schedule must include when the corrective action will be completed and
any necessary milestones and temporary public health protection
measures. The PWS must notify the State when each scheduled corrective
action is completed.
    At any time during the assessment or corrective action phase,
either the PWS or the State may request a consultation with the other
entity to discuss and determine the appropriate actions to be taken.
The system may consult with the State on all relevant steps that the
system is considering to complete the corrective action, including the
method of accomplishment, an appropriate timeframe, and other relevant
information.
    E. coli detection in the distribution system indicates a public
health hazard and can result in an E. coli MCL violation. Under the
proposed rule, when an E. coli MCL violation has occurred, the system
must complete a Level 2 assessment and corrective action must be
implemented as soon as practical. The Agency encourages systems to
promptly find the source of E. coli and fix the problem before the
completed assessment form is due to the State.
    b. EPA's rationale. i. Coliform treatment technique. The advisory
committee indicated that the conditions leading to a monthly/non-acute
MCL under the current TCR should trigger an assessment under the RTCR
for several reasons. First, the advisory committee recognized that
presence of total coliform indicates the potential presence of a
pathway for contamination from external sources such as source water or
through a loss of distribution system integrity. The change to a
coliform treatment technique construct that uses total coliforms as an
indicator of distribution system integrity places the emphasis on
systems to take more preventive actions to address problems. These
actions would better protect public health than the additional
monitoring with no corrective action that is required under the current
TCR. To address the high and constant number of PWSs with violations
over the years under the current TCR, the proposed changes would be
more protective by requiring systems to correct deficiencies associated
with the non-acute MCL (see Exhibit VI.1 in section VI.C.1 of this
preamble). Second, the advisory committee indicated that the public
notice associated with non-acute violations is confusing because the
presence of total coliforms is not necessarily an indication of a
potential public health threat; however, it is an indicator of a
potential pathway for fecal contamination to enter into the
distribution system. Under the treatment technique requirement, the
presence of total coliforms (at the level equivalent to a non-acute
violation) indicates a need to assess whether a problem exists. When a
system fails to conduct the assessment, the system will then incur a
violation and be required to issue public notification. If the system
does conduct the assessment and satisfies the requirements of the
treatment technique (including corrective action when a sanitary defect
is identified), no public notification is required. Third, the
occurrence of total coliforms in the context of the coliform treatment
technique requirement continues to inform and further the original
objectives of the TCR: to evaluate the effectiveness of treatment,
determine the integrity of the distribution system, and signal the

possible presence of fecal contamination. Finally, total coliform
presence indicates the potential presence of a pathway for contaminants
from external sources such as source water or through a loss of
distribution system integrity.
    ii. Assessment. The proposed rule requires assessments to ensure
that specific action is taken to identify whether potential pathways of
contamination into the distribution system exist. The advisory
committee indicated that assessments are significant actions that
protect public health. Under the current rule, when a system has a non-
acute MCL violation and if any subsequent sampling did not detect total
coliform, the problem may persist due to the intermittent nature of
total coliform and remain unaddressed. However, the absence of total
coliform-positive samples subsequent to an initial positive finding is
not a reliable indicator that a contamination pathway no longer exists.
In contrast, the proposed revisions would ensure that systems examine
and assess the cause of the total coliform occurrence (that is
equivalent to the current non-acute MCL level) and take any corrective
action if necessary.
    Under the proposed rule, the system will also be required to
conduct an assessment if it fails to conduct repeat monitoring
following an initial total coliform-positive sample result. As
discussed in section III.A.4 of this preamble, repeat monitoring is
critical in identifying the extent, source, and characteristics of
fecal contamination in a timely manner. Since the revised rule proposes
to eliminate additional routine monitoring for systems that monitor at
least monthly and decrease the number of additional routine monitoring
and repeat monitoring samples for the smallest systems, the need to
conduct repeat monitoring is more crucial than ever in providing
immediate and useful information needed to protect public health. The
cost for collecting and analyzing a repeat sample would be considerably
less than the cost for conducting a Level 1 assessment. EPA expects
that systems will want to ensure that assessments are conducted only
when potential problems may exist rather than for failure to take
repeat samples.
    The proposed rule specifies two different levels of assessments--
Level 1 and Level 2--to recognize that a higher level of effort to
diagnose a problem applies to situations of greater potential of public
health concern such as repeated Level 1 triggers or an E. coli MCL
violation. Level 2 assessments are conducted by a party approved by the
State, which may be the PWS where it has staff or management with the
certification or qualifications as determined by the State. The Level 2
assessments may also be conducted by the State or a third party
approved by the State.
    To make more transparent what the Level 1 and Level 2 assessments
entail and to facilitate consistent implementation among States, the
proposed rule specifies minimum elements for these assessments. The
advisory committee recommended that the minimum elements identified
previously in this preamble be included in the Level 1 and Level 2
assessments to identify potential flaws in monitoring or specific
pathways of contamination. Although the proposed RTCR specifies the
same minimum elements for both the Level 1 and Level 2 assessments, the
Level 2 assessment involves a more in-depth examination of these
elements compared to a Level 1 assessment. Specific examples of how the
Level 2 assessments are more in-depth than Level 1 assessments may be
found in Appendix X of the AIP (USEPA 2008c).
    EPA recognizes that not every assessment will identify a sanitary
defect or find a reason or cause for the presence of total coliforms.
If no sanitary defect is identified, the system must document that fact
in the completed assessment form and provide supporting evidence for
this conclusion. EPA expects that only systems that adhere to proper
procedures and standards set by the State are eligible to arrive at
this determination, and only after providing sufficient supporting
evidence.
    The advisory committee recommended that the Level 1 and Level 2
assessments be conducted as soon as practical after the PWS receives
notice that the system has exceeded the treatment technique trigger.
The advisory committee also recommended that systems submit the
completed assessment forms to the State within 30 days after
determination that the PWS has exceeded the trigger. The rationale for
the 30-day interval is to allow sufficient time for problem
identification and potential remediation of the problem in conjunction
with the follow-up assessment, in most cases.
    To help States and PWSs conduct assessments, EPA intends to develop
a draft assessment and corrective action guidance manual and to make it
available for public comment prior to promulgation of the final rule
and to finalize the guidance manual after the rule is finalized.
    iii. Corrective action. The advisory committee recognized that not
every assessment will identify a sanitary defect. However, the advisory
committee recommended that the RTCR require all sanitary defects be
corrected by the system in a timely manner. The system, in consultation
with the State as needed, identifies and determines the specific
corrective action.
    Under the proposed rule, the State may allow the PWS additional
time to conduct the corrective action if needed. EPA recognizes that
some systems may not be able to fix sanitary defects before submitting
the completed assessment form within the 30-day interval due to the
extent and cost of the corrective action. In such situations, EPA
encourages the State and PWS to work together to determine the
appropriate schedule for corrective actions (which may include
additional or more detailed assessment or engineering studies) to be
completed as soon as possible. The system must comply with the agreed
upon schedule and notify the State when each scheduled corrective
action is completed.
    Either the PWS or the State may request consultation with the other
party to determine the appropriate actions to be taken. EPA is not
requiring this to be a mandatory consultation to provide ease of
implementation for States. In many cases, consultation may not be
necessary because the type of corrective action for the sanitary defect
will be clear and can be fixed right away (for example, replacement of
a missing screen).
    c. Request for comment. EPA requests comment on the: (1) Proposed
change from the non-acute MCL for total coliforms to a coliform
treatment technique requirement that uses total coliforms as an
indicator of a pathway of contamination; (2) proposed requirement for
systems to conduct an assessment following a trigger condition; (3)
proposed levels of assessment required; and (4) proposed requirement
for systems to correct all sanitary defects found during an assessment.
In addition, EPA requests comment on how to ensure that a Level 2
assessment is more comprehensive than a Level 1 assessment (e.g.,
should a Level 2 assessment include additional elements such as asset
management and capacity development?). Should EPA provide more detail,
either in guidance or rule language, on the elements and differences
between a Level 1 and Level 2 assessments? If in rule language, how
should the rule language distinguish the two levels of assessments?
Please provide examples. Additionally, should EPA provide additional
guidance on how systems might address the situation where a Level 1 or
Level 2 assessment

