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perform a mid-course review to
December 31, 2004. EPA proposes to
approve this revised commitment.
8. Summary of Conclusions and
Proposed Action
This revision is being proposed under
a procedure called parallel processing,
whereby EPA proposes rulemaking
action concurrently with the State's
procedures for amending its regulations.
If the proposed revision is substantially
changed in areas other than those
identified in this document, EPA will
evaluate those changes and may publish
another notice of proposed rulemaking.
If no substantial changes are made other
than those areas cited in this document,
EPA will publish a final rulemaking on
the revisions. The final rulemaking
action by EPA will occur only after the
SIP revision has been adopted by New
Jersey and submitted formally to EPA
for incorporation into the SIP.
EPA is proposing to approve New
Jersey's proposed SIP revision
submitted on January 31, 2003. This
submittal revises New Jersey's 1996,
2005, and 2007 motor vehicle emission
inventories and 2005 and 2007 motor
vehicle emissions budgets using
MOBILES, modifies the planned date to
complete the State's mid-course review
to December 31, 2004, and updates the
general conformity emissions budgets
for McGuire Air Force Base. New Jersey
has demonstrated that its revised 1-Hour
Attainment Demonstration SIP for the
Northern New Jersey NAA and the
Trenton NAA continues to demonstrate
attainment with the revised MOBILES
inventories.
9. Statutory and Executive Order
Reviews
Under Executive Order 12866 (58 FR
51735, October 4, 1993), this proposed
action is not a "significant regulatory
action" and therefore is not subject to
review by the Office of Management and
Budget. For this reason, this action is
also not subject to Executive Order
13211, "Actions Concerning Regulations
That Significantly Affect Energy Supply,
Distribution, or Use" (66 FR 28355, May
22, 2001). This proposed action merely
proposes to approve state law as
meeting Federal requirements and
imposes no additional requirements
beyond those imposed by state law.
Accordingly, the Administrator certifies
that this proposed rule will not have a
significant economic impact on a
substantial number of small entities
under the Regulatory Flexibility Act (5
U.S.C. 601 et seq.). Because this rule
proposes to approve pre-existing
requirements under state law and does
not impose any additional enforceable
duty beyond that required by state law,
it does not contain any unfunded
mandate or significantly or uniquely
affect small governments, as described
in the Unfunded Mandates Reform Act
of 1995 (Public Law 104-4).
This proposed rule also does not have
tribal implications because it will not
have a substantial direct effect on one or
more Indian tribes, on the relationship
between the Federal Government and
Indian tribes, or on the distribution of
power and responsibilities between the
Federal Government and Indian tribes,
as specified by Executive Order 13175
(65 FR 67249, November 9, 2000). This
action also does not have Federalism
implications because it does not have
substantial direct effects on the States,
on the relationship between the national
government and the States, or on the
distribution of power and
responsibilities among the various
levels of government, as specified in
Executive Order 13132 (64 FR 43255,
August 10, 1999). This action merely
proposes to approve a state rule
implementing a Federal standard, and
does not alter the relationship or the
distribution of power and
responsibilities established in the Clean
Air Act. This proposed rule also is not
subject to Executive Order 13045
"Protection of Children from
Environmental Health Risks and Safety
Risks" (62 FR 19885, April 23, 1997),
because it is not economically
significant.
In reviewing SIP submissions, EPA's
role is to approve state choices,
provided that they meet the criteria of
the Clean Air Act. In this context, in the
absence of a prior existing requirement
for the State to use voluntary consensus
standards (VCS), EPA has no authority
to disapprove a SIP submission for
failure to use VCS. It would thus be
inconsistent with applicable law for
EPA, when it reviews a SIP submission,
to use VCS in place of a SIP submission
that otherwise satisfies the provisions of
the Clean Air Act. Thus, the
requirements of section 12(d) of the
National Technology Transfer and
Advancement Act of 1995 (15 U.S.C.
272 note) do not apply. This proposed
rule does not impose an information
collection burden under the provisions
of the Paperwork Reduction Act of 1995
(44 U.S.C. 3501 et seq.).
List of Subjects in 40 CFR Part 52
Environmental protection, Air
pollution control, Hydrocarbons,
Intergovernmental relations, Oxides of
Nitrogen, Ozone, Reporting and
recordkeeping requirements, Volatile
organic compounds.
Authority: 42 U.S.C. 7401 etseq.
Dated: April 22, 2003.
Jane M. Kenny,
Regional Administrator, Region 2.
[FR Doc. 03-10999 Filed 5-2-03; 8:45 am]
BILLING CODE 6560-50-P
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 146
[FRL-7488-7]
Underground Injection Control
Program—Revision of Underground
Injection Control Requirements for
Class I Municipal Wells in Florida;
Notice of Data Availability
AGENCY: Environmental Protection
Agency.
ACTION: Notice of data availability.
SUMMARY: On July 7, 2000, the
Environmental Protection Agency (EPA)
proposed revisions to the Underground
Injection Control (UIC) regulations that
would allow for continued wastewater
injection by existing Class I municipal
wells that have caused or may cause the
movement of fluid into or between
underground sources of drinking water
(USDWs) in specific areas of South
Florida. The revisions would provide
owners and operators of such wells with
an alternative for compliance with the
existing UIC regulations, which prohibit
such fluid movement, by allowing them
to continue using their wells provided
the injection does not endanger USDWs.
Also in 2000, in a separate but related
initiative, Congress directed EPA to
conduct a relative risk assessment of
four management options for treated
municipal wastewater in South Florida:
deep (Class I municipal) well injection,
ocean disposal, surface discharge, and
aquifer recharge. A separate document
in today's Federal Register announces
the availability and summarizes the
findings of this relative risk assessment
required by Congress. In this notice of
data availability, EPA solicits public
comment on how information on deep
(Class I municipal) well injection in the
relative risk assessment should inform
the Agency's action on the July 7, 2000,
proposed rule.
DATES: Comments on this notice of data
availability must be in writing and
either postmarked or received by the
docket by July 7, 2003.
