of  the  schedule.  Given this narrower application, a

modification   made  according  to  Sec.  270.34(c)  would  not  constitute

reissuance of the permit.



    It  is the Agency's objective in creating this modification process for

corrective  action  schedules of compliance to ensure that such actions are

implemented  expeditiously,  while  preserving  the permittee's due process

rights, and ensuring adequate public participation.



    The  procedures  proposed  for  modifying schedules of compliance using

this  proposed  authority  are  found  in Sec. 270.34(c) (1)-(5); there are

fewer  procedural  requirements  for  this  modification  than  for a major

modification  initiated under the current authority of 40 CFR 270.41. Under

proposed  Sec.  270.34(c)(1),  the  Director  would notify the permittee in

writing  of  the  proposed  permit  modification.  This  notification would

include  a  description of the exact change(s) to be made to the permit and

an explanation of why the change is needed; it would also indicate the date

by  which  the  Director would have to receive any comments on the proposed

modification.  In  addition,  the  notification  would indicate whether any

supporting documentation is available for review. Further, the notification

would  include  the  name  of  the  Agency  contact  designated  to receive

comments.  At  the  same  time,  the Director would publish a notice of the

proposed   modification   in   a   locally   distributed   newspaper  (Sec.

270.34(c)(2)),  provide notification to individuals on the facility mailing

list, and place a notice in the information repository being maintained for

the facility, if the permit required that a repository be established. Each

of these notifications would contain all of the information included in the

notice  to  the  permittee. The comment period provided would extend for no

fewer  than  twenty days after publication of the newspaper notice (or, for

the  permittee, twenty days after receiving the written notification if the

notice   were  received  later  than  the  date  of  the  newspaper  notice

publication).



    If  the  Director  does  not  receive  written comments on the proposed

modification,  the  modification  will become effective five days after the

close  of  the  comment  period.  S/he  will  then notify the permittee and

individuals  on  the  facility  mailing list that the modified permit is in

effect,  and  will  place  a  copy of the modified permit in the facility's

information repository where such a repository is maintained.



    If  written  comments  on  the  proposed  modification are received, as

provided in Sec. 270.34(c)(4), the Director will make a final determination

as  to  what,  if  any,  changes  should  be made to the modification. This

determination  should generally be made within 30 days after the end of the

comment  period.  In some cases, however, it may not be practicable for the

Director  to  make the determination within that time frame; this would not

affect  the  legal validity of the modification. When the determination has

been made, the Director will provide notice to the permittee in writing and

to  the  public  through  a  notice in a local newspaper, of {pg 30848} the

final  decision on the modification. The notice will include an explanation

of  how  comments  received  were  considered  in  the  final  decision, an

indication of the effective date of the modification (no later than fifteen

days following the notification), and a copy of the final modification. EPA

believes  that  the abbreviated Sec. 270.34(c) modification procedures will

strike  an  appropriate  balance  in  most  cases  between  the  public and

government's  interest  in  ensuring  expeditious  remediation  of  harmful

situations, and the permittee's due process rights.



    It  should be understood that the procedure outlined above is a minimum

process,  and does not preclude providing additional steps or opportunities

for  review  and  comment. For example, the Director could conduct a public

meeting  during  the comment period, if it was determined to be appropriate

in  addressing  concerns  of the permittee or the public, or both. In other

cases,  the  comment  period might be extended for some period to allow for

more  thorough  review  or  comment.  Moreover,  as noted later, the burden

imposed by some changes may warrant the more extensive process provided for

in Sec. 270.41.



    Section  270.34(c)(5), as proposed, does not provide for administrative

appeals  of modifications to corrective action schedules of compliance that

are  made  under  the  procedures of Sec. 270.34. The administrative appeal

process  can be quite lengthy; experience with RCRA permit appeals has been

that   appeal   decisions   may   often  take  one  year  or  more.  If  an

owner/operator's  appeal  is  denied,  s/he  then has some recourse through

judicial appeal proceedings. Thus, the proposed Sec. 270.34(c) modification

process may be advantageous in situations where disputes between the Agency

and  the  owner/operator  will  be  most effectively resolved by reaching a

final   Agency  action  expeditiously  (see  discussion  below  on  dispute

resolution).  The  absence  of  an administrative appeal procedure will not

affect  the  owner/operator's  right  to  judicial  appeal  of modification

decisions.



    When   initiating  modifications  to  corrective  action  schedules  of

compliance,  the  Director  will  decide  on  a  case-by-case  basis  which

modification  procedure-Sec.  270.34(c), or a major modification under Sec.

270.41-is  appropriate.  A  number  of factors may influence this decision.

Since  the  Sec.  270.34(c)  procedure is less complex administratively and

should  take substantially less time to make modifications effective, it is

anticipated  that  the  process  will  be  used  for modifications that are

relatively  routine  and  do not include very large additions or changes to

the  requirements  already specified in the schedule. An example might be a

requirement  to  increase  the  frequency or methods used for ground- water

sampling. On the other hand, some Director-initiated modifications, because

of  the nature, scope, or anticipated resource burden of complying with the

new  requirement, may be more appropriately handled as a major modification

under  Sec.  270.41.  One  example  of  such  a  situation  is  the  permit

modification  for  specifying  the  remedy (see proposed Sec. 264.526); the

rule  explicitly requires the major modification under Sec. 270.41 in these

situations.



    In  addition  to  the  relative  magnitude  of the requirement(s) being

imposed  through  a  modification,  other factors such as timing and public

participation  considerations  may  affect  decisions  as  to which type of

permit  modification  should  be  used.  For time-critical actions, such as

might  be  the  case for one of several types of interim measures, the Sec.

270.34(c)  modification  would  likely  be most appropriate, since the Sec.

270.41  process  can  take  a  number  of  months  before  the modification

requirements  are  effective.  Likewise, for imposing requirements that are

especially  sensitive  or  controversial  from the community's perspective,

major  modification  procedures,  which allow maximum public input into the

substance of the permit modification, could be most fitting.



    The  two  types  of  modifications  discussed above also have different

legal  conclusions, which will also be a factor in the decision as to which

one  may be more appropriate The proposed modification under Sec. 270.41 is

subject  to  administrative  appeal.  It is subject to judicial review only

after  the appeal process has been completed. (Permit appeal procedures are

described  in  40  CFR  part 124.) As discussed earlier, the Sec. 270.34(c)

modification  would  not  be  subject  to administrative appeal. When it is

apparent  that  a  disagreement  between  the permittee and the Agency over

corrective  action  requirements  cannot  be  resolved outside the judicial

process  (such  as  might  be  the  case  in  dealing  with  a recalcitrant

owner/operator),  this type of modification would likely be the most direct

and timely means of reaching such resolution.



    The  need  for flexibility in procedural requirements for initiation of

modifications  to corrective action schedules of compliance is supported by

an  analysis  completed  for owner/operator initiated permit modifications.

EPA    issued    a    rule    on    September    28,    1988,    concerning

owner/operator-initiated  permit  modifications,  which was the result of a

regulatory  negotiation  effort involving EPA, industry, States, and public

interest  groups  (see  Sec.  270.34 schedules of compliance for corrective

action).  In  this  rule,  the  Agency  recognized that situations in which

permittees  request permit modifications represent a continuum of potential

impacts  on the permittee, the public, and the environment, which, in turn,

warrant  a  continuum  of  procedural requirements. The rule does not alter

major    permit    modifications    under   Sec.   270.41.   However,   for

permittee-requested  permit  modifications  (under  a new Sec. 270.42), the

rule  establishes  a  permit  modification classification system, with each

modification  defined  as  either  Class  I, II, or III. Proposed Class III

permit  modification  procedures  are  similar  to  the existing procedural

requirements  for a major modification initiated by the Director under Sec.

270.41   (additional   public  meetings  are  required  in  the  Class  III

procedures).  Class  II procedures are somewhat less extensive; and Class I

modifications,  which  are  of  a  limited nature, generally do not require

formal Agency approval.



    Today's  proposal  in  Sec.  270.34(c)  for modifying corrective action

schedules  of  compliance  reflects  a  balance  between  reasonable public

participation   and   the  Agency's  need  for  flexibility  in  procedural

requirements   for   permit   modifications   similar   to   that  afforded

owner/operators  in  the  recent  permit  modification rule. The relatively

streamlined  process  associated with proposed Sec. 270.34(c) will not only

reduce the administrative requirements imposed on the Agency, but will also

minimize   delays   in   implementation   of  necessary  corrective  action

requirements in appropriate circumstances.



    It  is  important  to  note that for the purposes of this provision (as

well  as  all  other provisions of the regulation proposed today), any plan

submitted  by  the  permittee  pursuant  to  a  schedule  of compliance and

approved  by  the  Director  becomes  an  enforceable part of the schedule.

Accordingly,  modifications  to  such  plans will be required to follow the

appropriate  procedures  of Sec. 270.41, 270.42, or 270.34(c). In addition,

such plans are subject to enforcement under RCRA section 3008(a).



    As  indicated  earlier in this discussion, the Agency believes that the

proposed  Sec.  270.34(c) modification procedure will {pg 30849} be used in

the  case of disputes which may arise between the permittee and the Agency.

In  practice,  the Agency presumes that the permittee and the Director will

be  able  to resolve most issues that arise during the course of corrective

action  without resorting to the procedures of Sec. 270.34(c). For example,

disputes  may arise over the scope of a remedial investigation and how many

monitoring wells may need to be installed, or the appropriate soil sampling

procedure. The permit modification proposed in Sec. 270.34(c) might be used

in  this case, although generally such issues can be resolved informally by

technical staff from both sides, or through the use of an alternate dispute

resolution  process  (described in section VI.L of this preamble). However,

in  recognition that cases may arise in which no agreement is possible, the

Agency  is  persuaded  that it needs the regulatory authority to modify the

permit,  as  necessary, to specify requirements the permittee must fulfill,

and  to  offer  both the public and the permittee an opportunity for formal

comment on the proposed changes.



    Where  situations  identified by the Director are determined by him/her

to  require  immediate  action to protect human health and the environment,

there  may  be  insufficient  time  to undertake a permit modification even

under  the relatively streamlined procedures proposed in Sec. 270.34(c). In

such  cases,  the  Director  may  take  action  under the removal authority

provided  in  CERCLA section 104 or require action under CERCLA section 106

or RCRA section 7003.



    3.  Conditions  Applicable  to  All Permits (Sec. 270.30(l)(12)). Under

Secs.  270.30(l)  (1)-(11)  of  40  CFR part 270, subpart C, the Agency has

promulgated  regulations  that specify reporting requirements applicable to

all   RCRA   permittees.  These  permit  conditions  fall  into  two  broad

categories. The first category covers those situations in which a permittee

must give notice to the Director of changes affecting the permit conditions

(e.g.,  planned physical alterations or additions to a permitted facility).

The  second  includes  those  reports  typically required of all permittees

(e.g.,  manifest  discrepancy  reports,  biennial reports, etc.). Reporting

requirements  contained  in Sec. 270.30 may be incorporated into the permit

either expressly or by reference.

    Today,  EPA  is proposing to add a new reporting requirement under Sec.

270.30(l)  relevant  to the submittal of information pertinent to subpart S

corrective     action    requirements.    Specifically,    proposed    Sec.

270.30(l)(12)(i)  would  require the permittee to submit information on any

additional  solid  waste  management  unit(s) (SWMU) discovered at any time

during the term of the permit within 30 days of the discovery of this unit.

Further,  it  would  require  the  permittee to submit information on newly

discovered  releases  of  hazardous  wastes  or hazardous constituents from

previously  identified  or newly discovered SWMUs at the facility within 20

days of discovery of the release(s).



    Currently,  EPA  or  an  authorized  State identifies all SWMUs at RCRA

facilities  during  the  RCRA  Facility  Assessment  (RFA)  prior to permit

issuance.  In  addition,  Sec.  270.14(d)  requires  the  owner/operator to

identify  SWMUs  as  part  of the facility's part B application. The Agency

realizes,  however, that additional SWMUs and releases may be discovered at

any  time  following  permit issuance. Therefore, today's proposal requires

the  facility  owner/operator  to  provide  new  data relating to SWMUs and

releases from SWMUs during the life of the permit.



    Under  Sec.  270.30(l)(12)(i)(A),  the  permittee  would be required to

submit  the  following  information on each newly identified SWMU within 30

days  of  identifying  the  SWMU:  (1)  Location; (2) type (e.g., landfill,

storage   tank);   (3)  general  dimensions;  (4)  operating  history;  (5)

specification  of  all hazardous and/or solid wastes that have been managed

in  the  unit  (if available); and (6) all available data pertaining to any

release  of hazardous waste (including hazardous constituents) to any media

from the unit. The location of the unit may be indicated on the topographic

map  submitted  by  the  facility  on  its  part  B  permit  application in

accordance  with  Sec.  270.14(b)(19)  of  40 CFR, or may be submitted on a

topographic  map of comparable scale that clearly indicates the location of

the  unit  in  relation  to other SWMUs at the facility. These data are the

same  as  those  now  required  in  the  part  B  application  under 40 CFR

270.14(d). (See Second Codification Rule of December 1, 1987, 52 FR 45788.)



    Based   on  the  information  supplied  by  the  permittee  under  Sec.

270.30(l)(12)(i)(A),  EPA  would require, as necessary (under proposed Sec.

270.30(l)(12)(i)(B))   sampling  and  analysis  data  for  the  purpose  of

determining   whether   releases  warranting  further  investigations  have

occurred.  Further investigations or corrective measures as necessary would

be imposed by amending the existing schedule of compliance or by initiating

a permit modification as provided in Sec. 270.34, depending upon the extent

of the change needed to cover necessary corrective action.

    Proposed  Sec.  270.30(l)(12)(i)(C)  would  require  the  permittee  to

identify  newly  discovered  releases  from  newly discovered SWMUs or from

SWMUs  where  no  release  had  occurred  at  the  time of permit issuance.

Information submitted would include the following: (1) The type of unit and

its  location, clearly identified on a facility map; and (2) available data

pertaining  to the release, including potential exposure pathways, controls

already  imposed  to  address  the  release, and action planned for further

cleanup.  The permittee would be required to submit this information within

20 days of discovery.



    EPA  is  persuaded that these requirements are necessary to ensure that

both the statutory requirements of section 3004(u) and Congressional intent

are  satisfied.  (See  e.g.,  S.  Rep. No. 98-284, 98th Cong. 1st Sess., 32

(1983).)  The  requirement  for  corrective  action  is  a  continuing one,

applying  not just to releases that have occurred prior to permit issuance,

but  also  to  any  releases that occur after permit issuance. Without such

requirements, the Agency might have to wait until the time of permit review

or  reissuance (in some cases as long as ten years) before newly discovered

units  or  releases  could  be  addressed  in  the  permit. Including these

requirements  in  today's  proposal  will  allow the Director to learn of a

release requiring remediation in a timely manner.

    4.  Information  Repository  (Sec.  270.36). Proposed Sec. 270.36 would

provide  the Director authority to require in the permit that the permittee

establish  an information repository. The repository would allow interested

parties access to reports, findings and other informative material relevant

to ongoing corrective action activities at the facility. A repository would

generally be required where the RCRA site is similar to sites listed on the

NPL  under  CERCLA in terms of the magnitude of contamination and potential

for exposure to hazardous wastes.



    As provided by Sec. 270.36(b), the information repository would contain

all  public  information  that  the  Director  determines to be relevant to

public understanding of corrective action activities at the facility (i.e.,

material  determined  to  be confidential business information would not be

included).  For  example, copies of RFI plans and reports and CMS plans and

reports  would generally be included in the repository. Background material

that  would  also  typically  be maintained in the repository would include

copies of relevant RCRA regulations and press releases. {pg 30850}



    The  repository  would be located at a local public library, town hall,

public  health  office,  EPA  Regional  or  State office, or another public

location  within  reasonable  distance  of the facility. In instances where

this  is  not  feasible  due  to  the  remote location of the facility, for

example,  the Director would require that the repository be established and

maintained at the facility. Regardless of the location, however, interested

persons  must  be allowed reasonable access to the repository. For example,

it  may be appropriate to require a facility to provide additional hours of

access (e.g., beyond normal business hours), depending, among other things,

on  the  degree  of  public interest in corrective action activities at the

facility and the timing of public meetings or hearings. The Agency solicits

comment on where and when the information repository should be required.



    The Director would specify requirements that the permittee must satisfy

in  informing  the public of the existence of the information repository in

the   permit   {pg  30851}  schedule  of  compliance.  (See  proposed  Sec.

270.36(d).)   At  a  minimum,  the  Director  would  require  the  facility

owner/operator   to   notify   individuals  on  the  mailing  list  of  the

repository's  establishment.  S/he might also be required to provide public

notice  in a local newspaper. An EPA contact person to whom comments can be

submitted will be identified.



    The  information repository proposed today is similar to the repository

established  at  CERCLA  sites.  Experience under CERCLA has shown that the

public  is  frequently  concerned about nearby remedial activities and that

this  interest  is  effectively  served  by  a  repository.  Without such a

repository,  the  burden  would  be  on  citizens to locate and contact the

appropriate officials knowledgeable about the site in Regional EPA or State

offices.



    There are two major differences between the information repositories in

today's  proposal  and  the  repositories  included  in the CERCLA program.

First,  information  repositories are required for all CERCLA sites whereas

they  will  be required for RCRA sites only as determined to be appropriate

by  the  Director.  In  making  such  a  determination,  the Director would

consider  the  extent  of  contamination,  the  scope and complexity of the

remedial  action,  and  the  degree  of public interest. Second, designated

information  repositories  under  CERCLA generally house the administrative

record   for   CERCLA   actions.   Under   the   RCRA  permitting  program,

administrative  records, which provide documentation for the basis of EPA's

decisions  and  other  parts  of the record, are maintained by EPA Regional

offices  (or  authorized  States)  at  the location of the Regional office.

Because the RCRA record is kept elsewhere, where it is available for public

inspection,  the  Agency  does not believe it is necessary to duplicate the

entire administrative record for RCRA sites at information repositories.



    5.   Major   Permit   Modifications   (Sec.  270.41(a)(5)(ix).  Section

270.41(a)(5)(ix) of today's proposal would add a new provision to the major

permit modification requirements allowing the Agency to reopen a permit for

good  cause  to  modify a permit for reasons arising from corrective action

requirements  under subpart S of 40 CFR part 264. The Agency would use this

authority to modify permits after a remedy has been selected under proposed

Sec. 264.525, or to recommence corrective action after a no-action decision

had  been  made  under Sec. 264.514. In addition, the Agency might use this

authority  to begin corrective action after notification of a new SWMU or a

new  release  under Sec. 270.30(1)(12). The Agency believes that it already

has   the  authority  to  modify  permits  in  this  situation  under  Sec.

270.41(a)(2),  which  allows  it  to  modify  permits  when new information

justifies  the  application  of  different  permit conditions. However, the

Agency is proposing to amend these regulations to clarify its authority.



    Modifications  under  proposed  Sec. 270.41(a)(5)(ix) would undergo the

full  permit  modification  procedures  of  40 CFR part 124- that is, there

would  be  public notice, a 45-day comment period, and a public hearing, if

requested.  In  addition,  the modification could be appealed through EPA's

administrative appeal procedures.



    The introductory paragraph of Sec. 270.41 has also been amended to make

it  clear  that  EPA-initiated  modifications  may be made pursuant to Sec.

270.34(c),  as  well  as  Sec. 270.41. This paragraph has been reprinted in

full  for  purposes  of  clarity.  EPA is seeking to change, and is seeking

comments only, on those references to new Sec. 270.34(c) and the balance of

the paragraph.



    6.   Conforming  Changes  to  Requirements  for  Permits-by-Rule  (Sec.

270.60(b)(3);  Sec.  270.60(c)(3)(viii)).  The  subpart  S regulations also

apply  to  RCRA  ''permits-by-rule''  for Class I hazardous waste injection

wells,  and  publicly  owned treatment works (POTWs) that receive hazardous

waste  by  truck,  rail  or  dedicated  pipeline  (see  40  CFR  270.60 and

conforming   changes   in  today's  proposal).  Today's  proposal  provides

conforming  changes  to Sec. 270.60 to reflect the deletion of Sec. 264.101

from  the  current  subpart  F requirements. The current ''permit-by-rule''

requirements   for   Class   I   hazardous   waste  injection  wells  (Sec.

270.60(b)(3))   and   POTWs   that  have  a  National  Pollutant  Discharge

Elimination  System  (NPDES)  permit  and  that  receive hazardous waste by

truck,  rail  or dedicated pipeline (Sec. 270.60(c)(3)(vii)) stipulate that

owners  and operators of these facilities must comply with the Sec. 264.101

requirements  in  order to obtain a RCRA ''permit-by-rule''. The references

to Sec. 264.101 in these two sections have been replaced with references to

the  requirements  of  today's  proposed  subpart  S, reflecting that these

facilities will be subject to all requirements in this new subpart. Further

information  on how EPA plans to implement corrective action at these types

of  permit-by-rule  facilities can be found in the preamble to the December

1,  1987, Codification Rule (52 FR 45788) for underground injection control

(UIC)   wells  and  in  ''Guidance  for  Implementing  RCRA  Permit-by-Rule

Requirements at POTWs.'' issued on July 21, 1987 (contact Permits Division,

Office of Water Enforcement and Permits, at (202) 475-9545).



    7.  Alternative Dispute Resolution. During the process of investigating

releases  and  studying  remedies for RCRA facilities, EPA anticipates that

some  disagreements  between  the  Agency  and the owner/operator may arise

regarding  various technical or procedural issues. For example, in defining

the  technical  scope  of  a  work  plan  for  remedial investigations, the

Agency's  technical judgment as to the numbers or placement of ground-water

monitoring wells may differ from the permittee's.



    In  most  cases, the Agency anticipates that such disagreements can and

will   be   resolved   through   continuing   communications   between  the

owner/operator  and  the  Agency.  However,  EPA recognizes that there will

inevitably be some disagreements which cannot be resolved by such means. In

these cases, there are several options the Agency may employ to resolve the

dispute  and  prevent  unacceptable  delays in implementation of corrective

action  requirements. Such options include the use of a more formal type of

dispute  resolution process; enforcement action under RCRA section 3008(a);

or  a  modification of the permit. The choice of options will depend on the

specific  issues  under  dispute and the circumstances at the facility. For

situations  where  the  requirements  at  issue  are clearly defined in the

permit  schedule  of  compliance,  but  where  the  permittee  refuses,  or

otherwise  demonstrates  an  unwillingness to comply with the requirements,

EPA  would intend to utilize enforcement options (e.g., section 3008(a)) to

compel  appropriate  action by the permittee. Alternatively, a modification

to  the  permit  schedule  of  compliance  (such  as the process defined in

today's  proposed  Sec.  270.34(c))  may often be chosen as the appropriate

mechanism  for  resolving  disputes  in situations where the requirement at

issue  is  less  specifically defined and when the Agency and the permittee

are unable to negotiate an acceptable agreement.



    The  use  of  enforcement  authorities  for  corrective action, and the

permit  modification process proposed today at Sec. 270.34(c) are discussed

elsewhere  in  today's  preamble. The remainder of this discussion focuses,

therefore,   on   the  potential  use  of  alternative  dispute  resolution

techniques to resolve disagreements.



    On  August  14,  1987,  EPA's  ''Final  Guidance  on Use of Alternative

Dispute  Resolution  (ADR)  Techniques  in Enforcement Actions'' discussing

multiple  ADR  techniques was issued. In this guidance document, the Agency

articulated  its  intention  of  encouraging the use of alternative dispute

resolution  techniques where there is reason to believe that one or more of

the  techniques  discussed  in  the  guidance may lead to expeditious final

compliance  agreements.  The  Agency  believes  that some of the techniques

discussed  in this guidance may be useful in resolving disputes which arise

in  the  corrective  action  process  under  RCRA  permits.  A copy of this

guidance is included in the docket established for today's rulemaking.



    In  particular,  EPA  is  examining  the  use of a neutral, third-party

mediator  in the context of a time-limited, non-binding negotiation process

to  resolve  corrective  action disputes. The Agency is not prescribing the

use  of  such  a  process  as  a  provision of today's proposed regulation,

however,  or  any other process. Given the Agency's limited experience with

ADR  to date it is premature to include any specific ADR technique within a

RCRA  regulatory framework. EPA intends to encourage, when appropriate, the

use  of  ADR  in  certain  situations as the RCRA corrective action program

evolves. The Agency is specifically seeking comment today on several issues

associated with alternative dispute resolution in the context of corrective

action.  These  issues  are: (1) For what types of corrective action issues

and  disputes  would  ADR  techniques  be  most useful? (2) What techniques

(e.g.,  mediation,  fact-finding,  mini-trials)  are most suitable for this

purpose?  and (3) Who should bear the cost (e.g., of third-party mediators)

of alternative dispute resolution?



M.  Conforming Changes to Closure Regulations (Section 264.113, 265.112 and

265.113)



    1. General. As discussed further in section VII.C. of today's preamble,

corrective actions undertaken at a facility may affect closure of regulated

units  under  applicable  standards of 40 CFR parts 264 and 265, subpart G.

For  example,  closure  requirements  for  regulated  units contain certain

deadlines  that  may be impractical if corrective action is required at the

facility  and  the  closing unit is being used to receive corrective action

wastes.  EPA  today  is proposing to amend the closure regulations in Secs.

264.113, 265.112, and 265.113 to simplify extension of these deadlines when

doing so would assist in implementing corrective action. The Agency is also

proposing  to  expand  part  265  closure  plan information requirements to

include information on SWMUs.



    It  is  important  to  note  that  the  part 264 and part 265 subpart G

closure regulations apply only to hazardous waste management units. Today's

proposed  changes  to closure regulations are designed to address potential

effects  of  subpart  S  or  F  corrective  action  on  the closure of such

hazardous  waste  management units. Corrective action at SWMUs that are not

used  for  the  management  of  hazardous waste is not subject to subpart G

regulations.



    In  addition,  as  discussed  earlier in this preamble, Sec. 264.551(a)

provides  the  Regional Administrator with the authority to waive subpart G

requirements (except for Sec. 264.111) for units created for the purpose of

managing corrective action waste.



    The reader should note that the proposed changes are for both permitted

hazardous  waste  units  (part  264 standards) and interim status hazardous

waste units (part 265 standards). Although today's rule primarily addresses

corrective  action at permitted facilities, interim status facilities which

close  without  an  operating  permit are potentially subject to corrective

action under orders issued pursuant to Section 3008(h) of RCRA. or they may

wish  to  conduct  corrective  action  voluntarily.  Therefore,  conforming

changes are being proposed for both permitted and interim status units.



    2.  Clarifications.  The  following discussion clarifies several points

relating to corrective action and the closure of hazardous waste management

units, and explains how existing regulations and authorities can be used to

address potential conflicting interests.

    a.  Extension  of  Closure Deadlines-(1) Notification of Closure. Under

current  regulations,  when  a  unit ceases to receive hazardous waste, the

owner/operator  is  generally  required  to  notify the Agency and initiate

closure  of  the  unit  (Sec.  264.112(d)  or Sec. 265.112(d)). In order to

perform  needed corrective action without posing unnecessary implementation

problems,  the  Regional  Administrator  may  find  it necessary to require

suspension  of  the  acceptance  of  wastes  at  the  unit temporarily. For

example, it may be necessary to drain liquids from a surface impoundment to

allow  reinforcement  or  repair of a berm to prevent migration to a nearby

surface  water  body.  However, closure of the unit may not be desirable at

that  time since available capacity in the unit, once it is repaired, could

be  beneficially used for the disposal of wastes generated in the course of

corrective  action.  The  Agency  believes that the current requirements at

Secs.   264.112(d)   and   265.112(d)  provide  sufficient  flexibility  to

accommodate temporary suspension of waste receipts to facilitate corrective

action  without  triggering the notice and closure initiation requirements.

These regulations allow the Regional Administrator to grant an extension to

the  deadline  for  beginning partial or final closure if the acceptance of

waste is suspended only temporarily and additional hazardous waste capacity

remains  in the unit. Thus, the Director may allow an extension of time for

the  initiation  of  closure  activities when capacity in the unit could be

beneficial for disposal of corrective action wastes from other SWMUs at the

facility.



    (2) Time Allowed for Closure. For hazardous waste management units that

will be required to close, but where corrective action is required prior to

or in conjunction with closure, the owner/operator may find it difficult to

comply  with the timing requirements of Sec. 264.113 or Sec. 265.113. These

provisions  currently require that within 90 days after receiving the final

volume  of  hazardous  waste  at  a unit, the owner or operator must treat,

remove,  or  dispose of the waste off-site, and that closure of the unit be

completed  within  180  days  after receiving the final volume of hazardous

waste.  However,  extensions  to  these  deadlines may be necessary because

corrective  action  may  interfere  with the owner or operator's ability to

comply  with the deadlines for completing closure. Sections 264.113 and {pg

30852} 265.113 currently contain provisions for extending closure deadlines

under  certain circumstances. EPA believes that the need to take corrective

action  at  the  unit,  or  to  receive wastes from other SWMUs, is already

included  within  the  existing  criteria  for  granting  these extensions.

However,  to  clarify  this  point,  EPA  is proposing today to amend Secs.

264.113  and  265.113  explicitly  to  include  corrective action among the

criteria  for  granting an extension to the deadline for completing closure

activities.

    b.  Modification  of  Closure Plans. Corrective actions may bring about

changes  in  unit  and  facility  design  and operation that will require a

resulting  modification to the closure plan and closure cost estimate for a

hazardous  waste  management  unit.  For example, a unit may be expanded to

accept  waste  generated during corrective action at other SWMUs as part of

the  remedy  for  a  facility.  Under  Sec. 264.112(c) and Sec. 265.112(c),

amendments to closure plans are required when changes in operating plans or

facility design affect the closure plan. When interim measures or the final

remedy  selected  affect  the closure plan for a hazardous waste management

unit,  both  the  plan  and  the  associated  cost estimate must be amended

according  to  requirements  of  subparts G and H. For permitted units, the

closure  plan  and  cost  estimate amendments may be included in the permit

modification for remedy selection or in a separate permit modification, but

both  must  be  submitted  at least 60 days prior to the proposed change in

facility  design or operation. For interim status facilities, amendments to

the  closure  plan also must be made at least 60 days prior to the proposed

change in facility design brought about by the corrective action, or within

thirty days if the change occurs during closure.



