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Alternative Liner Performance, Leachate Recirculation, and Bioreactor Landfills: Request for Information and Data
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: April 6, 2000 (Volume 65, Number 67)]
[Proposed Rules]
[Page 18014-18018]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr06ap00-13]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 258
[FRL-6571-3; F-2000-ALPA-FFFFF]
Alternative Liner Performance, Leachate Recirculation, and
Bioreactor Landfills: Request for Information and Data
AGENCY: Environmental Protection Agency.
ACTION: Request for information and data.
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SUMMARY: EPA is requesting comments and information on two issues
related to the Criteria for Municipal Solid Waste Landfills. First, we
need data and information on the performance of alternative liner
designs compared to the performance of composite liners
[[Page 18015]]
when leachate is recirculated. Provisions in the municipal solid waste
landfill (MSWLF) criteria prohibit leachate recirculation at an MSWLF
unless the unit has a composite liner as described in these
regulations. Recently, various stakeholder groups (e.g., States, local
governments, solid waste associations, and industry) have suggested
that there are alternative liner designs that would work as well as, if
not better than, the specific liner designs currently required by the
criteria.
Second, EPA is also requesting data and information on the design
and performance of bioreactor landfills. In recent years, bioreactor
landfills have gained recognition as a possible innovation in solid
waste management. The bioreactor landfill is generally defined as a
landfill operated to transform and more quickly stabilize the readily
and moderately decomposable organic constituents of the waste stream by
purposeful control to enhance microbiological processes. Bioreactor
landfills often employ liquid addition including leachate
recirculation, alternative cover designs, and state-of-the-art landfill
gas collection systems.
DATES: EPA must receive your responses on leachate recirculation and
alternative liner performance by August 7, 2000. EPA must receive your
responses on bioreactors by October 6, 2000.
ADDRESSES: See section I of Supplementary Information below.
FOR FURTHER INFORMATION CONTACT:
For general information: Contact the RCRA Hotline at 800 424-9346
or TDD 800 553-7672 (hearing impaired). In the Washington, DC,
metropolitan area, call 703 412-9810 or TDD 703 412-3323.
For information on specific aspects of this document: Contact
Dwight Hlustick, Municipal and Industrial Solid Waste Division of the
Office of Solid Waste (mail code 5306W), U.S. Environmental Protection
Agency Headquarters (EPA, HQ) 1200 Pennsylvania Ave., NW, Washington,
DC 20460; 703/308-8647 [HLUSTICK.DWIGHT@EPAMAIL. EPA.GOV].
SUPPLEMENTARY INFORMATION:
I. Submitting Responses to This Document
How May I Respond to This Document?
What Information Should I Include in My Response?
What Will EPA Do With the Information You Submit?
II. What Will Be the Official Record for This Document?
How May I See Responses to This Document?
Where May I Find Information on This Action on the Internet?
III. What Is the Authority for This Request?
IV. Description of EPA's Current Municipal Solid Waste Landfill
Regulations
V. Description of Current Regulations for Landfill Liners
Performance Standard
Design Standard
VI. What Are Existing Requirements for Leachate Recirculation?
Description of Technical Guidance for Landfill Design
Description of Concerns With Respect to Leachate Recirculation
VII. What Information Would EPA Like to Have About Alternative Liner
Performance and Leachate Recirculation?
VIII. Concerns With Respect to Bioreactors
Information Needs With Respect to Bioreactors
IX. Conclusion
I. Submitting Responses on This Document
How May I Respond to This Document?
You may submit your information in hard copy (paper) or using
electronic mail. All comments must reference docket number F-2000-ALPA-
FFFFF. You should not submit electronically any confidential business
information.
Mail: Please submit an original and two copies to: RCRA
Docket Information Center, Office of Solid Waste (5305G), U.S.
Environmental Protection Agency Headquarters (EPA, HQ) 1200
Pennsylvania Ave., NW, Washington DC 20460.