ADDRESSES: Send written comments to:
Nancy H. Marsh, U.S. Environmental
Protection Agency, Region 4, 61 Forsyth
Street, SW., Atlanta, GA 30303-8960.
Comments may be submitted
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23667
electronically to marsh.nancy@epa.gov.
For additional information see
Additional Docket Information in the
SUPPLEMENTARY INFORMATION section of
this Federal Register document.
FOR FURTHER INFORMATION CONTACT: For
inquiries, contact Nancy H. Marsh,
Ground Water & UIC Section, U.S.
Environmental Protection Agency,
Region 4, 61 Forsyth Street, SW.,
Atlanta, GA 30303-8960 (phone: 404-
562-9450; E-mail:
marsh.nancy@epa.gov) or Howard
Beard, Office of Ground Water and
Drinking Water, U.S. Environmental
Protection Agency, EPA East, 1200
Pennsylvania Ave., NW., Mail Code
4606M, Washington, DC, 20460 (phone:
202-564-3874; E-mail:
beard.howard@epa.gov) or 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 a.m.
to 5:30 p.m. eastern daylight-saving
time.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. General Information
A. Who are Regulated Entities?
B. Additional Docket Information
C. Will There Be Public Meetings?
II. Background
A. Definition of Class I Municipal Wells
B. Proposed Rule for Class I Municipal
Wells in Florida
C. Relative Risk Assessment of
Management Options for Treated
Municipal Wastewater in South Florida
III. Findings of the Relative Risk Assessment
Pertaining to Deep Well Injection
A. What Level of Treatment and
Disinfection is Provided for Deep Well
Injection?
B. What Stressors Remain (After
Treatment) That May Be a Concern for
Deep Well Injection?
C. What Exposure Pathways Are (Or May
Be) of Significance for Deep Well
Injection?
D. What is the Overall Estimate of Risk for
Deep Well Injection?
E. What Are the Important Data or
Knowledge Gaps for Deep Well
Injection?
IV. Relevance of These Findings for the Final
Rule for Class I Municipal Wells in
South Florida
A. Additional Wastewater Treatment Prior
to Injection
B. Feasibility of a Hydrogeologic
Demonstration
C. Some Deep Wells May Have Been
Misclassified as Class I, When They Are
Actually Class V
V. Solicitation of Comment
I. General Information
A. Who Are Regulated Entities?
This notice is limited in application
to the owners and/or operators of
existing deep (Class I) underground
injection wells that inject domestic
wastewater effluent in specific counties
in Florida. The counties are: Brevard,
Broward, Charlotte, Collier, Dade,
Flagler, Glades, Hendry, Highlands,
Hillsborough, Indian River, Lee,
Manatee, Martin, Monroe, Okeechobee,
Orange, Osceola, Palm Beach, Pinellas,
St. Johns, St. Lucie, Sarasota, and
Volusia. Regulated categories and
entities include:
Municipalities and
Private
Category
Local Government
Examples of entities
Class 1 municipal injection wells disposing of domestic wastewater ef-
fluent in certain parts of Florida.
Class 1 municipal injection wells disposing of domestic wastewater ef-
fluent in certain parts of Florida.
This table is not intended to be
exhaustive, but rather provides a guide
for readers regarding entities likely to be
regulated by this action. This table lists
the types of entities that EPA is now
aware could potentially be regulated by
this action. Other types of entities not
listed in the table could also be
regulated by this action. To determine
whether your injection well might be
regulated, you should carefully examine
the applicability criteria in 40 CFR
146.15 of the July 7, 2000, proposed
revisions to the Class I UIC regulations
(65 FR 42234). If you have questions
regarding the applicability of this action
to a particular entity, consult one of the
persons listed in the preceding FOR
FURTHER INFORMATION CONTACT section.
B. Additional Docket Information
When submitting written comments
(see ADDRESSES section) please submit
an original and three copies of your
comments and enclosures (including
any references). The record is available
for inspection from 8 a.m. to 3:30 p.m.
Eastern daylight-saving time, Monday
through Friday, excluding legal
holidays, at the Environmental
Protection Agency, Region 4 Library
(9th Floor), Sam Nunn Atlanta Federal
Center, 61 Forsyth St., SW., Atlanta, GA
30303-8960. For information on how to
access Docket materials, please call
404-562-8190 and refer to the Florida
UIC docket.
C. Will There Be Public Meetings?
EPA plans to have public meetings in
Florida during the comment period.
EPA will announce the dates, times and
locations of those public meetings in a
subsequent Federal Register document.
II. Background
A. Definition of Class I Municipal Wells
Class I injection wells are wells that
inject fluids beneath the lowermost
formation containing, within one-
quarter mile of a well bore, a USDW (40
CFR 144.6(a)). Class I wells can be used
to inject hazardous, industrial, or
municipal wastes. Class I municipal
wells inject treated wastewater from
publicly or privately owned and
operated facilities that treat domestic
wastewater, which is principally
derived from dwellings, business
buildings, and institutions. Domestic
wastewater is commonly referred to as
sanitary wastewater or sewage. Treated
wastewater from industrial facilities,
often controlled through pretreatment
standards, may also be found in this
wastewater. Currently, Class I municipal
wells are located only in the State of
Florida.
B. Proposed Rule for Class I Municipal
Wells in Florida
EPA has established minimum
requirements for Class I municipal wells
and other underground injection
activities through a series of UIC
regulations at 40 CFR parts 144 through
147, developed under the authority of
the Safe Drinking Water Act (SDWA).
These regulations ensure that Class I
municipal wells will not endanger
USDWs by prohibiting the movement of
any contaminant into USDWs.
On July 7, 2000, EPA proposed
revisions to the UIC regulations that
would allow continued wastewater
injection by existing Class I municipal
wells that have caused or may cause
movement of contaminants into USDWs
in specific areas of Florida (65 FR
42234). Continued injection would be
allowed only if owners or operators
meet certain additional requirements
that provide adequate protection for
USDWs. If new requirements are not
promulgated, owners and/or operators
of wells affected by the proposal would
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be required to close their wells and
adopt different wastewater disposal
practices, which could consist of surface
water disposal, ocean outfall, and/or
reuse. Use of these alternative disposal
practices would likely require the
construction of facilities with advanced
wastewater treatment, nutrient removal,
and high-level disinfection.