    3.  Closure Plan Information Requirements. The Agency is also proposing

to  add  Sec.  265.112(b)(8)  in  this  rulemaking  to  require  owners and

operators  to  include information about SWMUs at interim status facilities

when  they  submit  an  interim  status  closure  plan.  This  addition  is

consistent  with  the second HSWA Codification Rule. This codification rule

added  Sec. 270.14(d) to require owners and operators to submit information

about  all  SWMUs  at  a  facility as part of the Part B permit application

(December  1, 1987, 52 FR 45788). Today's proposed change would address the

need  to  coordinate  corrective  action  and closure activities at closing

interim  status  units and facilities. Since the facility owner/operator is

not  required  to  automatically  submit  a  part  B application for a unit

closing  under  interim  status,  the  Agency  will  need  a  mechanism for

obtaining  information  to  assess  the  need  for corrective action at the

facility.   Today's  proposed  addition  to  interim  status  closure  plan

information requirements is intended to provide that mechanism.



N. Conforming Change to Section 264.1(g)



    As  a conforming change, today's proposal includes an amendment to Sec.

264.1(g)  that  specifies certain explicit exemptions from the requirements

of  part  264. However, certain units that are exempted under Sec. 264.1(g)

are,  nevertheless, considered to be solid waste management units according

to  the  definition  proposed  in  Sec.  264.501.  Such units would include

on-site  accumulation  tanks  and container units, recycling units, totally

enclosed  treatment  units,  elementary  neutralization  units,  wastewater

treatment  units,  and  transfer  units.  Thus,  today's proposed amendment

clarifies  that  subpart  S  requirements  of part 264 would apply to these

units, although the exemption would continue to apply to all other part 264

requirements.



VII. Relationship to Other Programs



A. Superfund



    1.  General.  One  of the Agency's primary objectives in development of

the   RCRA   corrective   action  regulations  is  to  achieve  substantive

consistency with the policies and procedures of the remedial action program

under the Comprehensive Environmental Response, Compensation, and Liability

Act  (CERCLA),  as  amended by the Superfund Amendments and Reauthorization

Act (SARA) of 1986. The fund, which may be used for certain cleanup actions

under  CERCLA,  is  called  the  Hazardous  Substances  Trust  Fund, but is

commonly known and referred to as Superfund. Sections 104 and 106 of CERCLA

authorize  EPA  to  take  response  actions,  including removal or remedial

measures,  when  a  release or threat of a release of a hazardous substance

which may threaten human health or the environment is discovered Generally,

these  authorities  are used in situations where contamination has occurred

at sites that are not under the active control of a RCRA owner or operator.

Where  contamination is related to activities at hazardous waste management

facilities  that  are  currently  operating  or  have  conducted treatment,

storage or disposal of hazardous waste at any time since November 19, 1980,

both RCRA and CERCLA potentially apply.



    Because   the   most  comprehensive  set  of  standards  applicable  to

remediation  of  hazardous  waste sites under the control of private owners

and  operators  will,  when promulgated, be the Section 3004(u) regulation,

RCRA   corrective   action  standards  will  be  an  important  potentially

applicable  or relevant and appropriate requirement for the CERCLA program.

As  such,  a primary goal in development of the RCRA regulations will be to

establish  a  consistent  approach  between  the  RCRA and CERCLA programs.

Consistency  will  help  to  ensure that the regulated industry can gain no

advantage  by proceeding under one program rather than the other, since the

Agency anticipates that similar remedies would be selected under both.



    The  corrective  action  process  under  RCRA will parallel the process

established  for CERCLA remedial actions. This process includes preliminary

assessments and site investigations to evaluate the need for remediation at

specific  sites, selection of remedies where needed to protect human health

and the environment, remedial design and implementation of remedial action,

and  operation  and  maintenance  to  ensure continued effectiveness of the

remedy.  Procedurally,  the  activities  under  the two statutes may differ

somewhat,  since  the  permittee  implements  corrective action under RCRA,

whereas the regulatory Agency, for the most part, does so under CERCLA. (In

some  cases  CERCLA cleanups are conducted by responsible parties according

to  the  terms  of  an  order or consent decree and with Agency oversight.)

Nonetheless,  EPA  anticipates that the two programs will arrive at similar

solutions to similar environmental problems, and that actions undertaken by

one  program  will  be  adopted  by  the  other  program in cases where the

programmatic  responsibility  for  a  site  shifts  from  one to the other.

Specifically,  the  Agency  anticipates  that  there  may  be  a  number of

facilities  at  which  substantial  CERCLA  remedial  studies and/or actual

remediation  will  have been already conducted at the time a RCRA permit is

issued  (thereby  triggering the Subpart S corrective action requirements).

This  situation  is likely to be most common at Federal facilities. In such

cases, if the remedial work has been conducted according to the CERCLA NCP,

EPA  would  consider  that  work  to be consistent with the requirements of

subpart  S,  and  therefore  additional  or  different  studies  or cleanup

requirements would be unnecessary. If, however, the remedial activities {pg

30853}  conducted  pursuant  to the NCP at a RCRA facility addressed only a

portion of the units or releases at the facility requiring remediation, the

permit  would  address  any  such  remaining corrective action requirements

pursuant to subpart S.

    2.  Listing  RCRA  Sites  on the National Priorities List (NPL). EPA is

emphasizing  coordinated implementation of the RCRA and CERCLA programs. Of

particular importance is the Agency's policy for listing RCRA facilities on

the National Priorities List (NPL). Section 105(a)(8)(B) of CERCLA requires

EPA  to  establish the NPL list to set national priorities among sites with

known  or threatened releases where action under CERCLA may be warranted. A

site  must be listed on the NPL before a remedial action can be financed by

the Hazardous Substances Trust Fund established under CERCLA.



    The Agency's policy regarding the listing of RCRA facilities on the NPL

was outlined in a November 23, 1985, Federal Register notice (50 FR 47912).

The  policy  states  that  sites  that  can be addressed by RCRA subtitle C

corrective  action  authorities  generally  will be deferred from placement

unless  they fall within certain exceptions. For a more detailed discussion

of these exceptions, see 54 FR 41004-6 (October 4, 1989).



    The  proposed  RCRA  listing policy, however, does not apply to Federal

facilities.  These are listed on the NPL, as required under CERCA Sec. 120,

as amended under SARA (52 FR 17991, May 13, 1987).



    3.  Use  of CERCLA to Supplement RCRA Authorities. EPA intends to clean

up  hazardous waste sites by selecting the most appropriate response and/or

enforcement  authorities  from  among  all of those available. Accordingly,

several  CERCLA  authorities  may  be used at RCRA facilities. For example,

fund-financed removal actions under CERCLA section 104 can be taken at RCRA

sites  when  necessary  to respond promptly to a release. Although removals

may be conducted whether or not the site is listed on the NPL, such actions

must  be  undertaken  in  response  to a release or substantial threat of a

release  and  must be consistent with the criteria outlined in the National

Contingency  Plan  and CERCLA. EPA may seek reimbursement of costs of these

actions  from  generators,  transporters,  or owner/operators of treatment,

storage, or disposal facilities pursuant to CERCLA section 107.



    Where  an  ''imminent  and substantial endangerment'' may be posed by a

release  at  a RCRA facility, the Agency may employ either a CERCLA section

106 or RCRA section 7003 order. As noted earlier, these authorities will be

particularly  useful  in  addressing contamination from SWMUs that requires

prompt action.



    The  Agency  may  also  use  CERCLA  or  joint  efforts  with States in

conjunction with RCRA to address situations of ''area-wide'' contamination.

Preliminary   investigations  have  shown  that  at  some  RCRA  facilities

substantial  portions  of  on-site contamination is contributed by adjacent

facilities  not under RCRA jurisdiction. Corrective action at a single RCRA

facility alone, therefore, might do little to restore overall environmental

quality.  In  these  cases,  it  may  be appropriate to apply both RCRA and

CERCLA  authorities  or other Agency authorities in a comprehensive program

to  address  all sources of the release and provide complete remediation of

the area. This would allow a comprehensive cleanup of an area (CERCLA trust

funds  would  be  used  only where the site scored 28.5 or higher under the

HRS)  that  has  become  contaminated as a result of activities at multiple

facilities, including both operating and abandoned facilities.



    In  situations  where  CERCLA  section  104  or  section  106  remedial

activities  have been initiated, and where a RCRA permit is to be issued to

the  facility,  the  Agency  may  choose to continue these remedial actions

under  CERCLA  authority.  In  such  cases,  the  CERCLA  cleanup  would be

referenced  in  the  RCRA permit, and the Agency would take steps to ensure

that  further  cleanup  under RCRA section 3004(u) would not be required at

the affected portion of the facility. At the same time, RCRA may be used to

address  other  cleanup needs at the facility that are not addressed by the

CERCLA  action  underway. Alternatively, the cleanup may be shifted to RCRA

and  the  selected  remedy  incorporated  into  the permit through a permit

modification.



B. PCB Spill Policy Under TSCA

    EPA   regulations   under  the  Toxic  Substances  Control  Act  (TSCA)

controlling  the  disposal  of  PCBs,  published in the Federal Register of

February  17,  1978 (43 FR 7150) and May 31, 1979 (44 FR 31574), define the

term  disposal  to  encompass accidental as well as intentional releases to

the  environment. When PCBs in concentrations of 50 parts per million (ppm)

or  greater  are  improperly disposed (or when material at less than 50 ppm

got  that  way through dilution), EPA has the authority under section 17 of

TSCA  to  compel  persons  to  take  actions  to rectify damage or clean up

contamination  resulting  from the spill. Before May 4, 1987, standards for

the  cleanup  of  spilled  PCBs  were  set by EPA Regions on a case-by-case

basis.



    However,   EPA   believed   that   uniform,   predictable,   nationwide

requirements  for  the  majority  of spills would reduce risks to PCB spill

sites  by  encouraging  rapid  and effective cleanup and restoration of the

sites;  accordingly,  EPA  established  a  nationwide  policy for PCB spill

cleanup. On April 2, 1987, EPA published the TSCA policy for the cleanup of

spills   resulting  from  the  release  of  materials  containing  PCBs  at

concentrations of 50 ppm or greater. (See 52 FR 10688.)



    The  policy  requires  cleanup of PCBs to different levels depending on

spill location, the potential for exposure to residual PCBs remaining after

cleanup,  the  concentration  of the PCBs initially spilled, and the nature

and  size  of  the  population  potentially at risk of exposure. The policy

imposes  the  most  stringent  requirements  on  areas  where  there is the

greatest   potential   of   direct  human  exposures,  and  less  stringent

requirements where there is little potential for any direct human exposure.



    While  the  policy  is  expected  to  apply  to  the  majority of spill

situations,  the  policy  does  provide for exceptional situations that may

require  additional  cleanup  or  less  cleanup at the direction of the EPA

Regional offices. Further, some spills are outside the scope of the policy.

Such  spills  include:  Spills directly into surface water, drinking water,

sewers,  grazing  lands, and vegetable gardens. Final cleanup standards for

these  types  of  spills  are  established by the EPA Regional offices on a

site-specific basis.



    RCRA  corrective action authority under section 3004(u) applies to PCBs

because PCBs are listed as an Appendix VIII constituent in 40 CFR part 261.

PCB releases from solid waste management units at permitted RCRA facilities

are addressed in accordance with TSCA PCB spill cleanup policy. These solid

waste management units would often technically be considered ''old spills''

under  the  spill policy. It is the Agency's belief that the cleanup levels

and  practices  discussed  in  the  policy  will  be  appropriate  in  many

situations, and that when necessary, site-by- site evaluations should still

be required.



C. Other Elements of RCRA Subtitle C Program



    1.  Relationship  to Subpart F Ground-Water Corrective Action. Existing

RCRA  regulations  for  ground-water  corrective  action  (40 CFR Part 264,

subpart  F)  prescribe  a  specific  approach  {pg  30854}  for  detection,

characterization,  and  cleanup of contaminated ground water from regulated

land  disposal units which received waste after July 26, 1982. Subpart F is

a  ''prospective''  program  requiring  that  monitoring  be established to

detect  contamination,  and  that if detected, contaminated ground water be

removed  or  treated in place if or when a ground-water protection standard

has  been  exceeded.  There  is  additional discussion of current Subpart F

corrective action in section IV of today's preamble.



    Achieving  a coordinated, facility-wide approach to cleanup of releases

from both regulated units and other solid waste management units is a basic

objective  of  the Agency. However, the universe of units and contamination

being  addressed  by  subpart  S  corrective  action regulation is somewhat

broader in scope.

    To  ensure  consistency  in  implementing  corrective  action  at  both

regulated units (a subset of SWMUs) and other solid waste management units,

and  to  achieve  environmental  results  as  rapidly  and  effectively  as

possible,  the  Agency  is developing a proposal that would restructure the

current subpart F regulations to make them consistent with the key features

of  subpart  S.  These  proposed  revisions to subpart F are expected to be

issued  relatively soon. It is expected that these revisions will reference

a  number  of  specific sections of today's subpart S proposed regulations;

likewise, for the sake of clarity and consistency, the final subpart S rule

may  also contain cross-references (that do not appear in today's proposal)

to certain subpart F provisions.



    2.  Land Disposal Restrictions Program. As enacted on November 8, 1984,

the   Hazardous   and   Solid  Waste  Amendments  (HSWA)  to  the  Resource

Conservation  and  Recovery  Act  (RCRA)  impose  restrictions  on the land

disposal  of  hazardous  wastes.  In  HSWA,  Congress  specified dates when

particular  groups  of hazardous wastes not meeting treatment standards are

prohibited  from  land  disposal  unless  it  can be demonstrated that ''no

migration  of  hazardous  constituents  from the disposal unit or injection

zone  for as long as the wastes remain hazardous'' will occur (RCRA section

3004(d)(1),  (e)(1),  and  (g)(5)).  The  dates  specified  by Congress for

triggering the land disposal restrictions are listed below:

     Solvents and dioxins by November 8, 1986;



     California list wastes by July 8, 1987; and



     Scheduled wastes by August 8, 1988 (First Third), June 8, 1989 (Second

Third), and May 8, 1990 (Third Third).



    Note: A separate schedule was established for hazardous wastes disposed

of by deep well underground injection.



    HSWA  required  the  Agency to set ''levels or methods of treatment, if

any,   which   substantially   diminish   the  toxicity  of  the  waste  or

substantially  reduce the likelihood of migration of hazardous constituents

from  the  waste  so that short-term and long- term threats to human health

and the environment are minimized'' (RCRA section 3004(m)(1)). To date, EPA

has  developed  treatment  standards  based  on  the  performance  of  best

demonstrated available technologies (BDAT) in a series of five rulemakings.

After  the appropriate effective date, wastes for which treatment standards

have  been  promulgated  must meet those standards before the wastes may be

land disposed.



    Where  adequate treatment capacity was not immediately available on the

statutory  effective date, the Agency granted a national capacity variance.

This established an alternative prohibition effective date for the waste of

up  to  two years. During a variance, wastes not treated in compliance with

applicable  treatment  standards may be disposed of in surface impoundments

or landfills only if they meet the minimum technological requirements (RCRA

section  3004(o)).  Furthermore,  wastes  granted  this variance must be in

compliance  with  the  California list prohibitions if they are applicable,

and are subject to the paperwork requirements of 40 CFR 268.7.



    The rules promulgated to date are summarized below:



     Solvents   and   Dioxins.   On  November  7,  1986,  regulations  were

promulgated  establishing  the  implementation framework of the LDR program

(51  FR 40572). In this rulemaking, EPA promulgated treatment standards and

effective  dates  for spent solvents and dioxin-containing hazardous wastes

identified  as  EPA  Hazardous  Waste  numbers  F001-F005,  F021-F023,  and

F026-F028 (40 CFR 268.30 and 268.31).



     California  List Wastes. On July 8, 1987, regulations were promulgated

restricting  land  disposal  of the California list hazardous wastes (52 FR

25760).  Treatment  standards  were  established  for  liquid and nonliquid

hazardous  waste  containing  halogenated organic compounds (HOCs), and for

liquid  hazardous  wastes  containing polychlorinated biphenyls (PCBs). The

statutory  prohibitions  on  land  disposal  of corrosive wastes and liquid

wastes  containing  certain  metals  were  codified  and  became  effective

immediately.



     The  Scheduled  Wastes.  On  August  8,  1988,  the Agency promulgated

regulations  for  certain  scheduled wastes (40 CFR 268.10), referred to as

First  Third  wastes.  Treatment standards were established for most of the

wastes  identified  by  EPA Hazardous Waste numbers ''F'' and ''K.'' Wastes

scheduled  in  the  First  Third for which treatment standards were not set

were  subject  to  the ''soft hammer'' provisions of Sec. 268.8. On June 8,

1989,  the  Agency  promulgated  regulations  for  the  Second Third of the

scheduled  wastes  (40  CFR  268.11).  In  the Second Third final rule, the

Agency also set standards for certain First Third soft hammer wastes, Third

Third  wastes,  and newly listed wastes. This rule also set effective dates

for  underground  injected  wastes.  On May 8, 1990, the Agency promulgated

treatment  standards  and  effective  dates  for  the remaining soft hammer

wastes,  wastes  listed  in the Third Third of the scheduled wastes (40 CFR

268.12),  wastes  that  were rescheduled to the Third Third, and five newly

listed wastes.



    Separate  rulemakings  for  the  underground  injection  control  (UIC)

program  established  hazardous  waste  disposal injection restrictions and

requirements  and  set  effective  dates for underground injected solvents,

dioxins,  California  list wastes, and First Third scheduled wastes (40 CFR

parts 124, 144, 146, and 148).



    Corrective  action  taken  under today's rule must comply with the land

disposal  restriction  requirements of 40 CFR part 268. The prohibitions do

not  apply  to  hazardous  wastes  placed  into  land disposal prior to the

effective  date  of an applicable land disposal restriction, if such wastes

do  not  have  to  be  removed  or  exhumed  for treatment. Furthermore, as

explained  in  the  preamble  to  the  NCP revisions (published on March 8,

1990), the Agency has determined that placement, and thus land disposal, of

hazardous  wastes  does  not  occur  when waste is moved or treated in-situ

within  a  unit.  This is particularly important for RCRA corrective action

since many remedial actions are likely to involve treatment, consolidation,

and capping of wastes within existing units. Wastes moved or treated within

such  units  would  not  be  subject  to  the  land  disposal restrictions.

Placement  does occur, and the land disposal restrictions apply, when waste

is  removed  from the unit for treatment or other purposes and the waste or

residuals are returned to the unit, or to a different unit.



    3.  Relationship  to  section  3004(n)  Standards. RCRA section 3004(n)

requires  the Agency to promulgate standards for the control and monitoring

of   air  emissions  from  hazardous  waste  management  units  subject  to

permitting  standards  other  than  subpart  S  at  treatment, storage, and

disposal  facilities  (TSDFs).  The  goal  of these standards is to protect

human health and the environment as necessary from air emissions associated

with  {pg  30855}  management of hazardous wastes. Currently, the Agency is

developing  standards  under  section  3004(n)  that  will apply to certain

hazardous  waste management units covered by today's proposal under section

3004(u).  Section  3004(n)  standards  for  air  emissions  associated with

equipment  leaks  and  certain  process  vents  at  TSDFs  were proposed in

February  5,  1987  (52  FR 3748) and are expected to be finalized in June,

1990;  standards  for  volatile  organic  emissions from certain other TSDF

emission sources will be proposed at a later date.



    The  standards  being  developed  under  section  3004(n)  will require

engineering  controls  at  units that manage hazardous waste. Air emissions

will  be controlled through, among other things, some combination of covers

and  add-on  control  technologies  which  capture  the  air  emissions for

recovery or destruction.



    Although  standards  developed  under section 3004(n) will only address

air  emissions  from hazardous waste management units at TSDFs (a subset of

all  SWMUs),  they are expected to provide valuable guidance for addressing

air  emissions  from other SWMUs used for management of non-hazardous solid

waste.  In  addition to the standards being developed under section 3004(n)

of  RCRA,  the  Agency is examining technical approaches and policy options

for  regulating, under the Clean Air Act, air emissions from SWMUs in which

non- hazardous solid wastes are managed.



    The   Agency  is  today  proposing  a  specific  approach  to  imposing

corrective  action  requirements  on  certain  air  releases  from SWMUs in

today's  proposal.  The proposed approach is designed to be flexible enough

to  be  used  in  conjunction  with  the  section  3004(n)  standards being

developed.  When the section 3004(u) standards are developed, EPA will make

any adjustments to the subpart S standards necessary to ensure a consistent

and complementary approach.



    4.  Administrative  Orders  Under  RCRA  section  3008(h).  The section

3008(h)  authority  for  interim status corrective action orders provides a

sister  authority  to  section  3004(u)  for requiring corrective action at

non-permitted RCRA facilities.



    Corrective  action  may  be  required under section 3008(h) whether the

facility  is  operating (prior to receiving a permit) under interim status,

is  closing  or is closed under interim status, has lost interim status, or

failed  to  properly  obtain interim status. Corrective action orders under

section  3008(h)  may  be  issued unilaterally by the Agency or they may be

issued as consent agreements between the owner/operator and the Agency.



    In many cases, the entire corrective action process for a facility will

be  implemented  under  a  section  3008(h) order. However, in some cases a

facility  that  has  been  issued  a section 3008(h) order will be issued a

permit  prior  to  completion  of the activities specified in the order. In

such  cases,  the  Agency may require the owner/operator to continue all or

some of the activities under the order, or may incorporate the requirements

of the order into the RCRA permit.



    In  any case, EPA intends that equivalent environmental results will be

achieved  whether  corrective  action  requirements are imposed in an order

under  section  3008(h)  or  a permit. Accordingly. EPA expects that orders

issued  under  section  3008(h)  generally  should  follow  the substantive

requirements  of  today's  proposal  (e  g., remedy selection factors to be

considered), as well as procedural elements (e.g., triggers for moving from

one  phase  of corrective action to the next). There will, however, be some

procedural   differences   between   orders  and  permits  in  implementing

corrective   action.   On   April  13,  1988,  EPA  promulgated  rules  for

administrative procedures for issuing orders under section 3008(h). (See 53

FR 12256.)



    The  section  3008(h)  enforcement  authority  will not be delegated to

States.  States  which desire enforcement authorities equivalent to section

3008(h)  and  do  not already have such authorities in existing legislation

will  need  to  enact  parallel  statutory  enforcement  authorities. While

procedural  aspects  of issuance of section 3008(h) orders do not duplicate

the procedural aspects of today's proposed rule for corrective action under

permits,  the procedures for both are designed to ensure equivalent results

and  to  provide  adequate  participation in the process for all interested

parties.



    5.  Financial  Assurance for Corrective Action. As discussed in section

IV  of  this  preamble,  EPA  proposed financial assurance requirements for

corrective  action  (FACA)  on October 24, 1986 (51 FR 37854). The fourteen

commenters  on the FACA proposal generally supported the flexibility of the

Agency's  approach. The procedures presented in FACA and today's regulatory

changes to these procedures are summarized below.



    a.  Timing.  In  today's  rule, EPA is proposing specific language that

will  clarify  when  financial  assurance  for  corrective  action  must be

demonstrated.  Section  264.526(c)  requires  that,  after selection of the

remedy,  the  Director  shall  modify  the  facility permit and schedule of

compliance  to  require  a  demonstration of financial assurance within 120

days  of  the  effective date of the permit modification. This requirement,

which  is  a  clarification  of  the  requirement proposed in the 1986 FACA

proposal,  is  discussed  further  in  sections  VI. F  and VI.G of today's

preamble.



    In  addition  to  this  approach,  EPA  requested  comment  in the FACA

proposal  on  a  second,  more complicated, approach. In this approach, the

facility   would  be  required  to  demonstrate  financial  assurance  once

corrective  action is determined to be necessary, but before the corrective

action  measures and cost estimate are specified in the permit. Adjustments

to  the amount of financial assurance would be required after specification

of the corrective measures and cost estimate in the permit.



    Most  commenters  on the FACA proposal supported the proposed approach.

However,    some    commenters   argued   that   financial   responsibility

demonstrations  should  be  made  not  at  the  time  the  cost estimate is

completed,  but  rather  prior  to  permitting. The Agency disagrees, since

unnecessarily  early  demonstration of financial assurance may increase the

number of bankruptcies, increase the amount of unfunded corrective actions,

and thus result in less environmental protection.



    b.  Cost Estimation. The 1986 FACA proposal required facility owners or

operators  to  submit  a cost estimate for corrective action, consisting of

two  parts: (1) A year-by-year current cost estimate of required corrective

action   in  undiscounted  current  dollars;  and  (2)  the  sum  of  these

year-by-year estimates of corrective action costs. The Agency proposed that

third-party  costs,  rather  than  first-party  costs,  be used to estimate

yearly  and  total corrective action costs (i.e., costs of contractor labor

rather  than  the  owner's  or operator's own labor). The corrective action

cost  estimate  must be revised if changes in corrective measures alter the

cost  or  expected  duration  of corrective action. The proposal also would

require  the  owner  or  operator  to  adjust the cost estimate annually to

account for inflation, using either recalculations in current dollars or an

inflation  factor  derived  from  the  most  recent  annual  Implicit Price

Deflator  for  the  Gross  National  Product published by the Department of

Commerce.



    In  addition to the annual inflation adjustment required under the FACA

proposal.  EPA  is today proposing in {pg 30856} Sec. 264.527(c) to require

that  cost  estimates be revised, if necessary, upon approval of the remedy

design.  The financial assurance mechanisms must be adjusted to reflect any

changes  in  the  cost  estimate.  This requirement is discussed further in

section VI.H of today's preamble.



    c.  Allowable  Mechanisms.  Under  the October 24, 1986, FACA proposal,

owners  or  operators  who are responsible for performing corrective action

would be required to demonstrate financial assurance through one or more of

the following mechanisms: trust fund, surety bond guaranteeing performance,

letter  of  credit,  financial  test,  or  corporate guarantee. A letter of

credit   and  a  trust  fund  may  be  combined  to  demonstrate  financial

responsibility  and a single mechanism may be used to demonstrate financial

responsibility  for  multiple facilities. The rationale for authorizing the

use  of  these  mechanisms  and  for the regulatory framework for financial

assurance  for  corrective  action  is  similar  to  that for the financial

assurance  requirements  for  closure and post-closure care under part 264,

subpart  H  (47  FR  15032, April 7, 1982). The key differences between the

FACA   proposal   and  Subpart  H  are  that  insurance  and  surety  bonds

guaranteeing  payment into a standby trust fund were not deemed appropriate

mechanisms   for   corrective   action  situations  and  are  not  allowed.

Additionally, the proposed fund includes a pay-in period and pay-in formula

which  accounts  for  the  costs  of  corrective action (see 51 FR 37854 et

seq.).

    Commenters  on  the  FACA  proposal  generally  supported  the range of

allowable  mechanisms,  but  offered  specific suggestions for altering the

requirements  of particular mechanisms (e.g., shorten the pay-in period for

the  trust  fund).  The Agency will address the commenters suggestions when

the final FACA requirements are promulgated. In the interim, EPA intends to

rely on the FACA proposal as a guide. The Agency expects that in most cases

financial  assurance  will  be  demonstrated by use of instruments that are

consistent  with  the  proposed regulatory language of FACA. However, other

instruments  may  be  permissible if the owner or operator demonstrates. to

the satisfaction of the Agency, that such instruments provide an acceptable

level of financial assurance.



    The  fundamental  criteria  the  Agency  will  use  in  evaluating  the

acceptability   of   other  instruments  are:  (1)  the  certainty  of  the

availability  of  funds, and (2) the amount of funds assured. The certainty

of the availability of funds from alternate mechanisms should be equivalent

to  the certainty provided by existing financial assurance mechanisms under

40  CFR part 264, subparts G and H. For example, the alternative mechanisms

should  provide  that  the Regional Administrator or State Director has the

sole  authority  to  direct the payment or use of funds or must provide for

prompt  notification  of  intent  to  cancel  the  mechanism.  To be deemed

equivalent  in  terms  of  the  amount of funds, the alternative mechanisms

should  meet  several  criteria, such as providing that the funds cannot be

used  for  other purposes, and providing that the amount of funds are equal

to the current cost estimate.



D. RCRA Subtitle D: Solid Waste Disposal



    Today's proposal is for corrective action at facilities subject to RCRA

permits  issued  under  the  authority of section 3005 of RCRA (i.e., those

which  treat,  store, or dispose of hazardous waste as defined under RCRA).

The  disposal  of  non-hazardous  solid  waste falls under the authority of

subtitle  D of RCRA. EPA has two major roles under subtitle D. The first is

to establish minimum national performance standards (under the authority of

section  4004)  for the protection of human health and the environment from

solid  waste  disposal  facilities.  The  second is to help the States make

appropriate   solid  waste  management  decisions  by  offering  up-to-date

technical assistance.



    Some of the subtitle D standards for protection of human health and the

environment from solid waste disposal facilities could apply or be relevant

to  subtitle  C  facilities. For example. Secs. 257.3-257.8 provides safety

limits  for  the  concentration  of explosive gases generated by a facility

(defined  under  Sec.  257.2 as any land and appurtenances thereto used for

the  disposal  of  solid  wastes).  It  may  be  appropriate  to apply this

requirement to subtitle C facilities with solid waste management units that

could generate methane (e.g., landfills used for disposal of municipal-type

wastes).  Thus,  the  Agency  could  require  compliance  with the part 257

requirements  for  explosive gases if such situations were encountered at a

subtitle C facility undergoing corrective action according to subpart S.



    Passage  of  HSWA  added section 4010(c) to subtitle D. Section 4010(c)

required  EPA  to  revise  criteria  promulgated  under section 4004(a) for

facilities  that  may  receive household hazardous wastes or small quantity

generator  hazardous wastes. The statute indicated that these criteria must

include,   at  a  minimum,  ground-water  monitoring  necessary  to  detect

contamination,  location  standards, and corrective action, as appropriate.

The  statute  also indicated that the criteria should take into account the

practicable capability of such facilities.



    On  August  30, 1988, EPA proposed these revised criteria for municipal

solid  waste  landfills  (see  53  FR  33313).  The criteria for subtitle D

municipal  solid  waste landfills most relevant to today's proposal are the

criteria  proposed for ground- water monitoring and corrective action under

subpart G of 40 CFR part 258.

    The  part  258 subpart G proposal would require the owner/operator of a

municipal  solid  waste  landfill  to  establish  a  two-phase ground-water

monitoring  program.  If  parameters established for Phase I monitoring are

detected  at  a  statistically  significant  level  above  background,  the

owner/operator  must  initiate a phase II monitoring program which includes

an  initial  test for all constituents listed in appendix IX of 40 CFR part

264.  If  the  concentration  of  any  appendix  IX constituent exceeds the

established trigger lever, as discussed below, then the owner/operator must

initiate an assessment of the nature and extent of the contamination.