Hand Deliveries: Please submit an original and two copies
of information to: RCRA Information Center (RIC), Crystal Gateway I,
First Floor, 1235 Jefferson Davis Highway, Arlington, Virginia.
Electronic Submittals: Please submit electronic
information through the Internet to: rcra-docket@epa.gov. Your
responses in electronic format must also be indentified by docket
number F-2000-ALPA-FFFFF. You must provide your electronic submittals
as ASCII files and avoid the use of special characters and any form of
encryption. You should not submit electronically any confidential
business information (CBI). An original and two copies of CBI must be
submitted under separate cover to: RCRA CBI Document Control Officer,
Office of Solid Waste (5305W), U.S. EPA, 1200 Pennsylvania NW,
Washington, DC 20460.
What Information Should I Include in My Response?
Your comments will be most effective if you follow the suggestions
below:
Explain your views as clearly as possible.
Provide solid technical data to support your views.
If you estimate potential costs, explain how you arrived
at the estimate.
Provide specific examples to illustrate your concerns.
Offer specific alternatives.
Refer your comments to specific sections of this notice or
MSWLF criteria.
Be sure to submit your information by the deadline in this
notice.
Be sure to include the name, date, and docket number with
your submittals.
What Will EPA Do With the Information You Submit?
We will review all responses to this action as well as additional
information in our own data base in considering whether to propose to
revise the Criteria for Municipal Solid Waste Landfills (40 CFR part
258). EPA will not respond directly on an individual basis to those
providing information to the Agency as a result of this action, but
will address issues raised by the respondents in future Federal
Register notices. In addition, all responses to this information
request notice will be incorporated into the docket for any rulemaking
proposals on the subject criteria.
II. What Will Be the Official Record for This Document?
The official record for this action will be kept in paper form.
Accordingly, EPA will transfer all electronic submittals into paper
form and place them in the official record, which will also include all
responses submitted directly in writing. The official record is the
paper record maintained at the RCRA Information Center (RIC), Crystal
Gateway I, First Floor, 1235 Jefferson Davis Highway, Arlington,
Virginia.
How May I See Responses to This Document?
All responses to this document are available for viewing in the
RCRA Information Center (RIC), located at Crystal Gateway I, First
Floor, 1235 Jefferson Davis Highway, Arlington, VA. The RIC is open
from 9 a.m. to 4 p.m., Monday through Friday, excluding federal
holidays. To review docket materials, we recommend that the public make
an appointment by calling 703 603-9230. The public may copy a maximum
of 100 pages from any regulatory docket at no charge. Additional copies
cost $0.15/page.
Where May I Find Information on This Action on the Internet?
Information on this action, consisting of this notice and a fact
sheet, may be found at the following Internet site: http://www.epa.gov/
epaoswer/non-hw/muncpl/landfill/leachate.htm.
[[Page 18016]]
III. What Is the Authority for This Request?
Any revisions to Criteria for Municipal Solid Waste Landfills (40
CFR part 258) will be made under Sections 1008, 2002 (general rule
making authority), 4004, and 4010 of the Resource Conservation and
Recovery Act of 1976, as amended. Revisions may also be made under
Section 405 of the Clean Water Act which addresses the disposal of
sewage sludge.
IV. Description of EPA's Current Municipal Solid Waste Landfill
Regulations
As specified in the Resource Conservation and Recovery Act, the
federal role is to establish overall regulatory direction through the
provision of minimum nationwide standards for MSWLFs. On October 9,
1991, EPA issued revised Criteria for Municipal Solid Waste Landfills
(40 CFR part 258; 56 FR 50978). These 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. MSWLFs typically receive
household waste, non-hazardous commercial, institutional and industrial
waste, household hazardous waste and conditionally exempt small
quantity generator (CESQG) hazardous waste. The criteria are
implemented in one of two ways. The first, and preferred alternative,
is that each State would implement the criteria after receiving
approval by EPA of its municipal solid waste landfill permit program or
other system of prior approval. The criteria contain provisions that
allow States to develop and rely on alternative approaches that deal
with site-specific conditions. Therefore, the actual planning and
direct implementation of solid waste programs is principally a function
of State governments and those owners and operators, including local
governments, of MSWLFs, not the federal government.