fails to identify any sanitary defects (i.e., the trigger event remains
unexplained). If so, what should such guidance say?
6. Violations
    a. Provisions. EPA is proposing to modify the definition of the
existing MCL violation, establish a treatment technique violation, and
revise the monitoring and reporting violations. EPA is proposing that
public notice be required for each type of violation (see section
III.A.7 of this preamble for detail information on public
notification).
    i. E. coli MCL violation. A violation of the E. coli MCL occurs
when:
     A routine sample is total coliform-positive and one of its
associated repeat samples is E. coli-positive; or
     A routine sample is E. coli-positive and one of its
associated repeat samples is total coliform-positive; or
     A system fails to take all required repeat samples
following a routine sample that is positive for E. coli; or
     A system fails to test for E. coli when any repeat sample
tests positive for total coliforms.
    ii. Coliform treatment technique violation. A coliform treatment
technique violation occurs when:
     A system fails to conduct a required assessment within 30
days of notification of the system exceeding the trigger (see section
III.A.5 of this preamble for conditions under which monitoring results
trigger a required assessment); or
     A system fails to correct any sanitary defect found
through either a Level 1 or 2 assessment within 30 days (see also
section III.A.6 of this preamble) or in accordance with State-derived
schedule.
    There would be no treatment technique violation associated solely
with a system exceeding one or more action triggers (Level 1 or Level 2
triggers).
    iii. Monitoring violation. Under the current TCR, a monitoring
violation occurs when a system fails to comply with the total coliform
monitoring requirements, including the sanitary survey requirement.
Under the proposed RTCR, a monitoring violation occurs when a system
fails to take every required routine or additional routine sample in a
compliance period, or when it fails to test for E. coli following a
routine sample that is total coliform-positive.
    In addition, if a system on quarterly monitoring has a monitoring
violation in two or more quarters, or if a system on annual monitoring
misses its annual monitoring, it must begin monthly monitoring until it
meets criteria for less frequent monitoring. See section III.A.3 of
this preamble for a detailed discussion on monitoring frequency.
    iv. Reporting violation. A reporting violation occurs when a system
that properly conducts monitoring or an assessment fails to submit a
monitoring report or a correctly completed assessment form by the
required deadline. The PWS is responsible for reporting this
information to the State regardless of any arrangement with a
laboratory. A reporting violation also occurs when a system fails to
notify the State following an E. coli-positive sample.
    b. EPA's rationale. To define violations, the advisory committee
built upon the principles underlying the current TCR violations and
current TCR public notification and suggested changes to improve public
health protection where they saw a specific need. This proposal
specifies responses to different degrees of potential public health
concern. As described in the next section on providing information and
notification to the public, Tier 1, Tier 2, and Tier 3 public notices
are required following violations corresponding to the severity of each
violation type.
    i. E. coli MCL violation. An E. coli MCL violation (which includes
failure to take all required repeat samples following an E. coli-
positive sample) creates concern of an immediate potential public
health threat. For this reason, an E. coli MCL violation is considered
an acute violation requiring immediate response by the system.
Including an E. coli MCL violation condition for systems failing to
collect all repeat samples following an initial E. coli-positive sample
enhances public health protection by preventing a system from incurring
only a monitoring violation when there is an indication of fecal
contamination. As discussed previously in section II.D of this
preamble, the presence of E. coli indicates a pathway of fecal
contamination and should be taken seriously. Systems need to follow up
with repeat samples to characterize the extent and source of such
contamination. Failure to take the required repeat samples following an
initial E. coli-positive sample is not protective of public health and
is a serious violation.
    ii. Coliform treatment technique violation. A coliform treatment
technique violation occurs when a potential pathway of contamination in
the distribution system is unexplored and/or uncorrected. Performing
the Level 1 and 2 assessments and taking corrective action are
essential aspects of compliance with the treatment technique. A system
which neglects to perform the prescribed assessment or corrective
action is in violation of the proposed RTCR's treatment technique
requirements.
    iii. Monitoring violation and reporting violation. Monitoring and
reporting violations occur when a system fails to comply with the
routine monitoring requirements or when a system fails to submit
monitoring reports or completed assessment forms. EPA believes that
monitoring violations and reporting violations need to be addressed so
that a system is held accountable to take actions to reduce public
health risk, including regular monitoring of water quality.
    c. Request for comment. EPA requests comment on the proposed
violation determinations.
7. Providing Notification and Information to the Public
    a. Provisions. To correspond to the changes in the proposed revised
rule, EPA is proposing some modifications to the public notice (PN)
requirements contained in 40 CFR part 141 subpart Q. Tier 1 PN is
required for an E. coli MCL violation. Tier 2 PN is required for a
treatment technique violation for failure to conduct assessments or
corrective actions. Tier 3 PN is required for a monitoring violation or
a reporting violation.
    In the current TCR, if a system has an acute MCL violation which is
based on the presence of fecal coliforms or E. coli, or which is based
on the system's failure to test for fecal coliforms or E. coli
following a total coliform-positive repeat sample, the system is
required to publish Tier 1 PN. Under the proposed RTCR, a system is
required to publish Tier 1 PN when it has an E. coli MCL violation (see
section III.A.6 of this preamble for what constitutes an E. coli MCL
violation). In addition, the system will continue to be required to
notify the State after learning of an E. coli-positive sample, as
currently is required under the TCR. As mentioned earlier in section
III.A.2 of this preamble, EPA is proposing to eliminate the MCL for
fecal coliforms. Under the proposed rule, the standard health effects
language, which is required to be included in all public notification
actions, is modified to delete the reference to the fecal coliform MCL
and fecal coliforms. The language for a non-acute violation under the
current TCR is modified to apply to a violation of the assessments and
corrective action requirements of the coliform treatment technique.
    In the current TCR, a system is required to publish a Tier 2 PN
when the system has a non-acute MCL violation, which is based on total