    Like  the  subpart  F  program  under subtitle C, the corrective action

program  proposed  in 40 CFR part 258, subpart G, for municipal solid waste

landfills  would  be  limited  to  releases to ground water. The corrective

action  program,  as  described  in subpart G, would have to be designed to

delineate the areal extent of the plume of contamination and to clean up to

maximum   allowable   constituent   concentrations  throughout  the  plume.

Ground-water  protection  standards  would be set using the same health and

environmental  based  criteria  as  those  employed in today's proposal for

subtitle  C  corrective  action  for  solid  waste  management  units.  The

requirements  for  ground-water  cleanup  in  the corrective action program

described in the revised subtitle D criteria are thus very similar to those

described  in today's subtitle C corrective action proposal. The subtitle D

revised  criteria  will  not,  however,  address  procedural  requirements;

procedures for implementing the criteria will be established by the States.



E. RCRA Subtitle I: Underground Storage Tanks



    Section  9003  of  subtitle I of the Resource Conservation and Recovery

Act  (RCRA)  directs EPA to promulgate regulations applicable to owners and

operators  of  underground storage tank {pg 30857} (UST) systems to protect

human health and the environment. Section 9003(c) specifically requires EPA

to  promulgate  regulations  applicable  to  owner/operators of UST systems

which  require  corrective  action  in  response to releases from USTs and,

further, requires the owner/operator to report the actions taken.



    Section  9003(h)  was  added  to  RCRA  by section 205 of the Superfund

Amendments  and  Reauthorization  Act  (SARA)  of 1986, which established a

Leaking  Underground  Storage  Tank  trust  fund that can be used by EPA to

clean  up  releases  of  petroleum from UST systems. Alternatively, EPA can

order  UST  owners  and  operators  to  undertake  such  cleanup. Under the

corrective  action  requirements  of  section  9003(c),  all  petroleum UST

cleanups  will  have to be conducted in accordance with the requirements in

the  regulations.  The  approach  to  UST corrective action adopts the same

basic  steps as the NCP requirements for CERCLA actions and those contained

within  today's  proposed RCRA section 3004 regulation: control the release

source,  determine the extent of the contamination, determine the extent of

the  remediation required, and take the necessary cleanup actions. Specific

differences  in  the  programs  reflect  the  different scope and nature of

implementation under the different programs.



    EPA  issued  final  technical  standards governing petroleum and CERCLA

hazardous  substance  UST  systems on September 23, 1988 (---- FR -------).

Approximately  two  million USTs will be affected by the regulations, and a

wide variety of release situations and hydrogeologic settings are expected.

These  standards  would require owners and operators of leaking UST systems

to  take  certain  actions  upon  confirmation  of  a  release.  Owners and

operators  must  report  confirmed  releases  to the appropriate regulatory

authority  and  begin  immediate cleanup steps. Immediate measures required

under the proposed standards include mitigation of safety and fire hazards;

initiation  of  free  product  recovery,  if  applicable; and assembling of

information   on   the   nature  and  quantity  of  the  release  and  site

characteristics.  The  owner/operator  must  submit,  to  the  implementing

agency, reports describing these immediate steps, as well as the design and

implementation  of  free product recovery systems. A corrective action plan

would be required for longer-term cleanups addressing soil and ground-water

contamination.  Cleanup levels would be established on a site-by-site basis

as  approved  by  the  implementing agency (typically the State) that would

oversee the cleanup by the owner or operator.



    The first stage of the UST corrective action process requires immediate

steps to abate imminent safety and health hazards whenever a release from a

petroleum  UST  is  confirmed The owners and operators must investigate the

presence  of free product and, if present, begin free product recovery. The

owner/operator must also submit information characterizing the site and the

nature  of  the  release. If, after reviewing this preliminary information,

the implementing agency determines that the product may have reached ground

water  or  that  contaminated  soil  is  in  contact with ground water, the

owner/operator  must  characterize  the  extent  and  location  of soil and

ground-water   contamination.   The   implementing  agency  will  use  this

information  as  the  basis  for determining, through a site- specific risk

assessment,  whether the owners and operators will be required to undertake

a longer-term correction action.



    This  second  stage of the corrective action process addresses soil and

ground-  water  cleanup.  The  site-specific  analysis  is  the  basis  for

prescribing  the  extent  and  timing of cleanup that would be required for

longer-term corrective action. The assessment would be based on analysis of

site-specific  conditions  and problems posed by the release. Factors to be

considered  include:  the  quantity  of  material  released;  the mobility,

persistence.  and  toxicity  of  the  material;  the exposure pathways; its

relationship to present and potential ground-water well locations and uses;

and  any  relevant  standards.  Technology-based cleanup requirements would

also  be  possible under this approach if: (1) The cleanup level set during

the  UST corrective action process is found to be unattainable with current

technology;  (2) it is shown that the remaining contamination does not pose

a  substantial  present  or  potential  hazard  to  human  health  and  the

environment;  and  (3)  monitoring procedures are instituted to ensure that

the conditions remain stable or improve.



    EPA's  approach  to  corrective  action at underground storage tanks is

largely  shaped  by  the  enormous  size  of  the regulated universe. These

factors,  as  well  as  the  absence  of  permitting requirements for USTs,

explain  the  procedural differences between corrective action for USTs and

today's proposal.



    EPA  estimates  that there are approximately two million petroleum USTs

at  about  700,000 facilities as well as 50,000 hazardous substance USTs at

30,000 facilities potentially subject to subtitle I. Because of the size of

this  universe,  EPA  believes  that the program is best implemented at the

State  and  local  level,  and  that  it should be, to the extent possible,

self-implementing.  Thus, the UST rule would require that certain automatic

actions  be taken at the determination of a release: mitigation of fire and

safety hazards, recovery of free product, and repair of the leak or removal

of the tank. These are all straightforward actions particularly relevant to

the  UST  universe and are amenable to self-implementing standards. At RCRA

permitted  facilities,  contingency  plans and tank standards would require

comparable  action  for  hazardous waste units. However, the Agency did not

adopt  comparable  self-implementing provisions-beyond the regular facility

subtitle  C  standards-in today's rule because of the much wider variety of

units  that  would be subject to subtitle C corrective action and the close

Federal or State oversight afforded by the permit process.



    The   UST  rule  would  also  require  long-term  remedial  action  for

ground-water and soil contamination, based upon a site-specific assessment,

after  immediate  action  had  been taken. Because of the large size of the

regulated universe, the absence of a national permitting system under which

to  carry  out  cleanup,  and  the  necessity  of local implementation, EPA

believes  a  procedurally  less  prescriptive approach to selecting cleanup

strategies and cleanup levels is necessary for USTs.



    Some  USTs  are  potentially  subject to corrective action requirements

under  both subtitle I and today's rule. Specifically, releases from an UST

containing  solid  wastes  at  a  RCRA permitted facility may be subject to

corrective  action  requirements  under  both  programs.  In order to avoid

confusion  and  because  USTs located at RCRA facilities will be subject to

the  oversight  provided  by  a  site-specific  permitting process, today's

regulations,  when  promulgated,  will  be the applicable corrective action

requirements  for USTs subject to section 3004(u). The final UST rules also

clarify  the applicability of the subtitle I corrective action requirements

to  USTs  located  at  RCRA  permitted  facilities  by  excluding them from

coverage under subtitle I.



F. Federal Facilities



    Many  Federal agencies have facilities which require RCRA permits. Some

of  these  agencies  have  developed remedial programs which apply at their

facilities {pg 30858} in addition to EPA programs under the RCRA and CERCLA

statutes.    Regardless   of   any   self-   imposed   remedial   programs,

federally-owned or operated facilities must comply with all RCRA and CERCLA

requirements  (with  certain  limited exceptions) in the same manner and to

the  same  extent  as most non- governmental entities. The objective of the

RCRA  corrective  action  program  at  Federal  facilities,  as at all RCRA

facilities, is to ensure protection of human health and the environment.

    Section  6001  of  RCRA  requires  any agency of the Federal Government

engaged  in  the  management  or disposal of hazardous waste to comply with

both substantive and procedural requirements under RCRA as well as with any

other  applicable  requirements  for  the  management  of  hazardous waste,

including Federal, State, interstate and local requirements. CERCLA section

120(a) makes Federal facilities subject to CERCLA in the same manner and to

the  same  extent as private facilities. Section 120(i) also makes it clear

that  the  special  provisions for Federal facilities in Section 120 do not

impair  any  obligations  they  have  to  comply  with  RCRA  requirements,

including  corrective  action.  In accordance with section 120 (c) and (d),

EPA   has  established  a  comprehensive  Federal  agency  hazardous  waste

compliance  docket  and will list Federal facilities on the CERCLA National

Priorities List (NPL) if they meet the NPL listing criteria.



    Many  Federal  facilities at which hazardous wastes are managed will be

subject   to  both  CERCLA  remedial  action  and  RCRA  corrective  action

authorities  In  many such cases, EPA intends to coordinate the application

of  RCRA  and  CERCLA authorities through the use of interagency agreements

(IAGs),  as  provided  under the authority of section 120(e) of CERCLA. The

IAG  will  provide  the  vehicle for explicitly defining the procedural and

technical  requirements  for  corrective  action,  in  satisfaction  of the

statutory and regulatory authorities of both RCRA and CERCLA.

    While it is the responsibility of Federal facilities to comply with the

requirements  of  both  the  RCRA  and CERCLA programs, the Agency plans to

continue  its  efforts  to  coordinate  the  activities required under both

programs  with  those  under  already-established Federal facility remedial

programs.  For  example,  the Department of Defense (DOD) has developed the

Installation   Restoration   Program   (IRP)   to   identify   and  cleanup

contamination  resulting  from  past  waste  management  practices  at  DOD

facilities.  IRP  conducted activities will often serve to satisfy RCRA and

CERCLA requirements. Furthermore, the Agency is aware that in some cases an

Environmental  Impact  Study  (EIS) will be conducted at a Federal facility

during the same time frame as the RCRA Corrective Action investigations and

studies are undertaken. To the extent that the information generated by the

EIS  is deemed relevant by EPA to the needs of Corrective Action, EPA would

not  intend  to  require duplicative information to be generated to satisfy

corrective  action  requirements. In fact, it may be possible in some cases

to  merge  the  two  studies  into  one  integrated  document. EPA intends,

however,  to  oversee  and, if necessary, direct the scope and substance of

investigations  and cleanup activities at DOD and other Federal facilities.

In  addition,  EPA  anticipates  that  many  States will exercise oversight

authority  under  State laws to review and participate in corrective action

decisions at Federal facilities.

VIII. Public Involvement



    Effective  public  involvement  efforts  within  the  corrective action

program  will  enable  the interested public to receive accurate and timely

information  about  remedial  plans and progress and to comment on proposed

actions  at  significant  decision points. The statutory public involvement

requirements  for  permitting contained in RCRA section 7004 are elaborated

in  regulatory  requirements  at 40 CFR parts 124 and 270. Today's proposal

includes  additional  requirements intended to promote active and effective

communication   between   the  interested  public,  the  regulatory  agency

responsible  for  implementation  of the corrective action program, and the

permittee.



    The first required public involvement occurs before a draft RCRA permit

is  developed.  At  the time the permit application is submitted, a mailing

list  must  be assembled by EPA or the State for the community in which the

facility is located. (See 40 CFR 124.10(c)(1)(viii).) The list serves as an

important  communications  tool  to  allow  the  regulatory agency to reach

interested  members of the public with announcements of meetings, hearings,

events,  and  available  reports  and  documents.  Guidance on developing a

comprehensive  mailing  list  is  available in the January 1986 Guidance on

Public Involvement in the RCRA Permitting Program.

    After  developing  a draft permit, the regulatory agency is required to

provide  public  notice  that  a  draft  permit  has  been  prepared and is

available  for  public  review.  (See  40  CFR  124.6.)  The notice must be

published  in  a major newspaper and broadcast over local radio stations. A

45-day  public  comment  period  on the draft permit must follow the public

notice.  If  a written request is received, EPA or the State is required to

hold  an  informal  public  hearing. A 30-day advance notice containing the

time  and  place  of  the hearing is required. In addition, a fact sheet is

developed  to  accompany  every  draft  permit. It includes the significant

factual  and  legal  bases  used in preparing the draft permit. The comment

period  for  the  draft  permit  will  provide the public an opportunity to

comment  on  corrective  action conditions contained in the permit. In most

cases,  requirements  for the RCRA Facility Investigation (where necessary)

will be included in the schedule of compliance in the draft permit.



    When  a final decision is reached on whether to issue or deny a permit,

EPA  regulations  require  that  a  notice  of the decision be sent to each

person  who  submitted  written  comments  on  the  draft  decision  or who

requested  such  a  notice.  In  addition,  a  response  to all significant

comments  must  be  issued  by  the  Agency  or  the State. The response to

comments  must  include  a  summary of substantive comments received and an

explanation  of either how they were incorporated or addressed in the final

permit condition or why they were rejected.



    In  addition  to the established public involvement activities required

during  the  permitting process, today's regulation proposes in Sec. 270.36

to  provide the Director with the authority to require an additional effort

to  keep the interested public informed of activities at the site. Proposed

Sec.  270.36  would  allow  the Director to require the establishment of an

information   repository  that  would  house  documents  pertinent  to  the

corrective action activities near the facility. The details of the proposed

repository  are discussed in section VI.L of today's preamble. In addition,

today's proposal would require the permittee to mail a summary of the final

report  of  the  RCRA  Facility  Investigation  to  all  individuals on the

facility's  mailing list to keep interested persons informed of findings at

the site.



    Today's  proposal  would  also  require  a major permit modification to

incorporate  remedy selection. The modification would provide an additional

opportunity   for   public  involvement.  This  modification  would  follow

established  public  participation  procedures  under  part  124  for major

modifications.  In  addition,  today's  proposal  provides  that additional

permit  modifications  initiated by the Agency or the permittee will be {pg

30859}  classified on the basis of their potential effect on the permittee,

the  affected  public,  and  the  environmental impact of proposed changes.

Those  that  are classified as major modifications will follow the existing

procedures for major modifications as described above. Those that have less

significant  impacts  will  follow  the  procedures described under today's

proposed Sec. 270.34(c) or those issued on September 28, 1988 (53 FR 37912)

for  owner/operator  initiated modifications. In all cases there will be an

opportunity for public review and comment. Section VI.L of today's preamble

discusses  the classification of permit modifications for corrective action

and their related procedural requirements more fully.



    There  may be some actions taken during the course of a permit that are

not  reflected  in  the  initial permit and are not the subject of a permit

modification.  For  example,  many  of the detailed activities taken by the

permittee  in  implementing the RFI or in designing the CMS plan may not be

specified  in  the initial permit. In some cases, EPA and the permittee may

reach  a mutual agreement about the exact nature of the required activities

(within  the  general  scope  of  the  permit),  and the specifics of these

activities  may  not  be reflected in a permit modification. In such cases,

the  specific  activities agreed to will be documented on the permit record

and  the public will have an opportunity to comment on them when the permit

is modified at the time of remedy selection. This approach would be limited

to activities that would not constitute a major change that might otherwise

warrant  application  of the public participation requirements specified in

Sec. 7004 of RCRA.



    EPA  believes  that the approach outlined above provides an appropriate

balance  between the need to involve the public in the remedial process and

the  need  to  proceed expeditiously to remedy releases to the environment.

The  public  will  have  a  full  opportunity  to  comment  on all remedial

activities  undertaken  during  the  term  of the permit, and not otherwise

subject  to public scrutiny, at the time of remedy selection. To the extent

that  public  comment  takes legitimate issue with such activities, EPA may

need  to  revisit some of these activities or modify its decision regarding

the  remedy.  Accordingly,  EPA  will  be very sensitive to possible public

reaction in specifying activities to be undertaken during the course of the

permit without public involvement.



    Public  involvement  activities  required in the permitting process and

proposed  today  for  the corrective action program are similar, though not

identical,  to  those  established  under the Superfund Community Relations

Program.  Activities  proposed  today are in addition to public involvement

activities conducted at RCRA facilities targeted by the Agency for expanded

public  involvement  because  of  the  high  potential  for exposure to the

population  or because of a high level of interest in the community. Public

involvement  efforts  at  RCRA sites listed on the National Priorities List

and/or  facilities  which will accept Superfund wastes should be integrated

with  concurrent  Superfund  community  relations  efforts  to  the  extent

possible.



    EPA  and  State  offices, as a matter of policy, jointly issue permits.

Where  States  are  authorized  to  implement  only  some  portions  of the

hazardous  waste  program,  the  State  and  EPA  may  also  conduct public

involvement activities jointly.



IX. State Authorization



A. Applicability of Rules in Authorized States



    Under  section  3006  of  RCRA,  EPA  may authorize qualified States to

administer  and enforce the RCRA program within the State. (See 40 CFR part

271  for  the  standards  and  requirements  for  authorization.) Following

authorization,  EPA retains enforcement authority under sections 3008, 7003

and  3013  of  RCRA,  although  authorized  States have primary enforcement

responsibility under section 7002.



    Prior  to  the  Hazardous  and Solid Waste Amendments of 1984 (HSWA), a

State  with  final  authorization  administered its hazardous waste program

entirely  in  lieu  of EPA administering the Federal program in that State.

The Federal requirements no longer applied in the authorized State, and EPA

could not issue permits for any facilities in the State which the State was

authorized  to  permit.  When new, more stringent Federal requirements were

promulgated or enacted, the State was obliged to enact equivalent authority

within  specified time frames. New Federal requirements did not take effect

in  an  authorized  State until the State adopted the requirements as State

law.



    In  contrast,  under section 3006(g)(1) of RCRA, 42 U.S.C. 6926(g), new

requirements  and  prohibitions  imposed  by HSWA take effect in authorized

States  at the same time that they take effect in nonauthorized States. EPA

is  directed to carry out those requirements and prohibitions in authorized

States,  including  the  issuance  of  permits,  until the State is granted

authorization  to  do  so.  While  States  must  still  adopt  HSWA-related

provisions   as   State   law  to  retain  final  authorization,  the  HSWA

requirements apply in authorized States in the interim.



B. Effect on State Authorizations



    1.  Schedule  and  Requirements  for  Authorization.  Today's  rule  is

proposed   pursuant  to  section  3004(u),  section  3004(v),  and  section

3005(c)(3)  of  RCRA,  provisions  added  by HSWA. Therefore, the Agency is

proposing  to  add  the  requirements  to Table 1 in 40 CFR 271.1(j), which

identifies  the  Federal program requirements that are promulgated pursuant

to  HSWA and take effect in all States, regardless of authorization status.

States  may  apply  for  either interim or final authorization for the HSWA

provisions  identified  in  Table  1,  as  discussed in this section of the

preamble.



    EPA  will  implement  today's  rule in authorized States until (1) they

modify their programs to adopt these rules and received final authorization

for the modification or (2) they receive interim authorization as described

below. Because this rule is proposed pursuant to HSWA, a State submitting a

program   modification  may  apply  to  receive  either  interim  or  final

authorization under section 3006(g)(2) or section 3006(b), respectively, on

the  basis  of requirements that are substantially equivalent or equivalent

to  EPA's.  The procedures and schedule for State program modifications for

either  interim  or  final authorization are described in 40 CFR 271.21. It

should   be   noted  that  all  HSWA  interim  authorizations  will  expire

automatically  on  January  1,  1993  (see  40  CFR 271.24(c)); EPA invites

comment on whether this deadline should be extended for cause.

    EPA  invites  comment  on  an  expedited  process  for granting interim

authorization  for  today's  rule,  pursuant to RCRA section 3006(g)(2), to

States  already  authorized  for  HSWA  corrective  action  pursuant to the

initial  codification  of  section  3004(u) at 40 CFR 264.101 (50 FR 28747,

July  15, 1985). An expedited process is needed if such States are to avoid

losing  their  authority  to  issue  corrective  action  permits  upon  the

effective  date of today's rule. This expedited process would not involve a

detailed  review of the State regulations. Rather, when determining whether

the  State's regulations are substantially equivalent to today's rules, EPA

would   consider  the  State's  statutory  authorities  to  impose  similar

corrective  action requirements. Because today's rules clarify the scope of

and  are  consistent  {pg 30860} with, the July 15, 1985, codification rule

for  which  some  States  are  authorized,  these authorized States already

should have statutory authority to implement today's rules.



    To  ensure  that today's rules are uniformly applied by a State granted

interim  authorization  under  this  approach, a State applying for interim

authorization  would  be required to commit, in the State-EPA Memorandum of

Agreement,  to  implementing its corrective action authorities according to

the subpart S requirements. In particular, permits issued by the State must

reflect  subpart  S  requirements  even  prior  to adoption by the State of

regulations  equivalent  to  and  no  less  stringent  than  the  subpart S

requirements.  The  State  interim  authorization  application  under  this

approach, then, would consist of the revised Memorandum of Agreement (MOA),

and  a  revised Attorney General's (AG) statement certifying that the State

has  the  authority  to  enter  into  the  Memorandum of Agreement and that

permits  issued  with  the  conditions  agreed  to  in  the  MOA  would  be

enforceable  under  State  law. EPA specifically invites comment on whether

State law allows the State to make this MOA commitment.



    EPA  believes  this  expedited process will minimize disruptions to the

State  permit  process.  A  State  already authorized for corrective action

which  applies for interim authorization for today's rule shortly after its

publication as a final rule should be able to receive interim authorization

prior  to  the  effective  date  and  thus avoid the need for EPA to resume

responsibility  for issuing permits containing corrective action conditions

in that State.



    Although  requirements  imposed  pursuant to section 3006(g)(1) of HSWA

take  effect  in  authorized  States  at  the  same time as in unauthorized

States, EPA believes that this requirement applies only to the promulgation

of  the regulations identified in Sec. 271.1(j) and only to the extent that

these  requirements  put  the  HSWA  program  in  place. In passing section

3006(g)(1),  Congress  was  concerned  that  no  delay  occur  before these

requirements,  once  in  place  in the Federal program, became effective in

authorized  States.  However,  Congress  clearly  did  not  intend  for the

authorized  State program's authority to return, in part, to EPA every time

EPA  were  to  promulgate  a  subsequent,  more  stringent  modification or

addition to these requirements promulgated under HSWA. Thus, once the basic

framework  for  the HSWA provisions has been promulgated and is essentially

complete,  subsequent  regulations  promulgated  by  EPA will be adopted by

States  according  to  the  timelines  for  non-HSWA  regulations in 40 CFR

271.21(e).  In regard to today's rule, EPA is soliciting comment on whether

the  HSWA  corrective  action requirements should be considered essentially

complete with the adoption of these requirements.



    40  CFR  271.21(e)(2) requires that authorized States must modify their

programs  to  reflect Federal program changes, and must subsequently submit

the  modifications to EPA for approval. The deadlines by which a State must

modify  its program to adopt this proposed regulation will be determined by

the  date  of  promulgation  of  the  final rule, in accordance with 40 CFR

271.21(e).  These  deadlines  can  be  extended  in  certain  cases (40 CFR

271.21(e)(3)).  Once  EPA approves the modification, the State requirements

become subtitle C RCRA requirements.



    A  State  that submits its official application for final authorization

less  than  12  months  after  the effective date of these standards is not

required  to  include  standards  equivalent  to  these  standards  in  its

application.  However,  the  State must modify its program by the deadlines

set forth in 40 CFR 271.21(e). States that submit official applications for

final  authorization  12 months after the effective date of these standards

must include standards equivalent to these standards in their applications.

40  CFR 271.3 sets forth the requirements a State must meet when submitting

its final authorization application.



    In  addition  to  meeting  the requirements in 40 CFR part 271, a State

seeking  authorization  for  today's  rules must demonstrate the ability to

capably  implement  the  base  RCRA  program as well as the additional HSWA

elements.  EPA's  assessment  of  a  State's  capability  will  reflect  an

evaluation  of  the  State's entire authorized program. The assessment will

examine  not  only  whether  a  State  is effectively implementing the base

program, but also how that State may implement additional program areas.



    2.  States  with  Existing  Corrective Action Programs. States that are

authorized  for  RCRA,  but  not  for  corrective  action  may already have

requirements  under State law similar to those in today's rule. These State

regulations  have  not  been assessed against the Federal regulations being

proposed  today to determine whether they meet the tests for authorization.

Thus,  a State is not authorized to implement these requirements in lieu of

EPA  until  the  State  program modification is approved. Of course, States

with  existing  standards  may  continue  to  administer  and enforce their

standards  as  a  matter of State law. In implementing the Federal program,

EPA  will  work  with  States  under  cooperative  agreements  to  minimize

duplication  of  efforts.  In  many cases, EPA will be able to defer to the

States  in  their  efforts  to  implement  their programs, rather than take

separate actions under Federal authority.



    Additionally,   some   States  have  received  authorization  for  HSWA

corrective  action  pursuant to the initial codification of section 3004(u)

at  40  CFR  264.101  (50  FR  28747,  July  15,  1985). The July 15, 1985,

Codification  Rule  explains  at  50  FR 28730 that a State's authorization

status may change in response to further implementation of HSWA, i.e., when

EPA  publishes  regulations that further define initially codified rules. A

State  that  was  authorized for corrective action under the July 15, 1985,

Codification  Rule  will  no  longer  be  authorized when today's rules are

promulgated  unless  the  State  applies  for and receives interim or final

authorization  before  the  effective  date  of  the  final promulgation of

today's  rules.  However, if such States have not obtained interim or final

authorization  by the effective date, cooperative agreements can be used so

as to avoid interruption of ongoing State corrective action activities. See

the  above  discussion of an expedited process for interim authorization of

such States.



C. Corrective Action and Mixed Waste Authorization



    On  July  3,  1986, EPA published a notice that, to obtain and maintain

authorization  to administer and enforce a hazardous waste program pursuant

to subtitle C of RCRA, States must have authority to regulate the hazardous

component  of  radioactive  mixed  wastes  (51 FR 24504). Radioactive mixed

wastes  are  wastes  that  contain  hazardous  wastes  subject  to RCRA and

radioactive  wastes  subject  to  the  Atomic Energy Act (AEA). Radioactive

mixed wastes (except for the component subject to AEA) are considered to be

a  ''solid  waste''  for  purposes  of  corrective  action  at  solid waste

management   units.   Therefore,  in  order  to  obtain  authorization  for

corrective   action,   States   must   have  previously  obtained  or  must

simultaneously  obtain  authorization  for their definition of solid waste,

which  must not exclude the non- AEA components of radioactive mixed waste.

This  is  because  States  must  be  able  to apply their corrective action

authorities to mixed waste units. {pg 30881}



X. Regulatory Impact Analysis

    A. Executive Order No. 12291 . Regulatory Impact Analysis



    1.  Background. In conjunction with the development of today's proposed

rule,  EPA  performed  a  regulatory  impact analysis (RIA), as mandated by

Executive   Order   12291.   These  analyses  are  required  for  ''major''

regulations,  defined  as  those  likely to result in annual effects on the

economy  of  Sec.  100 million or more; a major increase in costs or prices

for  consumers  or individual industries; or significant adverse effects on

competition,   employment,   investment,   productivity.   innovation.   or

international trade. The results of the RIA prepared for today's rulemaking

demonstrate that the rule is a ''major'' regulation.



    Pursuant  to  the Regulatory Flexibility Act, 5 U.S.C. 601 et seq., the

Agency is also required to assess the impact of a proposed or final rule on

small  entities  (i.e.,  small  businesses,  small organizations, and small

governmental  jurisdictions).  The  results  of  this assessment, which was

conducted as part of the RIA, are presented below in section X.B.



    The  complete  regulatory  impact analysis document is available in the

docket  established  for  this proposed rule. The following is a summary of

the  analytical  methodology used in conducting the RIA, and the results of

the analysis.

    2.  Summary and Major Conclusions. The analysis conducted by the Agency

indicates  that  the  corrective  action rule may result in a wide range of

costs,  depending  on  the nature of the remedies selected in site-specific

decisionmaking.  Given  the  large,  national  scope  of this rule, and the

flexibility  provided  by  the  provisions outlined in this proposal, these

uncertainties are expressed in the following discussion.



    Overall,  the  analysis  found  that about 31 percent of facilities are

projected  to  require  corrective action for releases to ground water from

solid  waste  management  units  (Media  other  than  ground water were not

analyzed  due to data and modeling limitations.) The average annualized per

facility  costs  for non-Federal facilities under today's proposed rule are

estimated  to range between $1.8 million to $0.4 million. The total present

value national cost of the proposed rule, as an increment over the pre-HSWA

corrective  action  program,  is likely to range between $7 billion and $42

billion. The costs of cleaning up Federal facilities, presented separately,

are much more uncertain and could range between $3 billion to $18 billion.



    The above results reflect two of four regulatory alternatives that were

analyzed  which the Agency believes reflect the flexibility inherent in the

proposed  rule.  These alternatives provide an upper and lower bound to the

costs  of  the  proposed  rule  and  reflect the Agency's uncertainty about

several  of  the data and assumptions used in estimating costs, such as the

types  of remedial measures that will be ultimately implemented. While both

regulatory  alternatives  would require cleanup to health-based levels, the

key  distinction  between  them  is  in  the choice of allowable corrective

action  remedies. The analysis assumed that the lower bound option would be

more  flexible  than  the  upper  bound  (e.g., by allowing use of exposure

controls  in  cases  where  certain remedies were technically infeasible or

prohibitively expensive).



    3.  Scope  and  Analytical  Approach. In developing the RIA for today's

proposed  rule,  the  Agency analyzed both qualitatively and quantitatively

several basic alternatives which could have been adopted in structuring the

corrective  action  rule  The  alternatives  studied  cover a range, from a

highly  conservative  ''cleanup  to  background'' approach with very little

flexibility   in   adjusting  remedies  for  site-specific  conditions,  to

alternatives   which   trigger   cleanup   of   releases  in  only  limited

circumstances,  and  would  allow,  in  many cases, contamination to remain

within  a facility's property and beyond. The analysis indicates that these

alternatives have quite different environmental results, as well as impacts

on the regulated community.



    In  developing  the  RIA,  EPA assembled data to estimate the potential

scope  of  the  RCRA corrective action program. The data used in generating

these  estimates was primarily obtained from the Agency's existing database

on  RCRA  facilities  (the  ''Hazardous  Waste Data Management System,'' or

HWDMS),  and  an analysis conducted for the RIA which examined a sample set

of  65  RCRA Facility Assessment (RFA) reports. These reports are typically

prepared  by  EPA  or  the  States  prior  to issuance of RCRA permits, and

provide preliminary findings as to what releases have or may have occurred,

and  what  investigations should be conducted to verify and/or characterize

the  releases.  These preliminary RFA findings were extrapolated to provide

estimates  of  the  numbers  and  types  of  facilities  that  may  require

corrective  action. Certain data from the reports were also used to support

modeling  for  the  quantitative  analysis of the RIA. A summary of the RIA

estimates  as to the size and distribution of RCRA facilities that may need

corrective   action   are  presented  in  the  following  section  of  this

discussion.