EPA proposed two primary options
for the additional requirements: Option
1—Facilities must provide advanced
wastewater treatment and high-level
disinfection with a demonstration that
the injectate will not cause a USDW to
exceed any national primary drinking
water regulations in 40 CFR part 141
and other health-based standards (e.g.,
Federal or State health advisories
approved by the UIC Program Director,
if a national primary drinking water
regulation is not available for specific
pollutants); and Option 2—Facilities
must conduct an in-depth hydrogeologic
demonstration that the injection
operation would not cause fluids that
will migrate into the USDW to exceed
any national primary drinking water
regulations in 40 CFR part 141 and other
health-based standards and, if the
demonstration is not successful, must
provide advanced treatment, as
necessary, to ensure that injectate will
not cause a USDW to exceed any
national primary drinking water
regulations in 40 CFR part 141 and other
health-based standards. This second
option also proposed a provision
whereby all facilities qualifying for
authorization to inject under this option
would be required to install advanced
wastewater treatment and high-level
disinfection by 2015. The preamble to
the proposal describes in detail the
history of domestic wastewater injection
in Florida, along with the features of
Florida geology that have allowed some
of that injected wastewater to enter
USDWs. EPA received approximately
1,200 comments on the proposal (the
comment period closed on October 22,
2000). The Agency will address these
comments, along with comments
received in response to this notice of
data availability, as part of the final
action on this rulemaking.
C. Relative Risk Assessment of
Management Options for Treated
Municipal Wastewater in South Florida
As part of EPA's fiscal year 2000
appropriations bill, Congress included
the following provision: "Within
available funds, the conferees direct
EPA to conduct a relative risk
assessment of deep well injection, ocean
disposal, surface discharge, and aquifer
recharge of treated effluent in South
Florida, in close cooperation with the
Florida Department of Environmental
Protection and South Florida municipal
water utilities." Because this directive
came at a time when EPA's work on the
July 7, 2000, proposal was substantially
complete, the Agency decided to
proceed with the proposal and the
relative risk assessment along separate
but converging paths. First, EPA
published and sought comment on the
proposal based on information available
at that time. Second, EPA initiated and
conducted the relative risk assessment
with the intent of using relevant
findings to inform the final rulemaking.
EPA started the relative risk
assessment by working with
stakeholders to develop an appropriate
methodology. The Agency first outlined
a proposed methodology following
standard risk assessment principles and
guidance, such as the "Guide for
Developing Conceptual Models for
Ecological Risk Assessments."a EPA
then held a stakeholders meeting on
March 20, 2001, in Tallahassee, Florida
to discuss the proposed methodology.
The meeting was attended by 17
stakeholders representing municipal
water utilities, regulators, and
community and environmental groups.
Participants offered comments on the
proposed methodology, which EPA
adopted accordingly.
The methodology involved a process
for investigating the four very different
wastewater disposal options: deep well
injection, aquifer recharge, discharge to
ocean outfalls, and discharge to other
(non-ocean) surface water bodies. Each
option has its own specific stressors
(hazards), exposure pathways, receptors,
and effects. Parameters that are relevant
to one particular disposal option are not
necessarily relevant to the remaining
three. Therefore, a strictly quantitative
comparison between the four options
was not possible.
Instead, EPA conducted what is
termed a relative risk assessment to both
assess the risks and allow comparisons.
Individual risk assessments were
completed for each wastewater disposal
option and the risks associated with
each were characterized. The risks and
risk factors identified through each
option-specific disposal option were
then evaluated and described. The
overall comparisons and conclusions
were then presented as relative risk
assessment matrices.
The steps involved in the relative risk
assessment included developing a
Generic Risk Analysis Framework
i Prepared by G. W. Suter H of Oak Ridge National
Laboratory for the U. S. Department of Energy.
Report No. ES/ER/TM-186 issued in May 1996.
Available at http://www.esd.ornl.gov/programs/
ecorisk/tml86.pdf.
followed by conducting analyses of
option-specific conceptual models. Data
from many sources were used to support
the analyses. These sources include the
Florida Department of Environmental
Protection, utilities (and the South
Florida Water Environment Utility
Council), and municipalities in South
Florida. EPA also worked with a panel
of experts both inside and outside of
EPA and from a variety of fields to
review and incorporate data and
information acquired through
exhaustive searches of the relevant
scientific research literature. Risk
characterization for each option
included identifying and describing the
associated risks, their potential
magnitude, and the potential effects on
human and ecological health. The
relative risk assessment then described
and compared risks for all four
wastewater management options.
Finally, the relative risk assessment was
peer reviewed in accordance with the
Agency's Peer Review Handbook.
III. Findings of the Relative Risk
Assessment Pertaining to Deep Well
Injection
The relative risk assessment offers
comparisons of deep well injection,
ocean disposal, surface discharge, and
aquifer recharge of treated municipal
wastewater in South Florida. Findings
related to each of these management
options are highlighted in a separate
notice in today's Federal Register and
presented in greater detail in the relative
risk assessment report. EPA is seeking
comment in sections IV and V below on
how these findings should inform the
final rulemaking on Class I municipal
wells in Florida. To provide background
and context for those following sections,
the remainder of this section
summarizes how the relative risk
assessment addresses five key questions
specifically related to deep well
injection.
A. What Level of Treatment and
Disinfection Is Provided for Deep Well
Injection?
All facilities that manage municipal
wastewater by deep well injection in
Florida are required to provide, at a
minimum, secondary treatment of the
wastewater prior to injection. Secondary
treatment comprises biological removal
of dissolved organic and inorganic
matter, commonly through such
methods as activated sludge and
trickling filter processes. By itself,
secondary treatment does not remove
microorganisms by either disinfection
(through the addition of chlorine, for
example) or filtration.
