Tuesday
August 30., 1988
and
40 GFR Parts 257
Solid Waste Disposal
Proposed Rule
258
Facility Criteria;
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33314
Federal Register / Vol. 53. No. 168,
Proposed Rules
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Parts 257 and 258
[FRL-3227-7]
Solid Waste Disposal Facility Criteria
AGENCY: Environmental Protection
Agency (1SPA).
ACTION: Proposed rule.
SUMMARY: The Environmental Protection
Agency today is proposing revisions to
the Criteria for Classification of Solid
Waste Disposal Facilities and Practices
set forth in 40 CFR Part 257. These
revisions were developed in response to
the 1984 Hazardous and Solid Waste
Amendments to the Resource
Conservation and Recovery Act
(RCRA). This proposed action would
amend Part 257 by including information
requirements for certain solid waste
disposal facilities and by excluding
municipal solid waste landfills
(MSWJLFs) from Part 257. In addition,
this action would add a new Part 258,
which spells out specific requirements
forMSWLFs.
Amended Part 257 would establish
notification and exposure information
requirements for owners and operators
of industrial solid waste disposal
facilities iind construction/demolition
waste landfills. The new Part 258 sets
forth revised minimum Criteria for
MSWLFs, primarily in the form of
performance standards, including
location restrictions, facility design and
operating criteria, ground-water
monitoring requirements, corrective
action requirements, financial
assurance, and closure and post-closure
care requirements.
, EPA believes that the provisions in
today's proposal are necessary for the
protection of human health and the
environment and take into account the
practicable capability of owners and
operators of municipal solid waste
landfills. The Agency is requesting
comment on the overall approach
proposed and on specific components of
the proposal.
Today's proposal also is intended to
fulfill a portion of EPA's mandate under
section 405(d) of the Clean Water Act
(CWA) to promulgate regulations
governing the use and disposal of
sewage sludge. Under today's proposal,
Part 258 would be co-promulgated under
the authority of the CWA; this authority
would apply to all municipal solid waste
facilities in which sewage sludge is co-
disposed with household wastes. A
separate regulation for sludge monofills
(landfills in which only sewage sludge is
disposed of] is being prepared for future
proposal under 40 CFR Part 503.
DATES: Comments on this proposed rule
must be submitted on or before October
31,1988.
Public hearings are scheduled as
follows:
(1) October 13,1988, 9:00 a.m. to 4:30
p.m., at the Sheraton National Hotel, 900
Orme Street, Arlington, VA. 22204, (703)
521-1900.
(2) October 18,1988, 9:00 a.m. to 4:30
p.m., at the Sheraton Century Center
Hotel, 2000 Century Boulevard, NE,
Atlanta, Georgia. 30345-3377, (404) 325-
0000.
(3) October 20,1988, 9:00 a.m. to 4:30
p.m., at the Sheraton Anaheim, 1015
West Ball Rd., Anaheim, CA. 92802,
(714) 778-1700
(4) October 25,1988, 9:00 a.m. to 4:30
p.m., at the O'Hare Hilton Hotel, P.O.
Box 66414, O'Hare International Airport,
Chicago, Illinois. 60666 (312) 686-8000.
The meetings may be adjourned
earlier if there are no remaining
comments. Requests to present oral
testimony should be received by EPA at
least 10 days before each public
meeting.
A block of rooms has been reserved at
the above mentioned hotels for the
convenience of individuals requiring
lodging. Please make room reservations
directly with the hotel and refer to the -
EPA hearings. The hearing registration
will be at 8:00 a.m., with the hearings
beginning at 9:00 a.m. and running until
4:30 p.m., unless concluded earlier.
Anyone wishing to make a statement at
the hearing must notify, in writing,
Public Participation Officer, Office of
Solid Waste (WH-562A), U.S.
Environmental Protection Agency, 401M
Street, SW; Washington, DC 20460.
Those wishing to make oral
presentations must restrict them to 15
minutes and are encouraged,to have
written copies of their complete
comments for inclusion in the official
record.
The Agency is tentatively planning to
coordinate these Subtitle D Criteria
public meetings with the public meetings
on EPA's Draft National Strategy for
Municipal Waste which is expected to
be issued in the near future. EPA will
announce these meetings in a separate
FR notice. For information on the
strategy please see 53 FR 13316 (April,
22,1988).
ADDRESSES: Commentors must send an
original and two copies of their
comments to: RCRA Docket Information
Center, (OS-305), U.S. Environmental .
Protection Agency Headquarters, 401M
Street, SW; Washington, DC 20460.
Comments should include the docket
number F-88-CMLP-FFFFF. The public
docket is located at EPA Headquarters
(sub-basement) and is available for
viewing from 9:00 a.m. to 4:00 p.m.,
Monday through Friday, excluding
Federal holidays. Appointments may be
made by calling (202) 475-9327. Copies
cost $.15/page. -
FOR FURTHER INFORMATION CONTACT:
For general information, contact the
RCRA/CERCLA Hotline, Office of Solid
Waste, U.S. Environmental Protection
Agency, 401 M Street, SW; Washington,
DC 20460, (800) 424-9346, toll-free, or
(202) 382-3000, local in the Washington,
DC metropolitan area.
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; Register ;.'./ 'Vol. asf No; 168,
August SO, 1988 / -'$&ip8s6& 3Me's
33315
Pof information on specific aspects of
this proposed rule, contact either Allen
Geswein or Paul Cassidy, Office of Solid
Waste (QS-323), U.SvEnvironmental
Protection Agency, 401M Street, SW.,
Washington, DC 20460, (202) 382^4859 Or
382-3346.
SUPPLEMENTARY INFORMATION:
Copies of the following Subtitle D
, Criteria background documents are
available for purchase through the
National Technical Information Service
{NTIS), U.S. Department of Commerce,
5285 Port Royal Road, Springfield,
Virginia 22161, (703 J 487-4650. EPA and
NTIS numbers and NTIS prices are •_.
listed below. Documents cannot be
obtained directly from EPA.
{1} U.S. EPA, Office of Solid Waste
(OSW). Notification Requirements for
IndustrialSolid Waste Disposal
Facilities-^Griteria for Classification of
Solid Waste Disposal Facilities and
Practices [40 CFR Part 257)—Subtitle D
of the Resource Conservation and
Recovery Act (RCRA). August 1988
(draft). EPA/53Q-SW-88-044, PB88-242
508, $12.95.
(2) U.S. EPA, OSW. Location
Restrictions (Subpart B)—Criteria for
Municipal Solid Waste Landfills (40 CFR
Part 258)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). July 1988 (draft), EPA/530-.SW-
88-036, PB88-242 425, $19.95.
(3) U.S. EPA, OSW. Operating Criteria
(Subpart C)-^-Griteria for Municipal
Solid Waste Landfills (40 GFR Part
258)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). July 1988 (draft). EPA/530-SW-
S8-037, PB88-242 433, $19.95.
(4) U.S. EPA, OSW. Closure/Post-
Closure Care and Financial
Responsibility Requirements (Subpart C,
§§ 258.30--258.32}—Criteria for
Municipal Solid Waste Landfills (40 CFR
Part 258)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). July 1988 (draft). EPA/530-SW-
88-041, PB88-242 474, $19.95.
(5) U.S. EPA, OSW. Design Criteria
(Subpart D)—Criteria for Municipal
Solid Waste Landfills (40 CFR Part
256)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA); July 1988 (draft). EPA/530-SW-
88-042, PB88-242 482, $19.95.
;(8) U.S. EPA, OSW, Ground-Water
Monitoring and Corrective .Action
(Subpart E}—Criteria for Municipal
Solid Waste Landfills (40 CFR Part
258)—Subtitle D of the Resource
'. Conservation and Recovery Act
(RCRA). fuly 1988 (draft), EPA/530-SW-
88-043, PB88-242 490, $19.95.
(7) US. EPA, OSW, Case Studies on
Ground-Water and Surface Water
Contamination from Municipal Solid
Waste Landfills—Criteria for Municipal
Solid Waste Landfills (40 CFR Part
258)—Subtitle D of the Resource ^
Conservation and Recovery Act •
(RCRA). July 1988 (draft). EPA/530-SW-
88-040, PB88-242 466, $14.95.
(8) U,'S. EPA, OSW. Summary of Data
on Municipal Solid Waste Landfill
Leachate Characteristics—Criteria for
Municipal Solid-Waste Landfills (40 CFR
Part 258)—-Subtitle D of the Resource -
Conservation and Recovery Act
(RCRA), July 1988 (draft). EPA/530-SW-
88-038, PB88-242 441, $19.95.
(9) U.S.EPA, OSW. Updated Review
of Selected Provisions of State Solid
Waste Regulations—Criteria for
Municipal Solid Waste Landfills (40 CFR
Part 258}—Subtitle D of the Resource
Conservation and'Recovery Act
(RCRA). July 1988 (draft). EPA/530-SW-
88-039, PB88-242 458, $14.95,
(10) U.S. EPA, OSW. Regulatory :
.Impact Analysis (RIA) of Proposed
Revisions to Subtitle D Criteria for
Municipal "Solid Waste Landfills-
Criteria for Municipal Solid Waste
Landfills (40 CFRPart 2S8)-^-Subtitle D
of the Resource Conservation and
Recovery Act (RCRA). July 1988 (draft).
EPA/530-SW-88-045, PB88-242 516,
$25.95.
All documents' can bemicrofiched for
Preamble'Outline
I. Authority
n. Background .-"•'.
A. Current Subtitle D Criteria .
6. Hazardous and Solid Waste Amendments
of 1984
1. Subtitle D Study and Report to Congress
2. Criteria Revisions -."
3. Implementation and Enforcement
C. Current Sewage Sludge Criteria
III. Nature and Scope of the Problem
A. EPA Studies of Solid Waste Management
1. Analysis of Solid Waste Characteristics
2. Review of Waste Disposal Practices
3. Assessment of Impacts
B. State Controls on Solid Waste
Management
C. Need for Revisions to the Part 257 Criteria
IV, Public Participation in This Rulemaking
V. Scope and Structure of Today's. Proposal
A. Scope of the Existing Part 257
B. Scope of Today's Proposal ,
C. Structure of Today's Proposal
D. Scope and Effect of Today's Proposal on
MSWLFs That Co-dispose of Sludge
VI. General Approach to Today's Proposal
VII. Major Issues " '
A. Ground-Water Resource Value
B. Exclusion of Closed MSWLEs
C. Practicable Capability
D. Extent of the Criteria Revisions
E. Requirements for Facilities Other Than
MSWLFs:
VIII. Amendments to Part 257
A. §§ 257.1-2 Conforming Changes to Part 257
B. i§ 257.3^4 Revisions to Ground-Water
Requirements
C. § 257.S, Notification and Exposure,
Information Requirements
IX. Section-by-Section Analysis o! Part 258 ,
A. Subpa:rt A--General . ,.
1. § 258i.l Purpose, Scope, and -
Applicability ; •
2.§ 258u2 Definitions
3. § 25fii.3 Consideration of Other Federal
Lawsi . . -.'.•••_"
B. Subpai't B—-Location RestrictionB
1.1258.10 Airport Safety
2. §25lBi.ll Floodplains
3. §2581.12 Wetlands • . -V .
4. |258i.l3 "Fault Areas•-."
' 5.12581.14 Seismic Impact Zones
6. §2581.15 Unstable Areas
C.SubpairtC—Operating Criteria
1. § 2581.20 Procedures for Excluding the
Receipt of Hazardous Waste .
2. § 2581.21 Cover Material Requirements
3V| 2581.22 Disease Vector Control
4. §25£l.23 Explosive Gases Control
5. §2561.24 AirCriteria
6.;§25£l.25 Access Requirements
7. §125(1.26 Run-on/Run-off Control
SysKsm? •',-
8.12581,27 Surface Water Requirements
9. § 2581.28 Uquids Reslrictions
10.12518.29 Recordkeeping Requiremerits
-11, i 2518.30 Closure Criteria " ,
• 12. § 2Si8^1 Post-closure Care
. Reqjjiirements
13. § 2EI8.32 Financial Assurance Criteria
D. Subpart D—Design Criteria :
1. §25 JI.40 Overview of Proposed
Stajaiards ,
2. Rationale forttopbsed Approach
. .3. Alteiaiatives Considered ,
4. hnplementation of Performance Standard
for New Units
E. Subpairt E—Ground Water Monitoring and
CoroBctive Action
1.1258.50 Applicability
2. §25831-55 Overview of Ground-Water
.Moaltoring Requirements :
3. |25!l.56 Assessment of Corrective
Meaijure's . -. "•:. ,' '
4.1258.57 Selection of Remedy and
^EstalDlishmerit of Groimd-Water
ProUsction^Standard '
5.1 258.58 Implementation of the ,
, CorriBctive Action Program
8. Relationship to Other Programs
X. Effective Date, Implementation, and
-Enforcement of the Revised Criteria
A, Effective Date of fee Revised Criteria
1. Eighteen-month Period
2. Two-stage Approach
B. Review of State Permit Programs
" C.Enforcemenl of the RevisedCriteria
l: Citizer,: Suits ,
2. Federal Enforcement
D. Other Implementation Issues
1. Implementation Strategy _'
2. Co-disposal of Sewage Sludge
XI. Regulatory Requirements -
A. Executive Order No. 12291
1.Purpose ; ..;'. ...--"'
2. Regvilatpry Alternatives
3. Cost Analysis
. 4. Economic Impact Analysis
5. Risk Assessment
B.ilegulBltory Flexibility Act
1. Mefliodology .
2. Results
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ede!ra]1 Re8*ster / v°l-' 53. 'N°- *68, Tuesdayiagu8t30,1988/ • Rrojpoaed Rules
C. Limitations
D, Paperwork Reduction Act
XII. References
A. Background Documents
B. Regulatory Impact Analysis
C. Guidance Documents
D. Other References
X11I. List of Subjects in 40 CFR Parts 257 and
253
A. Part 257
B. Part 258
I. Authority
These regulations are being proposed
under the authority of sections 1008,
4004, and 1010 of the Resource
Conservation and Recovery Act of 1976.
Section 1008 directed EPA to publish
guidelines for solid waste management,
including criteria that define solid waste
management practices that constitute
open dumping and are prohibited under
Subtitle D of RCRA. Section 4004 further
required EPA to promulgate regulations
containing criteria for determining
which facilities are sanitary landfills
and which are open dumps. In response,
EPA promulgated the "Criteria for
Classification of Solid Waste Disposal
Facilities and Practices" (40 CFR Part
257) in 1979. Section 4010, added by the
Hazardous and Solid Waste
Amendments of 1984 (HSWA), directs
EPA to revise those Criteria
promulgated under sections 1008 and
4004 for facilities that may receive
household hazardous waste (HHW) or
small quantity generator (SQG)
hazardous waste.
For municipal solid waste landfills hi
which sewage sludge is disposed of
together with household wastes, the Part
268 regulations also are being proposed
under the authority of section 405 (d)
and (e) of the CWA. Section 405
regulates the use and disposal of sewage
sludge generated by treatment works
treating domestic sewage. Section 405
requires that EPA develop standards for
sludge use and disposal, including: An
identification of the major use and
disposal practices, factors to be taken
into account in'determining applicable
measures and practices for each use or
disposal, and concentrations of
pollutants that interfere with each use or
disposal. When the CWA was amended
in February 1987, additional
requirements were added to section 405.
Congress directed EPA to identify toxic
pollutants that may be present in
sewage sludge in concentrations that
may adversely affect public health and
the environment and to establish
numerical limitations and management
practices for each identified pollutant
for each use of disposal option. The
numerical limitations and management
practices are to be adequate to protect
public health and the environment from
any reasonably anticipated adverse
effects of each pollutant. Further, the
amendments require that these section
405(d) sludge standards be implemented
through National Pollutant Discharges
Elimination System (NPDES) permits
issued to publicly owned treatment
works (POTWs) or other treatment
works treating domestic sewage unless
the standards have been included in a
permit issued under RCRA Subtitle C;
the Safe Drinking Water Act; the Marine
Protection, Research and Sanctuaries
Act; the Clean Air Act; or a State permit
where the State program has been
approved as ensuring compliance with
section 405. In addition section 405(e)
prohibits any person from disposing of
sludge from a POTW or other treatment
works treating domestic sewage except
in accordance with the section 405(d)
regulations.
II. Background
Subtitle D of RCRA establishes
framework for Federal, State, and local
government cooperation in controlling
the management of nonhazardous solid
waste. The Federal role in this
arrangement is to establish the overall
regulatory direction, to provide
minimum standards for protecting
human health and the environment, and
to provide technical assistance to States
for planning and developing
environmentally sound waste,
management practices. The actual
planning and "direct implementation of
solid waste programs under Subtitle D,
however, remain State and local
functions.
Section 405(dJ-(f) of the CWA
establishes a comprehensive framework
for regulating the use and disposal of
sewage sludge. Section 405(d) provides
for the Federal promulgation of
numerical limitations and management
practices governing the use and disposal
of sludge. Section 405{e) provides for
Federal enforcement of these standards.
Section 4G5(f) requires the
implementation of these regulations
through permits issued to POTWs under
section 402 of the CWA, unless they
have been included in a permit issued
under Subtitle C of RCRA or other
authority listed in that section. The
permits are to be issued by EPA or by a
State with a program that has been
approved as ensuring compliance with
section 405 of the CWA.
A. Current Subtitle D Criteria
Under the authority of sections
1008(a)(3) and 4004(a) of RCRA, EPA
promulgated the "Criteria for
Classification of Solid Waste Disposal
Facilities and Practices" (40 CFR Part
257) on September 13,1979. EPA issued
minor modifications to these Criteria on
September 23,1981. These Subtitle D
Criteria establish minimum national
performance standards necessary to
ensure that "no reasonable probability
of adverse effects on health or the
environment" will result from solid
waste disposal facilities or practices. A
facility or practice that meets the
Criteria is classified as a "sanitary
landfill"; a facility failing to satisfy any
of the Criteria is considered an "open
dump" for purposes of State solid waste
management planning. State plans
developed under the "Guidelines for
Development and Implementation of
State Solid Waste Management Plans"
(40 CFR Part 256) must provide for
closing or upgrading all existing "open
dumps" within the State.
The existing Part 257 Criteria include
general environmental performance
standards addressing eight major topics:
Floodplains (§ 257.3-1), endangered
species (§ 257.3-2), surface water
(§ 257.3-3), ground water (§ 257.3-4),
land application (§ 257.3-5), disease
(§ 257.3-6), air (§ 257.3-7), and safety
(257.3-8). The following briefly
summarizes these provisions.
- Section 257.3-1 specifies that facilities
or practices in floodplains shall not
interfere with the floodplain or result in
washout of solid waste so as to pose a
hazard to human life, wildlife, or land or
water resources. Section 257.3-2
prohibits solid waste disposal facilities
and practices that cause or contribute to
the taking of any endangered or
threatened species or result in the
destruction or adverse modification of
the critical habitats of such species. The
surface water provision, § 257.3-3,
specifies that disposal facilities shall not
cause a discharge of pollutants or
dredged or fill material to waters of the
United States that is in violation of
section 402 or 404 of the CWA. Section
257.3-4 lays out the ground-water
protection standards, which require that
facilities and practices not exceed the
Safe Drinking Water Act maximum
contaminant levels (MCLs) in an
underground drinking water source
beyond the solid waste unit boundary or
beyond an alternative boundary
specified by the State.
Section 257.3-5 requires that a facility
or practice meet certain restrictions with
respect to the concentrations of
cadmium and polychlorinated biphenyls
(PCBs) contained in waste applied to
land used for producing food chain
crops. Section 257.3-6 specifies'that
waste disposal facilities and practices
must institute appropriate disease
vector controls, such as periodic
application of cover material. In
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33317?
addition, § 257.3-6 requires pathogen
reduction processes for sewage sludges
and septic tank pumpings applied to
•land.
The air criterion in § 257.3-7 prohibits
open burning of solid waste (with
certain exceptions) and specifies that •
the applicable requirements of the State
Implementation Plans developed under
section 110 of the Clean Air Act must be,
met. Finally, the safety provisions of •-
% 257.3-8 require control of explosive
gases, fires, bird hazards to aircraft, and
public access to the facility.
Currently, EPA does not have the
authority to enforce these existing Part
257 Criteria directly, except in situations
involving the disposal or handling of .
POTW sludge. Federal enforcement of
POTW sludge handling facilities is
authorized under the CWA. The existing
Criteria, as they apply to non-sludge-
handling facilities, are enforced by the
States through State regulatory
programs or.by citizens through the
citizen suit provisions of section 7002 of
RCRA. ,
B. Hazardous and Solid Waste
Amendments of 1984
In 1984, Congress made significant
modifications to Subtitle D of RCRA
through the Hazardous and Solid Waste'.
Amendments. As described below, the
major modifications to Subtitle D
include requirements that EPA complete
a Subtitle D study and revise the Part '.
257 Criteria, and that States implement
revised permitting programs.
1. Subtitle D Study and Report to
Congress
HSWA added a new section 4010 to
RCRA, which requires EPA to "conduct
a study of the extent to which the
guidelines and Criteria under this Act
(other than guidelines and Criteria for
facilities to which Subtitle C applies)
which are applicable to solid waste
management and disposal facilities
* * * are adequate to protect human
health and the environment from ground
water contamination." This study is to
include a detailed assessment of the
adequacy of the Criteria regarding
monitoring, prevention of
contamination, and remedial action for
protecting ground water and also is to
identify "recommendation with respect
to any additional enforcement
authorities which the Administrator, in
consultation with the Attorney General,
deems necessary." EPA anticipates
submitting a Report to Congress on the
results of the study shortly.
2. Criteria Revisions
Section 4010 also required EPA to
revise the Subtitle D Criteria by March
31.1988, for facilities that may receive
household hazardous waste or",-.
hazardous waste from small quantity
generators. These revisions must be
those necessary to protect human health
and the environment, but, at a minimum,
should require ground-water monitoring
as necessary to detect contamination,
establish location standards for new or
•' existing facilities, and provide for
- corrective action, as appropriate. ,
Section 4010 further states that EPA may
take into account the "practicable
capability" of facilities to implement the
Criteria. Today's proposal represents
the first phase of the Agency's
promulgation of these mandated
revisions.
3. Implementation and Enforcement
HSWA amended section 4005 of
RCRA to require States to establish by
November 8,1987, a permit program or
other system of prior approval to ensure
that facilities that receive HHW or SQG
hazardous waste are hi .compliance with
the existing Part 257 Criteria. Within 18
months of promulgation of revised -.'
'_ Criteria, each State must modify its
permit program to ensure compliance
with the revised Criteria. If the
Administrator determines that a State
has not adopted an adequate permit
program, EPA may enforce the revised
Criteria at facilities that may receive
HHW or SQG waste.
C. Current Sewage Sludge Criteria
The existing Part 257 Criteria
discussed above were co-promulgated
under the joint authority of RCRA and
section 405(d) of the CWA. The Part 257
regulations thus apply to all sludge land
disposal practices, except distributing
and marketing sludge. Because these
regulations apply to sewage sludge, they
are directly enforceable by EPAlagainst
any person found to be in violation of
them.
In February 1987, Congress enacted
the Water Quality Act of 1987, which
amended portions of the CWA,
including section 405. First, Congress
expanded section 405(d) to impose new
; standard-setting requirements with
associated deadlines. Second, Congress
established new sludge permitting
requirements in section 405(f) along with
State program requirements. EPA
currently is developing sludge - .
regulations to be proposed under section
405(d) and published in 40 CFRPart 503.
In addition, EPA already has published
a proposed regulation in 40 CFR Part 501
that would implement the requirements
of section 405(f) (53 FK 7642, March 9,
1988). The comment period for thsse
latter regulations closed on May 9,1888.
The Part 503 regulations, when
promulgated, will address the '.'-•""
• incineration; ocean disposal; land
application, and distribution and •
marketing of sludge. Lastly, .and most
relevant here, they also will regulate
sludge mbmofills, which are landfills in
which only sewage sludge is disposed of
(Lei, no other type of solid waste is co-
disposed oiF with the sewage shidge).r .'.-''•
' Those regulations will not, however, ;
contain regulations for the co-disposal
• of sewage sludge with household
wastes. Regulations for the co-disposal
of sewage Kludge arid household wastes,
rather, are part of today's proposal. 13y
this action, the Agency seeks to achieve
consistency in its regulation under two
legal authorities of a single disposal ,
practice—the co-disposed of sewage ;
sludge and other solid wastes hi
municipal stolid waste landfills.
HI. Nature ,and Scope of the Problem •
To fulfill its responsibilities under
HSWA, EPA has conducted a series of
studies and! analyses of solid waste
characteristics, waste disposal •
practices, and environmental and public
health impacts resulting from solid
waste disposal. Preliminary results of
these studios were summarized in the
"Subtitle D Study Phase I Report," '
issued in October 1986 (Ref. 34). Final
results, whlich form the basis for Agency
decision making for this rule, are
incorporated in EPA's Subtitle D report,
to Congress, which is expected to be
issued shortly. The key studies pertinent
to today's proposal are summarized
below. Copies of the reports mentioned
below are available for public review in
the docket ifor this rulemaking. , -
A. EPA Studies of Solid Waste
Management
1. Analysis of Solid Waste ,
Characteristics
To analyze the characteristics of solid
waste, EPA conducted numerous studies
to determine the volume, characteristics,
and management methods of wastes
regulated under Subtitle D. These
studies revealed that more than 11 .
billion tons of solid waste are generated
each year, including 7.6 billion tons of
industrial nbnhazardous waste (which
includes about 55.8 million tons of ;
electric utility wastes), 2 to 3 billion .tons
of oil and gas waste (including both
drilling wastes and produced wastes),
more than 1.4 billion tons of mining
waste, and nearly 160 million tons of
municipal solid waste.
Several Subtitle D wastes currently .
are being addressed under separate
Agency efforts and thus were not.
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
examined in detail in EPA's Subtitle D
study. In particular oil and gas wastes,
utility wastes, and mining waste have
been the subject of special-studies
conducted under section 8002 of RCRA
and are being considered separately for
rulemaking. In addition, the Agency
currently Is closely evaluating, in a
separate effort, the characteristics and
management practices for municipal
waste combustion ash. Thus, the
following discussion focuses on the
characteristics of municipal solid waste,
household hazardous waste, and small
quantity generator hazardous waste,
which are the primary waste streams
addressed by today's proposal, as well
as industrial solid waste.
In 1986, EPA sponsored a study
entitled "Characterization of Municipal
Solid Waste in the United States, 1960 to
2000" (Ref. 16). This study examined the
quantity and composition of municipal
solid wastes and forecast the
characteristics of municipal solid wastes
in the U.S. through the end of the
century. The study found that, on
average, more than 50 percent of
municipal solid waste comprises paper,
paperboard, and yard wastes; nearly 40
percent is metals, food wastes, and
plastics; and the remaining 10 percent is
wood, rubber, leather, textiles, and
miscellaneous inorganics. Waste
composition was found to be highly site-
dependent and influenced significantly
by climate, season, and socioeconomic
factors. The study determined that
approximately 150 million tons of
municipal solid waste were generated in
1984 (of which more than 126 million
tons were landfilled) and that the waste
volume was expected to increase
significantly by the end of the century.
EPA recently completed an update to
this study entitled, "Characterization of
Municipal Solid Waste in the United
States, 1960-2000 (Update 1988)" (Ref.
17). This update estimated that 158
million tons of municipal solid waste
were generated in 1986.
In October 1986, EPA published "A
Survey of Household Hazardous Wastes
and Related Collection Programs,"
which analyzed the existing information
on characteristics of HHW and
reviewed HHW collection programs
(Ref. 30). This study indicated that
common discarded household products,
such as household cleaners, automotive
products, paint thinners, and pesticides,
may contain hazardous wastes that are
either listed under Subtitle C or exhibit
one or more hazardous characteristics.
Household wastes, including HHW,
currently are exempt from regulation
under Subtitle C of RCRA
A third study, "Summary of Data on,
Industrial Nbnhazardous Waste
Disposal Practices," compiled available
data on industrial solid waste
characteristics and land disposal
practices in 22 major manufacturing
industries (Ref. 29). This study estimated
that roughly 390 million metric tons of
industrial nonhazardous waste are
generated by these industries each year,
that 35 percent of these wastes are
managed on site, and that 75 percent of
these wastes are generated by four
industries: Iron and steel, electric power
generation, industrial inorganic
chemicals, and plastics and resins.
Additional information on industrial
nonhazardous waste quantities was
provided by the Industrial Facility
Screening Survey (Ref. 35), which
estimated that approximately 7.6 billion
tons of industrial nonhazardous wastes
are generated each year. The survey is
described in more detail below.
In 1985, EPA also conducted the
"National Small Quantity Generator
Survey," which characterized SQG
waste volumes and disposal practices
(Ref. 14). (For purposes of this study,
SQGs were defined as those operations
yielding less than 1,000 kilograms of
hazardous waste per month.) This
survey indicated that SQGs annually
produce 940,000 metric tons of
hazardous waste, consisting largely of
lead-acid batteries, solvents, and
strongly acidic or alkaline wastes.
Furthermore, the survey found that solid
waste disposal facilities, including
MSWLFs, are the second most frequent
destination for SQG hazardous waste
shipped off site. EPA estimates that
MSWLFs may receive from 5 percent to
16 percent of the SQG hazardous 'waste
produced.
Existing information on MSWLF
leachate, summarized in the background
document on MSWLF leachate quality
(Ref. 8), indicates that leachate from
MSWLFs generally contain a wide range
of inorganic and organic hazardous
constituents in varying concentrations.
Landfill gas comprises 50 to 60 percent
methane, 40 to 50 percent carbon
dioxide, and less than 1 percent
hydrogen, oxygen, nitrogen, and other
trace gases.
2. Review of Waste Disposal Practices
EPA conducted numerous studies to
gather existing information on the
numbers of Subtitle D facilities, facility
design and operating characteristics,
leachate and gas characteristics, and
environmental and human health
impacts associated with different types
of facilities. EPA relied on several key
sources of information on the number
and design and operating characteristics
of Subtitle D facilities for this proposal.
The first major source was. an, EPA mail
survey of State solid waste management
programs conducted in 1985 to gather
information on State Subtitle D
programs and facilities. The final report
on the survey, "Census of Stats and
Territorial Subtitle D Nonhazardous
Waste Programs" (State Census), was
issued in 1986 (Ref. 46).
The State Census indicated that there
are about 227,000 Subtitle D disposal
facilities, excluding waste piles (which
were not included in the survey). This
total includes approximately 16,500
landfills, 191,500 surface impoundments,
and 19,000 land application units. In
addition, the State Census indicated that
there are more than 145,000 oil and gas
waste or mining waste facilities, which
EPA is addressing in separate efforts.
The States estimated that roughly
37,000 Subtitle D facilities (or 16 percent
of all the facilities) may receive •
hazardous wastes from households or
from small quantity generators. The
States' estimate of 16,500 landfills
included approximately 9,300 MSWLFs;
however, the States subsequently
identified errors in the numbers reported
for MSWLFs and submitted revised
figures. These revised State figures, and
the results from EPA's 1986 municipal
solid waste landfill survey, which was a
random sample of approximately 1,250
MSWLFs nationwide, indicate that there
are a total of 6,034 MSWLFs (as of 1986).
The MSWLF survey also provided
detailed information on MSWLF design
and operation.
In developing this rule, EPA also
utilized the results of an industrial
facility screening survey, which
involved a telephone screening of nearly
30,000 establishments in 22 industries.
The primary purpose of this screening
survey was to provide EPA with basic
information on the universe and
characteristics of industrial solid waste
disposal facilities.
In general, information on Subtitle D
disposal facilities is limited, except for
MSWLFs. While new MSWLFs are
expected to be better located, designed,
and operated, the following
observations can be made regarding the
universe of existing MSWLFs.
According to the State Census, MSWLFs
are distributed throughout the country,
occurring in virtually every
hydrogeologic setting, and generally
concentrated near more populated
areas; they are owned predominantly by
local governments (80 percent), with the
remainder owned by private entities (15
percent), the Federal Government (4
percent), and State governments (1
percent). Approximately 42 percent are
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33319
small (less than 10 acres) and 52 percent
- dispose of small amounts of waste (less
" than 17.5 tons per day); only 15 percent
are designed with liners (natural or
synthetic) and only 5 percent have
leachate Collection systems. Current
data also indicate that only 25 to 30
percent of MSWLFs have some type of
ground-water monitoring system.
Results from the 1986 MSWLF survey
generally are consistent with these
results.
3. Assessment of Impacts
Impacts associated with MSWLFs and
industrial Subtitle D facilities are
described below. Existing data indicate '
, that some MSWLFs are adversely
affecting the environment and could
harm human health. Industrial solid
waste facilities need to be examined
more closely to determine their impacts.
a. Municipal Solid Waste Landfills.
State inspection data, case study
. evidence, risk characterization studies,
waste and leachate characteristics, and
the current limited use of design controls
indicate that some MSWLFs have
degraded the environment and that this
degradation could continue. Older
landfills are of most concern because
they may have received large volumes
of hazardous waste and, in general, their
/.use of design controls was very limited;
however, existing data are not sufficient
to conclusively demonstrate that:
MSWLFs currently are harming human
health, other than data indicating acute
impacts associated with methane
releases. Current human health impacts
from past exposure to contaminant
releases from MSWLFs are difficult to
isolate due to the complex interaction of
factors that affect human health.
However, the Agency's recently >
completed risk assessme'nts indicate
that MSWLFs present future potential
risks to human health.
More than 500 MSWLFs, or about 25
percent of MSWLFs with ground-water
monitoring systems, were reported by
States to be violating a State ground-
water protection standard, although the
nature and extent of these violations are
unknown. In some States, any
detectable degradation of the ground
water is considered a violation. Most
facilities do not monitor for organic
hazardous constituents in ground water,
so these violations represent analyses
for a limited set of pollutants. States
also reported that 845 MSWLFs were
cited for air-related violations (many of
which are likely to be odor-related
incidents), and 660 MSWLFs were cited
for surface water contamination. Some
of these violations may have been
reported at sites established before
existing State and Federal regulations
wereinplace,
EPA has summarized case study
information documenting ground-water
and surface water contamination
incidents (Ref. 7).. Evaluationof 163.
MSWLF case studies revealed ground-
water contamination at 146 facilities
and surface water contamination at 73
facilities. For most of these landfills, ,-
information on the waste received either
was not available or was incomplete,
although a limited number are known to
have received hazardous waste before
the Subtitle C regulations were issued.
At about 50% of the facilities with
ground-water contamination, specific
contaminants were identified. The most
common constituents were iron,
chloride, manganese, trichlorqethylene,
benzene, and toluene. At several sites,
drinking water sources were
contaminated. Ground-water '
contaminant plumes characterized at
three of the sites extended to (or nearly
to) the base of an aquifer at depths of :
approximately 70 feet (at two sites) and
300 feet (at one site).
The plume from one site migrated one-
half mile downgradient of the landfill,
while the plume at another site migrated
almost one and one-half miles
downgradient.
Typically, those facilities causing
ground-water contamination were more
than 10 years older than facilities
reporting no impacts. Ground-water
impacts appeared to be more severe in
locations characterized by high net :
- infiltration rates and high ground-water
flow rates. Most facilities that had
contaminated ground water were
located close to the ground-water table,
underlain by highly permeable soils, or
had no or very limited engineering
controls. The case study information
identifies several factors that may be
related to failure at a particular facility,
specifically the landfill's age, location, •
and engineering design; however, it is
unknown whether this sample is
representative of the universe of
MSWLFs, and it is not possible to
isolate the specific factors responsible
for each failure.
Analysis of damage cases involving
methane indicates that methane must be
controlled to protect human health.
Methane is produced in MSWLFs
through anaerobic decomposition of
organic waste and is explosive at ;
sufficiently high concentrations (the ,
lower explosive limit). Existing Federal
regulations require that the
qoncentration of explosive gases should
not exceed 25 percent of the lower
explosive limit in facility structures and
should not exceed the lower explosive
limit at the facility boundary. Methane
is produced in such abundance that
methane collection projects are in place
at approximately 100 landfills for the :
primary purpose of resource recovery
and energy production. Where methane
is hot controlled, fires and explosions
have occurred. In 23 of 29 damage cases
studied, methane has been measured in
concentrations above the lower
explosiveiliimit at distances up to 1,000. ,
feet off site. Explosions and fires, both -•
on site and off,site, have occurred in 20
of the 29 cases, loss of life has been
documented in five instances, and J • '•;
injuries have been reported in several
others. Most of these; sites where
injuries or death occurred did not: have a
landfill gaslcontrol system., ..,..'•
EPA also examined the characteristics
of landfills on the Superfund National
Priorities list (NPL) in May 1986 (Ref.
26). Of the 1350 sites listed or proposed,
for listing oh the NPL (in May 1986), 184
sites (22 percent) were identified as
MSWLFs. In addition, of the 27,000 sites
. in the Superfund data base, almost one
fourth are MSWLFs. In general, the +
MSWLFs on the NPL were poorly
located and! designed. Because most of
the NPL sites were in operation before
1980 (the effective date of EPA's
hazardous waste rules) and may have
received hazardous wastes in addition
to Subtitle D wastes,>they are not
representative of hewer, better designed
and operatesd MSWLFs; however, these ,
sites indicate the extent to which older
and poorly located, designed, and ,
managed landfills can harm the .
environment. Current data indicate that
70 percent of existing MSWLFs were in
operation prior to 1980.
The,State data, case study -
information, and NPL study were
supplemented by a risk assessment of
-MSWLFs (Ref. 10). The risk assessment
was completed using the Subtitle D Risk
Model, which was developed to
evaluate the risks and resource damage
associated with grpund:water
contamination at MSWLFs and to
identify the factors that affect the
nature, extent, and severity of
environmental impacts from these
facilities. The model simulates pollutant
release, fate, and transport; exposure;
impacts; and corrective action. The / -
model is described in more detail in ,
Section XI of this preamble.
Caveats to the risk and resource
damage analysis results presented in the
risk assessment need to be recognized.
First, the risk and resource damage
modeling includes considerable
uncertainty. The model components that
introduce the most uncertainty are those '
that predict leachate quality for trace.
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33320
Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
organics, the probability and
consequences of containment system
failure, and the human health risk
resulting from exposure to toxic
substances [e.g., the dose-response
models). Second, the model estimates
effects from new landfills, but does not
analyze the risk and resource damage
impacts from existing facilities.
The risk analysis estimates the human
health risk for the maximum exposed
Individual (i.e., the mean of the average
lifetime risk over the 300-year modeling
period of the facility) and the total
population using ground water as a
drinking water source within one mile of
the faculty. Current data indicate that 54
percent of existing MSWLFs have no
downgradient drinking water wells
within one mile, a finding that strongly
influences model results because current
data and model limitations do not allow
the risk to be estimated at facilities with
drinking water wells beyond one mile.
Thus, under this model, such facilities
are considered to pose no risk.
Using the well distribution indicated
by the MSWLF survey (i.e., no drinking
water wells located within one mile of
54 percent of the landfills), the risk
model estimates that, in the baseline,
fewer than 1 percent of MSWLFs pose
risk greater than 1X10-4 (i.e., an
exposed individual would have a greater
than one in ten thousand chance of
contracting cancer in his or her lifetime
as a result of the exposure), 5.5 percent
pose risk in the IXlO-s to 1X10-4 range,
and 11.6 percent pose risk in the IXlO-a
to IXlO-s range. Overall, approximately
17 percent of MSWLFs pose risks
greater than 110 X-«. Out of the eight
leachate constituents modeled, the three
principal constituents contributing to
human health risk are vinyl chloride,
1,1,2,2-tetrachloroethane, and
dichloromethane.
For landfills located within one mile
of a drinking water well (48 percent of
all landfills), 14 percent pose risk
exceeding IXlO-s, and nearly 40
percent pose risk greater than IxlO-a. If
future wells are located near existing
MSWLFs (or new sites are located near
current wells), the overall risk
distribution may be closer to the
estimates for this subgroup. The overall
risk distribution changes significantly if
it is assumed that all drinking water
wells are located at the facility
boundary (assumed to be 10 meters from
the landfill unit). Using this conservative
scenario, it is estimated that
approximately 35 percent would pose
risk greater than IXlO-s, and about 67
percent of MSWLFs would pose risk
exceeding IXlO-a.
Because risk is the result of a complex
interaction among many factors (some
of which have not been accounted for in '
this analysis), no single factor is
responsible for most of the variation.
Thus, in addition to well distance, the
results of the analysis identified other
risk-contributing factors, which include
infiltration rate, facility size, and aquifer
characteristics. These factors are similar
to those identified in the case studies
discussed above. More detailed
discussion of EPA's risk assessment is
provided later in this preamble.
b. Sewage Sludge Disposal in
MSWLFs. EPA estimates that
approximately 6,800 POTWs dispose of
their sludge in MSWLFs. This represents
the sludge disposal practice used by 44
percent of all POTWs. The total volume
of co-disposed sewage sludge is slightly
under 3 million tons per year, which is
approximately 40 percent of the volume
generated annually by POTWs.
EPA has not performed a separate risk
assessment addressing the sludge
component of municipal solid waste
landfills. Sludge typically is a small
component of the landfill (i.e., 5
percent). It is not technically feasible to
monitor separately the fate and
transport of the sludge and its
constituents from the fate and transport
of other wastes in the landfill arid their
constituents. Moreover, while there has
been some research on the interaction of
sludge and other wastes in a co-disposal
situation, there are as yet no definitive
results from such work. Therefore, the
discussion above on the practices and
risks associated with MSWLFs
constitutes the best current information
on those landfills that receive sludge
together with the other wastes.
c. Industrial Subtitle D Facilities. In
1985, about 28,000 industrial solid waste
land disposal facilities handled
approximately 7.6 billion tons'of waste.
Although few data on specific health
and environmental impacts of these
facilities are available, the large volume
of waste and number of facilities
present concerns about actual and
potential threats from these facilities.
More than half of these facilities are
surface impoundments, which create
concerns because of the mobility and
physical driving force of liquids in
impoundments and the current limited
use of design controls. Current data are
insufficient,, however, to determine the
extent of potential problems.
Study results indicate only sporadic
use of design and operating controls at
industrial solid waste landfills and
surface impoundments, with only 12
percent and 22 percent, respectively,
'employing any type of liner system.
Study findings also revealed that few of
these facilities have monitoring systems
and only 35 percent were inspected by
States in 1984, the'latest year for which
data are available.
Limited data on violations of State
requirements, coupled with these
statistics on design and operating
controls, suggest that releases may be
occurring, but more data are needed to
determine the impacts of industrial
'Subtitle D facilities. The notification and
exposure information requirements in
Part 257 proposed today are a first step
toward gathering this information.
B. State Controls on Solid Waste
Management
Through the State Census, EPA
gathered information on State Subtitle D
programs in areas such as organization
and resources, regulations and permit
programs, and enforcement. In addition,
EPA completed a detailed review of
State regulations in 1984 (Ref. 25) and a
supplemental review in 1987 (Ref. 9).
The following is a brief overview of
State solid waste regulatory programs.
MSWLFs are the Subtitle D facilities
most closely regulated by the States.
Most States and Territories impose
some set of overall facility performance
standards; however, among the States
and Territories, specific design and
operating standards vary greatly. For
example, the 1987 regulatory review
determined that 24 States and
Territories require liners and 27 States
and Territories require leachate
collection systems. As of 1984, 28 States
and Territories required gas control
systems, and 38 specified some sort of
run-on/run-off controls. Nearly all allow
- case-by-case exemptions and variances.
Many States and Territories impose
some location standards or restrictions
on MSWLFs. These usually include
floodplaih siting restrictions, which
range from prohibitions on siting in the
100-year floodplain to specific design or
performance standards for operations
within the floodplain to a general
directive to avoid sites subject to
flooding. Although minimum distances
from surface and ground waters and
from airports and utility lines sometimes
are specified, they too vary widely. For
example, prescribed distances from
habitable residences vary from 200 feet
to three-quarters of a mile and required'
distances" from community water
supplies range from 400 feet to one mile.
Thirty-eight States and Territories
specifically require ground-water
monitoring systems, and an additional
12 States have general authority to
impose ground-water monitoring on a
site-specific basis. With regard to
corrective action, 21 States have
requirements in their regulations, while
22 others have general authority to
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Federal Register J
August 30, 1988 / iP]?oposed Rules
33321
impose corrective action. Approximately
half of the States and Territories .require
• methane gas monitoring and/or surface
water monitoring. While most States
arid Territories have general guidelines
or requirements for facility closure and
post-closure maintenance requirements,
these requirements vafyTvidely in
stringency. Finally, some form of
financial assurance for closure and post-
tjlosure care is required in about half of
the States and Territories.
As can be seen from the above
information, there are certain gaps in
some State and Territorial regulatory
programs, which may result in
Inadequate protection of human health
. and the environment in some parts of
the country. In some cases, rthe gaps in
State and-Territorial programs may be -
linked both to the inadequate .
implementation of the existing Federal
Criteria by certain States and Territories
and to the absence of certain key
regulatory provisions in the current
Federal Subtitle B Criteria themselves.
For example, the current Criteria do not
require ground-water monitoring or
monitoring for methane releases, sp
MSWLF owners and operators may
choose not to install monitoring devices
(if the State or Territory does not
specifically require them) and thus may
not detect problems before significant
problems have occurred. The existing
Criteria also do not require corrective
measures in the event contamination
above levels of concern occurs.
Furthermore, MSWLF owners and ,
operators are not .required to provide
continued protection of human health
and the environment through effective
closure procedures and post-closure
care. Agency experience since 1979 in
both fee hazardous waste regulatory '
program and response actions under
:Superfuricl has confirmed the importance
of such preventive measures for long-
termprotection of human health and the
environment, -.-••',
!C. Need for Revisions to the Part 257
Criteria
The evidence briefly described above
indicates that MSWLFs, when
improperly designed and operated, may
present threats to human health and the
environment The evidence further
indicates/that the Federal Criteria are
missing several key regulatory
provisions. These provisions include
location restrictions, ground-water
monitoring, and corrective action, which
all are mandated TsyHSWA. In addition,
'current data point to the need for the
addition of methane monitoring, closure
and post-closure care, and financial
assurance requirements. The Agency
believes that the available data clearly
indicate that the current Federal Criteria
have not proved adequate to protect
human health and the environment and
must be revised to ensure such
protection.
These revisions to the Subtitle D
Criteria come at a time when heightened
concern is directed at issues of solid
waste management. This concern
derives from State, Territorial, and local
government difficulties to ensuring
adequate capability for municipal solid
waste management as well as public
concern regarding potential hazards
presented by waste disposal facilities.
EPA is aware of the crisis in solid waste
management and believes that these
proposed Criteria revisions should be a
major step toward alleviating public
concern with respect to inadequate
controls on solid waste disposal. In
addition, EPA oelieves these proposed
revisions provide States and Territories
with the flexibility needed to address
the practicable capacity of the regulated
community.
TV, Public Participation in This
Rulemaking
Given the number and diversity of
MSWLFs and the potentially significant
impacts that the revised Criteria may
have on them, EPA involved the public
and private sector in the rulemaking
process. This effortincludedpublic
meetings and outreach activities aimed
at encouraging participation in the
process. ,
Since the spring of 1985, EPA has
hosted or participated in a series of
public meetings, workshops,
conferences, and other activities
focusing on issues in the Subtitle D
program. In August 1985, EPA sponsored
a conference explaining the major
provisions of the Hazardous and Solid
Waste Amendments of 1984 that
affectedthree Icey-RCRA programs—
Subtitle D, small quantity generators,
and underground storage tanks. During
the conference, EPA held workshops on
the following Subtitle D issues: 1)
Identification of available information
and case studies, 2) .ground-water
monitoring and protection requirements,
3) closure and post-closure care and
financial responsibility requirements, 4}
waste restrictions and liquids
management requirements, and 5J liner
and location requirements. The
workshops provided a forum for EPA
and the participating State and local
governments, public interest groups,
industry, and trade associations to
exchange information and discuss
significant regulatory issues.
On June 27; 1986, EPA hosted a public
meeting in Washington, DC, on the
issues and options being considered for
the revisions lo the Subtitle D Criteria.
At that time, EPA presented the
Agency'!s initial thinking on therevised
Criteria, solicited comments, and -. :
responded to questions from "'-.•"
representatives of States, local
governments,public interest groups, and
.private organizations. - ,
On November 18 to 20,1986, EPA held
a three-day conference in Arlington,
Virginia;, on :splid waste disposal
facilities and HHW collection programs.
At this conference, EPA presented
interim results of the Subtitle D Study.
reported on the status of the Subtitle D
Criteria revisions, and discussed issues
associated with HHW collection'
programs. Conference participants also
made presentations on State regulatory
perspectives and public-andprivate-
sector views. .-.-,• . -
EPA silso sponsored a series of policy
discussion meetings ,in 1986 involving
high-level representatives of the
principal interest groups affected by the
Subtitle ID program, including State and
local governments, -citizen and
environmental groups, and industry and
trade associations. The broad objectives
of these meetings, which were
coordinated for EPA by the
Conservation Foundation, were to
examin?! the effectiveness of the Subtitle
D program, identify issues likely to
affect implementation of the revised
Criteria, and suggest innovative
strategies to address problems ;
identified. , :
V. Scopi! and Structure of Today's
Proposal \ . - - - -•"'..'
The reivised Criteria EPA is proposing -
today vsiry considerably in scope and
content from the current Criteria in Part
257. Hhia section explains the basis for
EPA!s decisions with respect to the
*scope aiid structure of today's proposal.
A. Scope of the Existing Part 257
The existing Part 257 Criteria are
applicable to all solid waste disposal
facilities and practices regulated under
Subtitle D of RCRA, With certain
exceptions listed in § 257.1(c), the
Criteria iapplyto all types of facilities
(i.e., landfills, surface impoundments,
land application units, and waste piles)
used for disposal of solid waste, as well
as all types of solid wastes (i.e.,
municipal, industrial, commercial,
agricultural, mining, and oil and gas
waste} regulated under Subtitle D of
HCRA. !
Part 257 also applies to the disposal of
sewage siludges from POTWs, but the
Agency currently is developing specific
standards for managing PQTW sewage
sludge under section 405(d) of the CWA.
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33322 federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
These standards will establish pollutant
concentration limits and management
practices for sludge monofills, land
application units, (including distribution
and marketing), incineration, and ocean
dumping. The Agency plans to propose
these standards in 1989. At that time,
EPA will propose amending Part 257 to
exclude PQTW sewage sludge from its
requirements. As previously discussed,
today's revised Criteria proposal
governs the co-disposal of sewage
sludge with household wastes.
B, Scope of Today's Proposal
HSWA directs EPA to develop
revisions to the Part 257 Criteria for the
subset of solid waste disposal facilities
that "may receive hazardous household
wastes or hazardous wastes from small
quantity generators." Congress thus
identified for EPA the scope of the
revised Criteria. Based on the studies
performed to date, EPA has found that
the HSWA-mandated scope includes all
MSWLFs. which may receive HHW and
SQG hazardous waste, and some
industrial solid waste disposal facilities
and certain other Subtitle D facilities,
which may receive SQG hazardous
waste. However, as noted above, EPA
has obtained extensive information on
only the characteristics of MSWLFs and
the risks they may pose to human health
and the environment Neither EPA nor
the States have comparable information
on industrial solid waste disposal
facilities at this time. For this reason,
EPA has decided to undertake the
revisions to the Part 257 Criteria in
phases.
The first phase will apply to MSWLFs
(landfills that receive household waste)
and is the subject of today's proposal. A
second phase will apply to industrial
solid waste disposal facilities (disposal
facilities that receive solid waste
generated by manufacturing or
industrial processes), including those
that receive SQG hazardous waste, and
will be proposed at such time as EPA
has adequate data on which to base its
decisions. Because of EPA's concern
about industrial solid waste disposal
facilities (including landfills, surface
impoundments, waste piles, and land
application units), however, EPA
already has initiated data collection,
described later in this preamble, to
determine the potential impacts of
certain of these facilities. In addition,
EPA today is talcing the first regulatory
step in addressing industrial facilities by
proposing to require notification and
exposure Information from owners and
operators of certain of these facilities.
The Agency recognizes that additional
regulatory efforts will be necessary to
regulate other disposal facilities not
included in the first two phases.
C. Structure of Today's Proposal
Because today's proposal is
substantially different in scope and
content from the Part 257 Criteria, EPA
has chosen to create a new Part 258 for
the revised Criteria the Agency is
proposing today. EPA considered simply
amending Part 257 to include the revised
Criteria for MSWLFs, but decided
against that option because of the
confusion that might be created by
having Criteria of general applicability
alongside revised Criteria applicable
only to MSWLFs. Placing the revised
Criteria in a separate Part 258 tracks the
distinction made by Congress, which ,
indicated that the revisions only apply
to facilities that may receive HHW or
SQG hazardous waste. It also leaves the
Part 257 Criteria in place for all other
solid waste disposal facilities besides
MSWLFs.
D. Scope and Effect of Today's Proposal
on MSWLFs That Co-dispose of Sludge
The regulations proposed today would
apply, under the authority of section 405
(d) and (e) of the Clean Water Act, to all
MSWLFs that co-dispose of sludge.
Section 405(d) requires EPA to
promulgate regulations providing
guidelines for the use and disposal of
sludge. In general, these regulations
must identify numerical limitations and
management practices that are adequate
to protect public health and the
environment from reasonably
anticipated adverse effects; however, if,
in EPA's judgment, it is not feasible to
prescribe or enforce a numerical
limitation for a pollutant, EPA may
instead promulgate a design, equipment,
management practice, or operational
standard, or combination thereof, that in
EPA's judgment is adequate to protect
public health and the environment from
reasonably anticipated adverse effects.
Today's proposal reflects EPA's
tentative determination that it is not
feasible to prescribe concentrations of
pollutants in co-disposed sludge that are
protective of public health and the
environment. Sludge typically is a minor
portion of a co-disposal MSWLF (e.g., 5
percent). It is not feasible to separately
evaluate the fate, transport, and health
and environmental effects of the sludge
as distinguished from the remaining
majority of wastes in the landfill. Nor
does it make sense to try to regulate this
small portion of a landfill's waste on a
concentration basis, while regulating the
entire landfill on a comprehensive
management basis. EPA has concluded
that today's proposal, which establishes
a variety of management and operation
requirements (including numerical
limitations hi the form pf ground-water
protection standards), will protect
public health and the environment from
reasonably anticipated adverse effects.
A significant effect of the
promulgation of these regulations under
section 405(d) of the CWA would be the
renewed eligibility of certain POTWs to
grant removal credits to their industrial
users under section 307(b) of the CWA.
Section 307(b) requires EPA to
promulgate pretreatment standards for
industrial users of POTWs. Section
307(b) also allows an individual POTW
to relax these standards for its industrial
users by giving them a "removal credit"
reflecting the POTWs removal
capability, provided that the credit will
not prevent the POTW from using or •
disposing of its sludge hi accordance
with section 405(d) of the CWA. EPA
has promulgated removal credit ..
regulations in 40 CFR Part 403. On April
30,1986, the United States Court of
Appeals for the Third Circuit
invalidated the version of the removal
credits regulations promulgated hi 1984.
[Natural Resources Defense Council v.
EPA, 790 F.2d 289 (3d Cir. 1986).) EPA
has amended the regulations to respond
to all but one of the Third Circuit's four
holdings (52 FR 42434, November 5,
1987).
The Third Circuit's fourth holding was
that EPA may not authorize POTWs to
grant removal credits to then- industrial
users until EPA promulgates the sludge
regulations required by section 405(d) of
the CWA. EPA considers the regulations
proposed today to respond adequately
to the Third Circuit's decision with
respect to POTWs that dispose of all
then1 sewage sludge through co-disposal
hi MSWLFs. These regulations would
comprehensively regulate this sludge
disposal practice; no further regulation
of this practice is required by law or
contemplated by the Agency. Thus, upon
promulgation of today's regulations, the
POTWs that dispose of all their sludge
in co-disposal MSWLFs may apply to
EPA for removal credits authority, and
EPA may grant such authority to any
POTW mat complies with the
procedural and substantive
.requirements of the removal credits
regulations.
VI. General Approach to Today's
Proposal
EPA's primary goals in developing
today's proposal were to develop
standards that are protective of human
health and the environment, that are
within the practicable capability of the
regulated community, and that provide
, State flexibility hi implementation. In
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33323
order to meet these goals, EPA
considered four options for the approach
'to today's proposal. First, EPA
considered-uniform design and
operating standards for application to
all MSWLFs. Second, EPA considered a
performance standards approach that
defines goals for the design and
operation of MSWLFs. The third and
fourth options are methodology-based
decision frameworks for determining
design and operating requirements* In
the third option, facility requirements
are specified for facilities in various
location categories. The fourth, option
utilizes a risk assessment algorithm to
delineate the necessary design and
operating controls. These options are
not necessarily mutually exclusive;
given .that this proposal contains many
facets, different options >could be
employed for different parts of the mile
[e.g., performance standards for location
requirements and a methodological
approach to design requirements}.
However, in general, EPA chose the
performance standards approach for ,
today's proposal.
The uniform national design and :
operating standards option would
impose specific design .standards and
operating requirements on all units
regardless of location and other relevant
factors. The Agency believes that such
an approach would not adequately
account for variability across the
country. For instance, tiiis approach :
would require EPAjto assume that all
facility locations are ""poor" and impose
comprehensive design standards on all
facilities based on what isnecessary to
protect human health and the
environment in the "poorest" of
locations, A rule that does not take into
> account site-specific location
characteristics would likely over-
regulate MSWLFs in "good" locations;
however, a-uniform standards approach
may be easier to implement and enforce
by States because of the specificity of
the standard. ,
The Agency also considered adopting
the uniform national standards option
with variances, in order to account for
site-specific characteristics. Under this
option, variances would be granted if
the owner or operator could
demonstrate that equivalent protection
is provided by site-specific location,
design, and operating characteristics.
This approach parallels the one adopted
for hazardous waste facilities under
Subtitle C ofRCRA, which imposes
virtually identical requirements (e.g.,
double liners and leachate collection
systems) at all new hazardous waste
landfills. Variances are: then allowed,
.under Subtitle C, based on an adequate
demonstration by the owner or operator
that the specific standard is not
necessary. While variances add some
flexibility, EPA has two concerns about
this approach. First, variance
demonstrations often require substantial
resources on the part of the owner and
operator and the States. Second, EPA is
concerned that public pressure would
limit State or local flexibility in granting
variances/even though they may be
warranted for a specific site. While this
option might provide a high assurance of
protection of .human health and the
environment, it could over-regulate :
some facilities by requiring unnecessary
controls. In addition, this approach does
not fully take into account the
practicable capability of the regulated
community.
The; second approach considered was
to impose overall performance
standards for each facility requirement
These performance goals or standards
would require siteTSpecific analyses to
determine appropriate controls. EPA
chose this approach for this rulemaking
because it allows the greatest flexibility
for the State to consider numerous
location-specific factors in tailoring
facility requirements. In addition,
performance standards are less
disruptive of existing State programs
and give facilities some needed latitude
to meet requirements within the bounds
of their practicable capability. Finally, a
performance standard, as opposed to a
strict design standard, allows for the
consideration of innovative technologies
that may be developed in the future.
The third approach, a methodological
one, was to impose a decision
framework based on location categories
to determine the applicable
requirements for a specific iacility. This
approach would categorize all locations
on the basis of certain characteristics,
then set individual requirements for
each category. Under this approach, ':
appropriate requirements could be
matched.to specific categories of
locations. Methods of establishing
location categories and their
corresponding requirements would oe
specified in the revised Criteria; then
States, using information submitted by
the owner or operator, could determine
the category and apply the associated
requirements to a given facility. A key
advantage to the categorical rule
approach is that it establishes uniform ."•
criteria for matching requirements to
potential problems. For example,
facilities in areas of the country
characterized by abundant rainfall
could be required to collect generated
leachate. Conversely, facilities in the
more arid areas of the country do not
necess&rily generate leachate in
. quantifies sufficient to warrant leachate
control systems, and could be regulated „
accordingly. /
The Agency believes this categorical
requirements approach would provide
protection without over-regulation;
however, a complex, sophisticated • •
scheme would be necessary to address
every location consideration and to
match appropriate requirements.
Furtheimore, it would be difficult to
develop a technically defensible
approach for all requirements for
MSWLFs, particularly those
requirements that necessitate site-
specific analyses ,{e.g., ground-water ;
monitoring). In addition, this .approach
would irestrict .State flexibility because it
would specify which rdesigns are
necessary for each location.
The fourth option, also a
methodlological approach, is based on a
risk assessment algorithm. This
approach would require the Use of a
predictive equation to determine the
necessary facility requirements. The
predictive equation would include some
simplifij/ing assumptions, but would
utilize Hite-specific values for some of
the parameters. Like the categorical'
approach, this option has the -
advantages of employing a uniform
national standards approach that could
be easy to implement; however, it would
be difficult to develop a technically
sound risk algorithm and could restrict
Stateflexibility, ,
EPA ilntends to provide guidance on
how to design MSWLFs to meet the
proposed performance standards. The
agency believes the categorical
approach is one viable method for
determining landfill design, and is
considering-developing this inethodas .
guidance along with the risk algorithm
method. -Both of these approaches to
design requirements are discussedin
more detail dn section IX.D of this
preamble. The Agency requests
comments on the approach proposed
today and on the alternatives presented.
VIL Major Issues
A. Ground-Water Resource Value
Resotirce value jefers to the current
and future importance of .ground water, :
as a wa ter supply and as an ecological
resource. Highly saline ground water or
ground water with very low yield may
have a low resource Value. Pristine "
ground water or ground water in high
demand that cannot easily be jreplaced-
or restored similarly may liave a high
resource value; As EPA was developing
the framework for the revised Criteria,
the Agency considered'at length the
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33324' Fedfcral Register / Vol. 53i No. 168, Tuesday, August 30, 1988 / Proposed Rules
subject of differential protection of
ground water based on its resource
value. Specifically, EPA considered
applying different engineering controls,
monitoring, and corrective action
requirements according to the resource
value of the ground water.
In 1084 EPA issued the Ground-water
Protection Strategy, which established
the concept of differential protection of
ground water depending on its resource
value. Accordingly, three classes of
ground water were identified. Class I
ground waters are defined as special
ground waters that are highly vulnerable
to contamination and that are either
irreplaceable sources of drinking water
or are ecologically vital. Class II ground
waters are defined as current and
potential sources of drinking water and
those having other beneficial uses. Class
II! ground waters are defined as heavily
saline ground water or ground water
otherwise contaminated beyond the ,
level allowing cleanup through methods
commonly used by pubhc water supply
treatments. The Agency expects to issue
final Guidelines for Ground-Water
Classification during 1988. States then
may use this document for reference in
making ground-water classification and
resource evaluation decisions.
With respect to facility design for
MSWLFs, today's proposal would
establish facility design Criteria that
give States the flexibility to address the
value of ground-water resources in
setting facility-specific design
requirements. Section IX.D of today's
preamble describes the Agency's
approach fop incorporating resource
value considerations into facility design
decisions. EPA is not mandating use of
the ground-water classification system
set forth in EPA's Ground-water
Protection Strategy. Rather, under this
proposal, States would have the
discretion to assess the value of ground-
water resources. In developing Subtitle
D guidance in the future, however, the
Agency may draw upon the Guidelines
for Ground-Water Classification to
provide examples of appropriate
resource evaluation and classification
decisions.
The Agency also is proposing to allow
consideration of resource value in the
corrective action and, to a lesser extent,
the ground-water monitoring
components of today's rule. Specifically,
today's proposal would allow the
ground-water protection standards to be
adjusted by States in situations where
MSWLFs are located over aquifers that
meet certain conditions [see section IX.E
of today's preamble). These conditions
include the following: (1) The aquifer is
not a current or potential source of
drinking water; and [2] the aquifer is not
interconnected with waters to which the
hazardous constituents are migrating or
are likely to migrate in a
concentration(s) that represents a
statistically significant increase over
background concentrations.
Adjustments made to the ground-water
protection standard or cleanup standard
would be made on a site-specific basis
by the State after determining that the
above conditions are met. Furthermore,
the time allowed for corrective action
could vary based on the value placed on
the ground water.
In addition, EPA is proposing that any
frequency of ground-water monitoring
(above the minimum required) be
specified by the State based on site-
specific factors, including the resource
value of the ground water. The proposed
approach, however, would not allow
exemptions from all ground-water
monitoring for facilities located over low
value ground water. The Agency
believes that at least minimal ground-
water monitoring is necessary at all
MSWLFs to evaluate the performance of
facility design and operation and to
identify potential threats to human
health and the environment.
Furthermore, HSWA specifically
mandates that the revised Criteria
require ground-water monitoring as
necessary to detect contamination at
facilities that may receive HHW or SQG
waste. The Agency requests comment
on whether ground-water monitoring
should be waived for MSWLFs located
over ground water of low resource
value.
Finally, EPA believes ground-water-
resource value already plays an
important role in local and State
decisions regarding the siting of
MSWLFs. In this proposal EPA has not
established Federal siting Criteria
specifically based on resource value
because EPA recognizes that resource
value considerations in facility siting are
more appropriately made at the State
and local levels.
The Agency also recognizes that many
States are implementing various ground-
water protection strategies, including
wellhead protection programs. EPA
believes today's proposal provides the
States the flexibility to implement these
programs and encourages them to
increase certain requirements, as
necessary, to meet the objectives of
their wellhead protection programs.
These requirements could range from
more stringent design controls for
mimimizing migration out of a unit to
establishing certain location restrictions,
such as minimum setback distances
from vulnerable municipal well fields.
Comments are requested specifically
on how the resource value of ground
water should be accounted for in setting
the various requirements proposed
today for MSWLFs.
B. Exclusion of Closed MSWLFs
EPA considered whether to apply the
requirements proposed in Part 258 to
MSWLF units that close prior to the
effective date of the final rule. Closed
units are defined in § 258.2 as those
units that no longer receive wastes and
have a final layer of cover material. EPA
believes that inclusion of closed
facilities in this rulemaking would raise
numerous technical, legal, and
implementation complexities that could
not be resolved within the time frame of
this rule. For example, inclusion of
closed units could overtax State
implementation capabilities because
identification of closed facilities would
be difficult and time consuming and
complicated by issues such as changes
in ownership. Thus, EPA proposes that
closed units be excluded from regulation
at this time. The Agency is in the
process of examining questions
regarding closed facilities, however, and
will consider further action once this
effort has been completed.
According to the State Census, a
reported 32,000 closed solid waste
disposal facilities are located across the
U.S., but EPA does not know how many
of these are closed MSWLFs. In the
absence of closed MSWLF regulations,
these facilities, which represent
potential threats to human health and
the environment because of their
number and because many were poorly
designed and managed, may be
addressed under EPA's Superfund
program or by RCRA enforcement
provisions for imminent hazards.
Because the Agency is concerned
about closed MSWLFs, EPA today
encourages each State to develop a long-
term regulatory strategy to deal with
these closed facilities. EPA believes that
developing a closed MSWLF strategy
should include at least the following
steps: 1) Review of the State's legal
authority to address closed facilities; 2)
an inventory of closed facilities to
identify the location of these facilities
and to gather available information on
facility age and size, waste types
disposed of, and known local ground-
water usage; 3) ranking of sites by the
present danger to human health and the
environment;' 4) determination of the-
adequacy of the existing regulatory
controls for closed sites and their ability
to respond to any problems; and 5) use
of the available legislative and
regulatory authorities to address
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FederalRegister /»VoI. 53, No'. 168, Tuesday, August 30, 1988 -^Proposed; Rules *'* ; 33325
problems identified with closed sites.
EPA specifically is interested in
comments on Federal and State
strategies that may be used in
addressing these closed MSWLFs.
C. Practicable Capability
The Congressional directive to revise
the existing Criteria (§ 4010 of RCRA as
amended) states that EPA may consider;
the "practicable capability": of owners
_and operators of facilities that may
receive HHW or SQG waste in
determining what these revisions should
entail, Congress recongnized that the .
universe of owners and operators of
solid waste disposal facilities included
many with limited economic and ;
technical capabilities. For example,
many MSWLFs are owned and operated
by small local governments with limited
resources. Development of today's
proposal, therefore, included an analysis
of how the "practicable capability" of
owners and operators should be taken
into account when setting appropriate
controls for protection of human health
and the environment.
The Agency believes that practicable
capability encompasses both technical
and economic components. The
technical component includes both the
availability of technology for addressing
a particular problem (i.e., technical
feasibility), as well as the technical
capability of the owner or operator to
implement that technology. The
economic component refers to the
economic resources available to the
owner or operator to implement the
revised standards.
To assist in characterizing the
practicable capability of MSWLFs, EPA
collected data on waste disposal,
demographics, landfill size, and landfill
ownership. These data indicate that
most MSWLFs handle relatively small
volumes of municipal solid waste
(measured in tons per day). EPA
estimates that 52 percent of all landfills
manage less than 17.5 tons per day
(TPD) and account for less than 2 ,
percent of the waste handled by all
MSWLFs. However, the largest landfills
(2.6 percent of all MSWLFs) handle
more than 1,125 TPD and manage 40
percent of all municipal landfill waste.
These data also clearly indicate that •
most MSWLFs are located in rural-areas
and these MSWLFs typically serve a
limited number of communities relative
to landfills located in more urban areas.
EPA matched 1982 Census data with
geographic location data (longitude and
latitude coordinates) to determine
whether landfills are located in low-
(rural) or high- (urban) density counties.
EPA estimates that 69 percent of
existing landfills are in counties with
population densities of fewer than 100 - .
people per square mile, supporting the •
conclusion that most landfills are
located in "rural" areas. In addition,
EPA Facility Survey data (Ref. 36) show
that, on average, only 1.8 communities
share a landfill at the village or town
level, but that at the city level, there are
3.8 communities per landfill, ,
To address the economic component
of practicable capability, EPA assessed
the financial capability and current ,
spending;practices of municipal' . ;
governments. EPA assembled financial
,and demographic data from the "1982
Census of,Governments" and the "1983 •
County and City Data Book." Based on „
the 1982 Census data, EPA estimates
that communities typically spend less
than 1 percent of their budgets on solid
waste disposal. In comparison with
other municipal,services, costs at this
level represent a very small obligation.
For example, as an average percentage
of total community expenditures,
communities spend 36 percent on
education, 5 percent on police
protection, and 3 percent on sewage
disposal. The 1982 Census data also
were used to develop a composite score
of nine various financial and economic
vitality measures. This score categorizes
communities' financial capabilities as
weak, average, or strong. EPA used the
score to assess the baseline financial;
condition of governments and the
. economic impact of various regulatory
scenarios. The development and -
categorization of the composite score
and the economic impact analysis is
described.in detail in Section XI of this
preamble and in the draft regulatory
impact analysis for today's proposal.
EPA believes that significant
disruptions of solid waste management,
could result unless these technical and
economic factors are taken into account
where necessary. The Agency, therefore
examined the range of MSWLFs to
determine which, if any, might be
especially susceptible to technical
difficulties or economic hardship.
Owners and operators of two classes of
MSWLFs were identified as possible
candidates for consideration of
practicable capability—existing MSWLF
units and small MSWLFs.
EPA estimates that there are more
than 6,000 MSWLFs currently in
operation. Of these existing facilities,
about 20 percent are expected to close
before 1990 and almost 75 percent are .
expected to close within 15 years (Ref.
10). EPA evaluated whether
requirements should be the same for
these facilities as for new MSWLF units.
Regulating new and existing MSWLF
units differently allows consideration of
practicable capability of the existing
; MSWLF, although some problems at ..; -,
existing facilities may not be addressed
if these units face less stringent
requirements. Regulating new and
existing units the same way, while
conceptually offering greater assurance
of protection, could impose very, high
costs, creating implementation
difficulties andposing the prospect of -'
solid waste management disruptions.
. Comments that ERA received prior to
proposal from States, industry groups,
and priveite firms favored different
requirements for hew and .existing units.
' Based on, these considerations, EPA is
proposing today to vary some
requirements for new and existing
landfill units. These differences fall in
three major areas. First, the majority of
the location restrictions proposed today
would be applicable only to new landfill
units (thait is, units that have not
received wastes prior to the effective "
date of the rule). EPA believes the.-"
application of today's location
restrictions to existing units would
result in significant disruption of solid
waste management in certain areas of
the country* However, existing units
would be required to comply with the
unstable area restrictions (§ 258.15)
because lie Agency believes these
areas posie particular concerns for
protection of human health and the
environment.;
Second, today's proposal does not
require that existing units be retrofitted
with liners and leachate collection
systems. EPA believes that such a
requirement would: (1) Exceed the
economic! capabilities of the majority of
owners and operators of existing / •
facilities, (2) present additional public
health problems from the excavation of ,
waste, and (3) disrupt existing solid
waste management activities.
Third, (today's proposal provides a
phase-in period of 18 months for all
requirements not only to allow States to
• put in place revised regulations, but .also
to provide lead time for owners and
operators to comply with the new
. requirements. Furthermore, additional
phase-in time is provided for ground-
water monitoring due to the resources
needed by States and owners and
operators, to implement this provision. •;
Detailed discussion of the ground-water
monitoring provision is provided in
. Section L£.E of this preamble. ' •, - -
In today's proposal, EPA has not ' ..'.
varied requirements for new and •-'.'•
existing units in bases where such '. -.
.requirements are equally feasible, :
technically and economically, at both
new and existing landfill units, except
existing facilities would have more time :
to compljr with certain requirements. For
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33326 Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
example, the operating criteria (Subpart
C) and ground-water monitoring and
corrective action requirements [Subpart
E) are applicable equally to new and
existing units, although new facilities
must comply with Subpart E's ground-
water monitoring requirements before
they can accept wastes, while existing
units may have up to five years to
comply.
