[Federal Register Volume 66, Number 88 (Monday, May 7, 2001)]
[Proposed Rules]
[Pages 22971-22983]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-11413]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 144 and 146

[FRL-6975-3]


Underground Injection Control Program--Notice of Proposed 
Determination for Class V Wells

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of Proposed Determination.

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SUMMARY: Today, the Environmental Protection Agency (EPA) is proposing 
a determination for all categories of Class V injection wells not 
included in the final rulemaking on Class V motor vehicle waste 
disposal wells and large-capacity cesspools (64 FR 68546, December 7, 
1999). These include shallow non-hazardous industrial waste injection 
wells, large-capacity septic systems, agricultural and storm water 
drainage wells, and other wells. The Agency proposes that additional 
Federal underground injection control (UIC) regulations are not needed 
at this time to prevent Class V wells from endangering underground 
sources of drinking water (USDWs). The Agency will, instead, implement 
its continuing statutory obligations and use existing authorities under 
the Safe Drinking Water Act to protect USDWs from any threatening 
underground injection activities. This proposed determination is based 
on The Class V Underground Injection Control Study (EPA Document Number 
EPA/816-R-99-014, dated September 1999) and other information that has 
been placed in the public docket for comment.

DATES: EPA will accept public comment, in writing, on the proposed 
determination and the 1999 Class V Study until July 6, 2001. The Class 
V Study can also be found on EPA's Web site at www.epa.gov/safewater/uic/cl5study.html.

ADDRESSES: Send written comments to the UIC Class V, W-98-05 Comment 
Clerk, Water Docket (MC-4101); U.S. Environmental Protection Agency, 
1200 Pennsylvania Ave., NW, Washington, DC 20460. Comments may be hand-
delivered to the Water Docket, U.S. Environmental Protection Agency, 
401 M Street, SW, East Tower Basement, Room 57, Washington, DC 20460.
    Comments: Send one original and three copies of your comments and 
enclosures (including any references). Please submit all references 
cited in your comments. Facsimiles (faxes) can not be accepted. 
Commenters who would like EPA to acknowledge receipt of their comments 
should include a self-addressed, stamped envelope. To ensure that EPA 
can read, understand and therefore properly respond to comments, the 
Agency would prefer that commenters cite, where possible, the 
paragraph(s) or sections in the notice or supporting documents to which 
each comment refers. Commenters should use a separate paragraph for 
each issue discussed.
    Comments may also be submitted electronically to [email protected]. 
Electronic comments must be submitted as an ASCII, WP5.1, WP6.1 or WP8 
file avoiding the use of special characters and form of encryption. 
Electronic comments must be identified by the docket number W-98-05. 
Comments and data will also be accepted on disks in WP 5.1, 6.1, 8 or 
ASCII file format.
    The record for this rulemaking has been established under docket 
number W-98-05 and includes supporting documentation as well as 
printed, paper versions of electronic comments. The record is available 
for inspection from 9 to 4 p.m., Monday through Friday, excluding legal 
holidays at the Water Docket, EB 57, USEPA Headquarters, 401 M., 
Washington, DC. For access to docket materials, please call 202/260-
3027 to schedule an appointment.

FOR FURTHER INFORMATION CONTACT: For technical inquiries, contact Joan 
Harrigan-Farrelly, Office of Ground Water and Drinking Water (mailcode 
4606), EPA, 1200 Pennsylvania Ave, NW, Washington, DC 20460. Phone: 
202-260-7077. For general information, contact the Safe Drinking Water 
Hotline, phone 800-426-4791. The Safe Drinking Water Hotline is open 
Monday through Friday, excluding Federal holidays, from 9:00 a.m. to 
5:30 p.m. Eastern Standard Time.

SUPPLEMENTARY INFORMATION: Affected Entities: Although no new 
regulations are being proposed, this notice applies to owners or 
operators of any type of Class V well that is not a large-capacity 
cesspool or motor vehicle waste disposal well, as described in 40 CFR 
144.81(2) and (16), respectively. The following table lists categories 
and examples of entities that may have such wells. This table is not 
intended to be exhaustive, but rather provides a guide for readers 
regarding entities likely to be affected by or interested in this 
action. Other types of entities not listed in the table could also be 
interested in it. To determine whether your injection well is affected 
by this action, you should carefully examine the applicability criteria 
in 40 CFR 144.1(g). If you have questions regarding the applicability 
of this action to a particular entity, consult the person listed in the 
preceding FOR FURTHER INFORMATION CONTACT section.

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                                                 Examples of entities
                 Category                   potentially affected by this
                                                       action
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Industry and Commerce.....................  Farms, animal feeding
                                             operations, and other
                                             agricultural sites that
                                             drain excess surface or
                                             subsurface water into
                                             wells; sites that have
                                             storm water drainage wells,
                                             facilities operating large-
                                             capacity septic systems, or
                                             nonhazardous waste disposal
                                             wells; facilities that
                                             extract minerals from brine
                                             and then inject the spent
                                             brine underground; mines
                                             that backfill materials
                                             into mine shafts,
                                             pipelines, or other holes
                                             that are deeper than they
                                             are wide; aquaculture
                                             facilities that dispose of
                                             wastewater in underground
                                             wells; solution mines that
                                             use injection wells in the
                                             recovery of minerals from
                                             ore bodies that have
                                             already been conventionally
                                             mined; sites that use
                                             injection wells as part of
                                             aquifer remediation
                                             activities; geothermal
                                             power plants that reinject
                                             fluids into the ground;
                                             facilities that extract
                                             direct heat from geothermal
                                             fluids and then return
                                             those fluids underground;
                                             and sites that use ``open-
                                             loop'' heat pump/air
                                             conditioning systems.
State and Local Government................  Municipalities that use
                                             storm water drainage wells;
                                             publicly owned treatment
                                             works that inject sewage
                                             treatment effluent
                                             underground; State and
                                             local government entities
                                             that inject water
                                             underground for the purpose
                                             of aquifer recharge or
                                             aquifer storage and
                                             recovery.
Federal Government........................  Any Federal Agency that owns
                                             or operates one of the
                                             above entities.
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[[Page 22972]]

Table of Contents

I. Background
    A. Statutory and Regulatory Framework
    B. Requirements Applicable to Class V Wells
    C. History of this Rulemaking
    1. 1987 Report to Congress
    2. 1994 Consent Decree With the Sierra Club
    3. 1995 Proposed Determination
    4. 1997 Modified Consent Decree
    5. 1998 Proposal and 1999 Final Rule
    6. 1999 Class V Study
    D. Scope of Today's Proposed Determination
II. Factors Considered in Making the Proposed Determination
    A. Criteria Proposed in 1995
    B. Public Comments on the 1995 Proposed Approach
    C. Proposed Criteria for Today's Notice
III. Class V Wells Found to Have a Low Potential to Endanger in the 
1995 Proposal
    A. 1995 Proposed Finding
    B. Public Comments on Well Types
    C. 1999 Class V Study
IV. Other Class V Wells
    A. Sewage Treatment Effluent Wells
    1. 1995 Proposed Finding
    2. Public Comments
    3. 1999 Class V Study
    4. Proposed Determination
    B. Mine Backfill Wells
    1. 1995 Proposed Finding
    2. Public Comments
    3. 1999 Class V Study
    4. Fossil Fuel Combustion Waste Report to Congress
    5. Proposed Determination
    C. Storm Water Drainage Wells
    1. 1995 Proposed Finding and 1998 Proposal
    2. Public Comments
    3. 1999 Class V Study
    4. Proposed Determination
    D. Large-Capacity Septic Systems
    1. 1995 Proposed Finding
    2. Public Comments
    3. 1999 Class V Study
    4. Guidelines for Management of Onsite Wastewater Systems
    5. Proposed Determination
    E. Agricultural Drainage Wells
    1. 1995 Proposed Finding
    2. Public Comments
    3. 1999 Class V Study
    4. Concentrated Animal Feeding Operations Proposal
    5. Proposed Determination
    F. Industrial Wells
    1. 1995 Proposed Finding
    2. Public Comments
    3. Subsequent Actions
    4. Proposed Determination
V. Comment Solicitation

I. Background

A. Statutory and Regulatory Framework

    Class V wells are regulated under the authority of Part C of the 
Safe Drinking Water Act (SDWA or the Act) (42 U.S.C. 300h et seq.). The 
SDWA authorizes EPA to protect the quality of drinking water in the 
United States, and Part C specifically mandates the regulation of 
underground injection of fluids through wells. The Agency has 
promulgated a series of underground injection control (UIC) regulations 
under this authority.
    Section 1421 of the Act requires EPA to propose and promulgate 
regulations specifying minimum requirements for effective State 
programs to prevent underground injection that endangers drinking water 
sources. EPA promulgated administrative and permitting regulations, now 
codified in 40 CFR parts 144 and 146, on May 19, 1980 (45 FR 33290), 
and technical requirements in 40 CFR part 146 on June 24, 1980 (45 FR 
42472). The regulations were subsequently amended on August 27, 1981 
(46 FR 43156), February 3, 1982 (47 FR 4992), January 21, 1983 (48 FR 
2938), April 1, 1983 (48 FR 14146), July 26, 1988 (53 FR 28118), 
December 3, 1993 (58 FR 63890), June 10, 1994 (59 FR 29958), December 
14, 1994 (59 FR 64339), June 29, 1995 (60 FR 33926), and December 7, 
1999 (64 FR 68546).
    Section 1422 of the Act provides that States may apply to EPA for 
primary enforcement responsibility to administer the UIC program; those 
States receiving such authority are referred to as ``primacy States.'' 
Where States do not seek this responsibility or fail to demonstrate 
that they meet EPA's minimum requirements, EPA is required to prescribe 
a UIC program for such States by regulation. These direct 
implementation (DI) program regulations were issued in two phases, on 
May 11, 1984 (49 FR 20138) and November 15, 1984 (49 FR 45308). For the 
remainder of this preamble, references to the UIC Program ``Director'' 
mean either the Director of the EPA program (where the program is 
implemented directly by EPA) or the Director of the primacy State 
program (where the State is responsible for implementing the program). 
Also, currently all UIC Programs in Indian Country are directly 
implemented by EPA. Therefore, for the remainder of this preamble, 
references to DI programs include UIC programs in Indian Country.