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23669
Utilities that employ deep well
injection in South Florida must
maintain disinfection capability, but
many do not disinfect treated effluent
prior to injection. For example,
treatment of wastewater that is injected
by Class I municipal wells in Bade and
Brevard Counties consists of secondary
treatment with no disinfection, although
backup disinfection capability is
required. In contrast, in Pinellas County,
wastewater is treated to reclaimed water
standards before being discharged into
Class I municipal wells, because the
Class I wells are used to dispose of
reclaimed water during periods of wet
weather. Reclaimed water standards, as
specified by the State of Florida, include
secondary treatment and a variety of
techniques to address pathogenic
microorganisms, including filtration and
high-level disinfection.
B. What Stressors Remain (After
Treatment) That May Be a Concern for
Deep Well Injection?
"Stressors" include chemical or
biological agents that may cause adverse
effects if exposure levels are high
enough. They may pose a risk to human
health and/or ecological health if they
reach receptors (USDWs, drinking water
supply wells, surface waters) at
sufficiently high concentration levels.
EPA has included USDWs as a receptor
because of the Agency's responsibility
under the Safe Drinking Water Act to
prescribe regulations for State
underground injection programs, like
Florida's, that contain minimum
requirements to prevent underground
injection from endangering USDWs.
In cases where injectate has received
secondary treatment only, bacteria,
viruses, and protozoa (e.g.,
Cryptosporidium and Giardia) are
generally not inactivated prior to deep
well injection in South Florida. In cases,
such as Pinellas County, where injectate
has been treated to reclaimed water
standards, viruses and bacteria have
likely been largely inactivated through
disinfection and protozoa have been
largely removed through filtration.
Disinfection (or chlorination) by-
products such as trihalomethanes may
also be present in some wastewater,
although no data are available to suggest
that such by-products are a serious
concern for deep well injection or any
of the other wastewater management
options studied in South Florida. EPA
would not expect such by-products to
be present in wastewaters that have not
undergone basic disinfection, as is often
the case for Class I injectate.
Nutrients are potential ecological
stressors for deep well injection,
assuming the injected wastewater
contains significant quantities of
nutrients and assuming the injected
wastewater is able to migrate
underground and discharge into the
ocean or into other surface water bodies.
Nutrients can potentially stimulate
production of algae, which can lead to
adverse side effects such as
eutrophication. Nitrogen is the primary
nutrient concern for Class I injection,
because of its mobility in ground water.
Nitrogen is also the primary nutrient of
concern if it migrates to the ocean,
because it is generally the limiting
nutrient for algae production in the
ocean. Phosphorus is of less concern for
underground injection because it tends
to adsorb quickly to sediment or soil.
C. What Exposure Pathways Are (or May
Be) of Significance for Deep Well
Injection?
An "exposure pathway" is the course
a stressor takes from a source of release
to an exposed organism. It is defined by
the different environmental media
through which a stressor migrates (e.g.,
air, surface water, ground water) as well
as the mechanism by which an organism
is actually exposed (e.g., inhalation,
drinking).
There are documented impacts to
USDWs resulting from deep well
injection in South Florida, which raise
concerns about potential human
exposures via the drinking water
pathway. Beginning in the late 1980s,
ground water monitoring wells at 18 of
the 45 municipal facilities that utilize
Class I deep well injection in South
Florida began to detect the movement of
fluid outside of the permitted injection
zones. Movement of effluent into
USDWs either has been confirmed or is
suspected at nine facilities, as
evidenced by levels of nitrates and
ammonia, as well as significant changes
in dissolved solids concentrations.
Contaminants released by deep well
injection can migrate through the
subsurface and discharge into marine
and/or surface waters, where they could
pose risk via other pathways if loadings
were sufficiently large. Such subsurface
transport is especially a concern where
contaminants can migrate relatively
rapidly and with relatively little
attenuation through preferential flow
paths (fractures, faults, and solution
cavities) common in the carbonate rocks
in South Florida. Potential concerns
associated with injectate migrating into
the ocean or other surface water bodies
could include the risk of ecological
damage as well as the risk of human
exposure to contaminants through such
recreational activities as fishing,
swimming, and boating.
D. What Is the Overall Estimate of Risk
for Deep Well Injection?
The human health risks associated
with deep well injection of treated
municipal wastewater in South Florida
are generally low. Several factors affect
risk levels at particular sites.
The degree of wastewater treatment,
and in particular the level of
disinfection and filtration of pathogenic
microorganisms (e.g., Cryptosporidium,
Giardia), is one such factor. Risks are
lower when wastewater has been treated
to remove microorganisms. For
wastewater that has received only
secondary treatment, risk would be high
in situations where the injectate
migrates through fractures, faults, and
solution cavities and lower in situations
where the injection is dominated by
porous media flow, characterized by
long travel times to current or potential
drinking water sources, and flows
through fine pore spaces capable of
retaining microorganisms.
Once Cryptosporidium, Giardia, and
other stressors are released to the
environment, the level of risk they pose
to human health depends largely on
how likely they are to enter drinking
water supplies and over what time
horizon. The record shows that such
contamination of drinking water
supplies or USDWs is a possibility as a
result of the movement of fluid found at
some injection facilities. In some cases,
the time frames for fluid to potentially
reach USDWs are short enough that
treatment of injectate (i.e., inactivation,
filtration) may be warranted.
Overall, the risk to surface water
ecosystems is low when treated
wastewater is managed by deep well
injection in South Florida. The potential
for damage may be higher where treated
wastewater is released in proximity to
surface water that already has impaired
water quality, which is the case for
many surface water bodies in South
Florida. In these cases, the nutrients that
might enter impaired waters could
exacerbate existing water quality and
ecological problems. The dynamics of
potential fluid movement from UIC
wells to surface waters is still not well
understood, however, at present there is
no evidence of contamination of surface
water by Class I injectate.
Deep well injection could also pose a
risk to marine ecology if contaminants
readily migrate and discharge to
offshore waters. However, whether this
actually happens in South Florida, and
whether it poses a real threat in the
ocean, is unknown. Given, however,
that direct discharge of effluent which
has received only secondary treatment
and basic disinfection to the ocean
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appears to pose little risk due to rapid
dilution, it is unlikely that seepage from
ground water to the ocean would pose
a significant risk.
