[Federal Register Volume 60, Number 154 (Thursday, August 10, 1995)]
[Proposed Rules]
[Pages 40799-40812]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-19666]



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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 258

[FRL-5275-3]
RIN 2050-AE24


Alternatives for Ground-Water Monitoring and Delay of General 
Compliance Date for Small Municipal Solid Waste Landfills Located in 
Either Dry or Remote Areas

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of proposed rulemaking and request for comment.

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SUMMARY: On October 9, 1991, the Environmental Protection Agency (EPA) 
promulgated final solid waste disposal facility criteria (40 CFR Part 
258), setting in place national minimum standards for municipal solid 
waste landfills (MSWLFs). In that rulemaking, the Agency provided an 
exemption from ground-water monitoring for small MSWLF units located in 
dry or remote locations. The Agency provided this relief as it sought 
to balance the protection of human health and the environment with the 
practicable capability of these small community landfill owners and 
operators.
    In 1993, the U.S. Court of Appeals for the District of Columbia 
vacated this ground-water monitoring exemption. The Agency today is 
proposing to provide to approved States and Tribes the flexibility to 
determine alternative ground-water monitoring requirements, on a site-
specific basis, for small MSWLFs that are located in either dry or 
remote areas (hereafter referred to as ``qualifying small MSWLFs''). 
Under this proposal, approved States and Tribes may consider site-
specific alternatives to conventional ground-water monitoring that are 
relatively low in cost and are still capable of detecting 
contamination. Through the use of ground-water monitoring alternatives, 
the Agency estimates potential annual national cost savings of between 
$5.9 million to $22.2 million. The Agency is providing a 90-day comment 
period for this portion of today's proposal.
    Today's rulemaking also solicits comment on a delay of the general 
compliance date of the MSWLF criteria for qualifying small MSWLFs. The 
Agency is providing a 30-day comment period for this separate portion 
of today's proposal.

DATES: The Agency is accepting public comments on the proposed rule 
changes related to the delay of the compliance date for small MSWLFs 
located in dry and remote areas in Secs. 258.1(d)(3), 258.1(e)(4), 
258.2, and 258.50(e) for a 30-day period beginning on August 10, 1995. 
The Agency also is accepting public comments on a separate proposed 
rule change allowing the use of alternative ground-water monitoring 
methods in Sec. 258.50(a) for a 90-day period beginning on August 10, 
1995.

ADDRESSES: The public should submit an original and two copies of their 
comments on this proposed rule to the Docket Clerk (5305), U. S. 
Environmental Protection Agency, 401 M Street, SW., Washington, DC 
20460. All written comments received by EPA regarding the delay of the 
compliance date will be placed in public docket number F-95-AGDP-FFFFF. 
Please place the docket number F-95-AGDP-FFFFF on the comments 
submitted to the Agency on this issue. Written comments received by EPA 
regarding the use of alternative ground-water monitoring methods will 
be placed in public docket number F-95-AGAP-FFFFF. Please place the 
docket number F-95-AGAP-FFFFF on the comments submitted to the Agency 
on this issue.
    Background information collected in support of today's proposed 
rule may be found in public docket number F-95-AGAP-FFFFF. All dockets 
are available for viewing in the RCRA Information Center (RIC), located 
in Room M2616, U.S. EPA, 401 M Street SW., 

[[Page 40800]]
Washington, DC 20460. The RIC is open from 9 a.m. to 4 p.m., Monday 
through Friday, except for Federal holidays. The public must make an 
appointment to view docket materials. Call 202-260-9327 for an 
appointment. Copies cost $0.15 per page for materials exceeding 100 
pages.

FOR FURTHER INFORMATION CONTACT: For general questions on this proposed 
rule, contact the RCRA/Superfund Hotline at 1-800-424-9346, TDD 1-800-
553-7672 (hearing impaired); in the Washington, DC metropolitan area 
the number is 703-412-9810, TDD 703-412-3323. For technical questions, 
contact Mr. Andrew Teplitzky (703-308-7275) or Mr. Allen Geswein (Phone 
703-308-7261): Office of Solid Waste, U.S. Environmental Protection 
Agency, Mail Code 5306W, 401 M St. SW., Washington, DC 20460.

SUPPLEMENTARY INFORMATION:

Preamble Outline

I. Authority
II. Background
    A. 40 CFR Part 258 and Small Landfill Exemption
    B. Special Circumstances of Small Communities and Related Public 
Comments
    1. Influence of Certain Hydrogeologic and Climatic Factors on 
Leachate Generation and Potential Ground-Water Contamination at 
Small Landfills
    2. Limited Financial Resources
    3. Obstacles to Regional Solid Waste Management Practices
    4. Likelihood of Increased Illegal Dumping
    C. Additional Public Comments
    1. Comments on Alternatives
    2. Comments on 40 CFR 258.50(b), Demonstration of No Potential 
for Migration
    3. Proposal for Extension to General Compliance Date
III. Alternatives to Ground-Water Monitoring
IV. Proposed Rule for Alternatives to Ground-Water Monitoring
    A. Overview
    B. Proposed Approach for Using Alternatives
    1. Consideration of Site-Specific Factors in Selection of an 
Alternative Monitoring Technique
    2. Phased Approach to Alternative Ground-Water Monitoring
V. Role of States and Tribes
VI. Consideration of Issues Related to Environmental Justice
VII. Impact Analysis
    A. Executive Order 12866
    B. Regulatory Flexibility Act
    C. Paperwork Reduction Act
    D. Executive Order 12875
    E. Unfunded Mandates
I. Authority

    The Agency is proposing today's regulations under the authority of 
section 4010(c) of the Resource Conservation and Recovery Act (RCRA), 
as amended, 42 U.S.C. 6949a(c). Section 4010(c) requires EPA to 
establish appropriate ground-water monitoring, location, and corrective 
action criteria for MSWLFs that may receive household hazardous wastes 
or hazardous waste from small quantity generators. Section 4010(c) 
States that: ``At a minimum such revisions for facilities potentially 
receiving such wastes should require ground-water monitoring as 
necessary to detect contamination, establish criteria for the 
acceptable location of new or existing facilities, and provide for 
corrective action as appropriate.''

II. Background

A. 40 CFR Part 258 and Small Landfill Exemption

    On August 30, 1988, the Agency published proposed landfill criteria 
under Subtitle D of RCRA (53 FR 33314), including minimum federal 
criteria for location restrictions, facility design and operation, 
ground-water monitoring, corrective action, financial assurance, and 
closure and post-closure care requirements. The Agency received over 
350 public comments in response to the proposed criteria.
    The Agency received a significant number of public comments on the 
impact the proposal would have on small communities that own and 
operate small landfills. Commentors were concerned that: (1) Small 
communities face shortages of technical professionals trained in 
landfill design and operating practices; (2) small communities have 
insufficient financial resources to be able to comply with the most 
costly requirements of the criteria (i.e., the design and ground-water 
monitoring requirements); and (3) a resurgence in illegal dumping would 
occur if the proposed criteria resulted in closures of small landfills.
    Responding to these concerns in the landfill criteria final rule, 
published on October 9, 1991 (56 FR 50978), EPA included an exemption 
for owners and operators of certain small MSWLF units from the design 
and ground-water monitoring requirements of the criteria. To qualify 
for the exemption, the small landfill could only accept less than 
twenty tons of municipal solid waste per day (based on an annual 
average), have no evidence of existing ground-water contamination, and 
either: (1) Serve a community that experiences an annual interruption 
of at least three consecutive months of surface transportation that 
prevents access to a regional waste management facility, or (2) be 
located in an area that annually receives less than or equal to 25 
inches of precipitation and serve a community that has no practicable 
waste management alternative. In adopting this limited exemption, the 
Agency believed it had complied with the statutory requirement to 
protect human health and the environment, taking into account the 
practicable capabilities of small landfill owners and operators.
    In January, 1992, the Sierra Club and the Natural Resources Defense 
Council (NRDC) filed a petition with the U.S. Court of Appeals, 
District of Columbia Circuit, for review of the Subtitle D criteria. 
The Sierra Club and NRDC alleged, among other things, that EPA exceeded 
its statutory authority when it provided for an exemption for certain 
landfills from the ground-water monitoring requirements. On May 7, 
1993, the Court of Appeals issued its opinion in Sierra Club v. United 
States Environmental Protection Agency 992 F.2d 337 (D.C. Cir. 1993). 
The Court determined that under RCRA section 4010(c), the only factor 
EPA could consider in determining whether facilities must monitor 
ground-water was whether such monitoring was ``necessary to detect 
contamination,'' not whether such monitoring is ``practicable.'' Thus, 
the Court vacated the small landfill exemption as it pertains to 
ground-water monitoring, and remanded that portion of the final rule to 
the Agency for further consideration. The Court did not require EPA to 
remove the exemption for design requirements, since the Sierra Club and 
NRDC did not challenge the final rule's exemption from the design 
requirement.
    Consequently, as part of the Agency's October 1, 1993 final rule 
delaying the effective date of the MSWLF criteria (58 FR 51536; October 
1, 1993), EPA rescinded the exemption from ground-water monitoring for 
qualifying small MSWLFs. At the same time, however, EPA delayed the 
effective date of the MSWLF criteria for qualifying small MSWLFs for 
two years (until October 9, 1995), to allow owners and operators of 
such small MSWLFs adequate time to decide whether to continue to 
operate in light of the Court's ruling, and to prepare financially for 
the added costs if they decided to continue to operate. This additional 
two-year period also was intended to provide time for EPA to determine 
if there are practical and affordable alternative monitoring systems or 
approaches that are adequate to detect contamination.
    The U.S. Court of Appeals decision does not preclude EPA from 
issuing separate ground-water monitoring standards for these landfills, 
taking into account size, location, and climate, as long as these 
separate standards ensure that any ground-water contamination 