EPA also considered varying
requirements for small MSWLFs. The
Agency estimates that, of the
approximately 6,000 active MSWLFs,
just over half handle 17.5 TPD or less
(Ref. 10]. In contemplating whether to
regulate small MSWLFs differently from
large ones, EPA determined that
practicable capability considerations
did not outweigh potential health and
environmental threats. Specifically, the
Agency believes that size represents
only one factor in determining potential
risk, and that other variables, such as
design and operating controls, location
and climate characteristics, and waste
streams, can be significant determinants
of risk regardless of MSWLF size. Based
on the risk assessment for this
rulcmaking, EPA concluded that no
single factor factor is responsible for
most of the variability in risk across
MSWLFs: rather, there is a complex
interaction among the factors that
govern leachate flux and flow through
the underlying aquifer (Ref. 10). As a
result, EPA is not proposing any special
exceptions for small MSWLFs.
However, the Agency believes that
today's proposal provides States
adequate flexibility to address
particular site-specific conditions
present at MSWLFs, including small
MSWLFs. In addition, the 18-month
phase-in period, along with a State-
specified ground-water monitoring
compliance schedule, should provide
owners and operators of small MSWLFs
adequate time to comply with the
requirements proposed today or to make
other arrangements for solid waste
disposal.
D. Extent of the Criteria Revisions
HSWA directs that, at a minimum the
Criteria revisions require "groundwater
monitoring as necessary to detect
contamination, establish criteria for the
acceptable location of new or existing
facilities, and provide for corrective
action as appropriate." The statute
further specifies that the revised Criteria
shall be "those necessary to protect
human health and the environment and
may take into account the practicable
capability of solid waste disposal
facilities." Because of EPA's mandate to
protect human health and the
environment, the Agency was not
confined to these minimum statutory
requirements (i.e., location restrictions,
ground-water monitoring, and corrective
action requirements) in developing
today's proposal. Limiting the Criteria
revisions to the statutory minimum
would omit important preventive
measures (e.g., gas controls) necessary
for long-term protection of human health
and the environment. Moreover,
exceeding the mimimum reduces the
reliance on detection systems for .
protecting human health and the
environment and thus results in a higher
level of protection.
Furthermore, going beyond the
statutory minimum allows the Agency to
consider other requirements that can
prevent failures and corrective actions,
even though these additional
requirements may add costs for
preventive measures at facilities that
would not have failed and thus did not
need the preventive measures; however,
the Agency has taken into account the
practicable capability of municipal solid
waste landfills in specifying the required
level of environmental controls.
During the development of these
Criteria revisions, EPA received
comments on whether or not the revised
Criteria should exceed the statutory
minimum. In general, industry
advocated confining the scope of the
rule to the statutory nunimum. Several
industry associations, however,
supported an expanded scope as-long as
flexibility was built into the rule and
site-specific factors could be considered
in determining what controls should be
imposed. State views were divided.
Some preferred requiring the statutory
minimum only, while others suggested
varying subsets of additional
requirements, and still others wanted
comprehensive controls.
In today's action, EPA has proposed
revisions that go beyond those
minimally required by HSWA (i.e.,
location restrictions, ground-water
monitoring, and corrective action). In
addition to the statutory minimum,
today's proposal includes an update of
the design and operating criteria in the
existing Part 257 Criteria, and adds new
requirements for closure and post-
closure care and financial responsibility.
The rationale for each of these new
provisions, which the Agency believes
are necessary for the protection of
human health and the environment, is
discussed in detail later in this
preamble. The Agency seeks comments
on the extent of the revisions proposed
today.
E. Requirements for Facilities Other
Than MSWLFs
EPA is concerned about the estimated
28,000 industrial solid waste disposal
facilities and 2,600 construction/
demolition waste landfills, as discussed
previously. However, today's proposal
would limit the applicability of the
revised Criteria to MSWLFs because
there are insufficient data currently
available to develop requirements for
these other facilities. For this reason, the
Agency considered the information-
reporting requirements that might be
appropriate for identifying and
assessing the risks associated with
industrial waste disposal facilities and
construction/demolition waste landfills,
and for determining the need for
additional controls on these facilities.
EPA contemplated three information-
reporting options for these facilities. The
first option was a notification
requirement. Notification could provide
information on these solid waste
disposal facilities, including data on
their locations, ownership, and waste
management practices. This information
could be used to answer basic questions
about these facilities without placing
significant resource demands on the
owners and operators of these affected
facilities or the States. This option,
however, provides no specific data on
the potential environmental or human
health impacts posed by these facilities.
A notification requirement with an
exposure information, component was
the second option. Facilities would be
required to supply exposure information,
such as distance to the property
boundary and available data on the
population that could readily be
exposed. This information could help
EPA and the States roughly assess the
potential risks currently posed by these
facilities and use this information to
select facilities that need more careful
examination and analysis. States should
use this information especially to help
set priorities; however, information
defining potential exposed population
may be of limited utility if not backed by
monitoring results indicating the extent
of any releases that may be occurring.
A ground-water monitoring
requirement was the third option
considered by the Agency.
Comprehensive ground-water
monitoring data could provide a strong
foundation on which to base analyses in
support of rulemaking applicable to
facilities other than MSWLFs. However,
this effort would be resource-intensive
for States and much more costly to the
regulated community then simpler
options. Given the diversity and size of
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..•Federal Register'/ Vol. 53, No. 168, Tuesday, August 30, 1988 7 Proposed Rules'' 33327
this universe of facilities, ground-water
monitoring may not be necessary for all
facilities. While ground-water
monitoring could generate substantial '.
data, EPA believes there are mor.e cost- ,
effective ways of establishing a data
base for rulemaking. EPA believes that
the risks posed by these facilities should
be evaluated more closely before taking
the significant step of requiring ground-
water monitoring at all 28,000 industrial
solid waste disposal facilities and
construction/demolition waste landfills
nationwide. The advantage of a strong
information base is offset by the added
costs and burden imposed on these
facilities for monitoring and the resulting
potential for exceeding the practicable
capability of marginally profitable
operations. Moreover, most States
would have difficulty implementing the,
program due to the extensive resources
it would require and the fact that even
the basic data (e.g., location) on these
facilities are very limited in many
States.
Instead, EPA is contemplating a
phased approach to data collection. The
proposed amendment to Part 257, which
is described in more detail in section
•VEI of this preamble, calls for a .-.--•
notification requirement with a limited
amount of exposure information. Once
these basic data are compiled and
analyzed, the Agency can determine ,
what further information requirements
or regulatory controls should be pursued
for industrial solid waste disposal
facilities and construction/demolition
waste landfills.
VIII. Amendments to Part 257
Today's proposal includes
amendments to 40 CFR Part 257. These
amendments,include: (1) Conforming
changes to Part 257 that would make it
consistent with the proposed Part 258;
(2) an update to the MCLs listed in
Appendix I of Part 257; and (3) a
notification requirement for certain
types of facilities.
A. §§257.1-2 Conforming Changes to
Part 257
Today's proposal adds municipal solid
waste landfills to the list of exceptions
to the Part 257.Criteria contained in
§ 257.1(c). Because MSWLFs would be
covered by the proposed Part 258
Criteria, they would no longer be subject
to the Part 257 Criteria that are generally
applicable to solid waste disposal
facilities and practices. The Part 257
Criteria would otherwise be unchanged
with respect to their applicability, and
would remain in full effect for all other
facilities and practices.
Today's proposal also would add .
certain facility definitions to Part 257.
Included are definitions of the four types
of solid waste disposal facilities that
would be regulated by the Part 257
Criteria: Landfills, surface
impoundments, land application units,
and waste piles. These .new definitions
would clarify that these types of solid
waste disposal facilities are subject to
the Part 257 Criteria. :
B. §§257,3-4 Revisions to Ground-Water
Requirements '
EPA is proposing to update, the MCLs,
which are used as ground-water
protection criteria in Part 257, to include
any MCLs that have been established by,
EPA since the promulgation of Part 257
in 1979. Currently, Part 257 imposes
basic environmental criteria for the ,
protection of human health and the -
environment. At the time Part 257 was
promulgated, the available interim
MCLs for the protection of human
drinking water were included as ground-
water protection criteria. MCLs are
developed by EPA under section 1412 of
the Safe Drinking Water Act (SDWA),
which was amended in 1980. Under the
1986 Amendments to the SDWA, EPA is
mandated to promulgate drinking water
regulations for a large number of
constituents; these regulations generally ,
include MCLs. Accordingly, this notice
would revise the Part 257 regulations to
include any new MCLs as ground-water
protection criteria [including the MCLs
for eight volatile orgahics that were
promulgated on July 8,1987; see 52 FR
25690). Because the development of
MCLs is an ongoing process, EPA is
proposing to simply reference the MCL
regulations (40 CFR Part 141) directly,
rather than update Appendix I, which
how includes only the MCLs
promulgated prior to 1979. Therefore,
today's action proposes to eliminate
Appendix I and to incorporate the MCLs
by reference to 40 CFR Part 141. Using
this approach, the Agency avoids the
need to update the Part 257 Criteria
every time EPA issues a new MCL. The
public would have the opportunity to
comment on whether it would be
appropriate to use each new MCL as a
ground-water protection standard under
Part 257.
C. §257.5 Notification and Exposure
Information Requirements .
The proposed amendments to Part 257
also include a notification and exposure
information requirement for certain
solid waste disposal facilities (§ 257.5).
As discussed above, under this ;
requirement, EPA intends to obtain
notification and exposure information
from a set of solid waste disposal
facilities of particular concern:
Industrial landfills, surface
impoundments, land application units,
and waste: piles, as well as
construction/demolition waste landfills.
As explained earlier, these facilities
are of concern to the Agency" because
they represent a large and diverse set of
solid waste disposal facilities, and little
information is available on these
facilities ait either the State or. Federal
level. In addition, some of these sites /
may be used for disposal of SQG
hazardous! waste and may pose
unknown risks to human health and the .
environment. EPA plans to undertake
data collection efforts on these facilities
to establish the basis for future•'..•'" .
rulemaking. Today's proposed '.;'.. .
-requirement for notification and
exposure information from these
facilities is-a first major step toward •- -. -
revising the current regulatory program
for these facilities. •
The information EPA is proposing to
require from these facilities consists of
two parts: Basic notification information
for facility identification purposes and
limited exposure iriformation to be used-
- to estimate potential risks posed by
these facilities. The notification '
information is necessary because
neither EPA nor the State have adequate
information on these facilities to support
fully revised Criteria for these facilities
at this time. EPA's recent survey of the
States clearly indicates the scarcity of
data on industrial solid waste disposal
facilities and construction/demolition '.-
waste landfills.The proposed
notification requirement would provide
EPA and the States the mechanism to
identify the universe of facilities and, at
the same time, indicate to the facilities
that they are subject to Subtitle D.
The notification also would request
very basic data for determining the
potential risks the facilities present to
human health and the environment. For
example, in addition to seeking general
facility information, the proposed
notification includes two questions .
relating to the potential risks posed by
the facility: The number of households
within onei mile of the facility, arid the
number of.on-site monitoring wells,
Information submitted in response to
these risk-based questions could be,
used by the States in setting priorities
•for inspections and other activities. EPA
requests comments on whether to
include other risk-related questions in
the proposed'nptification, such as •
questions concerning the use of local
waters (ground and surface), the number
of local drinking water wells, and the
number of municipal water intakes
downstream from the facility, In
addition, EPA requests comments
generally on the appropriate questions
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
to be included on the notification form,
and whether the form should be sent to
both EPA and the State.
The proposed notification and
exposure information requirement is
only one part of EPA's data collection
efforts with respect to industrial solid
waste disposal facilities. The Agency
recently has completed a major
telephone survey, and other efforts are
under consideration, such as an in-depth
mail survey, a closer examination of
State regulatory programs, and
collection of available ground-water
monitoring data. The Agency intends to
develop revised Criteria for these
facilities as soon as adequate data are
available to support rulemaking.
IX. Scction-by-Section Analysis of Part
258
A, SubpartA—General
Subpart A discusses the purpose,
scope, and applicability of the proposed
Part 258. It provides definitions
necessary for the proper interpretation
and implementation of the rule and
identifies what Federal laws are to be
considered in complying with these
rules.
1. § 258.1 Purpose, Scope, and
Applicability
Part 258 sets forth minimum national
criteria for (he location, design,
operation, cleanup, and closure of
municipal solid waste landfills. An
MSWLF that does not meet these
criteria would be considered an open
dump for purposes of State solid waste
management planning under RCRA
Open dumping is prohibited under
section 4005 of RCRA.
Part 258 would apply to all new and
existing municipal solid waste landfills,
as defined in § 258.2, except MSWLF
units that closed prior to the effective
date of the rule. As specified in § 258.2,
a closed unit is any solid waste disposal
unit that no longer receives solid waste
and has received a final layer of cover
material. Ait discussed in more detail
later, the Agency believes that final
covers are essential for closure of
MSWLF units. This definition would
ensure that the owner or operator
cannot escape these regulations by
simply refusing to accept additional
waste and abandoning the MSWLF. Part
258 requirements do not apply to units
that are created within the area of
contamination during Superfund actions.
In addition, Part 258 would not apply to
other landfills, or surface
impoundments, waste piles, or land
application units used for solid waste
disposal; these facilities will continue to
be covered under Part 257.
Landfills that receive municipal waste
combustion (MWC) ash regulated under
Subtitle D of RCRA, including MWC ash
monofills, would be considered
municipal solid waste landfills for the
purposes of this rule (see section IX.A.2
of today's preamble). Therefore, today's
proposal applies to any Subtitle D
landfill that receives MWC ash.
However, legislation is currently
pending in Congress which, if enacted,
would require specific standards for the
design of MWC ash disposal facilities
which differ from today's proposed
design requirements. In addition, the
Agency is concerned that certain
requirements proposed today may not
be adequate or appropriate for MWC
ash disposal facilities. For example,
today's proposed air criteria do not
specifically require fugitive dust controls
during MWC ash transportation. Also,
certain ground-water monitoring
parameters (e.g., volatile organic
constituents) and the methane gas
controls proposed today for MSWLFs
may not be appropriate for.MWC ash
monofills due to the characteristics of
MWC ash. In addition, the proposed
daily cover requirements may not be
necessary at MWC ash monofills that
utilize operating controls, such as the
periodic application of moisture to the
landfill surface. The Agency specifically
requests comments on the adequacy and •
appropriateness of today's proposed
requirements for MWC ash disposal.
In a separate effort, the Agency is
developing guidance on MWC ash
disposal. This guidance will provide
additional information regarding the
proper location, design, and operation of
MWC ash disposal facilities.
2. Section 258.2 Definitions
Aquifer. EPA has defined aquifer for
this proposal as a geologic formation,
group of formations, or portion of a
formation capable of yielding significant
quantities of ground water to wells or
springs. This definition is the same one
currently used in EPA's hazardous
waste program and differs from the
original Criteria definition (40 CFR
257.3-4(c)(l)) only in that it substitutes
the term "significant" for "usable." The
Agency has selected this definition for
two reasons: First, because of several
comments received on the ambiguity of
the word "usable," especially with
respect to resource value, and second,
because the delineation of the aquifer is
a site-specific determination. Some
concern has been expressed, however,
that this new definition also is vague
and that the .rule should define
"significant." One possible approach
would be to define "significant" as a
minimum sustained yield of a certain
amount (e.g., one gallon per minute);
however, EPA does not have sufficient
information to determine the amount of
ground water that must be produced to
be considered "significant" in all cases
and believes, therefore, that such a
determination at this time would be
arbitrary. EPA believes such a
determination should be site-specific
and has structured the definition of
aquifer accordingly. The Agency
specifically requests comments on this
approach to defining "aquifer."
Household Waste. Any solid waste,
including garbage, trash, and sanitary
waste in septic tanks, derived from
households is defined as a household
waste. Household include single and
multiple residences, hotels and motels,
bunkhouses, ranger stations, crew
" quarters, campgounds, picnic grounds,
and day-use recreation areas. This
definition is consistent with the. RCRA
Subtitle C regulations found at 40 CFR
261.4.
Lateral Expansion. The Agency has
defined this term to mean any horizontal
expansion of the waste boundary of an
existing landfill unit. Under this
proposal, lateral expansions are treated
as new units and must meet the
requirements applicable to new units.
Under this proposed definition, any area
of any existing unit that has not
received waste by the effective date of
this rule and later receives waste, is a
lateral expansion.
Liquid Waste. Liquid waste, either
bulk or containerized, is defined under
proposed § 258.28(c)(2) as any waste
that is determined to contain free liquids
according to Method 9095 (Paint Filter
Liquids Test) (Ref. 42). This method has
been adopted by the Subtitle C program
in 40 CFR Parts 264 and 265. Because the
solids content of sewage sludge is
readily determined, the Agency
considered using a different definition of
liquids for sewage sludge from publicly
owned treatment works. Under that
alternative, sludges that have a solids
content of 20 percent or greater would
not be considered liquid. That
alternative was considered inferior to
the Paint Filter Liquids Test for two
reasons. First, the variability of sludges
may result in certain sludges meeting
the 20-percent criterion and still being in'
a liquid state or containing free liquids.
Second, the Agency believes that the
Paint Filter Liquids Test is adequate to
ensure that "dry" sludges will not be
eliminated from clisposasl at MSWLFs.
However, the Agency recognizes that
using a solids content measure would
allow easier implementation because it
is a measure commonly used by
POTWs. EPA currently is conducting
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 /Proposed Rules
33329
research to determine if a solids content
measure would be an acceptable
£ abstitute for the Paint Filter Liquids
Test for municipal sewage sludges. EPA
specifically requests any data that will
assist in evaluating the use of a solids
content measure for purposes of this
rule.. .. , :
Municipal Solid Waste LandfilL A
municipal solid waste landfill is defined
as any new or existing landfill or landfill
unit that receives household waste.
These may be publicly or privately
owned. Landfills owned by
municipalities that do not accept
household waste are not MSWLFs;
MSWLFs also may accept other types of
Subtitle D wastes, such as commerical
waste, nonhazardous POTW sewage
sludge, construction/demolition waste,
and industrial solid waste. (Units that
accept only these wastes will be
addressed in future rulemaking
activities.) For example, a unit that
receives primarily construction/
demolition waste, but also receives -
some household waste, is an MSWLF
under this rule. This definition does not
include landfills regulated as hazardous
waste units under Subtitle C of RCRA
and is not meant to capture industrial
solid wate landfills that may receive
office, sanitary, or cafeteria wastes
generated at the site. Finally, the
definition of MSWLFs includes any
landfill that receives MWG ash
including ash monofills (i.e., landfills ,
that receive only ash from MWC
facilities] to the extent that MWC ash is
generated from the combustion of
household waste alone or in
combination with other nonhazardous
wastes. •
3. $ 253.3 Consideration of Other
Federal Laws
. Section 258.3 provides that the owner
or operator of an MSWLF unit must
comply with any other applicable
Federal laws, regulations or
requirements. There are numerous other
Federal laws that must be considered in
siting, designing, and operating
MSWLFs. The owner or operator is
responsible for ensuring that the
requirements of all applicable statutes
arid regulations, as well as, any other
requirements, are met. Applicable
statutes include, but are not limited to,
the following: , ',;'•:
» National Historical Preservation
Act of 1986, as amended.
• Endangered Species Act.
• Coastal Zone Management Act. ;
• Wild and Scenic Rivers Act
"-.« Fish and Wildlife Coordination Act.
• Clean Water Act.
• CleanAir Act. --.-'..
••> Toxic Substances Control Act.
B. Subpart B—Location Restrictions
EPA has identified six types of
locations that require special
restrictions:' sites in the vicinity of
airports, 100-year floodplains, wetlands,
fault areas, seismic impact zones, and
unstable areas. Restrictions for sites
nearairpdrtsand floodplains are
included in the original Part 257 Criteria.
EPA is proposing to add to the revised
Criteria restrictions on siting in
wetlands, fault areas, unstable areas,
, and seismic impact zones because, as •
discussed below, EPA believes that the
additional information that has been
developed and reviewed since
promulgation of the current Part 257
Criteria supports the need for additional
controls in these locations. References
to "new MSWLFs" in this section and
throughout this preamble refer to new
units, as well as to lateral expansions of,
existing units.
1..'Section 258.10" Airport Safety
Under today's proposal, new and
existing MSWLFs located within the
distance limits specified in Federal _
Aviation Administration (FAA) Order
5200.5 [10,000 feet for airports handling
turbojets and 5,000 feet for airports
handling piston-type aircraft]I may not
pose a bird hazard to aircraft. The
proposed requirement is identical to the
current § 257.3-8 and is included
because MSWLFs receive putrescible
wastes that can attract birds despite ,
controls such as daily cover. When solid
wastes are disposed of near airports, the,
birds attracted to the area can present a
significant risk of collisions with
aircraft. The FAA Order 5200.05, "FAA
Guidance Concerning Sanitary Landfills
on or Near Airports" (October IB, 1974]
states that solid waste disposal facilities
have been found by study and
Observation to be attractive to birds
and, therefore, "may be Incompatible
with safe flight operations" when
located near an airport. The background
document relevant to this section (Ref.
2) discusses instances of damage
resulting from bird strikes that have
occurred near landfills.
• The distances derived from Order
5200.5 are based on the fact that over 62
percent of all bird strikes occur below
altitudes of 500 feet (150 meters) and
that aircraft generally are below this
altitude within the distances specified. •
EPA wishes to make it clear that the
"bird hazard" of concern is "an increase
in the likelihood of bird/aircraft
collisions." Thus, EPA expects that solid
waste disposal within the specified
distances would occur only if the
operation can be managed in such a
way as to not increase the risk of
collision within the specified distances.
•EPAreicommends that owners and '•"•-
operators" of MSWLFs consult with the
Fish and Wildlife Service to determine
whether specific facilities pose a bird
hazard,to,aircraft Where appropriate,
this determination should be made in
consultation with FAA, as well as with
the owners and operators of the airports
of concern..
2. Section 258.11 Floodplains
EPA proposes to include a floodplain
requirement in Part 258 that is identical
to the requirement in the current Part
257 Criteria. Thus, EPA is proposing that
new and existing MSWLFs located in
the 100-year floodplain shall not jestrict
the flow of the 100-year flood, reduce
the temporary water storage capacity of
the floodplain, or result in the washout '
of solid waste so as to pose a hazard to
human health and the environment. The
Agency's thinking today is consistent
with the rationale for the original
Criteria., as discussed in 44 FR 53438,
dated September 13,1979. Namely,
disposal of solid waste in floodplains
may have significant adverse impacts:
(1) If not adequately protected from
washout, wastes may be carried by
flood waters and flow from the site,
affecting downstream water quality; (2)
filling in the floodplains may restrict the
flow of flood waters, causing greater
flooding upstream; and (3) filling In the
floodplain my reduce the size and
effectiveness of the temporary water
storage capacity of the floodplain, which
may cause a more rapid movement of
flood waters downstream, resulting in
higher flood levels and greater flood
damageis downstream. For these •
reasons, EPA believes that it is
desirable to locate disposal facilities
outside floodplains. EPA estimates that
14 percent of all existing MSWLFs are
located in 100-year floodplains. The
Agency made this estimate by mapping
MSWLFs nationwide and determining
how mainy MSWLFs fell in areas
mapped! as floodplains. Case studies,
discussed in the background document '•
for this section (Ref. 2), indicate that
landfill!! are subject to design and
operational failures as a result of
flooding.
Today's proposal would require that
new and existing MSWLFs, if located hi
a 100-year floodplairi, be designed and
operated to prevent the adverse effects
described above. EPA recognizes that
locating; MSWLFs in floodplains can be
•expected to have some impact on the
flow of the 100-year flood and water
storage capacity, regardless of
precautions taken. The intent of today's
proposed requirement is to require that
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
MSWLFs not cause significant impacts
on the 100-year Good flow and water
storage capacity. Site-specific
information should be used to evalute
whether a facility has met this standard.
Consistent with the original Criteria,
Part 258 as proposed today would define
the floodplain using the 100-year flood
level. This criterion would limit the
chance for site inundation and increased
flood levels and damages. The intent of
this criterion is the same for Part 258 as
it was for the original Criteria: (1) To
require an assessment of any new or
existing disposal site or expansion of
any existing site in a floodplain to
determine the potential impact of the
disposal site on downstream and
upstream waters and land; (2) to
prohibit such disposal activities if the
site, as designed, may cause increased
flooding during the 100-year flood; and
(3) if the disposal site is located in a
floodplain, to require the use of
available technologies and methods to
protect against inundation by the base
flood and minimize potential for adverse
effects on water quality and on the
flood-flow capacity of the floodplain.
This approach conforms with the
intent of Executive Order 11988, dated
May 24,1977, concerning floodplain
management. Federal agencies are
required to comply with this Executive
Order, and State agencies are
encouraged to develop and apply similar
policies and to consider the provisions
of the Unified National Program for
Floodplain Management of the Water
Resources Council in formulating and
applying State policies.
In order to determine whether a unit is
located in the 100-year floodplain,
owners and operators should use flood
insurance rate maps (FIRMs) developed
by the Federal Emergency Management
Agency (FEMA) under the Federal
Insurance Administration (FIA)
pursuant to the National Flood
Insurance Act of 1988. FEMA has
developed FIRMs for approximately 99
percent of the flood-prone communities
in the United States. FIRMs can be
obtained at no cost from the FEMA
Flood Map Distribution Center, 6930 (A-
F) San Tomas Road, Baltimore,
Maryland, 21227-6227. In areas of the
country where FIRMs are not available,
there are numerous other sources of
floodplains maps, which include: The
U.S. Army Corps of Engineers, the Soil
Conservation Service, the National
Oceanic and Atmospheric
Administration, the U.S. Geologic
Survey, the Bureau of Land
Management, the Bureau of
Reclamation, the Tennessee Valley
Authority, and State and local flood
control agencies or other departments.
When floodplains maps cannot be
obtained from any of these sources, the
owner or operator, with the assistance
of a qualified professional firm, can
determine flood-flow frequency using
Water Resources Council Bulletin
Number 17A (1977), Guidelines for
Determining Flood-Flow Frequency.
EPA is requesting information on the
problems associated with locating
facilities in areas subject to frequent
flooding (e.g., in five- or ten-year
floodplains). The Agency is concerned
about locating facilities in such areas
because EPA believes that frequent
flooding may result in erosion,
undermining, and eventual washout of
the facility. Engineered systems for
preventing such occurrences, therefore,
would be subject to frequent '
maintenance. EPA's existing Subtitle C
regulations allow facilities hi a 100-year
floodplain if precautions to prevent ,
washout have been taken similar to
today's proposal. However, the Agency
currently is considering revisions to its
Subtitle C requirements for locating
hazardous waste facilities in
floodplains. A ban on MSWLFs hi areas
subject to frequent flooding could affect
large portions of the nation, including
the majority of some States, and, thus,
could strain the regulated community's
ability to provide adequate disposal
capacity for municipal solid waste in
those areas. Therefore, a total ban on
siting hi floodplains for Subtitle D is not
deemed appropriate. The Agency is
requesting comment on locating
facilities in areas of frequent flooding.
3. Section 258.12 Wetlands
Today's proposal includes provisions
that no new MSWLF units can be placed
in wetlands unless the owner or
operator makes specific demonstrations
to the State that the new unit: (1) Will,
not result in "significant degradation" of
the wetlands as defined in the CWA
section 404(b)(l) guidelines, published at
40 CFR Part 230, and (2) will meet other
requirements derived from the section
404(b)(l) guidelines. Existing facilities
that are located in wetlands could
continue to operate.
EPA believes that these stringent
restrictions are necessary to protect
human health and the environment
because of the potential damage caused
by siting MSWLFs in wetlands. The
background document to the rule
describes the threats posed when
MSWLFs are located hi wetlands (Ref.
2). Moreover, within recent years the
Agency has identified wetlands
protection as a top priority, specifying
aggressive implementation of the Clean
Water Act section 404 program,
increased coordination with and
consistency of Federal and State
policies, and other measures as may be
necessary. To this end, the Agency
considers today's proposed action as •
essential measure for protecting wetland
resources.
Today's proposed action is based on
existing Agency wetland policy as
expressed in the 40 CFR Part 230
guidelines; Executive Order No. 11990,
Protection of Wetlands; and the January
23,1986, Memorandum of Agreement
(MOA) between EPA and the Army
Corps of Engineers, which addresses the
disposal of solid waste in wetlands
under RCRA. The 1986 MOA represents
an interim arrangement for controlling
solid waste disposal in waters of the
U.S., including wetlands. In the long
term, the expanded RCRA solid waste
.regulations proposed herein will help
play a key role in protecting wetlands
from the unregulated disposal of waste
materials.
EPA's Part 230 guidelines are the
regulations that specify the analytical
tools and environmental criteria to be
used when determining whether to issue
Clean Water Act section 404 permits for
proposed discharges of dredged or fill
material in waters of the United States,
which include most wetlands. To be
consistent with the Act, the provisions
proposed today hi § 258.12 adopt the
definition of wetlands contained hi the
Army Corps of Engineers (the Corps)
section 404 implementing regulations (33
CFR Parts 320 through 330) and the EPA
section 404(b)(l) guidelines (40 CFR Part
230). EPA believes that consistency with
this definition will aid in implementing
the MSWLF provisions. As defined by
EPA and the Corps, wetlands are those
"areas that are inundated or saturated
by surface or ground water at a
frequency and duration sufficient to
support, and that under normal
circumstances do support, a preyalance
of vegetation typically adapted for life
in saturated soil conditions. Wetlands
include, but are not limited to, swamps,
marshes, bogs, and similar areas."
Today's proposed action adopts the
four major requirements of the
guidelines: (1) The practicable
alternatives test, (2) lack of significant
degradation; (3) compliance with other
applicable laws, and (4) minimization of
adverse effects. The guiding precept of
the guidelines is that discharges into
wetlands should not be allowed unless
the owner or operator can demonstrate
that such discharges: (1) Are
unavoidable, i.e., there are no
practicable alternatives to discharging
hi wetlands; and (2) will not cause or
contribute to significant degradation of
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wetlands. In particular, the guidelines
identify filling operations in wetland? as
among the most severe environmental
impacts covered. For this reason, EPA
believes that these guidelines should be
used to provide the basis for today's
proposal. Moreover, these guidelines are
in keeping with Agency policy of .._.'.-•
maintaining consistency among different
EPA programs.
The guidelines in § 230.10(a) state that
"no discharge of dredged or fill material
shall be permitted if there is a ... .
practicable alternative to the proposed
discharge would less adversely impact
on the aquatic ecosystem, so long as the
alternative does not have other
significant adverse environmental
consequences." Ah alternative is
practicable if it is: (1) Available and (2)
feasible, i.e., capable of satisfying the
basic or overall purpose of the proposed
project, taking cost, logistics, and
technology into consideration. For
activities that are not water-dependent,
i.e., do not require access or proximity
to wetlands to fulfill their basic purpose,
the guidelines further provide that: (1)
Practicable alternatives that do not
involve wetlands are presumed to be
available, unless clearly demonstrated
otherwise; and (2) where a discharge is
proposed for a wetland, all practicable
alternatives that do not involve a
discharge to a wetland are presumed to
have a less adverse impact on the
aquatic ecosystem, unless clearly
demonstrated otherwise. Both of these
rebuttable presumptions place a burden
on the permit applicant to demonstrate
that no practicable alternatives exist.
In addition to the practicable
alternatives test, the guidelines also
require that "no discharge of dredged or
fill material shall be permitted which'.
would cause or contribute to significant
degradation of the waters of the United
States," including wetlands (40 CFR
230.10(c)). Under the guidelines, effects
contributing to significant degradation
considered individually or cumulatively '
include significant adverse effect on: (1)
Human health or welfare; (2) life stages
of aquatic life and other wetland-
dependent wildlife; (3) aquatic
ecosystem diversity, productivity, and
stability, e.g., a wetland'^capacity to
assimilate nutrients, purify water, or
reduce wave energy, and (4)
recreational, aesthetic, and economic
values.
Third, § 230.109(c) of the guidelines
states that a, discharge of dredged or fill
material shall not be permitted if it: (1J
Causes or contributes to violations of
any State water quality standards; (2J
violates applicable toxic effluent
standards or other Clean Water Act
Section 307 standards; (3) jeopardizes ,
species or habitat protected under the
Endangered Species Act; or (4) violates
any requirement imposed by the
Secretary of Commerce to protect
marine sanctuaries under the Marine
Protection, Research, and Sanctuaries
Act. . .-
Moreover, the guidelines provide that
a permit should not be issued unless
appropriate and practicable steps have -
been taken to minimize potential
adverse impacts of the discharge into
wetlands (40 CFR 230.l6(d)). Subpart H
of the guidelines lists examples of this
many types of actions that can be -
undertaken to minimize the adverse
effects of discharges of dredged or fill
material.
Because construction of a new landfill
essentially is a rilling operation, it
destroys the wetland, which generally
cannot be restored due to the
complexities and fragility of the
ecosystem,! EPA also believes that it is
essential to preserve the ecological
function of the remaining wetland at an
existing facility. Thus, unless the owner
or operator can make the demonstration
specified in § 258.12(a), new facilities
and lateral expansions of existing
facilities into wetlands are banned. This_
demonstration is similar to those
established by EPA in the section
404(b](l) guidelines at40CFR230.10;
The importance of these demonstrations
' is discussed below. .
With regard to an owner, or operator
who wishes to site a new facility or:
expand an existing facility in wetlands,
today's proposal essentially adopts the
restrictions on discharges contained in
§ 230.10 of the guidelines and requires
them in the form of prior demonstrations
to be made to the State-Failure to make
any of the following demonstrations will
bar the MSWLF from being sited in a
wetlands.
First, the MSWLF owner or operator
must consider and evaluate alternative
sites outside of wetlands and
demonstrate that no environmentally
acceptable "practicable alternative" is
available. As discussed above,
§ 230.10{a) of the guidelines provides
guidance on the meaning of the term
"practicable alternatives." Since a
landfill is not a water-dependent
activity, the guidelines presume that: (ij
Alternatives that do not involve locating
MSWLFs hi wetlands are available, and
(2) such alternatives have a less adverse
impact on the aquatic ecosystem. These
presumptions make the alternatives
analysis a rigorous test for the MSWLF
owner or operator to meet.
Second, the MSWLF owner or
operator must demonstrate that siting
the landfill in the wetland will not cause
or contribute to "significant
degradation" of me wetlands, as defined
; in 40 GER 230.10(b). Third, the owner or
operate* must ensure that siting in the
wetlands does not violate any
provisions of the applicable laws
specified in § 230.10(c).
Fourth, the MSWLF'owner or operator
must demonstrate thai,' if the MSWLF is
sited in the wetland after satisfying 40
CFR 230.10 (a), (b), and (c), appropriate
and practicable .steps have been taken
to minimize potential adverse impacts of
the'MSWLF on the wetlands. These may
include careful'decisions with respect to
the splii^ waste to be disposed of, any
protective technology employed, :
attention to plant and animal
populations, and measures that mitigate
unavoidable impacts on wetland values.
The guidelines identify a number of
! possible! measures.
Finally, the owner or operator must
show that sufficient information is •
available for making reasonable
determinations with respect to these
demonsltrations; otherwise, the owner or
operator cannot make the ",
demonsliations necessary.to qualify for
the waiver to the ban. This last
requirement places the burden for
making 'the. required demonstrations
squarely on the MSWLF owner or
operatd]!. :
EPA recognizes the burden .that these
requirements place on the MSWLF
owner OP operator who wishes to site a
new facility, or expand an existing one,
; in wetlands* EPA believes, however,
that the-nation's wetlands are sensitive
ecosystems that merit the protection
afforded by these requirements. For this
reason, the Agency proposes that.no
new MSWLFs (including internal
expansions of existing MSWLFs] should
be located in wetlands unless the
MSWLPs meet the stringent waiver
requirements. Comments are requested
on the proposed ban and on the
demonstration Criteria;for the waiver.
Since the EPA section 404(b](l)
guidelines are prospective in nature,
they do not address, or apply to, the
quesHoti'of existing facilities located in
wetlands. The issue is whether, and to
what extent, the revised Criteria should
prohibit pr otherwise restrict the
operation of existing MSWLFs.
EPA recognizes that requiring existing
MSWEFsi in wetlands to close'would not
generally'restore the ecological function
of the wetland. J^urther, requiring
existing units in wetlands to close would
adversely imapct Waste disposal
capacity.rEPA estimates that
approximately 6 percent of all MSWLFs
are inwetlands. This estimate/was
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
developed by correlating maps of
wetland areas with MSWLF locations.
The Agency welcomes additional data
that commenters may wish to supply
concerning the number of MSWLFa sited
in wetlands.
In developing the wetlands
requirements for this proposal, EPA
sought to balance the need to protect the
fragile ecosystem with the practicable
capability of owners and operators of
MSWLFs. EPA recognizes that in some
parts of the country, large areas fall
within the definition of wetland. In these
areas, a ban on the maintenance of
existing facilities in wetlands could
have great detrimental effects on waste
management in communities and could
possibly encourage inadequate
alternatives to be implemented.
For existing facilities, EPA is not
proposing to require closure and/or
removal of waste. The existing Subtitle
C standards do not specifically address
wetlands, but the Agency intends to
propose revisions to these standards hi
the future. The Agency believes that
closure and/or removal of waste is not
viable for MSWLFs located in or
adjacent to wetlands because this
approach would result in significant
Impacts on disposal capacity and cause
major disruptions hi current municipal
solid waste management. There would
be reduced capacity if MSWLFs located
in wetlands were required to close and
siting of MSWLFs in those States where
large areas are included under the
definition of wetlands would be
substantially hindered. The Agency
believes the approach proposed today
for existing MSWLFs in wetlands
properly considers disposal capacity
concerns and the practicable capability
of MSWLF owners and operators.
4. Section 258.13 Fault Areas
EPA proposes to ban the siting of new
units of MSWLFs in locations within 60
meters (200 feet) of faults that have had
displacement in Holocene tune. (The
Holocene is a geologic time unit, known
as an epoch, that extends from the end
of the Pleistocene to the present and
includes approximately the last 11,000
years.) This requirement would be
consistent with the existing location
standard for hazardous waste facilities
under Subtitle C; EPA has concluded
that it is appropriate to impose the same
requirement on MSWLFs because EPA
believes that faults also may adversely
affect the structural integrity of
MSWLFs.
Earthquakes present a threat to public
safely and welfare in a significant
portion of the United States. Damage
and loss of life in earthquakes occur as
a result of surface displacement along
faults (surface faulting) and ground
motion (shaking), as well as secondary
effects of the shaking such as ground or
soil failure. Today's proposed standard
is designed to protect facilities from
deformation (i.e., bending and warping
of the earth's surface) and displacement
(i.e., the relative movement of any two
sides of a fault measured in any
direction) of the earth's surface that
occur when the fault moves. The best
protection for MSWLFs is to avoid faults
subject to displacement and the zone of
deformation.
The Agency is not proposing a
standard for existing MSWLFs located
over faults. EPA considered requiring
existing units located over faults to
close over a period of time; however,
insufficient information exists that
would justify the closure of these units.
EPA requests comment on this issue.
The effects of deformation drop off
rapidly as distance from the fault
increases. Since the greatest degree of
deformation occurs along the fault with
the greatest displacement (usually the
main fault), the farther away the
MSWLF is from the main fault, the less
likely it will be affected by deformation.
Studies of main fault traces (i.e., faults
that had most displacement in an area)
suggest that most deformation occurs
within 60 to 90 meters of faults that have
had displacement in Holocene time.
Since the 60-meter setback is measured
from any fault, not just the main fault
trace, EPA believes that a 60-meter
distance from any Holocene fault
(surface or subsurface) would provide
ample protection against the effects of
deformation. If a facility is located near
a fault, containment structures (liners,
leachate collection systems, and final
covers) may be inadequate to prevent
release of solid waste and hazardous
constituents during an earthquake.
Outside of this zone, ground motion will
be less severe, and containment
structures designed to withstand ground
motion, as specified in § 258.14
(described below), should be adequate
to protect human health and the
environment.
Holocene faults are faults that either
were created or experienced
displacement in Holocene tune. The
faults are a concern because the
geologic evidence indicates that faults,
that have been moved in recent times,
i.e., during Holocene tune, are the ones
most likely to move in the future. Faults
that have had displacement hi Holocene
time are easier to identify and date in
the field than older faults because this
epoch produced recognizable geological
deposits, and erosion and deposition
surfaces. These faults are identifiable by
fault scarps, offset streams, mole tracks,
furrows, and fault traces on young
surfaces with ground-water barriers
marked by spring alignments and
vegetation contrasts.
EPA's definition of "fault" is intended
to include main, branch, or secondary
faults. This definition would include
both faults that appear at the surface
and those that do not have surface
expression (including the small fault
planes associated with surface faults).
Because only faults that have
experienced displacement in Holocene
time are of concern in this standard, a -
subsurface or surface fault that has not
disturbed the Holocene deposits is not
included in the definition.
In some areas of the country,
Holocene deposits and landforms are
scarce, such as areas where glacial
activity has stripped the surficial ground
cover and left highly resistant rock, so
inspection of Holocene deposits and
landforms will not yield enough
evidence to conclusively determine
whether there has been recent faulting
activity. In these situations, reference to
seismic epicenter plots and historic
records may be needed, and
identification and close examination of
possible fault-related features expressed
in Pleistocene and older deposits may
be necessary as well.
In 1978, the U.S. Geological Survey
mapped the location of Holocene faults
in the United States (Ref. 2). Maps of
identified Holocene faults in the United
States also are available from the States
of California and Nevada. Based on
these maps and maps of MSWLFs, EPA
estimates that 35 percent of all MSWLFs
are hi counties that contain faults that
have been active in the Holocene,
putting a large number of MSWLFs in
potentially threatened areas. However,
the Agency does not have data showing
how close landfills located in these
counties are to the active faults.
The current Subtitle C regulations for
hazardous waste facilities have the
same location restriction being proposed
hi today's rulemakiug. The Agency
believes that this standard also is
appropriate for MSWLFs because faults
also present concerns relating to failure
of containment structures for MSWLFs.
In addition, the Agency believes that a
similar ban is within the practicable
capability of new MSWLFs because the
area of the nation within 60 meters from
a Holocene fault, i.e., the banned area, is
limited. EPA requests comment on both
the general concept of a location
restriction based on fault areas and the
specific 60-meter setback requirement.
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33333
5. Section 258.14 Seismic Impact Clones
Today's proposal would require the
owner or operator of a new MSWLF unit
,- in a seismic impact zone to design the
unit to resist the maximum horizontal
acceleration in hard rock at the site.
Seismic impact zones are defined as
'. areas having a 10 percent .or greater
probability that the maximum expected
horizontal acceleration in hard rock,
• expressed, as a percentage of the earth's
gravitational pull (g), vyill exceed O.lOg
,in 250 years. -
The National Oceanic and .
Atmospheric Administration and others
have documented structural damages"
resulting from earthquakes. The
potential for damage to MSWLFs from
earthquakes can be deduced from
similar structures damaged by :
earthquakes; Such damage includes
cracks in foundations and complete
collapse of structures. EPA believes that
the adverse impact of siting MSWLFs in
seismic areas justifies the need for a
comprehensive standard to prevent
releases from these facilities. .Types of
failure that may result from ground
motion are: (1) Failure of structures from
ground shaking; (2) failure of unit
components due to soil liquefaction,
liquefaction-induced settlement and •
landsliding, and soil slope failure in
foundations and embankments; and (3) .
landsliding and collapse of surrounding
structures. The background document
supporting this section of the rule (Ref.
2) provides examples of the potential
adverse effects on MSWLFs that may
occur in seismic impact zones. The
Agency believes that these failures may
result in contamination of air, ground
water, surface water, and soil.
Therefore, in order to protect human
health and the environment, all
: containment structures, including any
liners, leachate collection systems, and
surface water control systems at new
MSWLFs, must be designed to
withstand the stresses created by peak
ground acceleration at the site from the
maximum earthquake based on regional
studies and site-specific analyses.
The Agency's'proposed requirement
translates to a 4-percent probability of
exceeding the maximum horizontal
acceleration in 100 years. The Agency
believes that the areas affected by the
proposed "seismic impact zone"
requirement represent the areas of the
United States with the greatest seismic
risk, and, therefore, this proposal would
be protective of human health and the
environment.
The proposed performance
requirement would minimize the risk of
slope and liner failure due to seismic
activity. By minimizing the risk of failure
of the landfill slopes, the potential for,, !
exposure of solid waste to the
atmosphere and the possible
contamination of run-off by contacting
exposed solid waste also would be
reduced. The Agency further believes
that today's proposal would reduce the
potential for contamination of ground
water beneath the landfill resulting from
failure of a liner. •
Although § 258.13 of today's proposal
would prohibit siting new units on or.
adjacent to active Holocene faults
(faults that have had displacement in
Holocene time) to protect against ;
releases of wastes from facility failure,
due to fault rupture, this standard does
not address damagevthat may occur as a
result of earthquake-induced ground
motion. Studies indicate that ground
motion is more important as a failure
mechanism than fault rupture, and not
all earthquakes are manifested by .
surfaceiaulting (Ref. 2). Ground motion
resulting from earthquakes without
associated surface faulting has been
found hi some cases to be two or three
times that associated with quakes with
faulting. . ' • -
Maps depicting the potential seismic
activity across the United States at a
constant-probability level have been
prepared (U.S. Geological Survey Open-
File Report 82-1033). The maps indicate
that certain portions of the country are
at a.higher level of seismic hazard than.:
other areas. For example, portions of the
eastern U.S., although not subject to
frequent earthquakes, are ata higher ,
level of seismic hazard than portions of
the western U.S.
The process of designing earthquake-
resistant components may be divided
into three steps: (1) Determining
expected peak ground acceleration at,
the site from the maximum quake, based
on regional studies and- site-specific
seismic risk analysis; (2) determining
site-specific seismic hazards (e.g., soil
liquefaction); and (3) designing the
facility to withstand peak ground
accelerations. Various methods for
accomplishing the above steps are
available. Methods appropriate to
individual MSWLFs should be selected
by the owner or operator, subject to
State approval.
While the existing Part 257 Criteria
and current Subtitle C requirements do.
not address seismic impact zones,
additional location restrictions for .
hazardous waste disposal facilities
under Subtitle C of RCRA are being
developed, and a standard consistent
with today's proposal is being
considered. The Agency believes that
• this standard is appropriate for
MSWLFs because the concerns relating
-toiailure'of containment structures ar.e
the same for any .landfill regardless of
waste type; The Agency requests ,
comment on the approacirproposed _- '.'
today. V
6. Sectioii 258.15 Unstable Areas
EPA is'proposmg to require owners
and operators of new and existing
MSWLF units located in* unstable areas '
to demonstrate to the State the
structural stability of the unit. This
demonstration must, show that' i
engineering measures have been
incorporated into the design of .the unit .
to mitigate the potential adverse impacts
on the stractural components of the unit
that mayj result from destabilizing
events.:; ,
Struchiral components include liners,
leachate collection systems, final -.--.-.
covers, arid run-on and run-off collection
systems. Facilities located in unstable
areas maiy require extensive repairs
arid/or corrective action; folio wing the
.occurrence of a natural or human-
.induced destabilizing:event. EPA has i
reviewed documented events that
illustrate^ the problems of locating waste
management units in unstable areas
(Ref. 2). The impacts resulting from
naturalcir human-induced destabilizing
events observed include rapid
dispersion of contaminants over a large
area, contamination of municipal water
supplies; and seepage of Contaminants -
into basements. :
EPA isi proposing to define an
unstable area as a location that is
susceptible to natural or human-induced
events or forces capable of impairing the
integrity of the landfill structural
components responsible for preventing
releases,: These areas could include: (1)
Subsidence-prone areas, such as areas
subject to the lowering or collapse of the
land surface either locally or over broad
regional areas; (2) areas susceptible to
mass movement where the downslope
movement of soil and rock under
gravitational influence occurs; (3) weak
and unstable soils, such as soils that
lose;their ability to support foundations
as a residt of expansion or shrinkage;
and (4) Karstterrains, which are areas
where solution cavities and caverns ,
develop in limestone or dolomitic
materials. ' / ,
'• National maps are available that
locateKarst terrairis'andlandslide- , .
susceptible areas, but weak and
unstable! soils and subsidence-prone
areas'appear to be mapped only • ;
individually or at the local level. Thus,
identification of existing MSWLFs hi
these un.stable areas, and determination
of whether the proposed site of a new
MSWLF is in an unstable area, would
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
take place on. a case-by-case basis
•where geographic delineation of these
areas is not available on a national
scale.
A detailed description and discussion
of each of the types of unstable areas
identified is contained in a background
document (Ref. 2} and a brief summary
of each type and the potential threats to
MSWLFs follow.
Subsidence-prone areas are those
subject to surface subsidence because of
natural subsurface conditions, such as
Karat formations, or human-made
subsurface activities, such as fluid
withdrawal or mining. Subsidence at a
facility can result in rupture,
deformation, or other damage to liners
or final covers that may release waste
directly into the environment.
Areas susceptible to mass movements
include areas with evidence of ongoing
slope failure; areas where a small
increase in sihear stress or a small
decrease in shear strength might cause
slope failure; areas where geologically
similar locations in the same general
areas have failed; and areas in the
vicinity of pre-existing slope failures.
Susceptibility to mass movement is
determined from geotechnical and
geologic studies.
"Mass movement" covers a variety of
slope failures and rapid movement of
materials downslope by gravitational
influences including landslides,
avalanches, flows, creeps, solifluction,
block sliding, or a combination of these.
Mass movements are caused by
imbalances between the forces of
gravity (shear stress] acting on the mass
of soil or rook composing the slope and
the shear strength of the mass. Human
activity and natural events can increase
the shear stress acting on the mass and/
or reduce the mass* shear strength,
thereby causing failure. Human-induced
causes of mass movement include, but
are not limited to, construction
operations, seepage from human-made
sources of water, and stormwater
drainage. Naturally occurring slope
failures may be caused by large volumes
of water from intense rains or melting
snows, vibrations and shock waves
generated by earthquakes, frost and
freeze/thaw cycles, or intense drying of
soils. Mass movements, whether
naturally occurring or induced, can
carry a facility downslope, rupture a
facility in place, or destroy facility
control and monitoring systems.
Weak and unstable soils include
unconsolidated deposits subject to
differential and excessive settlement.
This movement under and around a
facility can tear liners, rupture dikes,
render leacliate collection systems
inoperable, and possibly alter the
ground-water flow. '
Karst terrains are areas underlain by
limestone and dolomite and often are
characterized by extensive solution
cavities, sinkholes, and fractures.
Sinkhole formation, which may occur in
certain types of Karst terrains, can
cause rupture of unit liners and covers
and can result in collapse of the facility,
Karst terrains also promote more rapid
movement of leachate from the landfill
due to extensive fractures and
secondary porosity. Based on map
overlays of Karst areas and MSWLF
locations, EPA estimates that 4-percent
of all existing MSWLFs are in Karst
terrain; however, not all Karst terrains
would be considered unstable under
today's proposal.
Under the proposed requirement, the
owner or operator of a new MSWLF
must determine, and demonstrate to the
State, that the proposed site is not
subject to any of these destabilizing
events. This demonstration should be
maintained in the facility file by the
owner or operator as part of the permit
application. The following factors
should be considered in determining
whether an area is unstable: (1) Soil
conditions that may result hi significant
differential settling resulting in damage
and failure of dikes, berms, or
containment structures (for example, the
presence of expansive clays that expand
when wet and shrink when dry); (2)
geologic or geomorphologic features
such as mass-movement-prone areas,
Karst terrains, or fissures that may
result in sudden or nonsudden ground
movement and subsequent failure of
dikes, berms, or containment structures;
(3) human-induced features or events
(both surface and subsurface) such as
areas of extensive withdrawal of oil,
gas, or water from subsurface
formations or construction operations
that may result in sudden or nonsudden
ground movement and subsequent
failure of dikes, berms, or containment
structures; and (4) any other features
that historically indicate that a natural
or human-induced event may impair the
engineered structures of the unit and for
which protective measures cannot be
designed to withstand the event, such as
volcanic activity areas.
EPA is proposing to require this case-
by-case determination of instability
because of the difficulty of clearly
delineating unstable areas on a broad
scale. EPA believes that case-by-case
decisionmaking allows the soundest
analysis under the circumstances.
Subtitle C currently does not address
unstable areas; however, the Subtitle C
rules are being reviewed and standards
consistent with today's proposal are
being considered. EPA believes that
today's standard is appropriate for
MSWLFs because the concerns relating
to failure of containment structures are
the same for any landfill regardless of
waste type.
Because failure of existing units as a
result of destabilizing events in unstable
areas poses potential threats to human
health and the environment, the Agency
is proposing that units that cannot make
the structural stability demonstration be
closed over time. In EPA's view, " -
continued operation of such units would
only increase the possible contaminant
loading on the environment in the event
of failure. In recognition of the
practicable capability of the owner or
operator to secure a replacement site,
EPA is proposing that existing units in
unstable areas close within five years of
the effective date of the rule. Upon
closure, the owner or operator of these
faculties would not be required to
remove the waste from the unit because
removal of the wastes involves certain
risks, and EPA believes removal of the
wastes would be a great burden and
expense to owners and operators and
would exceed the practicable capability
of the regulated community.
EPA has selected five years as a
phase-out period based upon the belief .
that five years is adequate time for
proper facility closure and for siting and
construction of a new facility hi an
acceptable location. The activities that
EPA expects to occur during this period
include hydrogeologic investigations
and site selection, land acquisition, and
design, permitting, and construction of
the new facility. The Agency is unable
to estimate the number of facilities that
would be affected by this requirement.
EPA requests comments on the concept
of a phase-out period, the appropriate
length of the phase-out period, and the
number of facilities affected.
EPA recognizes that, in some cases, it
may not be possible to find a suitable
site and construct a replacement
MSWLF within five years. To address
this situation, EPA also is proposing a
variance to the required phase-out that
would allow the State to extend (but not
waive) the five-year period if no
"practicable alternative" is available
and if the existing MSWLF unit will not
pose a substantial risk to human health
and the environment. The Agency
believes this variance is appropriate and
justifiable under section 4010 of RCRA,
which allows EPA to consider the
"practicable capability" of facilities to
comply with the Criteria. The variance
would allow for State flexibility to
, determine the length of the time
extension and to require any interim
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Federal gegisJer'fVol.. 53, No. 168, Tuesday, August 30, 1988 / Proposed :Rules 33335
controls necessary to protect human
health and the environment. During the
extension period, the owner or operator
would be responsible for meeting all '•-'
other applicable requirements in today's
proposal.
In Deciding whether to grant a
variance, EPA would expect the State to:
consider whether (1) it currently is not
economically feasible to find, develop,;
and operate a'new site; (2) it currently is
not logistically feasible to locate a new
MSWLF in a more suitable area (e.g., the
only -suitable property is already : :
developed or is located too far from
Collection centers};: 6r (3) legal barriers
exist to the siting, acquisition, or
operation of-the landfill in suitable areas
{e.g., jurisdictional restrictions do not
allow wastes from one municipality to
be disposed of in the jurisdiction of
another). If such conditions exist, and
the risks associated with continued
operation during the extended period of
time do not pose undue threats to /
human health and the environment, a
variance may be appropriate. A specific
risk level is not being proposed because
the Agency believes that such a decision
is best left to the States, who must.
weigh the various alternatives. •
.': The Agency recognizes that States
may interpret the above criteria in
various ways, and that decisions may be
- based on site-specific conditions. The
Agency believes that this is appropriate,
since the States are in-a better position ;
than EPA to determine whether a
specific facility should be granted an
extension. -
. Although it may be difficult to site a
new MSWLF within the proposed five-
year period, EPA does not intend that
States grant unlimited time extensions
to units located in unstable areas.
Various alternatives, such as . ,
regionalization of disposal facilities,
recycling and source reduction,
municipal waste combustion (i.e.,
incineration), and the use of transfer
stations, are available to manage
wastes. These alternatives can be used
to overcome environmental, logistical,
legal, or economic barriers to siting new
landfills. . :
, EPA requests comments on whether
other location restrictions such as these
or others in addition to those proposed
today should be imposed for MSWLFs. '•,
C. Subpart C^—Operating Criteria •
The requirements of this Subpart
would apply to all new and existing \
MSWLFs. These requirements address .
day-to-day activities, such as
application of daily cover (necessary to •'•
reduce immediate threats to public
health), and long-term activities, such as
post-closure care (necessary to minimize
or eliminate the possibility of the release
of contaminants to the environment).
1. Section 258.20 Procedures for
Excluding the Receipt of .Hazardous ;
Waste • '
Section 258.20 of today's proposal
would require the owner or operator of
an MSWLF to implement a program to
detect and prevent attempts to dispose -
of hazardous wastes (regulated under
Subtitle C of RCRA) and PCB wastes at
the facility (regulated under the Toxic ;
Substances Control Act). EPA does not
•intend for this regulation to limit the
- legal disposal in MSWLFs of very small
quantity generator (VSQG) hazardous
waste (hazardous Waste generated at a
rate of less than 100 kg per month),
certain wastes containing PCBs at
concentrations less than 50 ppm, arid ,
empty pesticide containers that have
been properly .rinsed in accordance with
the label instructions as specified under
the Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA) and
regulations in 40 CFR Part 165. Today's
proposal also does not restrict the .
disposal in MSWLFs of HHW, which is
exempt from EPA's hazardous waste
rules; however, the Agency strongly
endorses HHW collection programs and
recommends the management of
collected HHW in hazardous waste
management facilities.
With regard to the disposal of PCBs,,
regulations promulgated under the Toxic
Substance Control Act (TSCAJ specify
MSWLF disposal as proper for limited :
categories of PCB materials. Such •
materials include drained PCB-
contaminated electrical equipment (i.e.,'
equipment that formerly contained 50 to
500 ppm of PCBs in dielectric fluids),
drained hydraulic and heat transfer
equipment, and "PGB articles" (see 40
CFR 761.3 and 761.60(b)(5)) that
previously contained 50 to 500 ppm of
PCBs and that have been drained of - -,-
free-flowing liquids. Most significantly,
TSCA disposal regulations generally
allow the disposal in MSWLFs of "small ,
capacitors" that contain less than three
pounds of PCB dielectric. These small
capacitors frequently are found in
fluorescent light ballasts, high-intensity
discharge lighting power supplies, and a
variety of consumer appliances, such as
microwave ovens and air conditioners.
" Measures that MSWLF owners and
operators must incorporate in their -
programs to exclude receipt of
hazardous waste include, at a minimum,
random inspections of incoming loads,
inspection of suspicious loads,
recordkeeping of inspection results,
training of personnel to recognize
hazardous waste, and procedures for
notifying the proper State authorities if a
regulated hazardous waste is "found at:
the facility. The State may require
additional program elements.
The random load checking program is
a crucial deterrent to illegal disposal. ...-
Such a program might include
designation of an inspector to examine
several random loads throughout facility
operations. The loads could be ;
discharged at a designated location ;
separate from landfilling Operations, •
broken down with hand tools, and
visually^inspectedfor indications that
suspicious containers may hold Subtitle
C hazardous wastes. The rule could
require that records be kept of each load
mspection. The records should include
the date, time, name of the hauling firm, .
driver, source of the waste, vehicle
identification numbers, and all
observations made by the inspector.
Each MSWLF would be required to
train all necessary personnel to identify
potential sources of Subtitle C ...,".'
hazardous wastes. At a minimum,:this
should include supervisors, spotters, -
designated inspectors, equipment
operators, and weigh station attendants.
The training should emphasize;
familiarity with containers and labels ,
typically used for hazardous wastes arid
other hazardous materials. If Subtitle C
hazardous waste is found in any load
mspecteid, or otherwise found at the
.facility, the owner or operator should
promptly notify the State. The owner or.
operator should .cordon off the area
where the material was deposited and
make efforts to carry, out proper
cleanup; transport, and disposal of the
material! at a permitted hazardous waste ,
management facility. •
In developing this proposal, EPA .
considered specifying the program in -
-detail, delineating all activities and
procedures needed to exclude
hazardous waste. The Agency decided
against a strictly defined program
because each landfill will receive,'
different amounts of waste that could
contain questionable material. Today's
proposal gives States and MSWLF
owners and operators flexibility in
implementing this requirement. '
2. Section 258.21Cover Material ;
Requirements'". , \.
EPA proposes to strengthen the cover
;material criterion imposed under
§ 257.3-iB of the existing Subtitle D
Criteria to require the application of
suitable cover material at the end of
each operating-day, or at more frequent
intervals, if necessary, to control disease
vectors, fires, odors, blowing litter, and
scavenging. MSWLFs receive wastes:
that consist of a wide variety of
materials. In particular, such facilities '
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
receive wastes that contain putrescible
materials. As discussed in the -
background document for this section of
the proposal (Ref. 3], the disposal of
such materials in MSWLFs results in
conditions conducive to the harborage
of rodents and other disease vectors.
EPA is proposing this requirement
because problems associated with
putrescible waste at MSWLFs are
alleviated in part by cover material. In
addition, 45 States and Territories
require daily cover, suggesting that this
is an effective procedure and that, by
not requiring daily cover, the current
Criteria are not sufficient.
Cover material serves several specific
purposes for protecting human health
and the environment: (1) It helps in
disease vector and rodent control; [2] it
helps contain odor, litter, and air
emissions, which may threaten human
health and environment and/or be
aesthetically displeasing; (3) it lessens
the risk and spread of fires; and f4) it
reduces infiltration of rainwater by
increasing run-off and thereby decreases
leachate generation and surface and
ground-water contamination. As an
additional benefit, cover enhances the
site appearance and utilization after
completion.
EPA has not specified the type or
amount of cover material to be used,
leaving the determination of "suitable
material" and minimum depth up to the
State; however, EPA recommends that a
six-inch depth of compacted earthen
material be used as cover material.
Tests have shown that 8 inches of
compacted sandy loam prevent fly
emergence! daily (or more frequent)
cover has been shown to reduce the
attraction of birds and to discourage
rodents from burrowing into the waste.
In addition, 45 States and Territories •
already specifically require 6 inches of
daily cover and it is considered an
accepted practice at most MSWLFs.
This and other aspects of cover material
are discussed in the background
document for this section (Ref. 3).
Today's proposal allows the States to
temporarily waive the daily cover
requirement on a case-by-case basis in
the event of extreme seasonal climate
conditions, such as heavy snow or
severe freezing, that make meeting the
requirement impractical. This provision
would allow the State to consider the
practicable capability of the regulated
community. EPA requests comments on
the appropriateness of the frequency
and depth of cover application and on
whether there are other reasons for
exempting daily cover. EPA also is
requesting comments on the
acceptability of cover materials other
than earthen materials (e.g., foams).
3. Section 258.22 Disease Vector Control
Today's proposal would require that
each owner or operator of an MSWLF
prevent or control on-site disease vector
populations using appropriate
techniques to protect human health and
the environment. This requirement is
consistent with existing § 257.3-6, which
states that "[t]he facility or practice
shall not exist or occur unless the on-
site population of disease vectors is
minimized through the periodic
application of cover material or other
techniques as appropriate so as to
protect public health."
Municipal wastes are known to
contain pathogenic bacteria, parasites,
and viruses that can infect humans and
animals. These wastes also provide food
and harborage from rodents, flies, and
mosquitoes that then transmit disease
organisms to humans and animals.
The performance criterion set forth in
this section would provide States and
MSWLF owners and operators
flexibility in meeting this requirement to
accommodate site-specific differences in
vectors and in appropriate control
technologies and mechanisms. Today's
proposed standard to control disease
vectors is intended to prevent the
facility from being a breeding ground,
habitat, or a feeding area for disease
vector populations. The requirements for
vector control are to be undertaken in
conjunction with the cover material
requirements in § 258.21. Cover material
applied at the end of each operating day
reduces the availability of food and
harborage for rodents and other vectors
and thus may be adequate in most cases
to meet the performance criterion for
disease vector control; however, if cover
material requirements prove insufficient
to ensure vector control, this criterion
would require that other steps be taken
by the owner or operator to ensure such
control. The background document for
this section discusses various methods
for minimizing disease vectors (Ref. 3).
4. Section 258.23 Explosive Gases
Control
The decomposition of solid waste (in
particular, household waste) produces
methane, an explosive gas. The
accumulation of methane gas in MSWLF
structures or nearby off-site structures
can result in fire and explosions,
potentially injuring or killing employees,
users of the disposal site, and occupants
of nearby structures, in addition to
damaging containment structures
resulting in the emission of toxic fumes.
Several incidents resulting in deaths are
discussed in the background document
(Ref. 3).
For this reason, EPA established an
explosive gas criterion in § 257.3-8 of
the original Subtitle D Criteria to
regulate the concentration of methane in
facility structures and at the property
boundary. This requirement is expanded
in today's proposal. The lower explosive
limit (LEL) of a gas is lie lowest percent,
by volume, of that gas in a mixture of
explosive gases that will propagate a
flame in air at 25°C and atmospheric
pressure at sea level. Today's proposal
would require that the concentration of
methane generated by the MSWLFs not
exceed 25 percent of the T.RTi in facility
structures (excluding gas control or
recovery system components): and the
LEL itself at the property boundary. EPA
based its selection of the 25 percent
figure for the Criteria on a safety factor
recognized by other Federal agencies as
being appropriate for similar situations
(Ref. 3); however, the Agency concluded
that a 25 percent criterion was
unnecessary at the property boundary
because gases at or below the T.RT. at the
property boundary will become
'somewhat diffused before passing into a
structure beyond th6 property boundary.
For these reasons, EPA continues to
believe that the LEL standard would
provide an adequate safety margin
against off-site explosions. The Agency
believes that these limits are protective
of human health and the environment
while not being unduly restrictive.
Further, the proposal includes routine
subsurface and facility structure gas
monitoring requirements and a
requirement that, if methane exceeds the
limits specified, the owner or operator
must take necessary steps to ensure ,
protection of human health and
immediately notify the State of the level
detected and the steps taken to protect
human health. Such steps could include
evacuation and ventilation of affected
buildings. In addition, the Agency is
proposing that the owner or operator
submit a remediation plan to the State
within 14 days of limits having been
exceeded. This remediation plan must
describe the nature and extent of the
problem and the proposed remedy.
Examples of appropriate remedies
include installation of interceptor gas
collection trenches, venting in
structures, and subsurface gas
withdrawal. The owner or operator
would be required to implement the plan
after State approval.
In reviewing damage cases that have
occurred as a result of methane
migration from landfills, the Agency has
noted that many of these incidents have
occurred since promulgation in 1979 of
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Eedeiral Register / Wol.
- tL69, Toe sdajr,
rosd
tei ekistiiig-uCriteiia,
tre.quire 'routine ,gas monitoring. .The
Agency ibelieves many of these
mstances'could:have been prevented if
routine monitoring had been conducted
'toidetectrthe.dangerQus-levelsjprior to
the incident. This tissue is further ,
discussed in the background document
(Ref. 3). Early warning -would allowihe
owner or qperatorito take action to
prevent catastrqphic^vents.
[Because Lmethanerhas'been the
principaLsouree of'fijcplosions
associated with solid waste disposal,
ERA proposes .to require monitoring only
forimeihane at this .time. EPAjmay
require monitoring forrother.gases if new
mformation:de.velqps at,alater time
indicating that Jhere are other gases that
pose problems; however, EPA currently
does not have sufficient information on
Other gases generated to justify requiring
owners and operators to jnonitor lor
.them.
;;EPA isEpropos'ing'tha't methane,
monitoring be conducted atkast
quarterly. As smerifioned earlier,
monitoring would provide early warning
,of .potential methane build-up that may
lead to explosions.'The Agency'believes
that quarterly monitoring is,a
•reasonable mininium.irequency'that
"accounts for'the seasonal'variationBin
s.ubsurface;gas migration patterns.'The
Agency recognizes -that site-specific
conditions may 'require more frequerit
monitoring, e;g;,"when-facilities areTiear
residential areas or enclosed in
structures,'and-encourages'States to
require additional monitoring 'as
necessary/There also -may 'Delimited
.situations (Big., in very-remote areas)
where less "frequent monitoring may :be
-Sufficient. «EPA requests -comment on- •
these simafionsand'the appropriateness
• of the "minimum inonitdfing'rrequency
specified in toSayls proposal.
Monitoringiis"intended to-ensure'that
the pBrformanGe standard is toeing met
atfthe MSWEE-iEPA'Considered
specifying'the itype of .monitoring and
monitoring;deviGes, but suchsan
-approadh would no't.allowithe,
consideration of-site-'Specificifactors'in
^establishing !the appropriateimonitormg
system. The proposal would allow State
Jlexibilityon-determining the appropriate
monitoring requirements on a case-byv
case basis.
Site-specific factors to :te considered
when determining .the rtypesand
frequency f of:monitorang are tdiscussed.'in
•an Agency-guidanceymanual (Rfif. 12].
JKactnrs*,to ;be :corisidered:in;jde±ermiriing
the ^qpeoand frequency •nfmonitarfng
include:-:soil conditiQns,,hydrjpgeolpgic
(conditions surro.unding"thE"di;Eiposal site,
hydraulic conditions tsurrounding :the
iiis.posal site, and ihe locatiomoMacility
structures and relative to [property
boundaries, These'factors :control;the
rate and extent•_of ;gas migration;and are
discusseddfurther.inithe.guidancB
.manual (Ref.,12J.
:Mordtoring.in a-facility rstructure
jiormally should be;performed after'the
buildingias been closed overnight or
for;a weekendibecause'theserare the
tunes when She most'dangerous
conditions arelikelyito exist..Sampling
should bs done in confined areas;where
;.gas may accumulate, such as in
basements, crawl spaces, attics near
floor cracks,'find ground subaurface
utility iConnectians.'.Gas recovery and ,
gas control equipment, :however, need
notibe sampled. If allshejceadings -are
less than.J25rpercentLEL, the MSWLF
would be ;in,compliance; .-however, the
presence of anymBthane in afacility
'structure, i even in'.concentratioHs below
25 percent LEL, shouldlbe considered a
problem that xleseEVfis rstttention and
step.s;;should be'takenlo'-ensure that':the
level tifanethane does noisreach
explosivelewels. EPAiEecommends that
continuousrmonitoring devices-be used
in facUityBtmctures at the landfill isite.
For.mbnitoringaldngrprpperty .
'haundaries., atleast .two monitoring
points shoukLbe located along "the
;prqperty:boundaries''closestito
residences orcother .potentially affected
structures. The jexact location t)f these
po'intS'.^houldotakejintoiaccount anygas-
permeable seams. In selecting the
saniplingjiomls, someof the factors .to
consider include dry sand or gravel '•
:pockets, .alignment with an nffesite point
of concern, proximity cf ahesvaste
deposit, -areas .where ;there is dead nf
urihealfliy vegetationTthataniightibe .due
to gas migration, and areas sphere
underground.Gonstructionjnayimve
crfialeda natural 3)ath?for;gas2flowfB:g.,
utility lines). •
MonitaringiBhould be iconductedjatithe
propfirtyiouridaries'Meallyiwhen.thB
soil surfaGB.has faeen wet -or frozen fer
several daysieGause this is-when levels
are expected.tbEbejgBeatest'fRef. 12). Tie
results, location, date, sand time nf
fmnnitoring.should:bea:ecorded. Jf :any pf
thBiTeadingsare Equal io ur.igEeater»than
the LEL, the facility would not be in
xomplianGe.fltanayiae necessary to
repeat the tests atalaterdate nr jnider,
different idimatic jconditions to iverify
' the leadings. Whers active rcnntrol
systems,are:faeingused, samples should
be takenTwhen allipumps.haye^beBnishut
downsfor their maximum lime during
-normal operation.
tMonitoring at the.proper tyimimdary
could ^accomplished bysusing a
;permanent'wellfora;portablejmonitoring
device. The-devicershould be
determined'.byi.the'State ona case-by-
xaseibasis^EPAihastprovidedadditional
guidaacecon-types ofimonitoringtdeviees
'thatieould be .usedfpef.:12). The Agency
suggests ithatmethane ata
CDnceiitrationj'ust below the iliEL at a
^monitoring .point 'may indicate a major
problism aiid.should/not be ignored. Mie
appropriate action • would-depend on -the
proxiimtyfflfrxiff-site'Structur.es.ipossible
.pathways, and other factors. -In -a]l
.cases, an5evaluation should/be made'so
tthat tliecdanger ofifixplosion.ds
minimized.
5! Section 258:24' Air Criteria
The existing;Griteria.'in Part 257
prahiljit ?the >openiurmivg' of 'solid swas.te
but allow infrequent tburningtof
cagriciiitural iwastes, isiivicultural wastes,
land.iilearingidebris, diseasedtrees,
debriHtfromtemErgency cleanup
.operations, and ordnance."irodayJs
standard. iRequirements ,f orrGompliance
with State Implementation .Plans (SIKsJ
under ^sectionMO of the 'Clean Air jAct
(CAAJ .would,remain unchanged ;Jrom
the Part»257 Griteriar
The Agency believes thatany
infrec[uent bjurnmgfof the -waste types ;
listed-above should be conducted sin
areas dedicated for [timtpurposeand'at
a distance awayrfronicthe'landfilliunit so
as to preclude ithe accidentaliburning nf
•.other^olid -waste. -Fortthe jiurposes'of
thisjprqposal.agriciilturaliwaste.does
not mclude emptypesticide containers
or .warSte pesticides.
OpjenrTiurriing, which.is !the
uncontrolledirorrunconfinedrcombustion
of solid wastes, is a potehtialihealth
hazard, idamages .property, and-.can:be -; a
..thretft to .public safety. sFor. example,
smoke [from lOpeniburnujg ;can jeduce
ah'crEfft and automobile visibility , and
has beenlinked to au'tomobile accidents
and dfiath-on-exprfissways. Theair
emissions assooiBtted with.openfburning
aretm.ucih'higher than -those associated
wi thincinera tors equippedjwith air
pollution control devices. .Combustion in
a taBrLch'.orspitdncineratcir.is considered
thecesjuivalent jof flpen burning because
particiulate emissions ;from trench and •
pit iniainerators equai-or-exceedrthose
from iqpen 'burning.