    4. Potential Scope of the Corrective Action Program. EPA estimates that

there  are  approximately  5,700 facilities regulated under RCRA subtitle C

that  are  potentially  subject  to  the  corrective  action authorities of

sections  3004(u) and 3008(h). Based on preliminary survey results from RFA

reports,  it  is estimated that roughly 80,000 solid waste management units

exist  at  these  facilities;  this  number  includes some 3,000 land-based

hazardous  waste  management  units  (e.g.,  hazardous  waste landfills and

surface  impoundments)  that were subject to corrective action prior to the

1984  HSWA  amendments.  The  number  of  solid  waste  management units at

individual  facilities  varies  widely,  up  to  as  many as 1,300. Federal

facilities,  because of their large size, typically contain many more solid

waste  management units-an average of 55 per facility, according to the RFA

survey  results. The survey indicated that there are an average of 12 solid

waste  management  units  (including  hazardous  waste management units) at

non-Federal facilities.



    The  types  of  solid  waste  management  units found at facilities are

diverse.  More  than  one- third (36 percent) are tanks used for storage or

treatment   of   wastes.   Landfills   comprise  16  percent,  and  surface

impoundments  15 percent. The remainder are units such as container storage

areas,  piles,  land  treatment units, incinerators and other miscellaneous

units.  The  survey  also  found a wide diversity within unit categories in

terms  of  size, age, general condition, types of wastes managed, and other

factors.



    The survey revealed that, on average, 62 percent of all facilities have

indications  of  possible  releases,  based  on RFA findings, sufficient to

require   follow-up   remedial   investigations  (i.e.,  RFIs).  Typically,

facilities  that  have  subtitle C land disposal units and incinerators are

more  likely to require follow-up investigations than are treatment/storage

facilities  (74  percent,  70  percent  and  56 percent, respectively). The

Agency's  experience  with  the  corrective  action  program  to  date  (as

confirmed  by  the  RFAsurvey  results)  indicates  that  one-half of these

facilities  (or  one-third of the total universe) will require some type of

remedial action, based on the confirmation of a release in the RFI.



    Potential  releases  of  concern  most  often noted in RFA findings are

releases {pg 30862} to ground water and soil; of all facilities, 30 percent

have  actual  or  suspected  releases  to ground water, 34 percent to soil.

Facilities  with  confirmed  or suspected releases to surface water and air

are  less  common-17  percent and 7 percent respectively, based on the RFAs

surveyed.



    Based  on  the  results of the models used in the quantitative analysis

conducted  for  the  RIA,  approximately 31 percent (1,700 RCRA facilities)

will have ground-water contamination requiring remediation.



    5.   Qualitative   Analysis.   EPA   considered  three  strategies  for

implementing  corrective action under the HSWA mandate that permits for all

treatment,  storage,  or  disposal facilities (TSDFs) address releases from

SWMUs  to  all  environmental  media.  The  following  is a summary of each

alternative strategy.



    Strategy  1-Cleanup to background levels as soon as practicable for all

facilities.    This   strategy   represented   the   most   stringent   and

environmentally conservative option of the three. Regulations modeled after

this  approach would require complete restoration of all contamination back

to the unit boundary, as quickly as could be practicably achieved. In order

to  ensure  that  solid  waste management units would continue to meet what

would  amount  to  a  ''zero  release'' standard, extensive source controls

would  be required, perhaps often involving treatment or destruction of all

wastes that could cause future contamination.



    This strategy would, if implemented, at least theoretically achieve the

highest   degree  of  protection  to  human  health  and  the  environment.

Realistically,  however,  current  technologies cannot consistently achieve

such  a  cleanup  standard.  In  addition,  the  economic impacts of such a

regulatory approach would obviously be much greater than the other options,

and could be expected to cause substantially more owner/operators to become

insolvent,  thereby  placing  additional  demands on other funding sources,

such as State or Federal cleanup funds.

    Strategy  2-Cleanup to health-based levels, with flexibility in timing.

In broad terms, this strategy would require cleanup of releases to the unit

boundary  to  concentration  levels  safe  for lifetime human exposure. The

timing for achieving these levels would vary depending on a number of site-

specific  factors,  such  as  the  extent  and nature of the contamination,

exposure potential, availability of technologies, and other factors. Source

controls  would  be  required  in  order  to prevent further releases above

health-based levels.



    This  strategy  would  also achieve a conservative level of protection.

The  economic  impacts  of  this  strategy,  although substantial, would be

considerably smaller than for Strategy 1.



    Strategy  3-Cleanup  to  health-based  standards  only  where actual or

imminent  exposure  exists.  Under  Strategy 3, corrective actions would be

required  only  if  there  was  evidence  of actual or imminent exposure to

contaminated   media  (e.g.,  contaminated  drinking  water  wells),  above

health-based  standards. The extent of cleanup would be tied to alleviating

that  exposure;  cleanup  to the unit boundary would not be required unless

exposure  were  actually  of concern at that point. Required source control

measures  would  be  less  extensive than under Strategy 1 or 2. Protection

against   future   exposure   to   contamination   would  rely  heavily  on

institutional controls.



    This  regulatory  approach would achieve a minimum level of protection,

as  compared to the other two strategies. By allowing contaminated media to

remain  contaminated based on current exposure patterns, protection against

future  exposure  could  not  be  guaranteed. Thus, Strategy 3 is the least

protective  strategy.  This  strategy would, however, be substantially less

costly to owner/operators, relative to Strategies 1 and 2.



    Today's  proposed  rule  adopts  the  Strategy  2  approach. The Agency

believes  that  this  regulatory  strategy  provides  an optimum balance in

ensuring  a  high degree of protection of human health and the environment,

while not placing unnecessary burdens on facility owner/operators.



    It should be understood that crafting a comprehensive rulemaking within

the  broad confines of any of the three alternatives listed above would, of

necessity,  require addressing a large number of specific policy questions.

Thus,  a  variety  of specific regulatory blueprints could be created under

any  one alternative. In this regard, as noted below, we have developed two

alternatives  for  the  purpose  of  quantitative  analysis that we believe

reflect  the  bounds of flexibility of implementation afforded by this rule

This  is reflected in the rule proposed today, which is generally patterned

after  Strategy  2,  but also contains certain regulatory requirements that

could be considered in line with Strategies 1 and 3.



    6.  Description  of  Options Analyzed Quantitatively. In developing the

quantitative  analysis  for  the RIA, a similar range of regulatory options

were  assessed  as  in  the  qualitative analysis. For comparison purposes,

however,  the  analysis  also examined a ''baseline'' option-in effect, the

pre-HSWA  corrective action program. In addition, the Agency developed four

regulatory  options,  two  of  which were generally believed to reflect the

flexibility  inherent in the proposed rule. It should also be noted that in

structuring  the modeling logic for this analysis, it was necessary to make

certain  assumptions  and  use decision rules that vary slightly from those

used   in   the   qualitative   analysis;  however,  the  broad  regulatory

alternatives  examined  in  the  qualitative  and quantitative analyses are

generally the same.



    The  quantitative analysis examined each of the five regulatory options

in  terms  of  the following criteria: cost, protection of human health and

the    environment,    flexibility   in   implementation,   and   technical

practicability.  This  analysis  evaluates  the effects of each alternative

only as it would address contamination of ground water.

    Detailed  information  on  the  data used in this analysis, and how the

models  were  constructed, are presented in the RIA document. The following

is  a  summary  of the options modeled, and the general assumptions used in

constructing each.



    Option  1:  Baseline  (Pre-  HSWA). This option represents requirements

under   RCRA  prior  to  enactment  of  the  1984  HSWA  corrective  action

requirements  and is used as the basis for comparison of costs and benefits

of  other  options.  Only land disposal units that received hazardous waste

after  July  26,  1982,  and thus were regulated under part 264, subpart F,

were  examined. The corrective action trigger and target concentrations are

the  same,  either  the  background  concentration or a maximum contaminant

level.  (For  modeling purposes, the baseline scenario assumed that cleanup

targets  would  not  be  established  at ''alternate concentration limits''

under  subpart  F.)  Only  onsite  cleanup  within the facility boundary is

addressed.  Ground-water  removal  and  treatment, or capping, are the only

corrective action remedies considered.



    Option 2: Immediate Cleanup to Background. This option is the strictest

of  those  evaluated.  All  SWMUs, in addition to regulated subtitle C land

disposal  units,  were addressed. Any detectable release to ground water in

excess  of  background levels would trigger corrective action, and both on-

site  and off-site contamination must be cleaned up to background levels as

soon  as  practical.  For  purposes  of  this  analysis,  we  assumed  that

background  {pg  30863} contamination did not exist and, therefore, assumed

that  cleanup  to background was equivalent to cleanup to detection limits.

Source controls are required with a bias toward excavation



    Option  3:  Immediate Cleanup to Health-Based Standards. This option is

similar to the previous one in that all SWMUs are addressed, source control

remedies  such  as excavation are required, and off-site contamination must

be  addressed  as  soon  as  detected.  However, corrective action would be

triggered  only  if  concentrations  were  detected  above  a  health-based

standard, rather than above background concentrations. This option involves

a  strong preference towards source control remedies and towards cleanup of

contamination  as  quickly  as  possible.  Use  of  technical infeasibility

waivers  is very limited, even if remedies cannot reasonably be expected to

achieve  the  target.  In  addition, unlike the previous option, cleanup of

on-site  contamination  could  be deferred until facility closure, at which

point cleanup to health-based levels would be required.



    Option  4: Flexible Cleanup to Health-Based Standards. This option also

addresses  SWMUs,  and  health-based standards are used as both trigger and

target  levels.  As  in the previous option, owners and operators may defer

cleanup  of  on-site  releases  until  facility  closure.  However, in this

alternative   owners   and   operators  have  considerable  flexibility  in

identifying  corrective  action  remedies.  Here, remedies less costly than

source  control  can  be  chosen if they achieve target within a reasonable

time  frame.  As  a  decision rule to reflect the fact that the problems of

scale  and  other  technical difficulties will preclude certain remedies at

complex  sites,  remedies  that  failed  to achieve cleanup in a reasonable

period  of  time  (assumed to be about 130 years for this analysis) or that

would  be extraordinarily expensive (i.e., over $150 million) were rejected

as  ''impracticable.''  Instead.  exposure  controls  would be relied on to

prevent  risk in these cases. It is important to note that this approach is

not  intended  to  imply  that  remedies  of  this  scope  would  never  be

undertaken, or to define the limits of technical practicability.



    Option 5: Flexible Cleanup Based on Actual Exposure. This option is the

least stringent of the five. It is similar to Option 4, except that cleanup

of off-site exposure could be deferred if there is no actual human exposure

to  the  release.  If there is an off-site exposure, corrective action must

address  the  exposure.  Again,  under  this  option,  there  is a flexible

approach towards remedy selection.



    The  Agency  believes  that  options 3 and 4 provide an upper and lower

bound on the range of outcomes that may result during implementation of the

proposed  rule. This range results from the flexible nature of the proposed

rule  and  the  uncertainty about the choice of remediation measures in the

field  and  the  performance of the remedies that are selected. EPA expects

that the real effects of the rule are likely to lie somewhere between these

two options.



    7.  Results  of  Quantitative  Analysis.  The  analysis  estimated that

approximately  31  percent  of  all RCRA facilities will trigger corrective

action  in  all  the post- HSWA options analyzed, as compared to 14 percent

that  would trigger under the baseline pre-HSWA scenario. This reflects the

requirement  that  all  SWMUs, not just land disposal units, are subject to

corrective  action under post-HSWA options. Note that even in the post-HSWA

options,  approximately  two-thirds  of  the  facilities  will  not trigger

corrective action for ground water.



    It  is  important  to  note  that differences in trigger levels did not

result  in  significant  differences in the number of facilities triggering

corrective  actions.  However, differences in target levels for the various

regulatory  options  made  a  significant difference in how many corrective

actions  were  '' successful'' in achieving cleanup levels, as is discussed

later  in this section. In examining the potential benefits of the proposal

(Options  3  and  4)  as compared to other options, the Agency developed an

''effectiveness''  test  which  measures  the  degree to which a particular

option is successful in achieving its cleanup level The results of the test

demonstrate  that  Options 3 and 4 are the most successful in achieving the

cleanup  target. This analysis supports the Agency's selection of Options 3

and 4 for the proposed rule. The effectiveness test should not, however, be

viewed  as  a  measure  of  all  the  potential  benefits of remediation of

contaminated ground water.



    The  point  when  corrective action is triggered was also analyzed. The

analysis  demonstrates  that, for Option 2, in which corrective action must

begin immediately, approximately 26 percent of all existing RCRA facilities

would  initiate  corrective  action  in  the  first year of the program. In

Options  3,  4,  and 5, in which on-site corrective action can be deferred,

only about 12 percent of all facilities would initiate corrective action in

the  first  year.  The  ability  of  a facility to defer on-site corrective

actions results in lower economic impacts.



    For  those  facilities  that  trigger  corrective  action, the analysis

estimated  the  length  of  time required for a corrective action to reduce

contaminant  concentrations  below  the  target  levels at all wells within

1,500   meters   of   the  release.  Under  options  requiring  cleanup  to

health-based  levels (i e., options 3, 4, and 5), about 51 to 56 percent of

the  facilities reach cleanup targets at all well distances within 75 years

of  the initiation of corrective action. In contrast, under the two options

requiring  cleanup  to  background,  only  about  34  percent of facilities

triggering  corrective  action  are  projected to achieve targets within 75

years.  This  further  confirms  the  presumption that achieving cleanup to

background  concentrations  may  be  difficult  or  impossible  to  achieve

technically.



    As part of the quantitative analysis, the Agency developed estimates of

the  costs  of  corrective  action  under different regulatory options on a

per-facility  basis,  as  well  as  on  a  national basis. Typical facility

corrective  action  costs  vary  significantly  depending upon the specific

regulatory  option.  The cost analysis demonstrates that the most stringent

post-HSWA  regulatory  option,  (i.e.,  Option 2, or ''Immediate Cleanup to

Background'')  is  by far the most costly option, with a mean present value

cost of over $281 million per facility, and an annualized per facility cost

of about $19 million (at a 3 percent discount rate).



    The   upper   bound   proposed  rule  option,  ''Immediate  Cleanup  to

Health-Based  Standards''  option (i.e., Option 3), was estimated to have a

mean  present  value per facility cost of $26.9 million, and annualized per

facility  costs  of  $1.8 million. The lower bound regulatory option (i.e.,

Option 4, or ''Flexible Cleanup to Health- Based Standards'') was estimated

to  have  a  mean  present  value  cost  per  facility of $6.3 million, and

annualized per facility costs of $0.4 million.



    The  baseline  per-facility  cost is the lowest of all the options at a

mean  present  value  cost  of $3.8 million, and an annualized per-facility

cost  of  $0.3  million.  The ''Flexible Cleanup Based on Actual Exposure''

option  (i.e., Option 5) was estimated to have a mean present value cost of

$4.8 million and annualized per facility costs of $0.3 million.



    The  total  national  cost  for  EPA's  corrective  action  program  is

influenced by three parameters: The average cost of each action, the number

of  facilities  required  to  undertake  corrective action, and the cost to

facility  owners  and  operators  of  undertaking  required investigations.

National  costs  discussed  below  are  presented in incremental {pg 30864}

terms (i.e., after subtracting the costs of the baseline scenario).



    The  ''Immediate  Cleanup to Background'' option is the most expensive,

with an incremental total cost above the baseline pre-HSWA scenario of $490

billion.  This  option  was  estimated  to have an annualized cost of $32.9

billion.

    Among  the  other  regulatory  options,  the  differences  in costs are

primarily  a  result  of  differences  in  timing  of  cleanup  and  in the

flexibility  afforded  in  terms  of  choosing  corrective action remedies.

Option  3  (i.  e.,  ''Immediate  Cleanup  to Health-Based Standards'') was

estimated at a total cost of $41.8 billion, with an annualized cost of $2.8

billion.  This  option  is  relatively  costly,  due  in  part  to modeling

assumptions as to the types of remedial technologies that would be employed

to meet these standards.



    Option  4  (i.e.,  ''Flexible  Cleanup to Health-Based Standards'') was

among  the  least  costly,  with  a  total  cost  of  $7.4  billion, and an

annualized  cost  of $0.5 billion. The costs are lower because, in general,

less  expensive  technologies  are  assumed and, for many facilities, final

cleanup  of  contaminated  ground  water  would be deferred for a number of

years, thus reducing the present value costs.



    Option  5  (i.e., ''Flexible Cleanup Based on Actual Exposure''), where

both  on-site and off-site cleanup of contamination could be deferred until

closure  if  there was no actual exposure, was somewhat less expensive than

the  above  option.  This  option  had  a  total  cost  of $5.0 billion, an

annualized cost of $0.3 billion.

    Today's  proposed  regulation  is  most  similar  to  Option  3  (i.e.,

''Immediate   Cleanup   to  Health-Based  Levels'')  and  Option  4  (i.e.,

''Flexible  Cleanup  to Health-Based Standards''). These results illustrate

that  the  total national costs of this rule are likely to range between $7

and  $42  billion.  The relatively wide range reflects the uncertainty in a

number  of  areas,  such  as  the timing of corrective action, the types of

remedial measures that will be considered, and the nature and difficulty of

remedial measures that are selected. Overall, the Agency believes that this

range  represents  a reasonable bound of the potential effects of the rule,

and  that  in all likelihood, the actual effects will fall somewhere within

this range.



    The  Agency  is  committed  to  trying  to refine these costs estimates

before  promulgation  of the final rule. To help in this effort, the Agency

requests  that  commenters  provide any data or information relevant to the

analysis described in the preamble or in the accompanying Regulatory Impact

Analysis.



    8.  Economic  Impacts.  With  the  cost  information developed from the

quantitative  analysis,  the  RIA  estimated  the  financial impacts of the

proposed  rule  on  affected  firms.  The results are expressed in terms of

predictions  of total costs that facility owners and operators would not be

able  to  cover due to insolvency. The results provide an indication of the

magnitude  of  costs  that could ultimately be faced by entities other than

the  immediate owner or operator of the facility. Alternate funding sources

might  include  the Superfund (provided that the facility would be eligible

for  Superfund  funding), State remedial action funds, corporate parents of

facility  owners  and operators, or, through price increases, the customers

of  the firm owning or operating the facility. The results of this analysis

are  presented  in  ''undiscounted''  numbers,  since  Superfund monies are

generally  described  in  undiscounted  terms.  For  scenarios  other  than

baseline,  costs  are  presented  on  an  incremental basis relative to the

baseline.



    Under  the  baseline  scenario,  it was estimated that 9 percent of all

firms  owning  RCRA  facilities would be adversely affected, creating total

unfunded costs of $97 million (undiscounted) over the next 50 years.



    The  ''Immediate  Cleanup to Background'' scenario generated by far the

highest  level  of  unfunded  costs,  totaling $74 billion over the next 50

years.  The  ''Immediate Cleanup to Health-Based Standards'' option results

in  unfunded  costs  of  over  $5.1  billion  over  the  next 50 years. The

''Flexible  Cleanup  to Health-Based Standards'' option results in unfunded

costs  of  over $0.5 billion over the next 50 years. The ''Flexible Cleanup

Based  on  Actual  Exposure''  option  resulted  in a total of $0.2 billion

unfunded costs, undiscounted, over the next 50 years.



    Based  on  the  RIA  analysis, EPA anticipates that the ability to fund

corrective  action  costs will vary between industries. Industries that may

have  a  relatively  low  ability  to  pay  for  corrective actions include

sanitary   services;   coating,   engraving,   and   allied  services;  and

miscellaneous  wood  products.  These  industries  have  relatively low net

income  levels.  Industries  that  show  a particularly high ability to pay

include petroleum refining, motor vehicles and motor vehicle equipment, and

aircraft and aircraft parts.



    9.  Federal  Facilities.  The  RIA  discusses  Federal  facilities as a

separate  entity  because,  although  they only constitute 6 percent of the

total RCRA facility universe, they contain many more SWMUs per facility (on

average,  55  per  site)  and therefore, may incur higher corrective action

costs. These costs must be funded by public money.



    Based on the RIA analysis, it is estimated that of the 352 Federal RCRA

facilities,  between  61  percent  and  100  percent  are likely to require

ground-  water  corrective  action  under  the  proposed  rule, compared to

between  17 percent and 23 percent under the baseline A rough approximation

of  the  costs  for these corrective actions, per facility, ranges from $17

million  for  the  baseline  scenario  to  $1.3 billion for the ''Immediate

Cleanup  to  Background''  option.  For  the  options  most  similar to the

proposed  rule  (i.e., ''Immediate Cleanup to Health- Based Standards'' and

''Flexible  Cleanup to Health-Based Standards'') the mean per facility cost

is  estimated  to  range  from $123 to $29 million, or in annualized costs,

from about $8 to $2 million per facility.



    The  total Federal facility costs, incremental to the baseline, for the

options  most  similar  to  the  proposal range from $3 to $18 billion; the

annualized  costs  range  from  $0.2  to  $1.1  billion.  Again, this range

reflects  the likely bounds on the ways in which the RCRA corrective action

program  will ultimately be implemented for Federal facilities. Incremental

Federal  facility  costs  for  other  regulatory  approaches  could be $208

billion  for  the ''Immediate Cleanup to Background'' option, or $2 billion

for  the  ''Flexible  Cleanup  Based  on Actual Exposure'' option. Baseline

costs are estimated to be $1 billion.



    This  analysis  thus  concludes  that, although Federal facilities only

comprise  6  percent  of  the  population affected by the corrective action

program, they could incur roughly 30 percent of the total cost of the rule.

    10.  Further  Regulatory Impact Analyses. Given the scope and potential

impacts  of  this rulemaking, EPA recognizes the need to continue to refine

its  estimates of the costs and benefits of the rule. The Agency intends to

collect  additional data and will conduct substantial new analyses prior to

finalizing  today's  rule. In conducting these studies, the Agency believes

that  it  will  be  of particular value to examine the experience gained in

recent   years   in   remediating  Federal  facilities.  Large  volumes  of

information  and  extensive  technical  experience  have  been  accumulated

specifically by the Department of Defense and the Department of Energy. EPA

intends  to  form an interagency working group to develop and conduct these

further Regulatory Impact Analyses.



    The  new  analyses  will  be  conducted in accordance with the existing

Agency  guidance  on  Regulatory  Impact  Analysis and the draft Regulatory

Impact  Analysis  Guidance  published in the 1988 Regulatory Program of the

United  States.  The analyses will explicitly examine the costs, health and

environmental   benefits,   and   technological  limitations  for  the  key

regulatory  requirements  contained  in  the  proposal-especially  for  the

several  alternative approaches to ground water remediation outlined in the

proposed  rule.  This  analysis  will  also estimate the aggregate impacts,

identified  above,  for  sites eligible for remediation under this rule and

for  those  sites which are listed on the NPL, and will, therefore, look to

this  rule  as  an ARAR, under the provisions of CERCLA. Upon completion of

the  revised  analyses,  EPA  will  solicit  comment  on the results of the

analyses  and  the  methodology  used  to derive them. The Agency will then

assess  these  comments,  along with comments which will have been received

previously on the proposed rule. Through these actions EPA will ensure that

the  net  social  benefits (including environmental and health benefits) of

the   rule  proposed  today  are  maximized,  taking  into  account  costs,

technological  limitations, risks, and realistic assessments of both actual

and  reasonably  expected  uses  of each site. If the revised RIA, together

with  the  comments received, demonstrate that the rule proposed today does

not achieve this outcome, the Agency will make appropriate modifications to

the final rule, or if necessary, will repropose the rule.



B. Regulatory Flexibility Act



    The  Regulatory  Flexibility  Act  requires  Federal  agencies to fully

analyze  the  economic effects of regulations on small entities. The Agency

analyzed  the  economic  impacts  for  the regulatory options that are most

similar to today's proposed rule (i.e., ''Immediate Cleanup to Health-Based

Standards'' and ''Flexible Cleanup to Health-Based Standards'').



    The  RIA assumes that a small business is significantly impacted if its

excess  of  cash  flow  over  ten  percent  of  its  total  liabilities  is

insufficient  to  meet  corrective  action  costs,  or if its net income is

insufficient to meet its corrective action costs.



    For  the  alternative analyzed, it was found that small firms encounter

more  severe  impacts  from  the  corrective action requirements than large

firms.  The options most similar to the proposed rule result in incremental

impacts  (i.e.,  relative to the baseline) on approximately 9 to 11 percent

of small businesses owning RCRA facilities.



    Based  on  the  Agency's  guidelines  for  implementing  the Regulatory

Feasibility  Act,  the results of the analysis as summarized above, suggest

that  the  proposed  rule  does  not  impose  significant  impacts on small

entities.



C. Paperwork Reduction Act



    The information collection requirements in this proposed rule have been

submitted  for  approval to the Office of Management and Budget (OMB) under

the  Paperwork  Reduction  Act,  44  U.S.C.  3501  et  seq.  Reporting  and

recordkeeping  burden  on  the  public  for this collection is estimated at

42,497  hours  for  the 674 respondents, with an average of 1.151 hours per

response.  (Burden  estimates  should include all aspects of the collection

effort  and may include time for reviewing instructions, searching existing

data  sources,  gathering  and  maintaining the data needed, completing and

reviewing the collection of information. etc.)



    If  you  wish to submit comments regarding any aspect of the collection

of  information,  including  suggestions for reducing the burden, or if you

would  like  a copy of the information collection request (please reference

ICR  1451),  contact Rick Westlund, Information Policy Branch, PM-223, U.S.

Environmental  Protection  Agency,  401 M Street, SW., Washington, DC 20460

(202-382-2745); and Tim Hunt, Office of Information and Regulatory Affairs,

Office  of Management and Budget, Washington, DC 20503. The final rule will

respond  to  any  OMB  or  public  comments  on  the information collection

requirements contained in this proposal.



List of Subjects in 40 CFR Parts 264, 265, 270, and 271



    Administrative  practice  and  procedure,  Corrective action, Hazardous

waste; Insurance, Reporting and recordkeeping requirements.



    Dated: July 5, 1990.

William Reilly,



Administrator.