coliform presence. Under the proposed rule, a system is required to
publish a Tier 2 PN if the system violates the coliform treatment
technique requirements. Also, EPA is proposing to modify the standard
health effects language for coliform to emphasize the assessment and
corrective action requirements of the proposed rule.
    In the current TCR, a system is required to publish a Tier 3 PN
when the system has a monitoring or reporting violation. In the
proposed rule, the Tier 3 PN requirements are changed to incorporate
the recommendation in the AIP that monitoring violations be considered
distinct from reporting violations under the proposed RTCR. Both types
of violations require Tier 3 PN.
    Consumer confidence report (CCR) requirements are also modified.
Health effects language for the CCR, which is identical to the health
effects language required for PN, is updated in the same way as
described for PN. In addition, the proposed RTCR removes the CCR
requirements that require the inclusion of total numbers of positive
samples, or highest monthly percentage of positive samples for total
coliforms as well as total number of positive samples for fecal
coliforms. These provisions are replaced by requirements to include the
number of Level 1 and Level 2 assessments required and completed, the
corrective actions required and completed, and the total number of
positive samples for E. coli. Unchanged and consistent with existing
provisions under the current TCR, a CWS may provide Tier 3 PN using the
annual CCR.
    b. EPA's rationale. The proposed public notification requirements
are consistent with the AIP language as well as with the tier system
described in 40 CFR part 141 subpart Q. These changes are appropriate
because some of the types of violations in the proposed RTCR are
different from the current TCR. The standard health effects language
for the public notification is also revised as appropriate given the
changes to what constitutes a violation under the proposed RTCR.
    The proposed Tier 1 PN requirement for an E. coli MCL violation is
consistent with the current TCR. Tier 1 PN is required for NPDWR
violations and situations with significant potential to have serious
adverse effects on human health as a result of short term exposure. The
existing Tier 1 PN requires public notice as soon as possible but no
later than 24 hours after the system learns of the violation. Exposure
to E. coli in drinking water can possibly result in serious, acute
health effects, such as diarrhea, cramps, nausea, headaches, or other
symptoms and possible greater health risks for infants, young children,
some of the elderly, and people with severely compromised immune
systems.
    Tier 2 PN is required for all NPDWR violations and situations with
potential to have serious adverse effects on human health not requiring
Tier 1 PN. The system must provide public notice as soon as practical,
but no later than 30 days after the system learns of the violation. A
treatment technique violation under the proposed RTCR meets these
criteria because it is an indication that the public water system
failed to conduct an assessment or complete corrective action following
identification of sanitary defects. Identification of a sanitary defect
indicates that a problem may exist in the distribution system that has
potential to cause public health concern.
    Tier 3 PN is required for all other NPDWR violations and situations
not included in Tier 1 or Tier 2. The existing Tier 3 PN requires a
system to provide public notice no later than one year after the system
learns of the violation or situation or begins operating under a
variance or exemption. Monitoring violations and reporting violations
meet these criteria because, while they do represent a violation of the
proposed RTCR, the risk to public health is not as clearly linked as
those that are Tier 1 or 2. Therefore, EPA believes that a public
notice given at least annually fulfills the public's right-to-know
about these violations.
    Consumer confidence report requirements are updated to reflect the
advisory committee's recommendations that total coliforms be used as an
indicator to start an evaluation process that, where necessary, will
require the PWS to correct sanitary defects. EPA believes it is most
appropriate to inform the public about actions taken, in the form of
assessments and corrective actions, since failure to conduct these
activities lead to treatment technique violations under the proposed
RTCR. Because the proposed RTCR no longer includes the total coliform
MCL but now includes a trigger, EPA believes that systems no longer
need to report the number of total coliform-positive samples via the
CCR, since that could cause confusion or inappropriate changes in
behavior among consumers. In addition, the CCR requirements will also
reflect the removal of fecal coliform provisions under the proposed
RTCR.
    c. Request for comment. EPA requests comment on whether the PN and
CCR language revisions are consistent with the provisions of the
proposed RTCR that reflect the use of total coliforms as an indicator
within a coliform treatment technique. Since EPA is not aware of health
effects resulting solely from exposure to total coliforms, the proposed
RTCR eliminates the public notification requirement for detection of
total coliforms, but provides for public notification upon detection of
E. coli, and for violation of the coliform treatment technique. The
Agency does request comment, however, on the loss of information to
consumers resulting from elimination of public notification
requirements following positive sample results for total coliforms. EPA
also requests comment on whether the proposed RTCR should require
special notice to the public of sanitary defects, in addition to the PN
requirements, similar to the GWR special notice requirements. This
would be consistent with current requirements for other regulations
that limit pathogens in ground water systems. Under 40 CFR
141.403(a)(7)(i), a CWS must inform the public of the significant
deficiency and/or fecal indicator-positive sample. The CWS must
continue to inform the public annually until the significant deficiency
is corrected or the fecal contamination in the ground water source has
been determined by the State to be corrected. Under 40 CFR
141.403(a)(7)(ii), an NCWS that receives notice from the State of a
significant deficiency must inform the public of any significant
deficiency that has not been corrected within 12 months of being
notified by the State, or earlier if directed by the State. The NCWS
must continue to inform the public annually until the significant
deficiency is corrected.
8. Reporting and Recordkeeping Requirements for Systems
    a. Provisions. i. Reporting. In addition to the existing general
reporting requirements provided in 40 CFR 141.31, the proposed RTCR
requires a PWS to:
     Notify the State no later than the end of the next
business day after it learns of an E. coli-positive sample.
     Report to the State an E. coli MCL violation no later than
the end of the next business day after learning of the violation. The
PWS is also required to notify the public according to the provisions
laid out in 40 CFR part 141 subpart Q.
     Report to the State a treatment technique violation no
later than the end of the next business day after it learns of the
violation. The PWS must also notify the public in accordance with 40
CFR part 141 subpart Q.