[[Page 40801]]
would be detected. The Agency, therefore, solicited comments on 
alternative ground-water monitoring requirements in the publication of 
the proposed rule to extend the effective date of the MSWLF criteria 
(56 FR 40568, July 28, 1993), and later, held a series of related 
public meetings.
    The Agency announced on May 9, 1994, that it would hold a series of 
four public meetings to provide an additional opportunity for 
interested parties to present the Agency with information regarding the 
costs of monitoring ground water at qualifying small MSWLF units, and 
on any cost-effective alternatives to conventional ground-water 
monitoring (59 FR 23857). These four meetings were held in June, 1994, 
in Midland, Texas; Salt Lake City, Utah; Anchorage, Alaska; and 
Washington, DC. Approximately 60 commentors representing State and 
local governments, landfill owners and operators, geologists, 
engineers, and other parties involved in waste management presented 
testimony at those meetings. A copy of these comments may be found in 
public docket number F-95-AGAP-FFFFF.
    Based on the public comments submitted in response to the 1988 
proposed rule, the additional comments received at these public 
meetings, and on related Agency research, the Agency continues to 
believe that certain qualifying small MSWLFs warrant special 
consideration with respect to their ground-water monitoring 
requirements.

B. Special Circumstances of Small Communities and Related Public 
Comments

    In the preamble (56 FR 50989 through 50991, October 9, 1991) to the 
Solid Waste Disposal Facility Criteria Final Rule codified under 40 CFR 
part 258, the Agency discussed the particular circumstances of small 
remote communities and the hardships those communities would face if 
they had to comply with all of the ground-water monitoring requirements 
of part 258. These circumstances were, in part, the basis for the small 
landfill exemption described in the previous section of this preamble. 
Although the ground-water monitoring portion of the exemption has been 
deleted, the Agency still believes that it may not be necessary or 
appropriate to require qualifying small MSWLFs in arid or remote areas 
to comply with the full ground-water monitoring requirements in part 
258.
    As indicated in the preamble to part 258, circumstances that 
characterize small communities and their landfills may include: (a) 
Certain mitigating hydrogeologic and climatic factors, and their 
influence on impacts to ground water; (b) limited financial resources 
and technical expertise to comply with the design and ground-water 
monitoring provisions; (c) financial and practical obstacles to 
providing regionalized solid waste management practices, such as large 
geographic distances between communities, or geographic isolation for 
extended periods of time due to winter weather conditions; and (d) the 
potential for increased illegal dumping if small landfills are no 
longer available or regionalization of solid waste is impractical or 
excessively expensive. The next section of the preamble describes these 
circumstances in more detail and discusses additional information 
provided by commentors at the four public meetings.
1. Influence of Certain Hydrogeologic and Climatic Factors on Leachate 
Generation and Potential Ground-Water Contamination at Small Landfills
    The risks of contamination posed by qualifying small MSWLFs vary 
from location to location and depend on an array of climatic, geologic, 
and hydrogeologic factors. It was asserted by most commentors that 
MSWLF units meeting the criteria of 258.1(f)(1) pose a relatively low 
risk of contamination to ground water. The reasons for this, the 
commentors noted, are that qualifying small, dry MSWLFs (and many of 
the remote MSWLFs in Alaska) are situated in areas receiving very small 
amounts of precipitation, and in such ``dry'' areas where 
evapotranspiration often exceeds precipitation annually, the amounts of 
leachate generated would be minimal. Several commentors reflected that, 
in general, lower levels of precipitation decrease the probability for 
leachate generation at MSWLFs, corresponding to a decreased potential 
for adverse environmental impacts. Commentors stated that the time of 
year and the frequency and intensity of a precipitation event may 
significantly affect the potential for leachate generation. Commentors 
also remarked that in many arid western locations, ground-water is 
located hundreds of feet below the surface and may be separated from 
the landfill by rock formations with relatively low permeabilities. 
Commentors contended that migration of leachate to the ground-water 
table in such climatic and geologic conditions would be unlikely.
    When the D.C. Circuit Court of Appeals remanded the ground-water 
monitoring exemption in the final MSWLF criteria back to the Agency in 
Sierra Club v. U.S. EPA, the Court stated that the ``record provides no 
basis to conclude that * * * the aridity of a facility's climate 
suffices to establish that ground-water monitoring is not `necessary to 
detect contamination.' '' 992 F.2d at 345. Today's proposal, rather 
than using the aridity of a facility's climate to provide a ground-
water monitoring exemption, uses aridity as a basis for allowing 
approved States and Tribes to permit the use of alternative monitoring 
techniques. The Agency is proposing to grant this authority to approved 
States and Tribes because it believes that small landfills located in 
arid areas of the U.S. are less likely to present a threat of 
contamination due to the dry climate and often great distance to ground 
water. It is important to note that this is not an exemption, but 
rather it enables approved States and Tribes to tailor monitoring 
programs based on site-specific characteristics.
    The Agency continues to believe that ground-water monitoring plays 
an important role in ensuring protection of human health and the 
environment. However, the Agency believes that the relative public 
health and environmental risks posed by very small landfills located in 
arid areas is quite low, based on several reasons.
    First, as noted by the commentors, lower levels of precipitation 
decrease the probability for leachate generation at MSWLFs. Agency 
water balance studies used to predict leachate generation from MSWLFs 
indicate that landfills located in dry areas generate very little 
leachate available for release to the ground water. In addition, the 
Agency's Subtitle D Risk Model used to predict human health risk 
resulting from landfills based on a variety of factors, showed that 
while no single factor is responsible for determining overall risk 
(i.e., risk results from a complex interaction of factors), a much 
lower risk of contamination exists from landfills located in dry areas 
of the country experiencing low net infiltration of precipitation 
versus wet areas with high net infiltration.
    The Agency's choice of 25 inches of precipitation per year as a 
cut-off for the small landfill exemption contained in the original 
final MSWLF criteria was based, in part, on case studies on ground-
water contamination from MSWLFs developed from State data. (A copy of 
these case studies may be found in public docket F-95-AGAP-FFFFF. The 
25 inch cut-off was selected because, in part, under these conditions, 
evapotranspiration exceeds precipitation, making very little 
precipitation available to infiltrate the soil. Evapotranspiration is 
the portion of precipitation returned to the atmosphere by direct 
evaporation, by transpiration 