E. What Are the Important Data Or
Knowledge Gaps for Deep Well
Injection?
In conducting the relative risk
assessment, EPA found that there is a
lack of definitive studies in South
Florida that use a physical or chemical
tracer or indicator to show whether
stressors detected in aquifers come from
treated wastewater managed by deep
well injection, and if so, by what likely
contaminant transport pathways (porous
versus conduit flow). In addition,
without more definitive tracer studies, it
is difficult to assess the potential effects
of local geochemical conditions on the
fate and transport of injected treated
wastewater.
While results from ground water
monitoring around some Class I
municipal wells in South Florida
confirm that fluids have migrated out of
the permitted injection zone, the full
areal extent of USDW contamination is
not known. This is not only because
available monitoring data are limited,
but also because the location and
connectivity of natural conduits for
fluid flow (fractures and solution
cavities in the underground formations)
are difficult to predict.
The fate and transport of pathogens in
South Florida's aquifers are not
completely understood. For example,
the rates of microbial survival,
inactivation, and transport are difficult
to predict. Also uncertain are the rates
of microbial straining or filtration by
geological materials under different
fluid flow scenarios, including porous
media and conduit flow. Even with the
most sophisticated modeling, or with
expensive monitoring, this information
is difficult to verify since the formations
are thousands of feet underground.
There is also insufficient data at present
on the presence and viability of
pathogens in injectate that has migrated
out of the injection zone. However, the
presence of coliform bacteria in injectate
that has migrated, a long accepted
indicator of the presence of sewage,
indicates the likely presence of
pathogenic microorganisms.
IV. Relevance of These Findings for the
Final Rule for Class I Municipal Wells
in South Florida
EPA requests comment on how the
findings from the relative risk
assessment, and identified data gaps,
help inform the final regulatory action
on the July 7, 2000, proposal. EPA
specifically requests comment on the
three issues discussed below.
A. Additional Wastewater Treatment
Prior to Injection
EPA believes the following findings
from the relative risk assessment are
relevant to the question of the extent to
which additional treatment may be
needed for Class I injectate that has a
potential to reach USDWs.
1. Wastewater that does not undergo
disinfection contains viruses and
pathogenic bacteria and protozoa that
have not been inactivated. Although the
fate and transport of these pathogens in
South Florida's subsurface is not well
known, monitoring and modeling data
suggest that, at some sites, fluid may
migrate at rates that are sufficient to
transport active and infective pathogens
into USDWs. For example, using first
order analytical modeling with
conservative parameters and assuming
flow is dominated by bulk flow through
preferential flow paths, travel times to
the base of the USDW of 170 days, 14
years, and 86 years have been estimated
for Pinellas, Dade, and Brevard Counties
respectively. There is significant
uncertainty as to how long the viruses,
protozoa, and bacteria will remain alive
and to what extent they may affect
existing and future sources of drinking
water, although it is expected that
significant attenuation and die-off
would occur in the deep subsurface over
long travel times. The limited data that
are currently available show one-log
(90%) inactivation rates in aquatic
media ranging from 40 to 200 days for
Cryptosporidium, 6 to 50 days for
bacteria, and 1 to 30 days for viruses.
This suggests that pathogen
contamination would likely be a
concern in areas where travel times are
potentially short (e.g., Pinellas County).
For such areas, additional treatment
(e.g., primary treatment, coagulation,
settling, filtration, and high-level
disinfection) would likely be needed to
inactivate, remove, or greatly reduce
pathogens in order to increase the level
of protection for current and future
sources of drinking water. (As noted
above, wastewater in Pinellas County is
already treated to reclaimed water
standards, which include both
disinfection and filtration.) Additional
treatment beyond secondary may also be
appropriate to address pathogenic
microorganisms in cases where injection
of large volumes of wastewater increases
the uncertainty regarding the areal
extent of fluid movement and travel
times for fluid to potentially reach
USDWs.
2. Insufficient confinement is evident
at some facilities and locations. At nine
facilities, there is either confirmed or
suspected contamination of USDWs as a
result of the movement of fluid from
designated injection zones. This is a
violation of Federal and State Class I
UIC requirements, which prohibit any
contaminants from entering USDWs. At
nine other facilities, there is evidence of
movement outside of the injection zone,
though not yet into USDWs. Monitoring
reports from some facilities suggest that
fluid movement has resulted in
fluctuations in total dissolved solids
(TDS) concentrations and less
pronounced changes in the
concentrations of other potential
stressors (e.g., fecal coliform, nitrate,
ammonia, and total Kjeldahl nitrogen).
Such fluid may have the potential to
contaminate future sources of drinking
water and place existing public and
private water supplies at risk.
3. The full areal extent of fluid
movement is not known. Nearly 500
million gallons per day (mgd) are
disposed of through deep well injection
at 42 sites in South Florida, with rates
for individual wells ranging from less
than 1 to more than 100 million gallons
per day (mgd). While the dynamics of
horizontal movement at any of these 42
sites of this quantity of water are not
well understood, there is some evidence
that water with the potential to reach
USDWs (due to inadequate
confinement) may not travel far. The
first-order analytical modeling results
presented in the relative risk assessment
show horizontal travel distances at the
surface ranging from 0.1 to 1.6 miles
assuming rapid (bulk) vertical flow, and
ranging from 1.2 to 16 miles assuming
slow (porous media) flow. Note that a
travel distance of 16 miles is modeled
to occur only under a very long time
horizon (1,188 years). Two members of
EPA's External Peer Review? Panel
expressed concern, however, regarding
the feasibility of using numerical
models to assess the pattern of flow in
and around the discharge zone (known
as the Boulder zone), and to account for
several trillion gallons of treated
municipal wastewater that has been
injected into the Boulder zone since the
inception of Florida's Class I UIC
program. These Panel members also
pointed out that the risk could be
significantly higher to USDWs than the
modeling calculations that assumed
porous media flow suggest, due to large
uncertainties that were not accounted
for in this modeling. In response to
these concerns, EPA developed a second
model assuming bulk flow through
preferential flow paths, with travel
times for injectate to reach USDWs and
drinking water wells that were an order
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23671
of magnitude shorter than the porous
media flow model. EPA believes, and
the reviewers agreed, that this second
model largely addresses the concerns
raised, but recognizes that significant
uncertainty regarding the dynamics of
underground fluid movement remain.