     Report to the State monitoring violations within ten days
after the system discovers the violation, and notify the public in
accordance with 40 CFR part 141 subpart Q.
     Notify the State when each scheduled corrective action is
completed for corrections not completed by the time of the submission
of the assessment form.
    In addition, systems triggered into conducting an assessment are
required to submit the completed assessment form within 30 days after
determination that the coliform treatment technique trigger has been
exceeded (see section III.A.3 of this preamble for additional
discussion).
    ii. Recordkeeping. EPA is proposing to maintain the current TCR
requirements regarding retention of sample results and records of
decisions related to monitoring schedules found in 40 CFR 141.33,
including provisions that address the new requirements of the proposed
RTCR pertaining to reduced and increased monitoring, treatment
technique, etc. In addition, systems are required to maintain on file
for State review the assessment form or other available summary
documentation of the sanitary defects and corrective actions taken.
Systems are required to maintain these documents for a period not less
than five years after completion of the assessment or corrective
action.
    b. EPA's rationale. In the case of an E. coli-positive sample, the
proposed RTCR maintains the current TCR requirement that systems must
notify the State by the end of the day when they are notified of the E.
coli-positive result or by the end of the next business day if the
State office is already closed. The advisory committee believed that
this requirement is important to maintain because of the potential for
immediate public health risk associated with E. coli presence and the
desire for States to consider quickly whether additional actions might
be appropriate. The same rationale applies to E. coli MCL violations.
    Since there are new requirements for conducting assessments and
corrective actions, and new conditions for obtaining increased or
reduced monitoring provisions, the proposed rule includes reporting and
recordkeeping requirements to facilitate tracking of Level 1 and Level
2 triggers and compliance with treatment technique requirements.
Systems are required to maintain these files no less than five years.
Since systems have to maintain these files no shorter than the maximum
period allowed between sanitary surveys (i.e., five years; see 40 CFR
142.16(b)(3) and 40 CFR 142.16(o)(2)), States have the opportunity to
look at and review these files during sanitary surveys and/or annual
visits. The five year period is also consistent with the recordkeeping
requirements for microbiological analyses under 40 CFR 141.33(a).
    The timeframe by which reporting and recordkeeping are required
under the proposed rule is consistent with EPA's practice regarding
reporting and recordkeeping requirements in other regulations under
SDWA.
    c. Request for comment. EPA requests comment on whether the
timeframe required for reporting and recordkeeping requirements are
appropriate.
9. Analytical Methods
    a. AIP-related method issues. i. Evaluation of currently-approved
methods. The AIP contains several recommendations by the advisory
committee regarding the analytical methods approved under the proposed
RTCR. The advisory committee noted that the methods currently approved
under the current TCR have varying sensitivities and specificities, and
recommended that `` * * * the Agency evaluate all currently approved
coliform analytical methods to determine whether these methods continue
to be appropriate for use in drinking water compliance monitoring''
(USEPA 2008c, AIP p. 7).
    In the twenty years since the current TCR was promulgated, many
methods have been developed and approved for use. Most of the approved
methods that are used to support the current TCR were evaluated under
EPA's Alternate Test Procedure (ATP) process. Under this process, a
proposed method is evaluated in comparison to a reference method. A
favorable comparison serves as the basis for subsequent approval of the
method for use in regulatory compliance monitoring.
    The ATP evaluations are designed based on the ATP Microbiology
Protocol (USEPA 2004), an EPA guidance document that outlines how the
evaluation study should be conducted. In the years the ATP program has
been in place, the ATP guidance document has been revised several
times. As a result of different protocols being used over time, the
current set of approved methods have not all been evaluated under
identical conditions.
    In addition to the concerns expressed by the advisory committee
that the approved methods may not be equivalent to each other, EPA
notes that there have been additional concerns with some of the methods
currently approved. This includes allegations that some of the approved
methods may have been modified since approval without EPA's knowledge.
EPA is also aware of reports of varying performance of some enzyme-
based methods (Oldstadt et al. 2007; Fricker et al. 2003). Lastly, EPA
is aware of at least one circumstance where the manufacturer of an
approved method placed a ``product hold'' and recall on the medium
after the product was reported to be experiencing reduced recovery of
E. coli.
    For these reasons, EPA believes that additional information may be
needed regarding the performance of the currently approved methods in
order to justify their continued approval. Among the options, EPA is
considering a complete, side-by-side method evaluation study, whereby
all the methods are compared to each other under identical conditions,
according to the same protocol.
    EPA is considering an approach under which vendors of all currently
approved methods would have the option of voluntarily participating in
an independent, third-party laboratory evaluation through EPA's
Environmental Technology Verification (ETV) Program. The goal of the
ETV Program is to provide independent, objective, and credible
performance data for commercial-ready environmental technologies. More
information on this program is available on EPA's Web site at
www.epa.gov/etv/index.
    Under the ETV approach, EPA anticipates that participating vendors
would generally fund the majority of the cost of their method
evaluation. Based on the results of the ETV study, as documented in the
verification report, EPA would judge the appropriateness of each
analytical method and would determine which should continue to be
approved for future monitoring. EPA would then make any changes to the
analytical methods approved under the RTCR through later rulemaking.
    If a vendor chooses not to participate in the ETV study, EPA would
allow the vendor to propose, for EPA's consideration, an equivalent
alternative approach for method evaluation. EPA will determine whether
the proposed approach will provide an independent, effective, and
credible evaluation. EPA emphasizes that any alternative approach would
need to be equivalent in scope and rigor to the ETV program. As with
the ETV study, EPA would use the results from an alternative study to
judge the appropriateness of each analytical method and would determine
which methods warrant approval for future monitoring under this
regulation.

    As described at EPA's April 2009 stakeholder meeting, the time
required to plan and conduct a proper method evaluation, and to assess
the results, is such that EPA does not expect to be able to complete
this effort and to take action on the method evaluation in time for the
results to be included in the final RTCR. Instead, and to the extent
necessary, EPA would address the disapproval of any of the current
methods, or restrictions on any methods, in independent regulatory
actions.
    ii. Review of ATP protocol. The AIP further recommends that EPA
``engage stakeholders in a technical dialogue in its review of the
Alternative Test Procedure (ATP) microbial protocol for TC/E. coli
methods for drinking water to determine if the criteria for acceptance
of methods are consistent with the intent and objectives of the TCR * *
*'' (USEPA 2008c, AIP p. 7). In response, EPA notes that the study plan
developed for the re-evaluation of current methods (under an ETV or
alternative approach) could serve as a starting point for discussions
with stakeholders regarding the basis for evaluating new methods. The
study plan could be used as a model for a revised ATP protocol; lessons
learned from the re-evaluation could also inform EPA's future
assessment of new methods.
    iii. Approval of ``24-hour'' methods. The AIP also recommends that
EPA ``consider approving methods that allow the timely (e.g. on the
order of 24 hours) analytical results for E. coli and TC and that
provide relatively concurrent analyses, without significantly
sacrificing accuracy, precision and specificity'' (USEPA 2008c, AIP p.
7). EPA notes that many of the approved methods that may be used in
compliance with the proposed rule can be completed in approximately 24
hours. However, the methods that detect lactose fermentation include a
confirmation step that involves transfer of a presumptively positive
culture into a more inhibitory confirmation medium which serves to
ensure the initial positive was correct. As a result of this
confirmatory step, lactose fermentation methods can take up to 96 hours
to obtain a result. The enzyme based methods do not require this
confirmation step, and their results can be obtained in a 24 to 48 hour
time period.
    EPA is aware of some concerns that methods with a 24 hour
incubation time may not be able to detect as many coliform bacteria as
methods with a 48 hour incubation period. Since many of the coliform
bacteria found in a distribution system are injured or stressed due to
disinfection practices, and since injured/stressed organisms may take
longer to detect than 24 hours, this concern is of interest to EPA. As
part of, or in addition to, the method evaluation previously described,
EPA may therefore further investigate the impact of incubation time on
the recovery of stressed/injured organisms in drinking water using
approved media. At this time, EPA believes that it is premature to
conclude that either enzyme-based or lactose-based methods are
inherently preferable.
    As discussed during the advisory committee meetings, the analysis
time of the analytical methods is just one aspect in the overall amount
of time it takes before a PWS obtains sample results from the
laboratory and subsequently collects repeat samples. Factors that can
impact how quickly the PWS receives notification of a positive result
include whether the PWS uses an in-house laboratory or must ship the
sample to a distant contract laboratory, and whether the sample results
are reported via an electronic means or via traditional mail. In
addition, the turnaround time for repeat sampling can be affected by
such factors as the laboratory daily hours of operation. The current
TCR specifies that repeat samples be collected within 24 hours, but
States currently have the flexibility to extend this timeline. The
current TCR does not contain provisions for how quickly the laboratory
must notify the PWS when a positive result is obtained. This proposal
does not change these provisions.
    iv. Elimination of fecal coliforms under the proposed RTCR. The AIP
also contains a recommendation that EPA remove all provisions related
to fecal coliforms under the proposed RTCR. Consistent with this
recommendation, and for the following reasons, EPA is proposing to
eliminate all fecal coliform provisions in the RTCR.
    First, the fecal coliform group can contain bacteria not associated
with fecal contamination. E. coli is the most prominent member of the
fecal coliform group. However, other coliform bacteria, such as
thermotolerant strains of Klebsiella spp., have been shown to occur in
the fecal coliform group (Warren et al. 1978). These non-E. coli
bacteria are often found in environmental sources (for example, soil,
vegetation, water) and, therefore, are not exclusively associated with
feces. Due to the presence of these non-fecal bacteria, the fecal
coliform group may not always provide the public water system with
meaningful data regarding the vulnerability of their distribution
system to fecal contamination.
    Secondly, when the current TCR was developed, there were few E.
coli methods available. Many public water systems were familiar with
and preferred to use the fecal coliform methods. However, since the
current TCR was promulgated, many E. coli methods have been developed
and approved for use. EPA believes that most systems nationwide
currently test for E. coli, while few test for fecal coliform bacteria.
Since the methods used to test for E. coli have approximately the same
cost as those used to test for fecal coliform bacteria, this proposed
change is not expected to create an additional burden on PWSs.
    EPA is proposing to eliminate all analytical method provisions for
fecal coliforms that are included in the current TCR. EPA proposes
instead to allow testing only for E. coli following a total coliform-
positive sample. This change will provide the water system with more
meaningful information regarding potential fecal contamination of the
distribution system.
    The current TCR specifies a number of analytical methods that can
be used for compliance sample analysis (in 40 CFR 141.21(f)). Since
fecal coliform bacteria are not regulated contaminants under this
proposed rule, the analytical methods for fecal coliforms are no longer
applicable and are removed from the list of analytical methods. All
other methods used for compliance with the current TCR are maintained
for compliance sample analysis under the proposed RTCR.
    v. Request for comment on AIP-related method issues. EPA is
requesting comment on the following RTCR analytical method issues
related to recommendations from the TCRDSAC in its AIP:
     The use of an ETV approach for a reevaluation of
analytical methods.
     Whether the RTCR should include provisions to ensure a
more expedited results notification process. The RTCR could, for
example, include language requiring that PWSs arrange to be notified of
a positive result by their laboratory within 24 hours.
     Whether the RTCR should require repeat samples be taken
within 24 hours of a total coliform-positive with no (or limited)
exceptions.
    b. Other method issues. In addition to addressing the
recommendations of the advisory committee, EPA is proposing some minor
technical changes related to analytical methods. Many of these changes
document practices that are already followed by PWSs and laboratories,
and are consistent with the