B. Requirements Applicable To Class V Wells

    The UIC regulations establish five classes of injection wells. 
Class I wells are used to inject hazardous and non-hazardous waste 
beneath the lowermost formation containing an underground source of 
drinking water (USDW) within one-quarter mile of the well bore. Class 
II wells are used to inject fluids associated with oil and natural gas 
recovery and storage of liquid hydrocarbons. Class III wells are used 
in connection with the solution mining of minerals from ore bodies that 
have not been conventionally mined. Class IV wells are used to inject 
hazardous or radioactive wastes into or above a formation that is 
within one-quarter mile of a USDW. (Class IV wells are generally 
prohibited by 40 CFR 144.13.) Class V wells are defined in the 
regulations as any well not included in Classes I through IV.
    Class V wells, other than motor vehicle waste disposal wells and 
large-capacity cesspools, are currently authorized by rule 
(Secs. 144.24(a) and 144.84(a)). Rule authorization expires upon the 
effective date of a permit issued pursuant to Secs. 144.25, 144.31, 
144.33, or 144.34; upon meeting one of the conditions specified in 
Sec. 144.84(b); or upon proper closure of the well as described in 
Sec. 144.82(b). Existing Class V motor vehicle waste disposal wells in 
``ground water protection areas'' and ``other sensitive ground water 
areas'' \1\ are banned with a provision that allows owners and 
operators of such wells to seek a waiver from the ban and obtain a 
permit (Sec. 144.88(b)). New Class V motor vehicle waste disposal wells 
and new and existing large-capacity cesspools were banned nationwide 
(Secs. 144.88(a) and (b)). These new requirements affecting motor 
vehicle waste disposal wells and large-capacity cesspools are minimum 
Federal standards--primacy States may impose more stringent 
requirements.
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    \1\ A ground water protection area is defined in Sec. 144.86(c) 
as a geographic area near and/or surrounding community and non-
transient non-community water systems that use ground water as a 
source of drinking water These areas receive priority for the 
protection of drinking water supplies and States are required to 
delineate and assess these areas under section 1453 of the SDWA. 
Other sensitive ground water areas are defined in Sec. 144.85(g) as 
additional State-defined areas that are critical to protecting USDWs 
from contamination. The other sensitive ground water areas may 
include areas overlying sole-source aquifers; highly productive 
aquifers supplying private wells; continuous and highly productive 
aquifers at points distant from public water supply wells; areas 
where water supply aquifers are recharged; karst aquifers that 
discharge to surface reservoirs serving as public water supplies; 
vulnerable or sensitive hydrogeologic settings, such as glacial 
outwash deposits, eolian sands, and fractured volcanic rock; and 
areas of special concern selected based on a combination of factors, 
such as hydrogeologic sensitivity, depth to ground water, 
significance as a drinking water source, and prevailing land use 
practices.
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    In addition to these provisions, Class V UIC Program Directors have 
many obligations and authorities under the SDWA to ensure the 
protection of USDWs. Specifically, the current regulations subject 
Class V wells to the general statutory and regulatory

[[Page 22973]]

prohibitions against endangerment of USDWs, as well as some specific 
requirements. Under Sec. 144.12(a) and Sec. 144.82(a), owners or 
operators of all injection wells, including Class V injection wells, 
are prohibited from engaging in any injection activity that allows the 
movement of fluid containing any contaminant into USDWs, if the 
presence of that contaminant may cause a violation of any primary 
drinking water regulation under 40 CFR part 141 or may otherwise 
adversely affect human health. Sections 144.12(c), (d), and (e) 
prescribe mandatory and discretionary actions to be taken by the 
Director if a well is not in compliance with Sec. 144.12(a). These 
actions may include requiring the well operator to apply for an 
individual permit, ordering such action as closure of the well to 
prevent endangerment, taking an enforcement action, and/or taking an 
emergency action.
    Owners or operators of Class V injection wells must also submit 
basic inventory and assessment information under Sec. 144.26 and 
Sec. 144.83. In addition, Class V wells are subject to the general 
program requirements of Sec. 144.25 and Sec. 144.84 under which the 
Director may require a permit, if necessary, to protect USDWs. 
Moreover, under Sec. 144.27 and Sec. 144.83, EPA may require owners or 
operators of any Class V well, in EPA-administered programs, to submit 
additional information deemed necessary to protect USDWs. Owners or 
operators who fail to submit the information required under 
Secs. 144.26, 144.27, or 144.83 are prohibited from using their 
injection wells.

C. History of This Rulemaking

1. 1987 Report to Congress
    In accordance with the 1986 Amendments to the SDWA, EPA summarized 
information on 32 categories of Class V wells in a Report to Congress 
entitled Class V Injection Wells--Current Inventory; Effects on Ground 
Water; and Technical Recommendations, September 1987 (EPA Document 
Number 570/9-87-006). This report presents a national overview of Class 
V injection practices and State recommendations for Class V design, 
construction, installation, and siting requirements. These State 
recommendations, however, did not give EPA a clear mandate on what, if 
any, additional measures were needed to control Class V wells on the 
national level. For any given type of well, the recommendations varied 
broadly and were rarely made by more than two or three States. For 
example, the recommendations for septic systems range from further 
studies (3 States) to statewide ground water monitoring (1 State). For 
industrial waste water wells, some States recommended immediate action 
and closure while others recommended monitoring and ground water 
evaluation studies.
2. 1994 Consent Decree With the Sierra Club
    On December 30, 1993, the Sierra Club filed a complaint in the 
United States District Court for the District of Columbia alleging that 
EPA failed to comply with section 1421 of the SDWA regarding 
publication of proposed and final regulations for Class V injection 
wells. The complaint alleged that EPA's then current regulations 
regarding Class V wells did not meet the SDWA's statutory requirements 
to ``prevent underground injection which endangers drinking water 
sources.'' (Complaint, Paragraph 15)
    To resolve the issue, EPA entered into a consent decree with the 
Sierra Club on August 31, 1994. This consent decree required that, no 
later than August 15, 1995, the Administrator sign a notice to be 
published in the Federal Register proposing regulatory action that 
fully discharges the Administrator's rulemaking obligation under 
section 1421 of the SDWA, 42 U.S.C. 300h, with respect to Class V 
injection wells. A final rulemaking on the matter was required to be 
signed by no later than November 15, 1996.
3. 1995 Proposed Determination
    On August 15, 1995, the Administrator signed a notice of proposed 
rulemaking that proposed a regulatory determination on Class V 
injection wells intended to fulfill EPA's obligation under the 1994 
consent decree with the Sierra Club (60 FR 44652, August 28, 1995). In 
this notice, EPA proposed not to adopt additional Federal regulations 
for any types of Class V wells. Instead, the Agency proposed to address 
the risks posed by certain wells using existing authorities and a Class 
V management strategy designed to: (1) Speed up the closure of 
potentially endangering wells, and (2) promote the use of best 
management practices to ensure that other Class V wells of concern do 
not endanger USDWs. Several factors led EPA to propose this approach, 
including: (1) The wide diversity in the types of fluids being 
injected, ranging from high risk to not likely to endanger; (2) the 
large number of facilities to be regulated; and (3) the nature of the 
regulated community, which consists of a large proportion of small 
businesses.
4. 1997 Modified Consent Decree
    Based on public comments received on the 1995 proposal, EPA decided 
to reconsider its proposed approach. Because this reconsideration would 
extend the time necessary to complete the rulemaking for Class V wells, 
EPA and the Sierra Club entered into a modified consent decree on 
January 28, 1997 (D.D.C. No. 93-2644) that extended the dates for 
rulemaking that had been in the 1994 decree. The modified decree 
requires three actions.
    First, by no later than June 18, 1998, the EPA Administrator was 
required to sign a notice to be published in the Federal Register 
proposing regulatory action that fully discharged the Administrator's 
rulemaking obligation under section 1421 of the SDWA with respect to 
those types of Class V injection wells determined to be high risk for 
which EPA did not need additional information. The Administrator was 
required to sign a final determination for these endangering Class V 
wells by no later than October 29, 1999. Thirty-day extensions were 
subsequently granted for both of these deadlines.
    Second, by no later than September 30, 1999, EPA was required to 
complete a study of all Class V wells not included in the first 
rulemaking on endangering Class V injection wells. Based on this study, 
EPA may find that some of these other types of Class V wells also 
endanger USDWs.
    Third, by no later than April 30, 2001, the EPA Administrator was 
required to sign a notice to be published in the Federal Register 
proposing to discharge the Administrator's rulemaking obligations under 
section 1421 of the Safe Drinking Water Act (SDWA) with respect to all 
Class V injection wells not included in the first rulemaking for Class 
V injection wells. The Consent Decree requires that the Administrator 
either (1) propose regulations fully implementing section 1421 with 
respect to all such Class V injection wells, (2) propose a decision 
that no further rulemaking is necessary in order to fully discharge the 
Administrator's rulemaking obligations under section 1421 with respect 
to all such Class V injection wells, or (3) propose regulations fully 
implementing section 1421 with respect to some of these remaining Class 
V injection wells and propose a decision that no further rulemaking is 
necessary in order to fully discharge the Administrator's rulemaking 
obligations under section 1421 with respect to all other Class V 
injection wells not already covered. The Administrator must sign a 
final