XI. Supplementary Documents



 Appendix A.-Examples of Concentrations Meeting Criteria for

                  Action Levels

            Section 264.521(a)(2)(i-iv)



 Constituent name       Acetone

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-00

 Soils (mg/kg)          8E+03



 Constituent name       Acetonitrile

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          5E+02

 Constituent name       Acetophenone

 Class                  D

 Air (ug/m sup 7:3)     2E-01

 Water (mg/L)           4E-00

 Soils (mg/kg)          8E+03



 Constituent name       Acrylamide

 Class                  B2

 Air (ug/m sup 7:3)     8E-04

 Water (mg/L)           8E-06

 Soils (mg/kg)          2E-01



 Constituent name       Acrylonitrile

 Class                  B1

 Air (ug/m sup 7:3)     1E-02

 Water (mg/L)           6E-05

 Soils (mg/kg)          1E-00



 Constituent name       Aldicarb

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           5E-02

 Soils (mg/kg)          1E+02



 Constituent name       Aldrin

 Class                  B2

 Air (ug/m sup 7:3)     2E-04

 Water (mg/L)           2E-06

 Soils (mg/kg)          4E-02



 Constituent name       Allyl alcohol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          4E+02



 Constituent name       Aluminum phosphide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-02

 Soils (mg/kg)          3E+01



 Constituent name       Aniline

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           6E-03

 Soils (mg/kg)          1E+02



 Constituent name       Antimony

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-02

 Soils (mg/kg)          3E+01



 Constituent name       Arsenic

 Class                  A

 Air (ug/m sup 7:3)     7E-05

 Water (mg/L)           (1)

 Soils (mg/kg)          8E+01



 Constituent name       Asbestos (2)

 Class                  A

 Air (ug/m sup 7:3)     2E-02

 Water (mg/L)

 Soils (mg/kg)

 Constituent name       Barium cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-00

 Soils (mg/kg)          6E+03



 Constituent name       Barium, ionic

 Class                  D

 Air (ug/m sup 7:3)     4E-01

 Water (mg/L)           (1)

 Soils (mg/kg)          4E+03



 Constituent name       Benzidine

 Class                  A

 Air (ug/m sup 7:3)     2E-05

 Water (mg/L)           2E-07

 Soils (mg/kg)          3E-03



 Constituent name       Beryllium

 Class                  B2

 Air (ug/m sup 7:3)     4E-04

 Water (mg/L)           8E-06

 Soils (mg/kg)          2E-01



 Constituent name       Bis(2-ethylhexyl)phthlate

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-03

 Soils (mg/kg)          5E+01



 Constituent name       Bis(chloroethyl)ether

 Class                  B2

 Air (ug/m sup 7:3)     3E-03

 Water (mg/L)           3E-05

 Soils (mg/kg)          6E-01



 Constituent name       Bromodichloromethane (3)

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-05

 Soils (mg/kg)          5E-01



 Constituent name       Bromoform (3)

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-01

 Soils (mg/kg)          2E+03



 Constituent name       Bromomethane

 Class                  D

 Air (ug/m sup 7:3)     3E+01

 Water (mg/L)           5E-02

 Soils (mg/kg)          1E+02



 Constituent name       Butyl benzyl phthalate

 Class                  C

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-00

 Soils (mg/kg)          2E+04



 Constituent name       Cadmium

 Class                  B1

 Air (ug/m sup 7:3)     6E-04

 Water (mg/L)           (1)

 Soils (mg/kg)          4E+01

 Constituent name       Calcium cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-00

 Soils (mg/kg)          3E+03



 Constituent name       Carbon disulfide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-00

 Soils (mg/kg)          8E+03



 Constituent name       Carbon tetrachloride

 Class                  B2

 Air (ug/m sup 7:3)     3E-02

 Water (mg/L)           3E-04

 Soils (mg/kg)          5E-00



 Constituent name       Chloral

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-02

 Soils (mg/kg)          2E+02



 Constituent name       Chlordane

 Class                  B2

 Air (ug/m sup 7:3)     3E-03

 Water (mg/L)           3E-05

 Soils (mg/kg)          5E-01



 Constituent name       Chlorine cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-00

 Soils (mg/kg)          4E+03



 Constituent name       Chlorobenzene

 Class                  D

 Air (ug/m sup 7:3)     2E+01

 Water (mg/L)           7E-01

 Soils (mg/kg)          2E+03



 Constituent name       Chloroform (3)

 Class                  B2

 Air (ug/m sup 7:3)     4E-02

 Water (mg/L)           6E-03

 Soils (mg/kg)          1E+02



 Constituent name       2-Chlorophenol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          4E+02



 Constituent name       Chromium (VI)

 Class                  A

 Air (ug/m sup 7:3)     9E-05

 Water (mg/L)           (1)

 Soils (mg/kg)          4E+02



 Constituent name       Copper cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          4E+02

 Constituent name       m-Cresol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-00

 Soils (mg/kg)          4E+03



 Constituent name       o-Cresol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-00

 Soils (mg/kg)          4E+03



 Constituent name       p-Cresol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-00

 Soils (mg/kg)          40+03



 Constituent name       Cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-01

 Soils (mg/kg)          2E+03



 Constituent name       Cyanogen

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-00

 Soils (mg/kg)          3E+03



 Constituent name       Cyanogen bromide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-00

 Soils (mg/kg)          7E+03



 Constituent name       DDD

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-04

 Soils (mg/kg)          3E-00



 Constituent name       DDE

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-04

 Soils (mg/kg)          2E-00



 Constituent name       DDT

 Class                  B2

 Air (ug/m sup 7:3)     1E-02

 Water (mg/L)           1E-04

 Soils (mg/kg)          2E-00



 Constituent name       Dibutyl phthalate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-00

 Soils (mg/kg)          8E+03



 Constituent name       Dibutylnitrosamine

 Class                  B2

 Air (ug/m sup 7:3)     6E-04

 Water (mg/L)           6E-06

 Soils (mg/kg)          1E-01

 Constituent name       3,3'-Dichlorobenzidine

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           8E-05

 Soils (mg/kg)          2E-00



 Constituent name       Dichlorodiffluoromethane

 Class                  D

 Air (ug/m sup 7:3)     2E+02

 Water (mg/L)           7E-00

 Soils (mg/kg)          2E+04



 Constituent name       1,2-Dichloroethane

 Class                  B2

 Air (ug/m sup 7:3)     4E-02

 Water (mg/L)           (1)

 Soils (mg/kg)          8E-00



 Constituent name       1,1-Dichloroethylene

 Class                  C

 Air (ug/m sup 7:3)     3E-02

 Water (mg/L)           (1)

 Soils (mg/kg)          1E+01



 Constituent name       2,4-Dichlorophenol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-01

 Soils (mg/kg)          2E+02



 Constituent name       2,4-Dichlorophenoxyacetic acid

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-01

 Soils (mg/kg)          8E+02



 Constituent name       1,3-Dichloropropene

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-02

 Soils (mg/kg)          2E+01



 Constituent name       Dieldrin

 Class                  B2

 Air (ug/m sup 7:3)     2E-04

 Water (mg/L)           2E-06

 Soils (mg/kg)          4E-02



 Constituent name       Diethyl phthalate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E+01

 Soils (mg/kg)          6E+04



 Constituent name       Diethylnitrosamine

 Class                  B2

 Air (ug/m sup 7:3)     2E-05

 Water (mg/L)           2E-07

 Soils (mg/kg)          5E-03



 Constituent name       Dimethoate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-01

 Soils (mg/kg)          2E+03

 Constituent name       Dimethylnitrosamine

 Class                  B2

 Air (ug/m sup 7:3)     7E-05

 Water (mg/L)           7E-07

 Soils (mg/kg)          1E-02



 Constituent name       m-Dinitrobenzene

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-03

 Soils (mg/kg)          8E-00



 Constituent name       2,4-Dinitrophenol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-02

 Soils (mg/kg)          2E+02



 Constituent name       2,3-Dinitrotoluene (and 2,6-, mixture)

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           5E-05

 Soils (mg/kg)          1E-00



 Constituent name       1,4-Dioxane

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-03

 Soils (mg/kg)          6E+01



 Constituent name       Diphenylamine

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           9E-01

 Soils (mg/kg)          2E+03



 Constituent name       1,2-Diphenylhydrazine

 Class                  B2

 Air (ug/m sup 7:3)     4E-03

 Water (mg/L)           4E-05

 Soils (mg/kg)          9E-01



 Constituent name       Disulfoton

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-03

 Soils (mg/kg)          3E-00



 Constituent name       Endosulfan

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-03

 Soils (mg/kg)          4E-00



 Constituent name       Endothall

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-01

 Soils (mg/kg)          2E+03



 Constituent name       Endrin

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           (1)

 Soils (mg/kg)          2E+01

 Constituent name       Epichlorohydrin

 Class                  B2

 Air (ug/m sup 7:3)     8E-01

 Water (mg/L)           4E-03

 Soils (mg/kg)          7E+01



 Constituent name       Ethylbenzene

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-00

 Soils (mg/kg)          8E+03



 Constituent name       Ethylene dibromide

 Class                  B2

 Air (ug/m sup 7:3)     5E-03

 Water (mg/L)           4E-07

 Soils (mg/kg)          8E-03



 Constituent name       Formaldehyde

 Class                  B1

 Air (ug/m sup 7:3)     8E-02

 Water (mg/L)

 Soils (mg/kg)



 Constituent name       Formic acid

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E+01

 Soils (mg/kg)          2E+05



 Constituent name       Glycidyaldehyde

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-02

 Soils (mg/kg)          3E+01



 Constituent name       Heptachlor

 Class                  B2

 Air (ug/m sup 7:3)     8E-04

 Water (mg/L)           8E-06

 Soils (mg/kg)          2E-01



 Constituent name       Heptachlor epoxide

 Class                  B2

 Air (ug/m sup 7:3)     4E-04

 Water (mg/L)           4E-06

 Soils (mg/kg)          8E-02



 Constituent name       Hexachlordibenzo-p-dioxin

 Class                  B2

 Air (ug/m sup 7:3)     6E-07

 Water (mg/L)           1E-08

 Soils (mg/kg)          1E-04



 Constituent name       Hexachlorobutadiene

 Class                  C

 Air (ug/m sup 7:3)     4E-01

 Water (mg/L)           4E-03

 Soils (mg/kg)          9E+01



 Constituent name       alpha-Hexachlorocyclohexane

 Class                  B2

 Air (ug/m sup 7:3)     6E-04

 Water (mg/L)           6E-06

 Soils (mg/kg)          1E-01

 Constituent name       beta-Hexachlorocyclohexane

 Class                  C

 Air (ug/m sup 7:3)     2E-02

 Water (mg/L)           2E-04

 Soils (mg/kg)          4E-00



 Constituent name       Hexachlorocyclopentadiene

 Class                  D

 Air (ug/m sup 7:3)     7E-02

 Water (mg/L)           2E-01

 Soils (mg/kg)          6E+02



 Constituent name       Hexachloroethane

 Class                  C

 Air (ug/m sup 7:3)     3E-00

 Water (mg/L)           3E-02

 Soils (mg/kg)          8E+01



 Constituent name       Hexachlorophene

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-02

 Soils (mg/kg)          2E+01



 Constituent name       Hydrazine

 Class                  B2

 Air (ug/m sup 7:3)     2E-04

 Water (mg/L)           1E-05

 Soils (mg/kg)          2E-01



 Constituent name       Hydrogen cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-01

 Soils (mg/kg)          2E+03



 Constituent name       Hydrogen sulfite

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-01

 Soils (mg/kg)          2E+02



 Constituent name       Isobutyl alcohol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E+01

 Soils (mg/kg)          2E+04



 Constituent name       Isophorone

 Class                  C

 Air (ug/m sup 7:3)

 Water (mg/L)           9E-02

 Soils (mg/kg)          2E+03



 Constituent name       Lead

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           (1)

 Soils (mg/kg)



 Constituent name       Lindane (gamma-hexachlorocyclohexane)

 Class                  B2/C

 Air (ug/m sup 7:3)

 Water (mg/L)           (1)

 Soils (mg/kg)          5E-01

 Constituent name       m-Phenylenediamine

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          5E+02



 Constituent name       Maleic anhydride

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-00

 Soils (mg/kg)          8E+03



 Constituent name       Maleic hydrazide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E+01

 Soils (mg/kg)          4E+04



 Constituent name       Mercury (inorganic)

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           (1)

 Soils (mg/kg)          2E+01



 Constituent name       Methacrylonitrile

 Class                  D

 Air (ug/m sup 7:3)     7E-01

 Water (mg/L)           4E-03

 Soils (mg/kg)          8E-00



 Constituent name       Methomyl

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           9E-01

 Soils (mg/kg)          2E+03



 Constituent name       Methyl chlorocarbonate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)

 Soils (mg/kg)



 Constituent name       Methyl ethyl ketone

 Class                  D

 Air (ug/m sup 7:3)     3E+02

 Water (mg/L)           2E-00

 Soils (mg/kg)          4E+03



 Constituent name       Methyl isobutyl ketone

 Class                  D

 Air (ug/m sup 7:3)     7E+01

 Water (mg/L)           2E-00

 Soils (mg/kg)          4E+03



 Constituent name       Methyl parathion

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           9E-03

 Soils (mg/kg)          2E+01



 Constituent name       Methylene chloride

 Class                  B

 Air (ug/m sup 7:3)     3E-01

 Water (mg/L)           5E-03

 Soils (mg/kg)          9E+01

 Constituent name       n-Nitroso-di-n-butylamine

 Class                  B2

 Air (ug/m sup 7:3)     6E-04

 Water (mg/L)           6E-06

 Soils (mg/kg)          1E-01



 Constituent name       n-Nitroso-n-ethylurea

 Class                  B

 Air (ug/m sup 7:3)

 Water (mg/L)

 Soils (mg/kg)



 Constituent name       n-Nitroso-n-methylethylamine

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-06

 Soils (mg/kg)          3E-02



 Constituent name       n-Nitrosodi-n-propylamine

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           5E-06

 Soils (mg/kg)          1E-01



 Constituent name       n-Nitrosodiethanolamine

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-05

 Soils (mg/kg)          3E-01



 Constituent name       n-Nitrosodiphenylamine

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-03

 Soils (mg/kg)          1E+02



 Constituent name       n-Nitrosopyrrolidine

 Class                  B2

 Air (ug/m sup 7:3)     2E-03

 Water (mg/L)           2E-05

 Soils (mg/kg)          3E-01



 Constituent name       Nickel

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-01

 Soils (mg/kg)          2E+03



 Constituent name       Nickel refinery dust

 Class                  A

 Air (ug/m sup 7:3)     4E-03

 Water (mg/L)

 Soils (mg/kg)



 Constituent name       Nitric oxide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-00

 Soils (mg/kg)          8E+03



 Constituent name       Nitrobenzene

 Class                  D

 Air (ug/m sup 7:3)     2E-00

 Water (mg/L)           2E-02

 Soils (mg/kg)          4E+01

 Constituent name       Nitrogen dioxide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E+01

 Soils (mg/kg)          8E+04



 Constituent name       Osmium tetroxide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-04

 Soils (mg/kg)          8E-01



 Constituent name       Parathion

 Class                  C

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          5E+02



 Constituent name       Pentachlorobenzene

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-02

 Soils (mg/kg)          6E+01



 Constituent name       Pentachloronitrobenzene

 Class                  C

 Air (ug/m sup 7:3)     1E-01

 Water (mg/L)           1E-01

 Soils (mg/kg)          2E+02



 Constituent name       Pentachlorophenol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-00

 Soils (mg/kg)          2E+03



 Constituent name       Phenol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E+01

 Soils (mg/kg)          5E+04



 Constituent name       Phenyl mercuric acetate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-03

 Soils (mg/kg)          6E-00



 Constituent name       Phosphine

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-02

 Soils (mg/kg)          2E+01



 Constituent name       Phthalic anhydride

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E+01

 Soils (mg/kg)          2E+05



 Constituent name       Polychlorinated biphenyls

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           5E-06

 Soils (mg/kg)          9E-02

 Constituent name       Potassium cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-00

 Soils (mg/kg)          4E+03



 Constituent name       Potassium silver cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-00

 Soils (mg/kg)          2E+04



 Constituent name       Pronamide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-00

 Soils (mg/kg)          6E+03



 Constituent name       Pyridine

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-02

 Soils (mg/kg)          8E+01



 Constituent name       Selenious acid

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-01

 Soils (mg/kg)          2E+02



 Constituent name       Selenourea

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          4E+02



 Constituent name       Silver

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           (1)

 Soils (mg/kg)          2E+02



 Constituent name       Silver cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-00

 Soils (mg/kg)          8E+03



 Constituent name       Sodium cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-00

 Soils (mg/kg)          3E+03



 Constituent name       Strychnine

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-02

 Soils (mg/kg)          2E+01



 Constituent name       Styrene

 Class                  C

 Air (ug/m sup 7:3)

 Water (mg/L)           7E-00

 Soils (mg/kg)          2E+04

 Constituent name       1,1,1,2-Tetrachlorethane

 Class                  C

 Air (ug/m sup 7:3)     1E-00

 Water (mg/L)           1E-02

 Soils (mg/kg)          3E+02



 Constituent name       1,2,4,5-Tetrachlorobenzene

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-02

 Soils (mg/kg)          2E+01



 Constituent name       1,1,1,2-Tetrachloroethane

 Class                  C

 Air (ug/m sup 7:3)     1E-00

 Water (mg/L)           1E-02

 Soils (mg/kg)          3E+02



 Constituent name       1,1,2,2-Tetrachloroethane

 Class                  C

 Air (ug/m sup 7:3)     2E-01

 Water (mg/L)           2E-03

 Soils (mg/kg)          4E+01



 Constituent name       Tetrachloroethylene

 Class                  B2

 Air (ug/m sup 7:3)     1E-00

 Water (mg/L)           7E-04

 Soils (mg/kg)          1E+01



 Constituent name       2,3,4,6-Tetrachlorophenol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-00

 Soils (mg/kg)          2E+03



 Constituent name       Tetraethyl lead

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-06

 Soils (mg/kg)          8E-03



 Constituent name       Tetraethyldithiopyrophosphate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-02

 Soils (mg/kg)          4E+01



 Constituent name       Thallic oxide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-03

 Soils (mg/kg)          6E-00



 Constituent name       Thallium acetate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-03

 Soils (mg/kg)          7E-00



 Constituent name       Thallium carbonate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-03

 Soils (mg/kg)          6E-00

 Constituent name       Thallium chloride

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-03

 Soils (mg/kg)          6E-00



 Constituent name       Thallium nitrate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-03

 Soils (mg/kg)          7E-00



 Constituent name       Thallium sulfate

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-03

 Soils (mg/kg)          6E-00



 Constituent name       Thiosemicarbazide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          5E+02



 Constituent name       Thiram

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          4E+02



 Constituent name       Toluene

 Class                  D

 Air (ug/m sup 7:3)     7E+03

 Water (mg/L)           1E+01

 Soils (mg/kg)          2E+04



 Constituent name       Toxaphene

 Class                  B2

 Air (ug/m sup 7:3)     3E-03

 Water (mg/L)           (1)

 Soils (mg/kg)          6E-01



 Constituent name       1,2,4-Trichlorobenzene

 Class                  D

 Air (ug/m sup 7:3)     1E+01

 Water (mg/L)           7E-01

 Soils (mg/kg)          2E+03



 Constituent name       1,1,1-Trichloroethane

 Class                  D

 Air (ug/m sup 7:3)     1E+03

 Water (mg/L)

 Constituent name       1,1,2-Trichloroethane

 Class                  C

 Air (ug/m sup 7:3)     6E-01

 Water (mg/L)           6E-03

 Soils (mg/kg)          1E+02



 Constituent name       Trichloroethylene

 Class                  B2

 Air (ug/m sup 7:3)

 Water (mg/L)           (1)

 Soils (mg/kg)          6E+01



 Constituent name       Trichloromonofluoromethane

 Class                  D

 Air (ug/m sup 7:3)     7E+02

 Water (mg/L)           1E+01

 Soils (mg/kg)          2E+04



 Constituent name       2,4,5-Trichlorophenol

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           4E-00

 Soils (mg/kg)          8E+03



 Constituent name       2,4,6-Trichlorophenol

 Class                  B2

 Air (ug/m sup 7:3)     2E-01

 Water (mg/L)           2E-03

 Soils (mg/kg)          4E+01



 Constituent name       2,4,5-Trichlorophenoxyacetic acid

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           (1)

 Soils (mg/kg)          8E+02

 Constituent name       1,2,3-Trichloropropane

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-01

 Soils (mg/kg)          5E+02



 Constituent name       Vanadium pentoxide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           3E-01

 Soils (mg/kg)          7E+02



 Constituent name       Xylenes

 Class                  D

 Air (ug/m sup 7:3)     1E+03

 Water (mg/L)           7E+01

 Soils (mg/kg)          2E+05



 Constituent name       Zinc cyanide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           2E-00

 Soils (mg/kg)          4E+03



 Constituent name       Zinc phosphide

 Class                  D

 Air (ug/m sup 7:3)

 Water (mg/L)           1E-02

 Soils (mg/kg)          2E+01



 (1) MCL available; see appendix B.



 (2) The air action level for asbestos is measured in units of

 fibers/mililiters.



 (3) There is an MCL for total trihalomethanes, which includes

 four constituents: bromoform, bromodichloromethane, chloroform,

 and dibromochloromethane. Concentration derived using exposure

 assumptions in appendix D and reference doses for systemic

 toxicants and verified risk-specific doses at 10-6 for Class A

 and B carcinogens and 10-5 for Class C carcinogens (see section

 VI.F.2.6 for further discussion).



 A, B and C represents class A, B and C carcinogens, respectively;

 D represents a systemic toxicant.







 Appendix B-Maximum Contaminant Levels



 Constituent     Arsenic

 MCL (ppm)       0.05



 Constituent     Barium

 MCL (ppm)       1



 Constituent     Benzene

 MCL (ppm)       0.005



 Constituent     Cadmium

 MCL (ppm)       0.010



 Constituent     Carbon tetrachloride

 MCL (ppm)       0.005



 Constituent     Chromium VI

 MCL (ppm)       0.05



 Constituent     p-Dichlorobenzene

 MCL (ppm)       0.075



 Constituent     1,2-Dichloroethane

 MCL (ppm)       0.005



 Constituent     1,1-Dichloroethylene

 MCL (ppm)       0.007



 Constituent     2,4-D

 MCL (ppm)       0.1



 Constituent     2,4,5-TP Silvex

 MCL (ppm)       0.01



 Constituent     Endrin

 MCL (ppm)       0.0002



 Constituent     Fluoride

 MCL (ppm)       4.0



 Constituent     Lead

 MCL (ppm)       0.05



 Constituent     Lindane

 MCL (ppm)       0.004



 Constituent     Mercury

 MCL (ppm)       0.002



 Constituent     Methoxychlor

 MCL (ppm)       0.1



 Constituent     Nitrate

 MCL (ppm)       10



 Constituent     Selenium

 MCL (ppm)       0.01



 Constituent     Silver

 MCL (ppm)       0.05

 Constituent     Toxaphene

 MCL (ppm)       0.005



 Constituent     1,1,1-Trichloroethane

 MCL (ppm)       0.2



 Constituent     Trichloroethylene

 MCL (ppm)       0.005



 Constituent     Trihalomethanes, total fn 1

 MCL (ppm)       0.10



 Constituent     Vinyl chloride

 MCL (ppm)       0.002



 fn 1 Including chloroform, bromoform, bromodichloromethane, and

 dibromochloromethane







 Appendix C-Range of Concentrations for Establishing Media

        Protection Standards for Carcinogens



 Constituent name       Acetone

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Acetonitrile

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Acetophenone

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Acrylamide

 Class                  B2

 MaxAir (ug/m 3)        8E-02

 MinAir (ug/m 3)        8E-04

 MaxWater (mg/L)        8E-04

 MinWater (mg/L)        8E-06

 MaxSoil (mg/kg)        2E+01

 MinSoil (mg/kg)        2E-01



 Constituent name       Acrylonitrile

 Class                  B1

 MaxAir (ug/m 3)        1E-00

 MinAir (ug/m 3)        1E-02

 MaxWater (mg/L)        6E-03

 MinWater (mg/L)        6E-05

 MaxSoil (mg/kg)        1E+02

 MinSoil (mg/kg)        1E-00



 Constituent name       Aldicarb

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Aldrin

 Class                  B2

 MaxAir (ug/m 3)        2E-02

 MinAir (ug/m 3)        2E-04

 MaxWater (mg/L)        2E-04

 MinWater (mg/L)        2E-06

 MaxSoil (mg/kg)        4E-00

 MinSoil (mg/kg)        4E-02



 Constituent name       Allyl alcohol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Aluminum phosphide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Aniline

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        6E-01

 MinWater (mg/L)        6E-03

 MaxSoil (mg/kg)        1E+04

 MinSoil (mg/kg)        1E+02



 Constituent name       Antimony

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Arsenic

 Class                  A

 MaxAir (ug/m 3)        7E-03

 MinAir (ug/m 3)        7E-05

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Asbestos (2)

 Class                  A

 MaxAir (ug/m 3)        2E-00

 MinAir (ug/m 3)        2E-02

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Barium cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Barium, ionic

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Benzidine

 Class                  A

 MaxAir (ug/m 3)        2E-03

 MinAir (ug/m 3)        2E-05

 MaxWater (mg/L)        2E-05

 MinWater (mg/L)        2E-07

 MaxSoil (mg/kg)        3E-01

 MinSoil (mg/kg)        3E-03



 Constituent name       Beryllium

 Class                  B2

 MaxAir (ug/m 3)        4E-02

 MinAir (ug/m 3)        4E-04

 MaxWater (mg/L)        8E-04

 MinWater (mg/L)        8E-06

 MaxSoil (mg/kg)        2E+01

 MinSoil (mg/kg)        2E-01

 Constituent name       Bis(2-ethylhexyl)phthlate

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        3E-01

 MinWater (mg/L)        3E-03

 MaxSoil (mg/kg)        5E+03

 MinSoil (mg/kg)        5E+01



 Constituent name       Bis(chloroethyl)ether

 Class                   B2

 MaxAir (ug/m 3)        3E-01

 MinAir (ug/m 3)        3E-03

 MaxWater (mg/L)        3E-03

 MinWater (mg/L)        3E-05

 MaxSoil (mg/kg)        6E+01

 MinSoil (mg/kg)        6E-01



 Constituent name       Bromodichloromethane

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        3E-03

 MinWater (mg/L)        3E-05

 MaxSoil (mg/kg)        5E+01

 MinSoil (mg/kg)        5E-01



 Constituent name       Bromoform

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Bromomethane

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Butyl benzyl phthalate

 Class                  C

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Cadmium

 Class                  B1

 MaxAir (ug/m 3)        6E-02

 MinAir (ug/m 3)        6E-04

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Calcium cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Carbon disulfide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Carbon tetrachloride

 Class                  B2

 MaxAir (ug/m 3)        3E-00

 MinAir (ug/m 3)        3E-02

 MaxWater (mg/L)        3E-02

 MinWater (mg/L)        3E-04

 MaxSoil (mg/kg)        5E+02

 MinSoil (mg/kg)        5E-00



 Constituent name       Chloral

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Chlordane

 Class                  B2

 MaxAir (ug/m 3)        3E-01

 MinAir (ug/m 3)        3E-03

 MaxWater (mg/L)        3E-03

 MinWater (mg/L)        3E-05

 MaxSoil (mg/kg)        5E+01

 MinSoil (mg/kg)        5E-01



 Constituent name       Chlorine cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Chlorobenzene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Chloroform

 Class                  B2

 MaxAir (ug/m 3)        4E-00

 MinAir (ug/m 3)        4E-02

 MaxWater (mg/L)        6E-01

 MinWater (mg/L)        6E-03

 MaxSoil (mg/kg)        1E+04

 MinSoil (mg/kg)        1E+02



 Constituent name       2-Chlorophenol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Chromium (VI)

 Class                  A

 MaxAir (ug/m 3)        9E-03

 MinAir (ug/m 3)        9E-05

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Copper cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       m-Cresol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       o-Cresol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       p-Cresol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)

 Constituent name       Cyanogen

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Cyanogen bromide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       DDD

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        1E-02

 MinWater (mg/L)        1E-04

 MaxSoil (mg/kg)        3E+02

 MinSoil (mg/kg)        3E-00



 Constituent name       DDE

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        1E-02

 MinWater (mg/L)        1E-04

 MaxSoil (mg/kg)        2E+02

 MinSoil (mg/kg)        2E-00



 Constituent name       DDT

 Class                  B2

 MaxAir (ug/m 3)        1E-00

 MinAir (ug/m 3)        1E-02

 MaxWater (mg/L)        1E-02

 MinWater (mg/L)        1E-04

 MaxSoil (mg/kg)        2E+02

 MinSoil (mg/kg)        2E-00



 Constituent name       Dibutyl phthalate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Dibutylnitrosamine

 Class                  B2

 MaxAir (ug/m 3)        6E-02

 MinAir (ug/m 3)        6E-04

 MaxWater (mg/L)        6E-04

 MinWater (mg/L)        6E-06

 MaxSoil (mg/kg)        1E+01

 MinSoil (mg/kg)        1E-01



 Constituent name       3,3'-Dichlorobenzidine

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        8E-03

 MinWater (mg/L)        8E-05

 MaxSoil (mg/kg)        2E+02

 MinSoil (mg/kg)        2E-00



 Constituent name       Dichlorodifluormethane

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       1,2-Dichloroethane

 Class                  B2

 MaxAir (ug/m 3)        4E-00

 MinAir (ug/m 3)        4E--02

 MaxWater (mg/L)        4E-02

 MinWater (mg/L)        4E-04

 MaxSoil (mg/kg)        8E+02

 MinSoil (mg/kg)        8E-00



 Constituent name       1,1-Dichlorothylene

 Class                  C

 MaxAir (ug/m 3)        3E-01

 MinAir (ug/m 3)        3E-03

 MaxWater (mg/L)        6E-03

 MinWater (mg/L)        6E-05

 MaxSoil (mg/kg)        1E+02

 MinSoil (mg/kg)        1E-00



 Constituent name       2,4-Dichlorophenol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       2,4-Dichlorophenoxyacetic acid

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       1,3-Dichloropropene

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Dieldrin

 Class                  B2

 MaxAir (ug/m 3)        2E-02

 MinAir (ug/m 3)        2E-04

 MaxWater (mg/L)        2E-04

 MinWater (mg/L)        2E-06

 MaxSoil (mg/kg)        4E-00

 MinSoil (mg/kg)        4E-02



 Constituent name       Diethyl phthalate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Diethylnitrosamine

 Class                  B2

 MaxAir (ug/m 3)        2E-03

 MinAir (ug/m 3)        2E-05

 MaxWater (mg/L)        2E-05

 MinWater (mg/L)        2E-07

 MaxSoil (mg/kg)        5E-01

 MinSoil (mg/kg)        5E-03



 Constituent name       Dimethoate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Dimethylnitrosamine

 Class                  B2

 MaxAir (ug/m 3)        7E-03

 MinAir (ug/m 3)        7E-05

 MaxWater (mg/L)        7E-05

 MinWater (mg/L)        7E-07

 MaxSoil (mg/kg)        1E-00

 MinSoil (mg/kg)        1E-02



 Constituent name       m-Dinitrobenzene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       2,4-Dinitrophenol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       2,3-Dinitrotoluene (and 2,6-, mixture)

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        5E-03

 MinWater (mg/L)        5E-05

 MaxSoil (mg/kg)        1E+02

 MinSoil (mg/kg)        1E-00

 Constituent name       1,4-Dioxane

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        3E-01

 MinWater (mg/L)        3E-03

 MaxSoil (mg/kg)        6E+03

 MinSoil (mg/kg)        6E+01



 Constituent name       Diphenylamine

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       1,2-Diphenylhydrazine

 Class                  B2

 MaxAir (ug/m 3)        4E-01

 MinAir (ug/m 3)        4E-03

 MaxWater (mg/L)        4E-03

 MinWater (mg/L)        4E-05

 MaxSoil (mg/kg)        9E+01

 MinSoil (mg/kg)        9E-01



 Constituent name       Disulfoton

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Endosulfan

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Endothall

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Endrin

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Epichlorohydrin

 Class                  B2

 MaxAir (ug/m 3)        8E+01

 MinAir (ug/m 3)        8E-01

 MaxWater (mg/L)        4E-01

 MinWater (mg/L)        4E-03

 MaxSoil (mg/kg)        7E+03

 MinSoil (mg/kg)        7E+01



 Constituent name       Ethylbenzene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Ethylene dibromide

 Class                  B2

 MaxAir (ug/m 3)        5E-01

 MinAir (ug/m 3)        5E-03

 MaxWater (mg/L)        4E-05

 MinWater (mg/L)        4E-07

 MaxSoil (mg/kg)        8E-01

 MinSoil (mg/kg)        8E-03



 Constituent name       Formaldehyde

 Class                  B1

 MaxAir (ug/m 3)        8E-00

 MinAir (ug/m 3)        8E-02

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Formic acid

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Glycidyaldehyde

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Heptachlor

 Class                  B2

 MaxAir (ug/m 3)        8E-02

 MinAir (ug/m 3)        8E-04

 MaxWater (mg/L)        8E-04

 MinWater (mg/L)        8E-06

 MaxSoil (mg/kg)        2E+01

 MinSoil (mg/kg)        2E-01



 Constituent name       Heptachlor epoxide

 Class                  B2

 MaxAir (ug/m 3)        4E-02

 MinAir (ug/m 3)        4E-04

 MaxWater (mg/L)        4E-04

 MinWater (mg/L)        4E-06

 MaxSoil (mg/kg)        8E-00

 MinSoil (mg/kg)        8E-02



 Constituent name       Hexachlordibenzo-p-dioxin

 Class                  B2

 MaxAir (ug/m 3)        6E-05

 MinAir (ug/m 3)        6E-07

 MaxWater (mg/L)        6E-07

 MinWater (mg/L)        1E-08

 MaxSoil (mg/kg)        1E-02

 MinSoil (mg/kg)        1E-04



 Constituent name       Hexachlorobutadiene

 Class                  C

 MaxAir (ug/m 3)        4E-00

 MinAir (ug/m 3)        4E-02

 MaxWater (mg/L)        4E-02

 MinWater (mg/L)        4E-04

 MaxSoil (mg/kg)        9E+02

 MinSoil (mg/kg)        9E-00



 Constituent name       alpha-Hexachlorocyclohexane

 Class                  B2

 MaxAir (ug/m 3)        6E-02

 MinAir (ug/m 3)        6E-04

 MaxWater (mg/L)        6E-04

 MinWater (mg/L)        6E+06

 MaxSoil (mg/kg)        1E-01

 MinSoil (mg/kg)        1E-01



 Constituent name       beta-Hexachlorocyclohexane

 Class                  C

 MaxAir (ug/m 3)        2E-01

 MinAir (ug/m 3)        2E-03

 MaxWater (mg/L)        2E-03

 MinWater (mg/L)        2E-05

 MaxSoil (mg/kg)        4E+01

 MinSoil (mg/kg)        4E-01



 Constituent name       Hexachlorocyclopentadiene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Hexachloroethane