Manual for the Certification of Laboratories Analyzing Drinking Water
(referred to as the ``Laboratory Certification Manual'') (USEPA 2005),
an EPA document that outlines method requirements and good laboratory
practices for certified laboratories conducting drinking water
compliance sample analyses.
    Some of these changes were brought to the attention of EPA by EPA
Regions and States involved in the implementation of the drinking water
certification program. Other minor changes have been proposed to make
the analytical methods section of this regulation easier to understand
and implement. Each proposed change is described as follows with a
discussion of the rationale for the change.
    i. Holding time. The proposed RTCR continues to provide a 30-hour
holding time limit for the samples collected in compliance with this
regulation (40 CFR 141.21(f)(3)). However, EPA is proposing to change
the definition for holding time from ``the time from sample collection
to initiation of analysis may not exceed 30 hours'' to ``the time from
sample collection to initiation of test medium incubation may not
exceed 30 hours.''
    ii. Dechlorinating agent for sample preservation of chlorinated
water supplies. The proposed RTCR establishes the following provision:
``If chlorinated water is to be analyzed, sufficient sodium thiosulfate
(Na2S2O3) must be added to the sample
bottle before sterilization to neutralize any residual chlorine in the
water sample.'' Dechlorination procedures are addressed in section
9060A.2 of Standard Methods for the Examination of Water and Wastewater
(20th and 21st editions) (Clesceri et al. 1998; Eaton et al. 2005).
    iii. Filtration funnels. EPA is proposing to add the following
footnote to the analytical methods table (Sec.  141.852) under the
revised rule:

    All filtration series must begin with membrane filtration
equipment that has been sterilized by autoclaving. Exposure of
membrane filtration equipment to UV light is not adequate to ensure
sterilization. Subsequent to the initial autoclaving, exposure of
the filtration equipment to UV light may be used to sanitize the
funnels between filtrations within a filtration series.

    iv. Analytical methods table changes. EPA is proposing the
following changes to the analytical methods table:
     The table is organized by methodology (e.g., lactose-
fermentation methods vs. enzyme-substrate methods).
     E. coli methods are included in the table.
     18th and 19th editions of Standard Methods for the
Examination of Water and Wastewater are no longer approved and have
been removed.
     The references to Standard Methods 9221A and 9222A are
removed.
     The reference to Standard Methods 9221B is changed to
9221B.1, B.2.
     The reference to Standard Methods 9221D is changed to
9221D.1, D.2.
     The table proposes to allow Standard Methods 9221D in the
multiple tube format as described in Standard Methods 9221B.
     The citation for MI agar is changed to EPA Method 1604 for
clarity and consistency.
     The table clarifies that Standard Methods 9221 F.1 and
9222 G.1a (1), (2) may be used for E. coli analysis.
     The table clarifies the correct formulation for EC-MUG
broth, when used in conjunction with Standard Methods 9222G.1a(2),
through the addition of the following footnote:

    The following changes must be made to the EC broth with MUG (EC-
MUG) formulation: Potassium dihydrogen phosphate,
KH2PO4 must be 1.5g and 4-methylumbelliferyl-
Beta-D-glucuronide must be 0.05 g.