[[Page 22974]]

determination for these remaining Class V wells by no later than May 
31, 2002.
5. 1998 Proposal and 1999 Final Rule
    On July 29, 1998 (63 FR 40586), in response to the first action 
required under the modified consent decree with the Sierra Club, EPA 
proposed revisions to the Class V UIC regulations that would add new 
requirements for three categories of Class V wells that were believed 
to endanger underground sources of drinking water. According to this 
proposal, Class V motor vehicle waste disposal wells in ground water 
protection areas (as defined in footnote 1 above) would either be 
banned, or would have to get a permit that requires fluids released in 
those wells to meet the drinking water maximum contaminant levels 
(MCLs) and other health-based standards at the point of injection. 
Class V industrial waste disposal wells in ground water protection 
areas also would be required to meet the MCLs and other health-based 
standards at the point of injection, and large-capacity cesspools in 
such areas would be banned.
    EPA received substantial public input on the 1998 proposal. The 
input included 97 letters from public commenters as well as 
recommendations from the National Drinking Water Advisory Council 
(NDWAC), which formed a Federal Advisory Committee Act (FACA) working 
group to address Class V UIC and Source Water Protection Program 
integration issues. This FACA workgroup met twice in 1999 to discuss 
the proposed Class V regulation. In addition, on May 21, 1999 (64 FR 
27741), the Agency published a notice of data availability (NODA) and 
further request for comment related to the 1998 proposal. A total of 14 
public comment letters were received in response to this request.
    Taking all the public input into account, EPA issued final 
revisions to the Class V UIC regulations on December 7, 1999 (64 FR 
68546). The final rule added new requirements for (1) existing motor 
vehicle waste disposal wells located in ground water protection areas 
delineated for community water systems and non-transient non-community 
water systems that use ground water as a source and in other sensitive 
ground water areas delineated by the States; and (2) new and existing 
large-capacity cesspools and new motor vehicle waste disposal wells 
nationwide. The final rule, however, did not adopt the proposed 
additional requirements for industrial waste disposal wells to meet the 
MCLs and other health based standards at the point of injection. Many 
commenters questioned why the Agency chose to regulate a wide range of 
industries with different disposal practices with one approach. Some 
commenters thought the industrial category was too diverse and types of 
industrial waste streams should be regulated based on their specific 
characteristics and risks. After considering these comments, EPA agreed 
that the industrial category is diverse and represents a variety of 
waste streams that required additional review before deciding on the 
need for additional Federal regulations.
6. 1999 Class V Study
    On September 30, 1999, in response to the second action required 
under the modified consent decree with the Sierra Club, EPA published a 
study of all Class V wells not included in the 1998 proposal (EPA 
Document Number EPA/816-R-99-014). The study consisted of two major 
components: (1) An information collection effort for the remaining 
universe of Class V wells, which was divided into 23 different 
categories for the purpose of analysis; and (2) an ``inventory 
modeling'' exercise to estimate the number of storm water drainage 
wells and large-capacity septic systems, two types of wells that were 
believed to be quite prevalent, but for which adequate inventory 
information was particularly lacking.
    As described in detail in Volume 1 of the final Study report, the 
information collection effort consisted of a comprehensive literature 
search, State and EPA Regional data collection, requests to the public 
for data, and peer review. As part of the State and EPA Regional data 
collection, the Agency distributed nearly 700 questionnaires to EPA 
Regional, State, and local program staff in all 50 States and U.S. 
territories, including staff responsible for Class V well control on 
Indian Lands in EPA Regions 5, 8, 9, and 10. The Agency supplemented 
the information from the questionnaires with follow-up telephone 
interviews and on-site file searches in 11 primacy States, 3 DI States, 
and 2 Regional Offices with DI States. The Agency also supplemented the 
survey results with visits to a number of injection well sites, 
including geothermal electric power well sites in California and food 
processing waste disposal well sites in Tennessee and Maine.
    For the inventory modeling, EPA selected and visited a sample of 99 
census tracts across the nation to collect data on the numbers of storm 
water drainage wells and large-capacity septic systems that exist and 
factors that influence their prevalence. Storm water drainage wells 
were found in 22 of the 99 census tracts visited and large-capacity 
septic systems were found in 88 of the 99 census tracts visited. EPA 
used the data collected from the visits to develop mathematical models 
for predicting the numbers of these wells nationwide.

D. Scope of Today's Proposed Determination

    Today's proposed regulatory determination addresses all of the 
Class V well types not covered by the 1999 final rule, in response to 
the third action required under the modified consent decree with the 
Sierra Club. For the purpose of this notice, these other well types are 
discussed in the following categories that track with the earlier 
proposals described above as well as the categories addressed in the 
Class V Study: Agricultural drainage wells, storm water drainage wells, 
large-capacity septic systems, sewage treatment effluent wells, spent 
brine return flow wells, mine backfill wells, aquaculture waste 
disposal wells, solution mining wells, in-situ fossil fuel recovery 
wells, special drainage wells, experimental wells, aquifer remediation 
wells, geothermal electric power wells, geothermal direct heat wells, 
heat pump/air conditioning return flow wells, saltwater intrusion 
barrier wells, aquifer recharge and aquifer storage and recovery wells, 
subsidence control wells, and industrial wells (including, but not 
limited to, carwash wells, food processing waste disposal wells, 
laundromat wells, and non-contact cooling water wells). These 
categories are the same as the ones defined in the existing regulations 
in 40 CFR Sec. 144.81. However, in some cases the categories have been 
combined or separated to facilitate the discussion of the data and 
rationale used to support this determination. This determination, 
however, does not propose to change the Class V well categories 
currently defined in the UIC regulations to the ones discussed here.
    It is also important to clarify that this notice satisfies the 
Agency's obligations under the modified consent decree with the Sierra 
Club, but it does not end EPA's obligations, requirements, and actions 
to prevent Class V wells from endangering USDWs. As described in 
Section I.B above, UIC Program Directors have many obligations and 
authorities under the SDWA to ensure the protection of USDWs from the 
risks posed by Class V wells. The Agency will continue to fulfill these 
obligations and using existing authorities for all Class V wells 
(Section IV.F.3 below summarizes some of the actions UIC Program

[[Page 22975]]

Directors take for Class V industrial wells using these existing 
authorities). In addition, nothing in this notice precludes a State or 
local government from promulgating requirements more stringent than the 
minimum Federal requirements. Also, today's proposed determination does 
not affect EPA's authority to impose any necessary regulations in the 
future on any of the well types addressed in today's notice.

II. Factors Considered in Making the Proposed Determination

A. Criteria Proposed in 1995

    The Agency proposed two criteria in 1995 for evaluating the 
different categories of Class V wells to determine whether any category 
warranted additional regulation: the potential to endanger USDWs and 
the anticipated effectiveness of additional Federal regulation under 
the UIC program in preventing endangerment to USDWs.
    For wells with a low or no potential to contaminate USDWs, the 
Agency proposed that the then existing regulations provided sufficient 
authorities to handle the few cases where mismanagement of one of these 
wells could create an endangering situation. To assess the need for 
additional UIC regulation for the other wells, the 1995 proposal was 
guided by the following principles:
    (1) Additional Federal UIC regulations are not necessary where 
adequate State or local regulations are already in place,
    (2) Additional Federal UIC regulations are not necessary where the 
Class V wells are not the principal source of endangerment from a 
widespread environmental problem,
    (3) Additional Federal UIC regulations are not necessary where 
endangerments are localized problems, e.g., wells that are found only 
in one or two counties or in one or two States. For these wells, EPA 
will work with the States, if necessary, to bring about better 
controls,
    (4) Additional Federal UIC regulations are not necessary where 
other Federal programs address the endangerment caused by certain Class 
V wells.