[[Page 40802]]
of vegetation, or by sublimation from snow and ice. In addition, many 
of the locations characterized by net evapotranspiration also have 
ground water located at great depths, further reducing the risk of a 
small amount of leachate that could be generated by these small 
landfill from ultimately reaching the ground water. For these reasons, 
the Agency believes that the 25 inch annual precipitation criterion in 
the original small landfill exemption represents a reasonable cut-off 
for qualifying for the ground-water monitoring flexibility in today's 
rule. The Agency specifically requests data (for docket number F-95-
AGAP-FFFFF) that either supports the 25 inch cut-off or provides the 
basis for establishing another criterion as a qualifier for today's 
flexibility.
    Second, in addition to the low precipitation, the size of the 
landfill plays another factor in the potential for leachate generation. 
Agency water balance studies used to predict leachate generation from 
MSWLFs indicate a relationship between the area of a landfill surface 
and the quantity of leachate generated over time, whereby the smaller 
the surface area of the landfill, the lower the quantity of leachate 
generated. In general, landfills receiving small amounts of waste 
occupy less surface area than landfills receiving larger amounts of 
waste. The Agency's Subtitle D Risk Model was used to predict risk as a 
function of landfill size. Again, while no single factor is responsible 
for overall risk from a landfill, the model generally predicted a much 
lower risk of contamination from the smallest class of landfills 
modelled (approximately less than 20 TPD) relative to larger 
facilities. The Agency believes that the 20 TPD cut-off in the original 
small landfill exemption continues to represent a reasonable limit for 
qualifying as a small landfill for today's rule. Additional explanation 
of the 20 TPD limitation is contained in the preamble to the final 
MSWLF criteria (56 FR 50989-50991, October 9, 1991).
    While a landfill may be small and dry, it may not always be a 
candidate for today's ground-water monitoring flexibility. Therefore, 
today's rule would require Directors of approved programs to assess the 
viability of alternative monitoring techniques on a site-specific 
basis. For example, the Agency recognizes that sources of moisture in 
addition to precipitation, such as ground-water intrusion into the 
landfill and the release of ambient waste moisture through waste 
degradation and compression, should be considered on a site-specific 
basis along with the influences of size, climate, and geology when 
determining the ground-water monitoring requirements for a particular 
landfill.
    The Agency continues to be aware of constraints on small community 
landfills located in geographically isolated areas where it is 
economically impracticable for the community to take advantage of a 
regional waste management facility. While today's proposal is limited 
to arid landfills (i.e., those located in areas receiving less than 25 
inches of precipitation annually), the Agency recognizes that some 
small landfills located in areas receiving greater than 25 inches of 
annual precipitation also may face economic hardships associated with 
getting access to a regional waste management facility and therefore 
would also desire to take advantage of cost-efficient alternative 
monitoring methods, where conditions are appropriate.
    Thus, it may be appropriate for landfills serving small populations 
in geographically isolated areas receiving greater than 25 inches of 
annual precipitation to take advantage of alternative monitoring 
methods where the local hydrogeology of the site minimizes, to a large 
extent, the migration of leachate to ground water. For example, areas 
with deep water tables and an adequate thickness of low permeability 
soil or rock between the landfill and water table could be candidates 
for using alternative monitoring methods. Other such landfills may be 
located in areas where bedrock (or permafrost in Alaska) exists at or 
near the base of the landfill, causing any potential leachate to 
migrate laterally over the bedrock rather than vertically to ground 
water below. Here again, a simplified alternative monitoring strategy 
may provide a more cost-effective and equally accurate method of 
detecting a release from the landfill.
    Small communities in areas receiving greater than 25 inches of 
annual precipitation face many of the same financial problems that 
exist in arid areas. Therefore, the Agency also is requesting comment 
(for docket number F-95-AGAP-FFFFF) on the appropriateness of extending 
today's flexibility to any small landfill that has no practicable waste 
management alternative. The Agency solicits comment (for docket number 
F-95-AGAP-FFFFF) on whether alternative monitoring methods will detect 
contamination in more humid environments.
    Because higher annual precipitation could lead to additional 
leachate generation at a landfill, the Agency believes that site-
specific conditions (e.g., hydraulic conductivity, depth to the 
uppermost aquifer) become increasingly important factors when 
considering whether to extend today's flexibility to non-arid small 
landfills. At this time, the Agency does not have sufficient data to 
identify those situations where it would be appropriate for small 
landfills in non-arid areas to use alternative ground-water monitoring 
methods to detect contamination. Therefore, the Agency requests 
comments (for docket number F-95-AGAP-FFFFF) and data on an appropriate 
set of hydrogeologic conditions that should exist at a small landfill 
before it could qualify for today's proposed flexibility to use 
alternative monitoring techniques.
2. Limited Financial Resources
    A number of States and local governments have submitted cost data 
regarding ground-water monitoring demonstrating the high cost of 
ground-water monitoring at a landfill serving smaller communities where 
economies of scale are not available to decrease per capita or per 
household costs.
     The Texas Natural Resource Conservation Commission (TNRCC) 
reported that as many as 110 communities in west Texas (served by 
qualifying small MSWLFs) would be significantly impacted by existing 
part 258 ground-water monitoring requirements. TNRCC reports that if 
part 258 ground-water monitoring requirements are fully implemented, 
they would increase average monthly household waste disposal costs in 
the 110 communities by 285 percent.
     The New Mexico Environment Department indicated that 
application of all part 258 ground-water monitoring requirements would 
increase waste disposal costs per household by approximately $44.00 per 
month in communities served by qualifying small MSWLFs.
     The Alaska Department of Environmental Conservation (ADEC) 
reports that for the 289 qualifying small MSWLFs in Alaska, a total 
capital cost of approximately $6.5 million would be incurred just for 
the cost of installing monitoring wells (which is cited to be about 
one-third of the annual construction budget for village sanitation 
facilities in Alaska). ADEC reports annual cost estimates of $10,600 
per facility for sample collection, shipping, and analysis, assuming 
the landfill has four monitoring wells sampled twice annually. ADEC 
states that the average community operating budget (for a population of 
about 800 

[[Page 40803]]
individuals) is $50,000 to $80,000 per year for all services, not just 
solid waste; therefore, ground-water monitoring alone would consume on 
average about 13-20% of a community's budget.
    As discussed in the Preamble to the final part 258 MSWLF criteria 
(56 FR 50989), the Agency recognized that the landfill criteria could 
have a significant economic impact on those small landfills that could 
not regionalize to benefit from the economies of scale available to 
larger MSWLFs. RCRA Sec. 4010(c) directed the Agency to promulgate 
MSWLF criteria ``necessary to protect human health and the environment 
* * * [taking] into account the practicable capability of such 
facilities (emphasis added).'' The Agency, when it developed the MSWLF 
criteria, interpreted the phrase ``practicable capability'' to allow 
for the consideration of the cost of the criteria to MSWLF owners and 
operators (see 56 FR 509830). Therefore, the Agency included a small 
landfill exemption in the original MSWLF criteria to exempt lower risk 
small MSWLFs from the two highest cost components of the rule: ground-
water monitoring (27 percent of the total costs) and liners/leachate 
collection systems (40 percent of the total costs).
    Based on the low risk associated with the qualifying small MSWLFs 
(as discussed in the previous section of today's preamble) and the high 
costs associated with full ground-water monitoring for qualifying small 
MSWLFs, the Agency continues to believe that some relief is warranted 
for these MSWLFs. Cost information developed by the Agency (discussed 
in Section VII of this Preamble), and similar information submitted in 
public comments and summarized above, indicates a significant financial 
burden would be placed on small communities due to implementation of 
all of the part 258 ground-water monitoring requirements. In 
particular, the Agency remains concerned about communities with 
exceptionally low operating budgets that are unable to participate in 
regional arrangements with neighboring communities to lower their cost 
of compliance. The ground-water monitoring flexibility provided in 
today's proposal is designed to alleviate some of the cost burden on 
affected small landfills, while still ensuring detection of 
contamination to ground water.
3. Obstacles to Regional Solid Waste Management Practices
    In some areas of the U.S., the cost of compliance with the MSWLF 
criteria can be shared among a number of communities through the use of 
a regional disposal facility. However, the preamble of part 258 final 
rule (56 FR 50989) discusses why regionalization of solid waste 
management is not feasible for many small communities. The preamble 
states that, in addition to economic constraints, significant 
geographic obstacles exist particularly in remote areas of the country 
where communities are separated by great distances or where surface 
transportation is not available for extended periods of time during the 
year (such as in Alaska).
    The Agency has performed an analysis to determine the costs for 
closing small landfills, opening a transfer station, and hauling a 
community's waste to a regional facility. The analysis concludes that 
for a 10 ton per day (TPD) landfill, the total annual cost is about 
$160,000 ($160 per household). For a 1 TPD landfill, the total annual 
cost is about $18,000 ($180 per household). This analysis assumes a 
one-way land traveled distance of 65 miles as discussed in the docket 
for this rulemaking (F-95-AGAP-FFFFF). The higher annual household cost 
for the 1 TPD landfill versus the 10 TPD facility arises from a smaller 
number of households being served by the 1 TPD facility. This cost 
analysis is discussed further in technical background document located 
in docket number F-95-AGAP-FFFFF.
    Small remote communities also may experience practical obstacles to 
regional solid waste management. Commentors at the public meetings 
related the difficulties associated with transporting waste where 
communities are separated by large geographic distances, or are served 
only by unimproved roads that are not likely to be adequate for heavy 
truck traffic. In certain areas of Alaska, road systems may not be 
available at all.
4. Likelihood of Increased Illegal Dumping
    Many commentors have asserted that the number and extent of illegal 
dump sites will increase dramatically if small landfills are no longer 
available or if the regionalization of solid waste is impractical or 
excessively expensive. This assertion is supported by data provided by 
the Texas Natural Resource Conservation Commission (TNRCC) and 
contained in docket number F-95-AGAP-FFFFF, that suggest a positive 
correlation between landfill closures and illegal dumping in Texas for 
the years 1988-1994.

C. Additional Public Comments

1. Comments on Alternatives
    When the Agency announced the public meetings on alternatives to 
ground-water monitoring (59 FR 23857, May 9, 1994), it asked for 
commentors to provide ideas regarding potential alternatives and their 
costs and limitations. This section describes various technical 
approaches to alternatives to ground-water monitoring that were 
mentioned at these public meetings.
    Commentors strongly encouraged EPA to provide States and Tribes 
with greater flexibility to determine ground-water monitoring 
requirements for qualifying small MSWLFs, including the flexibility to 
allow alternatives to conventional ground-water monitoring on a site-
specific basis. Commentors indicated that in determining alternatives 
to ground-water monitoring that were able to detect ground-water 
contamination, consideration must be given to site-specific factors 
such as rock and soil types, hydrogeology, and climate, and to other 
general factors such as equipment availability and cost of operation.
    Commentors focused on alternatives that monitor conditions in the 
unsaturated zone, in the saturated zone (i.e., ground water), in 
surface waters, in the surrounding soils, and in the landfill itself. 
Commentors addressed situations when early detection monitoring used in 
the unsaturated zone would be advantageous over conventional ground-
water monitoring. The Agency believes that in geologic settings where 
ground water lies hundreds of feet below the MSWLF, appropriately 
installed unsaturated zone monitoring devices placed just below the 
MSWLF and above the uppermost aquifer would have the capability to 
detect releases of leachate from the MSWLF before leachate contacts 
ground water. The docket for today's proposal (F-95-AGAP-FFFFF) 
contains several compilations of information on a variety of 
alternative monitoring techniques, including a description of the 
techniques and a discussion of the site-specific conditions that are 
appropriate for each.
     Commentors offered specific ``early detection'' methods, that 
include the measurement of moisture content within the soil or rock 
formations just beneath the landfill by using gypsum blocks, 
geophysical electrical resistivity surveys, and/or lysimeters. For 
further explanation of these methods, the reader is referred to two 
technical background documents: ``Examples of Alternatives to 
Conventional Ground-Water Monitoring Wells at Small, Dry or 