The second alternative is that the program would be self-
implementing by landfill owners and operators in those States that have
not received EPA approval of their MSWLF permitting programs. In this
case, the regulations provide less flexibility than for approved
States. As of March 1, 2000, 49 states and territories had received
approval of their programs and are implementing these regulations.
V. Description of Current Regulations for Landfill Liners
The criteria set forth two methods for complying with liner
requirements for municipal solid waste landfills. The first is a
performance standard and the second is a specific design standard.
Performance Standard
The performance standard is set forth in Sec. 258.40(a)(1). Under
this standard, a landfill owner or operator may rely on the design of
their choice, provided the design ensures that the concentration values
for the constituents listed in the following table will not be exceeded
in the uppermost aquifer at the relevant point of compliance as
determined by the Director of an approved State.
Table 1.--Concentration Values Not To Be Exceeded at the Point of
Compliance
------------------------------------------------------------------------
MCL
Chemical (mg/l)
------------------------------------------------------------------------
Arsenic........................................................ 0.05
Barium......................................................... 1.0
Benzene........................................................ 0.005
Cadmium........................................................ 0.01
Carbon tetrachloride........................................... 0.005
Chromium (hexavalent).......................................... 0.05
2,4-Dichlorophenoxy acetic acid................................ 0.1
1,4-Dichlorobenzene............................................ 0.075
1,2-Dichloroethane............................................. 0.005
1,2-Dichloroethylene........................................... 0.007
Endrin......................................................... 0.0002
Fluoride....................................................... 4
Lindane........................................................ 0.004
Lead........................................................... 0.05
Mercury........................................................ 0.002
Methoxychlor................................................... 0.1
Nitrate........................................................ 10
Selenium....................................................... 0.01
Silver......................................................... 0.05
Toxaphene...................................................... 0.005
1,1,1-Trichoromethane.......................................... 0.2
Trichloroethylene.............................................. 0.005
2,4,5-Trichlorophenoxy acetic acid............................. 0.01
Vinyl Chloride................................................. 0.002
------------------------------------------------------------------------
The point of compliance can be no more than 150 meters from the
waste management unit boundary and must be on land owned by the owner
of the MSWLF (see 40 CFR 258.40(d)). The criteria require that in
determining whether the performance standard is met, the Director of
the approved State program shall consider the following factors in his/
her determination:
1. The hydrogeologic characteristics of the facility and the
surrounding land;
2. The volume and the physical and chemical characteristics of the
leachate;
3. The quantity, quality, and direction of flow of ground water;
4. The proximity of and withdrawal rate of the groundwater 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, and whether the ground water is currently used or reasonably
expected to be used for drinking water;
7. Public health, safety, and welfare effects; and
8. Practical capability of the owner or operator.
Design Standard
The second method for compliance with the criteria is to install a
liner system that meets the specific design criteria described in 40
CFR 258.40(a)(2) and set forth in 40 CFR 258.40(b). Section
258.40(a)(2) states that the liner system must contain a composite
liner and Section 258.40(b) defines a composite liner as a system
comprised of two components:
1. An upper component consisting of a minimum of 30 mil flexible
membrane liner (60 mil if high density polyethylene (HDPE) is used);
and
2. a lower component consisting of compacted soil at least two feet
deep with a hydraulic conductivity of no more than 1x 10-7
cm/sec.
We based this decision on a desire to ensure that leachate reaching
the liner would be efficiently collected (56 FR 51056). The design
standards require that the leachate collection system be capable of
maintaining a hydraulic head within the landfill of 30 cm or less.