As'Stated.eaflier, EPA^originally ;
established me 'ban ton'qpeiiiburriiijgiin
the dtJ)79fGrlteria. :Gommenters onithe
lpr,opcisaLto'.thei979 Criteria 'questioned
•the necessity .for .that ban, «.tatingahat
open.buriiing jeduces the .volumerof
solid waste and helps -control disease
(Vectors. The Agency jecognizedthat
' someljvolumerreduction,is.achieved,ibut
Hodata were ^provided that >disease
vectors were sjgnificantly.Tfiduced. EPA
estafalishBd'the^ari'ori qpentburning of
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Federal Register / Vol. 53, No. 168, Tuesday; August 30, 1988 / Proposed Rules
these wastes because the hazards posed
to human health (e.g., increase in
pnrticulate emissions, decreased safety)
outweighed any benefits derived from
the practice. Since the promulgation of
the current Part 257 Criteria, the Agency
has not received any new data that
would contradict this conclusion.
Therefore, EPA is retaining the open
burning prohibition in today's proposal.
The Agency is aware that some States
allow certain communities to open burn
routinely municipal solid waste under
certain circumstances. Such
communities usually generate small
amounts of waste and are in remote
areas. The major advantage claimed is
substantial volume reduction in the
waste to be disposed of, thus extending
landfill life. These communities assert
that disposal costs would increase
dramatically if there were strict
enforcement of the Federal ban on open
burning; however, these communities
have not addressed the impacts on
human health and the environment
resulting from the practice on open
burning, and, because health and
environmental concerns are the
underlying reason for the ban, the
Agency does not intend to change the
requirement from the 1979 Criteria.
However, because EPA has received
these comments stating that open
burning is a necessary disposal practice,
the Agency is specifically requesting
comment on this issue.
This proposal retains the requirement
that new and existing MSWLFs not
violate applicable requirements
developed under a SIP approved or
promulgated by the Administrator under
the CAA Section 110, as amended. EPA
originally instituted this requirement
because regional health concerns
addressed through the SJPs clearly are
of concern under RCRA as well as the
CAA. Obviously, RCRA regulations
should not undermine the provisions
that implement the CAA.
Recent studies conducted by the
Agency indicate that MSWLFs also
appear to be a source of air pollutants.
Gases of decomposition originate within
the landfill and vent to the atmosphere
by vertical migration and/or lateral
migration. Landfill gas is generated by
chemical reactions and by microbial
degradation of refuse materials into a
variety of simpler compounds. Typically,
landfill gas consists of approximately 50
percent methane, 50 percent carbon
dioxide, and trace consu'tutents of
volatile organic compounds (VOCs) and
other toxic constituents. Pollutants
commonly found in MSWLF gas include
vinyl chloride, benzene,
trichloroethylene, and methylene
chloride. It is estimated that
approximately 200,000 metric tons of
nonmethane organics per year are
emitted nationwide from existing
MSWLFs. Some of these compounds can
create an odor nuisance while the VOCs
and other toxic emissions can constitute
a health hazard. This is in addition to
the dangers from the explosion potential
of methane (as described above).
Air emissions from MSWLFs can be
controlled by collecting and controlling
(or recovering) the extracted landfill gas.
At approximately 100 landfills, gas is
collected and used as recovered energy.
Control systems can be economically
attractive due to the energy recovery
benefits, especially at larger landfills.
There are sites controlling or recovering
landfill gas in many States, including
California, Maryland, New Jersey, New
York, Ohio, Oregon, Texas, Wisconsin,
and Washington.
EPA has decided to regulate MSWLF
air emissions under the CAA Section
lll(b) for new landfills and Section
lll(d) for existing landfills. Under
Section lll(d), EPA is preparing ait
emission guidelines that are to be.
adopted by States; they will prepare
plans for controlling existing sources of
MSWLF air emissions according to the
EPA guidelines. The regulations will be
based on both collecting and controlling
landfill gas. EPA plans to propose air
emission standards for MSWLFs in the
near future.
6. Section 258.25 Access Requirements
EPA is proposing to require control of
public access at new and existing
MSWLFs to prevent illegal dumping of .
wastes and public exposure to hazards
at MSWLFs as well as to prevent
unauthorized vehicular traffic. Access
control is a key element in preventing
injury or death at these facilities.
Because EPA also is concerned with the
unauthorized dumping of hazardous
waste, the proposed requirement
expands on the existing 257.3-8 health
and safety criteria, which prohibit
uncontrolled public access, by adding
requirements to control illegal dumping
of wastes and unauthorized vehicular
traffic.
EPA proposes that MSWLF owners or
operators control public access, illegal
dumping, and unauthorized vehicular
traffic using natural and/or artificial
barriers, as appropriate, to protect
human health and the environment.
Steps needed to comply with this
standard would be determined by the
State on a site-specific basis. At some
facilities, it may not be necessary to
construct any artificial barriers, such as
fences, in order to comply with this
criterion. Such facilities include, for
example, those located, in remote areas
away from the general public or in areas
with mountainous terrain or cliffs that
would make access by the general
public difficult. Posting signs and gates
across access roads may be sufficient in
remote areas to prevent public access
that could lead to injuries; however,
facilities that are located near
residential areas or other public areas
may be required to construct fences in
order to control access. Unauthorized
vehicular traffic and illegal dumping
could be prevented by placing gates
with locks at all entrances to a remote
site. Other provisions may be necessary
on a site-by-site basis.
Under the Subtitle C regulations, the
owner or operator must prevent
unknowing entry, and minimize the
possibility for unauthorized entry, onto
the active portions of the facility. At a
minimum, a hazardous waste facility
must have a 24-hour surveillance system
or an artificial or natural barrier, such as
a fence hi good repair or a fence in
combination with a cliff that completely
surrounds the active portion of the
facility, and a means to control entry at
all times. The requirements may be
waived under Subtitle C if it can be
demonstrated that physical contact with
the waste or equipment will not injure
unauthorized persons or livestock and
disturbance of the waste or equipment
will not threaten human health and the
environment.
These Subtitle C requirements are
considered unnecessary for MSWLFs
because EPA believes the risks
associated with direct contact with
municipal solid wastes are less than
those associated with hazardous waste.
Today's proposal allows greater
consideration of site-specific conditions
in establishing the appropriate controls
than the Subtitle C regulations do. For
example, as discussed above, the
remoteness of a site may serve as an
adequate "natural barrier" to facility
access. EPA believes that simply
requiring owners or operators to control
public access allows the owner or
operator to implement a system tailored
to site-specific characteristics.
7. Section 258.26 Run-on/Runoff Control
Systems
EPA is proposing run-on and run-off
control requirements. These
requirements are interrelated in that
diversion of run-on reduces the amount
of run-off that needs to be collected. The
proposal would require that the owner
or operator of an MSWLF design,
construct, and maintain a run-on control
system to prevent flow onto the active
portion of the MSWLF during the peak
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August. 30, ,1988 / .rPrqposed -Rules
J33S39
discharge of a 25-year.:storm. The,
purpose of the ;run-on standard as to
minimize .the ;arnount -of surface water
entering the landfill facility. -Run-on ;
controls prevent: {1) Erosion, which may
damage the physical structure of the
.landfill (2) the .surface discharge , of
wastes in salutionrdr suspension, -and (3)
the downward percolation of jun-on
through-wastes, .creating leachate,
Control is : accomplished .by constructing
diversionistnictures to prevent surface
water ;run-im,from. entering the active
portion of fee Iacility.;Diversion
istructures^he'lp piavent, liquids, which ". -
wlll.eventuaily generate 'leachate , or
leave the.site.as. contaminated run-off,
from coming into contact with the
.waste.
The Agenpy believes that fee main
apearofjcojicern,"withsrespect to run-on,
ds .the active .portion.pf the [landfill, -not
the landfill facility as a whole. In this
proposal, -that part cf fee facility or .unit
thathas received or Is receiving wastes
and has not.been.closed as -required in
§ 258.30 is defined as the active portion.
Ittis.at , active jportions that run-on is
mostlikelyto: (1) Seep into the;exposed
waste, contributing to;thedformation:of
leachate, or [2] erode wastes, or
constituents':of them, anddcarry them
away in surface water jmHoff. Seepage
and erosion _w.ouldtnot be ,a .problem at
inactive portions that .have been closed
in JaccoroWce wife ihe closure Criteria
speciBea in ;§ ,258.30. The Agency
.proposes ihat- surface water, run-on be
,diverted:from«active portions. -Diversion
of run-on may , be accomplished by
locating fee active portion in areas -
where the .topography jiaturallyoprevents
run-on, by sloping or contouring .the
, land, or, by constructing ditches,
: culverts, , or dikes. Ihe capacity of
diversion structures should be .
determinedl>y .the owner or operator
considering site topography, size of .the
dramage,area, and sizetof ihe .active
portions. The Agency chose the 25-year
storm as fhe;design:pafameter to be
consistent wlfe.fee standard jn 40 CFR
Eart,:26S, whichjequires active .portions
ofhazardous wastelandfills to.be
.protected^om fee peak discharge of.a
The -quantity of run-off from-active
portions of landfills can -be^minimized
by (1) minimizingoiin-on, (2) preventing
disposal oJh'guid wastesan ,the landflll,
and (3) minimiziijgcthe size of ithe^active
portion of .the landfill. Tp=address run-
,off fthat isjgenerated, -the iAgency
proposes to require -thatrthe owner-or
operator of an MSWLF design,
constnict.rand mainta'iri>a runroff. control
system from fee active portion ;of tthe
landfill ,to;collect .and-control atleast .the
water volume resulting from a 24-Jtour,
25-year storm. Run-off from ;the active
portion ofitheiinit must bejiandled iii
accordance :with:| 258.27:of this • .•
proposal in order to ensure.that the
CWA NEDES:requirements and GWA
Section 208 and.319 requirements are
not violatedwAgain,-the .Agency chose
the-24-Jiour,;257year,s.tormdesign
parameter tote consistent with the
standards for.Subtitle C iacilities.'in i40
. CFR,Eart.264.
"By design, almost alLtrench»and area
fills in.degressions or pits contrtiLmost
run^off "because of'surface .contours;
Owners and operators having.area fills
that do,not use depressions can.coritrol
run-offty building a berm or dike on the
low elevation side; however, when
landfills.using either the .trench OT.area
methods become large or substantially
above grade, both runoff and leachate
seeps, which often occur on fee-outer
•slopes of fee fill,,need to be collected.
Run-off that does emerg from active
portions may;be collected:by ditches),
berms, 'dikes, or culverts, which dkect it
(sometimes'by sumpjpump') tdsurface.
impoundments,:basins, tanks, or
treatment: facilities. These cdllection
devices may consist of'teniporary "•
•structures'around active portion's.
because-ron-tjff usually has been in
contact wife waste or leachete seeps
from active portions and sometimes is
collected via a leachate collection
system, it probably will-foe
contaminated. It;is "difficult'to
differentiate ^between rainwalter run-*>ff
and'leachate irun.-o'ff at-fee active
portion of alandfill;unless an slaborate
or expensive ssampling program is
conducted. Once;collected,ia;number;'of
options.exisffcir treating and disposing
of run-off/Thesefinclude land treatment,
treatment hi surface impoundments^eig.,
evaporatiori), or- discharge to a sewer, •
ofeer treatment facility.'or surface
watersipf permitted).The>background'
doeument :supportmg this section .of-the
rule'^Ref.' 3) discusses in fuffeer detail
25-year storm events -and Tun-on -and
run^off contrdl requirements..
B, Section 258.27 Surface Water
Hequiremerits
Today's proposal .wjould prohibit any
MSWU1 unit from (4) causfaig a -
discharge rof;pollutarits into waters of
fee U.S., including wetlands, feat
violates any'requirements of fee CWA,
including,-but notilimited tq.TMEDES
requiremeiits; andi (2) causing a.nonpoint
source of polution to fee waters of [fee
U.S., including wetlands, feat violates
any 'requirements nf. a State-wide or
area-wide swater quah'ty jnanagement
plan under Section 208 or Section 319 ol
fee GWA. The.aurfkce water-criterion
curreiatly in'JPart:257 wasiretainedtin
today''srpr;qposalibecause EPA believes
-it tproirides necessary .pro'tection;fDr
hurnan.heaith .arid the environment.
• EPA;CQnsiders:it'essential that, solid :
waste activitiesrnotiadversely affect .the
gualijiy of ihe ^nation's-surface waters.
fRiv.ejCS,.lakes, andr streams are important
sourqps of drinking .water,-recreational
resources,.ahd habitat for a wide-variety
-offish wife other aquatic organisms.
: Solid Waste disposal has led to .-surf ace
water contamination'from run-off .of
leachate,, accidential spills, arid .drift .of
spray occurririg at landfills. In ,fee
proposed Criteria, EPA seeks .to ' -
coordinate dts surface water ". '.
requirements under^RCRA,.including
programs-developed under ihe CM/A to
resto]rfi,and.mairitain»fee,uitegrity:of fee
waters ,6fihe United&ates.
Umller Section 1006 otRCRA, EPA is
requited to'mtegrate,.to fee maximum
exterji.practicable, fee provisions of
RCR& with dther.statutes,'includhig the
CW^.rUnderrfee"CWA, EPA conducts
programs designed'"to restore and -
mainltain'fee chemical, physical, and
biplogicaiaritegrity;dfihe.nation's
water.'VEPA believes-feat thisvgoal also
;isa!l(!gitimate objective forits
reguliitoryactM^r under RCRA and, feat
fee Agency;shoulduselts authority
.undeir^RCRAtosee feat "CWA goals are
'achieved. Tiius, in establishmg the
surface water criteria, EPA 'employed
concepts and approaches use unfler the
CWA. The discharge-'of a nonppint
source of-pollvitidn from solid-waste
disposal^ctivities wouldi be required to -
conform wifeiany*es'tablished water
qualiltyriianagemeiit plan'developed
undercSeCtioh:208 or-Section 319idf the
CWA. Not all portions of a;SectHur208
or Seiction,319;plan are applicable to
solid iwaste,disposaLactivities,;andihe
State,: would;determhie which
requiremerits under these plans apply.
Similarly, ifeeidischaEgerpf pollutants
from solid waste disposal activities
wouldtbe trequired Jo; comply swifecofeer
iprovisions of;the GWA, .includingcfee
NPDES reguirements under Bection;402.
Tihi3:provision df ii257.3-3::offfee
current Criteria, which states ifeat '*a
JfaciliJlyshalhnDt.Eauseia dischargecdf
dredgied.materialror filLmaterral 'to
wa'teis!oftfee UnitedStatesihatiisdn
violaltioniof fee: requirements (under
Section-4D4'Of CWA, fas amended," thas
beeniincludedrunder the wetlands
sectionrfitpday's propDsed:Parti258
Criteria., ; ..-.--
9. Secition 258.28 Liquids Restrictions
•EPA'is proposirig;a riewacequirement
foriliquids restrictions because ?fee
inten iojiallijtepduction of liquids into
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33310 Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Prbp&slid'Ruigii
landfills can be a significant source of
leachate generation. Today's proposal
would prohibit bulk or noncontainerized
liquid waste that are not household
waste (other than septic waste) from
being disposed of in MSWLFs. Leachate
and gas condensate that is derived from
the MSWLF unit and recirculated would
be exempt from this prohibition if the
unit has been equipped with a
composite liner and a leachate
collection system designed and
constructed to maintain less than 30cm
of leachate over the liner in order to
ensure that the recirculated liquids are
managed properly. Containers of liquid
waste could bo placed in MSWLFs only
when the containers: (1) Are small
containers of the size typically found in
household waste, (2) are designed to
hold liquids for use other than storage,
auch as a battery or capacitor, or (3)
hold household waste.
By restricting the introduction of
liquids into !a,ndfills through a ban on
the disposal of bulk and containerized
liquid waste, EPA expacts to minimize
the leachate generation potential of the
landfills, and thus minimize the risk of
gound-water contamination. Twenty-one
States and Territories already prohibit
disposal of liquids and semiliquid
wastes in MSWLFs. EPA believes,
therefore, that this restriction is a sound
MSWLF management practice.
The problems associated with the
landfill disposal of containerized liquid
wastes arise upon the eventual
deterioration of the waste container.
Liquids escaping from leaking
containers will migrate to the bottom of
the landfill, acting as a transport and
leaching medium for the wastes
contained in the landfill. Liquids
accumulating on landfill liners can
contribute to liner failure through
increased hydraulic pressure and/or
chemical interactions. Increased
hydraulic head due to liquid
accumulation can increase the amount
and rate of contaminant movement from
the landfill to the ground water.
Additionally, when waste containers
degrade, allowing their contents to
escape, they collapse under the pressure
of the landfill. This situation can create
voids in the landfill, which can lead to
slumping and subsidence of the final
cover. Ones the integrity of the landfill
cover is lost, infiltration of precipitation
will increase, contributing to the
leachate generation in the landfill.
Collapse of deteriorated waste
containers and subsequent damage to
the cover material could occur after the
post-closure care period of the landfill,
when ground-water monitoring systems
are not maintained to detect ground-
water contamination.
Disposal of bulk or noncontainerized
liquids in landfills present the same
problems that disposal of containerized
liquids present once they have leaked
from this containers, namely, increased
mobility of wastes in the landfill,
increased risk of loss of liner integrity
through greater pressure and/or
chemical interactions, and increased
hydraulic head, which can increase the
rate and quantity of movement of
contaminants to the ground water.
EPA believes that the proposed ban
on the disposal of bulk or
noncontainerized liquids (except
nonseptic waste from households and
recirculated leachate and gas
condensate at facilities with specific
designs) will greatly reduce the quantity
of free liquids to be managed in
MSWLFs, which, in turn, will reduce the
risk of liner failure and subsequent
contamination of the ground water. The
ban on containerized free liquids
(except those from households) will
achieve the same purposes as the ban
on bulk liquids, and, in addition, will
reduce the problem of subsidence and
possible damage to the final cover upon
eventual deterioration of the waste
containers.
EPA recognizes that landfills are, in
effect, biological systems that require
moisture for decomposition to occur and
that this moisture promotes
decomposition of the wastes and
stabilization of the landfill. Therefore,
adding liquids may promote
stabilization of the unit. Some concern
has been expressed that the Agency
requirements would effectively place
landfills in a state of "suspended
animation," impeding stabilization by
minimizing introduction of liquids. EPA
does not agree with this argument for
several reasons. .Wastes received at
landfills already contain moisture (10
percent to 35 percent by volume). The ,
Agency believes that this moisture is
sufficient for decomposition to proceed.
In addition, moisture is added from
rainfall, and more moisture is generated
during the decomposition process.
Finally, although the Agency recognizes
that moisture is necessary for waste
decomposition, it does not have data
that indicate that allowing the
deliberate introduction of liquids into a
unit for stabilization purposes is
beneficial and outweighs the potential
problems incurred from increased
volumes of leachate.
The intent of today's proposal is to
prohibit the disposal of bulk or
noncontainerized liquid waste at new
and existing MSWLFs units. Household
waste (other than septic waste) is
exempted because it is beyond the
practicable capability of owners and
operators to effectively restrict the
disposal of all household liquid waste.
Furthermore, the primary purpose of •
today's liquids restrictions is to limit the
disposal of large-volume liquids in the
landfill. Septic wastes would not be
exempted because they are easily
identifiable and restricted if they do not
pass the liquids test described below.
Certain small containers (e.g., paint .
cans) and other wastes (e.g., batteries)
would be exempt from the containerized
liquids ban because they are not likely
to contribute substantial amounts of
liquids at most landfills and the
difficulty of opening and emptying them
appears to outweigh the small benefit
gained (Ref. 3). EPA believes that the 18-
month period between the promulgation
date and the effective date of the rule
would allow liquid waste disposers
adequate time to develop alternatives to
liquids disposal in MSWLFs. .
Under this proposal, the owner or
operator would be required to determine
if wastes (e.g., septic wastes, municipal
wastewater sludge) are liquid waste by
using the Paint Filter Liquids Test
method. This test method (Method 9095)
already has been adopted by the ,
Subtitle C hazardous waste program
(Ref. 34). As discussed earlier under the
explanation for the proposed definition
for "liquid waste," the Agency requests
comments on the appropriateness of the
solids content measure as an alternative
to the Paint Filter Liquids Test for
POTW sludges for defining liquid waste.
The Agency is proposing to allow
leachate and gas condensate
recirculation at MSWLF units that
incorporate a composite liner and
leachate collection system into their
design. Studies have indicated that
leachate recirculation has certain
benefits, which include increasing the
rate of waste stabilization, improving
leachate quality, and increasing the
quantity and quality of methane gas
production. Leachate recirculation also
provides a viable on-site leachate
management method. Other methods for
managing leachate include disposal in
off-site POTWs or on-site treatment
facilities. These other methods,
however, may not be available or
practical because of limited POTW
capacity, institutional constraints, or
costs. Recent studies conducted by EPA
indicate that of those facilities collecting
leachate (481 MSWLFs or 5 percent of
total), 42 percent (205 MSWLFs) are
recirculating leachate. The Agency
expects that the number of MSWLFs
collecting leachate would increase with
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Tr Register/; ^pl. ,53; IjJp; il68,>;Ttiesday, August 3O, 1988 / «I'rpppsed Rules i 33341'
the implementation of today's proposed
design Criteria (Subpart D of today's
proposal).
.The Agency recognizes that there are
potential operational problems
associated with leachate and gas
condensate recirculation that may result
in adverse impacts on human health and
. the environment. These problems
include: (1) An increase in leachate
production, (2) clogging of the leachate
collection system. (LCS), (3) buildup of
hydraulic head within the unit (4) an
increase in air emissions and odor •
problems, and (5) an increase in-the
. potential of leachate polluant releases ,
due to drift and/or run-off. Therefore,
EPA is proposing that only MSWLF
units designed and equipped with
composite liners and an LGS
constructed to maintain less than a 30-
cm depth of leachate over the liner be
allowed to recirculate;leachate and gas
condensate.
A composite liner is a system
consisting of two components. The
upper component must contain a flexible
membrane liner (FML), and'the lower ',
component must contain at least a three-
foot layer of compacted soil with '
hydraulic conductivity of no more than
1X 10~7 centimeters per second. The
FML component must be installed in
direct and uniform contact,With the
compacted soil component so as to
minimize the migration of leachate
through the FML if a break should occurT
Because of the increased leachate
generation due to the increased amounts
of liquids and subsequent hydraulic
head buildup, EPA believes that the
added protection provided by a
composite liner is necessary to ensure
that contaminant migration to the
aquifer is controlled. First, ihe FML
portion of the liner will increase
leachate collection efficiency and
provide a more effective hydraulic
barrier. Second, the soil portion will
provide support for the FML and the
leachate collection system'and act as a
back-up in the event of failure of the
FML.
The standard for the LCS, i,e., the
requirement that it be constructed to
maintain less than 30 cm of leachate
over the liner, is the same standard
required for LCSs at Subtitle C
hazardous waste units, and various ,
technologies are available for meeting
this requirement (Ref. 3). The
appropriate technology depends on the
size of the unit, waste permeability, and
climatic conditions. LCS design
normally consists of a permeable
material placed on a sloping surface so
as to allow the leachate to be removed
and collected. For large units, a pipe •;
drainage system also may be necessary.-
" ; The Agency believes that, because of
the potential problems associated with
leachate recirculatipn discussed earlier,
the design requirements specified above •
generally are necessary to ensure -
protection of human health and the
environment; however, because the data
that EPA has collected on leachate ;
recirculation are limited to laboratory
studies (Ref. 24), the Agency is •
requesting aditional data on leachate
^recirculation, including pilot studies and
field data. ..;-..;;.; ;',-_'.
Prior to selecting today's proposed
approach, the Agency considered a wide
,range of options for leachate and gas :
condensate recirculation and is ,,
requesting comment On two additional •.'
options. EPA considered allowing
: waivers to the requirement that an-
MSWLF have a composite liner in order
to recirculate leachate. For example, the
waiver could be granted if the owner or
operator could demonstrate that: (1) The
unit is located over ground water that is
not a potential or current underground
"source of drinking water, and such
ground water is not interconnected to a
potential or current drinking water
source; or (2) recirculation of leachate or
gas condensate in the absence of a
composite liner or leachate collection ,
system would not result in •
contamination of ground water; or (3)
recirculation of leachate or gas
condensate hi,an existing unit not
equipped with a composite liner or ,
leachate collection system would pose
lower risks to human health and the
environment than disposal of this ,
leachate without recirculation.
Because of the previously mentioned" .
operational problems associated with
leachate and gas condensate
recirculation and the limited data
available, the Agency also is
considering a ban on leachate arid gas •••"-
condensate recirculation as an
alternative to today's proposal. Under
this alternative, for new MSWLF units,
the ban could be instituted on the
effective date of the revised Criteria and
could be!phased in for existing units
over a period of time, possibly five
years, to allow for alternative leachate
management practices to be
implemented. The Agency recognizes
• that the area of leachate and.gas
condensate recirculation will be
controversial and, therefore, is seeking
comment on a number of issues. The
Agency is seeking comment on the
appropriateness' of the proposed design
requirements and:whether other designs
would provide adequate protection, and
whether today's proposed requirement-
should; be modified to allow the State
greater flexibility in establishing ,
appropriate design controls. The Agency.
is requesting comment on the above, •.-
approaches to grantingrthe waivers and
is interested in receiving information on
- how to; develop the necessary waiver
demonstrations. Finally.'EPA is
specifically requesting •comments on
banning leachate and gas condensate
recirculation. • • , ;
10. Section 258.29 Recprdkeeping • ''.'•
Requirements • •
. EPA has included a recprdkeeping
requireiment in these proposed Criteria
. to ensiire that a historical record of
MSWIJF performance is maintained. The
pwner or operator would be-required to '
maintain the following records: Ground-
water monitoring, testing, or analytical.
data as specified under Subpart E of
today's proposal; gas monitoring results;
inspection records, training procedures, ;
and State notification procedures as
specified under § 258.20 of today's
proposial; and closure and post-closure
care plans required under proposed
§ § 258.30(b) and 258.31(c), respectively.
The required information would be,
recorded as it becomes available, and
maintained by the owner or operator of
new ahdexisting MSWLFs. This section
consolidates'the recordkeeping
requiriimerits of other sections of today's
proposial. ' • "• • - .-;.
; EPA believes that this requirement
would ensure the availability of basic
types of infoririation that demonstrates
compliance with today's requirements.
EPA hiis not defined tine time period for
retaining these records, required that
reports should be submitted, nor,
specified in what form records should be
maintained because the Agency believes
it is more appropriate for these : .
requirements to be specified by States,
which are directly responsible for
implehienting these provisions. EPA
believes this requirement is flexible
enough to allow the States 'to establish
specific requirements for recordkeeping
and to 'determine if additional records -
should be maintained.
11. Section 258.30 Closure Criteria :
• Because of the potentialthreats to
.human, health and the environment
posed by MSWLFs, the Agency believes
that is necessary to prescribe minimum
standards for closing these landfills.
Improperly closed landfills, as discussed
in a background document (Ref. 3), have
the potential for contaminating the - ..-':
enviro:pmeht due to inadequate controls
to conliain the wastes (e.g., a final cap
that erodes and fails to protect the • :
wastes! from being exposed). For this : .•
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / ProposedJRules1"
reason, the Agency is proposing criteria
for closure of MSWLFs in § 258.30 of
today's proposal to ensure that owners
and operators prevent threats to human
health and the environment caused by
improper landfill closure.
The closure criteria proposed today
specify a closure performance standard
that the owner of operator must meet
that will minimize the need for
maintenance after closure and minimize
the formation and release of leachate
and explosive gases during the post-
closure care period. Owners or
operators must prepare a closure plan,.
to be approved by the State, that
describes the activities to be undertaken
at the landfill to close it in accordance
with the closure performance standard.
Because prompt closure of a landfill is
important to minimize potential threats
to human health and the environment,
the Agency is proposing that closure
must begin promptly after the final
receipt of waste at each landfill unit. To
further ensure that closure is conducted
properly and in a timely manner, the
owner or operator also would be
required to submit a certification for
each unit at which closure had been
completed in accordance with the
closure plan. Other details regarding
closure (such as deadlines and
procedures foir submitting, approving,
and modifying closure plans; schedules
and deadlines for completing closure;
and other procedural requirements)
would be left to the States in order to
allow maximum flexibility without
compromising the intent of the closure
criteria,
a. Closure Performance Standard. The
closure performance standard proposed
by the Agency § 258.30(a) of today's rule
is designed to ensure that long-term
protection of human health and the
environment is achieved while providing
States with the flexibility to require
more specific technical closure
requirements. The Agency is proposing a
health-based performance standard for
the final cover, which is discussed in
Section IX. D of this preamble. States
are encouraged to specify technical
standards for satisfying the closure
performance standard (e.g., final cover
design and materials, cap permeability)
and may wish to refer to technical
guidance materials applicable to
Subtitle C hazardous waste facilities.
The components of the proposed
closure performance standard are
consistent with the closure performance
standard for Subtitle C hazardous waste
treatment, storage, and disposal
facilities. First, the MSWLF owner or
operator must close each landfill unit
(i.e., discrete cells or trenches in a
manner that minimizes the need for
further maintenance after operations
cease. Second, closure activities must
minimize the formation and release of
leachate and explosive gases after the
closure performance standard to the
extent necessary to protect human
health and the environment This dual
requirement establishes the standard for
the closure applicable to all MSWLFs
and, at the same time, allows owners or
operators and the States to determine
the site-specific technical requirements
necessary to achieve these general goals
of protecting human health and the
environment.
The Agency recognizes that many
owners and operators manage their
landfills in phases and close units (e.g.,
discret cells or trenches) as they are
filled. To ensure that the entire landfill
is closed in an environmentall sound
manner, the Agency is proposing that all
units of the landfill be closed in a
manner that satisfies the closure
performance standard, including units
closed prior to cessation of all
operations at the landfill. This
requirement also is consistent with the
Subtitle C requirements applicable to
hazardous waste facilities.
b. Closure Plan. To ensure that the
activities and resources necessary to
close MSWLFs in a way that will protect
human health and the environment have
been adequately considered, today's
proposed § 258.30(b) would require the
owner or operator of each new and
existing MSWLF to prepare a written
closure plan describing how all units of
the landfill will be closed in accordance
with the closure performance standard.
The closure plan also would serve as a
basis for enforcing the closure
performance standard and other closure
requirements under § 258.30. In addition,
this plan would serve as the basis for
determining site-specific cost estimates
and the amount of financial assurance
required under § 258.32. The proposed
requirement for a detailed written
closure plan is consistent with many
State solid waste regulations. A survey
of selected State programs indicated
that many States currently require the
owner or operator to demonstrate that it
has prepared for closure of the facility.
Section 258.30(b) of today's proposal
specifies the minimum information that
must be provided in the closure plan.
States are encouraged to supplement
these requirements to ensure more
complete and adequate closure plans.
States may wish to refer to the
regulatory and preamble language in 40
CFR Parts 264 and 265, Subpart G,
applicable to closure and post-closure
care standards for hazardous waste
facilities, for guidance in developing
more detailed closure plan
requirements.
Today's proposal specifies that the
closure plan must include (1) an overall
description of the methods, procedures,
and processes that will be used to close
each unit to the landfill in accordance
with the closure performance standard,
including procedures for
decontaminating the MSWLF, (2) an
estimate of the maximum extent of
operation that will be open during the
active life of the landfill, (3) an estimate
of the maximum inventory of wastes
ever on-site over the active life of the
landfill, (4) description of the final cover
designed in accordance with § 258.40(b]
and § 258.40(c), and (5) a schedule for
competing all activities necessary to
satisfy the closure performance
standard.
The closure plan should provide
enough detail to allow the State to
evaluate its adequacy. For example, the
description of the activities necessary to
complete all closure activities should
address removing, transporting, treating,
or disposing of any waste inventory
remaining at the landfill; monitoring the
ground-water and managing gas and
leachate during the closure period;
controlling run-on an run-off; and
decontaminating or removing
contaminated structures, equipment, and
soils. Decontamination procedures
include the methods for
decontaminating the MSWLF, sampling
and testing procedures, and criteria to
be used for evaluating contamination
levels. The estimate of the maximum
extent of operation of the landfill should
account for the largest portion of the
landfill ever open at any time over the
active life of the MSWLF. An area of a
landfill is considered open if it has not
been closed in accordance with the
technical closure requirements in
§§ 258.30 and 258.40 (i.e., final cover).
Therefore, areas that receive daily cover
but are not otherwise closed in
accordance with today's provisions
would be included in the estimate of the
maximum extent of operation. The
active life of the facility is defined in
§ 258.2 as the period from the initial
receipt of wastes until certification of
closure in accordance with the
requirements in § 258.30(e) has been
submitted and approved by the State.
The estimate of the maximum amount of
waste inventory ever handled at the
MSWLF at any time over the landfill's
active life should be included all wastes
awaiting landfilling as well as run-off in
trenches, ditches, or collection ponds.
The requirements to provide an estimate
of the maximum extent of landfill .
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•.Operation and an estimate of the
maximum amount of waste on site over
the active life of the landfill are .-'.'..-
important to accurately estimate the-
cost of closure, Financial assurance for
closure must be based oh the maximum
cost of closing the landfill based on site-
specific factors. Knowing the maximum
cost of closure ensures that adequate
funds for closure are available even if
closure takes place earlier than
expected, . .
The description of the final cover
should include the design of the final
coyer,'die types of materials to be used,
and how the final coyer will achieve the
objectives of the closure performance
standard. Filially, the closure schedule
.should include the total time required to
close each landfill unit and the time for
. mterverdng closure activities that will
allow the progress of closure to be
tracked (e.g., estimates of the time
required to decontaminate the MSWLF
and to place a final cover)i - ,
' Because today's rule applies only to
MSWLFs, the estimate'of the maximum
extent of operation, maximum amount of
inventory, and the corresponding
description of procedures for handling
these wastes refer only to those wastes •
and units that are integrally a part of the
operation of the MSWLF (e.g., run-off :
collection ponds). These regulations are.
not intended to address closure of other
structures or units at the facility that
may not be part of the landfill operation
(e.g., a surface impoundment used as -a -
sludge drying bed). : •'•'.'.
c,.Closure Plan Deadlineand
Approval. EPA is proposing in, :
§ 258.30(c) to require that the closure
plan be prepared as of the effective date
of the rule or by the initial receipt of ,
solid waste at the landfill, whichever is
later. Based on experience with
hazardous waste facilities under
Subtitle C, the Agency believes that the
proposed deadline for preparing the
closure plan is sufficient. A responsible
owner or operator already should have
considered many of the types of
activities required at closure as part of
routine operations, especially if--the
landfill is operated on a cell-by-cell
basis and cells are filled .and closed
successively. The owner or operator of
an existing MSWLF may be able to rely
- extensively on records of closure
activities of areas' no longer active in
preparing the plans (e.g., in developing* •
an appropriate final cover or in
determining the type qf final cover
used).
The Agency also is proposing in
. § 258.30(c) that the closure plan, and any
subsequent modifications to the plan,
must be approved by the State to ensure
that the plan adequately addresses all of
the required activities. This proposal is
particularly important because the
closure cost estimate and the amount of
financial responsibility required are,. .'
based directly oh the activities
described hi the closure plan. To allow
' the States maximum flexibility in-
developing procedures for implementing
these rules, the Agency is not proposing
specific deadlines and procedures for
submitting, approving, and modifying
closure plans. The Agency recognizes
that many States .already have approval
procedures in place, making specific
Federal requirements unnecessary and
potentially burdensome. For example,
most of the States surveyed approve
closure plans as part of the. permitting
process and requires that subsequent
modifications to the plans be subject to
State approval. Other States require that
owners or operators apply for closure
permits prior to closure. In developing ,
an approval process, States may wish to
review the procedures included in
Subpart G of 40 CFR Parts 264 and 265,
and the permitting requirements in 40
CFR Parts 124 and 270 that apply to
hazardous waste -facilities.
For recordkeeping purposes, the
Agency is proposing in § 258.30(c) that
the owner or operator maintain a copy
of the most recently approved closure
plan at the MSWLF facility, or at some
other place designated by the owner or
operator, until the "owner or operator has
been notified by the State that it has
been released from financial assurance
for closure of the entire landfill under
§258,32(f). •.-'.'
d. Triggers for Closure. To ensure that
MSWLF units are closed in a timely
manner after operations at the unit have
ceased and to protect against threats to
human health or the environment posed
by open but inactive landfills, the ;
Agency is proposing in § 258.30(d) that
the owner or operator begin closure
activities at each unit, in accordance
; with the approved closure plan, no later
than 30 days after the final receipt of
wastes at each landfill unit. Thus, if the
MSWLF is operated on an individual
.cell or trench basis, closure of each cell
or trench must begin within 30 days
following the final receipt of waste at
that unit. Extensions may-be granted at
- the discretion of the State, if the owner
or operator of the MSWLF demonstrates
that the open landfill unit _will not pose a
threat to human health or the
environment. These closure trigger
provisions in § 258.30(d) are consistent
with the closure trigger mechanisms for
hazardous waste facilities under
Subtitle C. States may wish to refer to
the language in 40 CFR Parts 264 and
265, Subpart G as guidance for •
developing more detailed provisions.
The Agency ^encourages States to . ;
define/'final receipt of wastes":to >
preclude MSWLF units from remaining '
inactive for an"indefinite period of time
"without closing. For example, States
may wish to adopt the provisions
applicable to hazardous waste facilities
that specify that closure of each unit
must beginno later than 30 days after
the final receipt of hazardous wastes, rip"
later than;one year after the most recent
receipt of hazardous wastes at that unit, i
Furthermore, States are encouraged to
establish specific criteria for granting
extensions of the deadline for, beginning
closure. For example, the Subtitle C
regulations for hazardous waste
r facilities specify that an extension,will
be granted only if the owner or operator,
demonstrates, among other
requirements, that (1) the facility .has "
remaiiiing capacity; arid (2) the:owner or
operator is operating m compliance with
all applicable regulations and will
continue to do so. •
As rioted above, the Agency is •
allowing the States to develop their own
procedural requirements, imcluding
provisions for owners or operators to
notify the States of their intent"to close
their landfill units. States are
encouraged to establish notificatidn
requirements that provide them with :
sufficient advance notice to inspect the ,
facility and to ensure that the approved;
closure plan,is still applicable to the .
facility's current conditions. States may •;
wish to adopt the notification provisions
included m the Subtitle C regulations
that reiquire advance notice prior to'•' '
closure of each unit of the landfill. If the
State allows the owner or operator to
gradually fund a trust fund as
demonstration of financial assurance,
notice of closure is particularly
important to ensure that the trust fund is
fully funded at,the:tme of closure. For
-- example, Subtitle C requires an estimate
of the expected year of closure, to be
included in the closure plan if the owner
or operator expects to'close the landfill •
prior to the end of the required trust
fund piay-in period.
Whiile today's proposal specifies -
when closure must begin, the Agency is
not proposing deadlines for completing
closure of an MSWLF unit. However, the
-; Agency is concerned that the completion
• of closure riot be delayed unnecessarily
, and is encouraging.States to specify
deadlines and interim milestones. For
example, the Subtitle C regulations for
hazardous waste facilities specify a six-
month, deadline for completing closure
and an interim milestone of, three
months for managing all inventory at the
site. Extensions to these deadlines may
be granted if (1) the closure activities
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333M Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Prbposed; Rules r
will take longer than six months to
complete or (2) there is a reasonable
likelihood that the owner or operator or
a person other than the owner or
operator will recommence operation of
the facility, the landfill has additional
capacity to receive waste, and closure
would be incompatible with continued
operation of the facility. In all cases, if
an extension for completing closure is
granted, the owner or operator of a
Subtitle C facility remains subject to all
applicable permit requirements and
must take all the necessary steps to
ensure protection of human health and
the environment The Agency requests
comment on the extent to which the
revised Criteria should specify
deadlines for completing closure.
0. Closure Certification. The Agency
is proposing in § 258.30{e) that following
closure of each MSWLF unit, the owner
or operator must submit to the State a
certification that closure of that unit has
been completed in accordance with the
approved closure plan. The closure
certification must objectively verify that
closure has been performed in
accordance with the closure
requirements, based on a review of the
landfill unit by a qualified party. State
approval of closure certification will
trigger the release of the owner and
operator from closure financial
responsibility requirements under
§ 258.32{f) (see Section 13.e below.)
The Agency is leaving to the
discretion of the State the types of
certifications that satisfy the
regulations; in all cases, however, the
certification must provide an objective
evaluation of site closure, based on a
direct review of the MSWLF unit by a
party qualified to make such an
assessment. Certifications that may
satisfy the criteria in today's proposal
include written verification by an
independent qualified party (e.g., an
independent registered professional
engineer) or a qualified in-house
registered professional engineer at the
MSWLF with knowledge about the
facility's operations who can objectively
evaluate the closure activities, or an on-
site review by State inspection officials.
While this certification requirement
allows the States more discretion than
under Subtitle C, the intent of today's
proposed rule is consistent with the
Subtitle C regulations, which require a
hazardous waste facility owner or
operator to submit a certification signed
by himself and an independent
registered professional engineer that
closure has been conducted in
accordance with the approved plan.
The Agency also is leaving to the
States 'he discretion to specify a •
deadline for submitting the certification.
States may wish to adopt the Subtitle C
regulations that require the certifications
to be submitted no later than 60 days
after the completion of closure of each
unit
12. Section 258.31 Post-Closure Care
Requirements
The closure performance standard
requires the owner or operator of an
MSWLF to close each landfill unit in a
manner that minimizes the need for
further maintenance and minimizes
leachate and gas formation. Even when
properly carried out, however, closure
cannot guarantee against long-term
environmental problems at landfills. For
this reason, the Agency is proposing that
the owner or operator conduct post-
closure monitoring and maintenance as
necessary to minimize future threats to
human health and the environment
following closure of each landfill unit.
The post-closure care requirements
proposed in § 258.31 of today's rule
specify the minimum activities
necessary to minimize deterioration of
the final cover and to detect problems
before they pose a threat to human
health and the environment. These
activities must be described in the post-
closure care plan under proposed
§ 258.31[c).
An owner or operator must begin
post-closure care activities following
closure of each landfill unit The Agency
is proposing that this post-closure care
period comprise two phases. In the first
phase, the owner or operator must
perform the post-closure care activities-
specified in § 258.31(a) for a minimum of
30 years; during the second phase, the
owner or operator must continue to
conduct certain post-closure care
activities specified in § 258.31(b). The
length of this second phase would be
specified by the State. The post-closure
care plan must describe the activities in
both phases of post-closure care.
a. Post-Closure Care Activities.
During the first 30 years of the post-
closure care period, the Agency is
proposing that the owner or operator
conduct routine maintenance of any
final cover, and continue any leachate
collection, ground-water monitoring, and
gas monitoring requirements as •
necessary to control the formation and
release of leachate and explosive gases
into the environment and maintain the
integrity of these monitoring systems.
Routine maintenance of the integrity
and effectiveness of the final cover,
proposed hi § 258.31(a)(l), is necessary
to prevent liquids from penetrating into
the closed landfill and creating the
potential for leachate migration.
Required activities include repairs to the
final cover to correct the effects of
settling, subsidence, erosion, or. other
events, and preventing run-on and run-
off from eroding or damaging the cover.
Cover maintenance also includes
periodic cap replacement, which is
necessary to remediate the effects of
routine deterioration. These activities
are intended to promote the Agency's
overall goal of minimizing liquids in
landfills and are the minimum steps the
Agency believes are necessary to
protect human health and the
environment in the long term. The
Agency believes that these requirements
also should provide an incentive to
properly manage solid wastes (e.g.,
ensuring proper compaction of wastes)
during the active life of the landfill.
The Agency is proposing in
§ 258.31(a)(2) that owners or operators
of MSWLFs designed with h'ner(s) and
leachate collection systems continue to
operate and maintain the leachate
collection system during the post-
closure care period in accordance with
the requirements of § 258.40(b).
Experience has shown that leachate
generation hi landfills continues long
after closure. Therefore, to avoid
leachate collecting on top of the liner
and causing the "bathtub effect," the
owner or operator must continue to
remove leachate from the collection
system during the post-closure care
period until leachate no longer is
collected in the system.
Proposed § 258.31(a)(3) would require
the owner or operator to conduct
ground-water monitoring during the first
30-year post-closure care period in
accordance with the requirements in
§ 258.50 and maintain the ground-water
monitoring system. The fundamental
purpose of monitoring during the post-
closure care period is to detect ground-
water'contamination hi a timely fashion
should the waste containment structures
fail and to trigger corrective action as
soon as contamination occurs. Long-
term monitoring is essential to detect
releases due to design or operating
errors (e.g., tearing of liners or disposing
of wastes that are incompatible with the
liner) and routine deterioration of liner.
Particularly for landfills designed with
advanced containment systems (e.g.,
liners,' leachate collection systems, or
synthetic final caps), ground-water
contamination may be delayed for many
years, thus increasing the need for long-
term monitoring. Because ground-water
monitoring wells are subject to routine
deterioration, post-closure activities
also should include the periodic
replacement of these wells as needed.
Finally, § 258.31(a)(4) proposes to
require the owner or operator to monitor
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33345
for methane in accordance with § 258.23.
That section requires the owner or
operator to ensure that methane ;
generated by the landfill unit does .riot
accumuJate in landfill structures
(excluding gas control or recovery
system components) in concentrations
in excess of 25 percent of the lower
explosive limit for methane, The
concentration of methane gas at the
MSWLF facility property boundary also
must not exceed the LEL. • ;
Following completion pf the first , .
phase of post-closure care at each
landfill unit, today's proposal would
require the owner or operator to conduct
a second, less-intensive phase of care.
The purpose of this second phase is to
ensure that a minimum level of care is
continued to detect any release that ,
might occur at an MSWLF in the long
term, while at the-same time minimizing
the burden on the owner or operator of
continuing extensive post-closure care
activities for an extended period of time..
Therefore, the Agency is proposing
under § 258.31(b) that the owner or
operator must continue, at a minimum,
ground-water monitoring and gas
monitoring in order to detect any
contamination that might occur beyond
the first 30 years of post-closure care.
States would have the responsibility of
specifying the duration of this second
phase. "•-...-'
The Agency is proposing this second.
phase of post-closure care for a number
of reasons. First, even the best liner and
leachate collection systems will
ultimately fail due to natural
deterioration, and recent improvements
• in MSWLF containment technologies
suggest that releases may be delayed by
many decades at some landfills. For this
reason; the Agency is concerned that
while corrective action may have
already been triggered at many
facilities, 30 years may be insufficient to
detect releases at other landfills. The
Agency, therefore, wants to ensure that
any potential release will be detected
regardless of when it occurs. Finally, in
the absence of sufficient data to follow
the Agency to predict with certainty
when containment systems are likely to
fail, a second phase of reduced post-
closure care ensures that releases will
be detected while minimizing costs to
the regulated community.
The Agency is proposing minimum
requirements for this second phase of
care to allow States maximum flexibility
in tailoring the scope of the
requirements and the duration of this
period to site-specific circumstances.
For example, if a release is detected at
an MSWLF during the second phase of
care, the State may specify increased
posNclosure activities to be carried put
'as necessary. For facilities located in-...
vulnerable environmental settings, the
State may wish to require the owner or
operator to continue during this, second
phase qf care many of the.activities
conducted during the first phase. In
addition, for vulnerable or high hazard
settings, the Agency expects States to
specify extended second-phase care
periods. In those cases in which
corrective action is still underway at the
end of the first phase of post-closure
care, the Agency expects States to
require the second phase of post-closure
care to extend for the duration of the
corrective action period, at a minimum.
In addition to the minimum post-
closure activities specified in today's
proposal, the Agency encourages States
to specify more detailed post-closure
care requirements, such as,maintaining
the vegetative cover through periodic
. mowing, replanting, and regrading to
preclude erosion that occurs naturally
over time and as a result of servere
storms, and repairing the cap when
necessary to prevent the cap from
becoming permeable. Other post-closure
care requirements could include security
measures if access to the MSWLF
facility could pose a health hazard. In
addition, the Agency encourages the
States to specify deadlines for
submitting monitoring data and other '.
recordkeeping requirements to facilitate
the detection of potential problems at
the site hi a timely manner. The Agency
requests comment ori the
appropriateness of incorporating these ,
and other post-closure care
requirements. .
The types of post-closure care .
requirements proposed today closely
parallel those applicable to Subtitle G
facilities. In addition, the post-closure
care activities proposed in today's rule
are consistent with existing State solid
waste management requirements based
on the Agency's review of several
States' solid waste regulations (Ref. 21).
All of the State programs reviewed
require, at a minimum, post-closure site
maintenance, leachate control, and
ground-water mohitpring. In addition to
these activities, many States surveyed
require additional post-closure activities
such as surface water monitoring. The
Agency in no way means to preclude
States from requiring such activities.
b.Length of Post-Closure Care Period,
As noted above, the Agency is
proposing that, following closure of each-
MSWLF unit, the owner or operator
must conduct two phases of post-
closure. In the first phase of post-closure~<
care, the owner or operator must
conduct all of the post-closure care
activities specified under f 258.31(a) for
a minimum of 30 years. The State has
the discretion to extend the period
beyond 30 years. Subtitle C establishes
a 30-year post-closure period and allows
the Regional Administrator to either
reduce or extend the length of the period
based on site-specific demonstrations.
As discussed above, the Agency is
concerned that releases may not occur
until after 30 years. In fact, the Agency
currently is considering extending the
length of the post-closure care period
wellb«yond 30 years for hazardous
waste facilities located in certain
environments likely to pose significant
threatsi to human health and the
environment. Therefore, today's rule .
proposes that the first phase: of pdst-
closure care must continue for a .
minimiam of 30 years, with the option for
States, to require a longer period if
deemed appropriate.
Section 258.31(b) proposes a second,
less intensive phase of post-closure care
designed to ensure the detection of
releases, but leaves to the States.the
flexibility to specify the appropriate
length of this period. States may specify
a standard period of care for all landfill
units, or determine an appropriate
period on a case-by-case basis (e.g., at
the time the MSWLF is applying for a -.
permit or within a specified period after
the effective date of the regulations).
While the first option would reduce the
burden on the States, the second option
could allow for better protection against
releases of hazardous constituents to the
environment by adapting the post-
clpsurij care period to site-specific
circumstances.
The Agency .considered requiring an
extended post-closure care period for
MSWIFa with an option to reduce the
period only if the owner or operator
could demonstrate that a reduction in '
the period would not pose any threat to
human health and the environment;
however, the Agency was concerned, ,
that this approach could be overly
stringeint and potentially burdensome to
the owner or operator and to the State to
establish the criteria for terminating the
post-closure care period. The Agency
also considered allowing the State the
discretion of reducing the 30-year post-
closure care period based on cause,
consistent with the Subtitle C
requirement for hazardous waste
facilities. As discussed above, however,
because improvements in containment
technology may delay the detection of
releases, the Agency is concerned that
reducing the period tp less than 30 years
• could result in rature releases not being
detected. :Finally, the Agency considered
requiring peripdscpnsistent with" sdme
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FederalRegiBter /Vol. 53, No. 168. Tuesday, August 30, 1988 / Proposed Rules
of the State post-closure care periods
(e.g., 5,10, or 20 years). In the absence of
empirical data from the States, however,
the Agency is not convinced that these
shorter periods are adequate to ensure
the protection of human health and the
environment.
EPA la not proposing criteria and
procedures for determining the length of
the second phase of the post-closure
care period although States are
encouraged to do so. States may wish to
consider several criteria when
evaluating the appropriate length of the
second phase of the post-closure period.
For instance, the liner and cover design,
age, stability, and operating record
(including ground-water monitoring
results that show changes in constituent
concentrations over time) of existing
landfills are useful factors in estimating
the potential for leachate and gas
release. Other factors include leachate
quality (e.g., volume and physical
characteristics), hydrogeologic
characteristics of the site, the potential
for human exposure, and the expected
future use of the facility and surrounding
land. The State also may wish to list in
the regulation the types of
demonstrations that owners or
operators must make to terminate the
post-closure care period.
The Agency is requesting comments
on the appropriate length of the post-
closure care period for MSWLFs. In
particular, the Agency is requesting
comments on the two-phased approach
and information on the frequency and
liming of releases from MSWLFs,
criteria that should be used to evaluate
the length of the post-closure care
periods, appropriate demonstrations for
terminating the post-closure care period,
and other information based on
experiences with closed landfills.
c, Post-Closure Plan. EPA is proposing
tn § 258.31(c) to require the owner or
opera tor of an MS WLF to prepare a
written post-closure plan that includes
descriptions of the monitoring and
maintenance activities required in
§ 258,31(a) and (b) for each MS WLF unit
and the frequency with which these
activities will be performed during both
phases of post-closure care. The
fundamental objective of monitoring is
to ensure that any migration of
contaminants Is detected in a timely
fashion. In many instances, post-closure
monitoring will be a continuation of the
monitoring activities conducted during
the landfill's active life. The description
of maintenance activities necessary to
ensure the integrity of the waste
containment systems should include
routine maintenance that reasonably
can be expected to be required after
closure of each unit (e.g., mowing,
fertilization, erosion control, and rodent
control) and the frequency with which
these activities will.be performed. These
monitoring and maintenance
requirements are consistent with State
regulations examined by the Agency.
EPA is proposing in § 258.31(c}(2) that
the post-closure plan also include lie
name, address, and telephone number of
the person or office to contact about the
MS WLF during both phases of the post-
closure care period. This requirement
would ensure that, if emergency
measures or long-term corrective
measures are necessary after closure, a
person familiar with the landfill design,
the types of wastes handled, past
operating problems, etc., will be
available.
The Agency also is proposing under
§ 258.31(c)(3) that the post-closure plan
include a description of the planned
uses of the property during both phases
of the post-closure care period. One
example of an acceptable use of a
closed landfill would be a recreational
park, provided the park complies with
the requirements of § 258.31(c)(3). Under
the proposed § 258.31(c)(3), the post-
closure use of the property must not
disturb the integrity of the final cover,
waste containment system, or function
of the monitoring systems unless the
State determines that the activities (1)
will not increase the potential threat to
human health or the environment or (2)
are necessary to reduce a threat to
human health or the environment. For
example, a foundation structure
installed in a closed MSWLF may
disturb the integrity of the cap, present
potential safety problems as result of
migrating landfill gas, and result in
structure failure. Interference with the
operation of the monitoring systems
could prevent timely detection of
ground-water contamination or gas
concentrations greater than the
established health-based limit.
Unmonitored access to the property
after closure also could result in the
release of hazardous constituents or
actual exposure of buried wastes as a
result of disturbances of the site. If an
owner or operator wishes to remove any
wastes, waste residues, the liner, or
contaminated soils at any time during
the post-closure care period, it must -
obtain approval from the State and
demonstrate that disturbing the site will
not increase the threat to human health
and the environment. These
requirements are consistent with the
Subtitle C requirements for hazardous
waste facilities.
d. Post-Closure Plan Deadline and
Approval. Consistent with the closure
plan requirements, the Agency is
proposing to require under § 258.31(d)
that the post-closure plan be prepared
as of the effective date of the rule or by
the initial receipt of solid waste at the
MSWLF, whichever is later. This section
also requires that the post-closure plan,
and any subsequent modification to the
plan, be approved by the State. As
described above, the Agency is leaving
specific procedural requirements such as
deadlines and procedures for
submitting, approving, and modifying
post-closure care plans to the individual
States/Finally, proposed § 258.31(d)
requires the owner or operator to •
maintain a copy of the most recent
approved post-closure plan at the
MSWLF facility or at some other
location designated by the owner of
operator. The plan must be maintained
from the onset of the post-closure care
, period until completion of the post-
closure care period has been certified in
accordance with § 258.31(f) (see Section
12.f below) and the owner or operator
has been notified by the State that it has
been released from financial assurance
for post-closure care for the entire
landfill under § 258.32(g).
e. Notation on tKe Deed to Property.
The Agency is proposing in § 258.31(e)
that, following closure of the entire
MSWLF, the owner or operator must
record a notation on the deed or some
other instrument normally examined
during a title search that will notify any
potential purchaser that: (1) The land
has been used as an MSWLF and (2) its
use is restricted under § 258.31(c)(3).
This notation on the deed is intended to
assure that the land use is restricted in
perpetuity. The owner or operator may
ask permission to remove the notation
on the deed if all wastes are removed in
accordance with the provisions in
§ 258.31(c)(3). Under the Subtitle C
requirements for hazardous waste
disposal facilities, an owner or operator
must record a notice on the deed
following closure of the first unit and
after final closure to provide additional
assurance that all parties are aware of
the use of the property. While today's
proposed rule does not require that a
notation to the deed by filed after
closure of each landfill unit in order to
minimize burdens on the owner or
operator, States may wish to adopt this
more stringent requirement.
According to the Agency's survey of
State requirements, some States already
have procedures for ensuring that the
post-closure use of landfill property is
restricted. Some States require a
notation to be put on the property deed;
other States require that proposed future
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33347
land use be subject to Agency review
and approval.
States may wish to specify additional
notification requirements for MSWLFs
as required under Subtitle C, For
example, submission of a survey plat
indicating the location and dimension of
landfill units, a record of waste •
including the type, location, and
quantity of waste disposed of in each
landfill unit, and a certification that the
deed notation has been recorded are all
required under Subtitle C regulations.
/. Post-Closure Care Certification. The
Agency is proposing in § 258.31(f) that
following the completion of the second
phase of the post-elqsure care period for
each unit, the owner or operator submit
to the State, a certification that both
phases of po'stclosure care have been
conducted in accordance with the
approved post-closure plan. Consistent
with the closure certification, the post-
closure care certification must
objectively verify that post-closure care
has been performed in accordance with
the post-closure care requirements
based on a review of the landfill unit by
a qualified party. As discussed above
for closure certifications, the Agency is
proposing to leave to the State the
discretion to specify the types of '
certficatiqns that would provide such an ;
objective assessment.
Today's proposal requires that the
certification be submitted at the
completion of the second phase of the
post-closure care period for each unit.
This requirement is consistent with
these for hazardous waste facilities
under Subtitle C. Because of the
duration of the post-closure care period,
the States may wish to require periodic
interim certifications (e.g., every five or
10 years "or at the time of the permit
renewal, if applicable) to confirm that
activities are being conducted properly.
Alternatively, States may wish to
consider requiring a certification after-
the end of each of the two phases of
'post-closure care.
13. Section 258.32 Financial Assurance
Criteria
Under today's proposed rule, the
owner or operator of a new or existing,
MSWLF would be required to
demonstrate financial assurance for the
costs of.conducting closure, post-closure
care, and, if applicable, corrective action
for known releases. (Under proposed
§ 258.57, whenever the ground-water
protection standard is exceeded, an
owner or operator must conduct a
corrective action program to treat in
place or remove any Appendix II
hazardous constituents exceeding the
standard.) The purpose of financial
assurance is to ensure that the owner or
operator adequately plans for the future
costs of closure, post-closure; care, and
corrective action for known releases,
and to ensure that adequate funds will
be available, when needed to cover
these costs if the owner or operator is
unable or unwilling to do so. To
demonstrate to the State that it has
planned for future costs, the owner or
operator must prepare written cost •
estimates. These cost estimates would
serve as the basis for determining the
amount of financial assurance that must
be demonstrated., >
Today's proposed financial assurance
requirements for closure, post-closure
care, and corrective action for known
releases at MSWLFs are patterned after
the financial assurance provisions for
hazardous waste facUities under
Subtitle G, and proposed provisions for
underground storage tanks under .
Subtitle I. Financial assurance for .•:-
closure and post-closure care for
MSWLFs is currently required in
numerous States. Although financial
assurance for corrective action is less
frequently required by States, the
Agency believes that provision of
financial assurance to cover the costs of
corrective action for known releases is
important to ensure that funds for long-
term remedial activities" are provided by
the owner or operator.
The Agency is not proposing at this
time to require financial assurance for
other than known releases due to the
complexity of the analysis that would be
required to estimate probable corrective '
action costs associated with releases
from MSWLFs. For example, to require a
facility with a high probability of a
release to demonstrate financial
assurance for corrective action costs in
the event of a release iwould require a
characterization of the risks posed by a
facility as well as the potential size,
impact, and costs to remedy such
releases. Such* facility risk analyses
could require considerable time to
complete' and also could delay the
adoption and implementation of
regulations by States. The Agency
requests comments on this decision' and
information concerning how such cost
estimates could be derived in the event
additional corrective action financial
responsibility requirements are
proposed in the future.
The Agency also considered requiring
owners or operators of• MSWLFs to
demonstrate financial assurance for
third-party liability to compensate
injured third parties. For'a number of
reasons, however, the Agency has
decided to defer proposing such liability
requirements at this time. First, the
Agency is concerned that it does not
have sufficient-data at this "time to
specify the amount, of liability coverage
that would be appropriate for an
MSWLF. Unlike Subtitle I, which
mandates a minimum level of coverage
for underground storage tanks, the '
statute does not specify any minimum
financial assurance requirements for
MSWLFs. To date, few claims data exist
concerning .third-party awards resulting
.from releases at MSWLFs. While more •
data are available, to assess potential
claims; from Subtitle (^facilities, the .
Agency is reluctant to extrapolate from
these data or to adopt directly the levels
of coverage required for Subtitle C :
facilities without further analysis
comparing the risks and resultant third-
party claims from MSWLFs and Subtitle
C hazardous waste facilities.
.-•Second, RCRA Section 4010(c) allows
the Agency discretion to'take into :
account the practicable capability of
MSWLFs when developing the new
criteria/Today's proposal .applies an
. extensive set of hew regulations to a
large universe of waste facilities.
Therefore, in light of the costs
associated with implementing today's
proposed requirements, the lack of
available data on awards for third-party
damage:?, and the current constraints in
the insurance market, the. Agency has
tentatively decided to defer any third-
parry liability requirements. Instead, the
Agency has chosen to focus on financial
assurance requirements, for costs of ... .
activities that are certain to be incurred
(i.e., closure, post-closure care, and .-
corrective action for known releases). In
deferring these requirements, the
Agency hopes to provide more time for
the liability insurance market to adjust
to a new potential market. The Agency
adopted a similar approach when
promulgating liability coverage
requirements for Subtitle C requirements
when it phased in the requirements over.
a three-year period to allow'the market
to adjust to the demand for increased
capacity.
Deferring third-party liability
coverage requirements at the time,
however, does not preclude the Agency
from promulgating such a requirement
for MSWLFs at a later date. Further, the
Agency encourages States to consider
requiring such coverage if they choose.
This decision to defer these financial
assurance requirements in no way
relieves an owner or operator of liability
should injury to third parties be shown.
to have resulted from the operation of
MSWLFiS. '.',.-. ,. ,- , ; -
The Agency requests comments on
this decision to defer requirements for "*
financial assurance for third-party '
liability iGosts at this time. In particular,
the Agencyrequestsinformation to
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33348
Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
assist in setting appropriate levels of
liability coverage forMSWLFs,
including data on the number of claims
filed, the size of settlements or awards
resulting from injuries associated with
releases from MSWLFs, the causes of
such injuries, and the number of persons
harmed. Data concerning the nature,
size, probability of, and potential
exposures to releases from MSWLFs
could also be used in developing
liability coverage requirements, EPA
also requests information on the likely
availability and cost of insurance
coverage and other financial
instruments for liability coverage, the
factors that might affect the cost and
availability coverage, the factors that
might affect the cost and availability of
financial assurance instruments, the
potential burden on owners or operators
of obtaining financial assurance, and the
advisability of phasing in financial
responsibility requirements for third-
party liability as done under Subtitle C.
Today's rule proposes that the amount
of financial assurance for closure, post-
closure care, and corrective action for
known releases be based on site-
specific cost estimates. The Agency is
not proposing in today's rule the types of
mechanisms that may be used to
demonstrate financial assurance.
Rather, today's proposal establishes a
performance standard that specifies a
set of criteria that must be satisfied by
any mechanism that is used. Regardless
of the mechanism chosen, it must ensure
that adequate funds are available in a
timely manner whenever they are
needed. This approach provides the
regulatory community and the States the
maximum flexibility in satisfying the
financial assurance requirements.
a. Applicability. Today's proposal
would apply to each owner and operator
of an MSWLF except for an owner or
operator who is a State or Federal
government entity. Although these
proposed requirements would apply to
both the MSWLF owner and the
operator, only one would be required to
demonstrate financial assurance for the
MSWLF. This requirement is consistent
with those under Subtitles C and I. This
option provides flexibility to the
.regulated community by allowing them
to choose which party will demonstrate
financial assurance while, at the same
time, giving the State the additional
assurance that funds will be available
by holding both parties ultimately
responsible. EPA considered, but
rejected, the option of requiring both the
owner and operator to demonstrate
financial assurance. While such an
approach might provide somewhat
greater assurance that the costs of
closure, post-closure care, and
corrective action for known releases
would be covered in the event that one
party failed to provide adequate funds,
the Agency believes that, in most cases,
this "double" coverage would be
unnecessary and would substantially
increase the burden on owners and
operators of MSWLFs.
EPA recognizes that because Federal
and State government entities are
permanent and stable institutions that
exist to safeguard health and welfare,
they have the requisite financial
strength and incentives to cover the
costs of closure, post-closure care, and
corrective action for known releases.
The Agency believes, therefore, that it is
not necessary to impose financial
assurance requirements on MSWLFs
owned or operated by government
entities whose debts and liabilities are
the debts and liabilities of a State or the
United States. This exemption also
extends to cases in which an MSWLF is
owned by a State or Federal government
entity and operated by a private party
(or operated by a State or Federal
government entity while owned
privately). A State or Federal owner
may, of course, require the private
operator by contractual agreement to
provide financial assurance. The
exemption for MSWLFs owned or
operated by Federal or State
governments is consistent with the
approach adopted under both the
Subtitle C regulations applicable to
owners or operators of hazardous waste
facilities and the proposed Subtitle I
rules for underground storage tanks
containing petroleum.
The Agency also is considering
whether to treat Indian Tribes, having
Federally recognized governing bodies ,
that carry out substantial governmental
duties and powers over any area, as
States. If so, they would be considered
exempt from financial assurance
requirements. If Indian Tribes are not
exempt, they would be required to
demonstrate financial assurance similar
to local governments. The Agency
requests comment on whether to exempt
Indian Tribes from financial
responsibility requirements. Specifically,
the Agency requests information on
whether Indian Tribes have the requisite
financial strength and incentives to
cover the costs of closure, post-closure,
and corrective action for known
releases.
With regard to financial assurance
requirements for local governments,
EPA carefully considered whether to
require municipal oxvners and operators
of MSWLFs to demonstrate financial
assurance for the costs of closure, post-
closure care, and corrective action for
known releases. While the Agency
recognizes that many local governments,
like Federal and State governments, are
permanent entities and act to secure the
well-being of their citizens, the Agency
is concerned that local governments
cannot provide the same guarantee that
they will be able to access adequate
funds to pay for environmental costs in
a timely manner.
EPA has determined that, relative to
Federal and State government entities,
local government entities generally: (1)
.Have more limited financial resources
and less flexibility in their annual
budgets, making reallocation of a
substantial amount of funds for a
specific purpose in a given year
extremely difficult; (2) cannot
. necessarily access the traditional
sources of. municipal financing (i.e.,
intergovernmental transfers, bond
issues, and taxes) quickly enough to
ensure funding in a timely manner; and
(3) have been more prone to fiscal
•emergencies than Federal and State
government entities. The Agency
believes, therefore, that local
government entities should be subject to
financial assurance requirements as a
tool to induce advanced planning for the
future environmental costs of closure,
post-closure care, and corrective action
, for known releases. Moreover, the
Agency believes that requiring local
governments to demonstrate financial
assurance may help them to raise funds .
for these costs that they ultimately will
have to cover.
b. Cost Estimates. EPA is proposing in'
§ 258.32 (b), (c), and (d) that the owner
or operator of each MSWLF develop
written site-specific estimates of the
costs of conducting closure, post-closure
care, and corrective action for known
releases that would be used to
determine the amount of financial
assurance required under § 258.32 (f),
(g), and (h). These cost estimates must
account for the costs, in current dollars,
of a third party conducting the activities
described in the closure and post-
closure plans and in the corrective
action program as specified in §§258.30,
258.31, and 258.58. The "third party"
provision ensures that adequate funds
will be available for the State to hire a
third party to conduct closure, post-
closure care, and corrective action in the
event that the owner or operator fails to
fulfill these obligations. These
requirements parallel the requirements
or proposed requirements under
Subtitles C and I.
The closure cost estimate must be
based on the cost of closing the MSWLF
at the point in the landfill's active life
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when the extent and manner of its _
operation would make closure (as
described in the closure plan) the most
expensive. For example, if an owner or
operator operates the MSWLF on a cell-
by-cell basis, the estimate should
account for closing the maximum area of
the landfill ever open at any time.
The Agency is proposing that the
owner or operator develop estimates of
the costs of hiring a third party to
.conduct post-closure care activities for
each phase of the post-closure care
period. The cost estimate for each phase
must be based directly on the activities
described in the post-closure care plan'
required under § 258.31 (c) arid account
for the entire landfill. The estimate for •
each phase would be derived by
multiplying the annual costs (in current
dollars) of the activities by the number
of years of care required in that phase.
This approach is similar to the Subtitle
C calculation of the post-closure care ,
cost estimate, in which the cost estimate
is determined by multiplying the annual
post-closure .cost estimate by the
number of years of post-closure care.
Because not all post-closure care
activities.are conducted on an annual
basis (e.g., cap replacement or
monitoring-well replacement may only
be required periodically), the total cost
estimate must be adjusted to include
these periodic costs as well as the
annual costs. To ensure that adequate
funds would be available for the entire
post-closure care period, the Agency is
requiring that the post-closure care cost
estimates for each phase of post-closure
care account for the;most expensive
costs of routine post-closure care. For
example, the costs of monitoring during
the first 30-year phase should account
for the most extensive monitoring likely
to be required.
As noted above, Subpart E of today's .
rule proposes to require that whenever
the ground-water protection.level at the
MSWLF is exceeded, an owner or
operator must conduct corrective action.
Once a release has been detected, the
owner or operator must prepare an . ,
estimate of the cost of the corrective
action program, calculated by "
multiplying the annual costs of remedial
actions and the number of years .
.required to complete the corrective
action program.
; The proposed rule would require the
closure and post-closure cost estimates
to be adjusted annually for inflation
until the entire landfill has been closed.
The cost estimate for corrective action
activities must be updated fpr inflation
until the end of the corrective action
period even if it extends beyond closure
of the MSWLF. These requirements are
consistent with the Subtitle C
requirements. Also consistent with
Subtitle C requirements, today's -
proposal would not require the owner or
operator to update the post-closure cost
estimate after the entire landfill has
been closed; however, the Agency _'-
requests comment on the desirability of
requiring annual adjustments of the
post-closure cost estimate during the ;
post-closure care period to prevent a / '
significant shortfall in funds, which
could result from not accounting for
future inflation.
The Agency suggests that the States
require the use of inflation,factors that
are readily available to owners and
operators (e.g., Implicit Price Deflator for
Gross National Product as published.in
the "Survey of Current Business," a
Department of Commerce publication)
or specify other inflation factors that
must be used to adjust the estimates.
States may wish to refer to the
provisions in 40 CFR 264.142 and 264.144
and the accompanying guidance
materials in developing these
^equirementsl
In addition to updating estimates for
inflation, today's proposed rale also
would require that the owner or .
operator increase the closure and post-
closure cost estimates when changes to ,
the plans or changes at the facility
during the active life increase the cost *
estimates (e.g., increase in design
capacity, increase in the maximum area
open, more extensive monitoring
requirements). Similarly,, today's rule
proposes that an owner or operator must
increase the corrective action cost .
estimate anytime a change in the
corrective action program or in the
facility conditions increases the cost
estimate.
Whenever the cost estimates are
increased, the owner or operator must
increase the level of financial assurance,
required under § 258.32 (f), (g) and (h). If
the owner or operator can demonstrate
that changes in the facility result in a "
decrease in the maximum costs of
closure over the active life of the landfill
(e.g., reduction in size of the area to be
used for the landfill), the owner or
operator may submit a request to the
State to reduce the closure cost
estimate. The owner or operator may .
request a reduction in the amount of the
post-closure care cost estimate if the
owner or operator can demonstrate that
the cost estimate exceeds the maximum
cost of post-closure care over the
remaining post-closure care period.
Because the proposed rule would not
require the post-closure cost estimate to
be adjusted for inflation during the post-
closure care period, the~ State should
account for future inflation in
determining if the estimate exceeds the
remaining costs to be incurred over the J
length of the period. Because the
corrective action cost estimate is
adjusted for inflation;until the;.-.;...'•
completion of the program, the owner or
operator may more easily be able to
demonstrate that the original estimate
. exceeds^ the remaining costs to be
incurred. " ' .
The-Agency is not proposing
procedures or deadlines for estimating •'
and adjusting cost estimates. However,
the Agency encourages States to do so
and refers them to the Subtitle C .--•;:
provisions in 40 CFR 264.142 and 264.144
for guidance. la addition, the Agency
strongly encourages States to consider
carefully all requests for reductions in
cost estimates to ensure that shortfalls
in coverage do not result. The Agency
asks forcomments on whether the
revised Criteria should include
'.procedures.or deadlines for estimating -
and adjusting cost estimates.
For rficprdkeeping purposes, the
owner or- operator must maintain copies
of the most recent cost estimates for
.closure, post-closure care, and -
corrective action for known releases at ,
the landfill'unit until the owner or
operator has been released from
financial assurance for that activity
under § 258.32 (f), (g), and (h). These
provisions are consistent with .'-,-
requirements under Subtitle C.
c. Performance Standard for Financial
Assurance. In order to minimize the
number of specific procedural
requirements applicable to • , "'
. demonstrating financial assurance .and
provide maximum flexibility to the .