[[Page 40804]]
Remote Landfills'' and ``Subsurface Characterization and Monitoring 
Techniques, Volumes I and II.'' Both documents may be found in the 
docket for this rulemaking (F-95-AGAP-FFFFF).
    While many of these early detection methods, such as gypsum blocks 
and resistivity surveys, do not measure any of the specific chemical 
parameters listed in Appendix I and II of Part 258, the Agency agrees 
with commentors that they are well-established, reliable indicators of 
moisture that are affordable for many small MSWLFs to employ. Detection 
of moisture by an early detection system can be a way to predict 
potential leachate movement from a MSWLF unit. The Agency recognizes 
that the presence of moisture does not necessarily mean that there is 
contamination leaving the MSWLF unit, but detection of moisture can be 
an effective first step in a phased approach to detecting 
contamination. EPA believes that these systems can be cost effective in 
such applications and believes that the States and Tribes can use site-
specific information to determine when to use these systems.
    Commentors were in agreement that a phased approach would be the 
most feasible and cost-effective method of implementation. In such an 
approach, an effective low cost technology could be used to detect 
moisture movement beneath a MSWLF unit. The ground water would be 
sampled to determine ground-water quality in a second phase. Later, 
should ground-water contamination be detected, an expanded monitoring 
system would be employed to provide greater detail on the nature and 
extent of contamination.
    The Agency agrees with this approach for implementing the ground-
water monitoring requirements of RCRA Section 4010(c). The Agency 
believes that if low-cost moisture detection devices (such as gypsum 
blocks) were used as the initial monitoring technique and moisture was 
detected beneath or near the landfill, expanded monitoring would be 
implemented to confirm whether an actual release from the landfill had 
occurred or if the moisture detection devices were reacting to 
infiltrating water from another source. One example of an expanded 
monitoring technique for this situation could be the use of small 
diameter sampling tools that are temporarily driven into the ground by 
hydraulically powered hammers to recover subsurface solids, liquids, or 
gases for laboratory analysis.
    In cases where the recovery and analysis of ground water is 
necessary, several commentors pointed out that the Agency should allow 
limited saturated zone monitoring for a narrow set of indicator 
elements and/or parameters in place of the Appendix I constituents. The 
Agency agrees that alternative parameters used in lieu of current 
Appendix I constituents may be appropriate for these facilities on a 
site-specific basis. A further discussion regarding the use of 
alternative parameters may be found in Section IV.B.1 of today's 
preamble.
    Several commentors provided case studies on the use of existing 
agricultural and drinking water supply wells in ground-water 
monitoring. The Agency believes that the use of existing agricultural 
and drinking water supply wells may be acceptable where the wells are 
located so that they detect potential contamination from the MSWLF 
unit. An owner/operator could determine the suitability of existing 
wells for detecting a release by conducting a characterization of the 
site hydrogeology, including analysis of existing well logs.
    For MSWLF units in Alaska, commentors indicated that conditions are 
so unique in the State that alternative monitoring techniques in Alaska 
would not usually be considered appropriate for the 48 contiguous 
States. For example, commentors stated that, in many instances, 
surface-water monitoring would be more appropriate than ground-water 
monitoring. This is because lateral migration of leachate is more 
probable and is of greater concern than migration to ground water, due 
to low permeability subsurface soils and the presence of permafrost in 
some areas. Commentors recommended monitoring surface/subsurface 
temperatures at frozen landfills located in permafrost areas. 
Commentors from Alaska also recommended modifying the frequency of 
ground-water monitoring such that monitoring occurs when leachate and 
water contamination problems are most likely to be detected. The Agency 
believes that conditions in Alaska are so unique that the State 
regulatory authority, once approved, would be in the best position to 
understand the local conditions and corresponding monitoring techniques 
appropriate for those conditions.
2. Comments on 40 CFR 258.50(b), Demonstration of No Potential for 
Migration
    The final MSWLF criteria in 40 CFR part 258 contained two types of 
exemptions from ground-water monitoring: (1) the small landfill 
exemption that was later vacated by the U.S. Court of Appeals and (2) 
an exemption that can be granted by the Director of an approved State 
or Tribe based on a demonstration that there is no potential for 
migration of hazardous constituents from the MSWLF unit to the 
uppermost aquifer during the facility's active life and post-closure 
care period. This no-migration exemption was not vacated by the U.S. 
Court of Appeals decision, and is available to all MSWLFs, regardless 
of size, where authorized by approved State regulations. The 
requirements for this demonstration are established in 40 CFR 258.50(b) 
and call for: (1) ``site-specific field collected measurements, and 
sampling, and analysis of physical, chemical, and biological processes 
affecting contaminant fate and transport'' and (2) ``contaminant fate 
and transport predictions that maximize contaminant migration and 
consider impacts on human health and the environment.''
    In EPA's announcement of the public meetings, the Agency, in 
addition to requesting comments on ground-water monitoring 
alternatives, requested any information on the ability of owners and 
operators of qualifying small MSWLFs to demonstrate no potential for 
migration. Although the Agency was not re-proposing 40 CFR 258.50(b) in 
that request for comment, the Agency was trying to evaluate the extent 
to which Sec. 258.50(b) would accommodate qualifying small MSWLFs. In 
response, commentors indicated that the Agency should establish 
guidance to simplify and streamline this process for small communities. 
Commentors also suggested that the Agency provide guidance on the type 
and quality of data that are necessary to substantiate a ``no-
migration'' demonstration for small landfills located in arid 
locations.
    The Agency believes that the regulatory standard for demonstrating 
no potential for migration should not be changed, and that any variance 
from ground-water monitoring based on this standard should be granted 
only after the site-specific conditions of 40 CFR 258.50(b) are 
satisfied. The Agency plans to issue a technical guidance document to 
provide additional information to assist owners and operators of 
qualifying small MSWLFs in making a demonstration of no-migration, 
where such an exemption is available from approved States and Tribes. 
The Agency plans to make this guidance readily available to qualifying 
small MSWLFS. Additional discussion on the demonstration of no 
potential for migration is contained in the October 9, 1991 Solid Waste 
Disposal Facility Criteria final rule (56 FR 51061). 

[[Page 40805]]

3. Proposal for Extension to General Compliance Date
    As a separate matter in today's proposal, the Agency is requesting 
comment on two alternatives regarding an extension of the general 
compliance date for meeting the criteria in 40 CFR part 258. As noted 
earlier, the Agency has established a separate docket for this aspect 
of today's proposal (docket number F-95-AGDP-FFFFF) and has provided 
only a 30-day comment period. The shorter comment period is necessary 
to allow the Agency to put an extension in place by the time the 
current compliance date expires on October 9, 1995.
    For qualifying small MSWLFs, the general compliance date for 
meeting the requirements of the solid waste disposal facility criteria 
specified in 40 CFR part 258, currently is October 9, 1995. Unless the 
qualifying small MSWLF ceases receipt of waste by this date, the 
qualifying small MSWLF must comply with all of the part 258 regulations 
including location, operation, ground-water monitoring and corrective 
action, closure and post-closure care, and financial assurance.
    This October 9, 1995 compliance date does not apply in several 
circumstances, however. First, the effective date for ground-water 
monitoring for qualifying small MSWLFs located greater than two miles 
from a drinking water intake is October 9, 1996. Second, qualifying 
small MSWLFs are exempt from the design requirements of part 258 unless 
ground-water contamination that can be attributed to that MSWLF is 
discovered. Finally, in a separate rulemaking, the Agency extended the 
effective date for the financial assurance requirements (Subpart G) for 
all MSWLF units, regardless of size, until April 9, 1997 (see 60 FR 
17649, April 7, 1995).
    Since the Agency announced that it was investigating the 
possibility of providing approved States/Tribes with the flexibility to 
allow qualifying small MSWLFs to use alternatives to ground-water 
monitoring, the Agency believes (based on public comments) that a 
number of these MSWLFs have delayed plans for investing resources 
towards compliance with the requirements in 40 CFR part 258 until the 
Agency publishes a final rule governing the use of ground-water 
monitoring alternatives. The Agency believes that qualifying small 
MSWLFs, in determining whether to remain in operation past the general 
compliance date of October 9, 1995, should be able to consider any 
site-specific flexibilities allowed under a final rule on alternatives 
to ground-water monitoring.
    The Agency anticipates publication of a final rule regarding 
ground-water monitoring alternatives by October, 1996. Therefore, as 
part of today's proposed rule, the Agency is proposing to extend the 
general compliance date for qualifying small MSWLFs from October 9, 
1995 to October 9, 1997. This should provide qualifying small MSWLFs 
with sufficient time to come into compliance. Should public comment 
support today's proposal to extend the general compliance date for 
qualifying small MSWLF units, the Agency would publish a final rule for 
the general compliance date extension prior to October 9, 1995. The 
Agency recognizes that time is short for this action and has taken 
steps that will allow the decision to be made prior to October 9, 1995. 
For this reason, the Agency has set a 30-day public comment period for 
the proposed rule changes that relate to extending the compliance date 
and has established a separate public docket (F-95-AGDP-FFFFF) for 
comments on the extension.
    If finalized, qualifying small MSWLF units would not become subject 
to compliance with any of the part 258 requirements until October 9, 
1997. At that time, these MSWLF units must be in compliance with all of 
the part 258 requirements, including the ground-water monitoring (or 
alternative ground-water monitoring) requirements and financial 
assurance requirements. Should a qualifying small MSWLF unit cease 
receipt of waste prior to October 9, 1997, the owner/operator of that 
unit need only comply with the final cover requirements as specified in 
Sec. 258.60(a). The final cover would have to be installed by October 
9, 1998.
    As a result of today's proposal to extend the general compliance 
date for qualifying small MSWLFs from October 9, 1995 to October 9, 
1997, the Agency is proposing to make corresponding changes in the 
regulatory language in 40 CFR part 258. First, Sec. 258.1(d)(3) and 
(e)(4) would be revised to reflect the new compliance date of October 
9, 1997. Second, the definition of ``New MSWLF unit'' under Sec. 258.2 
would be modified to account for the new general compliance date of 
October 9, 1997. Finally, the applicability section under 
Sec. 258.50(e) would be revised by removing paragraphs (1) and (2), 
which allowed for two different effective dates for the ground-water 
monitoring requirements based on the distance of the MSWLF unit to a 
drinking water intake. Today's proposal would create one effective date 
(i.e., October 9, 1997) for ground-water monitoring for all qualifying 
small MSWLFs, regardless of its distance to a drinking water intake. 
The Agency believes that the new proposed effective date will provide 
sufficient time for all qualifying small MSWLFs to comply.
    During development of today's proposal to extend the general 
compliance date for qualifying small landfills to October 9, 1997, the 
Agency received comments that situations existed where another 
extension of the effective date for all of the requirements of 40 CFR 
part 258 may not be appropriate.
    First, the Agency learned that certain qualifying small landfill 
owners/operators have already made arrangements to close their 
facilities and have established alternative means of waste management, 
particularly through the development of regionalized facilities. The 
Agency understands that the establishment of regional commitments 
amongst numerous small communities that heretofore have independently 
managed their own waste, can be a time-consuming and, at times, 
delicate process. The Agency was informed that an extension of the 
general compliance date could undermine these commitments by creating 
an incentive for these owners/operators to reopen their closed 
facilities.
    The Agency also learned that a number of the qualifying small 
landfills closed in advance of the October 9, 1995 compliance date due 
to the expense of compliance. The Agency understands that another delay 
of the general compliance date might serve to penalize those facilities 
that are trying to work within the rules by either deciding to close or 
make other arrangements and reward those communities that have done 
little or nothing. Finally, the Agency was informed that another delay 
of the general compliance date could allow the reopening of poorly 
designed and operated facilities that have already closed in 
anticipation of the October 9, 1995 compliance date.
    The Agency does not have information on the extent to which the 
aforementioned problems may arise should a two-year delay of the 
general compliance date be promulgated. Therefore, the Agency requests 
comment (addressed to docket number F-95-AGDP-FFFFF) on these and any 
other concerns that may result from a two-year delay of the general 
compliance date.
    In addition to soliciting comment on the implications of a two-year 
general compliance date delay, the Agency invites comments (also 
addressed to docket number F-95-AGDP-FFFFF) on an alternative to the 
proposed two-year delay. The alternative approach would 