4. The location and connectivity of
natural conduits for flow (i.e., fractures,
faults, and solution cavities) are
unknown, although their existence is
well known by the type of rock present
(e.g., limestone) and confirmed by logs
during deep well construction. Where
such conduits are present, they may
contribute to rapid migration of injected
fluids or displaced formation water,
with little attenuation of contaminant
concentrations. Furthermore, such
conduits may result in unpredictable
patterns of movement in the subsurface.
The relative risk assessment attempts to
simulate such flows on a regional (not
site-specific) basis using a first order
analytical model with conservative
parameter assumptions. However, there
is significant uncertainty in these
results.
B. Feasibility of a Hydro-geologic
Demonstration
Option 2 proposed on July 7, 2000, (as
described above) would allow facilities
operating Class I municipal wells that
have caused or may cause fluid
movement in South Florida to continue
injection if they perform a detailed
hydrogeologic demonstration showing
that injection will not cause fluids to
migrate and cause USDWs to exceed any
national primary drinking water
regulations in 40 CFR part 141, and
other health-based standards. Where
this demonstration cannot be made,
Option 2 would require facilities to
provide additional treatment as
necessary to address contaminants of
concern and ensure that the continued
injection does not endanger USDWs. All
facilities qualifying for authorization to
inject in accordance with Option 2
would be required to have advanced
wastewater treatment and high-level
disinfection in place by the year 2015.
This requirement to phase in additional
treatment by 2015 was intended to
provide municipalities with more time
to provide additional treatment if the
municipality could conduct a successful
hydrogeologic demonstration.
EPA believes the following relative
risk assessment findings are relevant for
assessing the feasibility of conducting a
credible detailed hydrogeologic
demonstration, as proposed under
Option 2.
1. As noted in the preceding section,
the specific location, extent, and
connectivity of natural conduits for flow
are unknown and unpredictable in the
South Florida areas targeted by the
proposal. Therefore, some of the key
parameter values that would be used in
ground water modeling may be highly
uncertain, and this may lead to a broad
range of predicted results for the
location and movement of the injected
fluid. The relative risk assessment
attempted to address this issue on a
regional (not site specific) basis by using
first order analytical methods to
modeling bulk/preferential flow. This
may or may not be practicable for site-
specific numerical modeling.
2. The ground water monitoring wells
(or networks of monitoring wells) at
most deep well facilities in South
Florida are sufficient only for the
purpose of providing an early warning
of fluid movement. Typically, ground
water monitoring networks are used at
waste management facilities (e.g.,
hazardous waste landfills) to detect and
characterize the movement of relatively
small volumes of contaminants in
shallow ground water. No deep well
municipal waste disposal facilities in
South Florida have designed,
constructed, and implemented ground
water monitoring programs capable of
describing the full areal extent of fluid
movement, especially where natural
conduits for flow are present. In
addition, few facilities perform
extensive monitoring between the base
of the lowermost USDWs and the
shallower surficial aquifers. As noted
above, however, modeling results
suggest that the areal extent of
contamination that reaches the surface
rapidly through preferential flow may
be limited (up to a few miles), although
there is significant uncertainty in these
results due to the volumes of fluid being
injected and the possibility of fairly
rapid horizontal movement in the
Boulder zone below the USDW, which
was not explicitly modeled.
3. It is unclear whether it would be
practicable to provide enough
additional ground water monitoring
wells to provide the information needed
to demonstrate that fluid movement is
not occurring and USDWs are not being
contaminated at sites where natural
conduits for flow exist. Because flow
could well progress at different rates in
different directions, monitoring results
for well locations at such sites would
not necessarily be representative of
conditions at unmonitored locations.
Furthermore, there could be concern
about the installation of many
monitoring wells to examine a
particular site, because they may
penetrate rock and other materials that
are otherwise barriers to fluid
movement. If such monitoring wells are
constructed or managed improperly,
they could present man-made conduits
for fluid movement.
C. Some Deep Wells May Have Been
Misclassified as Class I, When They Are
Actually Class V
Given the extent of fluid movement
documented at some sites, as well as
information concerning the geology and
the construction of some municipal
wells in South Florida, it is possible that
some wells may have been misclassified
as Class I when they are actually Class
V. According to the Federal UIC
regulations, Class I wells "inject fluids
beneath the lowermost formation
containing, within one quarter mile of
the well bore, an underground source of
drinking water" (40 CFR 144.6(a)(2)).
Class V wells are defined as wells that
are not included in Class I, II, III, or IV.
Typically, Class V wells release non-
hazardous fluids into or above
formations containing USDWs.
Separate from the issue of how Class
I and Class V wells are defined, the
Federal Class I and Class V UIC
programs differ in their basic approach
to protecting USDWs. The basic
standard of protection in the Class I
program is to ensure that there is no
movement of any contaminant into
USDWs. This standard is achieved
through a Class I regulatory program
that focuses on the development and
enforcement of stringent permit
requirements, including, but not limited
to, criteria for well siting, construction,
and operation and maintenance. A key
component of the Class I program is
ensuring that adequate confinement
exists between the permitted injection
zone and USDWs at a given site.
Since most Class V wells release
fluids either directly into or above
USDWs, they by definition cause the
movement of fluid, which may contain
contaminants, into or above USDWs.
Therefore, the basic standard of
protection in the Class V program is to
prevent any contaminants in the fluid
from endangering USDWs. Protection
efforts in the Class V program mainly
focus on regulating and monitoring
injectate quality to ensure that the
movement of injected fluid will not
contain any contaminants that may
endanger USDWs. This standard is
achieved through inventory and
assessment requirements, additional
reporting requirements, closure
requirements, and other requirements
(possibly including permitting
requirements) believed by UIC program
staff to be necessary to protect drinking
water supplies.