States, 'the Agency-is not specifying in :
the proposed regulation the types of
financial assurance mechanisms that
would be allowable; however, the
Agency is concerned that the .
mechanisms allowed by the States (e.g.,
trust funds, letters of credit, State fund)
satisfy (the overall ojbectives of financial
.assurance, i.e., to ensure that adequate
/funds are readily available to cover :the
costs of conducting closure, post-closure
care, and corrective action for known
releases.' if the owner or operator fails to.
do :so. Therefore, the Agency is
proposing in § 258.32(e) of today's rule a
performance standard for financial -";
. .assurance .that must be satisfied to -.-
demonSitrate financial assurance under
§ 258.321.(f), (g), and (h):
Under the performance standard,
financial assurance mechanisms
allowed by a State must: (1) Ensure that
the amount of funds assured is sufficient
to cover the costs of closure, post-
clbsure care, and corrective action tor:
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1968 / Proposed Rules
known releases when needed; (2) ensure
that funds will be available in a timely
fashion when needed; (3) guarantee the
availability of the required amount of
coverage from the effective date of these
requirements or prior to the initial
receipt of solid waste, whichever is
later, until the owner or operator is
released from financial assurance
requirements under § 253.32(f), (g), and
(h); (4) provide flexibility to the owner
or operator; and (5) be legally valid and
binding and enforceable under State and
Federal law.
The financial assurance mechanisms
authorized under Subtitle C and
proposed under Subtitle I, if properly
drafted, satisfy these performance
criteria. Subtitle C allows the use of a
trust fund, letter of credit, surety bond,
insurance, financial test, corporate
guarantee, State-required mechanism,
State assumption of responsibility, or a
combination of certain mechanisms to
demonstrate financial assurance for
closure and post-closure. (Insurance was
not proposed for corrective action
financial assurance under Subtitle C
because the Agency determined that it
would not be available.) The proposed
Subtitle I regulations (52 FR12768, April
17,1987) allow a similar set of
instruments to demonstrate financial
assurance for corrective action and
liability coverage. States may wish to
refer to the background document for
closure and post-closure care and
financial responsibility (Ref. 4) for more
Information on the use of these
mechanisms in other EPA financial
assurance programs and guidance on
how these mechanisms could be
structured to satisfy the performance
standard discussed below.
The; financial assurance performance
standard in today's proposal would
require Stated to adopt a program under
which the selected range of financial
assurance mechanisms ensures that
sufficient funds will be available to
cover the costs of conducting closure,
post-closure care, and corrective action
for known releases whenever such funds
are needed. In most cases, the amount of
funds assured should equal the full
amount of the current site-specific cost
estimates for closure, post-closure care,
and corrective action at the time the
mechanism i$ established. For example,
if a letter of credit issued fay a bank is
an allowable mechanism, its face value
must equal the site-specific cost
estimate. To minimize the burdens on
small owners or operators who may
have to set aside funds in a trust to
demonstrate financial assurance. States
may wish to adopt tne approach used
under Subtitle C. Under Subtitle C,, an.
owner or operator is allowed to build up
the trust fund over the life of the facility
or over 20 years (10 years for permitted
facilities), whichever is shorter. To meet
the performance standard criteria under
today's proposal, if a build-up period is
' allowed for trust funds, the State must
require the trust to be fully funded no
later than .the end of the landfill's active
life. States may wish to adopt stricter
trust fund requirements (e.g., shorter
build-up period, accelerated payments
into the trust in the earlier years of
operations) to avoid potential shortfalls
if the MSWLF is closed earlier than
expected. If a State chooses to develop a
State fund to be used for the costs of
closure, post-closure care, and
corrective action for known releases, the
size of the fund must be commensurate
with the expected costs likely to be
incurred to satisfy the performance
standard.
To ensure that funds will be available
when needed, States also may need to
take into account potential legal and
political constraints on accessing funds
guaranteed by financial mechanisms.
For example, because the U.S. EPA
Regional Administrator does not have
the authority to directly receive funds
from third-party financial assurance
mechanisms (i.e., all monies received
must be directed to the U.S. Treasury),
under Subtitle C a standby trust fund
must be established when certain
instruments are used (e.g., letter of
credit and surety bond) to serve as. a
depository for the funds if the Regional
Administrator draws on the instrument.
Some States may face similar
constraints in accepting funds directly
from third parties and may need to.
establish standby trust fund
requirements for certain mechanisms
(e.g., letters of credit), to ensure that the
State, has access to the funds whenever
they are needed.
Because of the long period between
the initial establishment of the financial
assurance mechanism and the time that
the costs are incurred, the performance
standard requires that the. mechanisms
guarantee continued availability of
coverage until the owner or operator
establishes an alternate financial
assurance mechanism or is released
from financial assurance requirements
to avoid potential gaps in coverage.. To
ensure reliability over time, States
should establish provisions that address
contingencies such as (1) bankruptcy or
incapacity of the financial assurance
provider or the landfill owner, or
operator and (2) cancellation or
termination of mechanisms by the
provider. To. prevent gaps- in coverage in
the event of these contingencies,. States
must ensure that owneics or operators
establish alternate financial
mechanisms- in a timely manner. For
example, States could require that only
after obtaining alternate assurance
could the present mechanism be
cancelled or terminated. States also
could specify notification requirements
and time limits for providing alternate
financial assurance, similar to
provisions under Subtitle C.
Furthermore, States may wish to adopt
provisions similar to Subtitle C
regulations that require certain
mechanisms to be automatically
renewed unless an alternate financial
assurance mechanism has been
established, or else the third party
offering the-instrument becomes liable
for the obligation. Finally, States must
ensure that owners or operators of
MSWLFs cannot terminate financial
assurance at will, which could
jeopardize the availability of funds
when necessary. For example, Subtitle C
requires that financial assurance cannot
be terminated until after the
certifications of closure or post-closure
careJiave been received and approved.
In authorizing, financial assurance
. mechanisms for demonstrating financial
assurance, States: should provide a
range of mechanisms to provide owners
or operators of MSWLFs with flexibility
for demonstrating compliance while at
the same time ensuring that they meet
the regulatory requirements. For
example, the Agency would not consider
a program sufficiently flexible if that;
program restricted owners or operators
to using only a financial test or
insurance because such restrictions
would likely impose a significant burden.
on much of the regulated community.
Finally, under the performance
standard, the financial assurance
mechanisms must be legally-valid and
binding. The validity of such
mechanisms will largely be a matter of
State law. However, to be legally valid,,
a financial assurance mechanism must
be issued by an institution that has the
legal authority to issue the mechanism
and that is legally acceptable and/or
regulated by, a Federal or State: agency.
Financial assurance mechanisms also
must be enforceable under. State and.
Federal law. To help ensure that the,
mechanisms are enforceable, States may
wish to specify wording for the
mechanisms consistent with the
regulations found in 40 CR 264.151,
These mechanisms are discussed in a
background document to this proposed
rule (Ref. 4).
In proposing a financial assurance
performance standard rather than
specific financial assurance;
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33351
mechanisms, the Agency has sought to
minimize inconsistencies with the
approximately 20 States that already
have financial assurance requirements
for MSWLEs. The Agency recently
conducted case studies of nine such
programs (Ref. 19). The study found
considerable variation among State
programs both in the types of
mechanisms allowed and in the
procedural requirements for the ,. ;
financial assurance mechanisms. For
additional detail on the results of the
case studies, see the financial assurance
background document to this rulemaking
[Ref. 19). Today's proposal is, therefore,
designed to accommodate the variations '--
among existing State programs, while
ensuring that all programs meet the
performance standard for financial
assurance. The Agency requests
comments on the proposed financial -
assurance performance standard,
including the use of this standard rather
than identifying a list of acceptable
financial assurance mechanisms.
•d. Financial Assurance Provisions for
Local Governments. As noted in the
previous section, the Agency is not
proposing specific financial mechanisms
in today's rule in order to provide
maximum flexibility to the States. The
Agency believes that the Subtitle C
provisions can be used as models for
States in developing their rules. Unlike
Subtitle C, however, the majority of
MSWLFs are owned by local
governments. While Subtitle C allows a
financial test to- be used to demonstrate
financial assurance, the testin 40 CFR
284.143 and 264.145 is designed primarily
for corporate firms and isnot directly
applicable to local governments. •
Therefore, because of the large number
of MSWLFs owned by local'.
governments, the Agency considered for
today's rule the feasibility of developing
a financial test that would exempt local
governments able to pass the test from
; having to obtain a third-party financial
assurance mechanism [or contribute to a
State Fund; if applicable).
• A financial test designed specifically
for local governments was considered
during the development of the Subtitle C
regulations but was not included due to
difficulties in interpreting and verifying
municipal accounting information,
concern over the use of bond ratings as
a measure of fiscal strength, and
concent over the accessibility of
allocated tax revenues. However, since
the promulgation of the Subtitle C
requirements, many local governments
have developed more sophisticated
financial management practices;
Because of these changes, the Agency is
examining possible approaches a State
might use in developing such a test. ,
specifically for Icoal governments. For
example, the Agency is examining the
feasibility of developing a special test
that takes into account fiscal, .-
institutional, and other factors. Although
the Agency is not proposing a financial
test for local governments in today's
rule, the financial assurance background
document discusses a framework that
States may wish to use in specifying
criteria for a financial test for local
governments [Ref. 4). If a State decides
to allow a financial tesffor local ;
governments, the framework should be
useful in choosing appropriate measures
of a local government's financial
strength.
The Agency requests comments on the
use of a financial test for local
governments/Specifically, EPA requests
information on standards that might be
used to measure a local government's
financial strength, the measures that
might be taken to establish such a
financial test, and whether any States
currently allow a financial test for local
governments.
e. Financial Assurance Requirements.
As noted in Sections 13.b and c, site-
specific cost estimates are used to
determine the amount of financial
assurance required.The mechanisms
used to demonstrate this amount of
coverage must satisfy the performance
standard specified in § 258.32(e).
The amount of closure financial
assurance must bs based directly on the
most recent closure cost estimate
adjusted for inflation in accordance with
§ 25S.32(b). Financial assurance for post-
closure care must cover the costs of
conducting both phases of the post-
closure care period for the entire
landfill. The amount of financial
responsibility required for each phase of
post-closure care is calculated by
multiplying the nipst recent annual post-
closure cost estimate for each phase of
post-closure care by the number of years
hi that phase. The sum of these two
estimates is the amount of financial
assurance required for post-closure care.
This approach is similar ta the Subtitle
C calculation of the post-closure care :
cost estimate, in which the cost estimate
is determined by multiplying'the annual
post-closure cost estimate by the ;
number of years of post-closure care.
EPA is proposing in § 258.32(h} to
require corrective action financial
assurance for known releases in an
amount equal to the most recent annual
corrective action cost estimate in ~-'.;
§ 258.32[d)"times the number of years
required to complete the corrective
action program. The Agency is
proposing that financial assurance for
corrective action be demonstrated after
the cost estimate has been prepared in
accordance with § 258.32[d), consistent
with Subtitle C. Before adopting this
timing requirement, the Agency
considered the feasibility of requiring
someiminimal level of financial
responsibility for corrective action as
soon as;the need for corrective action
was demonstrated but before the
corrective action, measures and costs
were'determined. This latter approach
has been proposed for Subtitle I because
tiie statute requires financial assurance
for corrective action for a specified
amomt ($1 million) before there is any
known contamination. The Agency,
concluded, however, that it still does not
have the data sufficient to estimate the
cost of corrective action, in advance and
is delaying the requirement until a
.release has been detected and the
estimates of costs have been developed.
States may wish to require some level of
financial assurance to cover the costs of
interim, measures that may be taken
prior to the completion of the corrective .
action plan and the approved cost
estimate. - ,
Release from financial assurance
requirements for closure, post-closure
care,, and corrective action is triggered
by State approval of the certifications
submitted to the State undet
§§ 2Ei8.30[e), 258.31(f), and 258.32(h).
Following the receipt of the certification
from, the owner or operator that verifies
thatClosure, post-closure care, or
corrective action have been completed
in accordance with the approved plans,
today's rule proposes in § 258.32 [f)t [g),
and jh] that the State'notify the owner ,
or operator hi writing that he no longer
is required to demonstrate financial
responsibility for these activities. If the
Statei has reason to believe that the
activities have not been conducted in
accordance with the approved plan, it
must notify the owner or operator and ,
include a detailed statement of reasons
for not releasing the owner or operator
from the financial assurance
requirements. .
D.SubpartD—-Design Criteria
1. Overview of Proposed Standards'
a. New Units. Section 258.40{a) of
today's proposal would require that new
MSVlfLF units be designed with liner
systems, LGS, and final cover systems
as necessary to meet the design goal in
the aquifer at the waste management
unit boundary or an alternative
boundary specifiecL by .the State. The
two 'key components of this performance
standard are the design goal, which is a
humian health- and environmental-based
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33352
Federal Register / Vol. 53. No. 168. Tuesday, August 30, 1988 /Proposed Rules
ground-water risk level, and the point of
compliance [POC) in the aquifer (i.e., the
waste management unit boundary or an
alternative boundary specified by the
State). Today's proposal provides States
considerable flexibility in establishing
both of these key components. As
discussed below, the State establishes
the design goal within the protective risk
range and also may set an alternative
boundary as the point of compliance;
however, this boundary shall not exceed
150 meters from the waste management
unit and shall be located on land owned
by the owner or operator of the MSWLF.
In this proposal the Agency is
considering three alternative risk
ranges. These are 1X1CT4 to 1X10~7, a
fixed level of 1 X10~5, or an upper bound
risk level of IXICr4 (with States having
discretion to be more stringent], EPA is
proposing to use the range of !X10~4to
1X10"7 because the Agency currently
uses this range in clean-up activities at
sites and because this wUl provide a
margin for consideration of site specific
factors in setting the risk level. A fixed
risk level of 1X10~S would provide a
uniform level of protection across all
States. On the other hand, setting an
upper bond risk level of 1 X10~4 would
allow States greater flexibility in
establishing more stringent risk levels
based on site specific conditions.
In its regulatory actions EPA generally
uses a case-by-case approach,
depending on the surrounding issues,
uncertainties, and information bases.
Such a case-by-case approach allows
flexibility in judging the variety of
factors and uncertainties included in the
risk assessments. For example, the
following risk levels have been
embraced by EPA since 1984:
• The Superfund Clean-up policy—
10-«to10-7.
• Alternate Concentration Limits
(ACLsJ—10~« to 10-' with KT * target.
• Drinking water standards/
Maximum Contaminant Level (MCLT—
io-
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33353
For the above reasons, EPA believes
the 150-meter maximum alternative POG
allows'for consideration of the
practicable capability of the regulated
community and State flexibility in
setting design criteria while ensuring
protection of human health and the
environment. The Agency requests
comment specifically on the use of this
distance to establish an alternative
boundary.
, In implementing .today's proposed
performance standard under § 258.40(a),
States have two options. Under the first
option, the State may establish a
performance standard (including the
design goal and point of compliance
within the limits prescribed in
§ 258.40(a)) for each facility on a case-
by-case basis. For example, after ;
considering site-specific factors, the
State may set a performance standard
for one MSWLF that specifies a design
goal of lxlO~5risk to be met at the .
waste management unit boundary, while
at another MSWLF, the State may
require a design goal of lX10~6to be
met at an alternative boundary. In
setting this alternative boundary, the
State must fully consider the factors
specified in § 258.40(d).
Under the second option, a State may
establish one performance standard
(including the design goal and point of
compliance) that applies to all MSWLEs
in the State. For example, the State may
elect to establish a performance
standard that requires all new MSWLFs
, hi the State to be designed to meet a risk
level of. 1X10~6 at the waste
management unit boundary. If a State
wishes to incorporate an alternative
boundary (i.e., other than the waste
management unit) into its State-wide
performance standard, the State must
carefully consider all the facility-specific
factors required under § 258.40(d). The,
Agency believes that this method may
be difficult in States that have a large
number of MSWLFs.
Regardless .of whether the
performance standard is set on a site-
specific basis or a State-wide basis, the
State must still determine MSWLF
. designs that meet the performance
standard. Section 258.40{d) requires the
State to consider at least the following
factors in determining the specific
design necessary to meet the --'
performance standard: (1) The
hydrogeologic characteristics of the
f acility and surrounding land, (2) the
•climatic factors of the area, (3) the
volume and physical characteristics of
the leachate, (4) proximity of ground-
water users, and (5) ground-water
quality. Various methods for considering
these factors and determining ~. ' l~
appropriate designs are discussed later
in this preamble (see Part 5 of this
section).
In certain cases, the State may find
that MSWLF designs required under its
existing regulations adequately meet a
State-wide performance standard
established in accordance with Subpart
D of today's proposal. In such cases, the
• State may use its existing regulations to
implement today's proposed
requirements for new MSWLF design.
The Agency specifically requests
comments on the approach to State
implementation of today's proposed
§ 258.40(a) performance standard. '
b. Existing Units. The Agency is
proposing a different performance
standard for existing units than for new
units. For existing units, § 258.40(e) of"
today's proposal would require
installation of a final cover system that
prevents infiltration ofliquids through
the cover and into the waste. In
proposing a different standard for
existing units, the Agency is taking into
account the practicable capability of
owners and operators of MSWLFs. EPA
recognizes that most existing units have
not been specifically designed to meet
the design goal at the waste _
management unit boundary. However,
some States have design and "'_'-•-•
performance requirements for MSWLFs
that, if properly implemented, may have
resulted in landfill designs that are
capable of meeting the design goal for
new units. Further, MSWLEs
constructed after the promulgation of
the 1979 Criteria (40 CFR Part 257)
should have been designed and
operated to ensure that the
concentration of contaminants
introduced to the ground water did not
.exceed the MGLs specified in the Part
257.
EPA believes that to require existing
units to meet the same performance
standard as new units would seriously
strain the resources of the regulated
community. First, the data necessary to
make the determination of whether the •
existing unit meets the design goal, such
as the geology beneath the unit or the
original design specifications, may not
be readily available or may be very
costly to obtain.This lack of information
was evident in several of the case
studies.EPA reviewed in developing of
this proposal. Second, if the design of
the existing unit was determined to be
incapable of meeting the design goal,
retrofitting would be necessary. The
Agency believes retrofitting for Subtitle
D facilities should not be required
because (1) the procedure is impractical
because it requires the'excavation and,
temporary storage or disposal of wastes,
(2) the excavation of the. waste may
create its own set of public health
problems (e.g., dangers to workers;
contaminated run-off), and (3) such
retrofitting would disrupt existing solid
waste management activities.
Retrofitting may be particularly
disruptive if :a large "number of existing
facilities are found to be unable to meet
the design goal . ,.
The final coyer requirement for
existing units could be met by a wide
range of designs based on site-specific
conditions. These designs range from a
cap consisting of soils with adequate
moisture-holding capacity, planted with .
the proper vegetative cover to handle- -
.the wettest month at this location and
sloped to maximize surface run-off:
withoat causing significant erosion ,
problems, to a cap containing a
hydraulic barrier, such as a flexible
membrane liner to prevent infiltration
into the waste. •'•.'.-..
As 'with new units, many factors are
involved.in designing the final cover.
These include precipitation, potential
and actual evapotranspiration soil
moistae holding capacity, vegetation,
and run-off. There are several
methodologies available that use these
iactors to estimate the amount of
infiltration that may enter the waste.
These methods are discussed in the
background documents that support
today's rule (Ref. 5).
2. Rationale for Proposed Approach
The: primary goals of this rule are to
establish standards that are protective
of human health and the environment,
provide flexibility to the States, and
minimize disruption of current solid
waste management practices by -
considering the practicable capability of
the regulated community. The Agency
believes.that a performance standard
approach for the design of MSWLF units
best ensures that these goals can be
achieved.
Today's proposed requirements would
allow the owner or operator to,take into
accoDint site-specific conditions when
designing the unit to ensure that the
concentration of contaminants at a
specified compliance point (e.g., the
waste management unit boundary)
meetii the design goal. Furthermore,, use
of a performance standard allows for
the consideration of innovative
technologies that may be developed in
the future.
Today's performance standard would
also provide States the flexibility to
'make the final decision as to how. the . •
standard would be achieved. Many
States currently have standards that
utilize a performance s.tandard approach
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
for design of MSWLFs and strongly
support the performance standard
approach proposed today. The Agency
believes that, In many cases, only minor
modifications to existing State
standards would be necessary to make
thorn consistent with today's proposal.
rherefore, EPA believes that the
proposed standard allows consideration
of practicable capability and will result
in minimal disruption to State programs.
A review of current State regulations is
included in background documents
supporting this proposal (Ref. 9).
a. Differences from Existing Part 257
Criteria. Today's proposed standard for
MSWLFs is similar to the current
requirements under 40 CFR 257.3-4,
which prohibits Subtitle D facilities from
contaminating ground water beyond the
solid waste boundary or an alternative
boundary specified by the State. There
are, however, several major differences
in today's proposal.
First, today's proposal specifically
would require the owner or operator to
design new units to meet a protective
ground water risk level. (See discussion
in Section IXD.l.a. of today's preamble
concerning the design goal and EPA's
request for comment on alternative risk
ranges.) Under the existing Criteria, if a
facility contaminates the ground water,
the facility is classified as an "open
dump" and must be upgraded or closed
under a State-approved compliance
schedule. Today's proposal, by
establishing a design goal tied to
ground-water protection, is intended to
Be preventive rather than reactive.
Second, the proposed design goal is
an overall risk level that encompasses
risks from a comprehensive set of
constituents (i,e., Appendix II), which
form the basis of the ground-water
protection standard. The standard for
the existing Criteria is limited to the
contaminants Identified in the National
Interim Primary Drinking Water
Regulations (NIPDWRs), now National
Primary Drinking Water Regulations
(NPDWRs). The Agency recognized in
the preamble when it promulgated the
existing Part 257 Criteria that this list
did not serve as a comprehensive
ground-water quality standard because
it did not include all potentially harmful
substances that might be associated
with leachate from solid waste. Today's
proposal requires that an overall risk
level (i.e., design goal) be selected and
used in new unit design and that, during
ground-water monitoring, a more
comprehensive list of constituents (i.e.,
more comprehensive than the existing
Part 257 Criteria) be used to ensure that
the design goal is being met. This list
includes many constituents that may be
found in landfill leachate, thereby
providing more protection to human
health and the environment than the
existing Criteria. This proposal is
' discussed in greater detail in Section
IX.E of today's preamble.
Third, EPA is proposing to establish a
maximum limit on the distance the
alternative boundary may be from the
waste management unit boundary.
Under the original Criteria, the
maximum limit for the alternative
boundary was left to the State's
discretion. The Agency has chosen to
propose a limit of 150 meters from the
unit boundary in establishing the '
alternative boundary. The site-specific
factors to be used in establishing ail
alternative boundary that were
identified in the original Criteria,
however, have been maintained.
Fourth, today's action proposes
ground-water monitoring and corrective
action requirements for both new and
existing municipal waste landfills. The
monitoring requirements would allow
continuous evaluation of whether
facilities are complying with the design
goal, while the corrective action
requirements ensure that appropriate
responses are taken to protect public
health from exposure to contaminated
ground water and minimize resource
damage.
Finally, today's action proposes
different design standards for new and
existing MSWLF units, unlike the
original Criteria, which established one
design standard for both types of units.
EPA made this decision for the reasons
discussed earlier (e.g., practicable
capability); however, when this different
standard for existing units is considered
in context with other requirements of
the proposal (e.g., corrective action), the
overall protection is the same.
b. Differences From Subtitle C
Standard. There are two major
differences between the current Subtitle
C standards for hazardous waste
landfills and today's proposal. First, the
overall performance standard for the
design of hazardous waste landfills is
more stringent than the performance
standard for MSWLFs. Subtitle C
landfills must be designed to prevent
hazardous waste or hazardous
constituents from entering the
surrounding soils and ground water. The
proposed performance standard for
MSWLFs, which would require that the
design goal not be exceeded at the
compliance point, allows the mitigating
effects of the surrounding soils and
aquifer material to reduce the
concentrations of contaminants. The
Agency believes today's standard is
appropriate for MSWLFs because it
allows for consideration of the
practicable capability of the regulate>
community.
The second major difference between
toady's proposal and the current Subtitle
C standards is the strict Subtitle C
design standard. Although there are
certain very stringent variances
available, location characteristics (e.g.,
climate and hydrogeology) generally do
not reduce the design requirements for
Subtitle C facilities as they do under the
Subtitle D proposal. Therefore, Subtitle
C specifies one design (i.e., double
liners, LCSs, and leak detection
systems) for almost all locations, while
the proposed Subtitle D performance
standard would allow location
characteristics to be considered when
designing the MSWLF unit so that the
location and design of the unit
complement each other. This proposed
standard would allow consideration of
the practicable capability of the owner
or operator.
3. Alternatives Considered
The Agency considered a number of
alternatives to the design requirements
proposed today. Various performance
standards, uniform design standards
(with and without variance provisions),
location categories approach, and risk-
based approach were considered in
developing today's design requirements.
The Agency requests comments on all
the alternatives presented below. EPA
specifically is interested in comments on
the advantages and disadvantages of
the alternatives in relation to today's
proposed approach.
a. Other Performance Standards. EPA
considered two alternative performance
standards to those contained in today's
proposal: (1) Require MSWLFs to be .
designed to meet the design goal at the
unit boundary but make no allowance
for an alternative boundary and (2)
require MSWLFs to be designed to meet
the design goal at the unit boundary or
any alternative boundary specified by
the State (current standard in 40 CFR
Part 257). These alternatives were
evaluated based on the potential extent
of ground-water contamination that may
result, ability to enforce the standard
through citizen suits, the practicable
capability for the regulated community
to comply, and flexibility afforded the
States.
The first alternative, requiring
MSWLFs to meet the design goal at the
unit boundary, would provide the
greatest protection to ground water
because, by strictly defining the point of
compliance as the unit boundary with
no alternative allowed, it limits the real
extent of ground-water contamination.
-------
This alternative could be enforced easily
through citizen suits; however,- this
option does not allow consideration of
the practicable capabilities of the
regulated community and could limit
State flexibility by not allowing States
to consider site-specific.conditions when-
determining the point of compliance.
Further, by not allowing consideration
of site-specific conditions, this
"alternative could result in over-
regulation and could exceed the
practicable capability of the regulated
community to comply.
The second alternative, requiring
MSWLFs to meet the design goal at the
unit boundary or a State-selected
alternative, would provide more
flexibility to account for the practical
capability of the regulated community. It
would be less burdensome to the
regulated community because site-
specific factors could be considered,
thereby avoiding over-regulation and
increased costs; however, it would be
less protective of ground water because
it would allow for a greater area extent
of ground water to be contaminated
than the first alternative. This
alternative also could be difficult to
enforce through citizen suits because no
one alternative boundary .would be
specified in the rale for all MSWLFs. .
The Agency believes that today's
proposal provides a balance of the
positive aspects of the above
, alternatives. It limits the potential area
extent of ground-water contamination
by placing a distance cap on. the
alternative boundary.'In addition, it
provides State flexibility, minimizes the
potential for over-regulation, and
considers the practicable capability of
the regulated community. Finally, it
would be enforceable ,at the Federal
level or thrpugh citizen suits because it
would set limits at the point of
compliance.
b. Uniform Design Standards. The,
Agency also considered establishing
uniform design standards for MSWLFs.
Under this approach, requirements for
liners, LCSs, and final cover systems
would have been delineated in the
regulation and would have been the
same for all units. This approach is the
same as that used in the Subtitle C
regulations. This approach can simplify
permitting because the same specific
design requirement applies tp all units
regardless of site-specific differences.
The Agency rejected this type of
.standard for MSWLFs because it would .
not consider site-specific location
• factors nor the practicable capability of
the regulated community to comply,
resulting in possible over-regulation in
some areas. Further, it would severely
limit State flexibility,
The Agency also considered uniform ;
design standards with variances to
allow variation of designs based on site-
specific,factors. In particular, the
Agency considered proposing for all
new MSWLFs composite liner and
leachate collection system requirements
similar to those proposed today only for-,.
those MSWLFs that recirculate leachate
or gas condensate. As stated previously,
the composite liner system would
consist of a flexible membrane liner as
the upper component and a compacted
soil layer as the lower component. The
soil layer would be at least three-feet, ~
thick with a hydraulic conductivity of no
more than 1X10~7 cm/sec. The leachate
collection system would need to be
constructed to maintain less than a 30-
cm depth of leachate over the liner. A
variance mechanism would be provided
to allow use of alternative designs
based on site-specific considerations.
These variances would be based on the
hydrogeological characteristics of the
landfill, alternative operating methods,
the resource value of ground.water, the
nature of the alternative design, and
other factors. The combination of these
factors would have to provide a level of
environmental protection equal to the ...
standard design. ,.
The Agency recognizes that this
approach would likely be easier to
implement and enforce and may provide
greater assurance of protection of
human health and the environment than
other options considered; EPA is not
proposing this approach because of
concern regarding the difficulty hi
granting variances and the resulting
potential over-regulation of some
facilities. The Agency also is concerned
that this approach would limit the - -.
States' ability to adequately consider
the practicable capability of the
regulated community.
c. Risk-Based Algorithm, The use of a
risk-based algorithm is based on the
development of a predictive equation
that can be used to determine, on a site-
specific basis, the potential human
health risks from a proposed landfill.
Such an approach could be simple to
implement and could incorporate a large
number of site-specific factors; however,
the development of a valid predictive
equation is difficult and its reliability
would be limited by the quality of data
employed in it. Furthermore, one
equation may not be appropriate for all
site-specific situations. .
d. Categorical.Approach, Another
alternative considered by EPA; which is
described in detail in the next section of
this preamble, is ah approach that
would categorize locations based on
hydrogeologic and climatic conditions.
Specific designs would be identified for*
each category, and methods for
categorizing locations and their
corresponding requirements would be .
specified. This approach.would be
relatively easy to implement and would
allow the consideration of site-specific
conditions. The approach allows the
consideration of climatic factors and .
geologic conditions, but no aquifer
characteristics and ground-water
resource value. Also, this approach
might not adequately account for the
practicable capability of the regulated
facilities to comply. In addition, this
approach would restrict State flexibility
by prescribing a methodology States
would use hi establishing design-; .
requirements for various locations,
While EPA has not proposed this
approach today, EPA also is presenting
this approach, along with the risk
algorithm, as possible methods for
deterniining adequate designs for
meeting the performance standard
proposed in § 258.40(a).
The. Agency recognizes that the choice
of a particular type of standard is a very
controversial decision and is interested
in obtaining public comment on today's
selection. The selection was based on
an attempt to balance several factors
including the practicable capability of
the related community to comply,
States flexibility in implementing
Subtitle D regulatory programs, and
Federal or citizen suit enforceability.
Commentors may wish to consider
additional factors when providing
comment and/or submit other factors for
EPA's consideration. ,
4. Implementation of Performance
Standard for New Units
Today's proposal would require that
' new MSWLF units be designed with
liners, LCSs, and final cover systems as
, necessary to meet the performance
standard described above. The specific
type of design needed Would vary
depending on the characteristics of the
particular location. In some settings,
comprehensive liners and LCSs would
be nee:ded, whereas in other settings,
minimal engineering controls may be
needed. This section provides a brief
background on engineering controls and
describes various methods for
determining the landfill design
• necessary to achieve today's proposed
performance standard.
a. Overview of Engineering Controls.
The purpose of lining an MSWLF unit is
to prevent leachate from seeping from
the site and entering the aquifer. A liner
is a hydraulic barrier that prevents or
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33356
Federal Register / ', ol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rulus
greatly restricts migration of liquids,
thus allowing leachate to be removed
from the unit by the LCS. Liners function
by two mechanisms: (1) They impede
the flow of leachates into the subsoil
and to the aquifer and (2) they adsorb or
attenuate pollutants thus retarding the
migration of contaminants. This
adsorptive or attenuating capability is
dependent largely upon the chemical
compositions of the liner material and
its mass. Most liner materials function
by both mechanisms but to different
degrees depending on the type of liner
material and the nature of the liquid to
be contained. Liners may be grouped
into two major types: synthetic (flexible
membrane liners) and natural (soil or
clay liners).
Flexible membrane liners are the least
permeable of the liner materials, but
have little capacity to attenuate
dissolved pollutants. Natural liners can
have a large capacity to attenuate
materials of different types, but they are
considerably more permeable than the
EMLs. Both types of liner materials can
prevent or limit leachate migration out
oftheMSWLF.
A review of the MSWLF case studies
identified various types of liners
currently being used, including
compacted native and imported soils,
compacted mixtures of native soils and
bentonite, and FMLs. The liner designs
used varied somewhat from region to
region.
In landfills designed with liners, a
leachate collection and removal system
is necessary to relieve the hydraulic
pressure within the landfill. Without a
collection and removal system, the
leachate will accumulate, increasing the
driving force for migration through the
base of the fill. Leachate could
eventually back up into the unit (i.e., the
"bathtub" effect), resulting in seepage
near the surface and possibly affecting
surface waters or other receptors.
Collection systems also may be needed
when a landfill is located in saturated
soils. Water from this saturated material
eventually will seep into the waste and
generate leachate if not removed by an
LCS.
The collection and removal of
leachate from the unit will assist in
meeting the overall performance goal for
the unit. An LCS generally consists of
perforated drain pipe installed in gravel-
filled trenches above the liner at the
base of the unit The collection system is
drained by gravity to a sump or series of
sumps from which the leachate is
withdrawn for treatment or disposal.
Additional details on the design and
construction of LCSs can be found in
"Lining of Waste Impoundment and
Disposal Facilities" (Ref. 36).
. The Agency believes that placement
of a final cover over closed portions'of
an MSWLF is necessary to: (1) Minimize
infiltration of rainwater; (2) minimize
dispersal of wastes by human, animal,
or physical interactions; and (3)
minimize the need for further
maintenance at the facility during the
post-closure period and beyond. The
types and amounts of cover material
needed to accomplish these goals and to
achieve compliance with the design goal
are highly dependent on the location of
the landfill. The amount of infiltration of
water into the final cover and any
subsequent percolation through the
waste can be affected by surface
conditions such as soil type, soil
thickness, final grade, type of
vegetation, and climatic factors such as
amount of precipitation, temperature,
and evapotranspiration. For example, in
areas with limited rainfall and high
evapotranspiration, minimizing
infiltration may be achieved by: (1)
Grading the unit in such a way as to
promote run-off, (2) using the proper
type and thickness of soil to maximize
moisture-holding capacity, and (3)
establishing vegetation to promote plant
transpiration of water. In areas of high
rainfall and low evapotranspiration,
these design factors may not
substantially reduce the amount of
. water entering the waste after closure.
In such cases, additional design factors,
such as hydraulic barriers, either
synthetic or compacted soils, and/or
drainage layers, may be required in the
final cover to reduce infiltration to
acceptable levels. Further information
on the design of cover systems is
available in a background document
(Ref. 5).
b. Methods for Evaluating Designs.
Today's proposal does not prescribe a
single method for designing a facility to
meet the performance standard. Because
the Subtitle D program is implemented
by the States, the Agency believes that
the appropriate method for
implementing the design performance
standard is best determined by the
States; however, EPA is providing
guidance on three methods for
determining what design is necessary to
comply with the performance standard
(i.e., to meet the design goal at the point
of compliance). These methods include:
(1) A risk-based algorithm, (2) a
categorical approach, and (3) an
empirical method. A fourth method not
discussed involves using a State-
selected risk model. Although this last
method is not described, the data
needed and assumptions made for the
risk-based algorithm may be similar to
what would be necessary for the State-
selected risk model
For the risk-based algorithm (and the
State-selected risk model), the design
goal is expressed as a risk level. The
risk level selected as the design goal is
not directly involved in applying the
categorical approach but is used to
determine compliance and to establish
clean-up levels for corrective action. The
categorical approach presented today is
based on preventing any leachate from
migrating to the aquifer. Because of this
no-migration concept, this approach is
generally more conservative than the
risk-based algorithm and in some cases
would require more extensive
engineering controls than would be
determined from the risk-based
algorithm.
The empirical methodology uses
historical ground-water monitoring data
to assess the effectiveness of existing
designs in meeting the design goal.
The ground-water monitoring data
would be used to calculate a risk level
that would be compared to the design
goal.
These three methods are described
below and in more detail in the
background document on facility design
(Ref. 5). EPA plans to issue a guidance
document addressing facility design
after the final rule is promulgated.
(1) Risk-Based Algorithm. Using the
Subtitle D Risk Model, EPA derived an
algorithm that characterizes a site's
potential for ground-water
contamination. This algorithm uses
information on a facility's potential
leachate release rate and the
characteristics of the site's hydrogeology
,,to estimate the level of ground-water
contamination that would result from an
MSWLF operating at that site. The level
of contamination is represented in the
algorithm by the excess lifetime cancer
risk associated with human
consumption of ground water at the
landfill's compliance point. States and
landfill owners or operators can use this
algorithm as a screening tool to
determine whether a new MSWLF at a
given site is likely to achieve
compliance with the State-established
design goal if constructed with no
' bottom liner and a vegetative cover. The
risk-based algorithm cannot be'used to
analyze the reduction in human health
risks that would be achieved through the
use of more stringent control
technologies.
The steps involved in using the risk-
based algorithm are displayed in Figure
1. The'State would establish the design
goal that is tied to the trigger levels for
hazardous constituents specified in
§ 258.56 for the landfill. If the calculated
risk is lower than the design goal, this
would imply that the proposed landfill
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 fl Proposed Rules
33357
would be in compliance with the ..
performance standard. If the calculated
risk exceeds the design goal, the owner
or operator could choose a new site for
the landfill, change the proposed -'•-.
dimensions of the landfill, or employ
more stringent control systems (e.g.,
bottom liners, leachate collection
systems, different cover types). The
effects of changes invocation on risk
potential could be calculated using the
risk-based algorithm, while the effects of
more stringent containment and cover
systems could not. EPA recommends
that'a more rigorous State-selected
assessment (either risk- or technology
based) be used to specify the mix of
containment and cover system
components capable of meeting the
design goal. . ,
EiLUMG CODE 6560-50-M
-------
FIGURE 1
APPLICATION OF RISK-BASED ALGORITHM
CO
CO
CO
§3
1. DETERMINE SITE AND DESIGN CHARACTERISITCS
NECESSARY TO ESTIMATE THE 3 ALGORITHM
VARIABLES
2. ESTIMATE VALUES FOR THE 3 ALGORITHM VARIABLES
AND USE ALGORITHM TO COMPUTE RISK LEVEL
3a. CALCULATED RISK MEETS STATE-
ESTABLISHED DESIGN GOAL
-- PROPOSED FACILITY OR
FACILITY EXPANSION IS
UNLIKELY TO CONTAMINATE
GROUND WATER ABOVE THE
DESIGN GOAL
-- NO ADDITIONAL CONTROLS ARE
NEEDED
3b. CALCULATED RISK FAILS TO MEET
STATE-ESTABLISHED DESIGN
GOAL
-- PROPOSED FACILITY OR FACILITY
EXPANSION WILL LIKEY
COMTAMINATE GROUND WATER
ABOVE THE DEG1N GOAL
-- ADDITIONAL CONTROLS ARE
NEEDED
» MODIFY LANDFILL SIZE OR
LOCATION AND RETURN TO
STEP1 -OR-
USE A DIFFERENT METHOD TO
DETERMINE NECESSARY CONTROLS
S1
a.
o
S
93
CD
01
CO
3
s-
CO
o
T3
O
CO
•S.
I
w".
CO
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168) Tuesday, August 30, 1988 / Proposed Rules
33359
•The risk-based algorithm is as
follows:
R=4.5 * IO-^QR/QA)* e <«>T> (-0.029
where: ,
R— lifetime risk posed by consumption of
ground water at designated compliance
point.
Qn=predicted leachate release rate to the
uppermost aquifer, ms/yr.
QA=ground-water flow rate for the
uppermost aquifer, ma/yr.
TOT=time-of-travel for leachate in this
aquifer from the unit boundary to the
compliance point, years (TOT=0 for unit
boundary compliance point).
In essence, the risk-based algorithm
states that the risk associated with
ground-water contamination from an
MSWLF is a function of the rate of
leachate release from the site and the
attenuation (i.e., dispersion and
degradation) of this leachate in the
aquifer. QR represents the annual
leachate release rate, while QA and TOT
account for the dilution, dispersion and
degradation of contaminants hi ground
water, Methods for calculating QK, QA,
and TOT are described later.
EPA acknowledges several limitations
of this approach. First, this approach is
dervied by assuming that the MSWLF
risk results produced by the Subtitle D
Risk Model represent "true" risks and
fitting a simplified mathematical model
(i.e., the risk-based algorithm) to these
results. The Subtitle D Risk Model is
currently unverified for predicting
ground-water contamination resulting
from MSWLFs. However, EPA believes
the model is technically correct and
believes that it can adequately
characterize the risk from MSWLFs.
Second, the approach assumes that
the leachate produced from a particular
landfill will have a composition and
constituent concentrations similar to
that used in the Subtitle D Risk Model.
The initial leachate constituent
concentrations used in the model
represent the median concentrations for
six constituents found in samples of
leachate from numerous MSWLFs (see
Section XI of preamble). (A complete
discussion of the leachate constituent
selection process, including the dose-
response parameters used for the
constituents, is contained in the draft
Regulatory Impact Analysis.) The risk-
based algorithm should not be used for
proposed MSWLFs that have expected
leachate characteristics substantially
different from those used in the Subtitle
D Risk Model. EPA recommends that, at
these landfills, a State-selected Risk
Model or other approach be used.
Third, the risk-based algorithm never
predicts risks higher than 4.5X10"4. This
-'alue was derived from the Subtitle D
Risk Model results for approximately
500 distinct combinations of landfill size,
environmental and hydrogeologic
setting, and exposure distance; In about
5 percent of these scenarios, the
modeled risks were higher, although
none exceeded 10~3.
Fourth, although the risk-based
algorithm is relatively powerful in a
statistical sense (i.e., its predicted risks
correlate well to the Subtitle D Risk
Model's predicted risks), its use
introduces some additional uncertainty.
The State might account for some of
the uncertainty in the approach by
setting the risk-based algorithm goal
somewhat lower than the actual design
goal. For instance, if the State
determines that the actual design goal
should be 1X10~", it could state that any
MSWLF with calculated risks exceeding
1X10~6 would be required to perform a
more detailed site-specific assessment.
Such a margin of safety (in this example,
one order-of-magnitude) would allow
the States and owners and operators to
identify low-risk MSWLFs relatively
quickly and focus more effort on
borderline or high-risk MSWLFs. EPA
recommends that the States determine
the acceptable margin of safety between
the risk-based algorithm-predicted risk
and the design goal.
Fifth, the risk-based algorithm does
not apply to sites with complex
hydrogeology. The ground-water
concentrations in sites characterized by
fractured, folded, or faulted rock, karst
terrain, tidally-induced changes in
ground-water flow, or similar complex
conditions are not represented in the
underlying Subtitle D Risk Model, and
thus the risk-based algorithm does not
predict them. In these conditions, EPA '
recommends more sophisticated
analytical techniques be used.
Sixth, characterizing the variables
needed to solve the algorithm for an
individual site may be both costly and
difficult. However, some simple methods
are available to make these
determinations, as discussed later.
These limitations thus relate to the
ease of implementation and the
uncertainty embodied in the approach.
EPA has attempted to propose the risk-
based algorithm in a form that strikes a
reasonable balance between the desire
for accuracy and certainty on the one
hand, and timely, moderate-cost
implementation on the other.
In order to develop the risk-based
algorithm, the Agency identified from
case studies, damage cases, field
observation, Subtitle D risk modeling
results, and other sources several
environmental factors that affect
leachate. generation, leachate release,
migration, exposure, and risk. These
factors include landfill size, net
infiltration; _subgrade permeability,
depth to ground water, aquifer flow rate
and time-of-travel from the unit to a
potential exposure point. Using the list
of key environmental factors, EPA
conducted an analysis of variance
(ANOVA) and a regression analysis.
The ANOVA allowed EPA to determine
the importance of each of the
environmental variables in explaining
the variation in the predicted MSWLF's
risk. The regression analysis, coupled "
with an understanding of the "
physiochemical processes that affect
risk, allowed EPA to establish a simple
equation, using the key environmental
variables identified in the ANOVA, to
predict a facility's risk.
For the purpose of the ANOVA and
regression analysis, EPA used the risks
predicted from the Subtitle D Risk
Model. For this application, the model
simulated approximately 500 exposure
scenarios comprising unique
combinations of infiltration rates,
facility size, depth to water table,
hydrogeologic conditions (aquifer
velocity and configuration), and
exposure point. For each scenario, EPA
predicted the highest lifetime health risk
that would be experienced over a 300-
year simulation period.
,In establishing the importance of the
environmental variables, the Agency
generated a series of ANOVA tables
displaying the relationship between the
identified (independent) environmental
variables and risk, the dependent
variable. The ANOVA tables provided
EPA with a means to evaluate the
strength of the association between risk
and the various independent variables.
The ANOVA results indicated that
none of the environmental variables
alone explains more than 10 percent of
the variability in risk; EPA then
combined some of the related variables
to 'test the relationship between risk and
three "top" parameters: leachate flux
(QR). aquifer flux (QA), and TOT, QRis a
function of several variables including
the facility size, the infiltration rate, and
the subjjrade permeability. QA is a
function of the aquifer velocity (i.e.,
. permeability and hydraulic gradient),
aquifer thickness, and effective porosity.
It accounts for the dilution and
attenuative capacity of the aquifer, and
is measured at the downradient point of
compliance. TOT is a function of the
aquifer velocity and distance to the
downgradient compliance point. Using
these "top" parameters, EPA analyzed
several forms of the equation used to ; ,
predict MSWLF risks.
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33360
Federal Register /
53.
As with moat regression equations,
the chosen algorithm omits some
independent variables that could
increase the explanatory power of the
model; however, EPA believes that it is
better to use fewer variables and keep
the classification scheme simple. EPA
believes that the relationship is
conceptually valid and realistically
depicts the actual physical relationships
between these parameters.
To apply the risk-based algorithm at a
given site, the owner or operator must
calculate three variables: leachate flux
(Qr), aquifer flux (Qa), and ground-
water TOT. Several methods exist for
calculating TOT, QA. and QR. TOT
equals the distance between the landfill
unit boundary and the compliance point;
this distance is then divided by the
ground-water velocity. Thus, TOT will
equal zero whenever a unit boundary
compliance point is selected.
Calculation of ground-water velocity
requires either field measurement or
obtaining estimates of hydraulic
conductivity, hydraulic gradient, and
effective porosity from available
literature. Ground-water velocity equals
Kl/n, where K is the hydraulic.
conductivity, I is the hydraulic gradient,
and n is the effective porosity.
QA also can be determined either by
field measurement or by empirical
calculation. QA equals KIA, where K is
the hydraulic conductivity, I is the
hydraulic gradient, and A is the cross-
sectional are of the aquifer.
Qn can be calculated as the product of
the surface area of the MSWLF and the
annual recharge. The surface area of the
landfill can be taken from site maps and
plans. Recharge can be estimated either
empirically or through use of a water
balance method. EPA recognizes that
this approach of calculating QR does not
account for the potential effects of low-
permeability wastes or subgrades in
limiting the rate at which leachate can
be released from a landfill. In most
cases, the leachate release rate will be
limited by the recharge rather than the
permeability of the waste or the
subgrade.
EPA realizes that the cost of
estimating values for some of these
variables can be high, depending on the
method used. EPA believes, however,
that at least nome of these costs would
be incurred independently of the use of
the algorithm (e.g., hydrogeologic
studies).
EPA requests comments on this
approach, particularly on the utility of
the approach; the difficulty in
implementing it; the leachate
characterization; environmental
transport; this technical accuracy of the
risk-based algorithm; and methods for
addressing the uncertainty inherent
throughout the risk assessment that is
the conceptual foundation for this
approach.
(2) Categorical Approach. The
categorical approach is an engineering
approach for determining whether a
facility will meet the performance
standard and is based on the ability to
match location characteristics to
specific design requirements. The intent
is to present a simplified methodology
that accounts for liquid migration in the
overburden (the material between the .
bottom of the unit and the top of the
aquifer). The categorical approach is
designed to achieve minimal releases to
the aquifer, which is somewhat more
stringent than the performance goal
proposed today (i.e., meet design goal at
unit boundary or alternative boundary).
A relative comparison of the (estimated)
necessary designs, costs, and benefits of
the categorical approach to the proposal
is contained in the draft Regulatory
Impact Analysis.
The approach uses two basic
elements. First, the design selected for
use during the active life, takes into
account local hydrogeologic and
climatic conditions to prevent liquids
from reaching the aquifer. Second, at
closure, a final cover system is used that
minimizes the generation of leachate by
preventing the infiltration of liquid into
. the waste. The Agency recognizes that
the final cover will not stop leachate
from migrating to the aquifer, but the
final cover will minimize the amount of
water that moves through the waste into
the aquifer. .By reducing the amount that
enters the aquifer, EPA believes that the
performance standard^specified in
§ 258.40(a) can be met because the
dilution and attenuation that occurs in
the aquifer will reduce the
concentrations of the small amounts of
contaminants that escape the landfill.
Because the categorical approach
seeks to minimize constituent releases
to aquifers, it is conservative approach
to designing facilities to meet today's
performance standard. The State and
the owner or operator should be aware
of this when using this approach to
identify designs necessary to meet
today's performance standard.
The categorical approach is based on
the potential for contaminants in
leachate to migrate from the MSWLF.
Leachate is formed by rainwater and
other liquids percolating through the
solid waste hi the landfill. Different
hydrogeologic and climatic settings
influence both the rate at which
leachate is generated and the potential
for leachate to escape from the unit and
eventually reach ground water. Under
this approach, location categories are
established based on the migration
potential of water from the landfill unit.
Once the location categories are
defined, design requirements are
specified to offset the effects of "poor"
locational factors to counteract the
rapid movement of contaminants from
the MSWLF to the aquifer that these
"poor" locations promote.
Under this approach, locations are
categorized based on the climate and
geology, which determine the potential
for contaminants to migrate into the
aquifer. In developing this approach,
climate and geology were evaluated to
determine their contribution and
importance to the generation and
migration of leachate from landfills.
Because this approach is based on
preventing the migration of leachate to
the aquifer during the active life of the
unit, aquifer characteristics do not play
a role in the selection of design.
requirements necessary to meet the
design standard.
(a) Climatic Factors. The Agency
believes that climatic conditions are key'
factors in determining the rate and
amount of leachate that will be
generated in an MSWLF unit. The
climate of a particular area is dependent.
upon the interrelationships of numerous
conditions. The factors that the Agency
evaluated in developing the categorical
approach are: Precipitation, potential
evaporation, potential
evapotranspiration, temperature, and
run-off. Each factor is discussed briefly
below.
Precipitation normally is expressed as
the amount of rainfall and snowfall that
occurs at a specific location.
Precipitation is the primary climatic
factor affecting the generation of
leachate at landfills. When precipitation
enters a landfill, it infiltrates the wastes
and dissolves contaminants to form
leachate. As more leachate is formed,
hydraulic head is built up at the base of
the landfull that acts as a driving force
for. migration to the subsurface. Both the
rate and degree to which this process
occurs will vary, based on the location
of the MSWLF.
Potential evaporation (PE), measured
as pan evaporation, is normally
expressed as the amount of water that
potentially will evaporate from a free
water surface at a specific location. This
factor often is similar to lake
evaporation and is not representative of
MSWLF conditions. Potential
evapotranspiration (PET) is normally
expressed as the potential amount of
water that will evaporate from soil
surfaces and transpire through plants at
a given area. Normally, PET is lower
than PE in a given area/Temperature
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Federal egfeter / Vol. 53, No.
plays an important role in potential
evaporation and potential
evapotranspiration for a given location;
-the values for these factors incorporate
the effects of temperature.
Run-off, although not a climatic factor,
normally is expressed as the amount of
water that will migrate from the site in
the form of overland flow. Major land
surface conditions affecting surface run-
off include topography, cover material,
vegetation, soil permeability, antecedent
soil 'moisture, and artificial drainage.
In order to achieve the overall goal of
this methodology (preventing leachate
from reaching the aquifer during the
active life of the unit), it is necessary to
determine the factor or factors that best
represent the potential amount of
moisture available for entering the
waste, thereby generating leachate. The
Agency evaluated the above factors to
determine which factor or factors best,
characterized the climatic elements
relevant to leachate generation. The
objective of the evaluation was.to
determine the potential for leachate
generation during the active life of a
unit. As stated earlier, the Agency
believes that once the MSWLF is
properly closed and covered, leachate .
generation should be minimal. No single
factor or combination of factors could
be found that adequately characterized
climatic elements such that leachate
generation during the active life could
be estimated. EPA, -therefore, selected a
simple two-step proqess that can be
used to categorize locations based on
climate. This process uses mean annual
' precipitation as the factor in the first
step.
The first step of the propess. requires
that the mean annual precipitation (P)
for an area be determined. P was chosen
because: (1) It is easily determined, (2) it
does not necessarily require the
collection of new data, and (3) it
conservatively describes the amount of
water potentially available for
infiltration and leachate generation;
Using P conservatively estimates' the
amount of leachate formed because it
does not consider evaporation or run-
off. Values of P can be obtained from
the National Weather Service, the
National Oceanographic arid
Atmospheric Administration (NOAA),
and/or USGS Water Atlases. These
sources have collected rainfall data over
extended periods of time, so values from
these sources should be representative
. of annual rainfall in an area.
The Agency believes that there is a
relationship between precipitation and
leachate generation. Based on an
evaluation of MSWLFs in different
climatic settings, EPA has concluded
that areas that receive more than 40
inches or precipitation per year generate
leachate in quantities sufficient to
warrant collection. Therefore, under the
categorical approach, units located in
areas that receive more than 40 inches
of precipitation annually would be
required to have leachate collection. For,
areas that receive less than 40 inches of
precipitation per year, the evaluation
indicates that leachate may not always
. be generated in amounts necessitating
collection. Therefore, the second step of
the process is to estimate the amount of
leachate formed in areas receiving less
than 40 inches of precipitation to
determine if enough leachate is
generated to warrant'collection.
This estimate incorporates factors
that determine the potential for leachate
accumulation at a specific landfill. The
• factors used include P, PET, actual
•evapotranspiration, soil moisture ;
holding capacity, waste moisture
holding capacity, and run-off. Because
MSWLFs are ongoing construction
projects, the relationship among these
factors relative to leachate
accumulation continually changes.
Therefore, a demonstration.method that
evaluates the potential amount of
leachate accumulation at different
stages of landfill .construction is
necessary. Under this method, the
evaluation would be based on the
projected landfill configuration at the
end of each operating year. The Agency
believes that some facilities in low
precipitation locations may be able to
eliminate the need for leachate
collection by adjusting operational-
characteristics of the site.
The following steps are needed to
determine when an LGS is necessary:
Step 1: Estimate topographic contours
of the unit at the end of each operating
year throughout the active life until final
cover has been installed.
Step 2: Compute the quantity of
leachate generated for each year of
active life using the water balance
method. This step may require dividing
the landfill unit into discrete areas to
take into account differing grades and
variations in surface run-off. If so
desired, the moisture-holding capability
of soil layers used for cover could be
considered.-Most active portions of a
landfull will have no vegetative cover,
so moisture loss by evapotranspiration
should not be considered in the water
balance calculation. Moisture loss from
active portions should be accounted for
by using estimates of evaporation from
bare soil as described in an-EPA
guidance document (Ref. 35). .
Step 3: Calculate the total
accumulation of leachate at the base of
the unit by adding the amount of ;
leachate generated to the amount
predicted for each previous year.
: Step 4: If total accumulation of
leachate at the base of the unit (as
determiried by Step 3) exceeds or equals
one foot at any stage of the landfill
construction, an LCS is necessary. For
example, for a unit that has a three-year -
active life: for year one, it is estimated
that one foot of field capacity of the
waste remains and no leachate is
generated. For year two, it is determined
that oiiie foot of field capacity remains
and, again, no leachate is generated.
However, for year three, before final
coveV is installed, it is determined that
field capacity for the portion of unit
planned to be built that year will be
exceeded and four feet of leachate will
be generated. Presuming that the year
three piortion of the unit is on top of the
year two and year "one portions of the
unit, the total effect will be to negate the
. unused moisture holding capacity of the
previous two years and result in a head
build-up of two feet at the base of the
unit, which is sufficient to require the
installation of an LCS. This method is
furthei; discussed in the backgound
document supporting this proposal (Ref.
s)- / ''.: :,-.•"-. "• .-.'•".."•• '••;•.•"-":•
(b) Geologic Factors. The nature and
extent of the geologic material ."
underlying a given MSWLF site strongly
influence the fate of any leachate
generated. The qategorical approach
estimates the effects of various geologic
materials based on the time it takes ,
water to move through the material
above the aquifer. Because leachate is
an aqueous solution EPA believes it is
reasonable to model water movement
rather than leachate movement in the
subsurface. The Agency believes this
simplifying assumption is conservative.
This simplified approach does not
include consideration of the variability
of MSWLF leachate over time. Also
spme factors that retard constituent
movement, such as absorption, chemical
precipitation, degradation, and ~
• attenuation, that can result in slower
movement of the constituent than the
solute (i.e., water) are not a part of this
simplified approach. Therefore, the
Agency believes that considering only
the rate of liquid movement is a .'. . . "
.conservative approach. . . "
Certain geologic characteristics
control the rate at which leachate will :••-,
migrate to the aquifieir. For the ' ,
categorical approach, the rate must be
determined so that design features can
be added when the natural conditions
do not give adequate protection to the
aquifier. The geologic factors evaluated
included the following: Depth, saturated.
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33362
Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
hydraulic conductivity, effective
porosity, and linear velocity.
Depth (D) refers to the thickness of
the geologic material between the
bottom of the unit and the top of the
aquifier. This zone is referred to as the
overburden. Saturated hydraulic
conductivity (Ksat) is a measure of the
ability of porous media (soils or rock) to
transmit liquids under saturated
conditions. Effective porosity (N.) is a
measure of the interconnected pore
space in the geologic material. Porosity
has a controlling influence on the linear
velocity of water in the overburden
media. Linear velocity (V) is the spejed
at which ground water travels in the
subsurface under saturated conditions.
Different methodologies were
evaluated that could be used to estimate
the time for liquids to migrate through
the overburden to the aquifier, known as
Umo of travel (T) to the aquifer. The
methodologies involve: (1) Calculation
of T based on a detailed time-of-travel
measurement through the overburden
(for saturated and unsaturated geologic
material) using the approaches
prescribed for determining vulnerable
hydrogeology under Subtitle C (Ref. 11),
(2) calculation based on Darcy's law,
expressed as T=D/Ksat, (3) calculation
to Te*D/V (based on the linear velocity
of water in the overburden with an
assumed hydraulic gradient of one), and
(4) a welting front approach for
unsaturated soil only.
The detailed time-of-travel analysis
results in the most accurate prediction
of when leachate may reach the aquifer
under ideal conditions; however, it is
very data-intensive and complex,
particularly for unsaturated conditions.
It also requires the development of flow
nets.
The second and third methods are
more straightforward because the
necessary data are readily available
from literature and field tests. Because
of their simplicity, these methods could
be used to pre-screen locations with
data available from the literature. These
data should be verified by field tests
prior to site design because field
verification is necessary to ensure that
site-specific conditions match conditions
predicted by the literature.
D-Ksat is the simpler method to use
because it needs only two easily
obtained pieces of data: Saturated
hydraulic conductivity and depth.
Numerous methods are available for
determining saturated hydraulic
conductivity, For example, in fractured
consolidated rock, pressure tests or
falling head tests can be used to
evaluate Ksat. In unconsolidated
materials, constant head gravity tests
are commonly used. These and other
methods are available and documented.
It is important, however, to ensure that
the proper methods are used in the
material being evaluated. Depth may be
obtained easily from a preliminary
subsurface exploratory program and/or
from boring and drilling logs from
surrounding areas.
The third method, D/V, is believed to
be more accurate than the second
method because the velocity (V)
incorporates effective porosity (NJ in
the calculation. As mentioned above,
effective porosity is a measure of the
interconnected pore space in geologic
material. It can be an important
controlling influence on hydraulic
conductivity (and thus rate of flow) hi
both unconsolidated and consolidated
formations. Porosity values range from 0
to 5 percent for dense crystalline rock,
25 to 40 percent for gravel, and 40 to 70
percent for clay. In fractured rock,
secondary porosity also must be
considered. When determining the
porosity of the overburden.at a specific
site, both primary and secondary
porosity should be considered as
warrented.
Although more accurate than D/Ksat,
the D/V method has some features that
make it less accurate than the detailed
time-of-travel calculation discussed
earlier. First, it assumes that the
hydraulic gradient (a major influence on
'ground-water velocity) is equal to one.
This assumption will result in a
conservative time-of-travel value (i.e.,
the actual time may be longer). Second,-
it assumed fully saturated conditions,
which in most cases will result in a
conservative value.
The fourth method involves a wetting
front equation .and may be a better
predictor of flow hi the unsaturated
zone. The method requires the collection
of more data than either the second or
third method. This method is based on
equations developed for infiltration of
water into dry soil and applies
simplifying assumptions to calculate the
time of travel. The equation used to
calculate the time of travel is given as:
T=(LWr)/q
where:
T=time of travel (T).
L=length of the unsaturated zone (L).
Wr=change in moisture content from soil
behind the wetting front to dry soil
ahead of the wetting front.
q=infiltration rate (L/T).
The length of the unsaturated zone (L)
can be determined from boring logs and t
piezometer measurements. Moisture
content behind and ahead of the wetting
front can be calculated, and, therefore,
Wr can be determined from field
measurements or estimated from
empirical equations. The infiltration rate
is (q) approximated by using the net
precipitation.
The principle assumption of this
approach is that there exists a distinct
and definable wetting front, and tha*
behind the wetting front the soil is
uniformly wet and of constant
conductivity. The wetting front
approach is applicable for a limited
range of conditions. In particular, the
approach is useful when a constant
water flux is applied to initially dry soil.
The approach may not be applicable for
soils that are initially moist or that are
uniform hi moisture content under
natural infiltration conditions. The
principle value of the approach is in
predicting unsaturated flow.
The Agency believes that the D/V
method of calculating T is conservative
and easy to calculate. The categorical
approach assumes saturated flow
because the available methodologies
that can be used to estimate the flow
time of water through unsaturated
materials are complex and require
extensive data collection. Calculating
the time of flow for saturated materials
involves less complex equations and
requires fewer resources to obtain the
required data inputs. Furthermore, the
use of saturated conditions is generally
conservative hi predicting time-of-travel
hi the overburden because, for the most
part, K values increase as soil moisture
content increases for a given soil type.
The Agency recognizes that hi certain
unsaturated soils, particularly clays,
saturation may not be a conservative
assumption. Initial breakthrough of
leachate, in small amounts, may occur
prior to the prediction, assuming
' saturation. For the purpose of
categorization, FJPA believes that it is
more important to predict when a major
amount of leachate may enter the
aquifer. However, the owner or operator
has the option of using an alternative
method, including the detailed Subtitle C
time-of-travel calculation or the wetting
front approach.
Under this simplified approach (D/V
method), the value selected for T can be
used to determine which locations
require liners and the type of liner that
may be required. The methodology is
based on the active life of the unit; A
value of T equal to or greater than the
active life of the MSWLF unit is classed
as "long" and a T less than the active
life as "short." A minimum cut-off value
for T of 20 years has been selected
because a minimum T precludes the
siting of short duration units in
relatively poor locations. This minhnum
value of 20 years for T was chosen
' because the average active life of a
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Federal Register / Vol. 53»No./l&B, Tuesdgy,.August 30, 1988
Proposed Eulea
3SS63
facility is approximately 30 years, and a
facility usually consists of more than
one unit. EPA therefore selected 20-
years as the average life of a unit. T
values that are long when compared to
the active life of the unit would not need
liner systems, while units with T values
shorter than the active life^of that unit
would need liners.
: The T value should be determined for
each unit rather than for an entire
facility. For example, an MSWLF may
have a total life of 50 years but comprise
several units with active lives less than
50 years each. The T for each of these
units is a separate calculation. :
(c) Relationship to Design
Requirements, Combining P and T
values results in a matrix comprising
four blocks that correspond to separate
categories, as shown in Figure 2. Each
location category describes a
hydrogeologic and climatic setting with
unique characteristics that affect landfill
design. For example,, Category I has both
good climatic (characteristics jfor a
. landfill (limited precipitation indicated
by the low P) and good hydrogeology
(ace eptable overburden characteristics
evid enced'by TiighT value). On the other
hand, Category IV represents locations
wit! poor climate and hydrogeology that
reqiiire specific landfill designs (liners
and LCSs) to compensate for the poor ,
loca tional characteristics. The two key
.measures of precipitation and time-of-,
travel to the aquifer are .used not only to
establish the location categories, but to
idei tify the landfill design requirements
needed for,a particular location.
BIULIIMQ CODE B560-50-M
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FIGURE 2
CATEGORICAL APPROACH
CO
ta
w
vo
ui
in./yr.
PRECIPITATION
(P)
< 40 irc./yr.
IV
* LCS required
• Liner required
LCS not required unless
need demonstrated
Liner required
< Active Life*
LCS required
Liner not required unless
needed for LCS
• LCS not required unless
need demonstrated
Liner not required unless
needed for LCS
TIME .OF TRAVEL TO AQUIFER
• MINIMUM I VALUE 85 20 YEARS
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Au§ust 30, 1988 /lProposed Rules
33365
In Categories I and III, the low P value
indicates that the potential for leachate
generation is less than in Categories II
andTV. This low potential is not to
imply that leachate will not be
generated in quantities sufficient to
warrant a collection system at facilities
in low P areas. The demonstration
described earlier to determine if an LCS
is necessary should be conducted.
In Categories n and IV, high P values
indicate that climatic conditions are
conducive to the continual generation of
( leachate. Leachate control, therefore, is
necessary in order to prevent the
buildup pf a hydraulic head within the
unit during the active life of the facility.
Any leachate generated after the active
life of the unit also must be collected. .
In addition, the Agency believes that
LCSs are necessary when flexible
membrane liners are installed. FMLs are
very efficient hydraulic barriers, and an
LCS is necessary to remove the
hydraulic head that accumulates over
time. FMLs installed without such
systems will ultimately result in the
"bathtub" effect. ,-
Facilities sited in Category I and II
locations have overburdens that already
satisfy the requirements that T at least
equals the active life of the unit.
Therefore, modifications to the
overburden would not be necessary at
these sites. Some Category I and H
locations, however, may need a liner if
they need an LCS and if the natural
overburden material does not have a
permeability low enough to allow the
LCS to properly function. For example, a
site may have an adequate thickness of
silty sand to be classified as Category It,
but the permeability of this silty sand
may be inadequate to allow the LCS to
function properly. The base of the unit
may need to be modified.
" Facilities sited in Category III and IV
locations have overburden materials
that do not have T-values that are at
least equal to the active life of the unit
or 20 years, whichever is greater. These
units should install earthen or synthetic
liners or modify the existing subbase
such that, in combination with the
overburden, the composite T value
meets the standard. This may require
measures such as soil amendments,
recompaction of existing materials, and
installation of synthetic membranes.
As discussed earlier, under this
approach a final cover system that
prevents liquid filtration into the water
after closure is necessary. Acceptable
methods for determining the design for
such a final cover were discussed in a
previous section.
(3) Empirical Methodology. A third
approach for determining the landfill
design characteristics necessary to
comply with this rule's design goal relies
on the use of ground-water monitoring
data from existing MSWLFs, Under this
approach, an owner or operator
planning lateral expansions of an
existing facility or planning to build new
units in similar locations to an existing
unit could use ground-water monitoring
results from existing units to determine
if the new or expanded units need to
employ designs that are more protective
than the existing unit. If the
concentration of constitutents detected
in the existing units' ground-water
monitoring wells do not exceed the
design goal (and leachate from the unit
could be reasonably expected to have
reached the monitoring wells), then the
new or expanded unit would not have to
apply a more elaborate containment,
design than the existing unit has to
comply with this rule's design goal.
Four conditions would have to be met
before this approach could be used.
, First, the new or expanded unit must
have sufficiently similar location and
waste characteristics to the existing unit
to not pose greater threats to human
health and the environment than the
existing unit. Second, the existing unit
must have operated ground-water
monitoring wells.over a long enough
period to allow for leachate generation
and release (accounting for the time
required for failure of any liners) and
migration through the unsaturated and
saturated zones to the monitoring wells.
Third, the ground-water monitoring data
must address the Phase I parameters
(and Phase II parameters, if Phase II has
been triggered). Fourth, the monitoring
data must be supplemented with
appropriate modeling to predict the fate
of hazardous constituents over a time
period equivalent to the post-closure
care period proposed today. This
:approach would be used most frequently
for expansions of existing MSWLFs that
have conducted ground-water .
monitoring over a long period of time.
The Agency recognizes that all three
approaches are new methodologies that
have not been a part of permitting
programs. Comment is requested on the
appropriateness of these approaches to
a specific permit program or an
individual landfill design. Comment is'.
requested on the overall approaches and
on ways to modify any approach to
make it easier to incorporate into an
existing permitting program.
E. Subpart E—Ground-Water
Monitoring and Corrective Action
EPA today is proposing ground-water
monitoring and corrective action
requirements to ensure that ground-
water contamination at new and
existing MSWLFs will be detected and
cleaned up as necessary to protect
'human health and the environment.
These requirements reflect : ;
Congressional intent, as interpreted
through HSWA and the accompanying
legislative history, that protection of
ground water be a prime concern of the
re.vised Criteria. HSWA specifically
directed EPA to require ground-water
monitoring as necessary to detect
contamination and corrective action, as
appropriate, to protect human health
and the environment.
The existing Criteria under § 257,3-4
require that a facility or practice shall
not contaminate an underground
drinking water source beyond the solid
waste boundary or beyond an alternate
boundary established by the State. The
existing Criteria define "contaminate" to
mean the introduction of a substance
that would cause: (1) An MCL for any of
10 inorganic chemicals, four chlorinated
hydrocarbons, or two chlorophenoxys to
be exceeded or (2) a background level to
be exceeded for any of these 16
constituents when such background
concentration already exceeds an MCL.
The existing Part 257 does not
specifically require facilities to monitor
ground water beneath their units or to
implement a corrective action program
when ground-water contamination has
occurred. Facilities that are in violation
of the current Criteria, however, are
required to close or enter into a
compliance schedule with their
respective State.
Today's proposed Criteria revisions
completely replace the existing criteria
for MSWLFs under 40 CFR 257.3-4,
providing ground-water monitoring and
corrective action requirements under 40
CFR Part 258 for all new and existing
MSWLF units. The proposed
requirements call for assessment of the
hydrogeology beneath landfill units,
ground-water monitoring, reports on
ground-water quality, the establishment
of ground-water trigger levels and
ground-water protection standards, and
corrective action. These requirements
are discussed separately below.
The corrective action program
propOiSed today addresses releases to
ground-water only. In section 4010 of
HSWA, Congress specifically instructs
the Agency to evaluate the current
Subtitle D criteria (40 CFR Part 257) for
their aidequacy to protect human health
and the environment from ground-water
contamination. Congress clearly
considers ground-water contamination
to'be ihe major concern, and indeed,
requires the new criteria (today's
proposal) to provide for ground-water
monitoring to detect contamination and
corrective action, as appropriate. For
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33368
Federal Register / Vol. 53, No. 188, Tuesday, August
this reason, tho corrective action
program envisioned today addresses
releases to ground water. In addition,
there are other authorities the Agency
may use to address corrective action at
MSWLFs. These authorities (e.g.,
CERCLA, RCRA Section 7003, the Clean
Water Act) may be used to address
media other than ground water.
Tho Agency did, however, consider
addressing corrective action for all
media while dtjveloping today's
proposal. The Agency requests comment
on flie need for corrective action
requirements for surface water and soil
contamination at MSWLFs. (The Agency
currently is assessing the risks
associated with releases to air from
MSWLFs and ia considering proposing
regulations to control these emissions.)
CurrenUy, the .Agency has very little
data describing the extent or the risks
posed by soil or surface water
contamination at MSWLFs.
If corrective action requirements were
deemed necessary for surface water and
soils, the Agency would most likely
consider provisions similar to those
required for ground water. Specifically,
the Agency would consider requiring
monitoring, trigger levels, a corrective
measures study, cleanup standards, and
criteria for selecting remedies.
Appropriate trigger levels for surface
water may be water quality standards
(WQS) (developed by the State based
on Federal Water Quality Criteria) or, if
a WQS was unavailable, MCLs may be
appropriate (for surface waters used for
drinking water). If neither MCLs nor
WQS has been established, an
appropriate trigger level may be a
concentration that meets the criteria
specified in § 258.52 of today's proposal,
assuming consumption of the
contaminated water. If the surface
waters are designated for a use other
than drinking water, the appropriate
trigger level may be a concentration
established by the State that meets the
criteria specified in § 258.52 of today's
proposal and takes into consideration
the use or uses of the receiving waters.
Appropriate trigger levels for
contaminants in soils might be
concentrations that meet the criteria
specified in § 258.52 of today's proposal
and that assume exposure through
consumption of the contaminated soil.
If trigger levels for soils and/or
surface water cannot be developed
(because a concentration that meets the
criteria in § 258.52 is not available), an
appropriate trigger level might be a
State-developed concentration that
serves as an indicator for protection of
human health and the environment and
incorporates the above-referenced
exposure assumptions. If not health-
based trigger level is available, the
appropriate trigger may be the
background concentration.
If the Agency expands the critiera to
address corrective action for releases to
all media, it may consider using the
following compliance points. For soils,
the point of compliance for achieving the
cleanup level may be any point where
direct contact exposure to the soils may
occur. The State may specify the
locations or methods for detennining
appropriate locations where soil
samples should be taken to demonstrate
compliance with the soil cleanup
staadard(s). For surface water, the
criteria might require that the surface
water cleanup standard be achieved at
the point where the release(s) enters the
surface water in its highest
concentration. The State may specify .
the location where surface water or
sediment samples should be taken to
monitor surface water quality and to
demonstrate that compliance with the
surface water cleanup standard has
been achieved.