[[Page 40806]]
maintain a general compliance date for qualifying small landfills of 
October 9, 1995, but would extend the effective date of ground-water 
monitoring and financial assurance until October 9, 1997. Under this 
alternative approach, such an owner/operator that accepts waste after 
October 9, 1995 would have to comply with the location restrictions and 
operating requirements. Should that owner/operator cease receipt of 
waste by October 9, 1997 and place final cover on the landfill by 
October 9, 1998, that facility would be exempt from ground-water 
monitoring. Under this approach, the owner/operator also would be 
exempt from the financial assurance requirements for closure since 
closure would be completed within one year of last receipt of waste. In 
addition, because most of the costs of post-closure care are attributed 
to ground-water monitoring, the Agency also would exempt the owner/
operator from demonstrating financial assurance for the post-closure 
care period. Table I provides a summary of the proposed delay of the 
general compliance date and the alternative approach.

   Table I.--Proposed Approaches for Extending the Effective Dates for Small Landfill Located in Dry or Remote  
                                                    Locations                                                   
----------------------------------------------------------------------------------------------------------------
                                  Requirements effective on                                                     
           Approach                    October 9, 1995             Requirements effective on October 9, 1997    
----------------------------------------------------------------------------------------------------------------
Proposed Approach: Delay of     No requirements take effect..  All requirements take effect.                    
 General Compliance Date.                                                                                       
Alternative Approach: Delay of  All requirements other than    If cease receipt of waste by October 9, 1997:    
 Groundwater monitoring and      groundwater monitoring and     placement of final cover required by October 9, 
 financial assurance.            financial assurance take       1998. [Note: owner/operator exempt from         
                                 effect.                        groundwater monitoring and financial assurance  
                                                                requirements.]                                  
                                                               If continue receipt of waste after October 9,    
                                                                1997: all other requirements take effect,       
                                                                including groundwater monitoring and financial  
                                                                assurance.                                      
----------------------------------------------------------------------------------------------------------------

III. Alternatives to Ground-Water Monitoring

    In addition to reviewing the comments described in section II.C.1 
of this preamble, the Agency conducted a literature review to assess 
the types of equipment and techniques that can function as alternatives 
to the full ground-water monitoring requirements of Part 258. This 
literature may be found in the docket for today's rule (F-95-AGAP-
FFFFF). The following discussion presents a summary of this review. 
While this discussion does not contain an exhaustive description of all 
possible alternatives, it does discuss several of the technologies 
available and in use today for a variety of geological and 
hydrogeological purposes. Based on this literature review, the Agency 
believes that ground-water monitoring well alternatives, such as those 
described in this section, can, on a site-specific basis, detect 
contamination and determine the nature and extent of contamination.
    Alternatives to conventional ground-water monitoring include 
various types of equipment and measurement techniques that are capable 
of recovering physical samples of ground water or soil and are capable 
of detecting changes in subsurface conditions that are indicative of a 
release from a landfill. In general, alternatives to ground-water 
monitoring wells can be placed into two categories depending on the 
type of measurements made and the data collected. One category, 
geochemical alternatives, includes samples of soil, water, rock, or 
other materials for laboratory analysis. A second category, geophysical 
alternatives, involves methods that rely on the measurement of 
electrical properties, such as conductivity or resistivity. Both 
unsaturated zone monitoring and saturated zone monitoring are possible 
with geochemical and geophysical alternatives, depending on the 
particular characteristics of a landfill and the capabilities of the 
alternative chosen.
    Common sampling devices are readily available and may be used for 
collecting geochemical sample material. Hand-held soil samplers can be 
used for sampling at depths of several feet, and power-driven augers 
may be needed to penetrate and sample consolidated subsurface material. 
The use of a rotary drill may be necessary if geochemical samples must 
be collected from relatively great depths. Small diameter sampling 
tools may be pushed into the subsurface with hydraulic equipment for 
the collection of soil or ground-water samples beneath the landfill. 
Small diameter sampling tools are capable of reaching depths of about 
50 feet in loosely consolidated soil or sediment, but are not designed 
to penetrate thick rock formations. During sample collection, 
geochemical samples must be handled and stored to avoid accidental 
sample contamination.
    Under appropriate conditions, soil pore liquid from the unsaturated 
zone may be collected for laboratory analysis. This procedure involves 
a porous cup that is placed into the subsurface and is connected to a 
vacuum-pressure source. The vacuum draws liquid into the cup, and the 
liquid is transported through a tube to the surface where it is 
collected.
    Alternatives that employ geophysical principles generally provide 
an indirect method for detecting contamination. Electrical geophysical 
methods can measure the contrasting electrical properties of subsurface 
features. By injecting an electrical current into the ground with 
electrodes and measuring the resulting potential field, a geophysical 
electrical resistivity survey can delineate conductive contaminant 
plumes, vertical and lateral extent of geological features, and fresh/
salt water interfaces. Electrical resistivity measurements are normally 
correlated with geology from subsurface borings to validate survey 
results.
    Another method relying on geophysical measurements involves 
moisture detection blocks or electrical resistance sensors. Electrical 
resistance sensors measure the electrical potential between two wires 
spaced a few centimeters apart. The two wires are embedded in a porous 
matrix (typically gypsum-based), forming a block a few inches in 
diameter with wire leads. The blocks are embedded in the subsurface and 
the wires extend to the surface where they are attached to a portable 
resistivity meter. Because the block matrix is porous, soil pore 
liquids can freely enter and leave. When the soils and the electrical 
resistance blocks are dry, the resistance to electrical current flow is 
high, and conversely, when the soil and blocks become wet, a low 
resistance is measured on the meter. These blocks represent a point 

[[Page 40807]]
measurement of soil moisture content. Electrical resistance sensors 
have an effective life span of up to several years, at which time they 
must be replaced.
    A full discussion of other types of equipment and techniques 
possibly serving as alternatives to ground-water monitoring wells is 
beyond the scope of this preamble discussion. For further information 
on alternatives to ground-water monitoring, the reader is referred to 
two technical background documents ``Examples of Alternatives to 
Conventional Ground-Water Monitoring Wells at Small, Dry or Remote 
Landfills'' and ``Subsurface Characterization and Monitoring 
Techniques, Volumes I and II,'' which may be found in docket number F-
95-AGAP-FFFFF for this proposed rule. The Agency is assessing the need 
for additional technical guidance to provide regulators and landfill 
owners and operators with further information regarding ground-water 
monitoring well alternatives.
    In conjunction with the types of alternatives described above and 
in the docket for this rulemaking, the Agency fully supports the use of 
beneficial modified operating practices that may serve to reduce the 
potential for leachate generation in certain situations. Examples of 
such operating practices may include the use of movable covers to 
prevent rainfall infiltration into the working face and body of the 
landfill, early final closure of the landfill cell, and careful 
contouring and drainage design of the final cover to route 
precipitation away from the closed MSWLF unit.