 Class                  C

 MaxAir (ug/m 3)        3E+01

 MinAir (ug/m 3)        3E-01

 MaxWater (mg/L)        3E-01

 MinWater (mg/L)        3E-03

 MaxSoil (mg/kg)        5E+03

 MinSoil (mg/kg)        5E+01



 Constituent name       Hexachlorophene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)

 Constituent name       Hydrazine

 Class                  B2

 MaxAir (ug/m 3)        2E-02

 MinAir (ug/m 3)        2E-04

 MaxWater (mg/L)        1E-03

 MinWater (mg/L)        1E-05

 MaxSoil (mg/kg)        2E+01

 MinSoil (mg/kg)        2E-01



 Constituent name       Hydrogen cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Hydrogen sulfite

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Isobutyl alcohol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Isophorone

 Class                  C

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        9E-01

 MinWater (mg/L)        9E-03

 MaxSoil (mg/kg)        2E+04

 MinSoil (mg/kg)        2E+02



 Constituent name       Lead

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Lindane (gamma-hexachlorocyclohexane)

 Class                  B2/C

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        3E-03

 MinWater (mg/L)        3E-05

 MaxSoil (mg/kg)        5E+01

 MinSoil (mg/kg)        5E-01



 Constituent name       m-Phenylenediamine

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Maleic anhydride

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Maleic hydrazide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Mercury (inorganic)

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Methacrylonitrile

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Methomyl

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Methyl chlorocarbonate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Methyl ethyl ketone

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Methyl isobutyl ketone

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Methyl parathion

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Methylene chloride

 Class                  B

 MaxAir (ug/m 3)        3E+01

 MinAir (ug/m 3)        3E-01

 MaxWater (mg/L)        5E-01

 MinWater (mg/L)        5E-03

 MaxSoil (mg/kg)        9E+03

 MinSoil (mg/kg)        9E+01



 Constituent name       n-Nitroso-di-n-butylamine

 Class                  B2

 MaxAir (ug/m 3)        6E-02

 MinAir (ug/m 3)        6E-04

 MaxWater (mg/L)        6E-04

 MinWater (mg/L)        6E+06

 MaxSoil (mg/kg)        1E-01

 MinSoil (mg/kg)        1E-01



 Constituent name       n-Nitroso-n-ethylurea

 Class                  B

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       n-Nitroso-n-methylethylamine

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        2E-04

 MinWater (mg/L)        2E-06

 MaxSoil (mg/kg)        3E-00

 MinSoil (mg/kg)        3E-02



 Constituent name       n-Nitrosodi-n-propylamine

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        5E-04

 MinWater (mg/L)        5E-06

 MaxSoil (mg/kg)        1E+01

 MinSoil (mg/kg)        1E-01

 Constituent name       n-Nitrosodiethanolamine

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        1E-03

 MinWater (mg/L)        1E-05

 MaxSoil (mg/kg)        3E+01

 MinSoil (mg/kg)        3E-01



 Constituent name       n-Nitrosodiphenylamine

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        7E-01

 MinWater (mg/L)        7E-03

 MaxSoil (mg/kg)        1E+04

 MinSoil (mg/kg)        1E+02



 Constituent name       n-Nitrosopyrrolidine

 Class                  B2

 MaxAir (ug/m 3)        2E-01

 MinAir (ug/m 3)        2E-03

 MaxWater (mg/L)        2E-03

 MinWater (mg/L)        2E-05

 MaxSoil (mg/kg)        3E+01

 MinSoil (mg/kg)        3E-01



 Constituent name       Nickel

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        7



 Constituent name       Nickel refinery dust

 Class                  A

 MaxAir (ug/m 3)        4E-01

 MinAir (ug/m 3)        4E-03

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Nitric oxide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Nitrobenzene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name        Nitrogen dioxide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Osmium tetroxide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Parathion

 Class                  C

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Pentachlorobenzene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Pentachloronitrobenzene

 Class                  C

 MaxAir (ug/m 3)        1E-00

 MinAir (ug/m 3)        1E-02

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Pentachlorophenol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Phenol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Phenyl mercuric acetate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)

 Constituent name       Phosphine

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Phthalic anhydride

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Polychlorinated biphenyls

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        5E-04

 MinWater (mg/L)        5E-06

 MaxSoil (mg/kg)        9E-00

 MinSoil (mg/kg)        9E-02



 Constituent name       Potassium cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Potassium silver cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Pronamide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Pyridine

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Selenious acid

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Selenourea

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Silver

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Silver cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Sodium cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Strychnine

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Styrene

 Class                  C

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       1,1,1,2-Tetrachlorethane

 Class                  C

 MaxAir (ug/m 3)        1E+01

 MinAir (ug/m 3)        1E-01

 MaxWater (mg/L)        1E-01

 MinWater (mg/L)        3E+03

 MaxSoil (mg/kg)        3E+03

 MinSoil (mg/kg)        3E+01



 Constituent name       1,2,4,5-Tetrachlorobenzene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       1,1,1,2-Tetrachloroethane

 Class                  C

 MaxAir (ug/m 3)        1E+01

 MinAir (ug/m 3)        1E-01

 MaxWater (mg/L)        1E-01

 MinWater (mg/L)        1E-03

 MaxSoil (mg/kg)        3E+03

 MinSoil (mg/kg)        3E+01



 Constituent name       1,1,2,2-Tetrachloroethane

 Class                  C

 MaxAir (ug/m 3)        2E-00

 MinAir (ug/m 3)        2E-02

 MaxWater (mg/L)        2E-02

 MinWater (mg/L)        2E-04

 MaxSoil (mg/kg)        4E+02

 MinSoil (mg/kg)        4E-00



 Constituent name       Tetrachloroethylene

 Class                  B2

 MaxAir (ug/m 3)        1E+02

 MinAir (ug/m 3)        1E-00

 MaxWater (mg/L)        7E-02

 MinWater (mg/L)        7E-04

 MaxSoil (mg/kg)        1E+03

 MinSoil (mg/kg)        1E+01



 Constituent name       2,3,4,6-Tetrachlorophenol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Tetraethyl lead

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Tetraethyldithiopyrophosphate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)

 Constituent name       Thallic oxide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Thallium acetate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Thallium carbonate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Thallium chloride

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Thallium nitrate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Thallium sulfate

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Thiosemicarbazide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Thiram

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Toluene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Toxaphene

 Class                  B2

 MaxAir (ug/m 3)        3E-01

 MinAir (ug/m 3)        3E-03

 MaxWater (mg/L)        3E-03

 MinWater (mg/L)        3E-05

 MaxSoil (mg/kg)        6E+01

 MinSoil (mg/kg)        6E-01



 Constituent name       1,2,4-Trichlorobenzene

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       1,1,1,Trichloroethane

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       1,1,2-Trichloroethane

 Class                  C

 MaxAir (ug/m 3)        6E-00

 MinAir (ug/m 3)        6E-02

 MaxWater (mg/L)        6E-02

 MinWater (mg/L)        6E-04

 MaxSoil (mg/kg)        1E+03

 MinSoil (mg/kg)        1E+01



 Constituent name       Trichloroethylene

 Class                  B2

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)        3E-01

 MinWater (mg/L)        3E-03

 MaxSoil (mg/kg)        6E+03

 MinSoil (mg/kg)        6E+01



 Constituent name       Trichloromonofluoromethane

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       2,4,5-Trichlorophenol

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       2,4,6-Trichlorophenol

 Class                  B2

 MaxAir (ug/m 3)        2E+01

 MinAir (ug/m 3)        2E-01

 MaxWater (mg/L)        2E-01

 MinWater (mg/L)        2E-03

 MaxSoil (mg/kg)        4E+03

 MinSoil (mg/kg)        4E+01



 Constituent name       2,4,5-Trichlorophenoxyacetic acid

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       1,2,3-Trichloropropane

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Vanadium pentoxide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Xylenes

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)



 Constituent name       Zinc cyanide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)

 Constituent name       Zinc phosphide

 Class                  D

 MaxAir (ug/m 3)

 MinAir (ug/m 3)

 MaxWater (mg/L)

 MinWater (mg/L)

 MaxSoil (mg/kg)

 MinSoil (mg/kg)







Appendix  D:  Recommended  Exposusre Assumptions for Use in Deriving Action

Levels



(Sections 264.521 (a)(2); (b); (c)(3); and (d))



    1.  In  deriving  action  levels  for hazardous constituents in ground-

water,  assume  a  water  intake  of  2  liters/day for 70 kg adult/70 year

lifetime exposure period.



    2.  In deriving action levels for hazardous constituents in air, assume

air intake of 20 cubic meters/day for 70 kg adult/70 year lifetime exposure

period.



    3.  In deriving action levels for hazardous constituents in soil, which

are  known  or  suspected  to  be  carcinogens,  assume  soil intake of 0.1

gram/day for 70 kg adult/70 year lifetime exposure period.



    4.  In deriving action levels for hazardous constituents in soil, other

than  those  which  are  known  or suspected to be carcinogens, assume soil

intake  of  0.2  gram/day  for  16  kg  child/5  year  exposure period (age

1-6).*Note Not to be averaged over a 70-year lifetime.



    5.  In  deriving  action  levels  for hazardous constituents in surface

water  designated by the State for use as a drinking water source, assume a

water  intake  of  2  liters/day  for 70 kg adult/70 year lifetime exposure

period, unless intake of aquatic organisms is also of concern.



Appendix E: Examples of Calculations of Action Levels



I. Governing Equations for Calculating Action Levels



    A. Systemic Toxicants

C sub m RfD*W / I*A



where:



C sub m action level in medium (units are medium-dependent);



RfD reference dose (mg/kg/day);



W body weight (kg);



I intake assumption (units are medium-dependent); and



A absorption factor fn 1 (dimensionless).



fn  1 Assumed to be 1 for this appendix, based upon the assumption that the

human  absorption rate will be the same as the rate in the study upon which

the RfD or CPF was developed.



    B. Carcinogenic Constituents



C sub m R*W*LT / CSF*I*A*ED

where:



C sub m action level in medium (units are medium- dependent);



R  assumed  risk  level (dimensionless) (10sup -6 for class A & B; 10sup -5

for class C carcinogens);



W body weight (kg);



LT assumed lifetime (years);



CSF carcinogenic slope factor (mg/kg/day)sup -1;



I intake assumption (units are medium- dependent);



A absorption factor (dimensionless); and



ED exposure duration (years).



II. Example Calculations for Hazardous Constituents in Air



    A. Systemic Toxicants

    Example calculation for 2,4-dinitrophenol:



C  sub  a  0.002 (mg/kg/d)*1000 ( mu g/mg)*70(kg) / 20 (m sup 3/d)*1 7.0 mu

g/m sup 3



where:



C sub a action level in air ( mu g/m sup 3)



RfD 0.002 mg/kg/day



W 70 kg adult



I 20 m sup 3/day



A 1



    B. Carcinogenic Constituents



    Example calculation for 1,1,2,2-tetrachloroethane:



C  sub  a  10sup  -5*1000 ( mu g/mg)*70 (yrs)*70 (kg) / 0.20 (mg/kg/day)sup

-1*20 (m sup 3/day)*1*70 (yrs) .175 mu g/m



where:



C sub a action level in air ( mu g/m sup 3)



R 10sup -5 (1,1,2,2-Tetrachloroethane is a Class C carcinogen)



W 70 kg adult



LT 70 year lifetime



CSF 0.20 (mg/kg/day)sup -1



I 20 m sup 3/day



A 1



ED 70 year exposure duration



III. Sample Calculation for Hazardous Constituents in Water

    A. Systemic Toxicants



    Sample calculation for toluene:



C sub w 0.30 (mg/kg/day)*70 (kg) / 2 (L/day)*1 10.5 mg/L



where:



C sub w action level in water (mg/L)



RfD 0.30 mg/kg/day for toluene



W 70 kg adult



I 2 L/day



A 1



    B. Carcinogenic Constituents



    Sample calculation for 1,1,2,2,-tetrachloroethane:

C  sub  w  10sup -5*70 (kg)*70 (yr) / 0.20 (mg/kg/day)sup -1*2 (L/day)*1*70

(yr) 1.75E-03 mg/L



where:



C sub w action level in water (mg/L)



R 10sup -5 (1,1,2,2-Tetrachloroethane is a Class C carcinogen)



W 70 kg adult



LT 70 year lifetime



CSF 0.20 (mg/kg/day)sup -1



I 2 L/day



A 1



ED 70 year exposure duration



IV. Sample Calculations for Hazardous Constituents in Soils

    A. Systemic Toxicants



    Example calculations for toluene:



C sub 5 0.30 (mg/kg/day)*16 (kg) / 0.2 (g/day)*1*0.001 (kg/g 24,000 mg/kg



where:



C sub 5 action level in soil (mg/kg)



RfD 0.30 mg/kg/day for toluene



W 16 kg (5 year old child)



I 0.2 g/day



A 1



    B. Carcinogenic Constituents



    Sample calculation for 1,1,2,2,-tetrachloroethane:

C   sub   s   10sup  -5*70  (kg)*70  (yrs)  /  0.20  (mg/kg/day)sup  -1*0.1

(g/day)*0.001 (kg/g)*1*70 (yrs) 35.0 mg/kg



where:



C sub s action level in soil (mg/kg)



R 10sup -5 (1,1,2,2-tetrachloroethane is a Class C carcinogen)



W 70 kg adult



LT 70 year lifetime



CSF 0.20 (mg/kg/day)sup -1



I 0.1 g/day



A 1



ED 70 year exposure duration



 Appendix F-List of Constituents Showing Action Level Source Data



 Constituent name                              Acetone

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Acetonitrile

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         6.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Acetophenone

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-01

    Inhalation RFD (mg/kg/d)                   5.0E-05

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Acrylamide

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              4.5E-00

    Inhalation slope factor (mg/kg/d) fn 1     4.5E-00



 Constituent name                              Acrylonitrile

 Class                                         B1

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              5.4E-01

    Inhalation slope factor (mg/kg/d) fn 1     2.4E-01



 Constituent name                              Aldicarb

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.3E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Aldrin

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.7E+01

    Inhalation slope factor (mg/kg/d) fn 1     1.7E+01



 Constituent name                              Allyl alcohol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Aluminum phosphide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         4.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Aniline

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              5.7E-03

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Antimony

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         4.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Arsenic

 Class                                         A

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1     5.0E+01



 Constituent name                              Asbestos (2)

 Class                                         A

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1     2.3E-01



 Constituent name                              Barium cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         7.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Barium, ionic

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-02

    Inhalation RFD (mg/kg/d)                   1.0E-04

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Benzidine

 Class                                         A

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              2.3E+02

    Inhalation slope factor (mg/kg/d) fn 1     2.3E+02



 Constituent name                              Beryllium

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              4.3E-00

    Inhalation slope factor (mg/kg/d) fn 1     8.4E-00

 Constituent name                              Bis(2-

 ethylhexyl)phthlate

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.4E-02

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name

 Bis(chloroethyl)ether

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.1E-00

    Inhalation slope factor (mg/kg/d) fn 1     1.1E-00



 Constituent name

 Bromodichloromethane

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.3E-00

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Bromoform

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Bromomethane

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.4E-03

    Inhalation RFD (mg/kg/d)                   8.0E-03

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Butyl benzyl

 phthalate

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Cadmium

 Class                                         B1

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1     6.1E-00



 Constituent name                              Calcium cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         4.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Carbon disulfide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Carbon

 tetrachloride

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         7.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.3E-01

    Inhalation slope factor (mg/kg/d) fn 1     1.3E-01



 Constituent name                              Chloral

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Chlordane

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         6.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.3E-00

    Inhalation slope factor (mg/kg/d) fn 1     1.3E-00



 Constituent name                              Chlorine cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Chlorobenzene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)                   5.0E-03

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Chloroform

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              6.1E-03

    Inhalation slope factor (mg/kg/d) fn 1     8.1E-02



 Constituent name                              2-Chlorophenol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Chromium (VI)

 Class                                         A

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1     4.1E+01



 Constituent name                              Copper cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              m-Cresol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1

 Constituent name                              o-Cresol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              p-Cresol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Cyanogen

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         4.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Cyanogen bromide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         9.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              DDD

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              2.4E-01

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              DDE

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              3.4E-01

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              DDT

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              3.4E-01

    Inhalation slope factor (mg/kg/d) fn 1     3.4E-01



 Constituent name                              Dibutyl phthalate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Dibutylnitrosamine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              5.4E-00

    Inhalation slope factor (mg/kg/d) fn 1     5.4E-00



 Constituent name                              3,3 minutes -

 Dichlorobenzidine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              4.5E-01

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name

 Dichlorodifluoromethane

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-01

    Inhalation RFD (mg/kg/d)                   5.0E-02

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1

 Constituent name                              1,2-Dichloroethane

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              9.1E-02

    Inhalation slope factor (mg/kg/d) fn 1     9.1E-02



 Constituent name                              1,1-

 Dichloroethylene

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         9.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              6.0E-01

    Inhalation slope factor (mg/kg/d) fn 1     1.2E-00



 Constituent name                              2,4-Dichlorophenol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              2,4-

 Dichlorophenoxyacetic acid

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              1,3-Dichloropropene

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Dieldrin

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.6E+01

    Inhalation slope factor (mg/kg/d) fn 1     1.6E+01



 Constituent name                              Diethyl phthalate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         8.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Diethylnitrosamine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.5E+02

    Inhalation slope factor (mg/kg/d) fn 1     1.5E+02



 Constituent name                              Dimethoate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Dimethylnitrosamine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              5.1E+01

    Inhalation slope factor (mg/kg/d) fn 1     5.1E+01



 Constituent name                              m-Dinitrobenzene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              2,4-Dinitrophenol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1

 Constituent name                              2,3-Dinitrotoluene

 (and 2,6-, mixture)

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              6.8E-01

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              1,4-Dioxane

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.1E-02

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Diphenylamine

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.5E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              1,2-

 Diphenylhydrazine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              8.0E-01

    Inhalation slope factor (mg/kg/d) fn 1     8.0E-01



 Constituent name                              Disulfoton

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         4.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Endosulfan

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Endothall

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Endrin

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Epichlorohydrin

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              9.9E-03

    Inhalation slope factor (mg/kg/d) fn 1     4.2E-03



 Constituent name                              Ethylbenzene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Ethylene dibromide

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              8.5E+01

    Inhalation slope factor (mg/kg/d) fn 1     7.6E-01



 Constituent name                              Formaldehyde

 Class                                         B1

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1     4.5E-02

 Constituent name                              Formic acid

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-00

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Glycidyaldehyde

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         4.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Heptachlor

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              4.5E-00

    Inhalation slope factor (mg/kg/d) fn 1     4.5E-00



 Constituent name                              Heptachlor epoxide

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.3E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              9.1E-00

    Inhalation slope factor (mg/kg/d) fn 1     9.1E-00



 Constituent name                              Hexachlordibenzo-p-

 dioxin

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              6.2E+03

    Inhalation slope factor (mg/kg/d) fn 1     6.2E+03



 Constituent name                              Hexachlorobutadiene

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              7.8E-02

    Inhalation slope factor (mg/kg/d) fn 1     7.8E-02



 Constituent name                              alpha-

 Hexachlorocyclohexane

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              6.3E-00

    Inhalation slope factor (mg/kg/d) fn 1     6.3E-00



 Constituent name                              beta-

 Hexachlorocyclohexane

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.8E-00

    Inhalation slope factor (mg/kg/d) fn 1     1.8E-00



 Constituent name

 Hexachlorocyclopentadiene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         7.0E-03

    Inhalation RFD (mg/kg/d)                   2.0E-05

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Hexachloroethane

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.4E-02

    Inhalation slope factor (mg/kg/d) fn 1     1.4E-02



 Constituent name                              Hexachlorophene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Hydrazine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              3.0E-00

    Inhalation slope factor (mg/kg/d) fn 1     1.7E+01



 Constituent name                              Hydrogen cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Hydrogen sulfite

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Isobutyl alcohol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Isophorone

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              4.1E-03

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Lead

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Lindane (gamma-

 hexachlorocyclohexane)

 Class                                         B2/C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.3E-00

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              m-Phenylenediamine

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         6.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1

 Constituent name                              Maleic anhydride

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Maleic hydrazide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Mercury (inorganic)

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Methacrylonitrile

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-04

    Inhalation RFD (mg/kg/d)                   2.0E-04

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Methomyl

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.5E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Methyl

 chlorocarbonate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Methyl ethyl ketone

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-02

    Inhalation RFD (mg/kg/d)                   9.0E-02

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Methyl isobutyl

 ketone

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-02

    Inhalation RFD (mg/kg/d)                   2.0E-02

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Methyl parathion

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.5E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Methylene chloride

 Class                                         B

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         6.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              7.5E-03

    Inhalation slope factor (mg/kg/d) fn 1     1.4E-02



 Constituent name                              n-Nitroso-di-n-

 butylamine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              5.4E-00

    Inhalation slope factor (mg/kg/d) fn 1     5.4E-00



 Constituent name                              n-Nitroso-n-

 ethylurea

 Class                                         B

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              n-Nitroso-n-

 methylethylamine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              2.2E+01

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              n-Nitrosodi-n-

 propylamine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              7.0E-00

    Inhalation slope factor (mg/kg/d) fn 1

 Constituent name                              n-

 Nitrosodiethanolamine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              2.8E-00

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              n-

 Nitrosodienylamine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              4.9E-03

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              n-

 Nitrosopyrrolidine

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              2.1E-00

    Inhalation slope factor (mg/kg/d) fn 1     2.1E-00



 Constituent name                              Nickel

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Nickel refinery

 dust

 Class                                         A

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1     8.4E-01



 Constituent name                              Nitric oxide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Nitrobenzene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-04

    Inhalation RFD (mg/kg/d)                   60E-04

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Nitrogen dioxide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-00

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Osmium tetroxide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Parathion

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         6.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Pentachlorobenzene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         8.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name

 Pentachloronitrobenzene

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1     2.5E-01



 Constituent name                              Pentachlorophenol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Phenol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         6.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Phenyl mercuric

 acetate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         8.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Phosphine

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Phthalic anhydride

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-00

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Polychlorinated

 biphenyls

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              7.7E-00

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Potassium cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Potassium silver

 cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Pronamide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         7.5E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Pyridine

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Selenious acid

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Selenourea

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Silver

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Silver cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1

 Constituent name                              Sodium cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         4.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Strychnine

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Styrene

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              1,1,1,2-

 Tetrachlorethane

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              2.6E-02

    Inhalation slope factor (mg/kg/d) fn 1     2.6E-02



 Constituent name                              1,2,4,5-

 Tetrachlorobenzene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              1,1,1,2-

 Tetrachloroethane

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              2.6E-02

    Inhalation slope factor (mg/kg/d) fn 1     2.6E-02



 Constituent name                              1,1,2,2-

 Tetrachloroethane

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              2.0E-01

    Inhalation slope factor (mg/kg/d) fn 1     2.0E-01



 Constituent name                              Tetrachloroethylene

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              5.1E-02

    Inhalation slope factor (mg/kg/d) fn 1     3.3E-03



 Constituent name                              2,3,4,6-

 Tetrachlorophenol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Tetraethyl lead

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-07

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name

 Tetraethyldithiopyrophosphate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Thallic oxide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         7.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Thallium acetate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         9.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Thallium carbonate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         8.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1

 Constituent name                              Thallium chloride

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         8.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Thallium nitrate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         9.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Thallium sulfate

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         8.0E-05

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Thiosemicarbazide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         6.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Thiram

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Toluene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-01

    Inhalation RFD (mg/kg/d)                   2.0E-00

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Toxaphene

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.1E-00

    Inhalation slope factor (mg/kg/d) fn 1     1.1E-00



 Constituent name                              1,2,4-

 Trichlorobenzene

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-02

    Inhalation RFD (mg/kg/d)                   3.0E-03

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              1,1,1-

 Trichloroethane

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         9.0E-02

    Inhalation RFD (mg/kg/d)                   3.0E-01

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              1,1,2-

 Trichloroethane

 Class                                         C

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         4.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              5.7E-02

    Inhalation slope factor (mg/kg/d) fn 1     5.7E-02



 Constituent name                              Trichloroethylene

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              1.1E-02

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name

 Trichloromonofluoromethane

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-01

    Inhalation RFD (mg/kg/d)                   2.0E-01

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              2,4,5-

 Trichlorophenol

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-01

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              2,4,6-

 Trichlorophenol

 Class                                         B2

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1              2.0E-02

    Inhalation slope factor (mg/kg/d) fn 1     2.0E-02

 Constituent name                              2,4,5-

 Trichlorophenoxyacetic acid

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         1.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              1,2,3-

 Trichloropropane

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         6.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Vanadium pentoxide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         9.0E-03

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Xylenes

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         2.0E-00

    Inhalation RFD (mg/kg/d)                   3.0E-01

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Zinc cyanide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         5.0E-02

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1



 Constituent name                              Zinc phosphide

 Class                                         D

 Noncarcinogenic effects

    Oral RFD (mg/kg/d)                         3.0E-04

    Inhalation RFD (mg/kg/d)

 Carcinogenic effects

    Oral slope factor (mg/kg/d)-1

    Inhalation slope factor (mg/kg/d) fn 1







    For  the  reasons  set out in the preamble, 40 CFR parts 264, 265, 270.

and 271 are proposed to be amended as follows:



PART  264- STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE

TREATMENT,

STORAGE, AND DISPOSAL FACILITIES



    1. The authority citation for part 264 continues to read as follows:

    Authority: 42 U.S.C. 6905, 6912(a). 6924, and 6925.



    2.  Section  264.1  is  amended  by  revising  paragraphs  (d)  and (g)

introductory  text  to  read  as  follows:  Sec.  264.1  Purpose, scope and

applicability.



    (d)  The  requirements  of  this  part  apply  to a person disposing of

hazardous  waste  by  means  of  underground  injection subject to a permit

issued  under  an  Underground  Injection control (UIC) program approved or

promulgated  under  the Safe Drinking Water Act only to the extent they are

required by Sec. 144.14 of this chapter and to the extent they are included

in  a  RCRA  permit by rule granted to such a person under part 270 of this

chapter.



    (g)  Except as required under subpart S of this part governing releases

from  solid  waste  management  units, the requirements of this part do not

apply to: Sec. 264.101  Removed



    3.  In  40  CFR  part  264,  subpart  F,  it is proposed to remove Sec.

264.101.



    4.  In 40 CFR part 264, subpart G, it is proposed to amend Sec. 264.113

by  redesignating  paragraphs  (a)(1)(ii)  as (a)(1)(iii) and (b)(1)(ii) as

(b)(1)(iii), and by adding new paragraphs (a)(1)(ii) and (b)(1)(ii) to read

as follows: Sec. 264.113 Closure time allowed for closure.



    (a)



    (1)



    (ii)  Corrective  action  required  at  the  unit or the facility under

subpart S will delay the completion of partial or final closure; or



    (b)



    (1)



    (ii)  Corrective  action  required  at  the  unit or the facility under

subpart S will delay the completion of partial or final closure; or



    5. 40 CFR part 264 is amended by adding subpart S to read as follows:



Subpart S-Corrective Action for Solid Waste Management Units

264.500 Purpose and applicability.



264.501 Definitions.



264.502-264.509 Reserved .



264.510 Requirement to perform remedial investigations. {pg 30874}



264.511 Scope of remedial investigations.



264.512 Plans for remedial investigations.



264.513 Reports of remedial investigations.



264.514 Determination of no further action.



264.515-264.519 Reserved



264.520 Requirement to perform corrective measure study.



264.521 Action levels.

264.522 Scope of corrective measure studies.



264.523 Plans for corrective measure studies.



264.524 Reports of corrective measure studies.



264.525 Selection of remedy



264.526 Permit modification for remedy.



264.527 Remedy design.



264.528 Progress reports.



264.529 Review of remedy implementation.



264.530 Completion of remedies.



264.531 Determination of technical impracticability.



264.532-264.539 Reserved

264.540 Interim measuras.



264.541-264.549 Reserved



264.550 Management of wastes.



264.551 Management of hazardous wastes.



264.552 Management of non-hazardous solid wastes.



264.553-264.559 Reserved



264.560 Required notices.



SUBPART  S-Corrective  Action for Solid Waste Management Units Sec. 264.500

Purpose and applicability.



    (a)   The   provisions  of  this  subpart  establish  requirements  for

investigation  and  corrective  action  for  releases  of  hazardous waste,

including hazardous constituents, from solid waste management units.



    (b) The owner or operator of a facility seeking a permit under subtitle

C  of  RCRA  must  institute  investigations  and/or  corrective action, as

necessary  to protect human health and the environment, for all releases of

hazardous  waste,  including  hazardous  constituents, from any solid waste

management  unit at the facility, regardless of the time at which waste was

placed in such unit.



    (c)  Requirements  for  investigations and/or corrective action will be

specified  in  the  permit. The permit will contain schedules of compliance

for  such  investigations  and/or  corrective  action (where such cannot be

completed  prior  to  issuance  of  the permit) and assurances of financial

responsibility for completing such corrective action.



    (d)  The owner or operator must implement corrective actions beyond the

facility property boundary, where necessary to protect human health and the

environment,  unless the owner or operator demonstrates to the satisfaction

of  the Regional Administrator that, despite the owner's or operator's best

efforts,  the  owner  or  operator  was  unable  to  obtain  the  necessary

permission to undertake such actions. The owner or operator is not relieved

of  responsibility  to  clean  up  a  release  that has migrated beyond the

facility  boundary  where  off-  site access is denied. On-site measures to

address   such  releases  will  be  determined  on  a  case-by-case  basis.

Assurances  of  financial  responsibility  for  completing  such corrective

action must be provided.



    (e)   For   protection   of   ground   water  from  landfills,  surface

impoundments, land treatment units, and waste piles that received listed or

identified  hazardous  waste  after  July  26, 1982, the provisions of this

subpart apply only as specifically provided herein.



    (f) The provisions of this subpart do not apply to:



    (1)  Permits  for  land  treatment  demonstrations  using field test or

laboratory analyses (see Sec. 270.63).



    (2) Emergency permits (see Sec. 270.61).



    (3)  Permits  by  rule  for  ocean disposal barges or vessels (see Sec.

270.60(a)).



    (4) Research, development, and demonstration permits (see Sec. 270.65).

Sec. 264.501 Definitions.