1. Section 258.50 Applicability
Today's proposed ground-water
monitoring and corrective action
requirements apply to the owners or
operators of all new and existing
MSWLFs. The Agency has several
reasons for applying ground-water
monitoring requirements to all new and
existing MSWLFs. First, the Agency
believes that the Congressional intent
was to require ground-water monitoring
at all MSWLFs that may receive HHW
or SQG waste. Section 4010(c) directs
EPA specifically to include ground-
water monitoring "as necessary to
detect contamination" among the
revisions to the criteria and, while
allowing the Agency to consider
practicable capability, does not identify
any exceptions to this requirement. The
legislative history also is silent with
respect to any exemptions from ground-
water monitoring.
Second, as discussed earlier in this
preamble, EPA has evidence that gound
water has been contaminated by
MSWLFs on a local basis in many parts
of the nation and on a regional basis in
some heavily populated'and
industrialized areas. Evaluation of 163
MSWLF case studies has indicated
ground-water contamination or adverse
trends in ground-water quality at 146 of
these landfills. The Agency recognizes
that these case studies may not be
representative of the universe of
MSWLFs; however, they do provide
examples of the impacts of improperly
designed or operated MSWLFs.
Current data from a 1986 survey
indicate that only 25 to 30 percent of
MSWLFs currently are equipped with
ground-water monitoring systems;
therefore, the total number of MSWLFs
that are contaminating gorund water is
unknown. Information submitted by the
States in 1984, however, indicated that
ground-water contamination has been
detected at 586 active MSWLFs or
roughly 25 percent of those facilities that
currently are monitoring ground water.
The nature and extent of the
contamination from these sites is
unknown. In addition, as of May 1986,
EPA has included 184 MSWLFs on the
Superfund National Priorities List.
The case studies and risk assessments
indicate that these failing landfills are ,
located in a wide range of hydrogeologic
and climatic settings, making it virtually
impossible, on a regional basis, for the
Agency to predict which existing
landfills may be contaminating ground-
water resources. Therefore, the ground-
water monitoring requirements are not
restricted to landfills of a particular age
or region.
Third, ground-water monitoring is the
most reliable method for detennining
whether a landfill is in compliance with
the overall performance standard of the
proposed Criteria revisions, i.e., to meet
health-based limits for hazardous
constituents in the ground water at the
waste management boundary or
alternative boundary specified by the
State. Even the best designs, operating
practices, and quality control
procedures cannot always prevent
unexpected failure of a landfill.
Therefore, ground-water monitoring at
all facilities, including those that are
properly designed and operated, is
viewed by the Agency as an essential
measure to ensure protection of human
health and the environment.
Because this proposal requires
MSWLFs to conduct ground-water
monitoring, today's action effectively
prohibits the location of MSWLFs in
areas where subsurface conditions
prevent monitoring of contaminant
migration from the landfill unit
MSWLFs in such unmonitorable areas
will be unable to receive an operating
permit from the State. Some geologic
settings that could preclude effective
ground-water monitoring are fractured
bedrock where complex fractures and
joint systems impede flow direction
prediction, and areas where extensive
subsurface mining or faulting has
modified flow direction. The ability to
perform corrective action as necessary
also must be considered. It is the
responsibility of the owner or operator
to prove that a landfill unit can be
monitored. The Agency requests
comment on adding a specific locatior
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Federal Register / Vol. 53, No. 168, Tuesday. August 30, 1988 / Proposed Rules
33367
restriction for unmonitorable areas in
the final rule.
Section 258,50(b) specifies that
ground-water monitoring requirements
of § 258.50 through § 258.55 will be
, suspended for owners and operators
who can demonstrate that there is no
potential for migration of hazardous
constituents from the landfill unit to the
uppermost aquifer during the active life,
closure, or post-closure periods. The
requirements of § 258.56 through
§ 258.58 are never suspended, however.
The proposed limited suspension of the
ground-water monitoring requirements
provided hi the | 258.50(b) is designed
for MSWLF units located in
hydrogeologic settings that prevent
leachate migration to ground water for
very long periods of time. In such a
setting, leachate from the MSWLF
should not be able to reach the
uppermost aquifer during the active life,
closure, or during post-closure care.
Because of the very favorable
hydrogeologic conditions, such settings
are highly desirable for the location of
MSWLFs and the Agency wishes to
encourage the use of these settings.
Furthermore, requiring ground-water
monitoring in these settings would place
an additional financial burden on the
owner or operator with very little added
protection to human health and the
environment. The financial burdens
placed on owners or operators in these
settings would be high because of
increased drilling costs caused by the
extreme depths to ground water that are
typical in these settings.
The Agency intends to ensure that
there is a high degree of confidence in
the demonstration that no leachate will
reach the uppermost aquifer before an .
exemption from the ground-water
monitoring requirements is allowed.
Therefore, today's proposal requires that
the demonstration be conducted by a .
qualified ge'dlogist or geotechnical
engineer based on site-specific
hydrogeologic information or, where •
that is insufficient, based on
assumptions that maximize the rate of
hazardous constituent migration.
While § 258.50(a) of today's proposal
requires ground-water monitoring at all
MSWLFs, except in the rare
circumstances described above, the
Agency is proposing to ease the burden
of this requirement by phasing in the
ground-water monitoring requirements
over time. The Agency is proposing this
approach because the thousands of
wells that will be needed at the
approximately 6,000 existing MSWLFs
are expected to cause shortfalls in the
availability of competent •
hydrogeologists and drilling companies
who' must assist the owner or operator
in sampling and analyzing the landfill's
hydrogeology, provide recommendations
on well-placement, drill the appropriate
bore holes and monitoring well holes,
and install the monitoring wells.
Furthermore, the Agency recognizes ,
that die proper review and evaluation of
proposed ground-water monitoring
programs will place significant demands
on State resources. Therefore,
§ 258.50(c) of today's proposal requires
Sta tes to establish compliance
schedules for each facility within six
months of the effective date of this rule.
This six-month period is the maximum
amount of time that a State should take
in setting compliance schedules. The
sooner an owner or operator knows
when the MSWLF must be in
compliance with the ground-water
monitoring requirements, the better the
necessary activities can be planned. The
Agency has set goals for the percentage
of existing units that must be in
compliance after the effective date of
tkis rule. Within two years of the
effective date, 25 percent of the existing
landfill units must be in compliance;
within three years of the effective date,
50 percent of the existing landfill units
must be hi compliance; within four years
of the.effective date, 75 percent of the
existing units must be in compliance;
and all landfill units must be in
compliance, within five years of the
effective date. Any new unit must be hi
compliance with the ground-water
monitoring requirements before
accepting waste.
States should set compliance ,
schedules for each facility based on an
evaluation of the potential risks posed
by the facility. Risks posed to human
health and the environment can be
weighed by considering the proximity of
human and environmental receptors,
design of the landfill unit; age of the
landfill unit, and resource value of the
underlying aquifer. The Agency believes
that ground-water monitoring is critical
at existing facilities that pose a threat to
human health or the environment and
expects States to move aggressively to
address these facilities as soon as
possible.
If a State does not set a schedule of
compliance for MSWLF units, :
§ 258.5iO(dj specifies a compliance
schedule for owners or operators of
landfills. This ."fall-back" schedule is
based on distance to the nearest
drinking water intake. While this
• method of setting priorities does not
ascertiiin potential risk as well as the
method outiined hi § 258.50(c), it is
objective and easy for an owner or
operator to determine.
2. Sections 258.51-55 Overview of
Ground-Water Monitoring Requirements
Today's proposed Criteria revisions
require a system of monitoring wells to
be installed at new and existing
MSWIFs. The, proposed Criteria
revisions also provide procedures for
sampling these wells and methods for
statistical analysis of analytical data
derived from the well samples to detect
the presence of hazardous constituents
released from MSWLFs. The Agency is
proposing a two-phased ground-water
monitoring program and a corrective
action program. This phased approach
to ground-water monitoring allows
proper consideration of the transport
characteristics of MSWLF leachates hi
ground, water, while protecting human
health and the environment. As shown
in Figure 3, the proposed monitoring and
corrective action programs provide for a-"
graduated response over time to the
problem of ground-water contamination
as the evidence of such contamination
increases, thereby keeping down costs.
BILLING CODE 6560-SO-M
-------
FIGURE 3
CO
CO
CO
SUBTITLE D GROUND-WATER MONITORING AND CORRECTIVE ACTION
ESTABLISH PROGRAM
State:
Approves ground-water
monitoring system and
sampling and analysis
program
Establishes trigger level
(MCL where available '
orriskteveiinlO^to
10 "7 range) that
triggers assessment
hi*
PHASE I MONITORING
Monitor * for indicators:
• metals
• VOCs
• Ground Water
chemistry
If a statistically
significant change
occurs, go to Phase II
PHASE II MONITORING
Monitor 'for hazardous
constituents
If any constituent
exceeds trigger level,
assessment begins
ASSESSMENT AND REMEDY
SELECTION
Owner or operator:
• Assess corrective measures
State:
• Evaluates corrective
measure
• Selects remedy
• Establishes dean-up
standard (i.a.,GWPS)
• considering site-specific
factors
• Sets schedule
CORRECTIVE ACTION
Owner or operator
implements remedy
selected by State, carries
out until GWPS is met
' Minimum monitoring frequencies: Semiannual during Phase I and quarterly during Phase II for constituents found above background.
-------
I"esday' August 30, 1988 / Proposed Rules
33369
The proposal requires that all new
and existing MSWLFs begin their
ground-water monitoring programs by
complying with the Phase I monitoring
requirements. When a change in ground-
water chemistry is indicated by an
increase or decrease of two in more of
parameters (1) to (15), or when any one
of parameters (16) to (24) or the volatile
organics (VOCs) listed hi Appendix I is
detected at statistically significant
levels above background, Phase IE
monitoring is triggered. Phase H requires
monitoring an expanded list of
hazardous constituents (see Appendix
II). If any of the Phase II parameters are
detected at statistically significant
levels above background, the owner or
operator must compare those levels to
the appropriate ground-water trigger
levels. The State will set the ground-
water trigger levels as specified in
§ 258.52. These "trigger levels" trigger
the assessment of corrective measures
and establishment of the ground-water
protection standard. Corrective action
continues until the owner or operator
demonstrates compliance with the
GWPS for a period of time determined
by the State to be appropriate, based on
site-specific factors. The Agency is
considering changing its Subtitle C
requirements from a three-year period to
One that is site-specific. EPA requests
comment on the appropriateness of a
minimum period of compliance for
Subtitle D.
The Agency is proposing that ground-
water monitoring, once initiated,
continue through post-closure care.
Adequate post-closure care is essential
for continued protection of human
health and the environment, and ground-
water monitoring is necessary hi
determining the effectiveness of post-
closure care. The Agency has not set
minimum monitoring frequencies during
the post-closure period, instead leaving
that determination entirely up to the
State. This decision was based on the
idea that the appropriate frequency at
which to monitor during post closure
will vary significantly not only among
units, but also overtime. Site-specific
information should be evaluated by the
State when determining post-closure
monitoring frequency. Factors that
should be considered by the State
include the hydrogeology of the site, the
age and design of the landfill, and the
operating history of the landfill. During
the early years of post-closure care (e.g.,
10 years), it may be appropriate to
monitor as frequently as during the
operating period. In many cases it may
be appropriate to lessen the frequency
of monitoring hi the latter years of post-
closure care. If during post closure a unit
triggers the next phase of ground-water
monitoring, it would be appropriate for
the State to set a monitoring frequency
the same as the minimum frequency
designated for the operating period.
Comments are requested on whether
individual monitoring wells at a landfill
unit should be allowed to be hi different
phases of monitoring. The Agency is not
proposing this option today, but believes
that this option could be appropriate in
situations where the unit is very large,
and only a few monitoring wells have
triggered the next phase of monitoring.
Once corrective action had been
triggered in one well, however, all of the
ground-water surrounding the particular
unit would be subject to corrective
action provisions.
o. § 258.51 Ground-Water Monitoring
Systems. Section 258.51 of the proposed
Criteria specifies requirements.
pertaining to appropriate methods for
constructing and placing ground-water
monitoring wells. The purpose of these
requirements is to ensure that
consistent, reliable ground-water
monitoring systems are installed at all
MSWLFs. The Agency has specified the
use of well systems because other
technologies may not be as reliable as
well systems for detecting changes in
ground-water quality, hi making this
determination, the Agency reviewed
many other methods of ground-water
monitoring, including resistivity, ground
penetrating radar, and lysimeters.
Detailed discussions of the strengths
and weaknesses of these methods for
use hi monitoring ground water at
MSWLFs are provided hi the
background document for Subpart E of
today's proposal.
The monitoring well system must be
designed so as to monitor the
performance of the landfill design in
terms of its ability to meet the design
goal (as defined in § 258.40(bJ) hi the
aquifer at the waste management unit
boundary or the alternative boundary as
specified by the State pursuant to
§ 258.40. As such, well location is linked
directly to the performance standard for
the design of the landfill unit. If the unit
is designed to meet the design goal at
the waste management unit boundary,
wells should be installed at the waste
management unit boundary. On the
other hand, if the unit is designed to
meet the design goal at an alternative
boundary, the wells should be installed
at the alternative boundary.
Section 258.51 allows the placement of
wells at the closest practical distance
from the waste management unit or
alternative boundary to account for the
presence of important structures, such
as run-off controls, anchors for liners,
and gas lines, that would be impaired or
destroyed by well installations in the
area,; Other factors can affect the exact
placement of monitoring wells. In some
hydrogeologic settings, perched water
tables and/or other hydrogeologic
phenomena may cause leachate from an
MSWLF to travel horizontally for a
significant distance before reaching the
uppermost aquifer. Therefore,
§ 258.51(a) specifies that the State may
select the closest practical distance
downgradient from the waste
management unit boundary or the
alternative boundary (as specified by
the State) if the State determines, based
on site-specific hydrogeologic
evaluations required in § 258.51, that the
uppermost aquifer would not be affected
directiy beneath the appropriate
boundary by release of leachate from
the MSWLF. •
In siome cases, several discrete units
may constitute the MSWLF. Because of
topographic conditions and design
limitations, constructing discrete cells
may be the only means of constructing a
landfill on the property. Section
258.51.(c) states that separate monitoring
systems are not required for each
landfill unit at a multi-unit facility if the
State approves the grouping of units.
Such approval would be alloxved only if
the multi-unit ground-water monitoring
system will be protective of human
health and the environment. If local
conditions make it infeasible or
impractical to install a monitoring
system around each landfill unit, the
State may allow the grouping of units
within one monitoring system. Factors
that the State should consider when
deciding whether more than one unit
should be within a monitoring system
include: the number of units, the spacing
of the units, the orientation of the units
to one another, the age of the units* and
the hydrogeologic setting. The State
should^ not approve the grouping of units
within one monitoring system if the
downgradient portion of the system
would be located more than 150 meters
from any landfill unit.
The Agency does not believe that
there a.re any differences between
MSWIFs and hazardous waste land
disposal units with respect to the factors
used to determine appropriate types of
well materials or well construction
techniques. Therefore, today's proposed
performance standards for ground-water
monitoring system design found in
§ 258.51(d) are similar to those specified
for hazardous waste disposal facilities
in 40 CFR Part 264. This similarity
ensures consistent design and
construction standards for monitoring
wells at all RCRA landfill facilities.
-------
Because hydrogeologic conditions
vary widely from one site to another, it
is not possible to establish requirements
specifying the exact number, location,
and depth of monitoring wells needed to
adequately monitor ground water in the
aquifer. Such requirements are
dependent on actual site-specific aquifer
and geologic conditions. Therefore, in
§ 258.51(e) the Agency has proposed
that specifics of the system be based on
aquifer thickness, flow rate, and flow
direeHon, and the characteristics of the
material overlying the aquifer. For
example, a complex aquifer flow syster-
may require multilevel wells to
effectively monitor ground water. A
facility located in an area of very low
hydraulic gradient may be better
monitored by a ring of wells, since
mounding could cause contaminant flow
in all directions.
b. Section 258.52 Determination of
Ground-Water Trigger Level. This
section discusses what procedures the
State must follow when establishing
appropriate trigger levels. Trigger levels
must be established by the State before
the Phase I monitoring program is
initiated. The levels established are
health- and environmental-based levels
that are determined by the State to be
indicators for protection of human
health and the environment. Where
appropriate, these levels are based on
promulgated standards; otherwise, they
are established by the State on the basis
of general criteria described below.
Contamination exceeding trigger
levels indicates a potential threat to
human health or the environment that
may require further study. Therefore, the
owner or operator must conduct an
assessment of corrective measures
whenever concentrations of hazardous
constituents in the ground water exceed
trigger levels. Trigger levels provide the
owner or operator a point of reference
for suggesting and supporting alternative
remedies during the assessment of
corrective measures [see preamble
discussion for § 258.58). Trigger levels
must be distinguished from ground-
water protection standards, which are
established during the remedy selection
process.
Under § 258.52 of today's proposal,
the concentration limits for the trigger
levels are: (1) Maximum contaminant
levels promulgated under § 1412 of the
Safe Drinking Water Act, or (2) if an
MCL has not been established, the
concentration limit is a health-based
limit established by the State that meets
the proposed criteria described in
§ 258.52(b){2) (i-iv), or (3) if levels under
(1) or (2) are not available, the
concentration limit is a level established
by the State that is an indicator for
protection of human health and the
environment, or (4) background levels, if
such levels are higher than _ .
concentrations under (1), (2), or (3), or if
concentrations under (1), (2), or (3) have
not been established.
The MCLs are maximum
concentrations of contaminants allowed
in water used for drinking. They are
based upon toxicity, treatment
technologies, and other feasibility '
factors such as availability of analytical
methods. The MCLs are set following an
analysis based on health considerations
as guided by the SDWA.
The use of MCLs is consistent with
current ground-water protection
standards under 40 CFR Part 264,,
Subpart F (Releases from hazardous
waste disposal facilities). Under the
1986 Amendments to the SDWA, MCLs
must be set for 83 specific contaminants
by 1989 as well as for any other
contaminants in drinking water that
may have any adverse effect upon
people's health and that are known or
anticipated to occur in public water
systems. Currently, there are 28 MCLs
promulgated; relevant MCLs to these
requirements are listed below in Table
2.
TABLE 2—MAXIMUM CONTAMINANT
LEVELS
CAS No.
71-43-2
56-23-5
1333-82-0
108-46-7
107-06-2
75-35-4
72-20-8 .-...
58-89-9
72-43-5....
7782-49-2....
93-72-1
71-55-6
79-01-6.
75-01-4
Chemical name
Benzene
Carbon tetrachloride
Chromium (VI)
para-Diohlorobenzane
1,2-Dicnloroethane
1 ,2-Dlohloroethylene
Endrin
Undane ~ -.
Methoxychlor
Selenium.......
Silvex (2.4.5-TP)
1 ,1 ,1 -Trichloroelhane
Trichloroethylene
Vinyl chloride
MCL
(mg/L)
0.05
1.0
.005
.01
.005
.05
.05
.075
.005
.007
.0002
.05
.004
.OQ2
.1
.01
.05
.01
.005
.2
.005
.002
The Agency is proposing that health-
based concentrations established by the
State be used for the trigger level when
MCLs are not available. These health-
based levels must meet four criteria
listed under § 258.52(b)(2) [i-iv). First,
they must be consistent with principles
and procedures set forth in Agency
guidelines for assessing the health risks
of environmental pollutants, which were
promulgated on September 24,1986 (51
FR 33992, 34006, 34014, 34028).
Second, the levels rnsut be based on
scientifically valid studies conducted in
accordance with the Toxic Substances
Control Act Good Laboratory Practice
Standards (40 CFR Part 792) or other
equivalent standards. 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. In addition, the
Agency guidelines for assessing the
health risks of environmental pollutants
(cited above) cite several publications
that outline procedures for evaluating
studies for scientific adequacy and
statistical soundness. Third, for
carcinogens, these levels must be
associated with a risk level within the
protective risk range. (See discussion in
Section DC.D.l.a. of today's preamble
concerning the design goal and EPA's
request for comment on alternative risk
ranges.) Finally, for toxic chemicals that
cause effects other than cancer or
mutations, the levels must be equal to a
concentration to which the human „
population (including sensitive
subgroups) could be exposed on a daily
basis without appreciable risk of
deleterious effects during a lifetime.
These criteria will ensure that the trigger
level represents valid and reasonable
estimates of levels in ground water that
are safe for human consumption.
Health-based levels that have
undergone extensive Agency scientific
review, but that have not been formally
promulgated, are available for many
chemicals. The four criteria proposed in
§ 258.52 and discussed above will-
enable the State to use these
.nonpromulgated levels to derive trigger
levels. Appendix HI provided health-
based levels that the Agency believes
meet these four criteria for selected
hazardous constituents. These levels
may be used to determine trigger levels.
EPA established these levels by an
assessment process that evaluated the
quality and weight-of-evidence of
supporting toxicological,
epidemiological, and clinical studies.
These levels are discussed below.
For noncarcinogens, health-based
limits based on Reference Doses (RfDs)
have been developed by the Agency's
Risk Assessment forum. An RfD is an
estimate of the daily exposure a
sensitive individual can experience
without appreciable risk of health
effects during a lifetime. The
experimental method for estimating the
RfD is to measure the highest test dose
for a substance that causes no
-------
33371
statistically or biologically significant
effect in an animal bioassay test. The
RfD is derived by dividing the "no
observed adverse effect level" (NOAEL)
by a suitable scaling or uncertainty
factor. Confidence in the RfD is
dependent on a number of factors,
including the quality and duration of the
animal study. The derivation of RfDs
has been evaluated and verified by
internal Agency review. Applying the
standard drinking water exposure
assumptions (i.e., a 70 kg person drinks
two liters of water a day for 70 years) to
RfDs yields the ground-water
concentration limit. Appendix III lists •
the RfDs (mg/kg-day) for several
hazardous constituents.
The use of the RfD is appropriate only
for noncarcinogenic constituents. EPA
science policy suggests that no threshold
dose exists for carcinogens; in other
words, no matter how small the dose,
some risk remains. The dose-response
assessment for carcinogens usually
entails an extrapolation from an
experimentalhigh-dose range where
carcinogenic effects in an animal
bioassay have been observed, to a dose
range where there are no observed
experimental data by means of a
preselected dose response model. The
carcinogenic slope factors (CSFs),
estimated by EPA's Carcinogen
Assessment Group, may be used to
calculate a dose that corresponds to a
given risk level by dividing the risk level
(e.g., 1 x 10-=) by the CSF. CSFs for
selected carcinogens are provided in
Appendix IE. This dose is called a risk-
specific dose (RSD). An RSD is an
estimate of the daily dose of a
carcinogen that, over a lifetime, will
result in an incidence of cancer equal to
a given risk level.
The ground-water concentration, in
milligrams per liter, can be calculated by
multiplying the RSD by the average
adult body weight (70 kg) over the
average water intake (two liters of
water per day). Chemicals that cause
cancer also may evoke other toxic ;
effects. These constituents may have
both an RfD and RSD available. In these
cases, the lower level (i.e., more
protective) should be used as the trigger
level.
EPA has developed a classification
scheme for carcinogens based on the
weight of evidence for carcinogenicity.
This scheme is presented in the
Agency's cancer guidelines (51FR 3992).
Appendix III includes the class for each
carcinogen listed. Known or probable
human carcinogens are designated as
Class A and Class B carcinogens,
respectively, under the Agency
guidelines. .Constituents for which the
weight of evidence of carcinogenicity is
weaker are known as Class C, or
possible human carcinogens under the
Agency's guidelines.
Examples are included in Appendix m
to illustrate how the States may use
RfDs and CSFs to set trigger levels. For
carcinogens, the State may use the CSF
to determine a trigger level anywhere
within the protective risk range. (See
discussion in Section K.D.l.a. of today's
preamble concerning the design goal
and EPA's request for comment on
alternative risk ranges.)
The Agency believes that the
protective risk range is appropriate for
setting a trigger level for carcinogens
without a MCL. For new MSWLFs, the
State should consider using the same
risk level for trigger levels as was used
for the design goal. For example, if the
MSWLF was designed to meet a 1 x ID'5
risk level at the chosen boundary, then"
the MSWLF should be triggered into an
assessment of corrective measures once
that risk level (for carcinogens with no
MCL) is exceeded. For existing
MSWLFs, to ease implementation, the
Agency suggests that the State choose
one risk level to be used at an MSWLF .
for all carcinogens that do not have an
MCL. The State may consider choosing
a risk level to use at all MSWLFs within -
the State. As discussed in the preamble
discussion for the design goal, the
Agency is requesting comment on two
alternatives to the protective risk range.
Any change made to the proposed
design goal criteria would most likely be
made for the trigger level. For example,
if a fixed risk level of 1 x 10~5 was
required as a design goal, then the
trigger levels for carcinogens without
MCLs would also be required to be set
atlxlO-".
RfDs and RSDs will be available soon
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. The risk assessment
information (i.e., RfDs and RSDs)
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 continues to review and verify
risk assessment values, additional
chemicals and data components will be
added to IRIS. A hard copy of IRIS soon
will be available through die National
Technical Information Service. The
background document for Subpart E
contains further information on IRIS.
If NlCLs or other health-based levels
meeting the proposed criteria are not
available or cannot be developed for use
as trigger levels, § 258.52(b)(3) allows
the State to establish a trigger level that
acts a:s an indicator for protection of
human health and the environment. In
many cases, partial data or data on
structural analogs will allow the State 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 an assessment of
corrective measures in any case), and it
will be clear that the constituent for -
which no level is available 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 a trigger level for that
constituent.
Finally, background concentrations
may be used as the trigger level when no
health-based level or indicator is
available or when background is higher
than ainy health-based level.
c. Section 258.53 Ground-Water
Sampling and Analysis. Section 258.53
of today's proposed Criteria revisions
includ.es requirements for consistent
sampling and analysis procedures that
are designed to ensure accurate ground-
water .monitoring results. Also included
in this section are requirements for
determining ground-water flow rate and
direction, establishing background
ground-water quality and applying
appropriate statistical analyses to detect
any changes in ground-water quality
beneath an MSWLF.
Section 258.53(a) requires that the
sampling and analysis techniques used
by owners and operators of MSWLFs be
sufficient to provide an accurate
representation of ground-water quality
in the uppermost aquifer beneath the
landfill. At a minimum, these procedures
must a.ddress sample collection,
preservation, shipment, chain-of-
custody, and quality assurance and
quality control (QA/QC). The Agency
recommends Chapter 2 of the "RCRA
Technical Enforcement Guidance
Dpcument" (TEGD) for use hi complying
with tliis section. Although this chapter
of the TEGD contains a number of
references to the hazardous waste
requirements under 40 CFR Part 264, the
recommended sampling and analytical..
procedures are appropriate for any solid
waste disposal facilities, including
MSWIFs. These recommendations
provide clear descriptions of how to
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33372
Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
conduct ground-water sampling and
analysis and also allow the use of
alternate procedures on a site-specific
basis. Therefore, by recommending the
TEGD, the Agency is not ignoring the
use of alternate procedures that are
consistent with the level of performance
reflected in the TEGD.
In the RCRA Subtitle G program, the
Agency has observed problems with
ground-water sampling procedures,
monitoring well network design,
laboratory analyses, and data
interpretation. EPA believes that a
rigorously enforced, comprehensive
quality assurance program based on
sound quality objectives and backed up
with an appropriate set of reference
methods and procedural guidance will
assist in remedying these problems. As
a result, the Agency is considering
adding QA/QC requirements to the
sampling and analytical methods for
Subtitle C facilities under § 264.97(e). To
avoid duplicating the problems of
Subtitle C, § 258.53(a)(5) of today's
proposal requites that QA/QC
procedures be included in sampling and
analysis techniques. Owners or
operators should refer |o^EPA guidance
on 'Test Methods for Evaluating Solid
Waste (Physical/Chemical Methods)"
for information on QA/QC procedures
(Ref. 34).
Section 258.53{d) of today's proposal
requires that ground-water elevations be
measured immediately prior to
sampling. In addition, the owner or
operator must determine the rate and
direction of ground-water flow in the
uppermost aquifer each time ground-
water gradient changes. These
requirements for determining ground-
water flow rate and direction are
Included to ensure that any unexpected
changes in these parameters will be
recognized and that changes in the
location or spacing of monitoring wells
will be made us needed to maintain the
Integrity of ground-water monitoring
systems. Ground-water flow rates and
directions may vary seasonally or over a
number of years due to human-made or
natural causes and, because the spacing
and location of wells are highly
dependent on these parameters, the
Agency has decided not to rely entirely
on the measurements of these
parameters made prior to well
installation. In selecting a site-specific
frequency, i.e., tied to changes in
ground-water gradient, the Agency has
attempted to strike a balance between
areas where aquifers exhibit no
variability and those that exhibit
frequent changes hi flow rate and
direction. At facilities that overlie
aquifers with little or no variability in
gradient, these assessments may be
fairly infrequent. At facilities overlying
aquifers with more variable ground-
water gradients, more frequent
assessments of flow rate and direction
may be required, based on
measurements of piezometric surface
taken at least semiannually. Ground-
water flow rate and direction data
should be presented in the form of a
flow net.
Today's proposed ground-water
sampling and analysis procedures also ;
include requirements for establishing
background ground-water quality.
Information on background ground-
water quality is essential for
determining whether the presence of
monitoring parameters or constituents
beneath an MSWLF indicates leakage
from the landfill unit. Section 258.53[e)
requires the owner or operator to
establish background values for those
monitoring parameters or constituents
included in the monitoring phase
applicable to that MSWLF. For example,
if the MSWLF currently is in the Phase I
monitoring program, background values
must be established for all of the Phase I
parameters. Background values of all of
the Phase n parameters must be
established if Phase H monitoring is
triggered. The minimum number of
background samples needed to fulfill the
statistical requirements will depend on
the statistical procedures selected.
Background ground-water quality
must be established hi wells that are
hydraulically upgradient of the MSWLF,
except as allowed in §§ 258.53 (f) and
(g). Section 258.53[f) states that
background quality at landfill units may
be based on samples from wells that are
not upgradient from the landfill if
hydrogeologic conditions do not allow
the owner or operator to determine what
wells are upgradient, and sampling at
other wells will provide an indication of
background ground-water quality that is
as representative or more representative
than that provided by upgradient wells.
Areas with no hydraulic gradient and
those with reversing hydraulic gradient
(such as those influenced by tides) are
examples of hydrogeologic conditions
that could make it impossible to
determine which direction is upgradient.
Section 258.53(g) of today's proposal
gives the State flexibility in determining
background ground-water quality on a
site-specific basis where such levels
cannot be measured on the facility. An
example of such a situation would be a
landfill unit that is leaking and causing a
mounding effect (where leachate is
flowing out of the unit in all directions).
If the leachate flowed far enough from
the unit, it could contaminate all of the
ground water between the unit and the
property boundary, thus leaving no
uncontaminated ground water from
which to determine background ground-
water quality. The State would be able
to set background values for this site.
Background ground-water quality should
be based on actual monitoring data from
the aquifer of concern. A State may
have well data from another landfill site
that overlies the same aquifer, or the
data may be from another type of well
from which the State can obtain data.
The reader is referred to the background
document for Subpart E for a full
discussion of this provision.
The requirements for applying the
statistical procedures contained in
§258.53(h) are the same as the
procedures proposed on August 24,1987,
for hazardous waste disposal facilities
under Subtitle C of RCRA (see 52 FR
31948). The Agency believes that the
revised Subtitle C procedures are also
appropriate for MSWLFs and provide
sufficient flexibility to allow effective
State implementation at MSWLFs. The
final statistical procedures promulgated
under § 258.53(hj will reflect comments
received on this proposal as well as the
final statistical package promulgated
under Part 264.
The required statistical procedures for
comparing background ground-water
quality data to those samples taken at
downgradient wells are included hi
today's Criteria revisions to clarify the
purpose and timing of statistical
comparisons and their relation to
ground-water sampling events at
MSWLFs. These requirements ensure
that statistical comparisons of analytical
results between background and
downgradient monitoring wells will be
made promptly after each sampling
event, and will cover all applicable
parameters and constituents at
MSWLFs. For further discussion of the
statistical requirements, the reader is
referred to the preamble for the
proposed Subtitle C procedures found at
52 FR 31948.
d. Section 258.54 Phase I Monitoring
Requirements. The Phase I monitoring
parameters proposed today in § 258.54
were developed with the dual objectives
of providing a reliable means of
detecting the possible presence of
releases from MSWLFS while avoiding
unnecessary analytical costs to the
regulated community. The proposed list
of Phase I parameters is consistent with
the results of research conducted under
the direction of EPA's Office of
Research and Development and other
institutions. These research results •
reveal that Phase I parameters (1)-(15)
are reliable indicators of ground-water
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£ederai Register /Vol. 53. No. 168. Tuesday, August 30. 1988 / [Proposed Rules
33373
chemistry and possible precursors to
other more hazardous constitutents that
may be released later from MSWLFs.
Furthermore, States typically require
routine monitoring of one or more of.
these parameters (1) to (151 at MSWLFs
as the primary means of detecting
ground-water contamination. The major
cations and anions on the Phase I
parameter list are those used to classify
ground water into geochemical facies.
These parameters are, therefore, useful.
for tracking changes in the ground-water
geochemistry that may occur as the
result of leakage from an MSWLF. In
addition, the Agency is proposing to
require semiannual monitoring for the
metals (arsenic, barium, cadmium,
chromium, lead, mercury, selenium, and
silver), cyanide, and 46 VOCs.
The Agency believes that these VOCs
in Appendix I constitute the first group
of potentially hazardous constituents
that would be present in the ground
'. water prior to other, less mobile,
constituents proposed for Phasa II (see
Appendix n of the proposed rale.) Due
to their chemical nature, these VOCs
generally would not migrate any faster
than the non-VOC Phase I parameters,
but do migrate faster than most of the
Phase II constituents. Research by EPA
, and other institutions that supports
these statements is summarized in the
background document to this Subpart.
Heavy metals and cyanide also can
exist under certain conditions in a well-
defined leachate ground-water plume,
depending on the waste present in the
landfill. It is not certain whether heavy
metal concentration would-be as
significant in leachate plumes from
newer MSWLFs as they tend to be
attenuated more than other constituents
such as VOCs. MSWLF leachates
containing heavy metals can, however,
pose serious threats to human health
and to aquatic environments; therefore,
the Agency is proposing to include the
heavy metals that are included in the
primary drinking water standards along
with cyanide and the VOCs as the
minimum Phase I monitoring
parameters.
The reader is referred to the
background document for this Subpart
for more information.
The Agency is proposing to include
the following as the minimum Phase I
parameters that must be monitored for
at least semiannually:
(1) Ammonia (as N)
(2) Bicarbonate (HCO3)
(3) Calcium
(4) Chloride
(5) Iron
(8) Magnesium -..
(7) Manganese (dissolved)
(8) Nitrate (as N)
(9) Postassium -
(10) Sodium
(ll)Sulfate
(12) Chemical Oxygen Demand (COD)
(13) Total Dissolved Solids (TDS)
(14) Total Organic Carbon (TOC)
(15) pH
(16) Arsenic
(17) Barium
(18) Cadmium --.
(19) Chromium
(20} Cyanide •
(21) Lead .
(22) Mercury
(23) Selenium
(24) Silver
(25) Volatile Organic Compounds listed
in Appendix I
The Agency specifically requests
comment on the proposed set of Phase I
monitoring parameters and the
monitoring frequency. EPA is proposing
that the frequency of monitoring during
Phase I be determined by considering
aquifer flow rates in the vicinity of the
monitoring wells and the resource value
of the aquifer. Semiannual sampling is
proposed as a minimum frequency
during the active Me and closure of a
unit. This frequency also is the minimum
specified in/the.ground-water monitoring
requirements (40 CFR Part 264) for
hazardous waste landfills. The Agency
believes that a six-month maximum
interval between sampling events is
reasonable in terms of protection of
human health and the environment and
the burden on the regulated community. .
During post-closure care, a State may
set a different minimum monitoring
frequency. '
Today's proposal does not set a
minimum frequency for ground-water
monitoring during post-closure care.
Because of the variable length of the
post-closure care period and the
variability of site-specific conditions,
the Agency believes it is more
appropriate to allow States to determine
the frequency of ground-water
monitoring on a site-specific basis.
Section 258.54(d) states that a Phase I
ground-water monitoring program must
be expanded to Phase II ground-water
monitoring when two or more of the ,
parameters (1) to (15) are detected at
levels that significantly differ from
background levels. Because the
parameters (1) to (15) are monitored to
detect changes in ground-water
chemistry beneath an MSWLF, both
increases and decreases in these
parameters may be significant. The .
Agency is not implying that decreased
levels of any of these parameters
indicate degradation of ground water,
just that further monitoring should be
done to determine what is causing the
change in ground-water chemistry. For
example, a change in water chemistry,
such"as a decrease in pH and sulfate,
may indicate the release of liquids from
a landfilL The Agency is proposing to
use increases or decreases of any two or
more of the parameters (1) to (15) to
trigger Phase II monitoring because
preliminary analysis of ground-water
samples taken at MSWLFs show that:
(1) Substantiated leachate
contaimnation of ground water from
•MSWIJFs normally involves more than
one of those Phase I parameters and (2)
levels of a single one of those Phase I
parameters in backgroud ground-water
samples in some areas of the country
. are highly variable, which could lead to
false indications of contamination.
Section 258.55(a) states that if anyone of
parameters (16) to (24) or the VOCs
listed in Appendix I is detected at levels
that are statistically significant above
background, the unit must begin Phase II
monitqring. During Phase II monitoring,
the owner and operator has the .
opportunity to revert back to Phase I
monitoring if it is found that there has
not been a statistically significant
increase over background levels of
relevant parameters (see § 258.55(e)).
Once an MSWLF has triggered Phase
II monitoring, the owner or operator is
not required to monitor parameters (1)
to (15). States may require an owner or
operator who has entered a Phase II
monitoring program to continue
occasicmal monitoring for parameters (1)
to (15), particularly if that State has
established corrective action
requirements that involve those
parameters. The Agency does not intend
to requiire any corrective action for
Phase Iparameters (1) to (15) because:
(1) It is not apparent that these
parameters would ever occur at high
levels without corresponding increases
over background levels for many of the
constitutents listed in Appendix II of the
proposed regulations, (2) it is difficult to
assign a target level for cleanup of the
non-VOC, nonmetal Phase I
parameters, since none of them are
hazardous to human health at levels
found in MSWLF leachate, and (3)
cleanup of any Appendix II constituents
is likely to result in concurrent cleanup
of the o'ther Phase I parameters to
acceptable levels.
Section 358.54(d}(3) of today's
proposal allow the MSWLF owner or
operator to demonstrate that detection
.of significant changes in ground-water
quality during Phase I monitoring was
caused by sampling and analytical error "
or by a source other than the MSWLF;
The Ageincy included this provision in
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,83374
Federal Register / Vol. '53, .No. .168, Tuesday, August 30, 1988 /
today's ^proposal because .it is Jknown
thatsampling and analytical-errors .are
made with sufficient freguenqy.that they
cannot be ignored. This provision avoids
unnecessary costs to ihe owner or
operator who .would otherwiseibe
.regulred to begin Phase II monitoring.
Furthermore, this provisionJs.consistent
with:theRGRA:Subtitle,C:regulations
governing hazardous waste landfills.
Owners or operators of MSMffiFs
attempting to make Ibis demonstration
muat notify the State of their.intent,
submit.the demonstration to the State Jn
the form of :a.report, and .continue the
Phase I monitoringprqgram. If the
demonstration is not successful, :the
owner or operator must establish^
Phase n monitoring program within:a
reasonable time periodL
The Agency specifically requests
comments ontthe list of Phase:!
jnonltoringparameters,:methods:for
setting trjggeringmechanisms., .and
j>Qteritial:required:action8 si MSWLEs
that are contaminating ground water
only withjiGn-VOC,-nonmetal
parameters H) to:(l§) Phase*
conatituents. The Agency also jequests
information about any MSWtFs that are
known to be rausing significant
contamination of ground water with
only:non-VOG,:nonmetal;Phase I
constituents.
.ft Section £58.55 Phase H-Monitoring
Rcqulaunettls. If itJs determined that
the ground water .contains .significant
increases lor decreases) over
background.lev.els.of.Phase.I
parameters, .the Phase n monitoring
program isttrjggered. The purpose ;df this
phase ofjground-watermonitoring:is:to
determine =tlie concentration jof
hazardous nonstituents specifiediin
Appendix H of .today's ^proposal.
Therefore, JPhase EL monitoring is
initiated by sampling all wells .and
analyzing each sample for :all ;of ;the
constituents listed JiuAppendix-ILof
today's proposal.
Triggering intoShase ttdossaaot
necessarily indicate a,threat to human
health and the environment. Ra"ther,
entering Bhase:II monitoring ;signalsithe
need to more.'fully.analyzeiground water
to determiRe if 'anytjonstituent has
^ceeded healthTbased'levels (Le,,
trigger levels]. .The 'technical basis for
selection of the.Ajopendix.n"parameters
for Phase n monitoringiB'pnesented
below and;fa fee background documBnt
for;Sub,parl: E of .today's prqposal.The
Agoncy'B'major objective con:identifying
the constituents lor JPhase n monitoriqg
was .to include .thasc hazardous
constituents ithdtjjose risk io human
health'and.the iCnvirxuiment, are present
in 1 ISWLFdeachate. and may
potentially migrate to ground water.'The
proposed constituents (AppendixJIiof
today's proposal) are the same as .those
used for the GWPS at hazardous .waste
disposal facilitiesiunderSubtitle C of
RCRA.'.The Ajency conBidered;s:eyeral
options-for'flieiflpecific'listofiPhasell
constituents. The regulatory alternatives
included: (1) The list of constituents in
the current Subtitle D Criteria, (?) the
list of priority pollutants, (3) a-list,of all
constituents that have been.found;in
MSWLF leachates, (4) a site-specific list
of constituents, based on analyses of
leachate samples, and (5) theslistflf
constituents in Appendix n.
The first option the Agency
considered was the .10;inorganic
chemicals, four chlorinated
hydrocarbons,,anditwo.chlorophenoxys
specifiedon She current Criteria ,[40 ,CER
Part 257). .This joption was rejected
becausje.the Agency!s. analytical
leachate data mdicate.the presence of
numerous other .toxictorganic
compounds sthat iwould:not:be.addrese.d
Jgrihis.op.tion.
The second option ^considered was the
list o'fpriority .pollutants amder^section
ao^faJID.Df thetGWA. Tie-constituents
.on^tius list -are toxkvand many have
"iieen;found:in;leachate:8aniples.frpm
MSWCFs-fflecause the list fails-to
includeonany constitaents that,have
been-iletected in,MSWLF.-leachate,
however, -the ,priority;poUutantilist was
rejected for,use,as the.GWES.
Tie Agenqy-oonaidereda third'Qption
of developing:aonew.liatiof'.constituents
for.-Ehase JamonltoringAt MS5/VLES. Tie
new list would.-have ^been corapfled&om
existing data on the types of toxic
compounds .that.-haveibeen'.detected in
leachate samples Aom iMSWLEs. -EPA'-s
current datatonMSWLFileachate are
Umitedtbsutsmdicate the ttremendous
range of ,constituents;and' concentrations
the 'analysis of leaiDhateisamples from
each.'MSWLE. -Ehis Approach would
allow DWJiersiand'qperators-ofMSWLFs
to limit'theu-analysesitojonlyithose
hazardous .constituents, present an the
leadhate of their landfill. The Agency
has the following concerns with -this
approach: (Ijltris unworkable for.sites
with no rleaehate collection jgystem
(including the majority of existing
landfillsj, ,(2),it does aot;account for
degradation processes soccurringiduring
(Constituent.'mjgration 'ihrough 'the
unsaturatedi zone and jground water,, ;and
(3) it would leQuiretperiodicflresampltng
of the leachate to accounilor ihe wide
variations ?in leachate -.quality -over :time.
The Agency is -interested in comments
on tthe efficaqyiof this appEoachifor
facilities that have leachate >collec*tion
systems.
The *jption;adopted;in .today's
proposal was io.usetthe AnpendixiH
consttituents.5ixtyaurje;of:ihe
constituents ;in Appemiix nihavBEbeen
foundjinMSWLF leachate. Thisaiumber
is tbasedtonlUrnited data, particularly i cor
hazardous organic (constituents; In
exammingithe variability of aubatances
appearingtinlandfillileachatB, samples
andLall'theinotentialxwaste streams sthat
may ibejplacedsm:MS\VU?s,tthe Agency
has concluded (that any abftthe 'Appendix
ncconstituentsipatentiaHycouldLbe
pcesBtttan ground'swaterrbenealhsan
MSWIiFatdevels 'Ihatanayipose itoeats
to rhuman health and dhe'enwironment.
The Agency irequestssjommBnts nn'ihe
conatituents ;pro,pDSEd for Phase!!
monitoring'atlMSiVWiEs.
Section 258.55(500 seiquires ttheMSVWLF
owner »r aperatoritoisample the*giound
water;incall:monitoring wells and
.-determine which, if jany.'of She
AppendiX;E[roonstituents are .preseritdn •
the gronna .waierat concentrsttions ahat
significant
Altogether, dataiwere received for59
Jandfills, with 37 Jandfills providing both
organic and inorganicileachate,analyses,
7 landfillsiJroviding'Only organic
analysis, and 15 landfiHsjrcaviding'.only
inorganic analysis. Sixty-louriazardous
organic constituents wHre;ldentified-as
well as 49 liazardous inorganic
constituents jand^ther^aramelers. In
most cases, ..the Hat of.constituents
analyzed for was lunlorown. SSB-theae
data^mayrnotiindicate the full-range of
constituents that-maybBtfoundiinJthe
Thus, this option was.rejected because
of data limitation, jsarticularlsr.'f or
hazardous -organic'.constituents.
The fourth qption iheAjgenqy
considered'.was dev,elqpingtsite*sp.eclfic
Phase;n.mDnitoringtconatitaer£ts-through
.
days sifter MggeringI!haBe,II.;IfithB
owrrer roriopeEatBrflDondludeSiOntthB
ixasis of 'ihe/Appendfa: n.isonstituent
scan thritaione iof 'the rconstituents
significantiy«xceed4iackgEOund .levels,
pursuant to § 258.54(d), the Statetmust
determine ithe {frequency tfoTsany
subsei}uent,'AppendiJi;II:consiitueHt
scans to be conducted'ataheMSWUF
duringitheaaativ-edifetorpost-closure
care.
:-Sectionl258]55(e):di:;today's;proposal
allows MSWLFs to revertSoaiprevious
phass of ground-water monitoring;8tfter
the owner or opeira'tor dBtermines ithat
there has not been a statistically
significant increase over thesbackground
levels of the relevant monitoring
parameters. This proposaLissimilarto
changes bemg!COH8iclered.for;ground-
-------
Augu
water monitoring under Subtitle G of
RCRA, and is particularly applicable to
Subtitle D, under which the practicable
capability of the owner or operator can
be considered. The Agency realizes that
it can be very difficult to prove that
error in sampling or analysis caused the
indication of a statistically significant
increase.above background levels of a
ground-water monitoring parameter. If
such an error were to occur and could
not be proven to be the cause, a unit
would be triggered into a higher and
more costly phase of ground-water
monitoring. The owner or operator
would be forced to pay for a more costly
monitoring program for an indefinite
time period, with no added benefit to
human health or the environment
Allowing a unit to revert to a previous
phase of monitoring when no
constituents have been detected above
background levels eases the financial
burden of the owner or operator without
harming human health or the
environment. A specific time period over
which monitoring must be conducted
before reverting to a previous
monitoring phase has not been
proposed, based on the concept that the
appropriate time period should be site-
specific. A minimum time period also
was not proposed, but the Agency
requests comments on the
appropriateness of a minimum time
period.
It should be noted that the criterion
for returning to Phase I monitoring (i.e.,
background levels for Appendix H
constituents) is consistent with those for
facilities that have never entered Phase
n monitoring. Therefore, an MSWLF
may not return to Phase I monitoring
merely by maintaining concentration
levels at the trigger levels that initiate
corrective measures assessment.
Instead, before returning to Phase I
monitoring, the concentration levels for
Appendix II constituents must be at or
below the background, which is the
level that initiates phase H monitoring
for a reasonable time period determined
by .the State.
If any Appendix n constituents are
detected at statistically significant
levels above background, § 258.55(f)
requires the owner or operator of the
MSWLF to notify the State of this fact in
writing within 14 days; and, within 90
days of the finding, he or she must
submit to the State a report containing
all data necessary for establishing a
ground-water trigger level.
Section 258.55(f)[2) of today's proposal
requires that each hazardous constituent
that is present at levels exceeding
background concentrations must be
analyzed from ground-water samples
the need for a
assessment of the ground-water
condition, necessitating more frequent
momtomig than for Phtse I. Thus? toe
Agency is proposing quarterly
monitoring at a minimum to provide the
earhes possible indication of when&e
tagger level has been excceeded. This
approach is consistent with the
approach taken in other Agency ground-
Wa,termtP.°^g programs. suchL
under Subtitle C of RCRA. More
frequent monitoring may be required by
the. State depending on site-specific
conditions, such as ground-water flow
rates and directions. The Agency
considered alternatives that would
require more stringent minimum
frequencies, but these alternatives
would have been unnecessarily
burdensome at sites where ground water
travels a distance of only a few feet per
year. Therefore, today's proposed
minimum frequency balances the need
lor early detection and thorough
assessment with the statutory need to
consider the "practicable capability" of
the regulated community.
In addition to the quarterly monitoring
for those constituents exceeding
background, § 258.55'fd) requires that
• each MSWLF monitor-other Phase II
constituents (Appendix II constituents]
on a periodic basis to determine if any
additional constituents have entered the
ground water at concentrations that
significantly exceed background levels.
The frequency for monitoring these
other Phase II constituents is determined
by the State. These periodic analyses
are essential for use in determining
whether the design of an ongoing
corrective action program must be
changed to accommodate the treatment
or removal of additional constituents.
The Agency considered requiring annual
Appendix II analyses at all MSWLFs,
but the Agency believes selecting an
appropriate frequency based on site-
specific factors is essential given that
Phase H constituent analyses may
approach $3,000 per sample. The
"practicable capability" of the owner or
operator needs to be considered. The
Agency's decision to allow State
determination of the frequency for
periodic Appendix H analyses also is
based on the fact that site-specific
conditions will have a significant impact
on the release of any new constituents
to the ground water from an MSWLF.
The State also must determine the
frequency for Phase H constituent
analyses during post-closure care for
Proposed Rules
those constituents thathave^ee^
background concentrations
wS-si&Ss&i
% Proposed Phase II monitoring-
reqm«.ments under 1 258.55(h)(4) allow
tte owner or operator to demonstrate
ttat an increase over the ground-water
trigger Jevel was caused by a sampling
or«nalytical error or by a source other
thaivthe MSWLF. The rationale for
inchidijra this demonstration in today's
proposes provided under,the
discusifion of the Phase I monitoring
program in this preamble.
S.jSectijbn 258.56 Assessment of.
Corrective Measures
An assessment of corrective measures
is requiiced whenever concentrations of
hazardous constitutents in the ground
water exceed trigger levels. Trigger
levels are health- and environmental-
based levels established by the State as
indicators for protection of human
health emd the environment, (see
preamble discussionior §258.52).
• The S'tate shall specify -the scope of
the corrective measures siudy. Factors
that generally may he appropriate are
listed hi § 258.56(c). The purpose of the
assessment is to study potential
corrective measures, In general, the
extensiveness of the assessment (i.e.,
the number and type of alternatives
evaluated) should be commensurate
with the complexity of the site. ;(The
reader iu directed to (the Background
Document for Subpart E for a more
detailed discussion of what may be
appropriate for specific situations.)
There may be .some situations where a
limited assessment is appropriate. For
example!, if the ground swater is known
to be Class ffl ground water (see
preamble discussion for § 258.57(fJ(2))
-------
33376^
end remediation will not be required,
*&SSXS£&S& Controls
to limit exposure.
35StetfE=F2£r
S±SSISES~E-
te»5SK
contaminant transfer, an
characterize the nature and extent of the
plume of contamination.
P Analysis of a remedy's performance.
reliability, and ease of implementation
mav Include on assessment of its
SSess in achieving intended
/upctions of containment, treatment,
remediation, or disposal of the
hazardous constituents and the degree
of protection afforded human health and
the environment. In addition,
consideration should be given to the
frequency and complexity of necessary
operation and maintenance and the
extent to which the technology has been
successfully demonstrated under
analogous conditions. The technical
feasibility for the remedial strategy
should also be considered in terms of
ability to construct and operate the
remedial technologies and the
availability of necessary treatment,
storage, or disposal services, and
capacity.
The Agency is particularly concerned
about potential cross-media impacts
(intermedia transfer of contaminants] ot
remedies, and, therefore, the Agency
specifically identified them as an area
that the State may require the owner or
operator to consider. Some remedial
technologies may cause secondary
impacts. For example, in some
circumstances, air stripping of VOCs
from ground water may release these
VOCs to the air unless specific
emissions control devices are installed
on the alt stripper.
In today's proposal, the State also
may require the owner or operator to
evaluate the timing of the potential
remedy (§ 258.56(c)(3)), including
construction, start-up, and completion
time. Timing will be important m_
distinguishing among remedies. The
State ultimately determines the
!ompSnce schedule: for final cleanup of
the ground water under i 258.57(d).
The owner or operator may be
required by the State to include cost
estimates for alternatives considered
[§ 258.56(c)(4)). Cost estimates will be
very important to the State when
approving the selected remedy. The
practicable capabilities of fee facility,
including fee capability to finance and
manage a corrective action program
may be considered by the State in
determining fee duration of fee clean-up.
Therefore, fee cost of fee remedy may
affect fee remedy selected and fee
timing of fee cleanup (see preamble
discussion of § 258.57(d)).
The owner or operator may be
required to consider institutional _
requirements under § 258.56(c)(5). For
example, local governments may have
specific requirements related to the
remedial activities feat may affect
implementation of fee remedies
evaluated. . ,
Finally, fee State may require fee
__ *«„ *« Qtrolnnto tnP m
jpinauy, uie *JIBW» *"-v *-?i—- - ...
owner or operator to evaluate fee public
acceptability of alternatives. The
consideration of community concerns is
a decision factor feat fee State will use
in selecting a remedy (see § 258.57 °)(5)).
Under fee proposed § 258.56(d), fee
State may require fee owner or operator
to evaluate one or more specific
potential remedies. These potential
remedies may include innovative
technologies. The State may know of
technologies feat have been successful
at other landfills wife similar
contamination problems. The proposed
§ 258.56(e) requires feat, after all
remedies have been evaluated, fee
owner or operator must submit a report
to fee State on fee assessments so that
fee State may choose which remedy
should be implemented. r
Under proposed § 258.56(f). if fee State
determines at any time feat human
health or fee environment are being
threatened by fee release of hazardous
constituents from fee MSWLF, fee State
may require fee owner or operator to
implement fee measures required in
proposed § 258.58 (a)(3) or (a)(4) (see
preamble discussion of § 258.58(a)).
4 Section 258.57 Selection of Remedy
and Establishment of Ground-Water
Protection Standard
The proposed § 258.57 outlines fee
general requirements for selection of
remedies for MSWLFs. As structured, it
establishes four basic standards feat all
remedies must meet and specifies
decision criteria that will be considered
by fee State in selecting fee most
appropriate remedy. In addition,
decision factors for setting schedules for
initiating and completing remedies are f
outlined, and specific requirements tor
establishing ground-water protection
standards, including requirements for
achieving compliance with them, are
contained in this section.
Proposed § 258.57(b) specifies that all
remedies must: Be protective of human
health and fee environment; attam
nround-water protection standards as
specified pursuant to § 258.57 (e) and (f);
control fee sources of releases so as to
reduce or eliminate, to fee maximum
extent practicable, further releases that
may pose a threat to human health or
fee environment; and comply wife
standards for management of wastes as
specified in §258.58(d).
These standards reflect fee major
technical components of remedies:
cleanup of releases, source control, and
appropriate management of wastes feat
are generated by remedial activities.
' The first standard—protection of human
health and fee 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 hot directly related to
ground-water protection, source control,
or management of wastes. An example
would be a requirement to provide
alternate drinking water supplies m
order to prevent exposure to releases to
around water used for drinking water.
Another example would be barriers or
other controls to prevent direct contact
wife the unit.
Remedies will be required to attain
" fee ground-water protection standards
feat will be specified for fee remedy by
fee State according to fee requirements
outlined below. TheGWPS for a remedy
often will play a large role in ,
determining the extent of and technical
approaches to fee remedy. In some ,
cases, certain technical aspects of fee
remedy, such as fee practicable
capabilities of remedial technologies,
may influence to some degree fee GWPS
feat are established. It is because of this
interplay between cleanup standards
and ofeer remedy goals and limitations
feat today's rule establishes
requirements for GWPS within the
overall remedy selection structure of
§ 258.57. Thus, fee standard setting
process and fee remedy selection
process occur concurrently wife both
processes affecting fee ofeer.
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Federal Rei*ffer/VoL 53. No. 168, Tuesday,August 30, 1988 / Proposed Rules 333??
Section § 258.57(b)(3) is the source
control standard for remedies. A critical
objective of remedies must be to reduce
further environmental degradation by
controlling or eliminating further
releases that may pose a threat to
human health and the environment. In
some cases, unless source control
measures are taken, efforts to clean up
releases may be ineffective. EPA is
persuaded that effective source control
actions are an essential part of ensuring
the effectiveness and protectiveness of
corrective actions at MSWLFs.
The standard of § 258.57(b)(3) requires
that further releases from sources of
contamination that may pose a threat to
human health or the environment be
controlled to the "maximum extent
'practicable." This qualifier is intended
to account for the practicable
capabilities of the owner or operator
and the technical limitations that may,
in some cases, be encountered in
achieving source controls. For some very
large MSWLFs. engineering solutions
such as treatment or capping to prevent
further leaching may not be technically
feasible or completely effective in
eliminating further releases above
health-based contamination levels. In
such cases, source control may need to
be combined with other measures, such
as plume management or exposure
controls, to be an effective and
protective remedy.
The Agency does not intend this
source control requirement to disrupt
Solid waste disposal at operating
MSWLFs that have contaminated
ground water. The Agency believes that,
until the MSWLF is closed with an
appropriate final cover (pursuant to
§ 258.40), other effective measures may
be implemented. For example,
depending on the source(s) of the
release(s), capping inactive cells or units
may help to control further releases. As
mentioned above, plume management,
and exposure controls also may be
needed, especially while the facility is
continuing to receive waste.
The concept of effective source
control as a remedial objective, as
expressed by this remedy standard in
§ 258.57(b)(3), is closely linked to the
CERCLA preference for Superfund
remedial actions that utilize "permanent
solutions and alternative treatment
technologies or resource recovery
technologies to the maximum extent
practicable."
The proposed remedy standard of
§ 258.57(b)(4) requires that remedial
activities that involve management of
wastes must comply with the
requirements for solid waste
management, as specified hi § 258.58(d)
in today's proposed rule. Remedies may
involve treatment, storage, or disposal
of wastes, particularly in the context of
source control actions. This standard
will ensure that management of wastes
during remedial activities will be
conducted in a protective manner. The
Agency requests comment on the four
proposed standards for remedies.
Proposed § 258.57(c) specifies general
factors to be considered by the State hi
selecting a remedy that meets the four
standards for remedies. These factors,
which generally are consistent with the
evaluation criteria specified in SARA,
are discussed briefly below. The Agency
requests comment on these factors.
These factors are meant to aid the
States in evaluating the data provided
by the owner or operator as a result of
the assessment of corrective measures.
The general decision factors are: (1) .
Long- and short-term effectiveness and
protectiveness, (2) reduction of future
releases, (3) implementability, (4)
practicable capability of the owner or
operator, and (5] community concerns.
The first two factors described under
§ 258.57(c) are directly linked to the
standards for the remedy. The long- and
short-term effectiveness and
protectiveness of the remedy is a
measure of whether human health and
the environment will be protected while
the remedy is being implemented and
once it is completed. It also is a measure
of whether the GWPS can be met. The
second factor, the reduction of future
releases'; should be used in evaluating
how well the source control standard
has been met. The practicable capability
of the owner or operator also may be
considered when evaluating to what
extent source control can be achieved.
The Agency believes that the
implementability of potential remedies
also must be considered by the State
when evaluating remedies. Factors that
may affect the implementability of a
remedy included: (1) The degree of
difficulty associated with constructing
the technology, (2) the expected
operationalreliability of the
technologies, (3) the availability of
necessary equipment and specialists,
and (4) the available capacity and
location of needed treatment, storage,
and disposal services.
The practicable capability of the
owner or operator is another remedy
selection factor. As described elsewhere
in this preamble, practicable capability
includes both economic and technical
capability of the owner or operator. The
consideration of practicable capability
allows the State to choose the remedy or
combination of remedies that can meet
the overall goal of protection of human
health and the environment. This may
affect the timing of corrective action,
and, therefore, practicable capability
has been listed as a factor for the States
to consider in establishing the cleanup
time frame [see preamble discussion of
§ 258.57(d)). In addition, as mentioned
previously, the practicable capability of
the oivner or operator may be
considered by the State in defining to
what extent the source of releases will
be controlled.
Community concerns is another factor
that the Agency believes must be
considered by the State when selecting
a remedy. It is very important that the
community has confidence in the
remedy, how it was chosen, and the
parry responsible for implementation.
The success of the corrective action
process with regard to community
involvement may significantly affect the
siting of future MSWLFs in that
community.
Any remedy proposal developed
durinj! the assessment of corrective
measures presented to the State for final
remedy selection must, at a minimum,
meet the four standards of § 258.57(b).
The State then will evaluate those
remedies. The decision factors
discussed above will be used by the
State in selecting the appropriate
remedy. The relative weight given to
any one of the factors will vary from
facility to facility. For example, short-
term effectiveness considerations may
be of particular concern where 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
factors will often play,a substantial role
in shaping remedies—some technologies
will require State or local permits prior
to construction, which may increase the
time needed to implement the remedy.
Proposed § 258.57{d) would require
the State to specify a schedule for
initiating and completing remedial
activities as a part of the selection of
remedy process. This provision gives the
States the flexibility to prioritize
MSWIF cleanups within their borders.
The Agency believes that the flexibility
these factors [described below) allow is
essenti al considering the practicable
capability of many MSWFs. Further, the
Agency believes mat the use of these
factors will not in,any way compromise
protection of human health or the
environment.
The .Agency is proposing that the
State consider numerous factors in
determining the cleanup time frame.
First, tlireats to human health or the
environment from exposure to
contamination during implementation ot
the corrective action program must be
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Federal Register / Vol. 53, No. 168. Tuesday, Augi^J>p. ^88
considered. Ground-water cleanup
should be hastened if protection of
human health and the environment
cannot be ensured. Current ground-
water users and actual or potential
ecological damages must be identified.
Second) the extent and nature of the
contamination should be considered to
determine what remedies and time
frames are technically feasible.
The resource value of the
contaminated aquifer is a third factor.
Resource value is broadly defined as the
value of the aquifer as a current and
future water supply for domestic,
industrial, agricultural, and other
beneficial uses. This provision allows
the States to balance the resource value
of the affected ground water against the
corrective action costs to determine the
corrective action time period. States
then can determine and require, at a
minimum, that owners or operators
implement the combination of
replacement and corrective actions that
most efficiently address the short- and
long-term protection of human health
and the environment. When evaluating
tho resource value of the aquifer, States
should consider the value of the regional
aquifer, not just the value of the portion
of the aquifer affected by the facility. In
addition, local values with respect to
maintaining uncontaminated aquifers
should be considered.
A fourth factor to be used by the state
in determining the corrective action time
period is the availability of treatment or
disposal capacity for any waste
managed during the corrective action
program. Capacity should be ensured
before removal or treatment of the
wastes or ground water begins. In
addition to ensuring capacity, the owner
or operator must also ensure that wastes
will be managed in compliance with
requirements in § 258.58{d).
The fifth and sixth factors concern
remedial technologies. New and
innovative corrective action
technologies are being investigated
continually and it may be appropriate
for the State to postpone ground-water
remediation if a new technology (i.e.,
one that currently is not available)
offers significant advantages over
current technologies. Along the same
lines, the State must consider the
practicable capabilities of existing
remedial technologies before setting up
a compliance schedule. For example, the
amount and complexity of construction
needed to implement a particular
remcdical technology could be an
important factor or the amount of time
that would routinely be needed to
achieve the GWPS given a specified
technology.
The States also may consider, in
dtermining a cleanup time schedule, the
practicable capability of the owner or
operator of the MSWLF. These
capabilities include both the economic
and technical capabilities of the owner
and operator to initiate the corrective
action program. As mentioned.
previously EPA does not intend to
tradeoff environmental or human health
protection for cost considerations. The '•
use of practicable capability as a
remedy decision factor was described
earlier. Using the practicable capability
of the owner or operator as well as other
cost considerations (e.g., discussed in
relation to resource value) in
combination with the other factors
described above to determine the
cleanup time frame, allows the State to
choose the combination of actions that
will effectively and erfficiently protect
human health and the environment and
ensure that ground-water remediation is
completed.
The proposed factors undr § 258.57(d)
would allow the State to accept a
combination of remedies to be
implemented in discrete phases. This
phased approach may affect the time
required to achieve the final cleanup.
Such an approach will ensure that
important environmental problems are
addressed first (interim measures may
also be used; see preamble discussion of
§ 258.58(a)(4)). This phased approach
may be frequently necessary at
operating facilities to prevent the
disruption of solid waste disposal. Initial
actions would always include steps to
prevent exposure to the contaminated
ground water (e.g. make alternative
water available). An initial remedial
step may be to install a pump and treat
system that would minimize further
migration of the plume. These steps
could continue until more active
remediation or source control could be
implemented.
Section 258.57(e) of today's proposal
requires the State to establish a GWPS
for each Appendix II constituent
detected above trigger levels. The
GWPS represents constituent
concentrations that remedies must
achieve. The GWPS is set on a
constituent-specific basis during the
remedy selection process.
The State must set the GWPS within
the overall context of the remedy
selection process. During the assessment
of corrective measures (§' 258.56) the
owner or operator should design
remedies to meet target cleanup levels.
These target cleanup levels may start
out as trigger levels, but, as pertinent
site-specific information becomes
available, the State should modify the
target levels. The remedies analyzed by
the owner or operator should generally
be designed to meet the target levels.
The State will ultimately select a
remedy and set a ground-water
protection standard that must be
achieved. ,
The State's primary consideration in
setting ground-water protection
standards will be to ensure that human
health and the environment are
protected. As in the case of trigger
levels, the State should generally use
promulgated health-based standards
(e.g., MCLs) and GWPS, where they are
available.
Where MCLs or other such standards '
are not available, the State may rely on
RfDs and RSDs in developing ground-
water protection standards (see
preamble discussion of Determination of
Trigger Levels for more information
about RfDs and RDSs). For ,
noncarcinogens, the State may set a
level based on the RfD. Sta'tes have
flexibility to select a GWPS within the
protective risk range (see preamble
discussion of risk range alternatives
being considered and of Determination
of Trigger Levels).
A variety of site-specific and/or
remedy-specific considerations may
enter into the determination- of where
within the cancer risk range the ground-
water protection standard for a given
hazardous constituent will be
established. The most appropriate level
for cancer risk must be determined
through an analysis of factors related to
exposure, uncertainty, and technical
limitations. Proposed § 258.57(e) lists
five factors the State may consider in
establishing GWPSs.
The first site-specific factor is multiple
contaminants in the ground water. To
ensure that individuals exposed to
ground water will be protected, it may
be necessary to consider the risks posed
by other constituents in the ground
water before a GWPS for a single
constituent can be extablished. In
considering the risks posed by multiple
contaminants, the State should follow
the procedures and principles
established in the Agency's "Guidelines
for the Health Risk Assessment of
Chemical Mixtures" (51 FR 34014) issued
on September 24,1986. All other factors
being the same, the GWPS for a
constituent present in ground water that
is contaminated with other constituents •
that pose significant risks should be
established at a lower concentration
than if that constituent were the sole
-contaminant in the ground water. Taken
as a whole, once final remediation is
completed, ground water must not pose
a risk greater than 1X«T4. To the extent
practicable for new MSWLFs," the
overall risk level for the ground water
(not for each constituent) should be
equivalent to the risk level used in
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1988 / Proposed Rules
33379
meeting the design standard (see
preamble discussion of § 258.40).
The second factor, is; actual or
potential exposure threats to sensitive
environmental receptors. Frequently,
levels set for protection of human health
also will 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 or threatened or
endangered species' habitats should be
considered in establishing the GWPS.
The next factor is other site-specific
exposures to the contaminated ground
water. For example, residents living
near a municipal solid waste landfill
may receive unusually high exposures of
hazardous constituents from other
sources (e.g., lead from a lead smelter).
These other exposures should be
considered when developing the GWPS.
The last consideration is remedy-
specific factors. The State must consider
the reliability, effectiveness,
practicability, and other relevant factors
of the remedy when establishing a
GWPS. For example, a remedy that can
treat constituents in ground water down
- to concentrations posing a lX10~5risk
level may be selected in preference to
another remedy that might achieve a
1 X1(T 6 risk level, but that relies on '
technology that has not been
successfully demonstrated or may be
unreliable for other reasons.
There also are technical limitations
that must be considered, in addition to
scientific information about the hazards
to human health and the environment, in
establishing ground-water protection
standards. For example, GWPSs should
not be set lower than detectable levels.
Proposed § 258.57(e)(5)(i) establishes
that a GWPS houldnot be set below
background levels unless the State
determines that cleanup to levels below
background is necessary to protect
human health or the environment. In
general, the Agency believes that it may
not be reasonable to require the owner
or operator to reduce the concentrations
of hazardous constituents to levels
below background. In many cases such
a reduction would not be technically
feasible. Today's proposal, however,
does not allow MSWLFs located in
contaminated areas to ignore
incrementally significant facility
contributions to the contamination
unless a determination is made under
proposed § 258.57(f) that remediation is
not required.
Proposed § 258.57(f) identifies three
situations in which the State may decide
not to require cleanup of a release to
ground water of hazardous'waste or
hazardous constituents from an
MSWLF, thus obviating the need to
establish ground-water protection
standards. These situations are limited
to cases where there is no threat of
exposure to releases from MSWLFs, or
cases where cleanup will not result in
any reduction in risk to human health or
the environment. In any case, the State
may impose under § 258.57(g) source
control requirements to minimize or
eliminate further releases from the
MSWLF even if remediation is not
required. The Agency does not believe
that continued further degradation of the
environment is warranted, even in those
situations where cleanup may not be
required.
In some cases, MSWLFs releasing
hazardous constituents to the ground
water will be located in areas that
already are significantly contaminated.
Where releases from the MSWLFs are
trivial compared to the overall area-
wide contamination, or where remedial
measures aimed at the MSWLF would
not significantly reduce risk, EPA
believes that remediation of releases
from the MSWLF would not be
necessary or appropriate. In these
situations, proposed § 258.57(f)(l) would
allow the facility owner or operator to
provide the State information
demonstrating that remediation would
provide no significant reduction in risk.
If the demonstration were made, the
State should determine that remediation
is not necessary.
For example, ground water below a
leaking MSWLF might be heavily
contaminated from off-site sources. In
this case, removal of the MSWLFs
contribution to the contamination might
have very limited benefit, particularly if
that contribution was relatively minor.
Control of the MSWLF releases might do
very little, in such a case, to improve the
overall situation in the area, yet (in the
case of an operating unit) might be
extremely burdensome to the owner or
operator.
Two points should be stressed hera,
however. First, the facility owner or
operator would be required to remediate
the ground water where it could have a
significant effect on reducing risks—for
example, as part of an area-wide
cleanup strategy. Second, in any case,
under § 258.57(g) source control may be
required to prevent further releases.
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 by the State. However, the Agency
seeks comment on whether a more
specific definition is necessary for the
purposes of this rulemaking.
Under proposed § 258.57(f)(2), the
State may determine that a hazardous
constituent that has been released from
an MSWLF to ground water does not
pose a threat to human health and the
envirojiment and, therefore, does not
require! remediation 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 are migrating or
are likely to migrate in a
concentration^) that represents a
statistically significant increase over
background concentrations.
In interpreting whether the aquifer
meets these criteria, the State may use
the approach outlined in the Agency's
Ground-Water Protection Strategy
(August 1984) as guidance. Typically,
Class III ground waters will be
considered to meet the requirements
specified in § 258.57(f)(2)(i). Class HI
ground waters are ground waters not
considered potential sources of drinking
water. They are ground waters that are
heavily saline, with TDS levels over
10,000 nig/1, 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. The
need to immediate Class III ground
waters should be assessed on a case-by-
case basis.
Proposed § 258.57(fj(3) would allow
the State to make a determination that
remediation of a release is not required
when remediation is technically
impracticable or when remediation
presents:,unacceptable cross-media
impacts. |Such a determination may be .
made, few example, in some cases where
the nature of the hydrogeologic setting
would prevent installation of a ground-
water pump and treat system (or other
effective bleanup technology), e.g., in
Karst formations or where heavily
fractured bedrock lies under the facility.
In these situations, the installation of
such a system could possibly increase -
environmental degradation by
introducing the contaminant into ground
water thait was not previously affected
by the re] ease. The Agency is persuaded
that in this and other situations
remediation should not be required. The
Agency isi specifically soliciting
comment today on the types of
situations that might warrant a
determination that remediation of a
release is technically impracticable or
presents unacceptable impacts and -
would nol:, therefore, be required.
Proposed § 258.57(h) outlines the
Agency's proposed approach to
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33380
establishing conditions the owner or
operator must MM to achieve and
demonstrate compliance with the GWPS
established by the State during the
remedy selection, process.