The failures of confinement that have
been documented at some municipal
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well sites in South Florida, which are
most likely attributable to the presence
of natural conduits for flow in the
subsurface, suggest that the injection
zones used by these municipal wells are
not sufficiently separated from
overlying USDWs by a confining layer
to prevent fluid movement upward into
the USDW. The injectate from these
wells is, therefore, entering into a
USDW. Injection zones in South Florida
often share a "degree of lithologic
homogeneity" (as specified in the 40
CFR 144.3 definition of "formation")
with the overlying "confining layers"
and USDWs (i.e., each consists of
carbonate sequences). In some locations,
the injection zones, "confining layers,"
and USDWs may be said to exist within
one formation. It is possible that a well
injecting at such a location may not be
appropriately classified as a Class I well.
Information collected for the relative
risk assessment raises a question as to
whether certain South Florida
municipal disposal wells should have
been classified as Class V at the time
they were first permitted. In particular,
all of the lithologic units of the upper
Floridan Aquifer in Pinellas County and
the lower Floridan Aquifer in Miami-
Dade consist of limestone and dolomite
that have shown evidence of solution
cavities and fractures. These natural
conduits for fluid flow raise a question
as to whether lithologic units in these
aquifers are effective confining layers
and whether the injection zones and
overlying USDWs are in different and
distinct formations, as they were
believed to be when the wells were
originally sited, constructed, and
permitted as Class I wells.
V. Solicitation of Comment
In the July 7, 2000, proposed rule (65
FR 42234), EPA proposed regulatory
options that would allow for continued
wastewater injection by existing Class I
municipal wells that have caused or
may cause fluid movement in specific
areas of Florida. The relative risk
assessment described in this notice and
in a companion notice appearing
elsewhere in today's Federal Register
contains some new information
regarding the potential risks of deep
well injection of municipal wastewater
in South Florida. The Agency is
soliciting comment on whether and how
the findings of the relative risk
assessment should inform the Agency in
developing the final rule for wells
currently classified as Class I deep
municipal wells in South Florida.
In addition to the issues discussed
above, the Agency is soliciting comment
on the following three issues:
1. The Agency solicits comment on an
alternative option for defining the
appropriate level of wastewater
treatment required for continued
injection in deep municipal wells in
South Florida. The proposed rule
solicited comment on four levels of
advanced wastewater treatment,
nutrient removal, and high-level
disinfection that, under Option 1 and by
the year 2015 under Option 2, would be
required of facilities operating wells that
have caused or may cause fluid
movement. The alternatives proposed
under Option 1 were: (1) Treatment to
10—24 mg/1 biochemical oxygen demand
(BOD) with disinfection; (2) treatment to
10-24 mg/1 BOD with disinfection and
nutrient removal; (3) treatment to <10
mg/1 BOD with disinfection; and (4)
treatment to <10 mg/1 BOD with
disinfection and nutrient removal.
These levels were used by the 1996
Clean Water Needs Survey Manual to
delineate and cost levels of advanced
treatment. To achieve high-level
disinfection, the proposal said owners
and/or operators must allow the
wastewater to remain in contact with at
least 1.0 mg/1 of free chlorine for at least
15 minutes of contact with no fecal
coliform.
Several commenters suggested that
the proposed standards for BOD
removal are inappropriate for the
protection of ground water for the
purpose of protecting human health.
These commenters stated that BOD
levels are typically used for the
protection of ecological values in
surface water, not the protection of
human health associated with drinking
ground water. The commenters also
pointed out that the main stressor of
concern in the injectate is pathogens,
not BOD. Separately, commenters noted
that EPA's proposed definition of high-
level disinfection differs from the State
of Florida's definition of the same term
in Rule 62-600.440, F.A.C., which
commenters thought would result in
confusion. Other commenters suggested
that any new EPA wastewater treatment
requirements should be consistent with
corresponding state requirements. For
example, Florida's regulations for waste
treatment and disinfection applicable to
reclaimed water that may come into
human contact (Rule 62-610.460,
F.A.C.) and ground water disposal by
underground injection in Class V wells
(Rule 62-600.540(2) and (Rule 62-
600.440(5), F.A.C.) are similar to the
more advanced levels of treatment
envisioned under Option 1 of the
proposed rule that require filtration
before disinfection. As stated in the
Florida regulations, by removing TSS
before disinfection, filtration serves to
increase the ability of the disinfection
process to inactivate viruses and other
pathogens. Filtration also serves as the
primary barrier for removal of protozoan
pathogens (Cryptosporidium, Giardia,
and others).
Based on these comments, EPA is
now considering and soliciting
comments on prescribing wastewater
treatment requirements in language that
differs from the four alternatives
proposed on July 7, 2000 but conforms
with relevant state requirements. The
Agency is not asking for additional
comment on the four levels of advanced
wastewater treatment, nutrient removal,
and disinfection described in the
proposal. Under this alternative, the
Agency would simply adopt, in lieu of
the four standards in the proposal, the
Florida standards in Rule 62-610.460,
F.A.C. (for waste treatment and
disinfection applicable to reclaimed
water that may come into contact with
people) or the standards in Rule 62-
600.540(2) and Rule 62-600.440(5),
F.A.C. (for ground water disposal by
underground injection in Class V wells).
Specifically, EPA would require
advanced wastewater treatment that
results in treated water meeting, at a
minimum, secondary treatment and
high-level disinfection as defined in the
Florida regulations. Also, filtration
would be required for TSS control prior
to disinfection, which would specify
that the treated wastewater not contain
more than 5.0 mg/1 of TSS before the
application of the disinfectant. EPA
believes that this treatment standard
might offer some important advantages
over the alternatives proposed before. In
particular, it might better address the
risks associated with pathogens, and it
would be consistent with the standards
already adopted and implemented in
Florida for reclaimed water and
wastewater disposed of through Class V
injection wells, which are part of
domestic wastewater treatment systems.