B. Public Comments on the 1995 Proposed Approach

    EPA received 57 public comment letters on the 1995 proposal, 
several of which addressed the proposed decision-making criteria 
summarized above. Many comments supported the Agency's proposal to not 
impose more regulations for Class V wells based on these criteria. 
However, EPA also received a number of comments that raised concerns 
about the overall approach, including the above criteria and the 
related rationale proposed for some well types. The opposing comments 
are best represented by nine main points made by the Sierra Club, which 
are addressed in turn below.
    First, the Sierra Club asserted that blanket authorization of Class 
V wells by rule, based on any criteria, violates the SDWA. The basis 
for this comment was the Sierra Club's interpretation that SDWA 
requires EPA to prescribe regulatory standards for State programs. EPA 
disagrees that the Class V regulations violate the SDWA. SDWA section 
1421(b) requires EPA to issue regulations for effective State programs 
to prevent endangerment of drinking water sources by underground 
injection. The statute specifically States that the regulations ``may 
permit a State to authorize underground injection by rule.'' Section 
1421(b)(1)(A). EPA has provided such authority to States for Class V 
regulations; the authorization by rule requirements for such wells 
include requirements for reporting and avoiding endangerment of 
drinking water sources. As discussed in more detail below, EPA has 
found that these requirements are generally effective in preventing 
endangerment from the Class V wells discussed in today's proposed 
determination. Thus, EPA has met the statutory mandate of prescribing 
regulations for ``effective'' State programs ``to prevent * * * 
endangerment'' from Class V UIC wells.
    Second, the Sierra Club stated that continued reliance on the non-
endangerment provision in 40 CFR 144.12 and the authority in 40 CFR 
144.25 to require a permit does not fulfill EPA's statutory duty to 
specify minimum requirements for State UIC programs. EPA disagrees with 
this analysis. The minimum requirements for State UIC Class V programs 
are specified in EPA's regulations; these include reporting and non-
endangerment requirements. While these may not be as specific and 
detailed as the requirements for the other UIC well classes, they are 
nonetheless ``minimum requirements for * * * (State) programs'' as 
required by SDWA section 1421(b). Because these requirements, general 
as they are, have been effective in preventing endangerment from these 
wells, no more is required under the statute.
    Third, the Sierra Club argued that the existence of State or local 
regulations does not justify a decision not to impose more Federal 
regulations. While EPA agrees that the mere presence of State or local 
regulations governing UIC wells does not justify a decision not to 
impose Federal requirements under section 1421(b), such State or local 
regulations may be an important factor in determining the extent of 
``endangerment'' from Class V wells and the ``effectiveness'' of 
additional Federal requirements. For example, as discussed below, in 
determining the extent of ``endangerment'' posed by various Class V 
well types, EPA relied heavily upon actual contamination incidents; 
however, the adequacy of State and local requirements was also a factor 
that helped EPA determine the likelihood of future contamination from 
such wells. Similarly, EPA believes that comprehensive State and local 
regulation of a Class V well type, such as septic systems discussed 
below, may make additional Federal regulation entirely duplicative, if 
not disruptive. Where such regulation exists, further Federal 
regulation may be futile in terms of ensuring ``effective'' State 
programs; rather, Federal efforts may be better focused on 
implementation of and education regarding existing regulations and 
programs than merely adding yet another layer of redundant or 
duplicative requirements. Thus, EPA continues to believe that the 
extent of State and local regulation remains a highly relevant 
consideration in meeting the section 1421(b) mandate. At its core, the 
statute clearly envisions that the UIC program be a State-run program 
and the Federal role is to ensure that existing State UIC programs 
become or remain effective in addressing any endangerments from 
underground injection wells.
    Fourth, the Sierra Club claimed that a decision not to impose 
additional regulations cannot be justified on the grounds that Class V 
wells are not the principal source of endangerment from a widespread 
environmental problem, because partial or incremental solutions are 
better than none at all. In order for this criterion to be valid, the 
Sierra Club asserted that EPA would have to show that additional 
Federal regulations yield a gain of trivial or no value. As noted 
below, EPA has dropped this criterion as a basis for deciding not to 
establish further regulations for Class V wells. However, EPA continues 
to believe that the extent of contamination from Class V wells, based 
on actual incidents of contamination, remains a critical factor in 
determining whether sufficient ``endangerment'' is posed by Class V 
wells to warrant additional Federal requirements.
    Fifth, the Sierra Club argued that EPA cannot decide against 
additional Class V regulations based on a finding that endangerments 
are localized problems. According to the comment, nothing in SDWA 
exempts from regulation endangerments that occur in one or a

[[Page 22976]]

few places, and nothing prevents these localized problems from emerging 
in other areas in the future. While EPA agrees that ``endangerments'' 
that are ``localized'' may still warrant Federal regulation since, as a 
factual matter, most well contamination will endanger only a localized 
area, EPA strongly believes that additional Federal regulation is not 
necessary where the endangerment posed by a particular well type 
appears to be isolated and rare. No amount of Federal regulation (or 
any other regulation) can prevent all contamination; the fact that an 
isolated incident of contamination from a UIC well occurs does not mean 
that the State program for that well is ineffective in preventing 
endangerment. Rather, EPA believes that under Section 1421(b) Federal 
regulations for UIC wells are reserved for situations, such as with 
motor vehicle waste disposal wells (addressed in the December 7, 1999, 
final revised Class V UIC regulations (64 FR 68546)), where existing 
State programs are not generally ``effective'' in preventing 
endangerment from certain well types. With respect to assurance that 
wells may not contaminate in the future, EPA believes that it has a 
continuing obligation under 1421(b) to determine whether additional 
Federal regulation is necessary for any UIC well types. Today's 
proposed determination does not affect EPA's authority to impose any 
necessary regulation in the future on any of the well types addressed 
in today's notice.
    Sixth, the Sierra Club asserted that EPA's duty to regulate under 
SDWA is not removed by other Federal programs that also address Class V 
wells. Moreover, the fact that Federal programs overlap in subject 
matter is no obstacle to regulation, and in many cases, other Federal 
programs do not address the endangerment fully. As discussed below, EPA 
has not used other Federal programs as a criterion for determining 
whether to impose additional UIC requirements in today's notice. 
However, EPA does believe that the existence of other Federal programs 
that address Class V wells may be highly relevant in determining 
whether an ``endangerment'' exists and whether additional SDWA 
regulation would be ``effective'' in addressing that endangerment.
    Seventh, the Sierra Club objected to the proposal that additional 
regulations could not be developed for some Class V well types because 
of diversity in local hydrogeologic conditions or in types of fluids 
injected. According to the Sierra Club, such variability is not grounds 
for a regulatory exemption under SDWA and could be addressed by 
establishing targeted regulations for more narrowly defined 
subcategories of wells. While EPA agrees that such diversity in 
conditions is not in itself a reason for EPA to determine that Federal 
regulations are unnecessary, EPA believes that such diversity may be a 
factor in determining whether additional Federal regulation would 
promote more ``effective'' State programs to address the well type in 
question.
    Eighth, the Sierra Club commented that the existence of large 
numbers of regulated entities and an alleged lack of facility-specific 
data do not justify a decision not to regulate further. In support of 
this comment, the Sierra Club said that the size of a regulated 
community is always workable, and that EPA has an obligation to collect 
the data necessary to perform its rulemaking duties. EPA has not used 
either of the factors Sierra Club mentions as a basis for today's 
proposed determination.
    Ninth, the Sierra Club argued that EPA cannot decide against 
additional regulations for some well types based on the criterion that 
a large proportion of the regulated community is comprised of small 
businesses. Among other points made in support of this argument, the 
Sierra Club stated that SDWA creates no exemption for small businesses 
and that EPA did not show that the burden on small businesses would be 
severe. EPA has not used the type of regulated community as a basis for 
today's proposed determination.

C. Proposed Criteria for Today's Notice

    EPA is proposing today to use the two main criteria proposed in 
1995--potential to endanger USDWs and the anticipated effectiveness of 
additional Federal UIC regulation--to determine whether other 
categories of Class V wells warrant additional regulation. The Agency 
is now better able to apply these criteria using additional information 
gathered from the 1999 Class V Study. Based on the above comments and 
responses, however, the Agency is dropping from consideration some of 
the principles used in 1995.
    The potential to endanger USDWs is by far the more important of the 
two criteria, given the SDWA mandate to ensure non-endangerment. EPA 
evaluated this potential based in large part on the record of 
documented incidents of ground water and other environmental 
contamination caused by the operation of the different well types. 
While the Agency also evaluated the potential for such contamination 
based on such factors as the quality of fluids injected, the 
characteristics of the injection zone, well design and operating 
features, the vulnerability of the wells to spills or illicit 
discharges, and the adequacy of existing State and Federal UIC programs 
for addressing any potentially endangering situations, EPA believes 
that the absence of frequent, widespread, or significant cases of 
actual contamination is compelling evidence of a low potential to 
endanger that does not warrant additional Federal regulation at this 
time.
    EPA considered the anticipated effectiveness of additional Federal 
UIC regulation for only a few well categories for which a sound 
determination could not be based on the potential to endanger alone. In 
evaluating the anticipated effectiveness of additional regulation, EPA 
considered such factors as the degree to which additional Federal UIC 
regulations would simply duplicate existing State programs without 
increasing the ``effectiveness'' of these programs. While the Agency 
also considered the possibility of the UIC program joining forces with 
other existing or emerging programs to achieve greater results in an 
integrated fashion, it did not use the existence of other Federal 
programs that also address Class V wells as a basis for deciding 
against additional UIC regulation. In addition, EPA did not use the 
diversity in conditions, the existence of large numbers of regulated 
entities, the lack of facility-specific data, or the existence of a 
large proportion of small businesses as decision making criteria.

III. Class V Wells Found To Have a Low Potential To Endanger in the 
1995 Proposal

A. 1995 Proposed Finding

    Based on the data available at the time, the Agency proposed in 
1995 (see 60 FR 44652, August 28, 1995) that several types of Class V 
injection wells generally had a low potential to endanger USDWs, 
including: (1) Salt water intrusion barrier wells, (2) subsidence 
control wells, (3) heat pump/air conditioning return flow wells, (4) 
spent brine wells, (5) swimming pool and landslide control wells (i.e., 
``special drainage'' wells), and (6) solution mining wells. This 
finding was based on such factors as good injection quality (e.g., 
comparable to or better than the fluids in the injection zone), 
appropriate well construction and maintenance, injection zone 
characteristics, and existing regulatory oversight. In addition, EPA 
found that the following well types generally had a low-to-moderate or 
moderate potential to endanger: (1)

[[Page 22977]]

Aquifer recharge \2\ and aquifer storage and recovery wells, (2) 
aquifer remediation, (3) geothermal direct heat wells, (4) geothermal 
electric power wells, (5) aquaculture wells, (6) experimental 
technology wells, and (7) in-situ fossil fuel recovery wells. In 
general, EPA found that the fluids injected into these wells were of 
lower quality than those injected into the six types of wells first 
discussed above, but well construction, operation, and maintenance in 
combination with locational factors and existing Federal and State 
programs safeguard against endangerment. In the case of in-situ fossil 
fuel recovery wells, the Agency also noted that no wells of this type 
were known to be operating.
---------------------------------------------------------------------------

    \2\ EPA found that some aquifer recharge wells pose a moderate 
to high threat of USDW contamination when they are operated as dual 
purpose wells that alternately withdraw water for irrigation and 
inject irrigation drainage water. These wells are more similar to 
other agricultural drainage wells and are included below in the 
discussion of agricultural drainage wells.
---------------------------------------------------------------------------

B. Public Comments on Well Types

    In response to the 1995 proposal, EPA received no comments on five 
of these 13 well types: (1) Salt water intrusion barrier wells, (2) 
subsidence control wells, (3) special drainage wells, (4) geothermal 
direct heat wells, and (5) aquaculture wells. EPA received limited 
comments that did not disagree with the Agency's characterization of 
the potential of the wells to endanger USDWs for another five of these 
13 well types: (1) Spent brine return flow wells, (2) solution mining 
wells, (3) aquifer recharge and aquifer storage and recovery wells, (4) 
aquifer remediation wells, and (5) experimental technology wells. Of 
the remaining wells, one commenter disagreed with the Agency's 
characterization of heat pump/air conditioning return flow wells and 
geothermal electric power wells as having a low potential to endanger 
USDWs. The commenter indicated that heat pump/air conditioning return 
flow wells could allow the introduction of contaminants (e.g., 
refrigerants, lead, copper) into ground water and possible cross-
contamination between aquifers. In addition, the commenter indicated 
that electric power geothermal injection wells are ``not innocuous'' 
because high temperatures and contaminants picked up in the power plant 
may degrade ground water. Another commenter indicated that ground water 
in the vicinity of five in-situ fossil fuel recover projects has been 
contaminated.