IV. Proposed Rule for Alternatives to Ground-Water Monitoring

A. Overview

    Based on the information contained in docket number F-95-AGAP-FFFFF 
and on comments received at the public meetings, the Agency today is 
proposing to allow alternatives to the full part 258 ground-water 
monitoring requirement for qualifying small MSWLFs, where approved by 
the Director of an approved State or Tribe. This proposed rule covers 
only those MSWLFs meeting the criteria of 40 CFR 258.1(f)(1). The 
Agency estimates that approximately 750 MSWLFs would qualify as a small 
landfill meeting the conditions of Sec. 258.1(f)(1). The Agency 
estimates that between 300 to 500 of these 750 MSWLF units would be 
able to use alternative ground-water monitoring systems; however, the 
final decision to allow the use of alternative ground-water monitoring 
systems would be made by the approved State or Tribe and not by the 
Agency.
    Under today's proposal, all landfills that are not qualifying small 
MSWLFs would be subject to the full ground-water monitoring 
requirements of 40 CFR part 258, subpart E, unless they could 
demonstrate no potential for migration under 40 CFR 258.50(b). This 
proposed rule does not provide any additional exemption or ``no-
action'' alternative to the ground-water monitoring requirements in 40 
CFR part 258. An approved State or Tribe may only waive ground-water 
monitoring requirements if the MSWLF unit meets the conditions 
established in 40 CFR 258.50(b).
    Today's proposal, if finalized, would allow approved States and 
Tribes the flexibility to determine the most appropriate alternative to 
ground-water monitoring for qualifying small MSWLFs based on site-
specific data as long as the alternative ensures the detection of 
contamination. Monitoring may be conducted with a variety of relatively 
low-cost geochemical and geophysical technologies capable of detecting 
contamination and assessing the nature and extent of contamination. 
Some alternatives may detect contamination by directly measuring the 
levels of constituents in ground water, while other alternatives may 
monitor the unsaturated zone or saturated zone for the properties of 
solids, gases, or liquids that are determined to be indicative of 
releases from the MSWLF unit.
    When the Agency proposed the MSWLF criteria in August, 1988, it 
discussed the reasons for requiring ground-water monitoring at all 
MSWLFs, indicating that ground-water monitoring is ``an essential 
measure to ensure protection of human health and the environment * * * 
[and] * * * the most reliable method for determining whether a landfill 
is in compliance with the overall performance standard'' of the MSWLF 
criteria. See 53 FR 33366. The Agency believes that the approach 
adopted in today's proposal, allowing the use of alternative methods to 
detect ground-water contamination (other than monitoring wells), will 
continue to satisfy the statutory requirements in RCRA section 4010(c) 
that ground-water monitoring be implemented at all MSWLFs ``as 
necessary to detect contamination.''
    By providing flexibility to approved States and Tribes to establish 
the best tailored alternative ground-water monitoring regime for each 
qualified small MSWLF, today's proposal is designed to ensure detection 
of contamination in an effective manner that best takes into account 
the numerous, complex characteristics that are encountered on a site-
specific basis. Today's proposal does not exempt qualifying small 
MSWLFs from ground-water monitoring, but instead allows a stepwise 
approach for detecting a release from the landfill that could result in 
ground-water contamination. Today's proposed rule provides the 
flexibility to approved States or Tribes to allow qualifying small 
MSWLFs to use cost-effective screening techniques rather than requiring 
immediate use of a full ground-water monitoring well program. Should 
the screening techniques indicate the possibility of ground-water 
contamination, the approved State or Tribe would then require that 
owners and operators establish more precise techniques that could 
quantify the contamination, including the installation of monitoring 
wells when warranted.
    Alternative ground-water monitoring methods (e.g., monitoring in 
soil or in the unsaturated zone) are intended to detect the escape of 
contaminants from the MSWLF and thereby accomplish the same purpose as 
the ground-water monitoring well program pursuant to 40 CFR 258.51 
through 258.55. While the alternative methods may not always include 
the collection of actual ground-water samples, they will indicate if a 
release from the landfill has occurred, at which point the alternative 
ground-water monitoring method may need to be supplemented by the 
installation of ground-water wells to ascertain whether the ground-
water below the MSWLF has been contaminated.
    The Agency understands that numerous methods and techniques exist 
for sampling and monitoring the saturated and unsaturated zones at 
qualifying small MSWLFs and that existing field methods are often 
refined and new methods are continually being developed. Therefore, the 
Agency believes it would be inappropriate to delineate in today's 
regulations all of the specific alternatives that may be authorized by 
approved States and Tribes. Approved State and Tribal authorities would 
decide which of the available alternatives to ground-water monitoring 
will ensure detection of contamination from the qualifying small MSWLF. 
These decisions will be made in a public forum, since the programs 
administered by States and Tribes provide opportunities for public 
participation during the permit issuance process (40 CFR part 256). 
Thus, members of the public will have an opportunity to comment on the 
selection of an appropriate and reliable 

[[Page 40808]]
alternative ground-water monitoring technique at that time.

B. Proposed Approach for Using Alternatives

1. Consideration of Site-Specific Factors in Selection of an 
Alternative Monitoring Technique
    The Agency believes site-specific factors need to be considered in 
determining which, if any, alternative(s) may be appropriate to detect 
contamination. To ensure that appropriate decisions regarding the use 
of alternatives to ground-water monitoring are made, the Agency 
believes that the following factors should be considered, as warranted 
and appropriate, on a site-specific basis:
     The geology and hydrogeology of the site;
     The impact of manmade and natural features on the 
effectiveness of an alternative technology;
     Precipitation amounts, temperature, and other climatic 
factors; and
     The effectiveness of indicator parameters in detecting a 
potential release from the MSWLF unit.
    The following discussion serves to illustrate, in general, why 
these site-specific factors should be considered when choosing an 
appropriate monitoring alternative.
    a. The geological and hydrogeological characteristics of the site.
    The ground-water monitoring requirements in the final MSWLF 
criteria provide that the number, spacing, and depths of monitoring 
well systems should be determined based upon site-specific technical 
information that must include a site characterization of the geology 
and hydrogeology (40 CFR 258.51(d); see also preamble discussion in 56 
FR 51066). The Agency believes that a similar understanding of the 
geology and hydrogeology also is desirable when deciding whether it is 
appropriate to use alternative monitoring technologies.
    For example, the Director of an approved State or Tribe, when 
considering the use of gypsum blocks as an alternative, would need to 
determine if the presence of shallow ground water could lead to false 
indications of releases from the landfill through seasonal fluctuations 
in ground-water depth and how wet-dry periods and soil chemistry would 
affect the useful life of the gypsum blocks. Additionally, knowledge of 
site geology is important where an owner or operator is considering the 
use of small diameter sampling tools to sample around and beneath the 
landfill for detecting a release. This technology is influenced by the 
ability of the tool to penetrate subsurface materials. For example, 
this technique is most likely to be workable where the geology consists 
of loosely consolidated sediment down to the depth at which samples are 
required.
    b. The impact of manmade and natural features on the effectiveness 
of an alternative technology.
    Manmade and natural features at a particular site may be important 
factors in influencing the capability of an alternative technology to 
detect contamination. For example, as discussed earlier, some 
alternatives may employ the use of electrical geophysical principles to 
provide an indirect method for detecting contamination by measuring the 
contrasting electrical properties of subsurface features to delineate 
contaminant plumes. However, when conducting geophysical electrical 
resistivity surveys, measurement errors may result from electrical 
currents in the ground that interfere with the current being measured. 
Therefore, before employing these surveys, potential subsurface 
interferences should be considered, such as naturally-occurring sulfide 
deposits, the presence of electrical power lines, or buried metal 
objects that are corroding. Additionally, electrical resistivity 
surveys are not recommended for use in paved areas.
    Natural features of a site may impede access necessary to bring 
certain equipment on site. For example, ground penetrating radar 
radiates short pulses of high-frequency radio waves into the ground to 
delineate a leachate plume. The bulkiness of the equipment, however, 
may limit its use in rough and inaccessible terrain.
    c. Climatic factors that may influence the selection, use, and 
reliability of alternative ground-water monitoring procedures.
    The MSWLF owner or operator must have knowledge of precipitation 
amounts in order to determine whether the MSWLF qualifies for today's 
flexibility. In addition, an understanding of the local climatic 
conditions is important in understanding the effectiveness of possible 
alternative monitoring methods. For example, ground penetrating radar 
is best applied in areas with very dry soil conditions. Seismic 
refraction, an alternative technology that relies on an artificial 
seismic source (hammer, controlled explosive charge) to create 
underground seismic waves that are read with a seismograph to delineate 
soils/geology and leachate, might be limited by cold or relatively wet 
weather. Finally, where soil pore liquid is collected from the 
unsaturated zone through the use of porous cup lysimeters, the 
effectiveness of the lysimeter will be hindered in areas where soils 
are frozen, extremely dry, or where subjected to freeze-thaw.
    d. The effectiveness of indicator parameters in detecting a 
release.
    A number of qualifying small MSWLFs may be able to use alternative 
technologies to detect contamination in the unsaturated zone. Where 
these unsaturated zone monitoring methods are allowed by an approved 
State or Tribe, the owner/operator would be monitoring for parameters 
that can be detected by application of that specific technology (e.g., 
gypsum blocks would monitor for the presence of moisture in the zone 
underlying the MSWLF). Some qualifying small MSWLFs, however, may not 
be able to use alternative technologies and may need to use traditional 
monitoring wells to sample and analyze ground water.
    In these situations, the current detection monitoring program in 
Sec. 258.54 requires sampling and analysis at each well for 15 metals 
and 47 volatile organic compounds (VOCs); however, approved States and 
Tribes currently are permitted to (1) replace some or all of the metals 
with geochemical parameters (e.g., ammonia, total dissolved solids) and 
(2) delete any metal or VOC if that constituent is not in or cannot be 
derived from the waste in the landfill.
    At the June, 1994 public meetings, many of the commentors suggested 
that the MSWLF owner/operator should have the flexibility to use a 
shorter, less costly list of monitoring parameters for ground-water 
monitoring wells (primarily geochemical parameters) so long as these 
parameters would indicate a release from the MSWLF. Such flexibility 
would be designed to allow an owner/operator to use geochemical 
parameters in place of both metals and VOCs without having to 
demonstrate that each of the 47 VOCs is not in or cannot be derived 
from the waste in the MSWLF.
    For the reasons discussed earlier in today's preamble (Section 
II.B.1), the Agency believes that approved States and Tribes should 
have the flexibility to establish an alternative list of indicator 
parameters for qualifying small MSWLFs, where appropriate given site-
specific circumstances. These reasons include low precipitation, low 
net infiltration, and great depth to ground water at many of these 
sites, the relatively small amounts of waste received at these MSWLFs, 
and the practicable capability (i.e., economic) considerations of 
qualifying small MSWLFs. The Agency's technical 