First, the GWPS must be achieved at
all points within the plume of
contamination that lie beyond the
ground-water monitoring well system
established under § 258.51[a). The
ground-water monitoring well system is
established at the boundary chosen for
the design (Le.. at the unit boundary or a
State alternative boundary that does not
exceed 150 meters from the waste
management unit boundary and is on
land owned by the owner or operator of
the MSWLF (see preamble discussion of
1258.51(a)). It is logical that cleanup be
required up to the boundary for which
the facility was designed to meet a
health-based risk level.
The Agency also is proposing under
§ 258£7(hX2) that the State specify in
the remedy the length of tune during
which the owner or operator must
demonstrate that concentrations of
hazardous constituents have not
exceeded specified concentrations in
order to achieve compliance with
GWPSs. Under existing Subtitle C
regulations (§ 284.100), the Agency has
required that facility owners or
operators remediating ground-water
contamination from regulated hazardous
waste units continue corrective action
until the dedignated GWPSs have 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 GWPSs
have been achieved by Imposing a
uniform time for demonstrating
compliance. Consequently, the Agency
is considering proposing changes to the
Subtitle C program:
In today's proposal for MSWLFs, the
Agency is proposing that the State
specify the length of time required to
make such a demonstration on a site-
specific basis. As described under
proposed f25B-57(hK2), the State may
consider four factors in setting this
timing requirement: (1) The extent and
concentration of the release, (2) the
behavior characteristics of the
hazardous constituents in the ground
water. (3) the accuracy of the monitoring
techniques, and (4) characteristics of the
ground water. The Agency believes that
consideration of these factors will allow
the State to set an appropriate time
period for demonstrating compliance
with GWPSs rather than relying on an
arbitrary time period for all facilities or
all situations at the same faculty.
One example of how these
considerations might affect a decision
on the time a ground-water protection
standard must not be exceeded to
demonstrate compliance is given here.
The Agency expects that pump and treat
systems will be necessary at many
MSWLFs. Experience in the RCRA
Subpart F program (which addresses
releases of hazardous constituents to
ground water from regulated hazardous
waste units) has shown that continuous
operation of a pump and treat system
may interfere with the owner or
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.
5. Section 258.58 Implementation of the
Corrective Action Program
Implementation of a corrective action
program is required when hazardous
constituents are detected at levels
higher than the GWPS. Several activities
are required of the owner or operator
under proposed § 258.58. First, a
corrective action ground-water
monitoring program is required under
proposed § 258.58(a)(l). This program
must meet the requirement of the Phase
II monitoring program (§ 258.55),
demonstrate the effectiveness of the
remedy(s), and demonstrate compliance
with the GWPS.
Second, under § 258.58(a){2), the
owner or operator must implement the
remedyCs) selected by the State under
§ 258.57. As described under § 258.57,
the "remedy" encompasses not only the
technology to be used to remediate the
ground water (if remediation is to be
conducted), but also the GWPSs to be
reached and the time the owner or
operator has to reach the standards (see
preamble discussion of § 258.57).
Next, under § 258.58(a)(3), the owner
or operator must notify all persons who
own or reside on the land that overlies
any part of the plume of contamination.
The State may require the owner or
operator to notify such persons any time
the trigger level has been exceeded (i.e.,
before the GWPS has been established)
if the State determines it necessary to
protect human health or the
environment (see § 258.58(fJ).
Under the proposed § 258.58(a)(4) the
State may require the owner or operator
to conduct interim measures at an
MSWLF whenever the State determines
such actions are necessary to protect
human health or the environment. The
.interim measures would serve to
mitigate actual threats and prevent
potential threats from being realized
while a long-term comprehensive
response can be developed. Interim
measures should, when possible, be
consistent with the expected final
remedy. The State should consider the
immediacy and,magriitude of the threat
to human health or the environment as
primary factors hi determining whether
an interim measure(s) is required.
Proposed § 258.58(a)(4Ki)-Cvii) lists
factors that the State may consider hi
determining whether an interim measure
is required.
Interim measures may encompass a
broad range of actions. For example, an
owner or operator responsible for
contamination of a drinking water well
may be required to make available an
alternative supply of drinking water as
an interim measure in an effort to
protect human health. This replacement
action could be temporary or permanent.
The duration of the period over which
replacement supplies must be provided
can affect the type of action selected.
Replacement actions may include
hooking up affected aquifers, relocating
wells, and treating contaminated ground
water at the point of use.
During the implementation stage,
other factors may arise that make thi
chosen remedy technically
impracticable. For example, the
unexpected occurrence of an area of
unstable soils may render the chosen
source control remedy impossible to
construct. Proposed 1258.58(b)
describes factors the State must
consider in making such a
determination. In these instances, the
State may require that the owner or
operator implement cither alternatives to
control exposure to residual
contamination as described under
§ 258.58(c).The State also may require
the owner or operator to implement
other source control options and other
equipment, unit, device, or structure
decontamination activities. The State
will evaluate these alternative activities
for their technical practicability and
their consistency with the overall
objectives of the original remedy. The
GWPS will not be changed; however,
the State may want to adjust the time
allowed for completion of the remedy.
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S3381
Proposed § 258.58(d) requires that
wastes generated during the
implementation of corrective action be
managed in a manner that is protective
of human health and the environment. In
particular, the waste management
practices must be in compliance with all
applicable RCRA requirements.
According to proposed § 258.58(e), the
remedy is considered complete when the
GWPS has been achieved according to
the requirements of § 258.57(h) and all
other actions required in the remedy
have been completed (e.g., source
control measures). After the required
remedy is complete, the owner or
operator must submit a statement that
certifies that the remedy has been
completed in accordance with
requirements under § 258.58(e). In
addition to the owner or operator's
signature the certification must contain
the signature of an independent
professional engineer geologist, or other
appropriate technically trained person.
According to § 258.58(g), after the State
receives the certification and is satisfied
that the remedy is complete, the State
releases the owner or operator from the
requirements for financial assurance for
corrective action.
The Agency considered an alternative
approach to the corrective action
program proposed today. The
alternative would involve the following
steps. First: the owner or operator would
be required to do three activities: (1)
Report to the State any concentration of
hazardous constituents in the ground
water above trigger levels, (2)
investigate the nature and extent of the
contamination, and (3) take all
necessary actions to abate any
immediate risks to human health and
the environment. Second, after the
owner or operator submitted the results
of the investigation, the State would
assess, site-specifically, the risks to
human health and the environment
posed by the ground water
contamination. Based on this
assessment, the State would set site-
specific requirements for clean up of the
ground water (including cleanup levels).
Next the owner or operator would be
required to submit to the State for
approval a plan for meeting the cleanup
requirements. The owner or operator
then must implement the approved plan.
Modifications to the plan would be
allowed, if needed, based on site-
specific considerations. The approach
would present fewer specific Federal
requirements for cleanup. The Agency
requests comment on this alternative
approach as well as the proposed
corrective action requirements
discussed above.
X. Effective Date, Implementation, and
Enforcement of the Revised Criteria
Subtitle D of RCRA, as amended by
HSWA in 1984, requires the
Administrator to revise the Criteria for
sanitary landfills under § 4004(a) and
the solid waste management guidelines
under section 1008(a) for facilities that
may receive HHW or hazardous wastes
from SQGs. Subtitle D also contains
specific requirements with respect to the
implementation and enforcement of the
revised Criteria for facilities that may
receive these wastes. Of particular
significance is the provision in § 4005(c)
requiring that States adopt and
implement, within 18 months of the
promulgation of the revised Criteria, a
facility permit program or other system
of prior approval to ensure compliance
with the revised Criteria. In addition,
this section provides that "hi any state
that the Administrator determines has
not adopted an adequate program * * *
the Administrator may use the
authorities available under section 3007
and 3008 of [Subtitle C] to enforce the
prohibition contained in subsection (a)
of this section with respect to such
facilities." A discussion of the issues
regarding the implementation and
enforcement of the revised Criteria and
the options the Agency is considering
for addressing these issues is set forth
below.
A. Effective Date of the Revised Criteria
EPA today is proposing that the
revised Criteria become effective 18
months after their promulgation. The
Agency considered an alternative two-
stage approach, which is described
below, but decided that 18 months is the
most appropriate time period for several
reasons.
1. Eighteen-month Period
First, the 18-numth time period would
coincide with the period within which
States, under section 4005(c) of RCRA,
are to adopt and implement a permit
program or other system of prior
approval to ensure that facilities comply
with the revised Criteria. Congress
provided this 18-month period after the
promulgation of the revised Criteria to
provide States adequate time in which
"to adopt new or revise existing
applicable-State standards and to
institute a permit process for ensuring
facility compliance. Because the States
are given the lead responsibility for
implementing the revised Criteria under
these provisions, EPA believes it is
critical to set an effective date for the
revised Criteria that coincides with the
date the States are required by RCRA to
have their implementation mechanisms
in place.
Second, the 18-month period would
provide MSWLF owners and operators
with sufficient time to take the
necesuary measures at their, facilities to
bring them into compliance. EPA
recognizes that certain of the revised
Criteria proposed today may require
substantial efforts on the part of the
facility owner and operator both in
modifjjdng management practices at an
existiiig MSWLF and in planning full
compliance for a new one. The fact that
most MSWLFs are owned and run by
local governments, which have limited
resources, also is a consideration.
Congress directed EPA to take into
account the "practicable capability" of
facilities hi revising the Criteria. EPA
believes that the proposed 18-month
period for allowing MSWLFs to come
into compliance recognizes the
practicable capability of MSWLFs to
meet certain of the revised Criteria.
Although EPA recognizes that some of
the revised Criteria could be
implemented in shorter periods of time,
i.e., she or 12 months, EPA believes that
a uniform effective date of 18 months
would minimize confusion on the part of
the regulated community. Also, while
the 18-month period before the effective
date proposed today would postpone
application of the revised Criteria to
MSWIFs, it would not leave these
facilities unregulated. The current part
257 Criteria and applicable State
standards would remain in effect for
these facilities until the revised Criteria
become effective. In addition, some
States may adopt the revised Criteria,
making them effective under their own
authorities, before the 18-month period
expires.
EPA recognizes that there are some
limitati.ons with this approach. EPA is
concerned that the 18-month period
between the promulgation and the
effective date of the revised Criteria
might allow some MSWLFs to close to
avoid meeting the new requirements.
The Agiency does not intend for this
period to be a window of escape for
marginal MSWLFs. Experience shows,
however, that MSWLFs do not open and '
close overnight. In fact, the long
operating lives of most existing
MSWLFs and years of advance planning
needed for siting and permitting new
facilities significantly mitigate against
such actions. The Agency is aware that
some closures may occur, however, and
intends to work with the States to guard
against closures performed in an
unsatisfactory manner that may pose
threats to human health and the
environment.
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Federal Register /Vol. 53, No. 168. Tuesday, August 30. 1988 / Pf°P°sed ,
2. Two-stage Approach
The 18-month approach would
preclude enforcement of the revised
Criteria through the citizen suit
provisions of RCRA § 7002 pending their
becoming effective. Thus, for 18 months,
citizens will be unable to use RCRA to
enforce the revised Criteria. For this
reason, EPA la considering the option of
establishing two stages of effective
dates. The first stage of effective dates
would be for only those requirements
that can be implemented by the facility
owner or operator in less than 18
months and are self-implementing on
their face, thus, leading themselves to
more immediate effective dates. The
effective date would be set at six or 12
months after the promulgation date as
appropriate for the specific requirement.
Tho self-implomenting provisions of this
rule include the general operating
criteria such as the liquids management
restrictions, the disease vector and
explosive gas controls, recordkeeping,
and closure and post-closure planning
requirements. The second-stage
effective date would be limited to those
requirements that require interactions
with or determinations by the State and
substantial efforts on the part of the
facility owner or operator for effective
implementation. These requirements
include the ground-water monitoring
and corrective action requirements. The
two-tiered approach would maximize
the use of citizen suit provisions during
the 18-month period because some of the
requirements would be in effect sooner,
i.e., in 012 months; however, this
approach runs the risk of causing
considerable confusion on the part of
regulated facilities and inconsistent
application of the revised Criteria
nationwide.
Although EPA has decided to propose
an effective date for all the revised
Criteria of 18 months after the date of
promulgation, EPA specifically solicits
public comment on the alternative two-
stage effective date approach described
above.
B. Review of State Permit Programs
Section 4005{c) of RCRA, as amended
in 1984 by HSWA, requires the
Administrator to determine whether
each State has developed an adequate
permit program or other system of prior
approval and conditions to ensure that
each solid waste disposal facility that
receives HHW or SQG hazardous waste
will comply with the revised Criteria.
The Administrator also is given the
discretionary authority to preform these
reviews in conjunction with the reviews
of State solid waste management plans
under RCRA §4007. ,
The Agency solicits comments
concerning the most appropriate means
for determining the adequacy of State
permit or other prior approval programs.
Issues include whether the Agency
should confine its review to
assessement of a State's permit or other
prior approval program or whether the
Agency should expand this review to
include all the components of the State's
solid waste management plan. Under
the first option, the Agency only would
review the State's permit or approval
program that incorporated the revised
Criteria. The Agency's review of the
State program would be limited to that
portion of the State's Subtitle D
program. The Agency recognizes that an
expanded review under the second
option would provide the State with the
flexibility to present additional elements
of its solid waste management'program,
outside of the permit or other prior
approval program, that help ensure the
proper management of solid waste
disposal facilities. In addition, this
broader evaluation would provide the
Agency with a better understanding and
appreciation of State implementation
activities under Subtitle D.
The latter option, however, would
require all of the States to either develop
or modify their solid waste management
plans to reflect the revised Criteria. The
development and/or modification of
these plans is a lengthy, and resource-
intensive process. The States may not
be able to meet the HSWA requirement
to adopt and implement a permit
program or other system of prior •
approval within 18 months from
promulgation of the revised Criteria if
they also must revise their solid waste
management plans. ,
Depending on the outcome of the
above issues, the Agency may need to
modify the Guidelines for Development
and Implementation of State Solid
Waste Management Plans [40 CFR Part
256), which delineate the requirements
and procedures for State solid waste
management plan review. The current
Part 256 guidelines comprehensively
address program requirements, solid
waste management plan submittal
procedures, organizational issues,
permit programs, legislative and
regulatory authorities, and public
participation requirements. The Agency
may need to modify Part 256 to clearly
specify the Agency's evaluation criteria
and review procedures for the revised
Subtitle D Criteria.
There are two other issues on which
the Agency specifically requests
comments. The first issue relates to
what evaluation criteria the Agency
should use to determine the adequacy of
State permit programs. One option is for
the Agency to base its determination of
program adequacy on the content of the
State's statutory and regulatory
requirements. Under this approach, the
Agency would develop evaluation
criteria for determining whether these
State requirements ensure that the
revised Criteria are met.:
On the other hand, the Agency could
assess State programs on the basis of
legislative and regulatory mechanisms
together with an evaluation of program
effectiveness. This review would include
an assessment of the State's past
performance (i.e., enforcement,
permitting) in managing solid waste
disposal activities. In particular, the
Agency would consider State resource
and technical capabilities in evaluating
State program adequacy. .
The second issue concerns the extent
of public participation that should be
provided for in the Agency's review of
State program adequacy. The Agency is
soliciting comments on whether there
should be opportunities for public
review and comment on the Agency's
evaluation of the adequacy of State
solid waste permitting programs or other
aspects of the State's solid waste
management plan. While the Agency
recognizes that such participation
opportunities may significantly extend
the review period, EPA nevertheless is
interested in providing such
opportunities when appropriate. EPA
will publish a more specific proposal
addressing these issues at a later date..
C. Enforcement of the Revised Criteria
States that have adopted the revised
Criteria under State law may enforce
them in accordance with State
authorities. Under today's proposal,
there would be no authority for EPA
enforcement of the revised Criteria until,
18 months after the date of promulgation
of the revised Criteria, the Agency
determines that a State's program is
inadequate. Also, citizens would be
" precluded from enforcing the revised
Criteria via citizen suits until the
Criteria become effective.
1. Citizen Suits
As with the Part 257 Criteria, citizens
may seek enforcement of the Part 258
revised Criteria (independently of any
State program for their enforcement) by
means of citizen suits. The citizen suit
provisions of RCRA contained in section
7002 provide, an important mechanism
for ensuring compliance with the
requirements of the statute and its
implementing regulations. They
authorize individuals, environmental
groups, and local governments, among
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1988 / Proposed Rules
33303
others, to bring legal actions for
noncompliance with RCRA
requirements. Thus, once the revised
Criteria become effective, they have the
full force of law and may constitute the
basis for citizen enforcement actions
against facilities that fail to comply.
Citizens would be able to bring actions
against facilities for failure to comply
with the Criteria and actions against
States for failure to develop and
implement permit or other prior
approval programs as required by RCRA
section 4005.
2. Federal Enforcement
Section 4005(c)(2) of RCRA, as
amended by HSWA in 1984, provides
authority for EPA enforcement of the
revised Criteria under authority of
sections 3007 and 3008 of Subtitle C.
This provision is significant in that it
represents the first authority for EPA
enforcement of regulatory requirements
under Subtitle D. According to section
4005(c)(2), EPA enforcement is
contingent on an EPA determination
that a State has not adopted an
adequate permit or other prior approval
.program to ensure the compliance of
facilities with the revised Criteria by 18
months from the date of promulgation of
the revised Criteria. Having made this '
determination, EPA may use the
inspection and enforcement authorities
under sections .3007 and 3008 to enforce
against facilities failing to comply with
the revised Criteria. Disposal of solid
waste at facilities that do not comply
with the revised Criteria constitutes
open dumping, These authorities provide
EPA with the necessary tools to enforce
Subtitle D's prohibition against open
dumping.
EPA expects the States to assume the
primary responsibility for implementing
and enforcing the revised Criteria, and a
major EPA enforcement program for
Subtitle D is not envisioned. If States
fail to assume their responsibility with
respect to the revised Criteria, however,
EPA may step in to ensure compliance
with Part 258 as necessary to protect
human health and the environment. As
explained above, EPA is soliciting
comments, on the criteria and
procedures that it should use to
determine whether a State has adopted
an adequate program.
EPA has determined that it is
necessary to formulate an enforcement
strategy with respect to the revised
Criteria and welcomes public comment
on the overall role of EPA enforcement
under Subtitle D, the proper elements of
an enforcement policy for ensuring
compliance with the revised Criteria,
and strategies for targeting MSWLFs
that pose the greatest threat to human
health and the environment. EPA is
soliciting public comment on the specific
circumstances and situations of facility
noncompliance with the revised Criteria
that should precipitate direct EPA
enforcement actions. In addition, the
Agency is particularly interested in
comments on circumstances under
which the Agency should act to enforce
criteria once the Administrator has
determined that the State's program is
inadequate pursuant to section
4005(c)(l)(C).
D, Other Implementation Issues
1. Implementation Strategy
In conjunction with the development
of this rule, the Agency is preparing an
implementation strategy. This strategy
will serve as a planning document for
EPA and the States in understanding
what actions are necessary to modify
the management of their regulatory
programs to accommodate the revised
Criteria. This strategy is designed to"
limit future implementation problems by
anticipating potential problems or
obstacles and crafting implementation
options to resolve or minimize these
issues before they emerge.
The Agency currently is identifying
implementation issues and needs
concerning permitting, compliance
monitoring, and enforcement activities;
public education and outreach activities;
guidance and training needs; resource
needs; and EPA/State roles and
responsibilities. In particular, the
Agency requests comments on the
following implementation concerns: (1)
What types of education-outreach
programs are needed for State and local
officials, the regulated community, and
the general public? (2) In what areas is
there a need for guidance and training?
What types of technical assistance
activities are needed? (3) What is an
appropriate and practical EPA role if the
States do not adopt and implement the
revised Criteria?
The Agency also solicits comment on
whether additional issues should be
considered in developing this strategy.
2. Co-disposal of Sewage Sludge
One of the major disposal practices
for sewage sludge is disposal at a
municipal solid waste landfill.
Approximately 6,800 POTWs dispose of
.their sewage sludge in this manner. By
promulgating the Part 258 requirements
jointly under RCRA and CWA.section
405, questions arise as to the extent to
which the Part 258 criteria would be
implemented through NPDES permits
issued to POTWs. Under RCRA Subtitle
D [section 4005(c)), the Part 258 criteria
are to be imposed by States on the
owner or operator of an MSWLF. States
are to impose the criteria by a system of
prior approval and conditions, such as
issuance of a permit to the MSWLF. The
Agency has selected this approach to
reconcile the two programs in a way
that would minimise duplicative
regulation while best ensuring complete
coverage under both statutes. This
approach would be consistent with
section 1008(b) of RCRA, which requires
EPA to integrate the provisions of RCRA
for purposes of administration and
enforcement, and to avoid duplication to
the maximum extent practicable, with
the appropriate provisions of the CWA
and other environmental laws
administered by EPA.
Under this proposal, the Part 258
criteria applicable to the characteristics
of sewage sludge that must be met if
sewage sludge is placed in an MSWLF
would be implemented through permits
issued to POTWs pursuant to section
405(f) of the CWA. The Part 258 criteria
applicable to the landfill site would be
implemented under the RCRA Subtitle D
program. This would mean that the
POTW permit would prohibit the
disposal in an MSWLF of sludge found
to be hazardous (§ 258.20), and would
require that the sludge pass the Paint
Filter liquids Test (§ 258.28). The POTW
permit also would prohibit the POTW
from sending its sludge to MSWLFs that
are not in compliance with the
' applicable Federal and State
regulations. Thus, to obtain a permit
authorizing disposal of sludge at a
landfill, the POTW would have to
ascertain that the MSWLF either has a
permit under Part 258 or otherwise is
authorized to operate as an MSWLF by
the State in which it exists, as
prescriibed by RCRA.
EPA believes that this implementation
schemei fulfills the goals and policies of
both RCRA and the CWA and is a
rational way to reconcile overlapping
programs. EPA also considered separate
implementation of the Part 258 criteria
under each program. Under the sludge
management program of the CWA, this
method would involve implementation
of all Piirt 258 criteria, including those
applicable to location, design, and
operation of the landfill, through permits
issued to the POTWs. The Agency
decided; against this approach for two
reasons. First, it would establish
duplicaltfve coverage without apparent
corresponding environmental benefits.
Typically, sewage constitutes a small
proportion of the wastes disposed at an
MSWLF. Compared to other wastes sent
to an MSWLF, such as household
hazardous waste and hazardous waste
from veiry small quantity generators,
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
sewage sludge is unlikely to be the
source of environmental problems at the
landfill. In fact, the presence of sewage
sludge in a co-disposal facility may even
improve the quality of the leachate at
least in the short run (Ref. 15). Second,
holding POTWs liable for compliance by
the landfill with the Part 258 standards
may not be appropriate because other
solid waste contributors are not
similarly held liable.
EPA invites comment on whether the
approach proposed here is an
appropriate and effective means to
ensure proper management of sewage
sludge disposed of in a landfill.
XI. Regulatory Requirements
A, Executive Order No. 12291
1. Purpose
The Agency estimated the costs,
benefita, and economic impacts of
today's proposed rule. These analyses
are required for "major" regulations as
defined by Executive Order No. 12291.
The Agency also is required under the
Regulatory Flexibility Act to assess
small business impacts resulting from
the proposed rule. The cost and
economic impact analyses also are a
measure of the "practicable capability"
of facilities to comply with the proposed
rule.
The cost, benefit, and economic
impact results indicate that today's rule
is a "major" regulation and it would
likely impose differential impacts on a
significant number of small entities. This
section of the preamble discusses the
results of the analyses of the proposed
rule as detailed hi the draft Regulatory
Impact Analysis of Proposed Revisions
to Subtitle D Criteria for Municipal Solid
Waste Landfills. The draft RIA is
available hi the public docket. This rule
was submitted to the Office of
Management and Budget (OMB) for
review as required by E.O. No. 12291.
2. Regulatory Alternatives
E.O. No. 12291 requires EPA to
estimate the costs and benefits for the
proposed rule as well as any viable
alternatives. Several current provisions
(e.g., performance standards for existing
units, post-closure care, ground-water
monitoring parameters) of the proposed
rule do not exactly reflect what was
analyzed in the RIA. For this reason, the
results presented in this section and the
RIA may understate the fraction of
existing landfills requiring more
stringent covers (and the resulting costs
of these covers), overstate costs for
post-closure care, and understate the
sampling coats for ground-water
monitoring. Nonetheless, the Agency
believes the basic conclusions of the
draft RIA are accurate estimators of the
effects of the proposed rule.
In addition to the proposed rale, EPA
analyzed the effects of three regulatory
alternatives hi the RIA. The analysis of
the regulatory options provides a
comparison of the proposed rule in the
context of other regulatory scenarios.
The alternatives predominantly differ
with respect to the stringency and
uniformity of the containment and cover
requirements. Corrective action (the
benefits of which currently are modeled
for new units only) and extended post-
closure care are required for all
regulatory options.
Alternative 1 consists of a uniform set
of technology-based requirements that
are imposed on all MSWLFs irrespective
of location or migration potential. This
alternative has the most stringent design
requirements and essentially reflects the
Subtitle C regulations for land disposal.
New units are required to have a double
composite containment system (i.e., two
synthetic liners over a clay liner) with •
two LCSs and a composite cover. New
and existing units are required to close
with a composite cover. Ground-water
monitoring (as detailed in Subpart F of
40 CFR Part 264), gas monitoring, run-on
and run-off controls, and exclusion plan
for nonmunicipal solid waste, corrective
action, and extended post-closure care
are required for both new and existing
units under this regulatory alternative.
Alternative 2 requires cover and
containment designs based on the
migration potential at the site. This
categorical approach is described hi .
Section D of this preamble. General
facility standards are identical to those
for the proposed rule. Corrective action
and extended post-closure care are
required for all units.
Alternative 3 imposes ground-water
monitoring, corrective action, and
extended post-closure care on both new
and existing units. This alternative is
similar to the statutory minimum
described under Section D of this
preamble except that location standards
are not analyzed.
Costs, economic impacts, and risk
estimates (including resource damage)
are.presented in this section for the
proposal and the three regulatory
alternatives; primary emphasis will be
on results for the proposed rule.
3. Cost Analysis
. a. Methodology. The Agency
developed an engineering cost model to
estimate total costs for an MSWLF
under a variety of technical and
regulatory scenarios. This model
estimates the cost to design, construct,
operate, close, and provide post-closure
care for an MSWLF. The model allows
for user-specified input variables such
as waste throughput, operating life, type
and depth of fill operation, number of =
phases of construction, containment and
cover systems, waste density,
environmental monitoring and control,
post-closure care, and a variety of unit
costs and fees for construction and
operation of the facility. Based on these
inputs, the model calculates the
necessary landfill dimensions (e.g.,
active area), capital costs, operating and
maintenance costs, closure costs, arid
post-closure costs of the facility. In
addition, the model assigns these costs
to specific years of the operating life and
post-closure care and then calcualtes a
present value (hi 1986 dollars) based on
a 3 percent real discount rate. The
model can estimate costs for any landfill
size between 10 and 1,500 TPD. National
costs for a given option then are
calcualted using these unit costs and a
size distribution of MSWLFs.
EPA selected a limited number of
generic user inputs to the model and
held these constant across the
regulatory options so that cost
differences in the environmental
controls would be highlighted. EPA
selected seven model facility sizes for
modeling costs. Preliminary results form
the Subtitle D Solid Waste (Municipal)
Landfill Survey (referred to here as the
Facility Survey) were used to assign a
frequency distribution to each size
category. The seven model sizes used
(and the assigned frequency of
MSWLFs) are: 10 TPD (51.4 percent), 25
TPD (16.9 percent), 75 TPD (12.7
percent), 175 TPD (7.1 percent), 375 TPD
(6.5 percent), 750 TPD (3.2 percent), and
1,500 TPD (2.3 percent). (Although the
1,500 TPD category includes only 2.3
percent of all MSWLFs, these facilities
• handle 36.5 percent of all waste.) EPA
assumed for the cost analysis that all
MSWLFs opertate in one phase and use
a cut-and-fill method of operation.
EPA estimated corrective action costs
separately using the failure and release
component of the risk model (described
in Section X1.A.4 of this section). EPA's
approach to estimating corrective action
costs partially reflects the flexibility of
this requirement in the proposed rule.
EPA estimated costs based on aggessive
cleanup of new contamination and
either aggressive or passive cleanup of
existing plumes. This approach to
estimating corrective action costs was
used for all regulatory alternatives in
addition to the proposed rule.
For new contamination, EPA modeled
the effects of ground-water recovery
wells as the selected corrective action
technology. The recovery wells are
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33335
, assumed to be installed one year after
the corrective action has been triggered.
For existing contamination, EPA
estimated corrective action costs for two
types of responses. The first response
consists of active restoration of the
plume using ground-water recovery.
wells (i.e.i the approach modeled for
new facilities). EPA assumed that this
approach will be utilized for larger
plume sizes as the most effective
remedial measure. To partially account
for the flexibility provided by the
, corrective action requirement in terms of
the timing and response to contaminant
plumes, the second response represents
a passive approach for smaller plumes.
EPA assumed that this passive approach
would consist of providing an
alternative water supply to affected user
of the gound water. EPA recongizes that
alternative technologies or remedies
may be employed for cleanup of affected
ground water. Corrective action costs
were added to the design and operating
costs to derive total costs for a given
regulatory option.
To obtain incremental regulatory
costs, EPA first characterized MSWLF
baseline practices. Baseline practices
are those design and operating practices
that exist prior to the imposition of the
requirements in today's proposed rule.
EPA characterized baseline conditions
using preliminary results from the
Facility Survey and results from the
State Census. For purposes of this
analysis (including the economic impact
and risk analyses discussed later), EPA
characterized the baseline facility as an
unlined landfill with a vegetative cover
at closure, no environmental monitoring,
no post-closure care, and no corrective
action. However, as described below,
EPA adjusted compliance costs to
account for existing State requirements
with respect to liners, leachate
collection systems, and ground-water
monitoring well requirements. The
MSWLF population is extremely diverse
in terms of its technical characteristics
(e.g., presence of environmental
controls, design capacity, remaining
life), which is due in part to a broad
range of State requirements that vary in
..both scope and detail. EPA reviewed the
State requirements to identify those
States that require containment (i.e.,
; liners, leachate collection systems) and
ground-water monitoring well
requirements that would likely satisfy
the conditions in today's proposed rule.
EPA identified 22 States with similar
, liner and LCS requirements and 24
.States that have similar ground-water
monitoring well requirements. EPA
adjusted the regulatory compliance cost
estimates for facilities in these States.
The adjustment for State liner and
leachate collection system requirements
was made only for analyzing the costs
of the proposed rule; the costs for all
regulatory options accounted for the
existence of State requirements for
ground-water monitoring wells. To the
extent that other existing State
requirements are similar to those in
today's proposed rule, the estimated
compliance costs will be overstated
Although EPA adjusted the national
compliance cost estimates to reflect
these State requirements, the risk and
resource damage estimates were hot
adjusted to reflect the presence of
containment systems in the baseline.
The benefits of the regulatory options in
protecting ground water as a drinking
water source (presented in this section
and in the RIA) will likely be overstated
by not incorporating the presence of
these State requirements; however, EPA
has not analyzed the benefits of the
regulatory options in reducing risk from
other routes of exposure (e.g., surface -
water, subsurface gas, risks to the
ecosystem). Therefore, the net benefits
of the rule will likely be understated.
The Agency estimated compliance
costs for each Facility Survey
respondent. EPA assigned each
respondent a weighting factor that
represents the frequency of that type of
iacihty in the total national regulated
population of 6,034 active MSWLFs. The
weighting factors were used to scale
respondent facility costs up to national
compliance costs for the regulatory
options. EPA estimated compliance
costs separately for new and existing
requirements. In addition, EPA
combined the new and existing MSWLF
estimates to produce a compliance cost
figure that represents an average cost
for existing units and their new
replacement landfills. New landfills are .
assumed to be perpetually replaced for
this combined estimate.
For new MSWLFs, all regulatory costs
are assumed to apply from the time'
construction begins. A new landfill is
assumed to operate for 20 years and
compliance costs (in present value
terms) are annualized over this time
period. For those facilities with longer
operating lives (approximately 60
percent of all MSWLFs as reported in
the Facility Survey), the annualized
costs will be lower due to an increased
amortization period for capital costs.
For existing MSWLFs, the regulatory
costs are applied over the remaining
operating life as reported in the Facility
Survey. (Existing MSWLFs that were
reported in the Facility Survey to be
closing before the effective date of the
proposed rule were not assigned
existing requirement costs. These
landfills were assumed to be replaced
with new facilities to which appropriate
requirements were applied.) EPA
annualized the regulatory costs for an
existing MSWLF over the remaining life
of the facility, EPA assumed that
revenues are generated to pay for
regulatory costs during the operating
life. Although this is. likely to be true for
private landfills, publicly owned
facilities may have the option of passing
on the costs (for facilities with short
remaining lives) to future facilities and
thus reduce the cost impact. Existing
landfill costs will tend to be overstated
for these facilities that amortize the
costs over a period that extends past the
reported .remaining life.
To develop a combined estimate of
average annualized compliance costs for
the regulatory options, costs for existing
units plus their new replacement
landfills have been discounted to one
present value that spans the existing
landfill's remaining life plus the ongoing
life of a new landfill that is replaced
every 21) years. (Replacement of all
existing; MSWLFs with new MSWLFs
does not account for the current trend
away from siting new landfills;
moreover, it is unlikely that each of the
existing 6,034 MSWLFs will have a
replacement landfill in perpetuity.
Regionalization, recycling, shifts to
resources recovery, and better siting of
landfills in "good" locations will result
in fewer new MSWLFs than estimated
in this analysis^ EPA has not
incorporated these factors into the
analysis because they involve
simulating site-specific local decisions
that are difficult to analyze. EPA's costs
will tend! to be overstated by not
including these factors.) EPA assumed
that the new MSWLF would be built at
the same: location such that the required
designs remain the same. EPA then
annualized this present value as a .
perpetuity to obtain an annualized
combined compliance cost estimate for
a given regulatory option. Although this
figure does not represent the actual cash
flow (i.e.;j for capital outlays) that would
likely result from regulation, it does
represent a level annual payment as if
the facility operator had borrowed funds
to pay thu capital costs. This annualized
combined cost estimate is used in the
economic impact analysis of the
regulatory options. Compliance costs
specific to new and existing •
requirements are presented in detail in
the RIA; however, costs (and economic
impacts) presented in this section of the
preamble only reflect the combined
estimates,; .
-------
For the proposed rule, EPA estimated
the effect of the design goal on new
MSWLFs by analyzing the baseline risks
[a detailed discussion of the risk
methodology is presented later in this
section). For the purposes of this
analysis, EPA assumes all MSWLFs
would comply with a design goal of 10~s
from the allowable protective range of
10"* to 10"7. Actual costs (and benefits)
of the proposed rule will vary depending
on the state-selected design goal.
Landfills with an average most exposed
individual rf«k below 1 X 10~B in the
baseline (i.e., unlined with a vegetative
cover) were excluded from any further
design requirements. EPA estimated that
these facilities would not trigger
corrective action since risks at these
units would never exceed the 1 X 10~5
trigger level used for this regulatory
analysis.
Those new facilities that exceeded a
1X10~S risk level in the baseline then
were modeled with a synthetic cover.
EPA assigned these facilities a synthetic
cover if risks were reduced to below
1X10~*. For the subset of facilities that
Btill exceeded the design goal, EPA
assigned a synthetic containment
system with leachate collection and a
synthetic cover. Those landfills that still
exceeded the risk threshold with this
more stringent design would trigger
corrective action. EPA selected these
designs for the purpose of conducting
this analysis. These designs are neither
specifically required by the proposed
rule nor do they represent the only
designs that could satisfy the
performance standard; however, the
chosen designs do represent features
that would be applicable and effective
in a wide range of environmental
settings.
EPA only assigned liners and leachate
collection systems to new units: no
lateral expansion was assumed to occur
at existing facilities so that covers
would be the only applicable design
requirement to meet the performance
standard. Under the proposed rule,
existing units must have a cover that
prevents infiltration. In the RIA, EPA
assigned a vegetative cover if baseline
risks were less than 1 X lO"5; for the
subset of facilities that exceeded this
baseline risk level, EPA assigned a
synthetic cover. Other cover systems
besides these two modeled in the RIA
could be used to comply with the
performance standard. EPAmoedled the
proposed rule at one design goal (1 X
10"*) and two POCs: The waste unit
managemcmt boundary (modeled as the
10-meter POC) and the maximum
allowed alternative boundary of 150-
meters (the 150-meter POC).
For compliance at the 10-meter POG,
EPA estimated that 61 percent of the
MSWLFs would require an unlined unit
with a vegetative cover design, 11
percent an unlined unit with a synthetic
cover, and the remaining 28 percent a
synthetic liner with leachate collection
and a synthetic cover. At the 150-meter
POC, EPA estimated the resulting
percentages as 79, 9, and 13 percent,
respectively. In addition to the design
requirements necessary to achieve the
design goal, EPA assigned compliance
costs to both new and existing units for
the general facility standards and other
requirements. These requirements
include: Developing procedures for
excluding hazardous waste from the
landfill, monitoring for methane in the
subsurface and in structures, run-on and
run-off controls, developing and
implementing a closure plan, and
ground-water monitoring. Although EPA
modeled an extended post-closure care
period (including cover and slope
maintenance, cover inspection, and
ground-water monitoring) the proposal
requires a two-phased post-closure care
period at a minimum of 30 years. In
addition, the ground-water monitoring
parameters modeled in the RIA differ
from those under the proposed rule. EPA
did not estimate costs for financial
responsibility requirements. Detailed
discussion on how EPA estimated
compliance costs for these requirements
is provided in the RIA.
Under the proposed rule, States may
take into account the resource value of
ground-water supplies when
determining ground-water monitoring
requirements. EPA assumed in this cost
analysis that ground-water monitoring
systems include one upgradient (three-
well) cluster and a number of
downgradient clusters that vary with the
length of the downgradient boundary
(e.g., four clusters for a 10 TPD MSWLF,
20 clusters for a 1,500 TPD facility). EPA
assumed that ground-water monitoring
would be conducted on a semiannual
basis. For existing MSWLFs, the ground-
water monitoring requirements were
phased in over five years. Under the
proposed rule, States may vary the
number of wells, frequency of
monitoring, and timing of ground-water
monitoring implementation. To the
extent that actual ground-water
monitoring requirements specified by
the States differ from what was modeled
in this analysis, the actual compliance
costs will vary from those estimated by
EPA. .
Alternative 1 imposes uniform
standards on all MSWLFs. Existing unit
requirements are the same as for new
units except that the containment and
LCS requirements Were not assigned.
Ground-water monitoring is not phased
in, and the Phase II list of parameters
under the proposed rule is used as the
list of constituents for which all units
must monitor. EPA assigned a composite
cover to all new and existing units
(similar to that described in 40 CFR
264.310) and a double composite
containment system with two LCSs
(similar to that described in 40 CFR
264.301) to all new units. EPA assumed
that clay for the cover and containment
systems was obtained off site unless the
survey respondent reported that clay or
sandy clay was available at the facility.
Alternative 2 represents a categorical
approach, based on location, to
determine the necessary containment
and cover requirements. This categorical
approach is described in Section IX.D of
this preamble/Landfills are assigned
designs based on the local climate and
hydrological factors that control the
potential for leachate contamination
(i.e., the migration potential at the site).
To estimate the effects of Alternative
2, EPA used respondent-supplied data
on location, primary soil type, saturated
permeability, and porosity to determine
the distribution of MSWLFs across the
four location categories. EPA used the
location data to assign an annual
precipitation figure obtained from the
nearest National Weather Station. The
annual cutoff value for high and low
precipitation under Alternative 2 is 40
inches. To determine the split between
short and long time-of-travel. the
Agency used either a saturated time-of-
travel equation or an alternative
equation (a wetting-front approach)
depending on whether the site was
reported to be in a saturated
environment. The cutoff for short versus
long time-of-travel is the greater the
active life or 20 years. Using this
approach, the Agency estimates that the
percentages of all MSWLFs in location
Categories I, H, HI, and IV are 29.2
percent, 5.8 percent, 37.8 percent, and
27.2 percent, respectively.
Cover and containment requirements,
which are performance-based for
Alternative 2, were assessed for each
survey respondent as described below.
Alternative 2 requires facilities to use a
water-balance method to select the
proper cover that will minimize
infiltration through the cover at any time
in the future. There are several
measures that the facility owner or
operator could undertake to meet this
performance standard if the vegetative
coyer by itself is not sufficient. For
example, in order to minimize
infiltration, the owner or operator could
vary the type of vegetation to increase
-------
the evapotranspiration, vary the slope of
the coyer to increase run-off, use heavier
soils from off site, or install a clay or
synthetic layer with a drainage
collection system beneath the vegetative
cover. These decisions involve site-
specific factors and are difficult to
analyze. Thus, EPA limited the options
tor cover type to either vegetative or
synthetic. EPA assumed that MSWLFs
with positive annual net precipitation
(precipitation minus potential
evapotranspiration) will use a synthetic
cover. EPA assumed that landfills with
zero or negative net precipitation use
the same cover design that was
simulated for the baseline, except that
the cost includes additional fees for
quality assurance. (Potential
evapotranspiraticawas determined
. using the Thornwaithe-Mather
equation.) Using this approach, EPA
estimates that 67 percent of all MSWLFs
have positive net precipitation and thus
are assigned synthetic covers; the
remaining 33 percent are assumed to
achieve the performance standard with
vegetative covers. EPA applied costs for
these covers to both new and existing
units. e
Alternative 2 assumes that all
MSWLFs in location Categories II and
IV (34 percent of all facilities) must have
a leachate collection system; units in
location Categories L and III must collect
leachate if more than one foot of
leachate is generated over the active
Me. The Agency determined the
leachate generation for Facility Survey
respondents in Categories I and ffl using
the approach described in EPA
publication 530/SW-168. The Agency
estimates that 63 percent of the landfills
m these two categories (or 41 percent of
all facilities) would need an LCS. Thus
across all MSWLFs. the Agency
estimates that 75 percent will be
required to have an LCS.
Under Alternative 2, the need for a
containment system for MSWLFs in
location Categories I and H only is
related to the need for an LCS since they,
already have a long time-of-travel. A
containment system is necessary if the
native soil does not have a sufficiently
low permeability to allow the LCS to
™?ctj°n Properly. EPA assumed that
MSWLFs in tiiese categories that need
an LCS and that reported clay as their
primary natural soil type in the Facility
Survey do not need a liner [estimated as
10 percent of all MSWLFs). EPA
assigned the remaining units (four
percent of all facilities) that need an
«f5*1 *esre Categories a synthetic liner
so that the LCS would perform
efficiently;
•—-
MSWLFs in Categories HI and IV that
aUfadUtS (?sfimated as 61 Percent <
ail tacihties) also must have a
containment system that will increase
the time of trairoi * :„,._ ., ""-""we
s, to
— i-«~«v»i*i. \ji a.li ivXOVV
jgories I and HI. Those
raat are in Category I (20
of all MSWLFs) have a long
i7^; ~v A 'aud mus do not need a
hner. For those in Category HI (five
percent of all MSWLFs), EPA assigned a
two-foot flj!?k. clay liner that should
provide sufficient delay to meet the
performance standard. Moreover, even
if clay had to be brought from off site, a
clay hner is less expensive than
synthetic given that a synthetic liner
would also require installation of a
leachate collection system.
Although these assignments of
designs to meet the performance
standards for Alternative 2 do not
reflect the inherent flexibility of
performance requirements, EPA believes
that they do provide an indication of
now these standards would be met. The
general facility standard requirements
(and resulting compliance costs) for
Alternative 2 are identical to those
analyzed for the proposed rule.
Alternative 3 consists of uniform
criteria applied to both new and existing
landfills. This regulatory alternative is
similar to the statutory minimum
mandated under HSWA and includes
analysis of ground-water monitoring
(throughout an extended post-closure
care period) and corrective action
requirements; however, EPA has not
incorporated any location standards
into the analysis for this alternative.
Alternative 3 is the only regulatory
option that does not include general
facihty standards. EPA assumed that
ground-water monitoring would begin
on the effective date of the regulation. A
more detailed discussion of the cost
analysis for each of the regulatory
options is included in the RIA.
b. Cost Results. The Agency estimates
that the proposed rule will-result in an
annualized cost of approximately $880,0
million at the 10-meter POC and $6914
million at the 150-meter POC. Thus
based on the $100 million annual cost
tnresnold established in E.0.12291
today's proposal is a "major" regulation.
Table 3 shows the size distribution of
MbWLFs across the seven facility, sizes
modeled in the cost analysis, as well as
the annualized cost of the proposed rule
for each facility size. EPA estffi
the smallest size category (i.e., 10 Tf.
MSWuTT* f°r 51'3 percent °fa>
MSWLFs, only accounts for 6-percent
and 7-percent of the total cost of the
proposed rujeunder the 10-meter and
150-meter POCs, respectively. The two
ni es moee Pro
,5001TD) account for only 5.7 percent
f all MSWLFs, but 35 percent to 33
percent of the total costunder Sr
TABLE 3.-ANNUALI2ED COMBINED COST
BY SIZE. PROPOSED RULE
tDoliars in millions]
$52.3
85.S
134.0
128.5
148.7
137.3
193.4
$47.3
72.2
107.6
95.6
130.3
93.4
145.0
'Does not adddus to rounding.
' approximately
(52 5 percent for ihe y
c) of all MSWLFs willincur an
tal cost increase of less than
ncrease o ess tan
«n Pe- tan: 49-2 Percent (45 percent for
150-metei;poC) face an increase
between $10 and $25 per ton, and 4.8
percent (|.4 percent for 150-meter POC)
will incut; a compliance cost between
nTvr^i? $5° per ton- Under &e 150-meter
n Sn estimates that 1.2 percent of
all MSWIJs will incur cost increases of
greater than 50 percent per ton due to
expensive; corrective actions that are
triggered.]
Table 4 shows the total annualized
combinedicosts for today's proposed
rule and the three regulatory
alternatives. The annualized costs,
including corrective action, range from
$419 million for Alternative 3 up to
$3,341 million for Alternative 1. The
costs for tiie proposed rule, under either
POC, falls near the lower end of the
range. Corrective action is triggered
under all the regulatory options and
represents from 2-percent (under .
Alternative 1) to 72 percent (under
Alternative 3). of the total costs.
Corrective action represents 11 percent
and 19 percent of the total cost of the
proposed rule for the m-meter and 150-
meter POCs, respectively. The relative
costs across options araaffected by the
stringency of the requirements only,
-------
since the facility size distribution and
tra^eofre^ai^nvesarB^nst
sts across the options reflects
ive nature of a
n costs across the options reec
the reactive or preventive nature of a
given regulatory scenario. Alternate 3,
representing a reactive approach to
releases, has the largest percentage ^of
corrective action costs to total costs
among the regulatory options.
TABLE 4.— TOTAL ANNUAUZED COSTS
FOR REGULATORY SCENARIOS
tDoters In mStopsl
propottl:
10-metorPOC
ISO-mater POC
S782.2
562,0
3.268.6
1,336,9
117.1
$880.0
691.0
3,341.0
1.426.9
419.4
,,
Table 5 presents the incremental cost
per ton forPthe regulatory scenarios. The
median, minimum, andmax^um
estimates are shown for each option.
TABLE 5.-ANNUAUZED INCREMENTAL
COSTS PER TON BY OPTION
- • •
regulatory costs was assessed. The -
second phase was an assessment of tne
ability of citizens to pay for the
increased compliance costs.
The first phase, an assessment ot -
impacts on local governments, consisted
of two components. First, the cost of
compliancewas reviewed relative to the
overall financial capability o tiie
community. Financial capabihty (or
rSancial health) was determined from
the "1982 Census of Governments and
the "1983 County and City Data Book.
These data bases represent the most
recent available and complete
information on local government
finances (as government censuses are
conducted every, five years). As
described in the RIA, ^Agency
assessed financial capability by
developing a composite Bcore/n* scme
categorizes communities nnanciai
capabilities as weak, average, or strong.
The financial capability score of a
community will not change significantly
due to compliance costs from the
unposition of the proposed rule because
m£iy of the indicators used to develop
^o T,nt Hirentlv affected by
„____—-_ _
MSWLF costs by increasing taxes,
reducing other services, increasing debt
levels, or turning to private contractors.
EPA has assessed the absolute impact n
terms of total cost per household (CPHJ.
EPA has measured the relative impact
various analyses produce an overall
indication of the significance of
municipal economic impacts for specinc
regulatory options.
For this analysis, the Agency selected
threshold levels to identify high impacts
4 Economic Impact Analysis
a. Methodology. Preliminary results
from the Facility Survey mdicate that 80
pSnt of all MSWLFs are owned by
local governments (e.g., counties, cities,
owns, villages!. These governments will
incur the initial costs and impacts
attributable to the revised Criteria;
however, ultimately the goyernments
will likely pass on the regulatory costs
to their citizens and to other
governments that also may use the
landfill. The compliance costs will be
passed on in the form of increased taxes
or fees or decreased services of other
types if the community is operating
under tight budgetary constraints, inus,
local citizens (the households that use
the landfills to dispose of their wastesj
will eventually pay the increased costs
a^ffiffissssas
governmental entities to pay for the
many of the indicators useoi.™™
the score are not directly affected by
increased operating expenditures. In
addition, it would not be appropriate to
presuppose the reaction of a community
to higher landfill costs. Some
communities will increase taxes while
others will reallocate available funds to
meet the regulatory burden. In the area
of debt impact, it also is not clear how a
given project will be financed. Many
communities will use pay-as-you-go
financing as they always have others
vrillmcur debt, and the remahider will
turn to private contractors who will
raise their own capital.
The development and categorization
of the composite score is described in
detail in the KLA. The economic impact
analysis results presented in this section
of the Preamble focus on comparisons of
compliance costs to government and
demographic indicators as described
below. " ,
The second component of the
community impact analysis consisted of
calculating compliance costs as a
percentage of total current community
Lpenditures (CPE) and comparmg this
ratio to a threshold level. The CPE
indicator serves as a convenient
summary of the local government s
ability to pay.
The second phase of the economic
impact analysis consisted^ comparing
compliance costs to the ability of
citizens to pay. This comparison is
appropriate because, ultimately, the
burden will fall on the citizens,
regardless of whetiier the local
government pays for the increased
CPE, preliminary results from the
Facility Survey indicate that municipal
solid waste disposal costs average
approximately 0.5 percent of •
communities'total expenditures. In
comparison to other municipal services
costs at this level represent a very small
obligation. Data from the "1982 Census
of Governments" indicate that the
average community spends 36 percent of
its totll budget on education, 5-percent
of its total budget for police protection,
3-percent for sewage disposal, 2-percent
for fire protection, and 1-percent for
sanitation services other than sewage
(including solid waste collection and
disposal and street cleaning). Based on
these data, the Agency established a
threshold for identifying high impacts as
one percent of compliance costs relative
to total community expenditures.^ ,
The Agency used two threshold levels
to assess the severity of costs per
household. An incremental regulatory
cost of $100 per household per year was ,
selected as a threshold for moderate
Impacts. Although this cost represents a
large percentage increase in many
households' disposal costs, it represents
i_i: u, «,rr,Qll nhsnlute charge. An
households' disposal uusio, ""*"-•-----
a relatively small absolute charge. An
annual threshold of $220 per household
was used to identify severe impacts,
This threshold level is equivalent to one
percent of the median household income
of all the communities in the country
according to the "1983 City and County
Data Book." ' ,
The Agency has previously selected a
threshold level for costs as a percentage
of median household income under the
Construction Grants Program. The
criteria ranged from one percent ot
median household income for low-
income communities to 1.75 percent of
MHI for high-income communities. The
Economic Impact Results. Table 6
shows the percentage of communities
-------
33389
under each regulatory scenario that
have compliance costs exceeding one
percent of total current community
expenditures, the percentage of all
people that reside in these communities,
and the maximum CPE under each
option.
TABLE 6.—COSTS AS PERCENTAGE OF
EXPENDITURES
[Regulatory Options]
Regulatory
scenario
Proposal: 10-meter
POC
Proposal: 150-
meter POC
Alternative 1
Alternative 2
Alternative 3
Percent
of
communi-
ties with
CPE>1%
16
11
68
33
10
Percent
of people
with
CPE>1%
7
4
34
-12
3
Maxi-
mum
CPE
(per-
cent)
5.3
14.0
ft o
8.6
EPA estimates that greater than one-
half of all communities under
Alternative 1 have CPE exceeding one
percent. Under Alternative 2, 33 percent
of all governmental entities have CPEs
that fall in this category. The percentage
of municipalities with costs above 1-;
percent of current expenditures under
the proposal is much lower: 16 percent.
and 11 percent, given the 10-meter POC
and 150-meter POC, respectively.
Because most of these severely-
impacted communities are small, the
percentage of the total U.S. population
that resides in these communities is
much smaller than the percentage of
communities affected fas shown in
Table 6).
Several factors will tend to mitigate
.the actual impact of the alternatives on
communities with high CPE. One
important factor is the relatively small
proportion of the municipal budget that
is usually devoted to municipal solid
waste disposal. Although CPE greater
than 1-percent indicates that municipal
solid waste disposal expenditures may
double in many communities, after
regulation these expenditures will still
represent less than 2-percent of the total
municipal budget in most'communities.
Although it may be difficult for
communities to pope with large
percentage increases in municipal solid
waste disposal costs in the short run,
once the initial adjustment is made,
these costs should be easier for
communities to absorb because they
comprise a very small portion of
communities' total budgets.
Table 7 shows the average CPH,
across the entire nation, maximum CPH,
and percentage of all communities with
costs per household exceeding $100 per
year (the moderate impact level). The
Agency estimates that average
incremental CPH across the entire
nation ranges from $5 under Alternative
3 to $40 under Alternative 1. For the
proposal, EPA estimates that the
average CPH is $11 at the 10-meter POC
and $8 at 150-meter POC.
TABLE 7.—AVERAGE COST PER
HOUSEHOLD PER YEAR
(Regulatory Options)
Regulatory scenario
Proposal: 10-rneter POC...
Proposal: 150-meter
POC
Alternative 1
Alternative 2 .........
Alternative 3....
Aver-
CPH
$11
8
40
17
5
Percent
of
commu-
nities
with
CPH<
$100
(per-
cent)
0.2
2.1
23.5
0.1
0.2
Maxi-
mum
CPH
$119
253
qqc
OO3
160
17ft
I/O
EPA has selected, for this analysis, a
threshold level for severe impacts on
households of $220 per year. The.
Agency estimates that this threshold is
exceeded under Alternative 1 and at the
150-meter POC for the proposal, but only
by fewer than 0.1 percent of all
communities in both cases. When the
$100 per year threshold is considered,
EPA estimates that, for all regulatory
options except Alternative 1, the
TABLE 8.—NUMBER OF COMMUNITIES AND LANDFILLS BY TYPE OF OWNER
percentage of communities that exceed
this level is low (i.e., less than 3-
percent). However, under Alternative 1,
EPA estimates that 23.5 percent of all
communities experience increases in
CPH of greater than $100 per year.
Cosit per household as a percentage of
MHI is relatively low across all of the
regulatory options. The Agency
estimates that the 1-percent threshold
level is exceeded under the proposal at
the 150-meter POC and under
Alternative 1. Even under these
regulatory options, fewer than 2-percent
of all .households fall into the high
impact-category (0.1 percent exceed the
threshold at the 150-meter POC and 1.1
percent fer Alternative 1). EPA
estimates that the maximum CPMHI is
1.3 pel-cent under the proposal at the
150-meter POC and 1.7 percent under '
Alternative 1.
Impiacts on" households also, depend
on who owns the landfill that serves
those households. Table 8 indicates the
number of communities and landfills by
each major ownership category—
county, city, village or town, private,
and other. (The other category covers
landfills owned by nonlocal
governments including special districts,
States, and the Federal government.)
The distribution of communities by
ownership type looks somewhat
different than the distribution of
landfills by ownership type because
county-owned and private landfills tend
to serve a larger number of communities
than city or town landfills. The table
indicates that communities served by
village' or town landfills have much
higher CPH than average. These
landfills tend to serve only one or two
communities and are, commonly very
small, ihus the CPH is higher.
Communities served by private landfills
tend to have lower than average CPH.
These landfills usually serve many
communities and, on average, are larger
than publicly owned landfiSs. Smaller
communities could reduce the regulatory
burden by participating in larger
regional landfills.
[Average Community CPH for Proposed Rule]
Owner
County „ ..
City
Village or Town
Private
Other
Total
Communities
Number
10,618
6,622
2,115
8,556
1,087
28.993 »
"Totals may not add to 100 percent because of rounding.
" Data are missing.for 10 landfills in 19 communities.
Percent
37
23
7
3D
4'
100 *
Landfills
Number
1,760
1,743
1,182
912
427
Percent
29
29
20
15
8
100"
Average
number of
communities
per landfill
,i 6.0
3.8
!' 1.8
i 9.4
'! 2.6
j. 4.8
Average Community CPH
Fed POC
$18
16
34
10
15
$16
State POC :
$13
15
31
10
15
$14
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33390
Federal Register /Vol. 53, No; 168, Tuesday,
As stated previously, the costs used in
the economic impact analysis represent
a reasonable upper-bound estimate.
Several opportunities exist for
communities to reduce the regulatory
burden: Reglonalization to share the
economies of scale at larger landfills,
shifts to resource recovery facilities,
increases in the rate of recycling to
reduce the waste volume for disposal,
and better siting of new MSWLFs in
"good" locations. (As explained above,
EPA has not incorporated these
mitigating factors into the analysis
because they involve site-specific local
decisions that are difficult to predict.)
5, Risk Assessment
o. Methodology. The Subtitle D
MSWLF universe consists of a diverse
group of facilities that occur in a wide
variety of environmental settings.
Hundreds of factors affect the nature,
extent, and severity of environmental
impacts from these facilities. To identify
and evaluate some of the most
important factors, EPA developed the
Subtitle D Disk Model. This model
couples information from case studies
and other sources with a series of
mathematical formulations of
engineering, physiochemical, hydrologic,
toxicologlc, and socioeconomic
processes that govern impacts to
provide a framework that allows
evaluation of regulatory options.
Although the Subtitle D Risk Model
has been neither peer reviewed nor
verified, EPA has used it in its
preliminary form to help analyze: (1)
Problems associated with Subtitle D
facilities under the current set of Criteria
(i.e.. baseline), (2) estimates of the level
of risk reduction available from
preventive measures (liners, leachate
collection systems and covers), and (3)
remedial measures (corrective action)
under various regulatory options. For
each regulatory alternative, risk and
resource damage has been modeled in
hundreds of scenarios that represent
unique combinations of landfill size and
design, environmental setting, and
exposure distance. EPA has estimated
the frequency for which each scenario
occurs in the total population of
MSWLFs and weighted the results for
each scenario reflect the frequency of
occurrence. The following is an
overview of the risk model.
(1) The Subtitle D Risk Model. The
Subtitle D Risk Model provides: (1) An
analytic framework for estimating
human health risk reduction and other
benefits of regulatory options, (2) a
direct link between estimates of benefits
and costs of regulations, and (3)
scenarios that contain different
combinations of design, waste,
environment, and response. The model
builds directly on the Subtitle C Liner
Location Risk and Cost Analysis Model
(Ref. 20), and has adopted many of its
basic characteristics. It is a dynamic
model For this analysis, EPA simulated
100 years of leachate release and 200 .
years of gound-water transport for each
year's release. Environmental fate and
transport and dose-response
relationships are modeled as
deterministic processes, while
containment system failure and some
hydrologic events are considered
stochastic phenomena. The model only
assesses effects on ground water as the
environmental medium of concern:
ecosystem risks and subsurface gas and
surface water pathways (which also
would contribute to risk) are not
analyzed. Some parameters can be
varied over a wide range; for others, the
user selects from specified, generic
values.
The model includes a series of
submodels that simulate pollutant
release (liner failure and leachate
quality submodels), fate and transport
(unsaturated zone and saturated zone
transport submodels), exposure, impacts
(dose-response and resource damage
submodels), and corrective action.
Following are brief summaries of each
of these submodels.
fa} Pollutant Release. The Agency
used Monte Carlo simulation in the
failure/release submodel to estimate the
probability and time of failure (denned
as release to the unsaturated zone) for
MSWLFs and to estimate the quantity of
leachate released. The submodel uses a
fault tree structure that traces each
possible failure event from all possible
combinations of basic events (e.g., liner
failure, infiltration of liquid) that could'
combine to cause failure. Each of these
basic events is assumed to occur at
random, following specified probability
distributions. The model provides
distributions of the year of failure and
the release rate. EPA used the model to
simulate the performance of several
combinations of containment and cover
systems hi eight environmental settings.
The leachate quality submodel
simulates the concentrations of chemical
constituents in leachate released from
the MSWLF between years \ and 100.
Given differences in the leaching -
behavior of constituents, the submodel
utilizes three different modeling
approaches to simulate the
concentrations of inorganics,
biodegradable organic?, and synthetic
organics in leachate. The submodel .
applies the appropriate algorithm to
calculate the concentration of each"
leachate constituent for each year. The
concentration then is combined with the
release volume calculated by the
failure/release submodel to calculate
the mass flux of the constituent across
the landfill/subgrade boundary.
One representative leachate,
consisting of eight constituents of
concern (COG), was simulated. This
leachate is intended to represent typical
leachates generated from co-disposal of
municipal solid waste, nonhazardous
industrial waste, and VSQG hazardous
waste. EPA selected the COG based on
analyzing limited leachate data from
only 44 operating MSWLFs. The COG
were selected based on potential for
causing human health risk or resource
damage given their observed median
concentrations in municipal solid waste
leachate, toxicity to humans, regulatory
limits under SDWA taste, and odor
thresholds, and mobility andjsersistence
hi the subsurface environment. The eight
COG and the effect of concern for each
are given below:
Constituent
Vinyl chloride.., ....
Arsenic.....
Iron '•
1,1,2,2,-'
tetrachloroethane.
Dichloromethane
Antimony
Carbon tetrachloride.
Phenol
, Criterion effect
Human health risk (cancer).
Human health risk (cancer).
Resource damage (taste and
odor).
Human health risk (cancer).
Human health risk (cancer),
Human health risk (system-
ic).
Human health risk (cancer).
Rsource damage (taste and
odor).
(b) Fate and Transport, Subsurface
transport modeling addresses transport
through both the unsaturated zone and
the saturated zone. The Subtitle D Risk
Model uses the McWhorter-Nelson
wetting front equation to calculate the >
delay between the time of failure and
the time that contaminants reach an
underlying aquifer. The mass that
breaks through the unsaturated zone
then disperses through the ground
water. Using an adaptation of the
Random-Walk Solute Transport Model
(Ref. 25) developed by Prickett, Naymik,
and Londquist, the saturated zone model
simulates downgradient ground-water
concentrations over time.
To model the transport of
constituents, EPA developed eight
environmental settings consisting of four
net infiltration regimes (0.25-inch, 1-inch,
-------
10-inch, and 20-inch) and two categories
of ground-water depths (deep and
shallow). These two parameters are
important in affecting the release rate of
leachate to the unsaturated zone and
. ultimately the aquifer. Net infiltration
represents the amount of water that can
enter the landfill as a result of
precipitation. Ground-water table depth
represents the potential for pollutant
attenuation and degradation to occur in
the unsaturated zone. In addition, for
facilities that are seasonally inundated
with ground water, the inundation depth
determines the rate at which ground
- water can flow through the waste.
EPA performed a statistical analysis
of USGS data for each infiltration
category to determine the mean depth to
ground water and the average annual
ground-water fluctuation, Shallow and
deep water table depths are represented
by the 50th and 90th percentiles,
respectively.
For transport through the saturated
zone, EPA developed 11 generic ground-
water, flow fields to represent the range
of hydrogeologic conditions in the
United States. The flow fields are based
on data collected from ground-water
supply reports for each of the USGS
regions.The flow fields vary in terms of
aquifer configuration, materials, and
flow velocity. Five of the flow fields are
single-layer aquifer systems, two
contain two adjacent aquifers, three
consist of an aquifer overlaid with a •
nonaquifer, and one contains two
aquifers separated by a nonaquifer.
EPA assigned each surveyed landfill
to a net infiltration region based on its
precipitation level (obtained from the
nearest National Weather Station) and
other climatic data. Each of these
MSWLFs also was assigned a DRASTIC
(Kef. 39) setting to select appropriate
ground-water table depths and flow
lields. These assignments were used to
develop a frequency distribution for
each environmental setting. EPA used
these frequency weights to scale up the
risk model results to obtain national
estimates. .
(c) Exposure Distance and
Populations. EPA selected seven well
distances for modeling risk: 10 meters,
60 meters, 200 meters, 400 meters, 600
meters, 1,000 meters, and 1,500 meters.
Preliminary results from the Facility
Survey were used to develop a
frequency distribution of distance from
the MSWLF to the closest drinking
water well at each site. This distribution
(i.e., distance to closest well) was used
to estimate risk to the maximum
exposed individual (MEI).
Approximately 54 percent of the
MSWLFs were reported to have no
downgradieht drinking water well
within one mile of the facility. For the
other 46 percent of MSWLFs: 12.8
percent reported wells within 300
meters, 22.5 percent reported wells
within 500 meters, and 40.3 percent
reported wells within; 1,250 meters of the
facility boundary. ,
EPA used the preliminary Facility
Surrey data on distance to all wells
within one mile downgradient and the
number of people served at each well to
calculate the total population risk (i.e.,
number of predicted cancer cases). EPA
calculated the mean number of well-
using people per acre (i.e., 1.6) using
facility survey results for private and/or
public wells. The land area associated
with each exposure well was multiplied
by this population density to estimate
the size of the exposed population for
each affected well.
Ground-water concentrations of
chemical constituents released from
landfills can cause human exposure via
drinking water. All exposed individuals
are assumed to weigh 70 kilograms and
drmk two liters of water per day. The
lifetime dose is calculated as the
running 70-year average over an
individual's lifetime.
(d) Impacts: Human Health Risk. For
this analysis, reported risk is the
average lifetime maximum exposed
individual risk (i.e., the mean of the
average lifetime (70-year) risks over the
300-year modeling period).
Of the eight COG selected for
modeling human health risk, five are
carcinogens and one is a noncarcinogen.
The approach for estimating risks for
carcinogenic effects is consistent with
the Agency's cancer risk assessment
guidelines. Carcinogenic potencies are
from the Agency's Carcinogenic
Assessment Group (i.e., 95th percentile
upper-bound slopes based On a
linearized multistage model). - "
For noncarcinogenic effects, the
Weilbull equation was used with a
threshold to predict a probability of
effect. Below the threshold, risk equals
zero. At doses above the threshold, risk
depends on the dose, the constituent-
specific threshold, and the shape of the
dose-response curve.
(e) Impacts: Resource Damage. The
measure of resource damage in the
model is based on the cost to replace
contaminated ground water that
currently is used, or may be used, for
drinking water. Resource damage is
determined by plume area, the density
ot drinking water wells, the source of
replacement water and its distance from
the affected wells, the time the plume
first appears, and whether ground water
currently is used.
The Agency assumed that the
replacement source is nearby ground
water located one mile distant. The
: replacement well system was designed
using the. mean population density of 1.6
people per acre that also was used for
the human health risk estimates.
Resource damage was estimated
under two scenarios: use value and
option lvalue. Use value assumes that
the population currently is using the
ground, water, whereas option value is
used when tiie population is not
currently using theresourcebut may
wish to do so in the future. For option
value, ihe resource damage measure
recognises the probabilistic, nature of
future use; replacement costs are
multiplied by an estimated probability
of use in each time period. The present
value for both option and use value is
then determined at a 3-percent real
discount rate. •
(f) Corrective Action.Under the
proposed rule, corrective action can be
triggered if a constituent of concern is
detected in the uppermost aquifer at
levels exceeding the applicable MCL; if
an MCL does not exist, a risk-based or
background level is used as the
standard.
• In the corrective action analysis for
this RIA, ground-water monitoring wells
are located at the POC, which can vary
between the landfill unit and the
property boundary depending on tha
regulatory scenario. EPA estimated the
effects of corrective action based on
detection of constituents of concern in
the uppermost aquifer at levels
exceeding a lx 10~5 risk level.
As stated in the cost methodology,
only ground-water recovery wells were
modeled as the corrective action
technolo,gy. The submodel assumes that
the corrective action technology is in
place one year after the trigger levels
are reached and operates at its specified
efficiency for the remainder of the
modeling period. The model calculates
downgradient well concentration
profiles foUowing implementation of the
corrective action and recalculates risk
and resource damage estimates. These
results are compared to the estimates
calculated for the baseline (i.e., no
corrective action scenario) to determine
the reductions in risk and resource
damage achieved by corrective action.
(2) Risk Model Inputs. EPA modeled
three MSWLF sizes for risk and resource
damage: 10 TPD, 175 TPD, and 750 TPD.
Each size category is characterized by
the total volume of waste placed in the
landfilL the number of phases used to
dispose of the waste, and the ,
dimensions of the landfill at capacity
(e.g., surface area, depth, height). The
waste volumes and dimensions for ea ch
capacity category are consistent with
-------
33392
the cost modol described earlier. The
number of phases in the risk analysis
are 2.5, and 10 for the 10,175, and 750
TPD landfills, respectively.
As with the cost model, EPA used the
Facility Survey to estimate the
frequency with which each landfill size
category occurs nationwide. Landfills
with capacities of up to 30 TPD are
included hi the 10 TPD category, 30 to
500 TPD landfills are in the 175 TPD
units, and those with larger capacities
are modeled as 750 TPD. Using this
approach, 61.5 percent of the landfills
were modeled at 10 TPD, 33.1 percent as
175 TPD, and 5.5 percent as 750 TPD.
"The Agency assumed that facility size is
independent of hydrogeologic and
exposure attributes.
All new MSWLFs are assumed to
operate for 20 years. The baseline
facility is the same as that used in the
cost analysis but risks and resource
damage estimates (for the proposal)
were not adjusted to reflect existing
State requirements for containment
systems. This adjustment for liners and
leachate collection systems would affect
no more than 17 percent of all MSWLFs.
To assess the effectiveness of a
regulatory option, EPA assumed that a
new landfill is constructed at the same
site and operated for 20 years plus post-
closure care according to the applicable
requirements.
Under the proposed option, MSWLF
units are required to meet a performance
standard by applying appropriate cover
and containment designs. Owners or
operators have the freedom to choose
the type of design they think will meet
the performance standard. Because the
performance and costs of design
elements such as liners and covers are
highly dependent on site-specific
factors, there are likely to be several
types of designs (and combinations of
designs) chosen by the regulated
community to comply with the
performance standard.
As stated previously, to analyze the
proposed role, EPA assigned
containment and cover designs to new
MSWLFs according to a 10"5 design goal
(chosen from the allowable protective
range of 1X10~* to IXIO"1). In addition.
EPA assigned one of three containment
and cover designs under the assumption
that owners or operators will use the
least stringent design capable of meeting
the design goal (EPA recognizes that
other control technologies beyond the
three analyzed could be used to comply
with the performance standard). If the
most stringent of the three designs did
not reduce risk to this level, corrective
action would be triggered.
Landfills with average lifetime risks
below 1X10"5 given the baseline design
(xuilined with a vegetative cover) were
excluded from further design
requirements. Landfills with higher risks
were assigned a synthetic cover and, if
risks for an MSWLF unit still exceeded
the design goal, the most stringent
design of a synthetic liner, synthetic
cover, and leachate collection system
was assigned. For existing facilities,
EPA used the baseline risks with a
1X10"5 cutoff to assign either a
synthetic cover (for those with greater
than 1X10~5 baseline risks) or a
vegetative cover (for those with less
than 1 X10~5 baseline risks).
For this analysis, EPA assumed that
extended care continues for 80 years
after the end of the active life of the
MSWLF, and includes maintenance of
the vegetative portion of the cover,
ground-water monitoring, and corrective
action (although an extended care
period is analyzed in the RIA, the actual ,
proposed rule requires a two-phased
post-closure care period of at least 30
years). For designs with synthetic
covers, EPA assumed that the synthetic
components would be maintained and
replaced if necessary until the end of the
first 30 years of post-closure care.
EPA modeled Alternatives 1 through 3
in a manner consistent with the cost
analysis. A detailed discussion on how
EPA estimated risk and resource
damage for the regulatory alternatives is
included in the RIA.
b. Risk Results. This part presents
results of the risk analysis (including
resource damage) for the baseline and
each of the regulatory options.
(1) Baseline. For the baseline, EPA
estimates that average MEI risks over
the 300-year modeling period range from
approximately 1X10~4 to zero. Results
from the Facility Survey indicate that
about 54 percent of landfills have no
drinking water wells within one mile of
the facility boundary. Because the model
only estimates human health risks at
drinking water wells within one mile of
the facility, EPA assigned these facilities
(54 percent of all MSWLFs) no human
health risk. EPA recognizes that if future
wells are located near existing landfills,
this subgroup (54 percent) of all
MSWLFs would face potential risks in
the baseline from contaminated ground
water similar to those that currently
have nearby wells. Another 6 percent
have nearby wells, but have no risk
(MEI less than or equal to 1X10"10)
because no constituents reach the wells
within the modeling period. Risks are
low (lX10~«to 1X10"8) or very low
(less than 1X10"8) for a total of 82.8
percent of MSWLFs (these MSWLFs
include the 54 percent of all facilities)
that have no drinking water wells within
.one mile and, therefore, have an
assigned zero health risk). Of the
remainder, 11.6 percent have moderate
risk (i.e., in the 1X10"8 to IX 10"->range),
5.5 percent have high risk (1X10 s to
IX10"*), and a negligible 0.05 percent
exceedlXlO"4. Across all units in the
baseline, less than 20 percent have risks
greater than 1X10" 6. EPA recognizes
that future increases in well density
near MSWLFs would increase baseline
risks from those estimated.