C. 1999 Class V Study

    The Class V Underground Injection Control Study (EPA/816-R-99-014, 
September 1999) presents additional information about each of these 13 
well types that was collected following the 1995 proposal. The Agency 
believes that this information confirms the findings proposed in 1995, 
although some of the supporting details are new or different. For 
example, in 1995, EPA found that there is little chance that fluids 
injected into spent brine return flow wells (in seven States) would 
reach USDWs because the wells were adequately constructed with multiple 
layers of protection and inject into deep confined formations. The 
Class V Study found that spent brine return flow wells regulated under 
Class V now only occur in two States and that in all cases the wells 
have individual permits and inject below the lowermost USDW. Similarly, 
in 1995 EPA found that salt water intrusion barrier wells have a low 
potential to contaminate USDWs because they generally inject fluids of 
equivalent or better quality than the injection zone fluids. The Class 
V Study found that waters of varying quality are injected into these 
wells, but typically the injected water meets primary and secondary 
drinking water standards. In addition, ground water monitoring and 
associated studies have shown no measurable adverse effects on either 
ground water quality or the health of the population ingesting the 
water when the injectate was treated wastewater effluent.
    Of the 13 well types in this group, the Class V Study identified 
reported contamination incidents associated with the operation of only 
three types. For in-situ fossil fuel recovery wells, the Class V Study 
confirmed the information submitted by a commenter that ground water 
contamination had occurred in the vicinity of in-situ fossil fuel 
recovery operations. The Class V Study also confirmed, however, that no 
wells of this type are known to be in operation. For heat pump/air 
conditioning return flow wells, the Class V Study identified a few 
sites where ground water contamination has been reported. Thus, EPA 
agrees with the commenter who indicated that operation of these wells 
could result in ground water contamination. The available information 
indicates, however, that such occurrences are very rare in light of the 
estimated 35,000 wells of this type in over 40 States. For aquifer 
remediation wells, the Class V Study identified a single reported 
contamination incident that resulted from an equipment failure, but 
confirmed that these wells are controlled as part of Resource 
Conservation and Recovery Act (RCRA), Comprehensive Environmental 
Response, Compensation, and Liability Act (CERCLA), and State 
remediation programs in addition to the UIC program.
    For electric power geothermal injection wells, the Class V Study 
did not identify any reported incidents of USDW contamination, but the 
Class V Study did find that injected fluids at some plants may include 
a mixture of surface water, treated wastewater effluent, and/or storm 
water in addition to geothermal fluids. Thus, there is the potential 
for the injected fluids to contain contaminants not present in the 
geothermal fluids, as indicated by one commenter. The Class V Study 
confirmed, however, that geothermal fluids used for power production 
are not typically of potable quality, and that typical well 
construction, operation, and maintenance are not expected to allow 
fluid injection into unintended ground water zones.
    Based on the information available at this time, including the 
Class V Study, EPA concludes that the 13 wells types discussed in this 
section have a low potential to endanger USDWs. As a result, EPA 
concludes that no additional Federal regulations applicable to these 
wells are needed at this time. Where isolated incidences of 
endangerment occur or are threatened, EPA will use its existing 
authorities to require permitting, closure or corrective action to 
address the endangerment.

IV. Other Class V Wells

A. Sewage Treatment Effluent Wells

1. 1995 Proposed Finding
    EPA found that the overall potential for sewage treatment effluent 
wells to contaminate USDWs was moderate. The Agency also found that the 
potential to endanger USDWs ranged from low to high, in large part due 
to the range in the type of treatment provided prior to injection. 
Specifically, the Agency found that some wells inject clarified 
effluent that has undergone secondary or tertiary treatment and have a 
low potential to endanger USDWs, but effluent that has undergone only 
primary treatment creates a higher potential to contaminate USDWs. 
Further, EPA found that the majority of the wells of concern were 
located in Florida and Hawaii and were being addressed at the State 
level. Based on this information, the Agency proposed that no 
additional Federal regulations were needed at the time for sewage 
treatment effluent wells.

[[Page 22978]]

2. Public Comments
    EPA received only one comment on its 1995 proposal for these wells. 
This commenter asserted that additional Federal regulations were needed 
because only a ``majority'' (and not all) of the wells with a high 
potential to contaminate USDWs were being addressed at the State level.
3. 1999 Class V Study
    The Class V Study shows that more than 95 percent of documented 
sewage treatment effluent wells are located in five States: Arizona, 
California, Florida, Hawaii, and Massachusetts. Individual permits are 
required for the wells in all five of these States and the wells are 
prohibited in some situations (e.g., in ground water protection zones 
in Hawaii). Requirements in other States with sewage treatment effluent 
wells include minimum treatment requirements prior to injection (e.g., 
secondary treatment, compliance with MCLs), compliance with MCLs 
outside the ground water discharge zone (at a designated compliance 
point), individual permits, and/or compliance with specified well 
construction and operating requirements.
    The Study identified approximately 1,700 wells, but only two 
incidents in which ground water contamination was attributed to the 
injection of treated sewage effluent through a Class V well. One of 
these incidents occurred more than 25 years ago. Nutrient enrichment of 
surface waters, with resulting algal blooms, has also been reported in 
off-shore waters near some sites where effluent injection occurs in 
some coastal areas in Florida and Hawaii. This issue is receiving 
considerable research and regulatory attention. For example, EPA, the 
U.S. Geological Survey, the National Oceanic and Atmospheric 
Administration, the Florida Department of Environmental Protection, the 
University of South Florida, the University of Miami, the Florida Keys 
National Marine Sanctuary, and several other organizations have 
conducted studies to evaluate the impacts of sewage disposal, including 
the injection of sewage treatment effluent in Class V wells, on 
offshore water quality. These studies suggest that the operation of 
sewage treatment effluent wells and other disposal practices in the 
Florida Keys can lead to rapid nutrient enrichment and fecal 
contamination of marine waters in the Keys, although the concentrations 
eventually reaching surface waters are greatly diluted. To combat this 
problem, Florida currently requires sewage treatment effluent wells to 
be individually permitted and to meet primary drinking water standards 
at the point of injection. In addition, owners or operators of sewage 
treatment effluent wells in Monroe County, which encompasses the Keys, 
are required as part of the Class V operating permit application to 
provide reasonable assurance that operation of their wells will not 
cause or contribute to a violation of surface water quality standards.
4. Proposed Determination
    Based on the information available at this time, including the 
Class V Study, EPA concludes that sewage treatment effluent wells have 
a low potential to endanger USDWs due to a combination of factors. 
These factors, which may vary from well to well, include good injection 
quality, well construction and maintenance, and existing regulatory 
oversight. The most pressing documented problem--injectate migration 
and contamination of offshore water and coral reefs in the Florida 
Keys--is already being studied by many researchers and addressed at 
both the Federal and State levels. The incidence of contamination from 
these wells has also been rare. Thus, EPA proposes that no additional 
Federal regulations applicable to these wells are needed at this time. 
The Agency will use its existing permitting and enforcement authorities 
as necessary to prevent any sewage treatment effluent wells from 
endangering USDWs.

B. Mine Backfill Wells

1. 1995 Proposed Finding
    In 1995, EPA found that mine backfill wells, in general, had a 
moderate potential to contaminate USDWs. This finding was in part based 
on the fact that injected slurries had the potential to react with acid 
mine water to mobilize potential ground water contaminants. However, 
USDWs interconnected with, and therefore potentially affected by the 
mine backfill activities, were generally of moderate to poor quality. 
In addition, mine backfill injection had been shown to improve overall 
ground water quality in some situations, even when contaminants were 
released from the injected slurry. The 1995 proposed finding also 
recognized that most backfill wells were regulated under State water 
quality or mining programs in addition to the UIC program. Based on 
these considerations, EPA proposed that additional Federal regulations 
for these wells were not needed at the time to ensure the protection of 
USDWs.
2. Public Comments
    Several comments on the 1995 proposal were supportive of EPA's 
determination that no additional UIC regulations were needed and 
specifically discussed the adequacy of current requirements for 
backfilling of hard rock mines. No commenters directly opposed the 
proposed determination, although one commenter indicated that they 
favored the addition of a general permit authority.
3. 1999 Class V Study
    The Study documented that mine backfill wells are used in many 
mining regions of the country to inject a mixture of water, sand, mill 
tailings, or other materials such as coal combustion ash and flue gas 
desulfurization sludge into underground mines. Information collected 
and compiled in the Study is consistent with the information available 
in 1995 that showed that ground water quality within a mine is often 
poor (e.g., due to acid mine drainage) and that backfill wells are just 
one of many possible sources (including natural sources) of ground 
water contamination. No incidents of contamination directly 
attributable to these wells were reported, and in some cases 
information shows that backfill wells have negligible or positive 
effects on ground water quality. In other cases, however, backfill 
material has been shown to leach contaminants more readily than 
predicted by standard tests and increase contaminant concentrations in 
ground water. The chance that backfill injection will contribute to 
ground water contamination is highly dependent on site conditions, such 
as site hydrogeology, mine mineralogy, backfill characteristics and 
injection practices.
    More than 90 percent of the documented mine backfill wells reported 
in the Study are located in four States that have primacy for the Class 
V portion of the UIC wells. Two of these States require individual 
permits for the wells while the other two States issue permits by rule 
as long as USDW endangerment does not result. Other States regulate 
mine backfill wells by rule authorizing them and implementing existing 
UIC authorities, or by issuing general (or area) permits or individual 
permits.
4. Fossil Fuel Combustion Waste Report to Congress
    Also in 1999, EPA issued a Report to Congress on Wastes from the 
Combustion of Fossil Fuels (EPA 530-S-99-010). Based on the findings of 
this report, comments and additional data