     The table reflects the approval of a modified Colitag
method for the simultaneous detection of E. coli and other total
coliforms.
    v. EPA's rationale for proposed changes related to other method
issues. (a). Holding time.
    The current rule states ``The time from sample collection to
initiation of analysis may not exceed 30 hours'' (40 CFR 141.21
(f)(3)). Since promulgation of the current TCR, some States and EPA
Regions have commented that ``initiation of analysis'' may be
interpreted several different ways, which can lead to the sample being
held longer than the 30 hours intended by the rule. The proposed
language more clearly defines the amount of time that the sample may be
held and is consistent with section 6.4.1 of the Manual for the
Certification of Laboratories Analyzing Drinking Water which states:
``For the analysis of total coliform in drinking water, the time
between sample collection and the placement of sample in the incubator
must not exceed 30 hours.''
    EPA believes that changing the definition of holding time from
``the time from sample collection to initiation of analysis'' to ``the
time from sample collection to initiation of test medium incubation''
may slightly decrease the amount of time a PWS has to get the sample to
a laboratory. EPA does not believe that this change will significantly
reduce the amount of time a water system has to get a sample to the
laboratory, as most of the methods approved under this rule require 30
minutes or less to process and prepare the sample for the incubation
step. Thus, the initial analytical steps should not constitute a large
portion of the holding time as a whole. EPA recommends that PWSs that
have difficulty meeting the holding time notify the laboratory that the
samples are in transit and need to be given priority. The laboratory
could begin analysis immediately upon sample arrival so that the
samples could be placed in the incubator in time to meet the 30 hour
holding time. EPA notes that a laboratory may have to make specific
accommodations in their processes in order to properly analyze a sample
received close to the end of the holding time. EPA believes that this
is feasible with proper planning.
    (b). Dechlorinating agent for sample preservation of chlorinated
water supplies. Under this proposal, EPA would require that chlorinated
water samples be collected in bottles that contain the dechlorinating
agent sodium thiosulfate. This is consistent with section 3.15.4 of the
Laboratory Certification Manual, which states ``If chlorinated water is
to be analyzed, sufficient sodium thiosulfate
(Na2S2O3) must be added to the sample
bottle before sterilization to neutralize any residual chlorine in the
water sample.'' Neutralization ceases the bactericidal action of the
chlorine during sample transit, thus allowing a more accurate
assessment of what the true microbial content of the water sample was
at the time of sample collection. Implementation of this new
requirement should be straightforward since PWSs need only ask the
laboratory for pre-treated sample containers. EPA does not believe this
provision will cause an increase in cost to PWSs, as the cost of the
bottles with the sodium thiosulfate is essentially the same as the cost
of the bottles without the sodium thiosulfate.
    (c). Filtration funnels. Under this proposal, EPA is requiring that
membrane filtration equipment be autoclaved before beginning a
filtration series. This requirement is consistent with section 4.1.3 of
the Laboratory Certification Manual, which states: ``Membrane filter
equipment must be autoclaved before the beginning of a filtration
series.''
    Under the current TCR, not all of the approved membrane filtration
methods require that a filtration series begin with membrane filtration
units that have been sterilized by autoclave. Some of the approved
methods allow the laboratory to use ultraviolet (UV)

radiation exposure in lieu of autoclaving to sterilize filtration units
between filtration series. EPA does not believe that ultraviolet
radiation is sufficient to properly sterilize the membrane filtration
equipment. Additionally, EPA believes that when ultraviolet radiation
is used, not all areas of the membrane filtration equipment are
exposed, and therefore microorganisms may persist and contaminate other
water samples and the laboratory. For these reasons, EPA is proposing
to include a footnote to the analytical methods table in order to
ensure proper sterilization.
    EPA does, however, believe that ultraviolet light can be used to
sanitize the filtration equipment between filtrations within a
filtration series, as stated in section 4.1.4 of the Laboratory
Certification Manual: ``Ultraviolet light (254 nm) may be used to
sanitize equipment (after initial autoclaving for sterilization), if
all supplies are pre-sterilized. Ultraviolet light may be used to
reduce bacterial carry-over between samples during a filtration
series.''
    (d). Analytical methods table. In this proposal, EPA is identifying
a number of changes to the analytical methods table for clarity and
accuracy.
    In the current TCR, the methods are listed by date approved and the
E. coli methods are listed in a text format. In this proposal, the
analytical methods table is organized by methodology (e.g., lactose-
fermentation methods vs. enzyme-substrate methods), and the E. coli
methods are included in the table.
    Standard Methods for the Examination of Water and Wastewater is a
reference document designed to represent ``the best current practice of
American water analysts.'' Periodically, new editions are published in
order to incorporate improvements in the methods contained within this
manual. Thus, new editions of this publication contain more current and
improved versions of the methods. Under the current TCR, four editions
of this publication are approved, resulting in different, oftentimes
outdated, versions of the same method being approved. Having multiple
editions of this manual approved under this regulation also creates a
burden for the laboratory certification officers who must understand
the differences between the versions of the method for which the
laboratory may be seeking certification. For these reasons, EPA is
proposing to remove the 18th and 19th editions of Standard Methods for
the Examination of Water and Wastewater for use in compliance sample
analysis under the RTCR. EPA expects that the burden associated with
this change will be minimal as most laboratories have already procured
the newer editions or have arranged for access to the online
publication.
    In this proposed regulation, the reference to Standard Methods
9221A and 9222A are removed. These sections of the methods contain only
introductory information, not any actual methodology. They do not
represent methods approved for use under this regulation.
    The references to Standard Methods 9221B and 9221D are modified in
this proposed regulation. In the current TCR, the methods are
referenced as 9221B and 9221D with footnote 5 denoting that the
``completed phase'' called for in the methods is not required. By more
specifically citing Standard Methods 9221 B.1, B.2, and 9221 D.1, D.2
(which contain the applicable, required steps of these methods) EPA is
able to eliminate the original footnote and improve clarity.
    EPA is proposing to allow Standard Methods 9221D (Presence-Absence
broth) to be used in a multiple tube format. This method has
traditionally been used in a single bottle, allowing only the
qualitative detection of total coliforms. However, there are published
reports showing this method can be used in a multiple tube format for
the quantitative detection of total coliforms (Rice et al. 1987; Rice
et al. 1993). This medium would be used in the same manner that Lauryl
Tryptose Broth (LTB) is described as being used in Standard Methods
9221B. Allowing the use of this method in a multiple tube format would
allow PWSs that use this method to quantitate any total coliforms that
may occur in the water sample.
    EPA is proposing to change the citation for MI Agar. Under the
current TCR, this method is cited as Standard Methods 9222, with a
footnote citing the Applied and Environmental Microbiology article
where the method was initially described. In this proposal, the method
is now cited as EPA Method 1604, consistent with section <IP_ADDRESS>.3 of
the Laboratory Certification Manual. EPA Method 1604 is identical to
the citation in the TCR and does not require the use of the original
footnote. This change is also consistent with the citation of this
method as listed in the Ground Water Rule (see 40 CFR 141.402).
    The current TCR describes the use of ``EC medium supplemented with
50 [mu]g/mL of 4-methylumbelliferyl-Beta-D-glucuronide (MUG)'' (see 40
CFR 141.21(f)(6)(i)). This proposal clarifies that this medium,
included in both Standard Methods 9221F and Standard Methods
9222G.1a(2), is approved for use under this regulation. This is
consistent with the Laboratory Certification Manual, particularly
section 5.1.8, which describes both of these methods as approved for
use in the detection of E. coli under this regulation.
    Lastly, EPA is clarifying the formulation for EC broth with MUG
(EC-MUG) given in Standard Methods 9222G.1a(2) to correct an error in
the publication. The Standard Methods 9222G.1a(2) formulation calls for
0.1 g of 4-methylumbelliferyl-Beta-D-glucuronide, and 1.4g
KH2PO4. This formulation differs from that given
in Standard Methods 9221F.1, which calls for 0.05 g and 1.5 g,
respectively. EPA believes that the correct formulation is given in
Standard Methods 9221F and has confirmed this with Standard Methods
committee members (Rice 2009). Accordingly, EPA has added a footnote to
the 9222G.1a(2) stating the proper formulation.
    EPA anticipates that these changes to the analytical methods table
will not cause any additional burden to the PWSs.
    vi. Request for comment regarding holding temperature. The current
TCR states the following regarding sample shipment: ``Systems are
encouraged but not required to hold samples below 10 deg. C during
transit.'' Other national primary drinking water regulations requiring
microbial sampling require that the samples be shipped in cold
conditions, and require the sample be maintained at a temperature of 10
degrees Celsius (C) or less. Maintaining the sample temperature below
10 degrees C serves to preserve the bacterial population by minimizing
both bacterial cell death and cell multiplication, thus allowing for a
more accurate representation of the microbial population in the sample
at the time of sample collection. Also, Standard Methods for
Examination of Water and Wastewater, 21st edition (Eaton et al. 2005)
recommends that samples be shipped at less than 8 degrees C but not
frozen.
    In the years since the promulgation of the current TCR, EPA has
heard concern that at times, samples collected under the TCR may reach
high temperatures during transit to the laboratory due to the lack of a
requirement to ship samples on ice. High temperatures that may be
reached during transit could have a deleterious or prolific effect on
the bacterial cells present in the samples such that the samples may no
longer represent the microbial content of the water at the time of
sample collection.
    EPA recognizes that requiring the samples under the proposed RTCR
to be held at 10 degrees C or less, but above