VI. What Are the Existing Requirements for Leachate Recirculation?
The liquid restrictions in Subpart C of Part 258 only allow
leachate recirculation in MSWLFs that are constructed with a composite
liner and leachate recirculation system as described in 40 CFR
258.28(a)(2). The recirculation of leachate is not allowed in landfills
which have an alternative liner design even if the design meets the
performance standard in 40 CFR 258.40(a)(1). At the time these
regulations were promulgated, we believed MSWLFs needed a composite
liner and leachate control system as described at 40 CFR 258.40(a)(2)
to ensure that ground water would be protected.
Description of Technical Guidance for Landfill Design
EPA published a technical manual entitled ``Solid Waste Disposal
Criteria'' (EPA530-R-93-017, NTIS PB94-100-450, Internet site: http://
www.epa.gov/epaoswer/non-hw/muncpl/landfill/techman/) in 1993. Chapter
4 of this manual entitled ``Design Criteria'' sets forth additional
guidance in the
[[Page 18017]]
following areas: (1) Design concepts, (2) design calculations, (3)
physical properties, and (4) construction methods. This chapter of the
guidance document also addresses the following:
Designs Based on the Performance Standard
Leachate characterization and leakage assessment;
Leachate migration in the subsurface;
Leachate migration models;
Relevant point of compliance assessment.
Description of Concerns With Respect to Leachate Recirculation
Many MSWLF stakeholders (e.g., States, local governments, solid
waste associations, and industry) believe that under certain
conditions, leachate recirculation should be allowed when alternative
liners are used. In fact, some believe that alternative liner
technologies can be superior to the composite liner design specified in
the criteria. We are trying to determine if it is possible to design
and operate MSWLFs safely when alternative liner designs are used and
leachate is recirculated. As required by the regulations, such an
alternative liner design must assure that the performance standard
specified at 40 CFR 258.40(a)(1) and the requirement to maintain a
hydraulic head within the landfill of 30 cm. or less are met.
VII. What Information Would EPA Like to Have About Alternative
Liner Performance and Leachate Recirculation?
We are interested in determining whether and which types of
alternative liners are capable of meeting the design performance
standard described above including maintaining a hydraulic head at
acceptable levels.
More specifically we are seeking data and information on the
following issues and questions:
Should EPA revise the MSWLF regulations to allow leachate
recirculation when alternative liners are used, and under what
conditions should leachate recirculation be allowed?
Should only specified alternative liner designs be allowed
if leachate is recirculated?
When alternative liners are used, what would be the impact
of leachate recirculation on leachate quality and quantity and
attainment of the concentration values specified in Table 1 in ground
water at the point of compliance?
Does EPA need to specify other requirements in the MSWLF
Criteria to ensure that landfills that recirculate leachate when using
alternative liners protect ground water and maintain the hydraulic head
with the landfill at 30 cm. or less?
To what degree does leachate recirculation accelerate the
stability of the leachate and the remaining decomposable solids in a
landfill? How can EPA make a determination when a landfill is
sufficiently stabilized?
Should EPA revise the technical manual? If so, how? We are
particularly interested in information on how to advise owners and
operators to characterize leachate and leachate leakage rates properly
when conducting leakage migration modeling to demonstrate that a
landfill which recirculates leachate meets the performance standard
specified in 40 CFR 258.40(a)(1). For example, should we be suggesting
different methodologies to quantify input parameters? Are there non-
steady state situations that we should be addressing in the guidance?
What are the effects of leachate recirculation on heavy metals in the
leachate, and subsequently in the ground water? Should the groundwater
models identified in this guidance be updated? If so, what models are
appropriate?