    For the purpose of complying with the requirements of this subpart, the

following definitions apply:

    Corrective  Action  Management  Unit  means  a contiguous area within a

facility  as  designated  by  the Regional Administrator for the purpose of

implementing  corrective  action  requirements  of  this  subpart, which is

contaminated  by  hazardous  wastes (including hazardous constituents), and

which may contain discrete, engineered land-based sub-units.



    Facility  means  all contiguous property under the control of the owner

or operator seeking a permit under subtitle C of RCRA.



    Hazardous Constituent means any constituent identified in appendix VIII

of  40 CFR part 261, or any constituent identified in appendix IX of 40 CFR

part 264.



    Hazardous  Waste  means  a solid waste, or combination of solid wastes,

which  because  of  its  quantity,  concentration, or physical chemical, or

infectious  characteristics  may  cause, or significantly contribute to, an

increase   in   mortality  or  an  increase  in  serious  irreversible,  or

incapacitating  reversible,  illness;  or  pose  a  substantial  present or

potential  hazard  to  human  health  or  the  environment  when improperly

treated,  stored,  transported,  or  disposed of, or otherwise managed. The

term hazardous waste includes hazardous constituent as defined above.

    Release  means  any  spilling,  leaking,  pouring,  emitting, emptying,

discharging,  injecting, pumping, escaping, leaching, dumping, or disposing

of hazardous wastes (including hazardous constituents) into the environment

(including  the abandonment or discarding of barrels, containers, and other

closed receptacles containing hazardous wastes or hazardous constituents).



    Solid  Waste  Management Unit means any discernible unit at which solid

wastes  have  been placed at any time, irrespective of whether the unit was

intended for the management of solid or hazardous waste. Such units include

any  area  at  a  facility  at  which  solid wastes have been routinely and

systematically   released.  Secs.  264.502-264.509  Reserved  Sec.  264.510

Requirement to perform remedial investigations.



    If   the   Regional   Administrator  determines  that  hazardous  waste

(including  hazardous constituents) have been, are likely to have been, or,

based  on  site-specific  circumstances, are likely to be released into the

environment  from  a  solid  waste  management  unit  at  the facility, the

Regional  Administrator  may  specify  in the permit schedule of compliance

that  the  permittee  investigate  and  characterize solid waste management

units  and releases from solid waste management units at the facility. Sec.

264.511 Scope of remedial investigations.

    (a)  Investigations  required under Sec. 264.510 shall characterize the

nature, extent, direction, rate, movement and concentration of releases, as

required  by  the  Regional Administrator. In addition, such investigations

may include, but are not limited to, the following:



    (1)  Characterizations  of  the  environmental setting at the facility,

including:



    (i) Hydrogeological conditions;



    (ii) Climatological conditions;



    (iii) Soil characteristics;



    (iv) Surface water and sediment quality and other characteristics; or



    (v) Air quality and meteorological conditions.



    (2)  Characterization  of  solid  waste  management  units  from  which

releases   have  been  or  may  be  occurring,  including  unit  and  waste

characteristics.

    (3)  Descriptions  of  humans  and environmental systems which are, may

have  been,  or,  based  on  site-specific circumstances, may be exposed to

release(s).



    (4)   Information  that  will  assist  the  Regional  Administrator  in

assessing  risks  to  human  health  and the environment from releases from

solid waste management units.



    (5)   Extrapolations  of  future  movement,  degradation  and  fate  of

contaminants.



    (6)   Laboratory,  bench-scale  or  pilot-scale  tests  or  studies  to

determine  the  feasibility  or  effectiveness of treatment technologies or

other  technologies that may be appropriate in implementing remedies at the

facility.



    (7)  Statistical analyses to aid in the interpretation of data required

under  Sec. 264.510, in accordance with statistical methods approved by the

Regional Administrator.



    (b)  Samples  of  ground  water, surface water, soils, or air which are

collected as part of remedial investigations {pg 30875} required under Sec.

264.510  shall be analyzed for those constituents and parameters determined

to  be necessary by the Regional Administrator to accurately and adequately

characterize   the   presence  of  hazardous  wastes  (including  hazardous

constituents)   in   the   samples.   Sec.   264.512   Plans  for  remedial

investigations.



    (a) The Regional Administrator may require the permittee to develop and

submit  a plan(s) for conducting any remedial investigations required under

Sec.  264.510  of  this  subpart. Such plans shall be subject to review and

approval  or  modification  by  the  Regional  Administrator,  and shall be

developed  and  submitted according to a schedule specified in the schedule

of  compliance.  Such  plans  may  include,  but  are  not  limited to, the

following:



    (1)    Overall   approach,   including   objectives,   schedules,   and

qualifications of personnel conducting investigations.



    (2) Technical and analytical approach and methods for investigations.



    (3) Quality assurance procedures, including:



    (i) Data collection strategy;

    (ii) Sampling, chain of custody procedures; and



    (iii) Methods of sample analysis.



    (4)  Data  management  procedures,  including  formats  for documenting

analytical  results  and  tracking  sample  custody,  and  other results of

investigations.



    (b)  Upon  approval  or  modification  of  the  plan  by  the  Regional

Administrator,  the plan shall be incorporated expressly or by reference as

a  part  of  the permit schedule of compliance. The permittee shall conduct

the  studies  and  investigations in accordance with the plan and any other

requirements  specified  in the permit schedule of compliance. Sec. 264.513

Reports of remedial investigations.



    (a)  The  Regional  Administrator  may  require  periodic reports to be

submitted  by  the  permittee during remedial investigations required under

Sec.  264.510,  and  may,  based on information from the investigations, or

other   information,   require   new   or   modified  investigations.  Such

modifications  will,  if  necessary,  be  specified by modifying the permit

schedule of compliance.

    (b) Upon conclusion of the remedial investigations, the permittee shall

submit to the Regional Administrator for approval:



    (1)  A  final report describing the procedures, methods, and results of

the remedial investigations, in such format and containing such information

as specified by the Regional Administrator; and



    (2) A summary of the report.



    (c)  If,  upon  receipt  of  the final report and summary, the Regional

Administrator  determines  that  the  final report and summary do not fully

satisfy the requirements for the report and summary specified in the permit

schedule  of  compliance,  or  otherwise do not provide a full and accurate

summary  and  description  of  the  remedial  investigations,  the Regional

Administrator may require the permittee to submit a revised report.



    (d)  Upon  approval  of the summary, the permittee shall mail it to all

individuals   on   the   facility   mailing   list   (required  under  Sec.

124.10(c)(1)(viii)).



    (e)  All  raw data, such as laboratory reports, drilling logs and other

supporting  information  generated  from investigations required under Sec.

264.510  shall be maintained at the facility (or other location approved by

the  Regional  Administrator)  during the term of the permit, including any

reissued permit. Sec. 264.514 Determination of no further action.



    (a)(1)  Based  on  the  results  of  investigations required under Sec.

264.510   or  other  relevant  information  the  permittee  may  submit  an

application  to  the  Regional  Administrator  for a permit modification to

terminate  the  schedule  of compliance for corrective action, according to

the procedures for Class III permit modifications under Sec. 270.42.



    (2)  The  permit  modification  application  must  contain  information

demonstrating  that  there  are  no  releases of hazardous waste (including

hazardous  constituents)  from solid waste management units at the facility

that may pose a threat to human health or the environment.



    (b)  If  the  Regional  Administrator, upon review of the request for a

permit  modification,  reports  submitted  under  Sec.  264.513,  or  other

information,  determines  that  there is no such threat to human health and

the  environment  from  releases  from  solid waste management units at the

facility.  The  Regional  Administrator shall grant the permit modification

according to the procedures of Sec. 270.42.

    (c)  Any determination made pursuant to Sec. 264.514(b) will not affect

the authority or responsibility of the Regional Administrator to:



    (1)  Modify  the  permit  at  a  later date to require the permittee to

perform  such investigations and studies as may be necessary to comply with

the requirements of this Subpart, if new information or subsequent analysis

indicates  that  there  are, or are likely to be, releases from solid waste

management  units at the facility that may pose a threat to human health or

the environment; or



    (2)  Require  continued  or  periodic monitoring under the terms of the

permit  if  the  Regional Administrator determines, based on site- specific

circumstances,  that  releases  are  likely to occur. Secs. 264.515-264.519

Reserved Sec. 264.520 Requirement to perform corrective measure study.



    (a)   If  at  any  time  the  Regional  Administrator  determines  that

concentrations  of  hazardous  constituents  in ground water in an aquifer,

surface  water, soils, or air exceed an action 1eve1 (as defined under Sec.

264.521),  and  there is reason to believe that such hazardous constituents

have  been released from a solid waste management unit at the facility, the

Regional  Administrator  shall  require  as  part of the permit schedule of

compliance that the permittee perform a corrective measure study, according

to the requirements of Secs. 264.522- 264.524, except as otherwise provided

under Sec. 264.520(c).



    (b)  If  the  Regional  Administrator  determines that a constituent(s)

present  in  a  concentration  below an action level (as defined under Sec.

264.521)  may  pose  a  threat  to  human  health or the environment, given

site-specific  exposure conditions, and there is reason to believe that the

constituent(s)  has been released from a solid waste management unit at the

facility, the Regional Administrator may require a corrective measure study

according to the requirements of Secs. 264.522-264.524.



    (c)  If  an  action  level  has  been  exceeded (as provided under Sec.

264.520(a),  but  the Regional Administrator determines that the release(s)

may nevertheless not pose a threat to human health and the environment, the

Regional Administrator may allow the permittee to apply for a determination

of no further action, according to Sec. 264.514.



    (d) The Regional Administrator shall notify the permittee in writing of

the  requirement  to  conduct a corrective measure study. This notice shall

identify  the  hazardous  constituent(s) which exceed action levels defined

under  Sec.  264.521,  as  well  as any hazardous constituent(s) identified

pursuant to Sec. 264.520(b).

    (e)  For  purposes  of Secs. 264.520, 264.521, 264.525 (d) and (e), the

term  ''constituent''  refers  to  hazardous  {pg  30876}  constituents, as

defined  in  Sec. 264.501, as well as other hazardous wastes (as defined in

Sec.  264.501)  that  are single chemical constituents. Sec. 264.521 Action

levels.



    Action levels are defined as follows:



    (a)  Action levels for constituents in ground water in an aquifer which

the  Regional  Administrator  has  reason to believe may have been released

from  a  solid waste management unit at the facility shall be concentration

levels specified as:



    (1)  Maximum  contaminant levels (MCLs) promulgated under Sec. 141.2 of

the Safe Drinking Water Act (40 CFR part 141 subpart B); or



    (2)  For  constituents  for  which  MCLs  have  not been promulgated, a

concentration  which  satisfies  the  following criteria, assuming exposure

through consumption of the water contaminated with the constituent:



    (i)  Is  derived  in  a  manner  consistent  with Agency guidelines for

assessing the health risks of environmental pollutants (51 FR 33992, 34006,

34014, 34028); and



    (ii)  Is  based on scientifically valid studies conducted in accordance

with  the  Toxic  Substances  Control  Act  (TSCA) Good Laboratory Practice

Standards (40 CFR part 792), or equivalent; and



    (iii)  For  carcinogens,  represents a concentration associated with an

excess  upper  bound  lifetime  cancer  risk  of  1x10  sup  6 sup 6 due to

continuous  constant lifetime exposure, and considers the overall weight of

evidence for carcinogenicity; and



    (iv)  For  systemic  toxicants, represents a concentration to which the

human  population  (including  sensitive  subgroups)  could be exposed on a

daily  basis  that  is likely to be without appreciable risk of deleterious

effects during a lifetime.



    (b)   Action   levels  for  constituents  in  air  which  the  Regional

Administrator  has  reason  to  believe may have been released from a solid

waste  management  unit  at the facility shall be defined as concentrations

which  meet  the criteria specified in Sec. 264.521(a)(2)(i)-(iv), assuming

exposure  through  inhalation of the air contaminated with the constituent,

as  measured  or  estimated  at  the facility boundary, or another location

closer   to  the  unit  if  necessary  to  protect  human  health  and  the

environment.



    (c)  Action levels for constituents in surface water which the Regional

Administrator  has  reason  to  believe may have been released from a solid

waste management unit at the facility shall be specified as:



    (1)  Water  Quality Standards established pursuant to section 303(c) of

the Clean Water Act (40 CFR part 131) by the State in which the facility is

located, where such standards are expressed as numeric values; or



    (2) Numeric interpretations of State narrative water quality standards,

if  appropriate,  where water quality standards expressed as numeric values

have not been established by the State; or



    (3) MCLs promulgated under the Safe Drinking Water Act for constituents

in  surface waters designated by the State for drinking water supply, where

numeric  values or numeric interpretations, described in paragraphs (1) and

(2), are not available; or



    (4)  For  constituents  in  surface  waters designated by the State for

drinking water supply for which numeric values, numeric interpretations, or

MCLs   (as  described  in  paragraphs  1-3  above)  are  not  available,  a

concentration    which    meets    the    criteria    specified   in   Sec.

264.521(a)(2)(i)-(iv),  assuming  exposure through consumption of the water

contaminated with the constituent; or



    (5)  For  constituents  in  surface waters designated for a use or uses

other  than  drinking  water supply and for which numeric values or numeric

interpretations  (as  described  in  paragraphs (1) and (2) above) have not

been established, a concentration established by the Regional Administrator

which   meets   the   criteria  specified  in  Sec.  264.521(a)(2)(i)-(iv),

considering the use or uses of the receiving waters.



    (d)   Action  levels  for  constituents  in  soils  that  the  Regional

Administrator  has  reason  to  believe may have been released from a solid

waste  management  unit  at the facility shall be defined as concentrations

which  meet  the criteria specified in Sec. 264.521(a)(2)(i)-(iv), assuming

exposure through consumption of the soil contaminated with the constituent.



    (e)  If,  for  a constituent(s) detected in ground water in an aquifer,

air,  surface water or soils, a concentration level that meets the criteria

of  Sec.  264.521(a)-(d)  is  not available, the Regional Administrator may

establish an action level for the constituent as:

    (1) A level that is an indicator for protection of human health and the

environment,  using the exposure assumptions for the medium specified under

Sec. 264.521(a)-(d); or



    (2)  The background concentration of the constituent.Sec. 264.522 Scope

of corrective measure studies.



    (a)  As  determined  by  the Regional Administrator, corrective measure

studies  required  under  Sec. 264.520 may include, but are not limited to,

the following:



    (1) Evaluation of performance, reliability, ease of implementation, and

potential  impacts  of  the  remedy,  including safety impacts, cross media

impacts, and control of exposure to any residual contamination.



    (2)  Assessment of the effectiveness of potential remedies in achieving

adequate  control  of sources and cleanup of the hazardous waste (including

hazardous constituents) released from solid waste management units.



    (3) Assessment of the time required to begin and complete the remedy.



    (4) Estimation of the costs of remedy implementation.

    (5)  Assessment  of  institutional requirements, such as State or local

permit  requirements,  or other environmental or public health requirements

which may substantially affect implementation of the remedy(s).



    (b) The Regional Administrator may require the permittee to evaluate as

part  of  the  corrective  measure  study  one  or  more specific potential

remedies.  These  remedies may include a specific technology or combination

of technologies that, in the Regional Administrator's judgment, achieves or

may  achieve  the standards for remedies specified in Sec. 264.525(a) given

appropriate consideration of the factors specified in Sec. 264.525(b). Sec.

264.523 Plans for corrective measure studies.



    (a) The Regional Administrator may require the permittee to develop and

submit  a  plan(s) for conducting a corrective measure study required under

Sec.  264.520.  The  plan  shall  be  subject  to  review  and  approval or

modification  by  the  Regional  Administrator,  and shall be developed and

submitted  according  to  a  schedule  specified  in the permit schedule of

compliance. Such plans may include, but are not limited to, the following:



    (1) Description of the general approach to investigating and evaluating

potential remedies;

    (2) Definition of the overall objectives of the study;



    (3) Description of the specific remedy(s) which will be studied;



    (4)  Plans  for  evaluating  remedies  to  ensure  compliance  with the

standards for remedies specified in Sec. 264.525(a);



    (5) Schedules for conducting the study; and {pg 30877}



    (6) Proposed format for information presentation.



    (b)  Upon approval or modification of the corrective measure study plan

by  the Regional Administrator, the plan shall be incorporated expressly or

by  reference  as  part of the permit schedule of compliance. The permittee

shall  conduct  the  studies and investigations in accordance with the plan

and  any  other  requirements  as  specified  in  the  permit  schedule  of

compliance. Sec. 264.524 Reports of corrective measure studies.



    (a)  The Regional Administrator may require periodic reports during the

conduct of the corrective measure study, and may, based on information from

these  reports  or  other  information, require the permittee to modify the

corrective  measure  study.  Such  modifications  will,  if  necessary,  be

specified by modifying the permit schedule of compliance.



    (b)  Upon  completion  of  the  corrective measure study, the permittee

shall  submit  a  report  summarizing the results of the study. This report

must  include  a  detailed description of the remedies assessed pursuant to

Sec. 264.522 or Sec. 264.524(a). The report shall describe how any proposed

remedy(s) meets the standards for remedies as specified in Sec. 264.525(a).



    (c)  Upon  review  of the corrective measure study report, the Regional

Administrator  may  require  the  permittee to evaluate further, and report

upon,  one  or  more additional remedies, or develop particular elements of

one   or  more  proposed  remedies.  Such  further  requirements  will,  if

necessary,  be  specified  by  modifying the permit schedule of compliance.

Sec. 264.525 Selection of remedy.



    Based  on  the results of the corrective measure study, and any further

evaluations  conducted  under  Sec.  264.524(c), the Regional Administrator

shall,  except  as  otherwise provided under paragraph (f) of this section,

select a remedy that, at a minimum, meets the standards listed in paragraph

(a) of this section.



    (a) Standards for remedies. Remedies must:

    (1) Be protective of human health and the environment;



    (2)  Attain media cleanup standards as specified pursuant to paragraphs

(d) and (e) of this section;



    (3)  Control the source(s) of releases so as to reduce or eliminate, to

the  extent  practicable,  further  releases of hazardous wastes (including

hazardous  constituents)  that  may  pose  a threat to human health and the

environment; and



    (4)  Comply  with  standards  for  management of wastes as specified in

Secs. 264.550-264.559 of this subpart.



    (b)  Remedy  selection  factors.  In selecting a remedy which meets the

standards of Sec. 264.525(a), the Regional Administrator shall consider the

following evaluation factors as appropriate:



    (1)  Long-term  reliability  and effectiveness. Any potential remedy(s)

may be assessed for the long-term reliability and effectiveness it affords,

along  with  the degree of certainty that the remedy will prove successful.

Factors that shall be considered in this evaluation include:

    (i)  Magnitude of residual risks in terms of amounts and concentrations

of  waste  remaining  following implementation of a remedy, considering the

persistence,  toxicity,  mobility  and  propensity to bioaccumulate of such

hazardous wastes (including hazardous constituents);



    (ii)  The  type  and degree of long-term management required, including

monitoring and operation and maintenance;



    (iii)  Potential  for exposure of humans and environmental receptors to

remaining wastes;



    (iv)   Long-term  reliability  of  the  engineering  and  institutional

controls,   including   uncertainties  associated  with  land  disposal  of

untreated wastes and residuals; and



    (v) Potential need for replacement of the remedy.



    (2)  Reduction  of  toxicity, mobility or volume. A potential remedy(s)

may be assessed as to the degree to which it employs treatment that reduces

toxicity,  mobility  or  volume  of  hazardous  wastes (including hazardous

constituents).  Factors  that  shall  be  considered  in  such  assessments

include:

    (i)  The  treatment  processes  the  remedy(s) employs and materials it

would treat;



    (ii)  The amount of hazardous wastes (including hazardous constituents)

that would be destroyed or treated;



    (iii) The degree to which the treatment is irreversible;



    (iv)  The  residuals  that will remain following treatment, considering

the persistence, toxicity, mobility and propensity to bioaccumulate of such

hazardous wastes (including hazardous constituents).



    (3)  The  short-term  effectiveness  of  a  potential  remedy(s) may be

assessed considering the following:



    (i) Magnitude of reduction of existing risks;



    (ii) Short-term risks that might be posed to the community, workers, or

the environment during implementation of such a remedy, including potential

threats  to  human  health  and the environment associated with excavation,

transportation, and redisposal or containment;

    (iii) Time until full protection is achieved.



    (4)   Implementability.  The  ease  or  difficulty  of  implementing  a

potential  remedy(s)  may be assessed by considering the following types of

factors:



    (i) Degree of difficulty associated with constructing the technology;



    (ii) Expected operational reliability of the technologies;



    (iii)  Need  to  coordinate  with  and  obtain  necessary approvals and

permits from other agencies;



    (iv) Availability of necessary equipment and specialists;



    (v)  Available  capacity  and location of needed treatment, storage and

disposal services.



    (5)  Cost.  The  types  of  costs  that  may  be  assessed  include the

following:



    (i) Capital costs;

    (ii) Operation and maintenance costs;



    (iii) Net present value of capital and operation and maintenance costs;



    (iv) Potential future remedial action costs.



    (c)  Schedule  for  remedy. The Regional Administrator shall specify as

part  of  the  selected  remedy a schedule(s) for initiating and completing

remedial activities. The Regional Administrator will consider the following

factors in determining the schedule of remedial activities:



    (1) Extent and nature of contamination.



    (2)  Practical  capabilities  of  remedial  technologies  in  achieving

compliance  with  media  cleanup  standards,  and  other  objectives of the

remedy.



    (3)  Availability  of treatment or disposal capacity for wastes managed

during implementation of the remedy.



    (4)  Desirability  of  utilizing  technologies  which are not currently

available,   but  which  may  offer  significant  advantages  over  already

available  technologies  in terms of effectiveness, reliability, safety, or

ability to achieve remedial objectives.



    (5)  Potential  risks to human health and the environment from exposure

to contamination prior to completion of the remedy.



    (6) Other relevant factors.



    (d)  Media  Cleanup  Standards.  Except  as  otherwise provided by Sec.

264.525(d)(2),  the  Regional  Administrator  shall specify in the selected

remedy  requirements  for remediation of contaminated media as follows: {pg

30878}



    (1)  Regional  Administrator  shall  specify  concentration  levels  of

hazardous  constituents  in  ground water, surface water, air or soils that

the  remedy  must  achieve,  as  necessary  to protect human health and the

environment.  Such  media  cleanup  standards  will  be  established by the

Regional Administrator as follows:



    (i)  The  cleanup  standard(s)  shall  be  concentration  levels in the

affected media which protect human health and the environment.

    (ii)  Unless a lower concentration level is deemed necessary to protect

environmental receptors, cleanup standards shall be established as follows:



    (A)  For  known  or  suspected  carcinogens, cleanup standards shall be

established  at  concentration  levels which represent an excess upperbound

lifetime risk to an individual of between 1X10sup - sup 4 and 1X10sup - sup

6  . The Regional Administrator shall use the 1X10sup -6. risk level as the

point of departure in establishing such concentration levels.



    (B)   For   systemic   toxicants,  cleanup  standards  shall  represent

concentration  levels  to  which  the human population (including sensitive

subgroups)  could  be  exposed on a daily basis without appreciable risk of

deleterious effect during a lifetime.



    (iii)   In   establishing   media  cleanup  standards  which  meet  the

requirements  of  Sec.  264.525(d)(1)  (i)  and  (ii),  above, the Regional

Administrator may consider the following:



    (A) Multiple contaminants in the medium;



    (B) Exposure threats to sensitive environmental receptors;

    (C)  Other site-specific exposure or potential exposure to contaminated

media;



    (D)  The  reliability, effectiveness, practicability, or other relevant

features of the remedy.



    (iv)  For ground water and surface water that is a current or potential

source of drinking water, the Regional Administrator shall consider maximum

contaminant  1evels  promulgated  under  section 141.2 of the Safe Drinking

Water  Act  (40  CFR  part  141  subpart  B)  in establishing media cleanup

standards.



    (v)  If  the  permittee  can  demonstrate  to  the  satisfaction of the

Regional  Administrator that a specific concentration of a constituent in a

medium at the facility is naturally occurring or from a source other than a

solid  waste management unit at the facility, the cleanup level established

under  this  Subpart  for  the constituent in the medium shall not be below

that  specific concentration, unless the Regional Administrator establishes

that:



    (A)  Remediation  to  levels  below  that  specified  concentration  is

necessary to protect human health and the environment; and

    (B)  Such  remediation  is in connection with an areawide cleanup under

RCRA or other authorities.



    (2)  The  Regional  Administrator  may  determine that remediation of a

release  of  a  constituent  from  a solid waste management unit to a media

cleanup   standard  established  pursuant  to  Sec.  264.525(d)(1)  is  not

necessary  if  the  permittee  demonstrates to the Regional Administrator's

satisfaction that:



    (i)  The  affected  medium  is also contaminated by substances that are

naturally  occurring  or  have  originated from a source other than a solid

waste  managment  unit at the facility, and those substances are present in

concentrations  such  that  remediation of the release from the solid waste

management  unit  would provide no significant reduction in risks to actual

or potential receptors; or



    (ii) The constituent(s) is present in ground water that:



    (A) Is not a current or potential source of drinking water, and



    (B)  Is  not hydraulically connected with waters to which the hazardous

constituents  are  migrating or are likely to migrate in a concentration(s)

greater than an action level(s) specified according to Sec. 264.522; or



    (iii)  Remediation  of  the  release(s)  to  media cleanup standards is

technically impracticable.



    (3)  If  a  determination  is made pursuant to paragraph (d)(2) of this

section  the  Regional Administrator may require any alternative measure(s)

or standards he or she determines are necessary to protect human health and

the environment, including the control of further releases.



    (e) Compliance with media cleanup standards. The Regional Administrator

shall  specify in the remedy requirements for achieving compliance with the

media  cleanup  standards established under Sec. 264 525(d) (or alternative

levels under Sec. 264.525(d)(1)(v) or (d)(3)), as follows:



    (1) The Regional Administrator shall specify where compliance with such

standards or levels must be achieved, as follows:



    (i)  For  ground  water,  the  cleanup  standard(s)  or levels shall be

achieved  throughout  the  contaminated  ground  water, or, at the Regional

Administrator's discretion, when waste is left in place, up to the boundary

of a waste management area encompassing the original source(s) of release.

    The  Regional  Administrator  shall  specify  the  locations  at  which

ground-water monitoring wells must be located for purposes of:



    (A)  Monitoring  the  effectiveness  of  the  ground-water  remediation

program; and



    (B)  Demonstrating compliance with the ground-water cleanup standard(s)

or leve1(s).



    (ii)  For air, the cleanup standard(s) or level(s) shall be achieved at

the location of the most exposed individual, or other specified point(s) of

exposure closer to the source of the release, if determined by the Regional

Administrator  to be necessary to protect human health and the environment.

The  Regional  Administrator  shall  specify locations where air monitoring

devices   must   be  installed,  or  what  emission  modeling  or  testing,

atmospheric dispersion models, or other methods must be used to demonstrate

that  compliance  with  any  air  cleanup  standard(s) or level(s) has been

achieved at the point(s) of exposure.



    (iii)  For  surface water, the cleanup standard(s) or level(s) shall be

achieved  at  the  point where the release(s) enters the surface water. For

releases  that  have  accumulated  in surface water sediments, the Regional

Administrator   may,   as   necessary  to  protect  human  health  and  the

environment,  require that a cleanup standard(s) or level(s) be achieved at

designated  locations  in  the  sediments.  The Regional Administrator will

specify the locations where surface water or sediment samples must be taken

to  monitor surface water quality, and demonstrate that compliance with any

surface water cleanup standard(s) or leve1(s) has been achieved.



    (iv)  For soils, the cleanup standard(s) shall be achieved at any point

where  direct  contact  exposure  to  the  soils  may  occur.  The Regional

Administrator  will  specify  the  locations,  or  methods  for determining

appropriate  locations,  where  soil  samples  must be taken to demonstrate

compliance with the soil cleanup standard(s) or level(s).



    (v)  If the owner/operator is unable to obtain the necessary permission

to  undertake  corrective  action  beyond  the  facility  boundary, and can

demonstrate to the satisfaction of the Regional Administration that despite

the  owner/operator's  best  efforts.  she is as a result unable to achieve

media  cleanup standards or levels beyond the facility boundary, then media

cleanup  standards or levels must be achieved to the extent practicable, as

specified by the Regional Administrator.



    (2)  The Regional Administrator will specify in the remedy the sampling

and  analytical methods, any statistical analyses that may be required. and

the  frequency(s) of sampling or monitoring {pg 30879} that may be required

to  characterize  levels of hazardous constituents in ground water, surface

water, air or soils.



    (3) The Regional Administrator will specify in the remedy the length of

time during which the permittee must, in order to achieve compliance with a

media  cleanup  standard  or  level,  demonstrate  that  concentrations  of

hazardous  constituents have not exceeded the standard(s). Factors that may

be  considered  by  the  Regional Administrator in determining these timing

requirements include:



    (i) Extent and concentration of the release(s);



    (ii)  Behavior  characteristics  of  the  hazardous constituents in the

affected medium;



    (iii) Accuracy of monitoring or modeling techniques;



    (iv) Characteristics of the affected media; and



    (v)  Seasonal,  meteorological,  or  other  environmental variabilities

which may affect the accuracy of monitoring or modeling results



    (f) Conditional remedies. (1) If the criteria of Sec. 264.525(f)(2) are

met,  the  Regional  Administrator  may  select  a  conditional remedy that

protects   human  health  and  the  environment  under  plausible  exposure

conditions during the term of the permit.



    (2) A conditional remedy must:



    (i) Protect human health and the environment; and



    (ii)  Achieve  all  media  cleanup  standards  or  levels  as specified

pursuant  to  paragraphs  (d)  and  (e) of this section beyond the facility

boundary as soon as practicable; and



    (iii)   Prevent   further   significant   environmental   degration  by

implementing, as soon as practicable:



    (A)  treatment  or  other necessary engineering controls to control any

source(s) of releases; and



    (B)  engineered  measures  as  necessary to prevent further significant

migration of releases within the facility boundary.



    (iv) Institute effective institutional or other controls to prevent any

significant exposure to hazardous wastes at the facility; and



    (v)  Continue  the  monitoring  of  releases so as to determine whether

further significant environmental degradation occurs; and



    (vi) Include assurances of financial responsibility for the remedy; and



    (vii)  Comply  with  standards for management of wastes as specified in

Secs. 264.550-264.559 of this subpart.