freezing, would result in an increased cost to the water systems (for
shipping, supplies, etc.), but believes the extra burden may be
warranted. EPA is seeking public comment on whether this passage should
remain as is in the current TCR or whether the RTCR should require that
the samples collected for compliance with this regulation be shipped in
cold conditions, i.e., requiring a temperature of 10 degrees C or less,
but above freezing to be maintained for better sample preservation. EPA
also welcomes comments and supporting data on what the acceptable
temperature range should be when samples are in transit.

B. Proposed Compliance Date

    Consistent with SDWA section 1412(b)(10), EPA proposes that the
compliance date of the final RTCR be three years from the date on which
the regulation is promulgated (i.e., the publication date of the final
rule in the Federal Register). PWSs must comply with the requirements
of the rule by the compliance date.
    EPA believes that capital improvements generally are not necessary
to ensure compliance with the proposed RTCR. However, a State may allow
individual systems up to two additional years to comply with the RTCR
if the State determines that additional time is necessary for capital
improvements, in accordance with SDWA section 1412(b)(10).
    EPA requests comment on the proposed compliance date of the
proposed RTCR.

C. Links to Other Drinking Water Rule Requirements

    The proposed RTCR recognizes that existing NPDWRs contain linkages
among monitoring requirements in different rules. The current residual
disinfectant monitoring must be conducted at the same time and location
at which TCR samples are taken, as provided for in the Surface Water
Treatment Rule (SWTR) (USEPA 1989b, 54 FR 27486, June 29, 1989) and the
Stage 1 Disinfectants and Disinfection Byproducts Rule (Stage 1 DBPR)
(USEPA 1998a, 63 FR 69389, December 16, 1998). Under the GWR, TCR
distribution system monitoring results determine whether a system is
required to conduct source water monitoring. Under the SWTR, high
measurements of turbidity in an unfiltered subpart H system of this
part trigger additional total coliform samples. Sanitary survey
provisions exist in surface water and ground water drinking water
regulations. The proposed RTCR does not change the existing sanitary
survey requirements except to add the special monitoring evaluation
that States must conduct at systems serving 4,100 or fewer people.
These evaluations do not increase the burden to conduct sanitary
surveys because of the relatively simple nature of these systems and
their monitoring requirements.
1. SWTR, Stage 1 and Stage 2 DBPRs, ADWR
    After considering the possible linkages among the proposed RTCR and
the SWTR, Stage 1 DBPR, Stage 2 DBPR (USEPA 2006e, 71 FR 388, January
4, 2006), and Airline Drinking Water Rule (ADWR) (USEPA 2009), EPA has
concluded that the only necessary revision is to update the reference
to the current TCR at 40 CFR 141.21, which is superseded by 40 CFR part
141 subpart Y beginning three years following publication of the final
rule. EPA is also proposing several revisions to other NPDWRs,
discussed below, that are not necessary but would facilitate
implementation of all applicable NPDWRs.
2. GWR
    As with the other drinking water rules mentioned above, EPA is
proposing to update the references in the GWR to the current TCR at 40
CFR 141.21, which will be superseded by 40 CFR part 141 subpart Y.
3. Sanitary Surveys
    Sanitary survey requirements are not included in the proposed RTCR.
Under the current TCR, community water systems and non-community water
systems that serve 4,100 or fewer people are required to conduct
periodic sanitary surveys. Since the promulgation of the TCR in 1989,
new sanitary survey requirements for surface water systems and ground
water systems have been established for all system sizes and types
under the Interim Enhanced Surface Water Treatment Rule (IESWTR) (USEPA
1998b, 63 FR 69477, December 16, 1998) (40 CFR 142.16(b)(3)), and the
Ground Water Rule (GWR) (40 CFR 142.16(o)(2)(i)). Public water systems
began implementing the IESWTR sanitary survey requirements in 2001.
Therefore, for surface water systems, the current TCR sanitary survey
requirements have phased out since that time. Implementation of the GWR
sanitary survey requirements began in December 2009 for ground water
systems. Therefore, for ground water systems, the GWR sanitary survey
requirements will be in effect by the time the RTCR is finalized.

D. Best Available Technology (BAT)

1. Provisions

    The proposed RTCR would maintain the provisions set forth in 40 CFR
141.63(d) (proposed to be in Sec.  141.63(e)), regarding the best
technology, treatment techniques, or other means available for
achieving compliance with the MCL of either total coliforms or E. coli.
EPA is proposing the following modifications:
     40 CFR 141.63(d)(1) (proposed Sec.  141.63(e)(1)) would be
modified by replacing ``coliforms'' with ``fecal contaminants.''
     40 CFR 141.63(d)(3) (proposed Sec.  141.63(e)(3)) would be
modified by including ``cross connection control'' in the list of
proper maintenance practices for the distribution system.
     40 CFR 141.63(d)(4) (proposed Sec.  141.63(e)(4)) would be
modified by including the subparts P, T, and W that describe filtration
and/or disinfection of surface water, and subpart S for disinfection of
ground water.
2. EPA's Rationale
    a. Change ``coliform'' to ``fecal contaminants.'' This change
reflects the approach of the proposed RTCR that the presence of total
coliforms does not necessarily have a direct public health implication.
Instead, total coliform is used as an indicator of a potential pathway
of contamination within a treatment technique requirement. For
additional discussion on this topic, see section III.A.2 of this
preamble.
    b. Inclusion of cross connection control. EPA believes that adding
cross connection control to the list of proper maintenance practices
for distribution systems is appropriate because of the significant
contribution of cross connections and backflow to waterborne disease
outbreaks. From 1981 to 1998, the CDC documented 9, 734 detected and
reported illnesses from 57 waterborne outbreaks related to cross
connections (NRC 2006). From 1970 to 2001, approximately 12,000
illnesses resulted from 459 incidents of waterborne outbreaks from
backflow events (NRC 2006).
    c. Addition of other relevant subparts of 141. This change adds
references to subparts that contain provisions for the other drinking
water rules promulgated since 1989 when the TCR was promulgated (in
particular, subpart P for the IESWTR, subpart S for the GWR, subpart T
for the Long Term Enhanced Surface Water Treatment Rule (USEPA 2002, 67
FR 1812, January 14, 2002, and subpart W for the Long Term 2 Enhanced
Surface Water Treatment Rule (USEPA 2006d, 71 FR 654, January 5,

2006)). These drinking water rules contain updated filtration and
disinfection standards that were not part of the current TCR when it
was promulgated in 1989.
3. Request for Comment
    EPA requests comment on the modifications to the existing BATs and
whether there is a need to add or otherwise update the list of BATs.