[[Page 22979]]

received, and additional analysis of the available information, the 
Agency made a regulatory determination in May 2000 (65 FR 32214) that 
additional regulations under Subtitle D of RCRA and/or possibly 
modifications to existing regulations established under Surface Mining 
Control and Reclamation Act (SMCRA) authority are warranted when coal 
combustion wastes are used to fill surface or underground mines (i.e., 
minefilled). In making this determination, the Agency explained that 
although placement of coal combustion waste in a mine has not been 
documented to cause increased damage to ground water, minefilling is an 
increasingly common practice that could present a danger to human 
health and the environment under certain circumstances (e.g., placement 
directly into the ground water). EPA found that available information 
indicates that if the chemistry of the mine relative to the chemistry 
of the coal combustion wastes is not properly taken into account, the 
addition of coal combustion wastes to certain environmental settings 
can lead to an increase in hazardous metals (e.g., arsenic) released 
into the environment. The Agency also noted that management of coal 
combustion wastes in the presence of acid-generating pyritic wastes has 
caused metals to leach from the combustion wastes at much higher levels 
than are predicted by leach test data for coal combustion wastes when 
strongly acidic conditions are not present. Further, the Agency noted 
that a recent study of cement kiln dust showed that placement directly 
in contact with ground water led to substantially greater release of 
hazardous metal constituents than EPA predicted would occur when not 
placed in ground water.
    In addition, EPA explained that there are few States that operate 
comprehensive programs that specifically address the unique 
circumstances of minefilling, making it more likely that damage to 
human health or the environment could go unnoticed. In particular, the 
Agency found that government oversight has not ``caught up'' with 
recent and rapidly expanding minefilling of coal combustion wastes and 
that serious gaps exist in State programs, such as a lack of adequate 
controls and restrictions on unsound practices, e.g., no requirement 
for ground water monitoring and no control or prohibitions on waste 
placement in the aquifer.
5. Proposed Determination
    Based on the information available at this time, EPA concludes that 
mine backfill wells generally have a low potential to endanger USDWs 
because no incidents of contamination directly attributable to these 
wells were reported, and in some cases information shows that backfill 
wells have negligible or positive effects on ground water quality. As 
discussed above, however, injection of coal combustion wastes may 
threaten ground water under some circumstances. The Agency has recently 
initiated efforts to improve its understanding of this potential threat 
to ground water and address it for both surface and underground 
minefilling (including underground injection) using the regulatory 
authorities of RCRA and/or SMCRA. As a result, EPA proposes not to 
develop any additional Federal UIC regulations applicable to mine 
backfill wells at this time. Rather, the Agency will continue to assess 
any potential endangerment of USDWs by individual mine backfill wells 
and address any such potential endangerment with existing permitting 
and enforcement authorities and any new requirements to be developed 
under RCRA and/or SMCRA.

C. Storm Water Drainage Wells

1. 1995 Proposed Finding and 1998 Proposal
    EPA found that storm water drainage wells had a moderate potential 
to endanger USDWs. This proposed finding considered the fact that storm 
water can acquire contaminant loads from streets, roofs, landscaped 
areas, industrial areas, and constructions sites. The most significant 
concern identified was wells located in industrial settings (e.g., near 
loading docks, process areas) where chemical spills may occur and enter 
the well unless a physical barrier (e.g., berm) is present to contain a 
spill. In other settings, EPA found that storm water would normally not 
contain contaminants in concentrations that exceed drinking water 
standards. Moreover, available contamination studies did not show that 
area-wide degradation of ground water quality had resulted from storm 
water drainage wells.
    Based on this information, EPA proposed not to develop any 
additional Federal UIC regulations applicable to storm water drainage 
wells at that time. However, recognizing the potential concern 
associated with such wells at industrial sites, EPA proposed to 
categorize storm water drainage wells located in industrial settings as 
industrial wells unless an adequate barrier is in place to prevent 
spilled materials from entering the well. According to the 1995 
proposal, these so-called ``industrial drainage'' wells were to be 
addressed with additional guidance as well as outreach and education to 
make sure they did not endanger USDWs.
    The Agency extended this proposal for storm water drainage wells at 
industrial sites as part of the 1998 proposal. Specifically, the Agency 
proposed that industrial drainage wells would be subject to the 
proposed new requirement to meet MCLs at the point of injection, just 
like other kinds of Class V industrial wells. This new proposal, 
however, was predicated on EPA's ability to establish a clear and 
enforceable definition of an industrial drainage well that would be 
subject to the new requirement, versus a storm water drainage well at 
an industrial site that would not be subject to the new requirement 
because it had a low potential to receive chemical spills or highly 
contaminated drainage. The 1998 proposal specifically requested public 
comment on the practicality of making this distinction (see 63 FR 
40598, July 29, 1998 for more detail).
2. Public Comments
    No comments were received that opposed EPA's 1995 proposed 
determination that additional Federal UIC regulations were not needed 
for storm water drainage wells. However, some commenters opposed EPA's 
approach to considering wells located in industrial settings to be 
industrial wells. In particular, some commenters asserted that 
industrial settings and acceptable barriers were not sufficiently well 
defined. Other commenters indicated that the barrier requirement was 
impractical, that sound management practices are at least as effective 
as physical barriers in preventing contaminants from reaching a well, 
and that storm water wells at service stations should not be regulated 
as industrial wells.
    In response to the 1998 proposal, some commenters supported EPA's 
revised proposal that wells receiving storm water in industrial 
settings be considered storm water wells (rather than industrial wells) 
even if they had the potential to receive waste due to leaks, drips, 
and spills as long as the amounts of waste would be insignificant. 
Other commenters maintained that wells with the potential to receive 
any leaks, drips, or spills should be considered industrial wells. Many 
commenters expressed concern about EPA's proposed distinction between 
storm water drainage wells and industrial drainage wells at industrial 
facilities and requested that EPA make the distinction between the two 
types of wells more clear and definitive. Still

[[Page 22980]]

other commenters requested that all storm water wells be subject to 
stringent requirements, with some commenters specifically suggesting a 
ban of storm water drainage wells in source water protection areas, in 
part due to their vulnerability to spills and misuse.
3. 1999 Class V Study
    The Study identified approximately 71,000 documented storm water 
drainage wells and estimated that approximately 248,000 may actually 
exist in the United States. Despite this large number of wells 
operating throughout the country, the Study reports only 12 documented 
incidents of contamination of ground water by storm water drainage 
wells; eight of these incidents were associated with storm water 
drainage from industrial/commercial activities. In addition, the Study 
identified storm water drainage wells as potentially vulnerable to 
spills or illicit discharges if they are located near roadways, parking 
lots, and areas of commercial/industrial activities. However, these 
problems are more hypothetical than actual. About half of the States 
with storm water drainage wells permit these wells by rule while the 
other half have individual permit/registration systems. Four States ban 
the wells entirely or under certain circumstances. In addition, when 
industrial stormwater drainage wells are found, EPA Regions or States 
require them to either close or get a permit.
4. Proposed Determination
    Based on the information available at this time, including the 
Class V Study, EPA concludes that additional Federal regulations under 
the UIC program are not required at this time. The available 
information indicates that endangerment of USDWs by storm water 
drainage wells occurs only rarely, considering the relatively small 
number of contamination incidents relative to the number of wells known 
or estimated to exist. Although there is a concern that storm water 
drainage wells may be vulnerable to spills and illicit discharges, 
there is little evidence that this is a problem other than at 
industrial facilities. Even at industrial facilities, endangerment of 
USDWs by storm water drainage wells does not appear to be a widespread 
problem but instead is limited to isolated, relatively infrequent 
incidents. To a much lesser extent, this proposal is also based on the 
impracticality (as supported by public comments on the 1998 proposal) 
of distinguishing between industrial drainage wells that might be 
subject to additional regulations and other storm water drainage wells 
that would not. Therefore, any attempt to target a new regulation to 
the few isolated cases that might pose an endangerment would also 
capture and impose needless burdens on many wells that are not a 
concern. EPA believes the situation would be better addressed by 
continuing to use existing authorities to close or otherwise address 
problem wells on an individual basis to prevent these wells from 
endangering USDWs. In doing so, the Agency will coordinate the efforts 
of the UIC program with those of the National Pollutant Discharge 
Elimination System (NPDES) storm water program.