The Agency asks commenters if this
standard for advanced treatment and
high-level disinfection should be
specified in the final rule and requests
that commenters describe the type of
treatment that would be necessary to
achieve the performance standards (i.e.,
national primary drinking water
regulations and other health-based
standards). Although the Agency
believes that the design and
construction costs of this option are
equivalent to those for the earlier
proposed treatment options that
required treated effluent concentration
of less than 10 milligrams per liter of
BOD, the Agency requests that
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23673
commenters provide any information
they have on the costs of this option.
2. The proposed rule solicited
comment on a second option, Option 2,
that would allow facilities operating
wells that have caused or may cause
fluid movement to conduct
hydrogeologic demonstrations to show
that injection will not cause fluids that
exceed any national primary drinking
water regulations in 40 CFR part 141
and other health-based standards to
enter any USDW. Option 2 would also
require well owners and/or operators
that cannot make this demonstration to
provide additional treatment as needed
to address contaminants of concern.
Further, Option 2 requires advanced
wastewater treatment and high-level
disinfection to be in place by 2015. The
Agency requests comment on whether
the findings from the relative risk
assessment, specifically those regarding
deep well injection, suggest anything
regarding the practicability and
feasibility of this approach. Should
facilities be granted the opportunity to
conduct hydrogeologic demonstrations
(and expend the resources and funds
necessary) despite the inherent
difficulties and uncertainties regarding
the extent, location, and connectivity of
possible natural conduits for flow
identified in the relative risk
assessment? If facilities should be
granted this opportunity, how should
the UIC director in his/her review of a
demonstration, address the technical
difficulties in determining the extent of
the contamination, and the location of
conduits for flow into USDWs, so that
the demonstration may be deemed
adequate? Given the uncertainty that
accompanies the effort to analytically or
numerically simulate the fate and
transport of fluid and stressors in South
Florida's deep underground
environment, EPA solicits comment on
ways that a satisfactory hydrogeological
demonstration can be conducted.
Finally, the proposed rule included a
"sunset provision" (requiring advanced
wastewater treatment and high-level
disinfection by 2015) as part of this
option even if protection of USDWs is
being demonstrated. EPA requests
comment on an alternative that would
allow the State Director to authorize
updated hydrogeologic assessments and
defer treatment requirements beyond
2015 if the assessments continued to
demonstrate adequate protection of the
USDW.
3. One option to address the fluid
movement that has occurred, while also
preventing the endangerment of
USDWs, might be to promulgate new
Class V requirements specific to deep
municipal wells in South Florida. In a
1999 stakeholders meeting, the Agency
discussed two options for reclassifying
these wells as Class V. One of these
options would reclassify the wells based
on a determination that the wells no
longer meet the regulatory definition of
a Class I well. Another option would
involve converting the wells to Class V
by physically altering the wells so that
they inject directly into or above
formations containing the lowermost
USDW. Two other options discussed at
the stakeholders meeting were (1) to
make no regulatory change (and enforce
the existing requirements) and (2) to
amend the Class I regulations to address
the fluid movement issues. EPA
ultimately proposed this last option and
published proposed revisions to the
Class I requirements. EPA stated in the
preamble to the July 7, 2000, proposal
(65 FR 42237): "The Agency is not
planning to allow reclassification unless
the well was misclassified in the first
instance. Misclassification might have
occurred if the well did not originally
meet the definition of a Class I well. The
facility could demonstrate this if new
information has become available that
proves that the well originally was
injecting into a USDW and therefore
would meet the definition of a Class V
well."
EPA is now reconsidering the
reclassification option. Reclassification
could be accomplished without any
regulatory changes to the Class I
definitions or the Class I "no fluid
movement" requirements. Following
publication of this NODA and receipt of
comments on this option, EPA, if it
chose the reclassification option, would
publish final revisions to the Class V
regulations that include the same
operating conditions that EPA would
have promulgated as revisions to the
Class I regulations. This option is
contrasted with the approach discussed
more fully in the July 7, 2000, proposal
to keep the wells as Class I and add the
necessary operating conditions to the
Class I regulations. Either approach
could be used to place the same
operating conditions on continued
injection activities and provide identical
protection to USDWs.
In addition, EPA is considering
whether there might be a need to
promulgate the operating conditions
under consideration as final regulations
under both the Class I and Class V
regulatory frameworks. This might be
necessary in order to ensure that the
new requirements apply to all
municipal waste disposal wells in South
Florida that cause or may cause fluid
movement into a USDW, regardless of
whether it is determined that a
particular well may be reclassified as
Class V or must remain in Class I. EPA
invites comment on the need for
incorporating the proposed operating
conditions into either, or both, the Class
I and Class V regulations. EPA notes
that the costs of installing a specified
level of treatment would be the same,
regardless of whether a particular well
is classified as Class I or Class V.
One potential advantage of the
reclassification option is that it could
correct any previous misclassification of
wells in South Florida.
A potential disadvantage of the
reclassification option is that it could
lead to reclassification requests
associated with other wells in other
parts of the country and could limit the
flexibility of local permit writers to
make classification determinations.
In summary, with regard to
reclassification of Class I wells, the
Agency requests comment on whether
the findings from the relative risk
assessment, specifically those regarding
deep well injection, suggest that some
South Florida wells may have been
misclassified as Class I wells? Do the
findings suggest that some wells in
South Florida may, in fact, discharge
directly to (and not below) formations
containing a USDW? Do the findings
suggest that this misclassification
should be accepted for the entire group
of South Florida municipal wells, or
only a subset? Should the regulatory
requirements under consideration be
promulgated under provisions for Class
I or Class V? If reclassification is only
appropriate for some of the covered
South Florida wells, should the
regulatory requirements under
consideration be promulgated under
provisions for both Class I and Class V.
Dated: April 17, 2003.
G. Tracy Mehan III,
Assistant Administrator for Water.
[FR Doc. 03-10268 Filed 5-2-03; 8:45 am]
BILLING CODE 6560-50-P
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 146
[FRL-7488-8]
Underground Injection Control
Program—Relative Risk Assessment
of Management Options for Treated
Wastewater in South Florida; Notice of
Availability
AGENCY: Environmental Protection
Agency.
ACTION: Notice of availability.
SUMMARY: On July 7, 2000, the
Environmental Protection Agency (EPA)
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