The principal constituents .. . •
contributing to the risk estimates from
the model are vinyl chloride, 1,1,2,2-
tetrachloroethane, and dichloromethane
(methylene chloride). These risk (and
resource damage) estimates are based
on observed median concentrations. The
Agency estimates that the risk
associated with the 90th percentile
levels in the leachate data would be
about one order of magnitude higher
• than that simulated for the median :
concentrations. This risk occurs because
carcinogens are the primary contributors
to risk in this analysis, cancer risk
varies linearly with dose, and the
reported 90th percentile concentrations
are about one order of magnitude higher
than the median levels.,The leachate
data on which these risk estimates are
made are extremely limited. Therefore,
the risk estimates could change
significantly with more comprehensive
leachate data.
The Agency estimates that 0.0770
cancer cases per year in the baseline
can be expected over the 300-year
modeling period. EPA has only
estimated risks from drinking ground
water, and, therefore, additional risks
would exist from other routes of
exposure (e.g., surface Water, subsurface .
gas, and ecosystem risk). Risks
attributable to existing contamination
also are not considered.
Moreover, if future wells are located
near existing MSWLFs (or new sites are
located near current wells), the overall
risk distribution will reflect the
estimates for the subset of landfills that
currently have wells within one mile of
the facility boundary. For this subgroup
of the population, nearly 40 percent of
landfills have risks exceeding 1X10"6. In
addition, the median risk is about
4.3X10"'.
EPA performed a sensitivity analysis
of the baseline risk results to the well
distance distribution. When all landfills
are assumed to have wells at the facility
boundary (modeled as 10 meters
downgradient from the waste unit
boundary for this sensitivity analysis)
risk changes dramatically. While less
than 20 percent of all MSWLFs have
risks exceeding lX10"sfor the actual
well distribution, over 67 percent exceed
-------
August 30, 1988 / Proposed Rules
33393
this risk level when all exposure is
assumed to occur at the 10-meter
boundary.
The results of the analysis identify
several factors that are important in
determining risk, namely facility size,
distance to nearest well, and
environmental setting. These factors
interact with many others in a complex
manner to produce risk.
Higher levels of contamination and,
thus, higher risks are associated with
larger facilities that have a greater mass
of waste. The high percentage of small
facilities (less than 30 tons per day) in
the regulated universe tends to weigh
the overall distribution to lower risk
levels. However, the Agency's economic
impact results indicate that smaller
communities will have incentive to
regionalize their landfill operations in
order to share the burden of cost
increases with other communities as
well as to take advantage of the
economies of scale associated with
larger facilities. Regionalization would
shift the overall risk distribution
towards the higher risks associated with
larger facilities, although the total
number of facilities would be reduced.
All other factors held constant, risk
decreases with increasing distance from
the facility. Contaminant concentrations
diminish over distance due to
degradation, dispersion, and
attenuation. While the closest wells
present the greatest risk, results from
the Facility Survey indicate that this
occurrence is relatively rare: 54 percent
of existing MSWLFs have no wells
within one mile, 15 percent have wells
within 300 meters, and 25 percent have
wells within 500 meters. However, as
stated above, the proximity of wells to
MSWLFs likely will increase in the
future and thus baseline risks and the
risk reduction attributable to the
proposal would be greater than the
estimates based on the current well
distribution.
Wetter climates are associated with
higher release volumes and
consequently greater risks. However,
because landfills are' almost equally
likely to be found in wet or arid
climates, no one infiltration rate setting.
has a dominant influence on the overall
risk distribution. Hydrogeologic
characteristics of the aquifer also exert
a strong influence on risk. Aquifer
properties affect the extent of dilution of
the leachate and the retardation and
degradation of specific pollutants.
Aquifers with slow velocities [i.e., one
meter per year) generally allow for no
pollutant breakthrough at the more
distant wells and for considerable
pollutant degradation before
breakthrough at nearby wells. In the
high-velocity flow fields (i.e., 1,000 and
10,000 meters per year), considerably
more water flows through the aquifer,
which affords more dilution of the
leachate. Intermediate velocity aquifers
(i.ei, 10 and 100 meters per year) have
higher risk profiles because they neither
allow for much degradation nor provide
for much dilution or pollutant
dispersion.
Although these factors (i.e., facility
size, distance from the facility,
infiltration rate, aquifer characteristics)
are strong determinants of risk, no single
factor is responsible for most of the
variability. All of these factors, plus
others that were not accounted for in
EPA's risk modeling, interact in a
complex manner to produce risk.
(2) Regulatory Options. This Subpart
will present first the results for the IO-
meter POC modeled at 10 meters from
the waste boundary and then the 150-
meter POC modeled at 150 meters from
the waste boundary.
For the 10-meter POC, EPA estimated
that, for about 61 percent of all landfills,
vegetative covers alone are sufficient to
meet a 1X10~5 risk-based performance
standard. Synthetic covers are sufficient
for 11 percent of the landfills, while
synthetic liners with leachate collection
systems and synthetic covers are
needed at the remaining 28 percent.
About 40 percent of the landfills with
synthetic liners and covers (11 percent
of all landfills) trigger corrective action
under the proposal.
About 0.1 percent of the landfills have
risks exceeding 1 X10~5 under the
proposal, compared to 5.6 percent in the
baseline and about 35 percent have risks
between 1X10~8 and 1X10~5. Population
risks for the proposal are 0.0210 cancer
cases per year (over the 300-year
modeling period), down from a baseline
of 0.0770 cases per year.
At the 150-meter POC, EPA estimated
that about 79 percent of the landfills are
in compliance with the performance
standard in the baseline (compared to 61
percent with the 10-meter POC). About 9
percent need synthetic covers and the
remaining 13 percent need synthetic
liners and covers. About 5 percent of all
landfills trigger corrective action.
As with the 10-meter POC, the number
of landfills with risks exceeding 1X10"5
,is reduced from 5.6 percent hi the
baseline to about 0.1 percent at the 150-
meter POC. About 86 percent of the
landfills have risks lower than 1X10"6
under this option, compared to 83
percent in the baseline. Population risks
are 0.0227 cancer cases per year (over
the 300-year modeling period), down
from a baseline of 0.0770 cases per year.-
Under Alternative 1, less than 1
percent of the MSWLFs have high risk
(greater than 1X10'5), compared to 5.6
percent in the baseline. Approximately
6.1 percent have moderate risks (1X10~8
to 1X10"^) compared to 11.6 percent in
the baseiline; 15.2 percent have low risks
(1X10-* to 1X10-6); and the remaining
78.7 percent have very low or no risks.
Corrective action is never triggered
during the first 50 years under
Alternative 1, so all of the risk reduction
results from the containment system and
cover. Giverall, about 9 percent of the
landfills trigger corrective action under
Alternative 1. The cover reduces the
amount of infiltration entering the
landfill. Before leachate is released from
the MSWLF, both synthetic membranes
must fail, and the leachate then must
travel through three feet of clay. Due to
this dela.y, which ranges from 52 to over
100 years, some of the pollutant mass
that would otherwise have been
released is not released during the
modeling period. The delay also results
in additional pollutant degradation prior
to release. The leachate collection
systems remove some of the pollutant
mass from the landfill.
EPA estimates that population risks
under Alternative 1 are 0.0086 cancer
cases per year (over the 300-year
modeling period), reduced from the
estimate of 0.0770 cancer cases per year
in the ba.seline.
Under Alternative 2, risk shifts from
the moderate- and high-risk ranges to
the low iind very low categories. Only
0.03 percent of die landfills have risks
exceeding IXIQ-5, and 7.9 percent have
risks between 1X10~6and ixiO"5,
compared to 5.6 and 11.6 percent in the
baseline;, respectively. The percentage of
landfills with risks below 1X10~6
increases from about 83 percent in the
baseline to about 92 percent under
Alternative 2. The expected number of
cancer cases under Alternative 2 is
0.0105 per year (over the 300-year
modeling! period), compared to 0.0770 in
the baseline.
Under Alternative 3, 0.003 percent of
landfills have risks higher than 1XIO"4,
and 1.8 percent have risks between
lX10-6and 1X10"4. The percentage
with risks between 1X 1Q~8 and 1XW~s
decreases from 11.6 in the baseline to 8.7
percent Hinder Alternative 3. Population
risks under this alternative are 0.0216
cancer cases per year over the 300-year
modeling period.
Of all the alternatives considered,
EPA believes the proposed rule is likely
to effectively reduce risk because of the
performance standard nature of the
proposal. Risk depends on a complex
interaction among site-specific factors.
This variability affects not only the
occurrence of risk, but also the
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Federal Register / Vol. 53, No. 168, Tuesday, August 30,1988J Proposed^Rules^
offccliveness of a particular design.
Expressing a regulation in terms of
performance allows for the
implementation of design and operating
procedures that best address site-
specific risk factors. Overall, EPA
believes that risk is likely to be very low
under the proposed option.
Although Alternative 3 requires
extended care, it does not require liners
or leachate collection systems. With this
design, many landfills, particularly those
located in the wetter climates, will
release leachate to the aquifer during
the unit's active life. As a result of these
early releases, EPA estimates that
corrective action will be triggered more
often than under the proposal (39
percent compared to 5 and 11 percent).
Because of the uncertainty in the
effectiveness of corrective action, risk
may be higher under this alternative
than estimated in the RIA (this
uncertainty, however, is not easily
modeled). Alternative 3 represents a
reactive approach to potential
contamination compared to preventive
approaches such as the proposed or
Alternative 2, in which landfill design is
based in part on achieving a
performance standard.
Table 9 shows the number of cancer
cases expected annually over the 300-
year modeling period, and the reduction
in annual population risk for each
regulatory option. As estimated by EPA,
the reductions hi risk are similar among
all the regulatory options.
TABLE 9.—PREDICTED POPULATION RISK
ACROSS 6,034 NEW MSWLPs
Regulatory scsnario
Rflg/ij|rta
Proposal: 10-metor
POO™™™™.,,.
Proposal: 150-matcr
POC . _™».
Attofn&tivo 1 »»».».»....
Alternative 2™.,,
Cases per
year1
0.0770
.0210
.0227
.0036
.0105
.0216
Reduction
(Cases/year)
0.0560
.0543
.0659
.065
.0554
1 Total population risk over ttw 300-year simula-
tion period d&iod by 300.
c. Resource Damage Results.
Consistent with the risk analysis,
resource damage estimates are made for
the baseline, proposed rule, and each
regulatory alternative. As discussed in
the methodology section, resource
damage is measured as the replacement
cost (expressed in present value terms)
to provide water to users whose supply
is contaminated by releases of leachate
from MSWLFs. Similar to the risk
analysis, EPA has not considered the
surface water pathway in the resource
damage analysis. Resource damage
estimates (modeled for new facilities
only) do not .take into account existing
State requirements for containment
systems. .
(1) Baseline. The Agency estimates
significant resource damage in the
baseline for MSWLFs ranging from $0 to
more than $4 million. The majority of
MSWLFs, however, have resource
damages valued at less than $200,000;
this result largely reflects the option
value estimate for the 54 percent of all
MSWLFs that have no drinking water
wells within one mile of the facility.
EPA predicts that about 29 percent of
MSWLFs will have no resource damage.
Approximately 31 percent of landfills
have resource damage exceeding
$200,000, and about 13 percent have
resource damage in excess of $1 million.
The two components of resource
damage are not option value and use
value. Because option value is based on
the probability that a ground-water
source may someday be used, it tends to
be much lower than use value for a
given set of conditions; option value is
estimated to be typically one-tenth of
use value. Option value dominates at
lower levels of resource damage while
use value is the only measure to appear
at levels exceeding $400,000.
When both use and option value are
considered, the median resource damage
is about $79,000.13-percent of the
MSWLFs have damages exceeding $1
million, and 7-percent have damages ,
exceeding $2 million. If only use value is
considered, the median estimate for
resource damage for this subset of
landfills (i.e., the 46 percent of all
MSWLFs that report drinking water
wells within one mile) is about $485,000,
and almost 28 percent of these MSWLFs
have damages that exceed $1 million.
The total resource damage for all
6,034 MSWLFs in the baseline is
approximately $2.58 billion.
Facility size, distance to nearest-well,
and environmental setting have an
influence on resource damage similar to
their influence on the risk estimates
presented earlier^
Generally, the resource damage
, estimates are heavily dependent on the
current status of ground-water use,
plume size, and the timing of
contamination. Because ground water in
.the vicinity of more than half the
MSWLFs is not currently used, most
contamination causes resource damage
that has relatively low present value. In
some cases, however, resource damage
can be extensive, valued at as much as
$5 million. Environmental factors have
an impact on resource damage by
affecting plume size and its timing.
(2) Regulatory Options, Resource
damage under the proposal reduces the
replacement costs from the baseline.
Under the proposal at the 10-meter POC,
EPA estimates that no landfills will have
replacement costs exceeding $3 million"
(present value), compared to over .3
percent in the baseline. The fraction of
landfills with replacement cost between
$1 million and $3 million.decreases from
9.5 percent in the baseline to 6.5 percent
under the proposal. The percentage of
landfills with no resource damages is
the same for both the baseline and
proposal (28.6 percent). EPA estimates
that the total resource damage across all
landfills is $1.27 billion, a reduction of
$1.31 billion from the baseline estimate -
of $2.58 billion.
Under the proposal at the 150-meter
POC, the shift to lower replacement
costs is smaller than with the 10-meter
POC. Under the 150-meter POC, EPA
estimates that there are no landfills with
resource damage greater than $3 million.
Seven percent have replacement costs
between $1 and $3 million, and 64.3
percent have positive resource damage
less than $1 million. The total resource
damage across all landfills is $1.6 .
billion, which is $980 million less than
the baseline but $33 million more than
under the 10-meter POC."
Under Alternative 1, no MSWLFs
have replacement costs exceeding $1
million, whereas about 13 percent have
replacement costs exceeding $1 million
in the baseline. The fraction of MSWLFs
with replacement costs between $0.2
million and $1 million decreases from
one-fifth to one-tenth under Alternative
1. Over half of the MSWLFs have zero
resource damage with Alternative 1
requirements in place, compared .to 29
percent hi the baseline. The total
resource damage across all MSWLFs is
$410 million, a reduction of $2.17 billion
from the baseline.
The synthetic/composite liner, double
leachate collection system, and
composite cover reduce resource
damage for the same reasons that they
reduce risk. As with risk, there is no
resource damage estimated in the 0.25-
inch net infiltration region because
releases do not.occur within the first 100
years. If the pollutant release period in
the model were extended, it is likely
some resource damage would be
simulated. None of the reduction in.
resource damage results from corrective
action, which is never triggered during
the first 50 years under Alternative 1.
EPA estimates that Alternative 2
effectively reduces resource damage. .
Virtually none of the landfills have
resource damages exceeding $1 million,
compared to about 17 percent in the
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j Federal Register / Vol. 53. No. 168. Tuesday, August 30. 1988 / Proposed J Rules
33395'
baseline. The percent of landfills with
resource damage between $0.2 million
and $1 million decreases from 15.1
percent in the baseline to 12.8 percent
under Alternative 2. About 35 percent of
the landfills have no resource damage.
The total resource damage across all
landfills decreases from $2.58 billion in
the baseline to $570 million under
Alternative 2 for a reduction of $2.01
billion. -
Alternative 3 eliminates the
occurrence of replacement costs higher
than $4 million. About 6.4 percent of the
landfills have replacement costs
between $1 million and $4 million. The
number of landfills with no resource
damage remains virtually unchanged
from the baseline at about 29 percent.
The total resource damage across all
landfills under Alternative 3 drops from
$2.58 billion to $1.57 billion as a result of
corrective action.
In summary, all of the regulatory
options reduce resource damage from
baseline levels. For each option, the
largest reductions occur for those
facilities that currently have
downgradient wells (i.e., resource
damage is. measured in terms of use
value) and install preventive measures
to control releases. At these facilities,
the reduction and delay in releases to
the subsurface reduce plume size and/or
delay formation of plumes. Because
replacement costs are discounted, delay
in plume formation translates directly
into reduced resource damage. Those
facilities with no current wells have
smaller baseline resource damage"
(measured as option value), but also
have proportionately smaller damage
reductions because they are not as
strongly affected by the delay in
leachate release. Table 10 presents the .
resource damage results, across all 6,034
new MSWLFs, for the regulatory
options.
TABLE 10.—TOTAL RESOURCE DAMAGES
FOR 6,034 NEW FACILITIES
[Present value in billions of dollars]
Regulatory scenario
Baseline
Proposal (10-rneter POC).....
Proposal (150-State POC) ...
Alternative 1
Alternative 2...
Alternative 3
Resource
damage
$2 58
1.27
1.60
0 41
0 57
1 57
Damage
reduction
$1.31
0.98
B. Regulatory Flexibility Act
The Regulatory Flexibility Act (RFA)
requires Federal regulatory agencies to
evaluate the impacts of regulations on
small entities. The RFA requires an
initial screening analysis to determine
whether the proposed rule will have a
significant impact on a substantial
number of small entities.
This section presents the methodology
and results of the Agency's screening
analysis for the proposed rule at the 10-
meterpoint of compliance.
1. Methodology
The RFA provides some guidance hi
developing definitions of what
constitutes a substantial number of
small entities, what size criteria define a
small entity, and what is a significant
impact, although it allows the Agency to
develop a more appropriate definition if
necessary. The Act defines a
"substantial number" as more than 20
percent of the affected population of
small entities. The RFA provides a
definition of a small governmental entity
as any government serving a population
of less than 50,000.
The RFA allows for several indicators
(e.g., compliance costs as a percentage
of production costs, compliance costs as
a percentage of sales, number and
proportion of small entities likely to
close) to be used to assess significant
impacts. When a recommended
threshold is exceeded for a given
indicator, this constitutes a "significant
impact."
For this RFA screening analysis, the
Agency used the same measures and
threshold levels as those used hi the
economic impact analysis. These
indicators (and the corresponding
threshold values) are cost as a
percentage of expenditures (1-percent),
cost per household ($220 per year), and
cost as a percentage of median
household income (1-percent).
2. Results
As stated in the economic impact
analysis results, the threshold values are
never exceeded for CPH or at the IO-
meter POC for the proposed rule. Tables
11 and 12 present data on cost per
household and cost as a percentage of
expenditures for the proposed rule at the
10-meter POC. (The pattern of impacts is
very similar for costs as a percentage of
median household income and is not
displayed.) The two indicators show
similar patterns of impact with the
greatest impacts on communities with
populations of 5,000 or less. The
threshold value for significant impact is
exceeded for the cost as a percentage of
expenditures indicator.
TABLE 11.—COST PER HOUSEHOLD PER
YEAR FOR PROPOSED RULE (IO-METER
POC)_
[Percent of households by community size]
Population
size '
Less thari
1,000
1,001-
5,000.......
5,001- i
15,000.:...
15,001- :
50,000....:
50,001-
100,0001...
More than
100,000;...
CPH range (in percent)
<$25
72.9
80.8
87.5
88.9
88.5
98.0
$25-$50
25.2
15.9
10.8
9.9
11.5
2.0
$50-$100
1.9
3.1
1.7
1.1
• 0.0
0.0
>$100
0.0
0.3
00
0.0
0.0
0.0
TABLE 112.—COMPLIANCE COST AS PER-
CENTAGE OF EXPENDITURES FOR PRO-
POSED RULE (1 O-METER POC)
[Percent of communities by community size]
, Population siza
Less than 1,000
1,001 to 5,000 „...
5,001 to 115,000.
15,001 to 50,000 r.
50,001 to 100,000
Greater than 100,000,..
Percent of
expenditures
0-1%
78.8
85.6
90.0
90.9
87.7
100.0
1-2%
18.9
10.5
7.8
5.6
12.3
0.0
>2%
2.3
4.0
2.2
3.6
0.0
0.0
Although the RFA is aimed primarily
at mitigating adverse effects on small
businesses, it also includes a definition
of small governmental entities as any
government serving a population of less
than 50,000. The municipal data base of
primary providers of local government
services used for this analysis contains
about 29,017 entities, 97.6 percent of
these represent a population of 50,000 or
smaller. Because such a large proportion
of affected entities under the proposed
rule meets the 50,000 population
criterion suggested in the RFA, and
since sigilificant adverse impacts are •
less on entities with a population larger
than 5,000, an alternative definition of a
small entity is appropriate. There are
22,191 entities in the data base with
populations of 5,000 or less; this
represents 77 percent of the total, The
proposed regulation will have its most
severe impacts on governments serving
less than 1,000 people, which include 46
percent of primary local governments.
Therefore, the Agency determined that
an appropriate size definition for small
entities for the purpose of this analysis"
falls somewhere between governments
of 5,000 persons and 1,000 persons.
The Agency determined that the
proposed rule is likely to impose
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33396
Feiieral Register'/ 'Vol. 53, No; 168,'Tuesday,'August 30, J988
differential economic impacts, although
not significant impacts, on a substantial
number of small entities. The impacts
are more severe on small governments
than those on larger communities. The
Agency determined that the effects of
the proposed rule on small entities
should be analyzed in greater detail as
part of the final rulemaking effort.
C. Limitations
There are several important caveats
to the results presented in this section.
Costs and benefits for the proposed rule
as estimated in the RIA represent a 1 X
10"8 design goal, actual effects of the
proposal will vary as the State-
specified-design goal varies within the
allowable protective range of 1 X 10~*
to 1 X 10~7. Moreover, other designs
besides the three modeled in the RIA
would be sufficient to meet the
performance standard and would
influence the resulting costs and
benefits. Although several provisions
(e.g., post-closure care, ground-water
monitoring parameters, performance
standard for existing units) of the
proposal do not exactly reflect what
was analyzed in the RIA, the Agency
believes that the basic conclusions of
the RIA are accurate estimators of the
effects of the proposed rule.
Compliance costs represent upper-
bound estimates. Factors that may act to
reduce the cost estimates including
regionalization, waste shifts to resource
recovery facilities, recycling, and better
siting of new landfills in "good"
locations. As noted earlier, EPA has not
incorporated these factors into the
analysis because they involve site-
specific local decisions that are difficult
to analyze.
It is unlikely that each of the existing
MSWLFs will have a replacement
landfill in perpetuity as EPA has
assumed in this analysis due to such
forces as regionalization. Smaller
MSWLFs can achieve substantial
economies of scale that will help to
reduce their compliance costs by
participating in larger regional landfills
with other local governments. The
economies of scale likely will remain
positive even with additional costs due
to transfer stations and increased
transportation distances. Although these
economies of scale exist, there are many
local, noneconomic (e.g., political,
technical) factors that enter into landfill
siling that may inhibit the forces of
regionalization.
Future waste shifts to resource
recovery facilities will divert the waste
volume that potentially needs to be
landfilled, and, thus, costs presented hi
this section will tend to be overstated. It
is likely that solid waste combustion
will become more attractive hi the future
due to competitive costs with landfilling
or favorable environmental conditions
at a given site. EPA has estimated that
resource recovery could divert as much
as 18 percent of the solid waste stream
away from land disposal given future
population growth and increases in the
volume of solid waste generated (Ref.
16). Alternatives to land disposal other
than energy recovery also exist (e.g.,
recycling, composting). These programs,
although often successful due to their
inherent flexibility and cost-
effectiveness, have historically diverted
only modest amounts of municipal solid
waste from the waste stream.
EPA has adjusted the compliance
costs to reflect State requirements for
liners, leachate collection systems, and
ground-water monitoring wells; no
adjustment was made hi the benefits
analysis, which used an unlined unit ,
with a vegetative cover to represent
baseline conditions. Estimated costs
may be overstated for landfills in States
with other requirements that may be
similar to the proposed rule.
There are also several caveats related
to the risk analysis. There is
considerable uncertainty hi the risk
modeling. The model components that
introduce the most uncertainty are those
that predict: (1) Leachate quality for
trace organics, (2) the probability and
consequences of containment system
failure, (3) the effectiveness of corrective
action, and (4) the human health risk
resulting from exposure to toxic
substances (i.e., the dose-response
models).
The risk analysis also considers only
the current population that is using the
ground water as a drinking water
source. In the future, greater numbers of
people and wells may be located near ,
MSWLFs. Future population growth
would increase the risk reduction
estimates presented in this discussion. If
regionalization occurs so that the total
number of landfills that needs to be
sited is reduced, the total exposed
population may also be reduced.
However, EPA has shown that larger
risks are associated with larger
facilities. Future population growth, and
- a corresponding increase in solid waste
generation that may be land disposed,
will also increase compliance costs over
, the current estimates.
EPA estimated only risks that are
attributable to drinking contaminated .
ground water. Other risks from MSWLFs
were not analyzed (e.g., surface water,
subsurface gas, risks to the ecosystem).
Analyzing these risks would result in
greater risk reduction than currently
estimated. The aggregate costs already
include some of the controls that would
prevent these other forms of risk. The
bulk of the compliance costs are for
requirements that serve to protect the
ground water from leachate
contamination.
EPA's modeling period in the risk
analysis is 300 years. Greater risk
reduction would be obtained if this
period were extended.
Many assumptions, such as those
discussed above, enter into the risk
analysis. Thus, strong reliance on the
absolute risk estimates without full
realization of the limitations of the
analysis should be avoided. .
Comparisons of the risk estimates ,
across regulatory options are more
reliable and valid than absolute
estimates for a single option. EPA
solicits comments and additional data
regarding the assumptions, costs, risks,
and potential impacts identified in the
regulatory analysis.
D. 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 of 1980, 44 U.S.C. 3501 et seq.
Submit comments on these requirements
to the Office of Information and
Regulatory Affairs; OMB; 726 Jackson ,
Place, NW; Washington, B.C. 20503,
marked "Attention: Desk Officer for
EPA." The final rule will respond to any
OMB or public comments on the
information collection requirements.
XII. References
A. Background Documents
(1) U.S. EPA, OSW. Notification
Requirements for Industrial Solid Waste
Disposal Facilities—Criteria for
Classification of Solid Waste Disposal
Facilities and Practices (40 CFR Part
257)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). August 1988 (draft).
(2) U.S. EPA, OSW. Location
Restrictions (Subpart B)—Criteria for
Municipal Solid Waste Landfills (40 CFR
Part 258)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). July 1988 (draft).
(3) U.S. EPA, OSW. Operating Criteria
(Subpart C)—Criteria for Municipal.'.
Solid Waste Landfills (40 CFR Part
258)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). July 1988 (draft).
(4) U.S. EPA, OSW. Closure/Post-
Closure Care and Financial
Responsibility Requirements (Subpart C,
§ § 258.30-258.32)—Criteria for
Municipal Solid Waste Landfills (40 CFR
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federal R.^g^7_Vojt:--53. No. 168, Tuesday,: August 30, 1988 '/,|'rqpQ3edTRules;
33397
Part 258)—Subtitle D of the Resource
Conervation and Recovery Act [RCRA).
July 1988 (draft).
(5) U.S. EPA, OSW. Design Criteria
(Subpart D)—Criteria for Municipal
Solid Waste Landfills (40 CFR Part
258)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). July 1988 (draft).
(6) U.S. EPA, OSW. Ground-Water
Monitoring and Corrective Action
(Subpart E)—Criteria for Municipal
. Solid Waste Landfills (40 CFR Part
258)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). July 1988.
(7) U.S. EPA, OSW. Case Studies on
Ground-Water and Surface Water
Contamination from Municipal Solid
Waste Landfills—Criteria for Municipal
Solid Waste Landfills (40 CFR Part
258)—Subtitle D of the Resource
•Conservation and Recovery Act
(RCRA). July 1988 (draft).
(8) U.S. EPA, OSW. Summary of Data
on Municipal Solid Waste Landfill
Leachate Characteristics—Criteria for
Municipal Solid Waste Landfills (40 CFR
Part 258)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). July 1988.
(9) U.S. EPA, OSW. Updated Review
of Selected Provisions of State Solid
Waste Regulations—Criteria for
• Municipal Solid Waste Landfills (40 CFR
Part 258)—Subtitle D of the Resource
Conservation and Recovery Act
(RCRA). July 1988.
B. Regulatory Impact Analysis
(10) as. EPA. OSVS. Draft Regulatory
Impact Analysis (RLA) of Proposed
Revisions to Subtitle D Criteria for
Municipal Solid Waste Landfills—
Criteria for Municipal Solid Waste
Landfills (40 CFR Part 258)—Subtitle D
of the Resource Conservation and
Recovery Act (RCRA). August 1988.
C. GuidanceDocuments
(I}) U.S. EPA, OSW. Criteria for
Identifying Areas of Vulnerable
1 iydrogeplogy Under the Resource
Conservation and Recovery Act,
Statutory Interpretative Guidance,
• Guidance Manual for Hazardous Waste
Land Treatment, Storage, and Disposal
Facilities. Interim Final. July 1988.
(12) U.S. EPA, OSW. Guidance
Document on Classifying Solid Waste
Disposal Facilities, SW-828. March 1980.
(13) US. EPA. OSW. Permit Writers^ .
Guidance Manual for Hazardous Waste
Land Storage and Disposal Facilities,
Chase I Criteria for Location
Acceptability and Existing Applicable
Regulations, final draft. February 1985.
D, Other References :
(14) Abt Associates Inc. National
Small Quantity Generator Survey.
Contract No. 66-01-6892. U.S.
Environmental Protection Agency,
Office of Solid Waste. Washington, DC
1985.
(15) Farrell, J. B. and G. K. Dotson.
"The Effects of Municipal Wastewater
Sludge on Leachates and Gas
Production From Sludge-Refuse
Landfills. U.S. EPA/ORB. 1987.
(16) Franklin Associates, Ltd.
Characterization of Municipal Solid
Waste in the United States, 1960 to 2000.
U.S. Environmental Protection Agency,
Washington, DC June 1986.
(17) Franklin Associates, Ltd.
Characterization of Municipal Solid
Waste in the United States, 1960 to 2000.
(1988 Update) U.S. Environmental
Protection Agency, Washington, DC.
March 1988.
(18) GCA Corporation and Booz, Allen.
& Hamilton Inc. Review of Federal and
State Regulations and Other Information
on Disposal of Solid Waste in Wetlands.
Contract No. 68-01-6871. U.S.
Environmental Protection Agency,
Washington, DC December 1986.
(19) ICF Incorporated. Case Studies of
State Financial Responsibility Programs
for Subtitle D Solid Waste Disposal
Facilities (Draft). March 1987.
, (20) ICF Incorporated. The Uner
Location Risk and Cost Analysis Model:
Phase II. (Draft) 1986.
f21) ICF Incorporated. Survey of State
Closure and Post-Closure Regulations
For Solid Waste Facilities. (Draft). May
1987.
(22) PEI Associates, Inc. State Subtitle
D Regulations on Solid Waste Landfills,
Surface mipoundments, Land
Application Units and Waste Piles.
Contract No. 68-01-7075/02-3890. U.S.
Environmental Protection Agency,
Washington, DC 1985.
(23) Planning Research Corporation.
Evaluation of NPL/Subtitle D Landfill
Data. U.S. Environmental Protection
Agency, Washington, DC. May 1986.
(24) Pohland, F. G. andF. R. Harper.
Critical Review and Summary of
Leachate and Gas Production From
Landfills. August 1986.
(25) Random-Walk Solute Transport
Model for Selected Ground Water
Quality Evaluations, 1931. Bulletin No.
65. Illinois State Water Survey.
, (26) Science Applications
International Corporation. Summary of
Data on Industrial Nonhazardous Waste
Disposal Practices. Contract No. 68-01-
7050, U.S. Environmental Protection
Agency, Washington, DC 1985.
(27) SCS Engineers. A Survey of
Household Hazardous Wastes and
Related Collection Programs. Contract
No. 68-01-6621. U.S. Environmental
Protection Agency, Washington, DC
. Octobeir 1986.
(28) U.S. EPA, OSW. Subtitle D Study
Phase I Report, EPA/530-SW-86-054.
Octobeir 1986.
(29) U.S. EPA, OSW. Industrial
Subtitle D Facility Study, List of
Questions in Telephone Survey.
September 1986.
(30) U.S. EPA, OSW. Survey of Solid
Waste (Municipal) Landfill Facilities.
August 1988.
(31) U.S. EPA,OSWER. '
Understanding the Small Quantity'
Generator Hazardous Waste Rules: A
Handbook for Small Business.
September 1986.
(32) U.S. EPA, OSW. Notification of
Hazardous Waste Activity, Form 8700-
12 and instructions. Revised November
1985. ; -
(33) U.S. EPA. EPA Journal, Vol 12,
No. 1. January/February 1986.
(34) U.S. EPA, OSW. Test Methods for
Evaluating Solid Waste Physical/
Chemitial Methods (SW-846). September
1986. I
(35) U.S. EPA, OSW. Water Balance
Method for Predicting Leachate.
Generation from Solid Waste Disposal
Sites. EPA publication number 530/SW-
168.1975. ,
(36) U.S. EPA, OSW. Lining of Waste
Impoundment and Disposal Facilities
(SW-870). 1983.
(37) U.S. EPA, OWPO, "Financial
Capability Guidebook."February 1983.
(38) WEST AT, Inc. Census of State ,
arid Territorial Subtitle D Nonhazardous
Waste ftograms. Contract No< 68-01-
7047. U.S. Environmental Protection
Agency,; Washington, DC 1986.
(39) UfS. EPA, OGWP. DRASTIC: A
Standardized System for Evaluating
Ground-Water Pollution Potential Using
Hydrog«ologic Settings, EPA/600/2-85/
018.1985.
(40) U.S. EPA, OSW. Process Design .
Manual-—Municipal Sludge Landfills.
EPA—625/1-78-010. October 1978.
XIII. List of Subjects
A. 40 CFR Part 257
Reporting and record keeping
requirements, Waste disposal.
B. 40 CfR Part 258
Reporting and record keeping
requirements, Household hazardous
waste, Vlfaste disposal, Security
measures, Water pollution control,
Liquids in landfills, Small quantity
generators, Corrective action, Liner
requirements.
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33398
Federal, Register / Vol. 53, No. 168. .Tuesday, August :30,
Date: August 23.1968.
Leo M. Thomns,
Administrator,
For reasons set out in the preamble,
Title 40 of the Code of Federal
Regulations Is proposed to be amended
as set forth below:
PART 257—CRITERIA FOR
CLASSIFICATION OF SOLID WASTE
DISPOSAL FACILITIES AND
PRACTICES
1, The authority citation is revised to
read as follows:
Authority: 42 U.S.C. 6907ta)(3}, 6944(a] and
0049«(c), 33 U.S.C. 1345 (d) and (e).
2. Section 257.1 is amended by adding
paragraph (c)(10) to read as follows:
§ 2S7.1 Scope and purpose.
• ««•«*
tc) * * *
(10) The criteria of this part do not
apply to municipal solid waste landfills,
which are subject to the revised criteria
contained in Part 258 of this title.
««
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-ederal
.
August 30, 1988 / Proposed Ki
-APPENDIX: I
United States Environmental Protection Agency
Wesrii.Tgton, D.C. 20460
Motiflcgfion for Industrial Solid Waste
Disposal Facilities and
Construction/Demolition Waste Landfills
Agency Use Only
ID Number
Form Approved
Date Received
1. Facility Owner
I. Owner and Locattonal Information
Owner Nama (Corporation, Individual. Public Agency, or
Other Agency).
Street Address or P.O. Box. City, State, and Zip Code
Telephone Number (Including Area Code and Extension)
2. Location of Facility
Establishment or Facility Name ;and Address
(Street Address or location Descrption (not P.O. Box)
(®.g., 3 miles wast of the intersection of Highway 355
and Routs $4). City/County. State, and rip Code)
Telephone Number (Including Arsa Code a/id Extension^
Latitude
Degrees I Minutes
3. Nams of Contact Person (Mark the box it contact person is owner)
4. If this establishment is a facility operated or owned by tha
Federal Government, enter the GSA Identificatfon Number
n
Longitude
Degress 1 Minutes
Telephone Number
(Including Area Code and Extension)
II. General Facility Information
i ! -I I I- I I' I ! L
1. Which of the Folbwing Unit Types Are at
This Facility? Enter the number of each unit type at this
facility. H this facility doss not have a unit type, anter "0.")
Type of Unit
Construction/Demolition
Wasls LandfrM
Industrial Solid Wasta Landfill
i'nyust'r'/ai'Saltd Wasla
Surface Impoundment
Industrial Solid Wasts Land
Industrial Solid Waste Pile
2. Waste Types Disposed of at This Facility (Check aff that sppty. toclwS« wastes that
currently are accepted or have b&sn acceptsd in tfie past)
Municipal Solid Waste
Asbestos-Containing
Waste Material
Infectious Wastes
Small Quantity
Generator Waste
D
Sewage Sludga I J
Municipal Incinerator Ash 1 J Oth«r
Other Incinerator Ash
Industrial Solid Wasta
ConstrueSion/
Demolition Was'a
Number at Facility
3. Total Annual Amount
Disposed of at This
Facility
(Enter th0 quantity and
chock tha appropriate
unM of measurement.)
Cubic Yards
Quantity
33399
-330-
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33400
Federal Register / Vol. 53. No. 168 / Tuesday, August 30.1988 / Proposed Rules
HI. Exposure Information
{You may need to contact a local planning agency, water authority,
or health department for information nesded to complete question 1.)
1. Number of Households Within One Mi!« of the Facility
'X~ In the box if the number is «n estimate?
n
2 Number of Upgradient and Downgradiant Ground-water
' Monitoring Wells at thb Facility
Upgradient Walls j Downgradiont Write
IV. State Information
V. Certification
T^rtifyljnderpenalty of law that \ have personally examinedand am familiar wah the formation submitted JJthfc
aSd\S SSied doo.merrts and that, based on my inquiry of those individuals invnedftely responsible .forewarning.
the Wofmatfon, I believe that the submitted informatksn is true, accurate, and complete.
Nam« and official fitte of owner, operator or authorized
representative
Signature
Dale Signed
EPA Form 9410-1 (7-S8)
-331-
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Federal
30; 1988 / P] oposed Rules
33401
WHO MUST NOTIFY?
EXHIBIT A
I WITH )
V BOX1 I
1. Does your facility manage
any of the following:
• Garbage
• Refuse
• Sludge
• Solid, liquid, semi-solid
or contained gaseous
material that is discarded
or served its purpose
• Mning or manufacturing
by-product?
You must notify if your fecifily/manages RCRA solid waste that is:
Not regulated as hazardous under Subtitle C of RCRA and
Industrial or construction/damolition waste, and
Disposed of in a landfill, surface impoundment, tend application
unit or waste pito.
Use^the decision, chart betow to datermina if you must notify
Begin with Box 1. Answer ihe questions and follow the arrows
corresponding to your responses. You will finish the series
of questions with a tircie that will indicate whether or not you
should notify.
YES
I
NO
DO NOT
NOTIFY
Your facility
doss not manage
RCRA solid
waste
2. Is tha material excluded from
regulation under RCRA
because it is one of the
following: (Refer to
40CFR261.4)
1) Domestic sewage
2) CWA point sourcs discharge
. 3) Irrigation return flow
4) AEC source, special nuclear
or by-product material
5) In-situ mining waste
3. Is tha waste regulated
as hazardous at this facffity?
(Refer to 40 CFR
Part 261 todetermins if
4. Is ths waste at this facility
Industrial waste or
construction/
demolition waste?
YES
5, Is the waste disposed of in
one of tha following:
• Landfills
• Surface impoundments
• Land application units
Waste piles
DO NOT
NOTIFY
Your facility
manages waste
excluded from
RCRA
ula
DO NOT
NOTIFY
Your facility
does not manage
waste in
disposal uni
YOUR
FACILITY MUST
NOTIFY
MS-BOOS
-332-,
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Federal Register / Vol. 53, No. 168 / Tuesday^August 30-^988^
Notification for Industrial Solid Waste Disposal
Facilities and Construction/Demolition Waste
Landfills
The U S Environmental Protection Agency (EPA) is evaluating solid waste landfills,
surface impoundments, land application units, and waste piles in response to the
Hazardous and Solid Waste Amendments of 1984 (HSWA). These arnenclrnents modified
Subtitle D of the Resource Conservation and Recovery Act of 1976 (RCRA), under which
EPA sets Federal standards and guidelines for solid waste disposal facilities. Subtitle D
facilities manage solid wastes that are not regulated as hazardous wastes under Subtitle C of
RCRA As part of this evaluation, EPA is compiling data on industrial solid waste disposal
frdlities and construction/demolition waste landfills that manage Subtitle D wastes by
requiring those facilities to complete and return the notification form found on pages ^
through 5 of this booklet,
General Information
Authority!; Authority for this notification is found in Sections 2002, 3007, and 4010 of
the Resource Conservation and Recovery Act, as amended
Puruose- The primary purpose of this notification is to provide EPA with data on the
number and types of industrial solid waste disposal facilities and to evaluate the potential
exposure to wastes managed at these facilities.
Who Must Notify: Facilities with existing construction/demolition waste landfills and
industrial solid waste landfills, waste piles, surface impoundments, and land application
units that manage nonhazardous Subtitle D wastes are required to notify Do not include
units used to manage hazardous wastes regulated under Subtitle C of RCRA. Refer to
Exhibit A to help you determine whether you must notify.
Where To Notify: The owner or operator of a construction/demolition waste landfill or
an industrial solid waste landfill, surface impoundment, waste pile, or land applicationi unit
must send the completed notification form to EPA and the State (address, name and phone
number of State and EPA contracts are attached). Facilities have six months after the
effective date of the rule to notify.
When To Notify: Existing facilities have six months after the effective date of the rule to
notify.
Penalties' Anv owner or operator who knowingly fails to notify or submits false
aSSon^lTsubjwt toPa civil penalty not toVxceed $25,000 for each unit at the
facility for which notification is not given or for which false information is submitted
Additional Information: For additional information, the notifier may contact the
RCRA/CERCLA Hotline at (800) 424-9364 or (202) 382-3000.
Definitions
Please read the following before answering the questions.
Commercial solid waste is all types of solid waste generated by stores, offices, restaurants
wSIses, and other nonmanufecturing activities, excluding any residential or industrial
wastes.
EPA Form 9410-1 (7-88) .
-333-
-------
l_: n l ,,J^er^ Re^ste* f,^ 33403
Construction/Demolition Waste is waste building materials, packaging, and rubble resulting
from die construction, remodelling, repair, and demolition operations on pavements
houses, commercial buildings, and other structures. Such wastes include, but are not
limited to, bricks, concrete, other masonry materials, soil. rock, lumber, road "spoils n-bar
paving material, and tree stumps. ' . '
Disposal is the discharging, depositing, injecting, dumping, spilling, leaking, or placing
solid waste into or on any land or water so that such solid waste or any constituent thereof,
may enter the environment, be emitted into the air, or discharged into any waters, including
ground waters.
Dbwngradient Well is a well located in the flow path of ground water that has passed under
a facility.
Facility means all contiguous land and structures, other appurtenances, and improvements
on the land used for the disposal of solid waste. A facility may include more than one unit
Units found at & facility include the following.
• Land application unit is an area where wastes are applied onto or into the soil
surface (excluding manure-spreading operations) for agricultural purposes or for
treatment and disposal. Common names are landspreading, landfarming, or Hand
treatment.
• Surface impoundment is a natural or human-made depression in the ground fonsied
mainly of earthen materials and is designed to hold liquid wastes or wastes
containing free liquid. Common names are ponds, pits, or lagoons. >
• Waste pile is a noncdntainerized mass of solid, nonflowing waste material mat may
or may not be enclosure by a fence, a cover, or some other structure. Waste piles
can be used for treatment or storage. . i
• Landfill is an area of land or an excavation in which wastes are placed for
permanent disposal, and that is not a land application unit, surface impoundment
injection well, or waste pile. ;
Hazardous Waste is solid waste regulated under 40 CFR Part 261. The regulafory
definition of hazardous waste is found at 40 CFR 261.3.
Household Solid Waste is any solid waste including garbage, trash, and sanitary wastes in
septic tanks generated by single or multiple residences, hotels, motels, bunkhouses, rariger
stations, crew quarters, or any recreational areas such as campgrounds and picnic grounds.
Industrial Solid Waste is solid waste generated by manufacturing or industrial processes
that is not a hazardous waste regulated under Subtitle C of RCRA. Such waste may
include, but is not limited to, wastes resulting from the following manufacturing processes:
electric power generation; fertilizer/agricultural chemicals; food and related products/by-
products; inorganic chemicals; iron and steel manufacturing; leather and leather products;
nonferrous metals manufacturing/foundries; organic chemicals; plastics and resins
manufacturing; pulp and paper industry; rubber and miscellaneous plastic products; stone,
glass, clay, and concrete products; textile manufacturing; transportation equipment; iand
water treatment. This term does not include mining waste or oil and gas waste. • j •
Infectious Waste is any disposable equipment, instruments, utensils, or fomiites
(substances that may carry pathogenic organisms) from rooms of patients who have been
diagnosed or are suspected of having a communicable disease; laboratory wastes such as
tissues, blood specimens, excreta, and secretions from patients or laboratory animals;
EPA Form 9410-1 (7-88) '""''•
-------
Federal Register / Vol. 53/1^.16^ / fu^y. Migust
! I; i ,),.-lit
disposable fomites; and surgical operating room pathologic specimens, fomites, and other
materials rrom outpatient areas and emergency rooms.
Municipal Incinerator Ash is the residue from burning municipal solid waste. The ash is
usually produced in two fractions, fly ash and bottom ash, but typically is disposed of in a
combined form.
Municipal Solid Waste is any household, residential, and commercial solid waste.
Residual is any material left over at the end of an industrial process that is not sold as a
product. Residuals can include solids, liquids, and sludges.
RCRA is the Resource Conservation and Recovery Act of 1976, the Federal statute that
the treatment, storage, and disposal of hazardous and nonhazardous solid waste.
Small Quantity Generator is a generator that generates no more than 100 kg/month of
hazardous waste.
Solid Waste is any garbage, refuse, or sludge from a waste tteatment
tfeatment plant, orlir pollution control facility and other discarded matenal, i
solid liamd semisolW, or contained gaseous material resulting from industrial,
SaSSfiiSSnd agricultural operations, and from ^^^^7"^^^
rSTlude solid or dissolved material in domestic sewage, or solid or dissolved material in
Stior "return flows or industrial discharges that are point sources subject to permits
wder 33 USC1342 or source, special nuclear, or by-product matenal as defined by the
Atomic Energy Act of 1954, as amended (68 Stat. 923).
Storage is the temporary holding of waste, after which it is treated, disposed of, or stored
elsewhere.
Treatment is any process that changes the chemical, physical, or biological character of a
waste.
Upgradien* Well is a well located in the flow path of groundwater before it passes under a
facility. .
Waste is anv material that results from a production or treatment process and is not sold as
a p^uctThTs SdS wastes that are managed in waste piles and surface unpoundments
even if they are eventually recycled.
Wastewater is anv water that is used in an industrial process but is not part of the product
water.
EPA Form 9410-1 (7-08)
BILUNO COOE SS«*-50-C
-335-
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Federal
53. No. J68, Tuesday, August 30. 1QB8 /Proposed Rules
33405
7. A new Part 258 is added as set forth
below:
PART 258—CRITERIA FOR MUNICIPAL
SOLID WASTE LANDFILLS
Subpart A—General
Sac. .
258.1 Purpose, scope, and applicability.
258.2 Definitions.
258.3 Consideration of other Federal laws.
258.4-258.9 [Reserved].
Subpart B—Location Restrictions
258.10 A jrport safety.
258.11 Floodplains.
258.12 Wetlands. '
258.13 Fault areas.
258.14 Seismic impact zones.
258.15 Unstable areas.
258.16-258.19 [Reserved],
Subpart C—Operating Criteria
258.20 Procedures for excluding the receipt
of hazardous waste.
258.21 Cover material requirements.
258.22 Disease vector control.
258.23 Explosive gases control.
258.24 Air criteria.
258.25 Access requirements.
258.26 Run-on/run-off control systems.
258.27 Surface water requirements.
258.28 Liquids restrictions.
258.29 Recordkeeping requirements.
258.30 Closure criteria.
258.31 Post-closure care requirements.
258,32 Financial assurance criteria.
258.33-258.39 [Reserved].
Sabpart D—Design Criteria
258.40 Design criteria.
258.41-258.49 [Reserved].
Subpart E—Ground-Water Monitoring and
Corrective Action
258.50 Applicability.
258.51 Ground-water monitoring systems.
258.52 Determination of ground-water
trigger level.
258.53 Ground-water sampling and analysis
requirements.
258.54 Phase I monitoring program.
258.55 Phase II monitoring program. .
258.56 Assessment of corrective measures.
258.57 Selection of remedy and
establishment of ground-water protection
standard.
258.58 Implementation of the corrective
action program.
258.59 [Reserved].
Appendix I—Volatile Organic Constituents
• for Ground-Water Monitoring. ,
Appendix II—Hazardous Constituents.
Appendix III—Carcinogenic Slope Factors
(CSFs) and Reference Doses (RfDs) for
Selected Hazardous Constituents.
Authority: 42 U.S.C. 6907(a)(3), 6944{a) and
6949[c); 33 U.S.C. 1345 [dj and {e).
Subpari A—General
§ 258.1 Purpose, scope, and applicability.
(a) The purpose of this part is to
establish minimum national criteria
under the Resource Conservation and
Recovery Act (RCRA or the Act), as
amended, for municipal solid waste
landfills and under the Clean Water Act,
as amended, for municipal solid waste
landfills that are used to dispose of
sludge. These minimum national criteria
ensure the protection of human health
- and the environment.
(b) These criteria apply to owners and
operators of new and existing municipal
solid waste landfills, except as
otherwise specifically provided in this
part; all other solid waste disposal
facilities and practices that are not
regulated under Subtitle C of RCRA are
subject to the criteria contained in Part
257.
(c) These criteria do not apply to
closed units (as defined in this section)
,of municipal solid waste landfills that
close prior to the effective date of this
part.
(d) Municipal solid waste landfills
failing to satisfy these criteria are
considered open dumps for purposes of
State solid waste management planning
underRCRA.
(e) Municipal solid waste landfills
failing to satisfy these criteria constitute
open dumps, which are prohibited under
section 4005 of RCRA. -
(f) Municipal solid waste landfills
containing sewage sludge and failing to
satisfy these criteria violate sections 309
and 405(e) of the Clean Water Act.
(g) The effective date of this part is
[insert date 18 months after the
promulgation date], unless otherwise
specified.
§258.2 Definitions.
Unless otherwise noted, all terms
contained in this part are defined by
their plain meaning. This section
contains definitions for terms that
appear throughout this part; additional
definitions appear in the specific
sections to which they apply.
"Active life" means the period of
operation beginning with the initial
receipt of solid waste and ending at
completion of closure activities in
accordance with § 258.30 of this part.
"Active portion" means that part of a
facility or unit that has received or is
receiving wastes and that has not been
closed in accordance with § 258.30 of
this part.
"Aquifer" means a geological
formation, group of formations, or
portion of a formation capable of
yielding significant quantities of ground
water to wells or springs.
• "Closed unit" means any solid waste
disposal unit that no longer receives
solid waste as of the effective date of
this part and has received a final layer
of cover material.
"Commercial solid waste" means all
types of solid waste generated by stores,
offices, restaurants, warehouses, and
other nonmanufacturing activities,
excluding residential and industrial
wastes.
"Existing unit" means any solid waste
disposal unit that is receiving solid
waste as of the effective date of this part
and has not received a final layer of
cover material.
"Facility" means all contiguous land
and structures, other appurtenances,
and improvements on the land used for
the disposal of solid waste.
"Ground-water" means water below
the land surface in a zone of saturation.
"Household waste" means any solid
waste (including garbage, trash, and
sanitary waste in septic tanks) derived
from households (including single and
multiple residences, hotels and motels,
bunkhouses, ranger stations, crew
quartern, campgrounds, picnic grounds,
and dajr-use recreation areas).
"Industrial solid waste" means solid
waste generated by manufacturing or
industrial processes that is not a
hazardous waste regulated under
Subtitle C of RCRA. Such waste may
include, but is not limited to, waste
resulting from the following
manufacturing processes: Electric power
generation; fertilizer/agricultural .
chemicals; food and related products/
by-products; inorganic chemicals; iron
and steel manufacturing; leather and
leather products; nonferrous metals
manufacturing/foundries; organic
chemicals; plastics and resins
manufacturing; pulp and paper industry;
rubber and miscellaneous plastic
products; stone, glass, clay, and
concrete products; textile
manufacturing; transportation
equipment; and water treatment. This
term does not include mining waste or
oil and gas waste.
"Landfill" means an area of land or an
excavation in which wastes are placed
for permanent disposal, and that is not a
land application unit, surface
impoundment, injection well, or waste
pile, as those terms are defined under
§257.2. | ,
"Lateral expansion" means a
horizontal expansion of the waste
boundaries of an existing landfill unit.
"Leaehate" means a liquid that has
passed tlirough or emerged from solid
waste and contains soluble, suspended,
or miscible materials removed from such
waste. !
"Municipal solid waste landfill"
means any landfill or landfill unit that
receives household waste. This landfill
also may receive other types of RCRA
Subtitle I) wastes, such as commercial
-------
33406
Federal Regster /Vol. 53, No. M8y .Tuegday,,
waste, nonhazardous sludge, and
Industrial solid waste. Such a landfill
may fac publicly or privately owned.
"New unit" means any solid waste
disposal unit that has not previously
received solid waste prior to the
effective date of this part. Anew unit
also means lateral expansions as
defined in this section.
"Open burning" means the
combustion of solid waste: without!
(1) Control of combustion air to
maintain adequate temperature for
efficient combustion,,
(2) Containment of the combustion
reaction in an enclosed device to
provide sufficient residence time and
mixing for complete combustion, and
(3), Contra! of the emission of the
combustion products.
"Operator" means the person
responsible for the overall operation of a
facility or part of a facility.
"Owner" means the person who owns
a facility or part of a facility.
"Run-off" means any rainwater,
leachate, or other liquid that drains over
land from any part of a facility.
"Run-on" means any rainwater,
leachate, or other liquid that drains over
land onto any part of a facility.
"Saturated zone" means that part of
the earth's crust hi which all voids are
filled with, water.
"Sludge" means any solid, semi-solid,
or liquid waste generated from a
municipal, commercial, or industrial
wastewater treatment plant, water
supply treatment plant, or air pollution
control facility exclusive of the treated
effluent from a wastewater treatment
plant.
"Solid waste" means any garbage,
refuse, sludge from a waste treatment
plant, water supply treatment plant, or
air pollution control facility and other
discarded material, including solid,
liquid, semi-solid, or contained gaseous
material resulting from industrial,
commercial, mining, and agricultural
operations, and from community
activities, but does not include solid or
dissolved materials, in domestic sewage,
or solid or dissolved materials in
irrigation return flows or industrial
discharges that are point sources subject
to permits under aatLS.C. 1342, or
source, special nuclear, or by-product
material as defined by the Atomic
Energy Act of 19S4> as amended (6& Stat.
923).
"Solid waste disposal unit" means a
discrete area of land used for the
disposal of liolid wastes.
"State" means any of the several
States, the District of Columbia, the
Commonwealth of Puerto Rico, the
Virgin Islands, Guam, American Samoa,
and the Commonwealth of the Northern;
Marianas Islands.
"Waste management unit boundary"
means, a vertical surface located at the
hydraulically downgradient limit of the
unit. This vertical surface extends down
into the: uppermost aquifer.
§ 258.3 Consideration of other Federal
laws.
The owner or operator of a municipal
solid waste landfill unit must comply
with any other applicable Federal rules,
laws, regulations, or other requirements.
§§258.4-258.9 [Reserved].
Subpart B—Location Restrictions
§ 258.10 Airport safety.
A municipal solid waste landfill unit
that may attract birds and iff located
within 10,000 feet (3,048 meters) of any
airport runway used by turbojet aircraft
or within 5,000 feet (1,524 meters); of any
airport runway used by only piston-type
aircraft shall not pose a bird hazard to
aircraft.
§ 258.11 Floodplalns.
(a) A municipal solid waste landfill
unit located in the 100-year floodplain
shall not restrict the flow of the 100-year
flood,, reduce the temporary water
storage capacity of the floodplain, or
result in washout of solid waste so as to
pose a hazard to human health and the
environment.
(b) For purposes of this section:
(1J "Floodplain" means the lowland
and relatively flat areas adjoining inland
and coastal waters, including flood-
prone areas of offshore islands,, that are
inundated by the 100-year floodt
(2) "100-year flood" means a flood
that has a 1-percent or greater chance of
recurring hi any given year or a flood of
a magnitude equalled or exceeded once.
in 100 years on the average over a
significantly long period.
(3) "Washout" means the carrying
away of solid waste by waters, of the
base flood.
§258.12 Wetlands.
(a) New municipal solid waste landfill
units shall not.be located in wetlands,
unless the owner or operator can make
the following demonstrations to the
State:
(1) There is no. practicable alternative
that Would have less, adverse: impact on
the wetlands and would have no other
significant adverse environmental
consequences;
(2) The landfill will not:
(i) Cause or contribute to violations of
any applicable State water quality
standard,
(ii) Violate any applicable toxic
effluent standard or prohibition under.
Section 307 of the Clean Water Act;
(iil) Jeopardize toe continued
existence of endangered or threatened
species or result in the destruction, or •
adverse modification of a critical
habitat, protected under the Endangered
Species Act of 1973, and
(iv) Violate any requirement under the
Marine Protection, Research, and
Sanctuaries Act of 1972 for the
protection of a marine sanctuary;
(3) The landfill wilt not cause or
contribute to significant degradation of
wetlands;
(4) Appropriate and practicable steps
have been taken to minimize potential
adverse impacts of the landfill on the
wetlands; and
(5) Sufficient information is available
to make a reasonable determination
with respect to these demonstrations;
(b) As used in this section, "wetlands"
means those areas that are inundated or
saturated by surface or ground'water at
a frequency and duration- sufficient to
support, and that under normal
circumstances do support,, a prevalence
of vegetation, typically adapted far life
hi saturated soil conditions. Wetlands
include, but are not limited to*, swamps^
marsheSr. bogs, and similar areas.
§258.13 Fault areas.
(a) New units of a municipal solid
waste landfill shall not be, located
within 200 feet (60*meters) of a fault that
has had displacement in Holocene time.
(b) For the purposes of this1 section:
(1) "Fault" means a fracture along
which strata on one side have- been
displaced with respect to that on the
other side.
(2) "Displacement" means the relative
movement of any two sides of a fault
measured in any direction.
(3) "Holocene" means the most recent
epoch of the Quaternary period,
extending from the end of the
Pleistocene to the present.
§258.14 Seismic Impact zones.
(a) At a new municipal solid waste
landfill unit located in a "seismic impact
zone," all containment structures,
including liners, leachate collection.
systems, and surface water control
systems,, must be designed to resist the
maximum horizontal acceleration in
lithified material for the site>
(b) As used in paragraph (a) of this
section, "seismic impact zone" means air
area with a 10 percent or greater
probability that the maximum horizontal
acceleration in hard rock, expressed as-
a percentage of the earth's-gravitational
pull (g), will exceed O.lOg in 250-years.
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(c) As used in paragraph [a) of this
section, the "maximum horizontal
acceleration in lithified material" means
the maximum expected horizontal
acceleration depicted on a seismic
hazard map, with a 90 percent or greater
probability that the acceleration will not
be exceeded in 250 years, or the
maximum expected horizontal
acceleration based on a site-specific
seismic risk assessment.
§258.15 Unstable areas.
[a) The owner or operator of a
municipal solid waste landfill unit
located in an unstable area must
demonstrate to the State that
engineering measures have been
incorporated into the unit's design to
ensure the stability of the structural
components of the unit. The owner or
operator must consider the following
factors, at a minimum, when
determining whether an area is
unstable:
(1) On-site or local soil conditions that
may result in significant differential
settling;
. (2) On-site or local geologic or
geomorphologic features; and
(3] On-site or local human-made
features or events (both surface and
subsurface).
' (b) As used in this section, "structural
components" means liners, leachate
collection systems, final covers, run-on/
run-off systems, and any other
component .necessary for protection of
human health and the environment.
(c) Existing units of a municipal solid
waste landfill located in unstable areas
that cannot make the demonstration
specified in paragraph (a) of this section
must close within 5 years of the
effective date of this part in accordance
with § 258.30 of this part and conduct
post-closure activities in accordance
with § 258.31 of this part.
fd) The deadline for a closure required
by paragraph (c) of this section may be
extended by the State after considering,
at a minimum, the following factors:
(1) Availability of alternative disposal
capacity; and
(2) Potential risk to human health and
the environment.
§§258.16-258.19 [Reserved].
Subpart C—Operating Criteria
§258.20 Procedures for excluding the
receipt of hazardous waste.
(a) The owner or operator of a
municipal solid waste landfill unit must
implement a program at the facility for
detecting and preventing the disposal of
regulated hazardous wastes as defined
in Part 261 of this title and
polychlorinated biphenyls (PCB) wastes
as defined in Part 761 of this title. This
program must include at a minimum:
(1) Random inspections of incoming
loads;
(2) Inspection of suspicious loads;
(3) Records of any inspections;
(4) Training of facility personnel to
recognize regulated hazardous waste;
and
(5) Procedures for notifying the proper
authorities if a regulated hazardous
waste is discovered at the facility.
(b) As used in this section, "regulated
hazardous waste" means a solid waste
that is a hazardous waste, as defined in
40 CFR 261.3, that is not excluded from
regulation as a hazardous waste under
40 CFR 261.4(b) or was not generated by
a conditionally exempt small quantity
generator as defined in § 261.5 of this
title.
§ 258.21 Cover material requirements.
(a) The owner or operator of a
municipal solid waste landfill unit must
cover disposed solid waste with suitable
materials at the end of each operating
day, or at more frequent intervals if
necessary, to control disease vectors,
fires, odors, blowing litter, and
scavenging. ' . .
(b) The State may grant a temporary
waiver from the requirement of
paragraph (a) of this section if the State
determines that there are extreme
seasonal climatic conditions that make
meeting such requirements impractical.
§258.22 Disease vector control.
(a) The owner or operator of a
municipal solid waste landfill unit must
prevent or control on-site populations of
disease vectors using techniques
appropriate for the protection of human
health and the environment.
(b) For purposes of this section,
"disease vectors" means any rodents,
flies, mosquitoes, or other animals,
including, insects, capable of
transmitting disease to humans.
§258.23 Expiosivs gases control!.
(a) The owner or operator of a
municipal solid waste landfill unit shall
ensure that:
(1) The concentration of methane gas
generated by the facility does not
exceed 25 percent of the lower explosive
- limit for methane in facility structures
(excluding gas control or recovery
system components); and .
(2) The concentration of methane gas
does not exceed the lower explosive
limit for methane at the facility property
boundary.
(b) The owner or operator of a
municipal solid waste landfill unit must
implement a routine methane monitoring
program to ensure that the standards of
paragraph (a) of this section are met.
(1) The type and frequency of
monitoring must be determined based
on the following factors:
(i) Soil conditions;
(ii) The hydrogeologic conditions
surrounding the disposal site;
(iii) The hydraulic conditions
surrounding the disposal site; and
(iv) The location of facility structures
and property boundaries.
(2) TJie minimum frequency of
, monitoring shall be quarterly.
(c) If methane gas levels exceeding
the limits specified in paragraph (a) of
this section are detected, the owner or
operator must:
(1) Take all necessary steps to ensure
immediate protection of human health;
(2) Immediately notify the State of the
methane gas levels detected and the
immediate steps taken to protect human
health; and
(3) Within 14 days, submit to the State
for approval a remediation plan for the
methane gas releases. The plan shall
describe the nature and extent of the
problem and the proposed remedy. The
plan shall be implemented upon
approval by the State.
(d) As used in this section, "lower
explosive limit" means the lowest
percent by volume of a mixture of
explosive gases in air that will
propagate a flame at 25"C and
atmospheric pressure.
§258.24 Air criteria.
(a) A municipal solid waste landfill
shall not violate any applicable
requirements developed under a State
Implementation Plan (SIP) approved or
promulgated by,the Administrator
pursuant to section 110 of the Clean Air
Act, as amended.
(b) Opien burning of solid waste,
except for the infrequent burning of
agricultural wastes, sih/icultural wastes,
land-clearing debris, diseased trees,
debris from emergency clean-up
operations, or ordnance, is prohibited at
municipid solid waste landfill units.
§258.25 | Access requirement
The oxyner or operator of a municipal
solid waste landfill unit must control
public access and prevent unauthorized
vehicular traffic and illegal dumping of
wastes to protect human health and the
environment using artificial barriers,
natural barriers, or both, as appropriate.
§ 258.26 Run-on/run-off control systems.
(a) The owner or operator of a
municipal solid waste landfill unit must
design, construct, and maintain:
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Federal Register / Vol. 53, Na. 188, Tuesday. August 30, 1988 / Proposed Rules
(1) A run-on control system to prevent
flow onto the active portion of the
landfill during the peak discharge form a
25-year storm;
(2) A run-off control system from the
active portion of the landfill to collect
and control at least the water volume
resulting from a 24-hour, 25-year storm.
(b) Run-off from the active portion of
the landfill unit must be handled in
accordance with § 258.27Ca) of this Part.
§258.27 Surface water requirements.
A municipal solid waste landfill unit
shall not:
(») Cause a discharge of pollutants
into waters of the United States,
including wetlands, that violates any
requirements of the Clean Water Act,
including, but not limited to, the
National Pollutant Discharge
Elimination System CNPDES)
requirements, pursuant to section 402.
(b) Cause the discharge of a nonpoint
source of pollution to waters of the
United States* including wetlands, that
violates any requirement of an area--
wide or State-wide water quality
management plan that has been
approved under section 208 or 319 of the
Clean Water Act, aa amended.
§258.28 Liquids restrictions.
(a) Bulk or nonoontainerized liquid
waste may not be placed in a municipal
solid waste landfill unit unless:
(1) The waste is household waste
other than septic waste; or
(2) The waste is leachate or gas
condensate derived from the municipal
solid waste landfill unit and the landfill
unit is equipped with a composite liner
and a leacfcate collection system, that is
designed and constructed to maintain
less than a 30-cm depth of leachate over
the liner.
(b) Containers holding liquid waste
may not be placed in a municipal solid
waste landfill unit unless:
fl) The container is a small container
similar fa size to that normally found in
household waste;
(2) The container is designed to hold
liquids for use other than storage, such
as a battery or capacitor; or
(3) The waste is hotsehold waste.
\c} As used in this section:
(1) "Composite liner" means a system
consisting of two components; the upper
component must consist of a flexible
membrane liner (FML), the lower
component must consist of at least a-
three-foot layer of compacted soil with a
hydraulic conductivity of no more than
1XI0~T cm/sec. The FML component
must be installed hi direct and uniform
contact with the compacted soil
component so as to .minimize the
migration of leachate through the-FML if
a break should occur.
[2] "Liquid waste" means, any waste
material that is determined to contain
"free liquids," as defined by Method 9095
(Pamt Filter Liquids Test),, as, described
in "Test Methods for Evaluating Solid
Wastes, Physical/ChemicalMethods.'*
(EPA Pub. No. SW-846 I).
(3} "Leachate recirculation" meanathe
recycling, or reintroduction of leachate
into or on a municipal solid waste
landfill unit
[4J "Gas condensate," means the liquid
generated as a result of the gas
collection and recovery process at the
municipal solid waste landfill unit.
§258.29 Recordkecping requirements.
The following information must be
recorded, as it becomes available* and
retained by the owner or operator of
each municipal solid waste landfill unit:
(aj Any monitoring, testing, or
analytical data required by Sufapart E;
(b) Gas monitoring results' from
monitoring required by § 258.23 of this
(c) Inspection nsaords, training
procedures, and notification procedures
required in § 258'.20 of this pairtr and
(d) Closure and post-closure care
plans as required by 1258.30(b): and
§ 258.31(el of tills part.
§258.30 Closure criteria.
(a)The owner or operator of a
municipal solid waste landfill must close
each landfill unit hi a manner that
mmimizes the need for further
maintenance and- minimizes the post-
closure formation and release of
leachate and explosive gases to air,
ground water, or surface water to the
extent necessary to protect human
health and the environment.
(b) The owner or operator must
prepare a written plan that describes the
steps necessary to close all units of the
muncipal solid waste landfill at any
point during its active life in accordance
with the closure performance standard
in § 258.30(a). The closure plan, at a
mhiimum, must include the following
information:
(1) An overall description of the
methods, procedures, and processes that
will be used to close each unit of a ,
municipal solid waste landfill in
accordance with the-closure
performance standard in | 258.30(a),
including procedures for
decontaminating the landfill;
(2) An estimate of the maximum
extent of operation that will be open at
1 Copies may be obtained from: Solid Waste
Information, U.S. Environmental Protection Agency,
28 WestSt ClairSt, Cincinnati, Ohio 45268.
any time during; the active-Me of the (
landfill: j
[:3), An estimate of the maximum
inventory of; wastes: ever on-aite over' .
the active life of the landfill;;
(4) A description. o£the: final cover,
designed in accordance, with
§ § 258.40{bi) and 258.40(c], andj.
(5) A schedule for completing all
activities necessary to satisfy the
closure performance1 standard.
(c) The closure plan must he. prepared
as of the effective date of this part,, or by
the initial receipt of solid, waste,
whichever is later, and must be
approved by the State. Any subsequent
modification to the closure plan also.
must.be approved by the State. A copy
of the most recent approved closure plan
must be kept at the facility or at an
alternate location designated by the
owner or operator until closure of the ,
municipal solid waste landfill has been
certified In accordance with § 258.30[e)
and the owner or operator, has, been
released from, financial assurance
requirements for closure under
§258.32$.
(d) The owner or operator must begin
closure activities, of each landfiE unit* in
accordance with then approved closure
plan, no later than 30 days following.the
final receipt of. wastes; at thai landfill
unit. Extensions of the, deadline for
beginning closure may be granted at the
discretion of the Slate if the owner or
operator of a municipal solid waste.
landfill demonstrates that the landfill
will not pose a threat to human health
and the. environment.
(e); Following: closure of each,
municipal solid waste landfill unit, the
owner or operator must submit to the
State- a certification that objectively
verifies that, closure has been completed
in accordance with the. approved closure
plan, based on a review of the landfill
unit by a qualified party.
§ 258.31 Post-closure care requirements.
(a)-Following closure of each
municipal solid waste landfill unit, the
owner or operator must conduct two,
phases of post-closure care; The first
phase must be for a minimum of 30
years and consist of at least the
following:
(1) Maintaining, the integrity and
effectiveness of any final cover,
including,making repairs, to. the caver aa
necessary to correct the effects of
settling, subsidence-, erosion-,, or other
events, and preventing run-on and run-
off from eroding or otherwise damaging
the-final cover;
(2] Maintaining and operating; the-
leachate collection system in
accordance with the- requirements; in
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'^jL^SL-f^l.1!0'..1^8' ^esdgy.August 30> 1983 / Proposed Rules
§ 258.40(aHb), if applicable* until
leachate no longer is generated;
(3) Monitoring the ground-water in
accordance with the requirements of
§ 258.SO and maintaining the ground-
water monitoring system;, and,
(4) Maintaining and operating the gas
monitoring system in accordance with
the requirements of § 258.23.
(b) Following the period described in
§ 258.31(a), the owner or operator must
conduct a second phase of post-closure
care at each municipal solid waste
landfill unit that consists of, at a
minimum, ground-water monitoring and
gas monitoring. The length of this period
is determined by the State and must be
sufficient to protect human health and
the environment. .
(c) The owner or operator of a
municipal solid waste landfill must
prepare a written post-closure plan that
describes monitoring and routine
maintenance activities that will be
carried out during each phase of the
post-closure care period in accordance
with the requirements of § 258.31(a) and
.(b). The post-closure plan must include,
at a minimum, the following information:
(1) A description of the monitoring
and maintenance activities required in
§ 258.31 (a) and (b) for each unit, and the
frequency at which these activities will
be performed;
(2] Name, address, and telephone
number of the person or office to contact
about the facility during both phases of
the post-closure period; and
(3) A description of the planned uses
of the property during both phases of the
post-closure- care period. Post-closure
use of the property must never be
allowed to disturb the integrity of the
final cover, linerfs], or any other
components of the containment system,
of the function of the monitoring
systems, unless, upon the demonstration
by the owner or operator, the State
determines that the activities will not
increase the potential threat to human
health or the environment or the
disturbance is necessary to reduce a
threat to human health or the
environment. The owner or operator
must obtain approval from the State in
order to remove any wastes or waste
residues, the liner, or contaminated soils
from the laiid.
(d) The post-closure plan must be
prepared as of the effective date of the
rule, or by the initial receipt of solid
waste, whichever is later, and must be
approved by the State. Any subsequent
modification to the post-closure plan
must also be approved by the State. A
copy of the most recent approved post-
, closure plan must be kept at the facility
or at an alternate location designated by
the owner or operator until completion
• of the post-closure care period has been
certified in accordance with § 258.31{f)
and the owner or operator has been
released from financial assurance for
post-closure care under § 258.32(g).
(e) Following closure of the entire
municipal solid waste landfill, the owner
or operator must record a notation on
the deed to the landfill property, or some
other instrument that is normally
examined during title search. The owner
or operator may request permission from
the State to remove the notation from
the deed if all wastes are removed from
the facility in accordance with
paragraph (c)(3) of this section. The
notation on the deed must in perpetuity
notify any potential purchaser of the
property that:
(1) The land has been used as a
municipal solid waste landfill; and
[2) Its use is restricted under •
paragraph (c)(3) of this section.
(f)- Following completion of the two-
phase post-closure care period for each
unit, the owner or operator of an
MSWLF must submit to the State a
certification that objectively verifies
that both phases of post-closure care
have been completed in accordance,
with the approved post-closure plan,
based on a review of the landfill unit by
a qualified party.
§ 258.32 Financial assurance criteria.
(a) The requirements of this section
apply to the owner and operator of each
municpal solid waste landfill, except an
owner or operator who is a State or
Federal government entity whose debts
and liabilities are the debts and
liabilities of a State or the United States.