VIII. Concerns With Respect to Bioreactors
Recent communications from MSWLF stakeholders indicate that there
is a growing interest in bioreactor landfills. Bioreactor landfills
represent a potential new approach to solid waste management. A
bioreactor landfill can be generally defined as a sanitary landfill
operated to transform and stabilize the readily and moderately
decomposable organic constituents of the waste stream by purposeful
control to enhance microbiological processes. While categorizations of
bioreactor landfills vary, operational parameters often employ leachate
recirculation, alternative cover designs, liquids addition to optimize
moisture content in the waste, and state-of-the-art landfill gas
collection systems. Bioreactor landfills have been operated under both
anaerobic and aerobic conditions. Thus, the term bioreactor landfill is
a management concept for MSWLFs encompassing a variety of MSWLF
practices.
Information Needs With Respect to Bioreactors
At this time, EPA lacks adequate data and information on the
design, operation, and performance of bioreactor landfills to evaluate
this technology. We are unsure about the appropriateness of revising
the MSWLF Criteria, as some stakeholders have suggested to the Agency,
to allow for design and operation of bioreactor landfills (e.g.,
allowing the addition of additional liquids to municipal landfills to
optimize waste degradation). Therefore, we are today seeking data and
other information on the design, operation, and performance of
bioreactor landfills. We are specifically requesting comment and data
in the following areas.
The nature and scope of current bioreactor landfill
projects both within the U.S. and abroad.
The impact (advantages and disadvantages) of leachate
recirculation and liquids addition (with or without the addition of
air) on leachate quality, waste settlement, waste slope and stability,
and landfill gas yield.
Modifications that have been made to daily cover to
optimize biodegradation.
Changes to final cover that have been made to optimize
biodegradation or to incorporate materials which convert landfill gas
to carbon dioxide and water. See, for example ``Approaching Sustainable
Landfilling,'' Alexander Zach, et al.; and ``Biological Pretreatment of
MSW as a Measure to Save Landfill Volume and Deter Birds,'' Florian
Koelsch and Richard T. Reynolds, Proceedings of Fifteenth International
Conference on Solid Waste Technology and Management, December 12-15,
1999, Philadelphia, PA. Proceedings published by Widener University
School of Engineering and the University of Pennsylvania.
Additional monitoring requirements necessary to ensure
that a bioreactor (with or without air addition) is functioning
properly over the life of the landfill.
Approaches that have been taken to close bioreactor
landfills and to care for the landfill during the post-closure care
period to ensure protection of human health and the environment.
The potential public health, environmental, and economic
impacts of adding liquid wastes, such as sewage sludge, grey water or
animal feedlot liquid wastes to the MSWLF.
For bioreactors which have been operating in the aerobic
mode, what methods have been used to provide for aeration and how to
control temperature in the waste mass.
The appropriateness of liner designs different from the
specific design described in 40 CFR 258.40(a)(2) when liquids are added
to a MSWLF to enhance biodegradation.
Project economics for the design, construction, and
operation of
[[Page 18018]]
bioreactor landfills (with or without air addition).
The Clean Air Act Section 111(d) and greenhouse gas
emissions impact of operating a municipal solid waste landfill as a
bioreactor landfill, i.e., will the addition of air or liquids affect
the ability of a landfill to comply with air regulations?
The comparative cost effectiveness and environmental
benefits of the bioreactor landfill relative to managing segregated
organic wastes through composting and placing non-compostable waste in
a standard municipal landfill (i.e., one not operated as a bioreactor).
Are there management and safety issues associated with
landfill gas generation and control at bioreactor landfills that need
to be addressed in regulations or guidance?
Are there relevant patent issues associated with
anaerobic, aerobic, or other bioreactor landfills of which EPA should
be aware?
IX. Conclusion
After reviewing the literature on leachate recirculation,
alternative liner designs, and bioreactor landfills and information and
data received during this comment period, the Agency will make a
determination concerning what future actions, if any, we will take on
the issues discussed in this document.
Dated: March 22, 2000.
Elizabeth Cotsworth,
Director, Office of Solid Waste.
[FR Doc. 00-8400 Filed 4-5-00; 8:45 am]
BILLING CODE 6560-50-P