[[Page 40809]]
background document (``Examples of Alternatives to Conventional Ground-
Water Monitoring Wells at Small, Dry or Remote Landfills'') and cost 
analysis for today's rule suggests that the use of indicator parameters 
(e.g., Ph, specific conductance, total organic carbon, total organic 
halogen), where appropriate, may be a cost-effective means for owners/
operators of a qualifying small MSWLF to detect contamination from 
their unit. Again, this could be the first step in a phased approach 
that eventually could lead to full ground-water monitoring pursuant to 
the final MSWLF criteria.
    Thus, today's proposal would allow approved States and Tribes to 
permit the use of a set of parameters tailored to a site-specific 
location. The appropriate use of this flexibility again would be tied 
to the site-specific conditions at the particular qualifying small 
MSWLF. For example, the effectiveness of an alternative set of 
parameters depends, in part, on having an adequate understanding of the 
geochemistry of underlying rock, soil, and ground water, to ensure that 
natural variability in concentrations of elements or parameters in the 
ground water can be distinguished from concentrations that are 
indicative of a release from the MSWLF.
    As illustrated in the above discussion, the selection, use, and 
reliability of alternative monitoring technologies or parameters 
depends on a number of site-specific factors. Additional information on 
the types of site-specific factors that should be considered for 
various alternative monitoring techniques and how to apply them may be 
found in the technical background documents entitled ``Examples of 
Alternatives to Conventional Ground-Water Monitoring Wells at Small, 
Dry or Remote Landfills'' and ``Subsurface Characterization and 
Monitoring Techniques, Vols. I and II.''
2. Phased Approach to Alternative Ground-Water Monitoring
    Today's proposal uses an approach that would allow approved States 
or Tribes to implement the proposed ground-water monitoring flexibility 
in phases. Thus, today's proposal would allow approved States or Tribes 
to authorize the use of alternatives to full part 258 ground-water 
monitoring requirements for initially ``detecting'' contamination. If 
contamination is detected, the approved State or Tribe could then allow 
use of further alternatives for ``expanded monitoring'' to assess the 
nature and extent of ``detected'' contamination. Alternatives, or 
combinations of alternatives, could be used for both detection and 
expanded monitoring. Expanded monitoring, however, might require the 
use of conventional ground-water monitoring wells, or other aspects of 
the full part 258 ground-water monitoring requirements.
    As used in this proposed rule, ``detection'' would refer to the 
moment when data, instrument readings, analyses, or other information 
collected by an alternative to full part 258 ground-water monitoring 
requirements indicates a change in surface or subsurface conditions 
that could be caused by a release from an MSWLF. ``Expanded 
monitoring'' would refer to the steps taken to determine whether the 
``detected'' release is an actual release from the MSWLF and to 
determine the nature and extent of the release.
    Under today's proposal, if expanded monitoring using alternatives 
indicates that a release from the MSWLF unit has contaminated the 
saturated zone, then the owner/operator would be required to install 
ground-water monitoring wells and comply with the full range of ground-
water monitoring requirements of 40 CFR part 258 (Secs. 258.50 through 
258.58). If expanded monitoring indicates that a release from the MSWLF 
unit exists, but has not yet contaminated the saturated zone, the 
Director of an approved State or Tribe would establish a schedule for 
the owner/operator to propose, as necessary, measures to prevent 
further contaminant migration and to remediate contamination in a 
manner that ensures protection of human health and the environment.

V. Role of States and Tribes

    Section 4005(c) of RCRA requires that each State (or Tribe) adopt 
and implement a ``permit program or other system of prior approval and 
conditions'' adequate to assure that each facility that may receive 
household hazardous waste or small quantity generator waste will comply 
with the revised MSWLF criteria. The statute also requires each State 
(or Tribe) to adopt and implement a permit program not later than 18 
months after promulgation of EPA's final criteria (October 9, 1991).
    The issue of whether Tribes should be approved to administer 
programs under RCRA Subtitle D is about to be proposed generically as 
part of the State and Tribal Implementation Rule (STIR). The Agency is 
seeking comment on the issue of Tribal permit program approval as part 
of the STIR and not as part of today's proposed rule. References to 
potential Tribal approvals in today's proposed rule are being made to 
be consistent with the STIR proposal.
    The Agency believes that an approved State or Tribal permit program 
plays an important role in the proper implementation of today's rule to 
allow alternative ground-water monitoring requirements. Approved State 
or Tribal permit programs provide opportunities for public 
participation during the permit issuance process, at which time 
alternative ground-water monitoring procedures would be considered.
    The STIR proposal will establish adequacy determination 
requirements and procedures for State and Tribal MSWLF permit programs, 
including submission of an MSWLF permit program application. The 
statute, however, does not require that the STIR be in place before EPA 
assesses the adequacy of any State or Tribal program. In fact, while 
the EPA has not yet promulgated the STIR, the Agency has already 
reviewed and approved over 40 State programs.
    The STIR proposal also will include procedures for submitting 
revised applications for State and Tribal program adequacy 
determinations, should a State or Tribe revise its permit program after 
it has been deemed adequate. Program revision may be necessary when the 
pertinent Federal statutory or regulatory authority or relevant 
guidance changes, or when responsibility for the State or Tribal 
program is shifted within the lead agency or to a new or different 
State or Tribal agency or agencies. Final promulgation of today's 
proposed changes to part 258 may require revision to a State's or 
Tribe's permit program application, as well.
    The statute does not establish any mandatory timeframes for 
revising approved programs, submitting revised applications, or re-
examining adequacy determinations. Schedules for States and Tribes to 
submit revised applications to the Regional Administrator, where 
needed, are to be negotiated by the State or Tribal Director and the 
Regional Administrator. This arrangement should minimize potential 
disruption to on-going program activities.
    States and Tribes may receive approval of their permit programs 
prior to the final promulgation of today's rule and later elect to 
adopt the revised regulatory language regarding alternatives to ground-
water monitoring. These States and Tribes should work with their 
respective Regional EPA offices as they proceed to revise their permit 
programs.

[[Page 40810]]


VI. Consideration of Issues Related to Environmental Justice

    The Agency believes that this proposed rule, if finalized, would 
not have a disproportionately high and adverse environmental or 
economic impact on any minority or low-income group, or on any other 
type of affected community. Rather, the Agency believes that this 
rulemaking will bring the cost of ground-water monitoring to an 
affordable level for some eligible communities that otherwise would 
have to bear the cost of full ground-water monitoring under 40 CFR part 
258. As a result, the Agency believes that this rule will enable some 
minority and/or low-income communities to be served by a local 
landfill, and will reduce the potential for open burning and illegal 
dumping. Because this rule would reduce the financial impacts of 
ground-water monitoring, such communities may be able to allocate some 
funding to other priority issues affecting their local environments.

VII. Impact Analysis

A. Executive Order 12866

    Under Executive Order 12866, EPA must determine whether a 
regulatory action is significant. A significant regulatory action is 
defined by Executive Order 12866 as one that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or rights and obligations or recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
Executive Order 12866.
    Pursuant to the terms of the Executive Order, it has been 
determined that this rule is a ``significant regulatory action'' 
because it raises novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order. Changes made in response to OMB suggestions will 
be documented in the public record.
    The Agency estimated the annual effect on the economy by comparing 
the costs of alternatives to ground-water monitoring with the costs of 
full ground-water monitoring. The Agency estimates the national annual 
costs of baseline ground-water monitoring requirements at qualifying 
small facilities to range from $7.2 million to $26.6 million per year. 
National annual costs of the lowest-cost alternative range from $1.3 
million to $4.4 million per year, resulting in a $5.9 million to $22.2 
million savings over baseline ground-water monitoring requirements. 
Actual regulatory savings from this proposal are likely to be less 
because site-specific factors and/or State regulatory decisions may 
preclude the use of the lowest cost alternative. Because appropriately 
selected alternatives to ground-water monitoring will be able to detect 
contamination, the Agency anticipates that there will be no decrease in 
environmental benefits as a result of the proposed rule. The full cost 
analysis may be found in the docket (F-95-AGAP-FFFFF) to this 
rulemaking.
    For estimating costs of alternatives to ground-water monitoring, 
the Agency selected several alternatives for cost modeling purposes. 
These alternatives include: (A) collection and analysis of ground-water 
samples from existing drinking water/agricultural wells and springs; 
(B) collection of ground-water samples from monitoring wells and 
analysis for a reduced list of constituents; (C) annual sampling and 
analysis of geologic (solid/liquid) materials from the unsaturated 
zone; (D) collection and analysis of soil gas samples from the 
unsaturated zone; (E) performing an electrical resistivity survey, and; 
(F) installing moisture-detection gypsum blocks.
    The lowest cost alternative differed depending on the size and the 
remaining life of the landfill. In most cases, the lowest-cost 
alternatives involved unsaturated zone monitoring techniques. It is 
also important to note that for this analysis the Agency assumed that 
no contamination occurred or was detected. If contamination is 
detected, further analysis is required and the cost savings over 
baseline ground-water monitoring requirements would be reduced, or even 
eliminated.