D. Large-Capacity Septic Systems

1. 1995 Proposed Finding
    EPA found that large-capacity septic systems (LCSSs) do not pose a 
significant national problem. This assessment is different from that 
contained in the 1987 Report to Congress on Class V Injection Wells 
(EPA 570/9-87-006) because that report considered systems that receive 
industrial and commercial wastes whereas LCSSs as now defined receive 
only sanitary waste.\3\ In addition, the Report to Congress considered 
single-family systems, which are not within the scope of the UIC 
program. EPA also found in 1995 that insufficient spacing between 
systems was the major cause of ground water contamination from LCSSs. 
The Agency concluded that land use planning and siting requirements 
tailored to local conditions by State and local authorities, coupled 
with additional UIC program implementation and technical guidance, was 
the most effective approach to protecting USDWs.
---------------------------------------------------------------------------

    \3\ The Agency considers systems that do not receive solely 
sanitary waste to be industrial wells rather than LCSSs.
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2. Public Comments
    Some commenters supported EPA's proposed finding that no additional 
UIC regulations were required as well as the Agency's plan to issue 
guidance, while some other commenters argued that LCSSs should be 
excluded from UIC regulation altogether. Other commenters supported 
additional Federal regulations, including suggestions that EPA require 
ground water elevation monitoring, establish monitoring provisions and 
management strategies to address loss of system integrity, require 
individual permits, or ban septic systems in sensitive ground water 
areas. One commenter argued that State and local programs with tailored 
standards to prevent ground water endangerment by LCSSs were not in 
place.
3. 1999 Class V Study
    The Study identified three documented cases of ground water 
contamination incidents attributable to LCSSs and 24 documented cases 
of system failures where the extent of resulting ground water 
contamination, if any, is not known. Thus, the prevalence of 
contamination cases appears to be low relative to the number of systems 
in use (approximately 350,000), even if there are additional LCSS 
failures (which seems likely) that were not identified during the 
Study. The Study also found that LCSSs are used nationwide and that 
although all States have applicable regulations, the regulations vary 
from stringent siting, construction, and operating requirements to 
general construction permitting. State regulations also vary with 
respect to the size standard definitions that determine which systems 
are considered ``large'' (and thus subject to UIC regulation) rather 
than small.
4. Guidelines for Management of Onsite Wastewater Systems
    On October 6, 2000, EPA published for review and comment a draft of 
its Guidelines for Management of Onsite/Decentralized Wastewater 
Systems and an outline for a guidance manual that will supplement the 
guidelines addressing all sizes of septic systems. EPA's development of 
these guidelines was described in the Clean Water Action Plan released 
by the Agency in 1998 and is in response to State agency reports that 
septic systems, which are predominantly single family septic systems, 
constitute the third most common source of ground water contamination 
because systems have failed due to inappropriate siting or design or 
inadequate long-term maintenance. Thus, the purpose of the guidelines 
is to raise the quality of management programs, establish minimum 
levels of activity, and institutionalize the concept of management for 
all sizes of septic systems. The guidelines apply to both existing and 
new septic systems and to systems of any size for residential and 
commercial wastewater treatment and disposal. The guidelines contain a 
set of model programs that rely on coordinating responsibilities and 
actions among the State, tribal or local regulatory agency, the 
management entity or service provider, and the system owner.
5. Proposed Determination
    Based on the information available at this time and the actions the 
Agency is

[[Page 22981]]

currently undertaking to improve the performance of septic systems 
through the development of management guidance, EPA concludes that 
additional Federal regulations under the UIC program are not required 
at this time. This conclusion is reached because (1) based on the 
results of the Class V Study, actual contamination from these wells is 
relatively isolated and (2) an additional layer of Federal UIC 
requirements, placed on top of existing State and local LCSS 
regulations, would not be effective in further preventing endangerments 
from these wells. EPA believes that the development and implementation 
of management guidance is a preferable approach to development of 
additional UIC requirements for preventing endangerment of ground water 
by LCSSs for several reasons. First, the approach is comprehensive--it 
address all types and sizes of septic systems, of which LCSSs regulated 
under the UIC program are just one small part. Second, use of an 
integrated and comprehensive approach for all septic systems will 
expedite implementation and avoid potential confusion or disruption of 
current programs that have varying approaches to distinguishing 
``large'' from ``small'' systems. Third, the management guidance 
approach is designed to accommodate regional differences in 
environmental sensitivity and the level of management activities needed 
to achieve water quality and public health protection. Finally, this 
approach avoids the additional administrative burden on States and the 
regulated community that would come from additional Federal UIC 
regulations that the Agency believes are not likely to be effective in 
preventing endangerments from these wells. This is chiefly due to the 
fact that existing State and local requirements are already more 
specifically tailored to local hydrologic conditions than new Federal 
UIC regulations could be. Adding another layer of generalized Federal 
requirements will not add any real safe guards in protecting 
underground sources of drinking water. EPA believes that any gap in 
environmental protection associated with these wells is caused by a 
lack of effective and proper implementation, not a lack of standards; 
thus additional standards would not address this problem. Rather, EPA's 
approach is to spur better implementation of existing standards.

E. Agricultural Drainage Wells

1. 1995 Proposed Finding
    Based on the 1987 Report to Congress, EPA found that agricultural 
drainage wells have a high potential to contaminate USDWs because they 
may inject sediment, nutrients, pesticides, metals, and pathogens. The 
Agency also found that additional Federal UIC regulations for 
agricultural drainage wells were not likely to be effective in 
protecting USDWs in agricultural areas due to the wide range of 
contamination sources such as fertilizer and pesticide application and 
land use practices. In addition, EPA found that agricultural drainage 
wells were concentrated primarily in three States. As a result, EPA 
concluded that it could best achieve the goal of protecting USDWs from 
contamination by agricultural drainage wells by assisting States in 
promoting the use of best management practices (BMPs) that are best 
suited to local conditions and to addressing potential ground water 
contamination sources in a holistic fashion. EPA proposed not to 
develop any additional Federal UIC regulations applicable to 
agricultural drainage wells and instead to rely on technical guidance, 
existing authorities (such as requiring a permit under 40 CFR 144.12), 
and other Agency programs targeted at improving the quality of 
agricultural runoff.
2. Public Comments
    One commenter opposed EPA's finding that no new UIC regulations 
were necessary or appropriate given other EPA reports that indicated 
agricultural runoff was a widespread threat to drinking water quality 
in the midwest. Another commenter indicated that EPA's finding failed 
to meet the requirements of the SDWA because the Agency may choose not 
to regulate only if it demonstrates that injection will not endanger 
USDWs. Two commenters indicated that the guidance document that EPA 
proposed to develop to facilitate implementation of BMPs should be 
developed with State input and public review and comment.
3. 1999 Class V Study
    The Class V Study identified four documented cases of ground water 
contamination clearly attributable to agricultural drainage wells. Two 
of these cases occurred in the 1970's. In addition, six other studies 
point to agricultural drainage wells as contributing to the more 
general problem of nitrate contamination in ground water in 
agricultural areas. The Study also found that the potential for 
agricultural drainage wells to endanger USDWs is highest when the wells 
are located near animal waste management areas such as manure lagoons 
and/or in settings where manure is land applied; however, no actual 
cases of contamination involving spills or leaks from manure lagoons 
migrating through agricultural drainage wells are known to have 
occurred. In addition, the Study found that more than 95 percent of the 
approximately 1,100 documented wells in the country are concentrated in 
just five States (Idaho, Iowa, Ohio, Texas, and Minnesota). Four of 
these five States require individual permits/authorizations or ban the 
wells under certain circumstances. For example, Iowa bans agricultural 
drainage wells in areas that have anaerobic lagoons or earthen manure 
storage structures, and Minnesota bans wells that inject into an 
aquifer (i.e., saturated zone).
4. Concentrated Animal Feeding Operations Proposal
    On December 15, 2000, the EPA Administrator signed proposed 
revisions to the NPDES permit regulations and effluent guidelines that 
would address the water quality impacts of manure, wastewater, and 
other process waters generated by concentrated animal feeding 
operations (CAFOs) (66 FR 2960, January 12, 2001). The proposal, which 
is a step in implementing the EPA and U.S. Department of Agriculture's 
Unified Strategy for Animal Feeding Operations developed in March 1999, 
would apply to as many as 39,000 CAFOs across the country. According to 
alternate definitions that were proposed, CAFOs would be defined as 
facilities that maintain anywhere from 300 to more than 1,000 ``animal 
units'' in confinement, including cattle, swine, turkeys, chickens, 
horses, sheep or lambs, and ducks. The rule would apply to production 
areas at CAFOs (animal confinement areas, manure storage areas, raw 
material storage areas, and waste containment areas) and areas under 
the control of CAFO owners or operators where manure is land applied.
    The proposal explicitly recognizes and addresses the risk of animal 
wastes from CAFOs migrating through agricultural drainage wells into 
ground water that has a direct hydrologic connection to surface waters. 
Specifically, the proposal would prohibit the application of animal 
wastes within 100 feet of sinkholes and intake structures or 
agricultural well heads. EPA requested comment on the presence of such 
features in crop land and the extent to which the 100-foot setback 
around such features would interfere with the land application of 
manure.
    The proposal includes several other features that would have the 
effect of protecting ground water quality and reducing the endangerment 
associated

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with agricultural drainage wells at or near CAFOs. For example, for 
animal confinement and manure storage areas, the proposal would adopt a 
zero discharge requirement with no overflow allowance for swine, veal, 
and poultry CAFOs, would require routine inspections of the production 
area to ensure that wastewater and manure handling and storage are 
functioning properly, and would require proper closure of manure 
storage units. The proposal also would require CAFO operators to land 
apply manure at proper agronomic rates, which would reduce the 
potential for excess manure and associated contaminants to migrate 
overland or underground into agricultural drainage wells.
5. Proposed Determination
    Although there are potential concerns associated with agricultural 
drainage wells, EPA does not believe the available information on 
contamination incidents and the potential for these wells to endanger 
USDWs suggests the need to develop additional Federal UIC requirements 
at this time. The incidence of contamination from these wells is very 
low. States where the vast majority of agricultural drainage wells are 
known to exist are already implementing effective programs. The CAFO 
proposal, if promulgated, would take a significant step to address the 
greatest remaining threat identified for these wells: the potential for 
contamination from large manure lagoons and from the land application 
of manure. EPA will continue to look for situations where these and 
other threats might exist and, if found, take action on a case-by-case 
basis to prevent endangerment using existing authorities.