[b) The owner or operator must have a
detailed written estimate, in current
dollars, of the cost of hiring a third party
to close the municipal solid waste
landfill in accordance with the closure
plan developed to satisfy the closure
requirements in § 258.30 of this part.
(1) The estimate must equal the cost of
closing the landfill at the point in the
municipal solid waste landfill's active
life when the extent and manner of its
operation would make closure the most
expensive, as indicated by its closure
plan (see § 258.30(b) of this part).
(2) During the active life of the
municipal solid waste landfill, the owner
or operator must annually adjust the
closure cost estimate for inflation.
(3) The owner or operator must
increase the closure cost estimate, and
the amount of financial assurance
provided under paragraph (fj of this
section if changes to the closure plan or
landfill conditions increase the
maximum cost of closure at any time
over the active life of the municipal
solid waste landfill.
(4) The owner or operator may request
a reduction in the closure cost estimate
•and the amount of financial assurance
provided under paragraph (f) of this
section if he can demonstrate that the
cost estimate exceeds the maximum cost
of closure at any time over the life of the
landfill.
(5) The owner or operator must keep a
copy of the latest closure cost estimate
at the landfill until the owner or
opera tor has been notified by the State
that he has been released from closure
financial assurance requirements under
paragraph (f) of this section.
(c) The owner or operator must have a
detailed written estimate, in current
dollars,, of the cost of hiring a third party
to conduct each phase of post-closure
monitoring and maintenance of the
municipal solid waste landfill in
accordance with the postclosure plan
developed to satisfy the post-closure
requirements in! § 258.31 (a) and (b) of
this part. The post-closure cost estimate
for each phase of post-closure care used
to demonstrate financial assurance in
paragraph (g) of this section is
calculated by multiplying the annual
cost estimate for each phase of post-
closure care by the number of years of
post-closure care required in that phase.
(1) The cost estimate for each phase of
post-closure care must be based on the
most expensive costs of post-closure
care during that phase.
(2) During the active life of the
municipal solid waste landfill, the owner
or operator must annually adjust the
post-closure cost estimate for inflation.
(3) The owner or operator must
increase the amount of the post-closure
care cost estimate and the amount of
financial assurance provided under
paragraph (g) of this section if changes
in the post-closure plan or landfill
conditions increase the maximum costs
of post-closure care.
(4) The owner or operator may request
a reduction in the post-closure cost
estimate and the amount of financial
assurance provided under paragraph (g]
of this section if he can demonstrate that
the cost estimate exceeds the maximum
costs cif post-closure care remaining
over the post-closure care period.
(5) The owner or operator must keep a
copy of the latest post-closure care cost
estimate at the landfill until he has been
notified by the State that he has been
released from post-closure financial
assurance requirements for the entire
landfill under paragraph (g) of this
section.
(d) An owner or operator of a
municipal solid waste landfill required
to undertake a corrective action
program under § 258.58 of this part must
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Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
have a detailed written estimate, in
current dollars, of the cost of hiring a
third party to perform the corrective
action in accordance with the program
required under § 258.58 of this part. The
corrective action cost estimate is
calculated by multiplying the annual
costs of corrective action by the number
of years of the corrective action
program.
(1) The owner or operator must
annually adjust the estimate for inflation
until the corrective action program is
completed.
(2) The owner or operator must
increase the amount of the corrective
action cost estimate and the amount of
financial assurance provided under
paragraph (h) of this section if the
annual corrective action costs, in
current dollars, for the remaining period
over which corrective action will be
conducted exceed the cost estimate.
(3) The owner or operator may request
a reduction in the amount of the
corrective action cost estimate and the
amount of financial assurance provided
under paragraph (h) of this section if he
demonstrates that the cost estimate
exceeds the maximum remaining costs
of corrective action.
(4) The owner or operator must keep a
copy of the latest estimate of the costs
of performing corrective action at the
landfill until he has been notified by the
State that he has been released from
corrective action financial assurance
requirements under paragraph [h) of this.
section.
(e) The mechanisms used to
demonstrate financial assurance under
this section must ensure that the funds
necessary to meet the costs of closure,
post-closure care, and corrective action
for known releases will be available in a
timely manner whenever they are
needed. Financial assurance
requirements must satisfy the following
criteria:
(!) The financial assurance
mechanisms must ensure that the
amount of funds ensured is sufficient to
cover the costs of closure, post-closure
care, and corrective action for known
releases when needed;
(2) The financial assurance
mechanisms must ensure that funds will
be available in a timely fashion when
needed;
(3) The financial assurance
mechanisms must guarantee the
availability of the required amount of
coverage from the effective date of these
requirements or prior to the initial
receipt of solid waste, whichever is
later, until tho owner or operator
establishes an alternative financial
assurance mechanism or is released
from the financial assurance
requirements under paragraphs (f), (g),
and [h) of this section;
(4) The financial assurance
mechanisms that may be used to satisfy
the requirements in paragraphs (f), (g),
and (h) of this section must provide
flexibility to the owner or operator; and
(5) The financial assurance
mechanisms "must be legally valid and .
binding and enforceable under State and
Federal law.
(f) The owner or operator of each
municipal solid waste landfill must
establish, hi a manner in accordance
with paragraph (e] of this section,
financial assurance for closure of the
landfill, in an amount equal to the most
recent closure cost estimate prepared in
accordance with paragraph [b) of this
section. The owner or operator must
provide continuous coverage for closure
until released from financial assurance
requirements in accordance with this
paragraph. The owner or operator may
be released from financial assurance
requirements for closure after the State
has received certification that closure
has been completed in accordance with
the approved closure plan, as required
under § 258.30(e) of this part Following
receipt of the closure certification, the
State will:
(1) Notify the owner or operator in
writing that he/she is no longer required
to maintain financial assurance for
closure, or;
(2) Provide the owner or operator with
a detailed written statement of any
reason to believe that closure has not
been conducted in accordance with the
approved closure plan.
(g) The owner or operator of each
municipal solid waste landfill must
establish, in a manner in accordance
with paragraph (e) of this section,
financial assurance for the costs of each
phase of post-closure care as required
under § 258.31 (a) and (b) of this part, in
an amount equal to the sum of the most
recent cost estimates for each phase of
post-closure care, prepared in
accordance with paragraph (c) of this
section. The owner or operator must
provide continuous coverage for post-
closure care until released from
financial assurance requirements for
post-closure care under paragraph
§ 258.31(g) of this section. The owner or
operator may be released from financial
assurance requirements for post-closure
care requirements after the State has
received a certification that the two-
phase post-closure care period has been
completed in hi accordance with the
approved plan, as required under
§ 258.31(f} of this part. Following receipt
of the post-closure care certification, the
State will:
[1) Notify the owner or operator in
writing that he is no longer required to
maintain financial assurance for post-
closure caie, or;
(2] Provide the owner or operator with
a detailed written statement of any
reason to believe that post-closure care
has not been conducted in accordance
with the approved post-closure plan.
(h) The owner or operator of each
municipal solid waste landfill required
to undertake a corrective action
program under § 258.58 of this part must
establish, in a manner in accordance
with paragraph (e] of this section,
financial assurance for the most recent
corrective action program, in an amount
equal to the corrective action cost
estimate prepared in accordance with
paragraph (d) of this section. The owner
or operator must provide continuous
• coverage for corrective action until
released from financial assurance
requirements for corrective action in
accordance with this paragraph. The
owner or operator may be released from
financial assurance requirements for
corrective action after the State has
received certification that the corrective
action remedy has been completed in
accordance with the approved
corrective plan, as required by
§ 258.58[e) of this part. Following receipt
of the corrective action certification, the
State will: t
(1) Notify the owner or operator in
writing that he is no longer required to
maintain financial assurance for
corrective action, or; . • •
(2) Provide the owner or operator with
a detailed written statement of any
reason to believe that corrective action
has not been completed in accordance
with the approved corrective action
plan.
§§ 258.33-258.39 [Reserved].
Subpart D—Design Criteria
§ 258.40 Design Criteria.
(a) New municipal solid waste landfill
units must be designed with liners,
leachate collection systems, and final
cover systems, as necessary, to ensure
that the design goal established under -
paragraph (b) of this section is met in
the aquifer at the waste management
unit boundary,'or an alternative
boundary, as specified by the State
under paragraph (d) of this section,
(b) The State must establish a design
goal for new MSWLF units. This design
shall, at a minimum, achieve a ground-
water carcinogenic risk level with an
excess lifetime cancer risk level (due to
continuous lifetime exposure) within the
lX10~«to IXKT'range.
-------
[Note to S 25&40(b): EPA is considering
alternatives to the lX10~4to 1X10"* risk
range. The Agency specifically requests
comment on a fixed risk level of 1X10~5 or an.
upper bound risk level of 1X10"4 (with the
States having discretion to be more stringent)
as alternatives to the proposed risk range. A
fixed risk level of IxltT6 would provide a
uniform level of protection across all States.
On the other hand, setting an upper bound
risk level of 1X 1(T4 would allow States
greater flexibility in establishing more
stringent risk levels based on site specific
conditions].
(c) When establishing the design
necessary to comply with paragraph (a)
of this section, the State shall consider
at least the following factors:
(1) The hydrogeologic characteristics
of the facility and surrounding land;
(2) The climatic factors of the area;
(3] The volume and physical
characteristics of the leachate;
[4) Promixity of gound-water users;
and
(5) Quality of ground water.
(d) A State may establish an
alternative boundary to be used in lieu
of the waste management unit
boundary. The alternative boundary
shall not exceed 150 meters from the
waste management unit boundary and
shall be located on land owned by the
owner or operator of the MSWLF. The
establishment of th& alternative
boundary shall be based on analysis
and consideration of at least the
following factors:
(1) The hydrogeologic characteristics
of the facility and surrounding land;
(2) The volume and physical and
chemical characteristics of the leachate;
(3) The quantity, quality, and direction
of flow of ground water;
(4) The proximity and withdrawal rate
of the ground-water users;
(5) The availability of alternative
drinking water supplies;
(6) The existing quality of the ground
water, including other sources of
contamination and their cumulative
impacts on the ground water;
(7} Public health, safety, and welfare
effects; and
(8) Practicable capability of the owner
or operator.
(e) Existing municipal solid waste
landfill units must be equipped at
closure with a final cover system that is
designed to prevent infiltration of liquid
through the cover and into the waste.
§§ 258.41-253.49 [Reserved]
Subpart IE—Ground-Water Monitoring
and Corrective Action
§ 258.50 AppHsabiJity,
(a) The requirements in this Part apply
to municipal solid waste landfill units,
except as provided in paragraph (b) of
this section.
(b) Ground-water monitoring
requirements under § 258.51 through
§ 258.55 of this Part will be suspended
for an MSWLF unit if the owner or
operator can demonstrate to the State
that there is no potential for migration of
hazardous constituents from that unit to
the uppermost aquifer during the active
life, including the closure period, of the
unit and during post-closure care. This
demonstration must be certified by a
qualified geologist or geotechnical
engineer, and must incorporate reliable
site-specific data. If detailed
hydrogeologic data are unavailable, the
owner or operator must provide an
adequate margin of safety in the
prediction of potential migration of
hazardous constituents by basing such
predictions on assumptions that
maximize the rate of hazardous
consitutent migration.
(c) Within 6 months of the effective
date of the rule, the State must specify a
schedule for, the owners or operators of
MSWLF units to comply with the
ground-water monitoring requirements
specified in §§258.51-258.55, This
schedule must be specified to ensure
that 25 percent of MSWLF units are in
compliance within 2 years of the
effective date of this rule; 50 percent
(50%) of landfill units are in compliance
within 3 years of the effective date of
this rule; 75 percent of the landfill units
are in compliance within 4 years of the
effective date of this rule; and all landfill
units are in compliance within 5 years of
the effective date of this rule. In setting
the compliance schedule, the State must
consider potential risks posed by the
MSWLF unit to human health and the
environment. The following factors
should be considered in determining
potential risk:
(l).Proximity of human and
environmental receptors; •
[2) Design of the landfill unit;
(3) Age of the landfill unit; and
(4) Resource value of the underlying
aquifer, including:
(i) Current and future uses;
(ii) Proximity and withdrawal rate of
users; and
(iii) Ground-water quality and
quantity.
(d] If the State does not set a schedule
for compliance as specified in paragraph
{c) of this Section, the following
compliance schedule shall apply:
(1) Existing landfill units less than 1
mile from a drinking water intake
(surface or subsurface) must be in
compliance with the ground-water
monitoring requirements specified in
§ § 258.51-258.55 within 3 years of the
effective date of this rule;
(2) Elxisting landfill units greater than
1 mile but less than 2 miles from a
drinking water intake (surface or
subsurface) must be in compliance with
the ground-water monitoring
requirementa specified in §J 258.51-
258.55 within 4 years of the effective
date o:f this rule;
(3) Existing landfill units greater than
2 mileti from a drinking water intake
(surface or subsurface) must be in
compliance with the ground-water
monitoringrequirements specified in
§§ 258:51-258.55 within 5 years .of the
effective date of this rule; and
(4) A new landfill unit must be in
compliance with the ground-water
monitoring requirements specified in
§ § 258.51-258.55 before waste can be
placed in the unit.
OB): Once established at a unit, ground-
water monitoring shall be conducted
throughout the active life and post-
closure care of that municipal solid
waste landfill unit as specified in
1258.31.
§258.51 Ground-water monitoring
systems.
(a) A ground-water monitoring, well
. system approved by the State must be
installed at the closest pacticable
distance from the, waste management
unit boundary or the alternative
boundary specified by the State under
§ 258.40. Where subsurface conditions
cause hazardous constituents to migrate
horizontally past the boundary specified
under this paragraph before descending
to the uppermost aquifer, the State can
designate another appropriate .
downgradient location for.the ground-
water monitoring wells.
(b) A ground-water monitoring system
must consist of a sufficient number of
wells, installed at appropriate locations
and depths, to yield ground-water
sampleis from the uppermost aquifer
that:.
(1) Represent the quality of
background ground water that has not
been affected by leakage from a landfill
unit; and
(2) Represent the quality of ground
water passing the locations, specified
under paragraph (a) of this section.
(c) If approved by the State, separate
ground-water monitoring systems are
not required for each landfill unit when
the facility has several landfill units,
provided the multi-unit ground-water
monitoring system will be as protective
of human health and the environment as
individual monitoring systems for each
unit. ;
(d) Monitoring wells must be cased in
a manner that maintains the integrity of
the monitoring well bore hole. This
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83412
Federal Register / Vol. 53, No. 168, Tuesday, August 30, 1988 / Proposed Rules
casing must be screened or perforated
and packed with gravel or sand, where
necessary, to enable collection of
ground-water samples. The annular
space (i.e., the space between the bore
hole and well casing) above the
sampling depth must be sealed to
prevent contamination of samples and
the ground water.
(1) The design, installation,
development, and decommission of any
monitoring wells, piezometers and other
measurement, sampling, and analytical
devices must be documented in the
operating record; and
(2) The monitoring wells, piezometers,
and other measurement, sampling, and
analytical devices must be operated and
maintained so that they perform to
design specifications throughout the life
of the monitoring program.
(e) The number, spacing, and depths
of monitoring systems shall be proposed
by the owner or operator and approved
by the State based upon site-specific
technical information that must be
developed by the owner or operator and
must include thorough characterization
of:
(1) Aquifer thickness, flow rate, and
flow direction; and
(2) Saturated and unsaturated
geologic units and fill materials
overlying the uppermost aquifer,
including, but not limited to:
thicknesses, stratigraphy, lithology,
hydraulic conductivities, and porosities.
§25832 Determination of ground-water
trigger level.
(a) The State must establish, before a
Phase I monitoring program is initiated,
ground-water trigger levels that are
protective of human health and the
environment for all Appendix n
constituents.
(b) The levels are to be specified by
the State as:
(1) Maximum Contaminant Level
(MCL) promulgated under § 1412 of the
Safe Drinking Water Act (codified)
under 40 CFR Part 141, Subpart B; or
(2) For constituents for which MCLs
have not been promulgated, an
appropriate health-based level
established by the State that satisfies
the following criteria:
(1) The level is derived in a manner
consistent with Agency guidelines for
assessing the health risks of
environmental pollutants (51FR 33992,
34000,34014,34028);
(11) Is based on scientifically valid
studies conducted in accordance with
the Toxic Substances Control Act Good
Laboratory Practice Standards (40 CFR
Part 792) or equivalent;
(iii) For carcinogens, the level
represents a concentration associated
with an excess lifetime cancer risk level
(due to continuous lifetime exposure)
within the 1X10~* to 1X10~7 range; and
(iv) For systemic toxicants, the level
represents a concentration to which the
human population (including sensitive
subgroups) could be exposed to on a
daily basis that is likely to be without
appreciable risk of deleterious effects
during a lifetime.
[Noteto§258.52(b)(2)(iii):EPAi8 .
considering alternatives to the lxl0~4to
1X10"' risk range. The Agency specifically
requests comment on a fixed risk level of
1X1CT6 or an upper bound risk level of
IXIO"4 (with the States having discretion to
be more stringent) as alternatives to the
proposed risk range. A fixed risk level of
1X10" 5 would provide a uniform level of
protection across all States. On the other
hand, setting an upper bound risk level of
1X10~* would allow States greater flexibility
in establishing more stringent risk levels
based on site specific conditions].
(3) For constituents for which no
health-based level is. available that
meets the criteria hi § 258.52(a)(l) or (2)
the State may establish a trigger level
that shall be:
(i) An indicator for protection of
human health and the environment,
using the exposure assumptions
specified under § 258.52(a)(2), or
'(ii) The background concentration.
(4) For constituents for which the
background level is higher than health-
based levels established under
§ 258.52(b)(l)-(3), the trigger level shall
be the background concentration.
§ 258.53 Ground-water sampling and
analysis requirements.
(a) The ground-water monitoring
program must include consistent
sampling and analysis procedures that
are designed to ensure monitoring
results that provide an accurate
representation of ground-water quality
at the background and downgradient
wells installed in compliance with
§ 258.51(b) of this part. At a minimum,
the program must be documented in the.
operating record and must include
procedures and techniques for:
(1) Sample collection;
(2) Sample preservation and shipment;
(3) Analytical procedures;
(4) Cham of custody control; and
(5) Quality assurance and quality
control.
(b) The ground-water monitoring
program must include sampling and
analytical methods that are appropriate
for ground-water sampling and that
accurately measure hazardous
constituents and other monitoring
parameters in ground-water samples.
(c) The sampling procedures and
frequency must be protective of human
health and the environment. The
sampling requirement must ensure that
the statistical procedure used to
evaluate samples has an acceptably low
probability of failing to identify
contamination.
(d) Ground-water elevations must be
measured in each well immediately
prior to sampling.The owner or operator
must determine the rate and direction of
ground-water flow in the uppermost;
aquifer each time ground-water gradient
changes as indicated by previous
sampling period elevation mesurements.
(e) The owner or operator must
establish background ground-water
quality on a hydraulically upgradient
well(s) for each of the monitoring
parameters or constituents required in
the particular ground/water monitoring
program that applies to the municipal
solid waste landfill unit, as determined
under § 258.54(a), or § 258.55[a) of this
part. The minimum number of samples
used to establish background ground-
water quality must be consistent with
the appropriate statistical procedures
determined pursuant to paragraph (h) of
this section.
(f) Background ground-water quality
at existing units may be based on
sampling of wells that are not
upgradient from the waste management
area where:
(1) Hydrogeologic conditions do not
allow the owner or operator to
determine what wells are upgradient;
and
(2) Sampling at other wells will
provide an indication of background
ground-water quality that is as
representative or more representative
than that provided by upgradient wells.
(g) The State may determine alternate,
background ground-water quality on a
site-specific basis if true background
ground-water quality cannot be detected
on site. The alternate background
ground-water quality should be based
on monitoring data from the uppermost
aquifer that is available to the State.
(h) Statistical procedures are as
• follows:
(1) Ground-water monitoring data for
each phase of the monitoring programs
of § § 258.54, 258.55 and any other
applicable section of this rule will be
collected from background wells (except
as allowed in § 258.53(g)), and at
monitoring wells as specified pursuant
to § 258.53(a). Based on the site-specific
conditions identified in § 258.54(c), the
owner or operator must select the
appropriate statistical procedure to
determine if a statistically significant
increase over background value for each
parameter or constituent has occurred.
(2) The owner or operator must
employ one of the following statistical
-------
procedures, in combination with the
designated sampling requirement, to
determine a statistically significant
increase:
p) A parametric analysis of variance
(ANOVA) followed by multiple
comparisons procedures to identify
. statistically, significant evidence of
contamination. The procedure must
include estimation and testing of the
contrasts between each downgradient
well's mean and the background mean
- level for each constituent;
pi) "An analysis of variance based on
ranks followed by multiple comparisons
procedures to identify statistically
significant evidence of contamination.
The procedure must include estimation
and testing of the contrasts between
each downgradient well's mean and the
background mean level for each
constituent;
pii) Tolerance or prediction interval
procedure in which a tolerance interval.
for each constituent is established from
the distribution of the background data,
and the level of each constituent in each
downgradient well is compared to the
upper tolerance or prediction limit;
, pv) A control chart approach that
gives control limits for each constituent;
and
(v) Another statistical test procedure
that is protective of human health and
the environment and meets the ground-
water protection standard of § 258.52(b).
(3) The State may establish an
alternative sampling procedure and
statistical test for any of the
constituents listed in Appendix II or
parameters listed in § 258.54(b), as
required to protect human health and
the environment. Factors to consider for
establishing this alternative statistical
procedure include:
p) If the distributions for different
constituents differ, more than one
procedure may be needed. The owner or
operator must show that .the normal
distribution is not appropriate if.using a
nonparametric or-other methodology not
requiring an assumption of normality.
For any statistic not based on a normal
distribution, a goodness of fit test shall
be conducted to demonstrate that the
normal distribution is not appropriate.
Other tests shall be conducted to
demonstrate that the assumptions of the
statistic or distribution are not grossly
isolated; :
pi) Each parameter or constituent is to
be tested for separately. Each time that
a test is done, the test for individual
constituents shall be done at a type I
error level or less than 0.01. A multiple
comparison procedure may be used at a
type I experiment-wide error rate no
less than 0.05. The owner or operator
must evaluate the ability of the method;
to detect contamination that is actually^
present and may be required to increase
the sample size to achieve an acceptable
error level.
pii) The monitoring well system
should be consistent with § 258.51. The
owner or operator must ensure that the
number, location, and depth of
monitoring wells will detect hazardous
constituents that migrate from ths
municipal solid waste landfill unit;
pv) The statistical procedure .should
be appropriate for the behavior of the
parameters or constituents involved. It
should include methods for handling.
data below the limit of detection. The
owner or operator should evaluate
different ways of dealing with values
below the limit of detection and choose
the one that is most protective of human
health and the environment. In cases
where there is a high proportion of
values below limits of detection, the
owner or operator may demonstrate that
an alternative procedure is more
appropriate; and
(v) The statistical procedure used
should account for seasonal and spatial
variability and temporal correlation.
(4) If contamination is detected by any
of the statistical tests, and the State or
the owner or operator suspects that
detection is an artifact caused by some
feature of the data other than
contamination, the State may specify
that statistical tests of trend, seasonal
variation, autocorrelation, or othsr
interfering aspects of the data be done
to establish whether the significant
result is indicative of detection of
contamination or resulted from natural
variation.
p) The owner or operator must
determine whether or not there is a
statistically significant increase (or
decrease, in the case of Phase I) over
background values for each parameter
or constituent required in the particular
ground-water monitoring program that
applies to the landfill unit as
determined under §§ 258.54(a) or
258.55(a) of this part. The owner or
operator must make these statistical
determinations each time he assesses
ground-water quality at the boundary
designated under § 258.40 of this part.
(A) In determining whether a
statistically significant increase or
decrease has occurred, the owner or
operator must compare the ground-
water quality of each parameter or
constituent at each monitoring well
designated pursuant to § 258.51 to the
background value of that parameter or
constituent, according to the statistical
procedures specified under paragraph
(h) of this section.
(B) Within a reasonable time period
after completing sampling (as
determined by the State), the owner or
operator must determine whether there
has been a statistically significant
increase1 or decrease over background at
each monitoring well.
§ 253.E4 Phass I monitoring program.
(a) Phiase I monitoring is required at
municipal solid waste landfill units
except'as otherwise provided in
§§ 258.53 and 258.58 of this Part.
(b) At a minimum, a Phase I
monitoring program must include the
following monitoring parameters or
constituents: •
(1) Ammonia (as N)
(2) Bicarbonate (HCO3j
(3) Calcium
(4) Chloride
(5) Iron !i .
(6) Magnesium
(7) Manganese, dissolved
(8) Nitrate (as N) '
(9) Potassium
(10) Sodium
(11) Sulfate (SO4)
(12) Chemical Oxygen Demand (COD)
(13) Total Dissolved Solids (TDS)
(14) Total Organic Carbon (TQC)
(15) pH i
(16) Arsenic
[!?)• Barium,"
(18) Cadmium
(19) Chrqmin
(20) Cyanide
(21) Lead
(22) Mercury .
(23) Selenium .
(24) Silver ..-.,-
(25) The volatile organic compounds
(VOCs) listed in Appendix I of this
part. ;
(c) The: State must determine an
appropriate monitoring frequency on a
site-specific basis by considering aquifer
flow rate and resource value of the
ground water. The minimum monitoring
frequency for all parameters specified in
paragraph (b) of this section is
semiannual except during the post-
closure care when minimum monitoring'
frequency shall be determined by the
State on a site-specific basis.
(d) If the owner or operator
determines, pursuant to § 258.53(h) of
this part, that there is a statistically
significant increase or decrease over
background for. two or more of
parameters (1) to (15) specified in
paragraph (b) of this section, at any
monitoring well at the boundary
specified imder § 258.51(a), or a
statistically significant increase over
background for any one or more of
parameters (16) to (24) specified in
paragraph (b) of this section or the
VOCs listed in Appendix I, at any
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83414
Federal Register / Vol.-53, No.^168, Tuesday, August 30, 1&88 / Proposed fades
monitoring well at the boundary
spenlfied under § 258.51(a), (s)he:
(1) Must notify the State within 14
days of this finding. The notification
must indicate what Phase I parameters
have shown statistically significant
changes from background levels;
(2) Must establish a Phaae U
monitoring program meeting the
requirements of § 258.55 this part within
a reasonable time period as determined
by the State; and
(3) May demonstrate that a source
other than a municipal solid waste
landfill unit cause the contamination or
that the contamination resulted from
error in sampling, analysis, or
evaluation. While the owner or operator
may make a demonstration under this
paragraph In lieu of establishing a Phase
II monitoring program, the owner or
operator is not relieved of the
requirement to establish a Phase n
monitoring program within a reasonable
time period unless the demonstration
made under this paragraph successfully
shows that a source other than the
municipal solid waste landfill unit
caused the change or that the change
resulted from an error in sampling,
analysis, or evaluation. In making a
demonstration under this paragraph, the
owner or operator must:
(i) Notify the State in writing within 7
days of determining statistically
significant evidence of contamination
that (s)he intends to make a
demonstration under this paragraph;
(ii) Within 90 days, or an alternative
time period approved by the State,
submit to the State a report that
demonstrates that a source other than a
municipal solid waste landfill unit
caused the contamination or that the
contamination resulted from error in
sampling, analysis, or evaluation; and
0H) Continue to monitor in
accordance with the Phase I monitoring
program.
§ 258.55 Phase II monitoring program.
(a) Phase n monitoring is required
whenever statistically significant
increases or decreases over background
have been detected for two or more of
parameters (1) to (15) specified under
§ 258.54(b); or whenever statistically
significant increases over background
have been detected for one or more of
parameters (16) to (24) specified under
§ 258.54(b), or the VOCa listed hi
Appendix I; or the State determines,
pursuant to § 258.58, that a corrective
action remedy has been completed.
(b) At a minimum, Phase n monitoring
program must include the constituents in
Appendix II of this part
(c) Within 90 days of triggering a
Phase II monitoring program or an
alternative time period approved by the
State, the owner or operator must
sample the ground water in all
monitoring wells identified pursuant to
§ 258.51 of this part and analyze those
samples for all constituents identified in
Appendix II of this part.
(d) If Appendix II constituents are not
detected in response to paragraph (c),
the State shall specify an appropriate
frequency for repeated sampling and
analysis for Appedix II constituents
during the active life, closure, and post-
closure care of the unit. The following
factors should be considered by the
State when setting an appropriate
frequency for a full Appendix II
analysis:
(1) Lithology of the aquifer and
unsaturated zone;
(2) Hydraulic conductivity of the
aquifer and unsaturated zone;
(3) Aquifer flow velocities;
(4) Minimum distance between
upgradient edge of unit and
downgradient monitoring well screen
(minimum distance of travel); and
(5) Nature of any constituents
detected in response to this section.
(e) If, after conducting Phase II
monitoring or an appropriate time period
approved by the State; the owner or
operator determines that there has not
been a statistically significant increase
over background of parameters or
.constituent specified pursuant to
§ 258.55(b) of this part at any monitoring
well at the boundary specified under
§ 258.51(a), that unit may return to Phase
I monitoring. The following factors
should be considered by the State when
determining an appropriate time period
for sampling before allowing a unit to
return to Phase I monitoring:
(1) Lithology of the aquifer and
unsaturated zone;
(2) Hydraulic conductivity of the
aquifer and unsaturated zone;
(3) Aquifer flow velocities; and
(4) Maximum distance between
upgradient edge of unit and down-
gradient monitoring well screen
(potential maximum distance of travel).
(f) If any Appendix II constituents are
detected at statistically significant
levels above background response to (c)
or (d) of this section, the owner or
operator must:
(1) Notify the State hi writing within
14 days, or an alternative time period
approved by the State, which Appendix
n constituents have been detected at
statistically significant levels above
background; and
(2) Within 90 days, and on a quarterly
basis thereafter during the active life
and closure of the unit, resample all
wells and conduct analyses for those
constituents in Appendix II of this part
that are determined to be present at
levels above background concentrations
at the boundary specified under
§ 258.51(a) of this part.
(3) The State shall determine an
appropriate minimum monitoring
frequency for these Appendix II
constituents during the post-closure
period. The following factors should be
considered by the State when setting a
minimum monitoring frequency:
(i) Lithology of .the aquifer and
unsaturated zone;
(ii) Hydraulic conductivity of aquifer
and .unsaturated zone;
(iii) Aquifer flow velocities;
(iv) Minimum distance between
upgradient edge of unit and
downgradient monitoring well screen
(minimum distance of travel); and
(v) Nature of the constituents detected
in response to this section.
(g) If any Appendix II parameters or
constituents are identified under
paragraph (d) of this section that had
not been identified, previously under (c)
or (f)(2) of this section, the owner or
operator must, within 14 days, submit to
the State a report on the concentration
of any Appendix II constituents detected
at statistically significant levels above
background concentrations.
(h) If any Appendix II constituent is
detected at statistically significant
levels above the ground-water trigger
level established under § 258.52 of this
section, the owner or operator:
(1) Must notify the State of this finding
in writing within 14 days. The
notification must indicate what Phase II
parameters or constituents have
exceeded the ground-water trigger level;
(2) Must meet the requirements of
§ 258.56 of this part within a time period
determined by the State; and
(3) Must continue to monitor in
accordance with the Phase II monitoring
, program established under this section;
or
(4) May demonstrate that a source
other than a municipal solid waste
landfill unit caused the contamination,
or that the increase resulted from error
in sampling, analysis, or evaluation.
While the owner or operator may make
a demonstration under this paragraph in
lieu of establishing a corrective action
program, (s)he is not relieved of the
requirement to establish a corrective
action program within a reasonable time
period unless the demonstration made .
under this paragraph successfully shows
that a source other than the municipal
solid waste landfill unit caused the
increase, or that the increase resulted
from an error in sampling; analysis, or
evaluation. In making a demonstration
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Fedefal Register / Vpl. 53, No. 168. Tuesday.'Augtist 30, 1986 /.••Proposed-'Roles
33415
u -ier this paragraph, the owner or
operator must:
(i) Notify the State in writing within 7
days of determining statistically
, significant evidence of contamination
that (s)he intends to make a
demonstration under this paragraph;
(ii) Within 90 days, or an alternate
time period approved by the State,
submit to the State a report that
demonstrates that a source other than a
municipal solid waste landfill unit
caused the contamination or that the
increase resulted from error in sampling,
•. analysis, or evaluation; and
(iii) Continue to monitor in
accordance with the Phase II monitoring
program. ;
§253.5@ Assessment of corrective
measures. ,
(a) An assessment must be conducted
by the owner or operator when any of
the constituents listed in Appendix n
has been detected at a statistically
significant level exceeding the ground-
water trigger levels defined under
§ 258.52 of this part during the Phase H
monitoring program.
(b) The owner or operator must
continue to monitor in accordance with
the Phase II monitoring program. The'
State may require the owner or operator
to conduct additional monitoring in
order to characterize the nature and
extent of the plume.
(c) The State-shall specify the scope of
the assessment, which slay include the
following:
(1) Assessment of the effectiveness of
potential corrective measures in meeting
all of the requirements and objectives of
the remedy as described under § 258.57;
(2) Evaluation of performance,
reliability, ease of implementation, and
potential impacts of appropriate
potential remedies, including safety
impacts, cross-media impacts, and
control of exposure to any residual
contamination;
(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 that may substantially
affect implementation of the remedy(s);
and
(6) Evaluation of public acceptability.
(d) The State may require the owner
or operator 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 State's
judgment, achieve the standards for
remedies specified in § 258.57.
(e) The owner or operator shall submit
a report to the State on the remedies
evaluated pursuant to paragraphs (a)-
[d). The State shall then select a remedy
based on the criteria described in
§ 258.57.
(f} If at any time during the
assessment described under paragraphs
(a)-(e} of this section the State
determines that the facility poses a
threat to human health or the
environment, the State may require the
owner or operator to implement
measures defined under § 258.58(a)(3)
and/or (a)(4) to protect human health
and the environment.
§ 258.57 Selection of remedy and
establishment of ground-water protection
standard.
(a) Based on the results of the
corrective measure study conducted
under § 258.58, the State must select a
remedy that, at a minimum, meets the
standards listed in paragraph (b) below.
(b} Remedies must:
(1) Be protective of human health and
the environment;
(2) Attain the ground-water protection
standard as specified pursuant to
paragraphs (e) and (f) of this section;
(3) Control the source(s) of releases so
as to reduce or eliminate, to the
maximum extent practicable, further
releases of Appendix II-constituents into
the environment that may pose a threat
to human health or the environment; and
(4) Comply with standards for
management of wastes as specified hi
§258.58(d).
[c) In selecting a remedy that meets
the standards of § 258.57(b), the State,
as appropriate, shall consider the
following evaluation factors:
(1) Any potential remedy(s) shall be
assessed for the long- and short-term
effectiveness and protectiveness it
affords, along with the degree of
certainty that the remedy will provide
successful. Factors to be considered
include:
(i) Magnitude of reduction of existing
risks;
(ii) Magnitude of residual risks in
terms of likelihood of further releases
due to waste remaining following
implementation of a remedy;
[iii) The type and degree of long-term
management required, including '
monitoring, operation, and maintenance;
(iv) 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;
fv) Time until full protection is
achieved;
(vi) Potential for exposure of humans
and environmental receptors to
remaining wastes, considering the
potential threat to human health and the
enviroriment associated with
excavation, transportation, redisposal,
or containment; -
(vii) Long-term reliability of the
engineering and institutional controls;
and - •;.-...-•-.'
(viii) Potential need for replacement of
the remedy. ^ , •
(2) Effectiveness of the remedy in
controlling the source to reduce further
releaseu. The following factors should
be considered:
(i) The extent to which containment
practices will reduce further releases;
(ii) The extent to which treatment
technologies may be used.
(3) The ease or difficulty of
implementing a potential remedy(s)
shall 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; and
(v) Available capacity and location of
needed treatment, storage, and disposal
services.
(4) Practicable capability of the owner
or operator including a consideration of
the technical and economic capability. -
(5) The degree to which community
concerns are addressed by a potential
remedy(s) shall be assessed.
(d) The State shall specify as part of
the selected remedy a schedule(s) for
initiating and completing remedial
activitieis. The State 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 ground-water protection standards
established under § 258.57(e) and other
objectives of the remedy;
(3) Availability of treatment or
disposal capacity for wastes, managed
during implementation of the remedy;
(4) Desiirability of utilizing
technoloigies that are not currently
available, but which may offer
significant advantages over already
available technologies in terms of
-------
,341G
Federal Register / Vol. 53. No. 168, Tuesday, August 30, 1988 / Proposed Rtilg3_
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; and
(6) Resource value of the aquifer
including:
(i) Current and future uses;
(11) Proximity and withdrawal rate of
users;
(Hi) Ground-water quantity and
quality;
(iv) The potential damage to wildlife,
crops, vegetation, and physical
structures caused by exposure to waste
constituent;
(v) The hydrogeologic characteristic of
the facility and surrounding land;
(vi) Ground-water removal and
treatment costs; and
{vii) The cost and availability of
alternative water supplies.
(7) Practicable capability of the owner
or operator.
(8) Other relevant factors.
(e) The State shall specify
concentration levels for each Appendix
n constituent detected in the ground
water above trigger levels that the
remedy must achieve. Such ground-
water protection standards (GWPSs)
will be established by the State as
follows:
(1) The atandard(s) shall be
concentration levels in the ground water
that protect human health and the
environment;
(2) Unless another level is deemed
necessary to protect environmental
receptors, standards shall be
established as follows:
(i) For known or suspected
carcinogens, standards shall be
established at concentration levels that
represent an excess upper bound
lifetime risk to an individual of between
1X10~4 and 1X10'7, and
(ii) For nystemic toxicants, standards
shall represent concentration levels to
which the human population (including
sensitive uubgroups) could be exposed
on a daily basis without appreciable risk
of deleterious effect during a lifetime.
[Note to § 2S8.57(e)(2)(i): EPA Is
considering alternatives to the 1X10'* to
IXlfT'risk range. The Agency specifically
requests comment on a fixed risk level of
1X10~* or an upper bound risk level of
1X10~* (with the States having discretion to
be more stringent) as alternatives to the
proposed risk range. A fixed risk level of
1X10~* would provide a uniform level of
protection across all States. On the other
hand, setting an upper bound risk level of
1X10"4 would allow States greater flexibility
In establishing more stringent risk levels
baaed on site specific conditions.]
(3) In establishing ground-water
protection standards that meet the
requirements of § 258.57(e) (i) and (ii),
above, the State may consider the
following:
(i) Multiple contaminants in the
ground water;
(ii) Exposure threats to sensitive
environmental receptors;
(iii) Other site-specific exposure or
potential exposure to ground water; and
(iv) The reliability, effectiveness,
practicability, or other relevant factors
of the remedy.
(4) For ground water that is a current
or potential source of drinking water,
the State shall consider maximum
contaminant levels promulgated under
the Safe Drinking Water Act in
establishing ground-water protection
standards; and
(5) If the owner or operator can
demonstrate to the State that an
Appendix II constituent already is
present in the ground water at a
background level, then the GWPS will
not be set below background levels
unless the State determines that:
(i) Cleanup to levels below
background levels is necessary to
protect human health and the
environment; and
(ii) Such cleanup is in connection with
an area-wide remedial action under
other authorities.
(f) The State may determine that
remediation of a release of an Appendix
n constituent from a municipal solid
waste landfill is not necessary if the
owner or operator demonstrates to the
State's satisfaction that:
(1) The ground water also is
contaminated by substances that have
originated from a source other than a
municipal solid waste landfill unit and
those substances are present hi
concentrations such that cleanup of the
release from the municipal solid waste
landfill unit would provide no significant
reduction in risk to actual or potential
receptors; or
(2) The constituent(s) is present in
ground water that:
(i) Is not a current or potential source
of drinking water; and
(ii) Is not hydraulically connected
with waters to which the hazardous
constituents are migrating or are likely
to migrate in a concentration(s) that
represents a statistically significant
increase over background
concentrations; or
(3) Remediation of the release(s) is
technically impracticable or results in
unacceptable cross-media impacts.
(g) A determination by the State
pursuant to subparagraph (2) above
shall not affect the authority of the State
to require the owner or operator to
undertake source control measures or
other measures that may be necessary
to eliminate or minimize further releases
to the ground water, to prevent exposure
to the ground water, or to remediate the
ground water to concentrations that are
technically practicable and significantly
reduce threats to human health or the
environment.
(h) The State shall specify in the
remedy requirements for achieving
compliance with the ground-water
protection standards established under
§ 258.57(e) as follows:
(1) The ground-water protection
standard shall be achieved at all points
within the plume of contamination that
lie beyond the ground-water monitoring
well system established under
§258.51(a).
(2) The State shall specify in the
remedy the length of time during'which
the owner or operator must, in order to
achieve compliance with a ground-water
protection standard, demonstrate that
concentrations of Appendix II
constituents have not exceeded the
standard(s). Factors that may be
considered by the State in determining
these timing requirements include:
(i) Extent and concentration of the
release^s);
(ii) Behavior characteristics of the
hazardous constituents in the ground
water;
(iii) Accuracy of monitoring or
modeling techniques, including any
seasonal, meteorological; or other
environmental variabilities that may
affect the accuracy; and
(iv) Characteristics of the ground
water.
§ 258.58 implementation of the corrective
action program.
(a) If any constituent is detected at
statistically significant levels above the
ground-water protection standard
established under § 258.57(e), the owner
or operator must:
(1) Establish and implement a
corrective action ground-water
monitoring program that must:
(i) At a minimum, meet the
requirements of a Phase II monitoring .
program under § 258.54;
(ii) Demonstrate the effectiveness of
the corrective action remedy; and
(iii) Demonstrate compliance with
ground-water protection standard
pursuant to § 258.57(f).
(2) Implement the corrective action
remedy selected under § 258.57;
(3) Notify all persons who own the
land or reside on the land that directly
overlies any part of the plume of
contamination; and
(4) Take any interim measures
deemed necessary by the State to
ensure the protection of human health
-------
/ Vol. 53, No. 168, Tuesday, August 30, 1988 /Proposed Rules
33417
and ihe environment. Interim measures
should, to the extent practicable, be
consistent with the objectives of and
contribute to the performance of any
remedy that may be required pursuant
to § 258.57. The following factors may be
considered by the State in determining
whether interim measures are
-necessary:
p) Time required to develop and
implement a final remedy;
(ii) Actual or potential'exposure of
nearby populations or environmental
receptors to hazardous constituents;
(iii) Actual or potential contamination
of drinking water supplies or sensitive
ecosystems;
(iv) Further degradation of the ground
water that may occur if remedial action
is not initiated expeditiously;
(v) Weather conditions that may
cause hazardous constituents to migrate
or be released;
(vi) Risks of fire or explosion, or
potential for exposure to hazardous
constituents as a result of an accident or
failure of a container or handling
system; and
(vii) Other situations that may pose
threats to human health and the
environment.
(b) The State may determine, based
on information developed by the owner
or operator after implementation of the
remedy has begun or other information,
that compliance with a requirement(s)
for the remedy selected under § 258.57 is
not technically practicable. In making
such determinations, the State shall
consider:
(1) The owner or operator's efforts to
achieve compliance with the
requirement(s); and
(2) Whether other currently available
or new and innovative methods or
techniques could practicably achieve
compliance with the requirements.
(c) If the State determines that
compliance with a remedy requirement
Appendix II—Hazardous Constituents
is not technically practicable, the State
may require that the owner or operator:
(1) Implement alternate measures to
control exposure of humans or the.
environment to residual contamination,
as necessary to protect human health
and the environment; and
(2) Implement alternate measures for
control of the sources of contamination,
or for removal or decontamination of
equipment, units, devices, or structures
required to implement the remedy that
are:
(i) Technically practicable; and
(ii) Consistent with the overall
objective of the remedy.
(d) All solid wastes that are managed
pursuant to a remedy required under
§ 258.57, or an interim measure required
under § 258.58(a)(4), shall be managed in
a manner:
(1) That is, protective of human health
and the environment; and
(2) That complies with applicable
RCRA requirements.
(e) Remedies selected pursuant to
§ 258.57 shall be considered complete
when the State determines that:
(1) Compliance with the ground-water
protection standards established under
§ 258.57(e) have been achieved,
according to the requirements of
§ 258.57(f); and
(2) All actions required to complete
the remedy have been satisfied.
(f) Upon completion of the remedy, the
owner or operator shall submit to the
State a certification that the remedy has
been completed in accordance with the
requirements of § 258.58(e). The
certification must b& signed by the
owner or operator and by an
independent professional(s) skilled in
the appropriate technical disciplmefs).
(g) When, upon receipt of the
certification, and in consideration of any
other relevant information,; the State
determines that the corrective action
remedy has been completed in
accordance with the requirements under
paragraph (e) of this section, the State
shall release the permittee from1 the
requirements for financial, assurance for
corrective action under § 258.32.
§,253.59 [Reserved].
Appondix I—Volatile Organic:
Constituents for Ground-Water *1
Monitoring ' •
•**
Acetcine
Acrolein
Acrylonitrile
Benzeme
Bromochloromethane
Bromodichloromethane
cis-l,;i-Dichloropropene
T.rans-l,3-Dichloropropene
1,4-Difluorobenzene
Ethanol
Ethylbenzene
Ethyl methacrylate
4-Bromofluorobenzene
Bromoform
Bromomethane
2-Butanone (Methyl ethyl ketone)
Carbon disulfide
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane-
Chloroethane
2-Ghloroethyl vinyl ether - -
Chloroform
Chloromethane
Dibromomethane
l,4-Dichloro-2-butane
Dichlorodifluoromethane
1,1-Diohloroethane
1,2-Dichloroethane
2-Hexanone
lodomethane ,
Methylene chloride
4-Methyl-2-pentanone
1,1-Diohloroethene
trans-:i,2-Dichloroethene
Styrer.e
l,l,2,a-Tetrachloroetfiane
Toluene
1,1,1-lrichloroethane
1,1,2-Trichloroethane
Trichloroeihene
Trichlbrofluoromethane
1,2,3-lrichloropropane
Vinyl acetate
Vinyl chloride
Xylen«
Systematic name
Acenaphthylene
Acenaphthylene, 1,2-dihydro-
Acetamide, N-(4-ethoxphenyl)-H
Acetamide, N-9H-fluoren-2-yl
Acetic acid ethenyl ester
Acetic acid (2,4-S-trichloro-phenoxy)-
Acetic acid (2,4-dichloro-phenoxy)-
Acetronitrile
Aluminum
Anthracene
Antimony
Aroclor 1016...:. „
Aroclor 1221
Aroclor 1232
Aroclor 1242
Aroclor 1248
Aroclor 1254
CASRN
206-96-B
83-32-9
62-44-2
53^96-3
106-05-4
93-76-5
94-75-7
75-05-8
7429-90-5
120-12-7
7440-36-0
12674-11-2
11104-28-2
11141-16-5
53469-21-9
12672-29-6
11097-69-1
, Common name
Acenaphthalene, .:
Acenaphthene.
Phenacetin.
2-Ac6tylaminofluorene.
Vinyl acetate.
2,4,5-T.
2,4-DichIorophenoxy-acetic s
Acetonitrile.
: Aluminum (total).
Anthracene;
: Antimony (total).
Aroclor 101 6.
Aroclor 1221.
Aroclor 1232.
Aroclor 1242.
Aroclor 1248.
Aroclor 1254.
•
-'_ ; ••••
cid. ?
-- ' . •->
-------
33418 Federal Register / Vol. 53, No. 168,' Tuesday, August 30, 1988 / Proposed Rules
• II Illll III lllll»ll»IIIHMMIIIlll^lllalillllllliM^^^ llllllllllllillllilMIIMMIIIIMIIIIIIIIlllM^
Systematic name
Aroetof 1260....™....,..,,..... -.» 11096-82-5
Arsarfc™.™.....™..,,.™.,.... ;. 7440-38-2
Barium... . . -. 7440-39-3
B«flzt«lanthracof», 7,12,-dlmethy!-. 57-97-6
Borectilfflceanthrytene, 1,2-dihydo-3-methyl - 56-49-5
Eksftz[»]acopb» 1.4-dfchtorc- ...... - 106-46-7
Baraooa 1,4-dtnitro- . . 100-25-4
Bonzana, 2-roolhyl-1.3-d!nitre- 606-20-2
Bonzana, chtoro , -.- - 108-90-7
Bwizond, dtmothyt- —. ^ 1330-20-7
Bonjiino, othonyl- 100-42-5
Borijona, ott^l- ..,...„.............._............„... 100-41 -4
Bonztna, hoxachtoro- n.™-.™ —™ .118-74-1
Benzene, malhyl 106-88-3
Benzono, nitro-. „ „ _ 96-95-3
Bonz&no, p€fitacWofo- *.»...«. « 608-93-5
B«mzone, ponladitofonitro- , — 82-68-8
Bcnamonootic add, 4-chtoro-a-(4-chlofophenyl)-a-hydroxy-, ethyl ester— 510-15-6
1,2.8«nz«ned!cart)0xylto add, b!s{2-ethyihexyl)ester 117-81-7
1,2.Benzenod(carboxyfic add, buy phenylmethyl ester. 85-68-7
f ,2-BenzwxKftairboxyBc add, dttiutyl oster. 84-74-2
1^-B«nzonadtearboxylIo add, diethyi ester. 84-66-2
1^'BofaanadicffltboxyBc add, dimethyl ester 131-11-3
1,2-Beretoo®dtearboxyPc add, dioctyl estor..— _ ~ 117-84-0
LS-Boraeoedfol...... ™™ .v... 106-46-3
B«nier«K>U»ar«min«, a, a-dfnwthyl-...—..— •• • 122-09-8
...»....».«..«.» 100-51-8
106-98-5
LS-Benodtoxoto. 5-<1-pfOpenyi)-.— 120-58-1
1,3.B«n20dlQxo!e,5-{2^5fOf>enyl)- ~ 94-59-7
BoraotMlluoranthon* '. 207-08-9
Bsnzoto add.........:....... ™ ; 65-85-0
BanzotfsOpontapJione™ 189-55-9
....- 191-24-2
«......! 50-32-8
B«f>IfiUm......-..~.~-.......™...-.~. .« 7440-41-7
l.l'-BlphontyiW-diamine. 3.3'-dtchk>ro- ...1...... 91-94-1
l.l'-BiphontyO-M'-diamlna, 3.3'-ditnothoxy- 119-90-4
1.V-Bij^en[yil-4,4'-dlainin9, W-dlmothyl- 119-93-7
1,1'-BtphonylC-4-amln«—. „ 92-67-1
l,1'.Biphenylt-4-4-amin9 , „ „ 92-87-5
1.3-BuWdtor*. 1,1,2.3,4.4-hexaditoro-.— 87-68-3
1^-ButacSono, 2-chtoro- 126-99-8
1-Btrt«n«m)o«, N-butyt-N-nltroso- .-. 924-16-3
2 Bttanono .„........,_........,....................... - 78-93-3
2-Bulone, 1.4^Sch!oro-, (E)- 110-57-6
Cadmium.™™..™,...... ~ ~ 7440-43-9
Catektm ..._.....„...,...... « - 7440-70-2
Cartiondlsuffids.. n....,..™m..™._ ™.. 75-15-0
Chromium.,.,...,, -., 7440-47-3
ChcyMTW..... 218-01-9
Cobalt . „ «. ... ,„.. - « - 7440-48-4
Copp«f ... 7440-50-8
CyarWa™...,.™™.......»™ ~ 57-12-5
2,5-Cydohixadfon0-1,4 diona _ .".. 106-51-4
, 1l2,3,4,5,6-hexachlofO-(1a,2a,3B,4a,5B,6B)- 319-84-6
CASRN
Common name
Aroclor 1260.
Arsenic (total).
Barium total).
7,i2-Dimethylbenzi:a] anthracsi
3-Meihylcholanthrene.
3enzo[b]fluoranthene.
3snzolb3fluoranthena.
'ronamide.
BenxCa] antiiracerie.
Aniline.
5-Nitro-o-toluidine.
2-Nitroaniline. •
3-Nitroaniline.
a^Jhloroaniline.
swiitroaniline.
4,4'-Methy!anabis (2-chloroaniline).
N-Nitrosodiphenylmamine.
Diphenylamine.
D-Dimethylamino-azobenzena.
Benzene. '
4-Bromophenyl phenyl ether.
4-Chlorophenyl pheny] ether.
2.4-Dinitrotoluene.
DDT.
Methoxychlor.
ODD.
DDE.
o-Dichlorobenzene.
1,2,4-trichlorobenzene.
1,2,4,5-Tetrachloro-benzene.
M-Dichlorobenzena.
p-Dichlorobenzene.
meta-Dinitrobenzene.
2,6-Dinitrotcluene.
Chlorobenzene.
Xylene (total).
Styrene.
Ethyl benzene.
Hexachlorobenzene.
Toluene.
Nitrobenzene.
Pentachlorobenzene.
Pentachloronitrobenzene.
Chlorobenzilate.
Bis(2-ethylhexyl) phthalate.
Butyl benzyl phthalate.
Di-n-butyl phthalate.
Diethyi phthalate.
Dimethyl phthalate.
Di-n-octyl phthalate.
Resorcinol.
alpha, alpha-Dimethyl-phenethylamlne.
Benzyl alcohol.
Benzeneihiol.
Isosafroje.
Safrole.
BenzotkJfluoranthene.
Benzole add.
DibenzoCa,i]pyrene.
Benzo(gW)perylane.
Benzo[a]pyrene. ,
Beryllium (total).
3,3'-Dichlorobenzidine.
3,3'-Dimethoxybsnzidine.
3,3'-Dimethylbenzidine.
4-Aminobiphenyl.
Benzidine.
Hexachorobutadiene.
2-Chloro-1,3-butadine.
N-Nitrosodi-n-butylamine.
Methyl ethyl ketone.
trans-1,4-Dichloro-2-butene.
Cadmium (total).
Calcium (total).
Carbon disulfide.
Chromium (total).
Chrysene.
Cobalt (total).
Copper (total).
Cyanide.
p-Benzcquinone.
a!pha-BHC.
-------
• Federal Register / Vol. 53, No. 168, Tuesday, August,30,, 1988 / Ifroposedt Rules',: 33419;
Systematic name.
Cyclohexane, 1,2,3,4,5,6-hexachloro-, (1a,2B,3a,4B,5a,6B)-
Cyclohexane, 1 ,2,3,4,5,6-hexachloro-, (1 a,2a,3a,4B,5a,6B)-
Cyclohexane, 1 ,2,3,4, 5,6-hexachloro-(1a,2a,3B,4a,5a,6B)-
2-Cyclohexen-1-one, 3,5,5-trimethyl <.............
1 ,3-Cyclopentadiene, 1 ,2,3,4,5,5-hexachloro-
Dibsnz[a,h]anthracene
Dlbenzo[b,eH1,4Moxin, 2,3,7,8-tetrachloro-
Dibenzo[b,def]chrysone .'.
Dibenzofuran
2,7:3,6-Dimethanonaphth [2,3-bloxirene, 3,4,5,6,9,9-hexachloro-
la,2,2a,3,6,6a,7,7a-octahydro, 1aa,2B,2aa,3B,6B,6aa,7B,7aa)-.
2,7:3,6-Dimethanonaphth [2,3-b]oxirene, 3,4,5,6,9,9-hexachloro-
ia,2,2a,3.6,6a,7,7a-octahydro. 1aa,2B,2aB,3a,6a,6aB,7B,7aa)-.
1 ,4:5,8-Dimethanonaphthalene, 1 ,2,3,4, 1 0,1 0-hexachloro-1 ,4,4a,5,8,8a-
hexahydro-, 1aa,4a,4aB,5a,8a,8aB)-.
1,4:5,8-Dimethanonaphthalene. 1,2,3,4,10,10-hexachforo-1,4,4a,5,8.8a-
hexahydra-, 1aa,4a,4aB,5B,8B,8aB)-.
Ethanamins, N-ethyl-N-nitroso
Ethanamine, N-methyl-N-nitroso-
Ethane, 1,1-diohloro-: .'.
Ethane, 1,1'-[methylenebis (oxy)]bis[2-chloro-
Ethane, 1,1'-oxybis[2-chloro-
Ethane, 1,1'-trichloro- ;
Ethane, 1,1,1,2-tetrachloro-
Ethane, 1,1,2-trichloro- .'.
Ethane, 1,1,2,2-tetrachloro-
Ethane, 1,2-dibromo-
Ethane, 1 ,2-dichloro-
Ethane, chloro-
Ethane, hexachloro- „.
Ethane, pentachloro-
1 ,2-Ethanediamine, N,N-dimethyl-N'-'2-pyridinyl-N'-(2-thienylmethyl)-
Ethanone, 1-phenyl-
Ethene, (2-chloroethoxy)- .". „
Ethene, 1 ,1-dichloro- „ „
Ethene, 1 ,2-dichloro- (E)- „ „ „.. _
Ethene, chloro- ;
Ethene, tetrachloro-
Ethene, trichloro-,
Fluoranthene
Fluoride
9H-Fluorene
2-Hexanone
Hydrazine, 1,2-diphenyl-
lndeno[1,2,3-cd]pyrene .......
Iron
Lead
Magnesium
Manganese
Mercury
Methanamine, N-methyl-N-nitroso
Methane, bromo-
Methane, bromodichloro-*
Methane, chloro-
Methane, dibromo-.... .-. .....; ... .
Methane, dibromochloro-
Methane, dichloro-
Methane, dichlorodifluoro-
Methane, iodo-
Methane, tetrachloro-
Methane, tribromo-
Methane, trichloro- , ;
Methane, trichlorofluoro-
Methanesulfonic acid, methyl ester
Methaneihiol, trichloro-
4,7-Methano-1 H-indene-1 ,2,4,5,6,7,8,8-octachloro-2,3,3a,4,7,7a-
hexahydro.
4,7-Methano-1H-indene-1,4,5,6,7.8,8-heptachloro-3a,4,7,7a-tetrahydro-
2,5-Methano-2H-indenoC1,2-b] oxirene, 2,3,4,5,6,7,7-heptachloro-
1 a, 1 b,5,5a,6,6a-hexahydro-, (1 aa,1 bB,2a,5a,5aB,6B,6aa).
6,9-Methano-2,4,3-benzo-dioxathiepin, 6,7,8,9,10,10-hexachloro-
1,5,5a,6,9,9a-hexahydro-, 3-oxide, (3a,5aB,6a,9a,9aB).
6,9-Methano-2,4,3-benzo-dioxathiepin, 6,7,8,9,10,10-
hexachloro,1,5,5a,6,9,9a-hexahydro-, 3-oxide, (3a,5aa,6B,9B,9aa).
1,3,4iMethano-2H-cyclobutal [cd3pentalen-2-ons, 1,1a,3,3a,4,5,5,5a,5b,6-
decachloro-octahydro-.
1 ,2,4-Methanocyclopenta[cd] pentalene-5-carboxaldehyde, 2,2a,3,3,4,7-
hexachloro-decahydro-, (1a,2B,2aB,4B,4aB,5B,6aB,6aB,7R*).
CAS RN'
319r^5-7
319-86-8
58-89-9
78-59-1
77-47-4
53-70-3
1746-01-6
189-64-0
132-64-9
60-57-1
72-20-8
309-00-2
465-73-6
123T-91-1
55-18-5
10595-95-6
75-34-3
11t-91-1
111-44-4
71-55-6
630-20-6
79-00-5
79-34-5
106-93-4
107-06-2
75-00-3
67-72-1
76-01-7
9T-80-5
98-86-2
110-75-8
75-35-4
156^60-5
75-01-4
• 12-7-T8-4
79-01-6
206-44-0
12984-48-8
86-73-7
591-78-6
1 22-66-7
193-39-5
7439-89 6
7439-92-1
7439-94-4
7439-96-5
7439-97-6
62 75-9
74-83-9
75-27-4
74-87-3
74-95-3
124-48-1
74-09-2
75-71-8
74-88-4
56-23-5
75-25-2
67^66-3
75-69-4
66-27-3
75-70-7
57-74-9
76-44-8
1024-57-3
959-96-8
" 33213^65-9
143-50-0
7421-93-4
: 59-89-2
Common name
beta-BHC ;
delta-BHC. :
gamma-BHC ' - '
Isophorone.
DibenzCa,h]anthracene. '•
2,3,7,8-Tetrachlbrodt benzo-p-dibxih* Rexachlbrodibenzo-p-dioxin* Pen-
tachlorodi-benzo-p-dioxins; Tetra-chlorodibenzo-p-dioxins.
Tetrachlorodi-benzofurans.
Dieldrin. ; .
\
Endrin. . '; .
Aldrin.
Isodrin.
N-Nitrosodiethylarnine '
1 1 1-TrichloroQthane '
1,1 1 2-Tetrachloroethane '
Hexachroroethane. ;
Methapyrilene.
Trichloroethene. •
Lead (total) "
Chlordsne. \
Heptachtor. ;
Heptachlor epoxide, "•
Endosulfan !. • i
Endosulfan II. - ' !
Kepone. i
Endrin aldehyde. , .
N-Nitrosomomholine. - j .
-------
33420
Federal Register / Vol..53, No..168, T^esdayrAugust 30, 1988 / Proposed Rules.
Systematic name
1 •NophSha'onamino.. ....... „„..,.„....,.„..„.„„
2 Naphlhalonamino, ........ „ „
Ncphlhalons ...................... „ „ „
NaphlhatofK}, 2-chtofo-.-..™ „
NiphthalMd, 2-mothyl-..™™
1,4-Naphthakmediona „ „ ;
Ntpfolhot1.2,3,4-denchrysene._
N$ck§]
O$rotum..*.».*».t.»«M*.*«..»« «
OX)fRf>0*~««»...« M»HM«R». M. .
2 PeoUnono, 4-mothyl-™.™....,........
PlwiftrUhrfHio ..«,., ..«» . .
Phwvol.™*™. . :.
Phenol. 2-{1-methyl0ropyO-4,6-dinitro.. .... .
PlKXiol, 2-chtora-......_...» „ „ „
Phanol, 2-methyl-.,.,.. . ..„.„ „ .
Phenol, 2-»nflthyM,6-dinitro-... -
Phenol, 2-nKro-™ » ..„ ~
Phonol, 2,2'-melhy!anebis [3.4,6-lrfchloro- . „
Phenol, 2,3 4,6-telraohloro-.... ....... . ...
Phono), 2,4-dfchtoro-... „
Phono), 2,4-dimetliyl............. ........... . „
Pbooo), 2,4-dinilro-... „ .„ ..;
Phenol. 2.4.5-tticrtloro- .„....„ :„.. ~
Phenol, 2,4,6-trichk>ro-.™™.™
Phonol, 2.6-diehtofo-
Phenol, 4-chtofo-3-mathyl-...™— ~ „
Pltoriol, 4-melhyl-,..«._...._ . „
Phanol, 4-nllro- „„.„„ ™_.
Pfot&nol, pon1dd>tofo- »«.«»......»
PbosphoKxSthtofc acid, 0.0-diethyl S-C(elhylthio) methyl] ester.
Phosphorodthtofe acid, 0,0-dtethyl S-[2-(ethylthio) ethyl] ester
PhosphofOtWote add, O.t4-C(d)meaiylamino) sulfonyl)] phenyl] 0,0-di-
mothyt oslor.
Phosphofothiok; acid, 0,0-dtelhyl 0-(4-nitrophenyl) ester.
Phosf^Ofothioic acid, 0,0-diethyl 0-pyrazinyl ester
Phosptiofolhiotc add, 0,0-dimethyl 0-(4-nitrophenyO ester
P^®rtdkKj, i-niuoso-.«« «.«...« ...«...»
pQlQ*ft$un) A
l-Propanam'tno, N-nitroso-N-propyl- „
Pcopaoft, 1^-d)bfon)o-3^hIofo».««.H.....n „. . ......
Proptm, 1,2,-mothyl-»..M».»t»..«....»..t....»
2*Propa(iorM) .»«»«..»...«........... »...,„.»....»...« -
2 •Pioponal ....................................... ..„
1-Propond, 1,1,2,3,3,3»lwxachloro-.
1-Propona, 1,3-dicWoro-, {E)-..™^ „ ,
1"PropflO9, 1,3-diditoro-, (Z)-... „
2-Proponontlilto, 2-methyl-.,........«.....,, _._ „
2-PropflKiunJUHa «« . .
2-Propenote add, 2-mathyl-, ethyl ester™
2^pfopof>oic field, 2*rriathyl-, mothyl ©stsr .. . .
2*Propcna1>ol.«..H»..».»».».».M «.. . .... ..
S-PropyrKl-ol™,...,™,..,.,..™.
PyT0rw .».»««...«.«,..... «...»..«..........«.«
pJrkSne,™ „
Pyrtdtoe 2-motrsyl-
Pyrkfew, 1-nitroso- «««.«.««..« »....»..»»»
Srtvef._..«.......... , . .
SocCum .„.„........,,,..... „
Suffida ... . . ..
Suffutous acid, 2-chtoroathyl 2-[4-(1,1-d!methylethyl) phenoxy)-1-methy-
telhy) ester.
TbsHkirn *«» * «
Thiodiphosphoric add (CHO)j P(S)liO). tetraethyl ester
Tin...,™. , ,.M. .._„ „ ...„
Tox@prK)f)Oi.».»»^.».n.««».»«..»....n..*»M......»
Vanffidiuni ,,„, M . ... . °.
Zwft
CASRN
134-32-7
91-59-8
91-20-3
91-58-7
91-57-6
130-15-4
192-65-4
7440-02-0
7440-04-2
75-21-8
108-10-1
85-01-8
108-95-2
88-85-7
95-57-8
95-48-7
534-52-1
88-75-5
70-30-4
58-90-2
120-83-2
105-67-9
51-28-5
95-95-4
88-06-2
87-65-0
59-50-7
106-44-5
100-02-7
87-86-5
298-02-2
298-04-4
52-85-7
56-38-2
297-97-2
298-00-0
100-75-4
7440-09-7
621-64-7
96-12-8
78-87-5
96-18-4
108-60-1
109-77-3
107-12-0
542-76-7
93-72-1
126-72-7
78-83-1
67-64-1
107-02-8
1888-71-7
10061-02-6
10061-01-5
107-05-1
126-98-7
107-13-1
97-63-2
80-62-6
107-18-6
107-19-7
129-00-0
110-86-1
109-06-8
930-55-2
7782-49-2
7440-22-4
7440-23-5
18496-25-8
140-57-8
7440-28-0
3689-24-5
7440-31-5
8001-35-2
7440-62-2
7440-66-6
Common name
1 -Naphthylamine.
2-Naphthylamine.
Naphthalene. ,
2-Chloronaphthalene. t
2-MethylnaphthaIene.
1 ,4-Naphthoquinone.
OibenzoCa,e]pyrene.
Nickel (total). .
Osmium (total).
Ethylene oxide.
4-Methyi-2-pentanons. -
Phenanthrene.
Phenol.,
2-sec-Butyl-4,6-dinitro-phenol. • • ^ -
2-Chlorophenoi.
ortho-Crosol '
4,6-Dinitro-o-creso!. ,
2-Nitrophenol. : .
Hexachlorophene.
2,3,4,6-Tetrachtorophenot.
2,4-Dichlorophenol.
2,4-Dimethylphenol.
2,4-Dinitrophenol.
2,4,5-Trichlorophenol.
2,4,6-Trichlorophenol.
2,6-Dichlorophenol.
p-Chloro-m-cresol.
para-Cresol.
4-Nitrophenol.
Pentachloraphenol.
Phorate.
Disulfoton. :
Famphur.
Parathion.
0,0-D!ethyl 0,2-pyrazinyl phosphorothioate.
Methyl parathion.
N-Nitrosopiperidine.
Potassium (total).
Di-n-propylnitrosamine.
1 2-Dibromo-3-chloro-propape. .
1 ,2-Dichloropropane.
Bis(2-ohloroisopropyl) ether.
Malononltrile.
Ethyl cyanide.
3-Ch!oropropionitrile. . .
Silvex
Tris(2,3-dibromopropyl) phosphate.
Acetone.
Acrolein.
Hexachloropropsne. a
trans-1 ,3-Dichloropropene.
cis-1 ,3-Dichloropropene.
3-Chloropropene. '
Methacrylonitrils.
Acrylonitrile.
Ethyl methacrylate.
Methyl methacrylate.
Allyl alcohol.
2-Propyn-1-ol.
Pyridine.
N-Nitrosopyrrolidine. -
Selenium (total).
Silver (total).
Sodium (total).
Sulfide.
Aramite. .,
Thallium (total).
Tetraethyldithiopyro-phosphate.
Tin (total).
Toxaphene.
Vanadium (total). ...
Zinc (total).
-------
, -
Federaf Register / Vol. 53, No7 168, Tuesday, August 30, 1988 / Proposed RuleV
33421
APPENDIX 111.—CARCINOGENIC SLOPE FACTORS (CSF's) AND REFERENCE DOSES (RfD's) FOR SELECTED HAZARDOUS CONSTITUENTS
CAS No.
67-64-1
75-05-8
98-86-2
107-13-1
309-00-2
62-53-3
7440-36-0
7440-39-3 .
71-43-2 . . ..
7440-41-7 . .
111-44-4
117-81-7
75-27-4
75-25-2
74-83-9
75-15-0 .
56-23-5
57-74-9
108-90-7.... ...
67-66-3
16065-83-1
7440-47-3 ....
108-39-4..
95-48-7
106-44-5 ..
57-12-5
72-55 9 ...
72-54-8
50-29-3... .
124-448-1
84-74-2
924-16-3 .
75-71-8
107-06-2
75-35-4
120-83-2.
60-57-1
84-66-2
55-18-5
60-51-5
62-75-9
51-28-5
88-85-7 .
1 22-39-4
298-04-4
100-41-4
76-44-8
1024-57-3
87-68-3
319-84-6 ..
319-85-7
58-89-9
-77-47-4
67-72-1.....
78-83-1
78-59-1
126-98-7 .
78-93-3
108-10-1
298-00-0
75-09-2
10595-95-6 _...
621-64-7
86-30-6
930 55-2
7440-02-0
98-95-3
56-38-2
608-93-5
82-68-8
87-86-5
,108-95-2......;
1336-36-2
23950-58-5
110-86-1
7440-22-4
100-42-5
Class
(B1)
(B2)..
(C)
(A)
(B2)
(B2)
(B2)
(B2)
(B2)
- :••-
(B2)
(B2)
(B2)
(B2)
(B2) „.
(C) „....
(B2)..
(B2). .
(B2).;
(B2).. „
(B2)
(C)
(C)
(C)
-
(B2)
-------
33422
' Iueiday> Au§ust 30- 1988 / Proposed Rules
APPENDIX II!.—CARCINOGENIC SLOPE FACTORS (CSF's) AND REFERENCE DOSES (RfD's) FOR SELECTED HAZARDOUS
CONSTITUENTS—Continued
CAS No,
85-84-3...™, .....
73-34-5
127-18-4
58-30-2 ....
ios-es-3 ..
8001-35-2
120-82-1.....,..,
71 -55-8.
70-00-5 .„.._ ....
79-01-6,.,...
75-69-4 .™™w....
OS-95-4 „„
88-06-2 ».„..„ —
Sfl-1 8-4 „.... ,_
1330-20-7.,
Class
(C),
(Q....
(6),...... ™J1!Z~
(B2)
—
(82).
Chemical name
1,2,4,5-Tetrachlorobenzene
1,1,2,2-Tetrachloroethane
Tetrachlofoethylene .
2,3,4.6-Tetrachlorophenol
Toluene ....„ „
1,2,4-Trlchlorobenzene
1,1.1-Trichtoreothane'
1,1,2-Trichloreothane ...„ '.
Trichtoroethylene "...... .
TricMoromonofluoromethane
2,4,5-TrichIorophenol ;
2,4,6-Trichlorophenol
1,2.3-TrichIoropropane .".
Xylenes
Health based levels for "
Systemic toxicants— RFD
(mg/kg/day)
3.0x1 £>-«
1.0X10-*
3.0X10-*
3.0X10-'
2.0X10-*
9.0X10-=
2.0x107tt
3.0X10-'
1.0X10-' ,
1.0x10-'
2
Carcinogens— CSF
(mg/kg/day)
0.2
5.1X10-=
1.1
5.7X10-2
1,1X10-"
0.02
• MCL's aro available for these constituents (see Table 2). MCL's should be used as trigger levels
tev«« (oSsan1 MCLw£is?d * carcin°9en ^ me oral route- RfD is based on non-carcinogenic effects only. Trigger levels should be based on the lower of the two
How to calculate trigger levels from RfDs
and RSDs:
I, Systemic Toxicants:
To calculate a trigger level based on a
reference done (RfD), multiply the RfD by the
average adult body weight (70 kg) over the
average watrar intake (2 liters of water per
d»y).
Example for acetonitrite:
RfD m O.OxlCr'mg/icg/day
0.0x10* * mg 70 kg
leg-day
2L/day
II. Carcinogens:
To calculate a trigger level based on a
carcinogenic slope factor (CSF). derive a risk-
specific dose (RSD). then multiply tie RSD by
the average adult body weight (70 kg) over
the average water intake (2 liters of water per
day).
example of aldrin:
A. Aldrin is classified as a Group B2
carcinogen; it has a CSF of 17 (mg/kg/day) "*.
Using a I(r6risk level, the RSD is:
=5.9xlO~8 mg/kg/day
17 (mg/kg/day)-'
The trigger level is:
5.9x10-' mg 70 kg
• x •
kg-day
2L/day
=2.1xlO-%ig/L
B. Using a 10~* risk level, the 'RSD is:
'S.QxlO-8 mg/kg/day
„„, ii /., \,
17 (mg/kg/day)-'
The trigger level Is:
5.9xlO"emg 70kg
kg-day
2L/day
=2.1xlO"4 nag/L
[FR Doc. 8&-19S30 Filed 8-29-88; 8:45 am]
BILLING CODE 6560-50-M
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