B. Regulatory Flexibility Act

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires an 
agency to prepare, and make available for public comment, a regulatory 
flexibility analysis that describes the impact of a proposed or final 
rule on small entities (i.e., small businesses, small organizations, 
and small governmental jurisdictions). No regulatory flexibility 
analysis is required if the head of an agency certifies the rule will 
not have significant economic impact on a substantial number of small 
entities.
    The proposed amendment to 40 CFR part 258 would reduce the 
regulatory burdens of the part 258 criteria, thereby imposing no 
additional economic impact to small entities. Therefore, in accordance 
with 5 U.S.C. 605(b), I hereby certify that this rule, if promulgated, 
will not have a significant adverse economic impact on a substantial 
number of small entities (as defined by the Regulatory Flexibility 
Act).

C. Paperwork Reduction Act

    The Agency has determined that there are two reporting requirements 
associated with today's proposed rule. Under this proposal, MSWLF 
owners/operators subject to these provisions are required to report to 
the Directors of approved States and Tribes: (a) the nature and extent 
of any contamination detected, and (b) proposed corrective measures to 
prevent further contamination or to remediate contamination. These 
reporting requirements will not cause any additional burden over 
existing similar requirements of 40 CFR part 258; they are merely 
different because they are generated by alternative monitoring 
programs. These requirements have been submitted for approval to the 
Office of Management and Budget (OMB) under the Paperwork Reduction 
Act, 44 U.S.C. 3501 et seq.
D. Executive Order 12875

    Under Executive Order 12875, Federal agencies are charged with 
enhancing intergovernmental partnerships by allowing State and local 
governments the flexibility to design solutions to problems the 
citizenry is facing. Executive Order 12875 calls on Federal agencies to 
either pay the direct costs of complying with Federal mandates or to 
consult with representatives of State, local, or tribal governments 
prior to formal promulgation of the requirement. The executive order 
also relates to increasing flexibility for State, Tribal, and local 
governments through waivers.
    For this rulemaking, the Agency met with representatives of State 
and local governments, and other members of the regulated community, to 
provide them with an opportunity to present the Agency with information 
regarding the costs of monitoring ground water at qualifying small 
MSWLFs, and on any cost-effective alternatives to full part 258 ground-
water monitoring requirements. The extent of the Agency's consultation 
with affected parties is discussed earlier in this preamble. Through 
this consultation 

[[Page 40811]]
with State and local governments and members of the regulated 
community, the Agency believes that it has complied with the 
requirements of Executive Order 12875, and that this proposed rule will 
not lead to an unfunded Federal mandate. In fact, this proposal is 
expressly designed to increase the flexibility available to approved 
States and Tribes.

E. Unfunded Mandates

    Under Section 202 of the Unfunded Mandates Reform Act of 1995, 
signed into law on March 22, 1995, EPA must prepare a statement to 
accompany any rule where the estimated costs to State, local, or tribal 
governments in the aggregate, or to the private sector, will be $100 
million or more in any one year. Under Section 205, EPA must select the 
most cost-effective and least burdensome alternative that achieves the 
objective of the rule and is consistent with statutory requirements. 
Section 203 requires EPA to establish a plan for informing and advising 
any small governments that may be significantly impacted by the rule.
    EPA has determined that this rule does not include a Federal 
mandate that may result in estimated costs of $100 million or more to 
either State, local, or tribal governments in the aggregate, or to the 
private sector.

List of Subjects in 40 CFR Part 258

    Environmental protection, Reporting and recordkeeping requirements, 
Waste treatment and disposal.

    Dated: August 3, 1995.
Carol M. Browner,
Administrator.

    For reasons set out in the preamble, part 258 of title 40 of the 
Code of Federal Regulations is proposed to be amended as follows:

PART 258--CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS

    1. The authority citation for part 258 continues to read as 
follows:

    Authority: 42 U.S.C. 6907(a)(3), 6912(a), 6944(a) and 6949a(c); 
33 U.S.C. 1345 (d) and (e).

    2. Section 258.1 is amended by revising paragraphs (d)(3) and 
(e)(4) to read as follows:


Sec. 258.1  Purpose, scope, and applicability.

* * * * *
    (d) * * *
    (3) MSWLF units that meet the conditions of paragraph (f)(1) of 
this section and receive waste after October 9, 1991 but stop receiving 
waste before October 9, 1997, are exempt from all the requirements of 
this part 258, except the final cover requirement specified in 
Sec. 258.60(a). The final cover must be installed by October 9, 1998. 
Owners or operators of MSWLF units described in this paragraph that 
fail to complete cover installation by October 9, 1998 will be subject 
to all the requirements of this part 258, unless otherwise specified.
* * * * *
    (e) * * *
    (4) For a MSWLF unit that meets the conditions for the exemption in 
paragraph (f)(1) of this section, the compliance date for all 
applicable requirements of part 258, unless otherwise specified, is 
October 9, 1997.
* * * * *
    3. Section 258.2 is amended by revising the definition of a ``new 
MSWLF unit'' to read as follows:


Sec. 258.2  Definitions.

* * * * *
    New MSWLF unit means any municipal solid waste landfill unit that 
has not received waste prior to October 9, 1993, or prior to October 9, 
1997 if the MSWLF unit meets the conditions of Sec. 258.1(f)(1).
* * * * *
    4. Section 258.50 is amended by revising paragraphs (a) and (e) and 
by adding paragraph (i) to read as follows:


Sec. 258.50  Applicability.

    (a) The requirements in this subpart apply to MSWLF units, except 
as provided in paragraphs (b) and (i) of this section.
* * * * *
    (e) Owners and operators of all MSWLF units that meet the 
conditions of Sec. 258.1(f)(1) must comply with all applicable ground-
water monitoring requirements of this part by October 9, 1997.
* * * * *
    (i) Directors of approved States and Tribes may allow any MSWLF 
unit meeting the criteria established by Sec. 258.1(f)(1) to use 
alternatives to the ground-water monitoring system prescribed in 
Secs. 258.51 through 258.55 so long as the alternatives will detect 
and, if necessary, assess the nature or extent of contamination from 
the MSWLF unit on a site-specific basis; or establish and use, on a 
site-specific basis, an alternative list of indicator parameters for 
some or all of the constituents listed in Appendix I to part 258. 
Alternative indicator parameters approved by the Director of an 
approved State or Tribe under this section must ensure detection of 
contamination from the MSWLF unit.
    (1) If contamination is detected through the use of any alternative 
to the ground-water monitoring system prescribed in Secs. 258.51 
through 258.55, the MSWLF unit owner or operator must perform expanded 
monitoring to determine whether the detected contamination is an actual 
release from the MSWLF unit and, if so, to determine the nature and 
extent of the contamination. The Director of the approved State or 
Tribe shall establish a schedule for the MSWLF unit owner or operator 
to submit results from expanded monitoring in a manner that ensures 
protection of human health and the environment.
    (i) If expanded monitoring indicates that contamination from the 
MSWLF unit has reached the saturated zone, the owner or operator must 
install ground-water monitoring wells and sample these wells in 
accordance with Secs. 258.51 through 258.55.
    (ii) If expanded monitoring indicates that contamination from the 
MSWLF unit is present in the unsaturated zone or on the surface, the 
Director of an approved State or Tribe shall establish a schedule for 
the owner or operator to submit a description of any necessary 
corrective measures. The schedule shall ensure corrective measures, 
where necessary, are undertaken in a timely manner that protects human 
health and the environment. The proposed corrective measures are 
subject to revision and approval by the Director of the approved State 
or Tribe. The owner or operator must implement the corrective measures 
according to a schedule established by the Director of the approved 
State or Tribe.
    (2) When considering whether to allow alternatives to a ground-
water monitoring system prescribed in Secs. 258.51 through 258.55, 
including alternative indicator parameters, the Director of an approved 
State or Tribe shall consider at least the following factors:
    (i) The geological and hydrogeological characteristics of the site;
    (ii) The impact of manmade and natural features on the 
effectiveness of an alternative technology;
    (iii) Climatic factors that may influence the selection, use, and 
reliability of alternative ground-water monitoring procedures; and
    (iv) The effectiveness of indicator parameters in detecting a 
release.
    (3) The Director of an approved State or Tribe can require an owner 
or operator to comply with the requirements of Secs. 258.51 through 
258.55, where it is determined by the Director that using alternatives 
to ground-water monitoring approved 

[[Page 40812]]
under this subsection are inadequate to detect contamination and, if 
necessary, to assess the nature and extent of contamination.

[FR Doc. 95-19666 Filed 8-9-95; 8:45 am]
BILLING CODE 6560-50-P