    (3)  If  at  any  time  during the term of the permit, any condition of

paragraph  (f)(2)  of  this section is violated, the Regional Administrator

shall modify the permit to:



    (i)  Require the permittee to perform additional studies or actions, or

implement  additional  controls to achieve compliance with the requirements

of paragraph (f)(2) of this section; or



    (ii)  Require  additional studies, actions. or controls as necessary to

implement a remedy which meets the standards of Sec. 264.525(a).



    (4)  The  permit shall not be terminated until a remedy which meets the

standards  of  Sec.  264.525(a) has been implemented and certified complete

according to Sec. 264.530. Sec. 264.526 Permit modification for remedy.



    (a)  The  Regional Administrator shall modify the permit to specify the

remedy  selected according to Sec. 264.525, according to the procedures for

major permit modifications under Sec. 270.41.



    (b) The permit modification shall include, at a minimum, the following:



    (1)  Description  of  the  technical  features  of  the remedy that are

necessary  for  achieving  the  standards  for  remedies  specified in Sec.

264.525(a) and/or (f).



    (2)   All   media   cleanup  standards  established  pursuant  to  Sec.

264.525(d).



    (3) Requirements for achieving compliance with media cleanup standards,

pursuant to Sec. 264.525(e).

    (4)  Requirements  for  complying  with the standards for management of

wastes, pursuant to Secs. 264.550-264.559.



    (5) Requirements for removal, decontamination, closure, or post-closure

of  units,  equipment, devices or structures that will be used to implement

the remedy.



    (6)  A  schedule  for  initiating  and  completing  the major technical

features and milestones of the remedy.



    (7) Requirements for submission of reports and other information.



    (c)(1)  The schedule of compliance specified in the permit modification

shall  include  a  schedule  for  the  permittee  to  demonstrate financial

assurance for completing the remedy specified according to Sec. 264.526(b).

The  schedule  shall require the demonstration no later than 120 days after

the effective date of the permit modification.



    (2)  If  the  remedy  requires  closure of a hazardous waste management

unit,  and  the schedule of compliance for the remedy supplants or modifies

the  unit's  closure  or  post-closure plan, the Regional Administrator may

partially  or  fully  release  existing  financial  assurance  for closure,

post.closure, and third party liability required



    (d)  A  remedy specified in a permit modification may be separated into

phases.  A  remedy  phase  may consist of any set of actions performed over

time,  or  any  actions that are concurrent but located at different areas,

provided  that  the  actions  are  consistent  with  the final remedy. Sec.

264.527 Remedy design.



    (a)   The  Regional  Administrator  may  require  the  permittee,  upon

modification  of  the permit according to Sec. 264.526, to prepare detailed

construction  plans  and specifications to implement the approved remedy at

the  facility,  unless  such  plans  and  specifications  have already been

specified in the permit modification. Such plans shall be subject to review

and  approval  or  modification by the Regional Administrator, and shall be

developed   and  submitted  in  accordance  with  the  permit  schedule  of

compliance.  Upon approval by the Regional Administrator, the plan shall be

incorporated  expressly or by reference into part of the permit schedule of

compliance.  The plans and specifications must include, but are not limited

to, the following:



    (1)  Designs and specifications for units in which hazardous wastes and

non-hazardous  solid  wastes  will be managed, as specified in the approved

remedy.



    (2) Implementation and long-term maintenance plans.



    (3) Project schedule.



    (4) Construction quality assurance program.



    (b)  Upon  approval of the plans and specifications for the remedy, the

permittee shall-



    (1)   Implement   the   remedy   in   accordance  with  the  plans  and

specifications,  and consistent with the objectives of the remedy specified

in the permit;



    (2)  Place  the plans and specifications in the information repository,

if required under Sec. 270.36;



    (3)  Provide  written  notice of the availability for inspection of the

approved  plans and specifications for the remedy to all individuals on the

facility  mailing  list. If an information repository has not been required

pursuant  to  Sec.  270.36,  the  notice  shall specify where the plans and

specifications are available for inspection; and



    (4)  Revise  the  cost estimate used to demonstrate financial assurance

under Sec. 264.526(c), if necessary. Sec. 264.528 Progress reports.



    (a)  The  permittee  may  be  required by the Regional Administrator to

provide  {pg  30880}  progress  reports  during  the  design, construction,

operation  and  maintenance  of any remedy. Frequency and format of reports

shall  be  determined  by  the  Regional Administrator and specified in the

permit  schedule  of  compliance.  Such  reports  may  include, but are not

limited to:



    (1)  Summaries  of progress of remedy implementation, including results

of  monitoring  and  sampling activities, progress in meeting media cleanup

standards, and description of other remediation activities.



    (2) Problems encountered during the reporting period. and actions taken

or proposed to resolve the problems



    (3) Changes in personnel conducting or managing the remedial effort.



    (4) Project work for next reporting period.

    (5) Copies of laboratory reports and field sampling reports.



    (b)  All  raw data, such as laboratory reports, drilling logs and other

supporting  information  generated  from  the  remedial activities shall be

maintained  at  the  facility  (or  other location approved by the Regional

Administrator)  during  the  life  of the permit, including the term of any

reissued permits. Sec. 264.529 Review of remedy implementation.



    The  Regional  Administrator  shall periodically review the progress of

the remedy. Based on such review, the Regional Administrator may modify the

permit  schedule  of  compliance to require additional remedial measures to

ensure   prompt   completion,  safety,  effectiveness,  protectiveness,  or

reliability of the remedy. Sec. 264.530 Completion of remedies.



    (a)  Remedies  specified  pursuant  to Sec. 264.526 shall be considered

complete when the Regional Administrator determines that:



    (1)  Compliance  with all media cleanup standards (or alternate levels)

as   specified   in  the  permit  have  been  achieved,  according  to  the

requirements of Sec. 264.525(e); and



    (2) All actions required to control the source(s) of contamination have

been satisfied; and



    (3)  Procedures  specified  for  removal,  decontamination, closure, or

post-closure  care  of  units, equipment, devices or structures required to

implement the remedy have been complied with.



    (b)  Upon  completion  of the remedy, the permittee shall submit to the

Regional  Administrator,  by  registered mail, a request for termination of

the  corrective  action  schedule of compliance according to the procedures

for  Class  III  modifications  in Sec. 270.42. The request shall include a

certification  that  the  remedy  has been completed in accordance with the

requirements  of  Sec.  264.530(a), and that all other terms and conditions

specified  in  the  permit  pursuant  to Subpart S have been satisfied. The

certification  must  be  signed  by  the  permittee  and  by an independent

professional(s) skilled in the appropriate technical discipline(s).



    (c)  When,  upon  receipt of the certification, and in consideration of

public   comments   and   any  other  relevant  information,  the  Regional

Administrator  determines  that  the  corrective  measure  remedy  has bean

completed in accordance with the terms and conditions of the permit and the

requirements  for  remedy  completion  under  Sec. 264.530(a), the Regional

Administrator shall:

    (1)  Modify  the  permit to terminate the corrective action schedule of

compliance, according to the Class III procedures of Sec. 270.42.



    (2)  Upon  modification  of  the permit, release the permittee from the

requirements  for financial assurance for corrective action under Sec. 264.

500(c) and Sec. 264.90.



    (d)  If  a  remedy includes one or more identified phases, the Regional

Administrator may:



    (1)  Require  separate  certification  that  the  remedy phase has been

completed  as specified in the permit, to be signed by the permittee and an

independent   professional(s)   skilled   in   the   appropriate  technical

discipline(s); and



    (2) Release the permittee from the requirements for financial assurance

for  that  remedy  phase, if the Regional Administrator determines that the

remedy phase has been successfully completed. Sec. 264.531 Determination of

technical   impractiability.   Sec.   264.531  Determination  of  technical

impracticability.



    (a)  The  Regional  Administrator  may  determine, based on information

developed  by  the  permittee  or other information, that compliance with a

requirement(s)  for  the  remedy  is not technically practicable. In making

such determinations, the Regional Administrator shall consider:



    (1)   The   permittee's   efforts   to   achieve  compliance  with  the

requirement(s); and



    (2)  Whether other currently available or new and innovative methods or

technologies could practicably achieve compliance with the requirements.



    (b)  If  the  Regional  Administrator determines that compliance with a

remedy   requirement   is   not   technically   practicable,  the  Regional

Administrator  shall modify the permit schedule of compliance to specify as

necessary and appropriate:



    (1)  Further  measures that may be required of the permittee to control

exposure  of  humans  or  the  environment  to  residual  contamination, as

necessary to protect human health and the environment; and



    (2)  Alternate  levels  or measures for cleaning up contaminated media,

controlling   the   source(s)   of   contamination,   or   for  removal  or

decontamination  of  equipment,  units,  devices, or structures required to

implement the remedy which:



    (i) Are technically practicable; and



    (ii)  Are  consistent  with  the overall objectives of the remedy Secs.

264.532- 264.539 Reserved Sec. 264.540 Interim measures.



    (a)  If,  at  any  time the Regional Administrator determines, based on

consideration  of  the factors specified in Sec. 264.540(b), that a release

or, based on site-specific circumstances, a threatened release from a solid

waste  management unit(s) at the facility poses a threat to human health or

the  environment,  the  Regional  Administrator  may  specify in the permit

interim  measures  required of the permittee to abate, minimize, stabilize,

mitigate, or eliminate the release(s) or threat of release(s).



    (b)   The   following   factors  may  be  considered  by  the  Regional

Administrator in determining whether an interim measure(s) is required:



    (1) Time required to develop and implement a final remedy;



    (2) Actual or potential exposure of nearby populations or environmental

receptors to hazardous wastes (including hazardous constituents);

    (3)  Actual  or  potential  contamination of drinking water supplies or

sensitive ecosystems;



    (4)  Further  degradation  of  the  medium  which may occur if remedial

action is not initiated expeditiously;



    (5)  Presence of hazardous wastes (including hazardous constituents) in

drums,  barrels,  tanks,  or other bulk storage containers, that may pose a

threat of release;



    (6)  Presence  of  high levels of hazardous wastes (including hazardous

constituents) in soils largely at or near the surface, that may migrate;



    (7)  Weather  conditions  that  may  cause  hazardous wastes (including

hazardous constituents) to migrate or be released;



    (8)  Risks of fire or explosion, or potential for exposure to hazardous

wastes  (including  hazardous  constituents) as a result of an accident {pg

30881} or failure of a container or handling system;



    (9)  Other  situations  that  may  pose threats to human health and the

environment.

    (c) If the Regional Administrator determines that an interim measure is

necessary  pursuant  to  Sec.  264.540(a), the Regional Administrator shall

notify  the permittee of the necessary actions required. Such actions shall

be  implemented  as  soon  as practicable, in accordance with a schedule as

specified  by  the Regional Administrator. The Regional Administrator shall

modify  the  permit  schedule  of  compliance,  if  necessary,  to  require

implementation  of an interim measure, in accordance with the procedures of

Sec. 270.34 or Sec. 270.41, as appropriate.



    (d)  Interim  measures should, to the extent practicable, be consistent

with  the  objectives  of,  and contribute to the performance of any remedy

which  may be required pursuant to Sec. 264.525. Secs. 264.541-549 Reserved

Sec. 264.550 Management of wastes.



    (a)  All  solid  wastes which are managed pursuant to a remedy required

under  Sec.  264.525,  or  an  interim measure required under Sec. 264.540,

shall be managed in a manner:



    (1) That is protective of human health and the environment; and



    (2)   That   complies   with   applicable   Federal,  State  and  local

requirements.

    (b) The Regional Administrator shall specify in the permit requirements

for  units  in  which  wastes  will  be managed, and other waste managament

activities, as determined by the Regional Administrator to be necessary for

protection  of human health and the environment. Sec. 264.551 Management of

hazardous wastes.



    (a)  Except  as  Provided  herein and in paragraphs (b) and (c) of this

section  any  treatment,  storage  or  disposal  of  listed  or  identified

hazardous waste necessary to implement a remedy or an interim measure shall

be  in  accordance  with the applicable standards of 40 CFR parts 262, 264,

268 and 269. Requirements for closure contained in subpart G of 40 CFR part

264,  except  for Sec. 264.111, may be waived by the Regional Administrator

for units created for the purpose of managing corrective action wastes.



    (b)(1)  For temporary units (except for incinerators and other non-tank

thermal  treatment  units)  in  which  hazardous  wastes  will be stored or

treated, the Regional Administrator may determine that a design, operating,

or  closure standard(s) applicable to such unit(s) solely by regulation may

be  replaced  by  alternative  requirements  which  are protective of human

health and the environment.



    (2)  Any  temporary  unit  to which alernative requirements are applied

according to paragraph (b)(1) of this section shall:



    (i)  Be  operated  for a period not exceeding 180 calendar days, unless

the period is extended under Sec. 264.551(b)(3) below; and



    (ii) Be located at the facility; and



    (iii)  Be  used  only  for  treatment  or  storage  of hazardous wastes

(including  hazardous  constituents),  or  other  solid  wastes  that  have

originated within the boundary of the facility.



    (3)  The  Regional  Administrator may grant an extension to the 180-day

period  of a temporary unit if hazardous wastes must remain in the unit due

to   unforeseen,   temporary,   and   uncontrollable   circumstances.   The

owner/operator  must request this extension as a Class I modification, with

Director approval, under the procedures of Sec. 270.42.



    (4)  In  establishing  standards  to be applied to temporary units, the

Regional Administrator shall consider the following factors:



    (i) The 1ength of time such unit(s) will be in operation.

    (ii) Type of unit, and volumes of wastes to be managed.



    (iii) Potential for releases from the unit(s).



    (iv)  Physical and chemical characteristics of the wastes to be managed

in the unit(s).



    (v)  Hydrogeological and other relevant environmental conditions at the

facility which may influence the migration of any potential releases.



    (vi)  Potential  for  exposure of humans and environmental receptors if

releases were to occur from the unit(s).



    (5)  The  Regional Administrator shall specify in the permit the length

of  time  that  such units will be allowed to operate, and specific design,

operating, and closure requirements for the unit(s).



    (c)  For  the purposes of implementing remedies under this subpart, the

Regional  Administrator  may  designate  an  area  of  contamination  as  a

corrective action management unit.



    (1)  Movement  or  consolidation  of  wastes within a corrective action

management  unit  will  not  constitute  placement of hazardous wastes in a

hazardous waste management unit.



    (2)  Consolidation  of  wastes  within the corrective action management

unit  will  not  constitute  creation  of  a  new,  replacement, or lateral

expansion of a hazardous waste management unit.



    (3)  In  making  determinations  as  to  whether  a  corrective  action

management  unit  is  appropriate  for implementing a remedy at a facility,

and/or  the nature and configuration of a corrective action management unit

at a facility, the Regional Administrator may consider the following:



    (i)  The  nature, extent and location of surficial contamination at the

facility;



    (ii)  The  potential benefits of a corrective action management unit in

achieving  remedial objectives for the facility, including (but not limited

to):



    (A) Expediting the timing of remedy implementation; and



    (B)  Enhancing  the  effectiveness,  cost-effectiveness, reliability or

protectiveness of a remedy;



    (iii) The practicability of alternative remedial approaches; or



    (iv) Other relevant factors.



    (4)  The requirements of subpart G of 40 CFR part 264 will not apply to

corrective action management units. The Regional Administrator will specify

in  the  permit  closure  requirements for any corrective action management

unit, in consideration of the following factors:



    (i) Unit characteristics;



    (ii) Volume of wastes which will remain after closure;



    (iii) Potential for releases from the unit;



    (iv) Physical and chemical characteristics of the wastes;



    (v)  Hydrological  and  other  relevant environmental conditions at the

facility which may influence the migration of any potential releases; and

    (vi)  Potential  for  exposure of humans and environmental receptors if

releases were to occur from the unit.



    (5)  Closure  requirements  specified  for corrective action management

units under paragraph (c)(3) of this section shall:



    (i) Minimize the need for further maintenance; and



    (ii)  Control,  minimize,  or  eliminate,  to  the  extent necessary to

protect  human health and the environment, post-closure escape of hazardous

waste,  hazardous constituents, leachate, contaminated runoff, or hazardous

waste  decomposition  products  to  the  ground or surface waters or to the

atmosphere.



    (6)  The Regional Administrator will specify in the permit post-closure

requirements  for  any  corrective  action management unit, as necessary to

protect   human  health  and  the  environment,  including  monitoring  and

maintenance  activities and the frequency with which they will be performed

to  ensure  the  integrity  of  the  {pg  30882} cap, final cover, or other

containment system. Sec. 264.552 Management of non-hazardous solid wastes.



    (a)  Treatment,  storage  and  disposal  of  non-hazardous solid wastes

pursuant  to  a remedy or interim measure required under this subpart shall

be  in  accordance  with  applicable  technical  standards  for solid waste

management  as  specified  in  regulations  promulgated  pursuant  to  RCRA

subtitle D.



    (b)  For  any  unit in which non-hazardous solid wastes will be managed

pursuant  to  a  remedy  or interim measure, the Regional Administrator may

specify  additional  design  and  operating  standards  for the unit(s), as

necessary  to  protect  human  health  and  the environment. In determining

appropriate  design and operating requirements for such units, the Regional

Administrator   shall   consider   the   factors   specified   under   Sec.

264.551(b)(2).   Secs.   264.553-264.559  Reserved  Sec.  264.560  Required

notices.



    (a)  Notification  of  ground-water  contamination.  If at any time the

permitted  discovers  that  hazardous constituents in ground water that may

have  been released from a solid waste management unit at the facility have

migrated  beyond the facility boundary in concentrations that exceed action

levels (as defined under Sec. 264.521), the permittee shall, within fifteen

days of discovery, provide written notice to the Regional Administrator and

any  person who owns or resides on the land which overlies the contaminated

ground water.

    (b)  Notification  of  air  contamination. If at any time the permittee

discovers  that  hazardous  constituents in air that may have been released

from a solid waste management unit at the facility have or are migrating to

areas  beyond  the  facility  boundary in concentrations that exceed action

levels (as defined under Sec. 264.521), and that residences or other places

at  which  continuous,  long-term exposure to such constituents might occur

are  located within such areas, the permittee shall, within fifteen days of

such discovery:



    (1) Provide written notification to the Regional Administrator; and



    (2) Initiate any actions that may be necessary to provide notice to all

individuals who have or may have been subject to such exposure.



    (c)  Notification  of  residual  contamination.  If hazardous wastes or

hazardous  constituents in solid waste management units, or which have been

released  from  solid waste management units, will remain in or on the land

after  the  term  of the permit has expired, the Regional Administrator may

require  the  permittee to record, in accordance with State law, a notation

in  the  deed to the facility property or in some other instrument which is

normally  examined during title search that will, in perpetuity, notify any

potential  purchaser  of  the  property  of  the  types, concentrations and

locations of such hazardous wastes or hazardous constituents.



PART  265-INTERIM  STATUS  STANDARDS  FOR OWNERS AND OPERATORS OF

HAZARDOUS

WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES



    6. The authority citation for part 265 continues to read as follows:



    Authority: 42 U.S.C. 6905, 6924, and 6925.



    7.  In  40  CFR  part  265,  subpart  G,  it  is proposed to amend Sec.

265.112(b)  by  adding  new  paragraph (b)(8). and to amend Sec. 265.113 by

redesignating  paragraphs  (a)(1)(ii)  as  (a)(1)(iii)  and  (b)(1)(ii)  as

(b)(1)(iii), and by adding new paragraphs (a)(1)(ii) and (b)(1)(ii) to read

as follows: Sec. 265.112 Closure plan, amendment of plan.



    (b)



    (8)  Information  which  complies  with  the  requirements  of  40  CFR

270.14(d)  for  all  solid  waste  management  units  at the facility. Sec.

265.113 Closure, time allowed for closure.



    (a)

    (1)



    (ii)  Corrective  action  required  at  the  unit or the facility under

subpart S will delay the completion of partial or final closure; or



    (b)



    (1)



    (ii)  Corrective  action  required  at  the  unit or the facility under

subpart S will delay the completion of partial or final closure: or



PART  270-EPA  ADMINISTERED  PERMIT  PROGRAMS:  THE  HAZARDOUS WASTE

PERMIT

PROGRAM



    8. The authority citation for part 270 continues to read as follows:



    Authority: 42 U.S.C. 6905, 6912, 6925, 6927, and 6974



    9.  It  is  proposed to amend paragraph (c) of Sec. 270.1 by adding the

following  introductory  text  immediately before the sentence which begins

''The  denial  of  a  permit for the active life ,'' as follows: Sec. 270.1

Purpose and scope of these regulations.



    (c)  Owners  and  operators  must also have permits covering any period

necessary to comply with the requirements of subpart S of part 264.



    10.  It  is  proposed  to  amend Sec. 270.30(l) by adding new paragraph

(l)(12)  to  read  as  follows:  Sec.  270.30  Conditions applicable to all

permits.



    (l)



    (12)  Information  pertinent  to corrective action requirements. (i) If

the  permittee  discovers additional solid waste management units or learns

of  releases  of  hazardous  wastes (including hazardous constituents) from

previously  identified  or newly discovered solid waste management units at

the  facility,  the permittee shall submit the following information to the

Director:



    (A) Identification of additional solid waste management unit(s). Within

thirty  days  of  the receipt of information about a previously unknown and

unreported  solid  waste  management unit at the facility (as defined in 40

CFR  264.501),  the permittee shall submit the following information to the

Director:



    (1)  The  location of the unit on the topographic map submitted as part

of  the  part  B  application  in accordance with 40 CFR 270.14(b)(19) or a

topographic map of comparable scale which clearly indicates the location of

the unit in relation to other solid waste management units at the facility.



    (2) Designation of type of unit.



    (3) General dimensions of the unit.



    (4) When the unit was operated.



    (5)  Specification of all wastes that have been managed in the unit, if

available.



    (6)  All  available  information pertaining to any release of hazardous

wastes (including hazardous constituents) from the unit.



    (B)  Sampling and analysis data. The Director may require the permittee

to  perform  sampling  and  analysis of ground water (which may involve the

installation  of  wells),  soils,  surface  water,  or air, as necessary to

determine  whether  a release(s) from such unit(s) {pg 30883} has occurred,

is likely to have occurred, or will likely occur.



    (C)  Releases  of hazardous waste. If the permittee discovers a release

of  hazardous  wastes (including hazardous constituents) from a solid waste

management  unit at the facility that may pose a threat to human health and

the  environment, the permittee shall, within twenty days of the discovery,

submit the following information to the Director:



    (1) Identification of the solid waste management unit(s) from which the

release has occurred, to include the type of unit, and location of the unit

clearly indicated on a facility map; and



    (2)  Any  other information currently available concerning the release,

including  potential exposure pathways. controls already imposed to address

the release, and any action planned for further cleanup.



    (ii)  Based  upon information supplied under (A), (B), or (C) above the

Director  may,  as  necessary, require further investigations or corrective

measures  in  accordance with the standards for corrective action specified

in  40  CFR  subpart  S. Such additional activities shall, if necessary, be

specified by modifying an existing schedule of compliance according to Sec.

270.34(c), or by initiating a permit modification according to Sec. 270.41.



    11.  Section  270.33 is amended by adding the following sentence at the

end  of  paragraph  (a)  to  read  as  follows:  Sec.  270.33  Schedules of

Compliance



    (a)  Schedules  of compliance for corrective action are governed solely

by Sec. 270.34.



    12.  It  is proposed to amend 40 CFR part 270, subpart C, by adding new

Sec.  270.34  to  read as follows: Sec. 270.34 Schedules of compliances for

corrective action.



    Schedules  of  compliance  for  corrective  action are governed by this

section and not Sec. 270.33.



    (a) The Director may include a schedule of compliance in the permit for

purposes of specifying the terms and conditions necessary for the permittee

to  comply with the requirements of subpart S of part 264. Permit schedules

of  compliance issued under this section shall contain terms and conditions

deemed  by  the  Director  to  be necessary to protect human health and the

environment.

    (b)  The  permittee  shall  adhere  to  the  schedules specified in the

permit.  If  at  any time the permittee determines that schedules cannot be

met,  the permittee shall, within 15 days of such determination, notify the

Director  and submit a request for a permit modification under Sec. 270.42,

with an explanation of why the current schedule cannot be met.



    (c)  The  Director  may  modify the permit to include conditions in the

schedule  of  compliance  as  necessary  to comply with the requirements of

subpart S of part 264. The following procedures will be followed unless the

Director  determines  instead  that  it is appropriate to modify the permit

pursuant to Sec. 270.41(a)(5)(ix):



    (1)  The  Director will notify the permittee in writing of the proposed

modification. Such notice will:



    (i) Describe the exact change(s) to be made to the permit conditions;



    (ii) Provide an explanation of why the modification is needed; and



    (iii)  Provide  notification  of  the  date  by  which  comments on the

proposed  modification  must  be  received. Such date will not be less than

twenty  days  from the date the notice of proposed modification is received

by  the  permittee,  or  after  the  public  notice is published under Sec.

270.34(c)(2);



    (iv)  Provide notification that supporting documentation or data may be

available for inspection at the Regional or State office; and



    (v)  Include the name and address of an Agency contact to whom comments

may be sent.



    (2) The Director shall:



    (i)  Publish  a  notice  of  the  proposed  modification in a newspaper

distributed in the locality of the facility, which includes notice of items

(1)(i)-(v);



    (ii)  Mail  a notice of the proposed modification to all persons on the

facility  mailing  list  maintained according to 40 CFR 124.10(c)(1)(viii).

Such notice will include items (1)(i)-(v), and shall be mailed concurrently

with notice to the permittee;



    (iii)  For  facilities which have established an information repository

pursuant  to  Sec.  270.36,  the Director shall place a notification of the

proposed  modification,  including  items  (1)(i)-(v),  in  the information

repository concurrently with actions taken under (i)-(ii).



    (3)  If  the  Director  receives  no  written  comment  on the proposed

modification,  the  modification  will become effective five days after the

close  of  the  comment  period;  the  Director  will  promptly  notify the

permittee  and individuals on the facility mailing list in writing that the

modification  has  become  effective, and will place a copy of the modified

permit  in the information repository if a repository is maintained for the

facility.



    (4)   If   the  Director  receives  written  comment  on  the  proposed

modification,  the Director shall make a final determination concerning the

modification  within  thirty  days  after  the end of the comment period if

practicable. The Director shall then:



    (i)  Notify  the  permittee  in  writing  of  the  final decision. Such

notification shall:



    (A)  Indicate the effective date of the modification, which shall be no

later  than  fifteen  days  after  the  date  of  notification of the final

modification decision,

    (B)   Include  an  explanation  of  how  comments  were  considered  in

developing the final modification, and



    (C) Provide a copy of the final modification;



    (ii)  Provide  notice  of  the  final  modification decision, including

paragraphs (c)(4)(i)(A) and (i)(B) of this section, in a newspaper of local

distribution in the vicinity of the facility; and



    (iii)  Place  a  copy  of  items  (i)(A)-  (i)( C)  in  the information

repository for the facility if such a repository is maintained.



    (5)  Modifications  initiated  and  finalized  by  the  Director  using

procedures in Sec. 270.34(c) are not subject to administrative appeal.



    B.  It  is  proposed to amend 40 CFR part 270, subpart C, by adding new

Sec. 270.36 Information repository.



    (a)  At  any  time during conduct of investigations or other activities

required  under part 264, subpart S, the Director may require the permittee

to  establish  and  maintain  an  information repository for the purpose of

making accessible to interested parties documents, reports and other public

information  developed  pursuant  to investigations and activities required

under part 264, subpart S.



    (b)  The  information  repository shall contain all documents, reports,

data  and  other  information  which  the Director deems relevant to public

understanding  of  the  activities,  findings and plans for such corrective

action initiatives.



    (c)  The information repository shall, when feasible, be located within

reasonable  distance  of the facility, or if not feasible, at the facility.

The  repository  shall be accessible to the public during reasonable hours,

as required by the Director.



    (d)  In  the  permit schedule of compliance, the Director shall specify

requirements  for informing the public about the information repository. At

a  minimum,  written notice about the information repository shall be given

to {pg 30884} all individuals on the facility mailing list.



    (e)  Information  regarding procedures for submission of comments shall

be made available at the repository.



    14.  It  is  proposed to amend Sec. 270.41 by revising the introductory

text and by adding new paragraph (a)(5)(ix) to read as follows: Sec. 270.41

Modification or revocation and reissuance of permits.



    When  the  Director receives any information (for example, inspects the

facility,  receives  information  submitted by the permittee as required in

the  permit  (see  Sec.  270.30),  receives  a  request for modification or

revocation  and  reissuance  under  Sec. 124.5, or conducts a review of the

permit  file)  he  or  she  may determine whether one or more of the causes

listed  in  paragraphs  (a)  and  (b)  of this section for modification, or

revocation  and reissuance or both exist. If cause exists, the Director may

modify  or  revoke  and  reissue  the  permit  accordingly,  subject to the

limitations  of  paragraph  (c) of this section, and may request an updated

application  if  necessary.  When a permit is modified, only the conditions

subject  to modification are reopened. If a permit is revoked and reissued,

the  entire  permit  is  reopened and subject to revision and the permit is

reissued  for a new term. (See 40 CFR 124.5(c)(2).) If cause does not exist

under this section, the Director shall not modify or revoke and reissue the

permit,  except  on  request  of  the  permittee or in accordance with Sec.

270.34(c).  If  a  permit  modification  is requested by the permittee, the

Director  shall  approve or deny the request according to the procedures of

40  CFR  270.42.  The  Director  may  also  modify  the  permit schedule of

compliance  for  corrective  action under the procedures of Sec. 270.34(c).

Otherwise, a draft permit must be prepared and other procedures in part 124

(or procedures of an approved State program) followed.



    (a)



    (5)



    (ix)  The Director determines good cause exists for modification of the

permit for the purposes of compliance with subpart S of part 264.



    15.  It  is  proposed to revise paragraphs (b)(3)(i) and (c)(3)(vii) of

Sec. 270.60 as follows: Sec. 270.60 Permits by rule.



    (b)



    (3)



    (i) Complies with 40 CFR subpart S; and



    (c)



    (3)

    (vii)  for  NPDES permits issued after November 8, 1984, 40 CFR subpart

S.



PART 271- REQUIREMENTS FOR AUTHORIZATION OF STATE HAZARDOUS WASTE

PROGRAMS



    16. The authority citation for part 271 continues to read as follows:



    Authority: 42 U.S.C. 6905, 6912(a), and 6926.



    17. It is proposed to amend Sec. 271.1(j) by adding the following entry

in  Table  1  in  chronological  order  by  date of publication: Sec. 271.1

Amended



 Table 1-Regulations Implementing the Hazardous and

       Solid Waste Amendments of 1984



 Date                   July 27, 1990

 Title of Regulation    Corrective Action for Solid Waste

                          Management Units.