F. Industrial Wells

1. 1995 Proposed Finding
    In the 1995 proposal, industrial wells were defined to include 
Class V motor vehicle waste disposal wells and other kinds of wells 
used to inject industrial and commercial waste that did not fall into 
one of the other proposed categories of Class V wells. Using this broad 
definition, the 1995 proposal found that some types of industrial wells 
may have a high potential to endanger USDWs. The Agency, however, 
proposed that these wells are best addressed using existing authorities 
and that additional Federal UIC regulations to protect USDWs would be 
inappropriate. One of the main reasons for this position was the 
diversity in the types of fluids being injected into industrial wells, 
which would make it difficult to establish one set of national minimum 
requirements. Another important reason was a lack of facility-specific 
data that EPA would need to develop a tailored regulatory approach 
appropriate to the different kinds of industrial wells and their 
respective degrees of endangerment.
2. Public Comments
    While EPA received some comments supporting the 1995 proposal for 
industrial wells, such as from State agencies that believed they 
already had sufficient authority and knowledge to address these wells, 
a number of commenters opposed the 1995 approach. Much of the 
opposition came from the Sierra Club. As discussed in Section II.B 
above, the Sierra Club stated that the diversity of fluids injected 
into industrial wells is not grounds for a decision against additional 
Federal regulations and could be addressed by establishing targeted 
regulations for more narrowly defined subcategories of wells. The 
Sierra Club further commented that EPA has an obligation to collect any 
additional facility-specific data deemed necessary to perform its 
rulemaking duties.
3. Subsequent Actions
    Based on public comments on the 1995 proposal, and in accordance 
with the 1997 modified consent decree with the Sierra Club, EPA issued 
a revised proposal in 1998. This revision proposed to separate motor 
vehicle waste disposal wells from the other kinds of industrial wells 
considered in the 1995 notice, and to either ban motor vehicle waste 
disposal wells in ground water protection areas or to require such 
wells to be permitted. Other wells left in the industrial well 
category, when located in ground water protection areas, would be 
required to meet MCLs and other health-based standards at the point of 
injection, according to the 1998 proposal. The 1999 final rule expanded 
this approach for motor vehicle waste disposal wells to include Other 
Sensitive Ground Water Areas as defined by the States. A final decision 
on how to address the remaining industrial wells was delayed, mainly 
because of continuing public concern that the industrial well category 
was still too diverse and included many kinds of wells that do not 
endanger USDWs. Some State and EPA Regional UIC programs also 
maintained that additional Federal regulations for industrial wells 
were unwarranted because the programs already had ample authority and 
were already adequately addressing these wells.
    Therefore, instead of finalizing the 1998 proposal for other kinds 
of industrial wells not addressed by the 1999 rule on motor vehicle 
waste disposal wells, EPA decided to conduct further review to decide 
whether additional Federal regulations are needed. This additional 
review consisted of the following three components, which are 
summarized in turn below: (1) public notice and review of additional 
information on contamination incidents potentially attributable to 
Class V industrial wells; (2) more detailed study of four specific 
types of Class V industrial wells; and (3) evaluation of Class V UIC 
program activities to address industrial wells using existing 
authorities.
    The NODA EPA published on May 21, 1999 (64 FR 27741) presented 
additional information on, among other topics, contamination incidents 
potentially attributable to Class V industrial wells. That information 
was collected as part of the Class V UIC Study, which was still ongoing 
at the time, as well as from separate file searches conducted at the 
EPA Region II and Region VIII offices. All of the information was 
placed in EPA's Water Docket for public review when the NODA was 
published. As noted by several commenters on the NODA, and as 
determined upon review by EPA, these reported incidents do not provide 
compelling evidence of significant problems caused by Class V 
industrial wells. The primary limitation is that most of the incidents 
are associated with illegally operating Class IV (i.e., shallow 
hazardous waste) injection wells, which are generally prohibited under 
the current UIC regulations, rather than Class V wells. EPA recognizes 
that this problem can be addressed by greater enforcement of the 
existing ban of Class IV wells and does not necessarily require 
additional Federal regulations on Class V industrial wells. Moreover, 
many of the potential contamination incidents included in the NODA are 
more than 10 years old and not relevant to today's practices, are based 
on anecdotal information or secondary references of questionable 
credibility, involve contamination that remained below levels of 
concern, are not clearly linked to Class V wells as opposed to other 
pollutant sources, and involve only possible contamination rather than 
actual documented contamination. Altogether, information from the Class 
V Study placed in the NODA revealed only three documented cases of 
contamination that site-specific reports clearly attribute to the 
operation of Class V industrial wells, and two of these

[[Page 22983]]

cases were discovered in the 1970's and one was discovered in 1987. 
This is a very low contamination frequency considering the thousands of 
wells estimated to be operating, and it does not suggest a widespread 
current problem that warrants new Federal regulations.
    The Class V Study also included a more detailed examination of four 
specific types of Class V industrial wells: (1) Wells used to dispose 
of washwater at carwashes that do not clean undercarriages or engines; 
(2) wells used to dispose of food preparation-related wastewater and 
food processing equipment or facility wash down water; (3) wells used 
to inject fluids from laundromats where no onsite dry cleaning is 
performed or where no organic solvents are used for laundering; and (4) 
wells used to inject noncontact cooling water that contains no 
additives and has not been chemically altered. EPA does not believe the 
information compiled for these well types, presented in Volumes 4, 6, 
8, and 22, respectively, of the Class V Study report, demonstrates a 
potential to endanger that warrants additional regulation. For example, 
across all four well types, the Study found only one documented 
contamination incident (involving a lobster processing/holding facility 
in Maine) and two possible contamination incidents (involving carwashes 
in Hawaii). There remains concern about some wells at carwashes being 
vulnerable to spills or illicit discharges when an attendant is not 
onsite, but the Study did not find evidence showing that such problems 
associated with carwash wells are actually occurring and warrant the 
development of new UIC regulations.
    EPA also reevaluated how Class V UIC primacy States in their 
regions address industrial wells using existing authorities. Class V 
primacy States have demonstrated the ability to use existing 
authorities to take some form of action to ensure that Class V 
industrial wells do not endanger USDWs. Some States have an outright 
ban of industrial wells while other States require permits for 
industrial wells. Some States ban the wells under some situations but 
permit them under others. When a previously unidentified industrial 
well is discovered, the existing UIC programs investigate the situation 
and decide on the best way to address it, which may include requiring 
the well to close or get a permit, depending on site-specific 
conditions and threats. Such follow up investigation and action is 
usually taken immediately after a Class V industrial well is 
discovered, or as soon thereafter as possible given a State's workload 
relative to available resources to implement the Class V portion of 
their UIC program. Limited resources, not regulatory authorities, 
appears to be the primary factor that would constrain a primacy State 
from taking immediate action to address the risks posed by Class V 
industrial waste disposal wells. Therefore, an additional layer of 
Federal regulation would providing no real safe guards for protecting 
underground sources of drinking water.
    In States where EPA directly implements the Class V portion of the 
UIC program, the EPA Regional Offices always address endangering Class 
V wells as soon as they are identified, as a matter of routine policy 
under the existing UIC regulations and authorities. Although the exact 
nature and timing of actions required vary from one Regional Office to 
the next, the DI programs typically require endangering industrial 
wells to close or get a permit, and require site investigation and 
remediation in response to any contamination that may have occurred. 
Such actions have been found to send a strong message to owners or 
operators of uninventoried industrial wells that they too should close 
their wells. EPA also communicates this message officially in outreach 
materials distributed to well owners and operators in DI programs and 
to staff in primacy States for them to use as part of their programs.
4. Proposed Determination
    The 1999 final rule included new stringent regulations targeting 
the subcategory of Class V industrial wells believed to have the 
highest potential to endanger USDWs at the time of the 1995 proposal: 
Motor vehicle waste disposal wells. Further review of the remaining 
types of Class V industrial wells (1) indicates that they have not been 
the source of frequent contamination incidents and (2) confirms that 
existing UIC programs in States where most industrial wells are known 
to exist are already using existing authorities to adequately address 
these wells and protect USDWs. As a result, EPA does not believe there 
is a need to develop additional Federal UIC regulations applicable to 
Class V industrial wells at this time. Instead, the Agency will 
continue to prevent endangerment from individual wells using existing 
authorities. This effort will include enforcing the existing 
prohibition of Class IV wells to prevent accidental or illicit abuses 
of Class V industrial wells and continuing to provide technical 
assistance and support to State UIC programs, where needed, to make 
sure these wells are being adequately controlled. EPA also will explore 
additional opportunities to communicate UIC requirements and 
obligations to certain industry sectors in association with the 
effluent guideline program implemented under the Clean Water Act.

V. Comment Solicitation

    EPA is soliciting public comment on the underlying data and 
rationale supporting this proposed determination that additional 
Federal UIC regulations are not needed at this time to prevent Class V 
wells from endangering underground sources of drinking water. This 
proposed determination is based on The Class V Underground Injection 
Control Study (EPA Document Number EPA/816-R-99-014, dated September 
1999) and other information that has been placed in the public docket 
for comment. Also, EPA is soliciting any new data or information 
relevant to the findings in this proposed determination and the Class V 
injection well types it addresses.

    Dated: April 30, 2001.
Diane C. Regas,
Acting Assistant Administrator for Water.
[FR Doc. 01-11413 Filed 5-4-01; 8:45 am]
BILLING CODE 6560-50-U