E. Variances and Exemptions

1. Provisions
    EPA is proposing to not allow variances or exemptions to the E.
coli MCL. EPA is also proposing to eliminate the variance provisions in
40 CFR 141.4(b) that allow systems to demonstrate to the State that the
violation of the monthly/non-acute total coliform MCL is due to biofilm
and not fecal or pathogenic contamination. This change will also result
in a parallel change in 40 CFR 142.63(b).
2. EPA's Rationale
    Under the proposed RTCR, E. coli is used as an indicator of fecal
contamination that may contain waterborne pathogens. To the extent a
variance or exemption would permit the continued presence of E. coli,
the potential for pathogens to be present also would remain. EPA
believes that water which exceeds the MCL for E. coli poses an
unreasonable risk to public health. Therefore, EPA is not allowing any
variances or exemptions to the E. coli MCL. This provision is
consistent with the existing requirement, since the provision that
allows variances applies only to the monthly/non-acute total coliform
MCL violation and not to the acute violation associated with the
presence of E. coli.
    Under the current TCR, EPA allows variances to the MCL for total
coliforms when a system has demonstrated to the State that the
violation of the total coliform MCL is due to a persistent growth of
total coliforms in the distribution system (i.e., biofilm) rather than
fecal or pathogenic contamination, a treatment lapse or deficiency, or
a problem in the operation or maintenance of the distribution system.
    EPA is proposing to eliminate the variance in 40 CFR 141.4(b)
because under the proposed RTCR, there would no longer be an MCL for
total coliforms (see section III.A.2 of this preamble). The current TCR
MCL for total coliforms was based on the presence or absence of total
coliforms in a sample (see 40 CFR 141.63 for details). In the proposed
RTCR, the presence of total coliforms at a certain level requires the
system to comply with the coliform treatment technique requirements
(see section III.A.5 of this preamble). The assessment and corrective
action requirements under this proposed rule include the possibility of
recognizing that the total coliform presence is associated with
biofilm. EPA plans to include this information in a new assessment and
corrective action guidance manual related to the RTCR.
3. Request for Comment
    EPA requests comment on its proposal to allow no variance or
exemption to the E. coli MCL and to eliminate the variance provisions
associated with the monthly/non-acute total coliform MCL.

F. Request for Comment on Other Issues Related to the Proposed RTCR

1. Consistency Between the Proposed RTCR and the GWR
    EPA requests comment on the need for general consistency between
the proposed RTCR and the GWR. Please provide specific examples. For
example, under the current TCR, States are required to keep records of
their decision to either waive or extend the 24-hour limit for
collecting samples (that is, for repeat samples following a total
coliform-positive sample, or for follow-up samples after high levels of
turbidity) (see 40 CFR 142.14(a)(5)(i)(A) and 142.14(a)(5)(ii)(D)). The
proposed RTCR also requires States to keep records of decisions to
either waive or extend the 24-hour limit for repeat samples following a
total coliform-positive sample, for samples following invalidation, or
for follow-up samples after high levels of turbidity (see Sec. Sec.
142.14(a)(10)(i)(A) and 142.14(a)(10)(ii)(D) of the proposed RTCR).
Under the GWR, there are no recordkeeping requirements for the decision
to waive or extend the 24-hour limit. Instead, the GWR includes special
primacy requirements to describe criteria the State will use to extend
the 24-hour limit (see 40 CFR 142.16(o)(3)(i)). EPA requests comment on
whether it is appropriate to have States describe their criteria for
waiving or extending the 24-hour limit as a primacy condition, or
instead have States keep records of decisions to waive and/or extend
the 24-hour limit.
2. Storage Tank Inspection and Cleaning
    EPA requests comment on the value and cost of periodic storage tank
inspection and cleaning. There are instances of storage tanks being the
source of waterborne disease outbreaks at PWSs. In December 1993, a
Salmonella typhimurium outbreak in Gideon, Missouri resulted in over
600 people affected by diarrhea, 31 cases of laboratory-confirmed
salmonellosis and seven deaths of nursing home residents who had
exhibited diarrheal illness (four deaths were confirmed by culture).
The larger of the two storage tanks had a breach in the roof hatch that
allowed pigeon droppings to be carried into the tank and likely
accumulated in the several inches of sediment. This contaminated
sediment, more than likely, was pulled into the distribution system by
a flushing program that drained the tank (Clark et al. 1996).
Salmonella typhimurium was isolated from the sediment of one of the
towers, and tap water tested positive for fecal coliforms (CDC 1996).
    In March 2008, Alamosa, Colorado (with a population of about 9,000
people) experienced a waterborne disease outbreak associated with
Salmonella. The report released by the Colorado Department of Public
Health and Environment (Falco and Williams 2009) indicated that the
outbreak resulted in 442 reported cases of illnesses, 122 of which were
laboratory confirmed, and one fatality. The State epidemiologist
estimated that a total of 1,300 people may have been ill. Two storage
tanks in Alamosa had several inches of sediment and breaches; one tank
had breaches large enough for birds and animals to enter. Some of the
key factors that contributed to these two outbreaks include significant
levels of sediment (several inches to feet) and the presence of
breaches of the integrity of the storage tank.
    Sediment accumulation occurs within storage facilities due to
quiescent conditions which promote particle setting. Over time sediment
continues to accumulate in a tank, even if the finished water is
consistently treated to below 0.1 nephelometric turbidity unit (NTU).
For surface water systems, it is not uncommon to have \1/4\ to \1/2\
inch or more of sediment accumulate after two to three years (Kirmeyer
et al. 1999). While there are no turbidity regulations for ground water
systems (except for ground water under the direct influence of surface
water (GWUDI)), the levels of turbidity can be significant in the water
pumped from an aquifer. Sand particles, if allowed to accumulate,
provide pore spaces that house diverse populations of biota (which may
include pathogenic microorganisms) (Kirmeyer et al. 1999; van der Kooij
2003). Periodic high flows in the storage tank may scour, stir up, and
suspend the sediment (along with entrapped bacteria and pathogens) and
carry it into the distribution system, with greater accumulation of
sediment

being a more significant concern. Other water quality problems
associated with sediment accumulation include increased disinfectant
demand and disinfection byproduct formation.
    The storage tank's vulnerability to contamination increases when
breaches of the storage tank allow insects, animals, and birds and
their associated diseases to enter. Contamination from bird and other
animal excrement can potentially transmit disease-causing organisms to
the finished water. Waterfowl, for example, are known carriers of many
different waterborne pathogens including Vibrio cholerae (Ogg et al.
1989).
    Based on the potential public health implications associated with
poorly maintained storage tanks (e.g., as indicated by significant
sediment accumulation and breaches), EPA is interested in receiving
comments and supporting information regarding the state and condition
of tanks that have been cleaned and inspected, costs of storage tank
inspection and cleaning, and how public health can be better protected.
EPA requests information on whether there are States that recommend or
require periodic inspection and cleaning of storage tanks. If so, what
are the requirements, the frequency of inspection and cleaning, and how
successful are they? Are inspections and cleaning done by individual
PWSs or by contractors?
3. States Under EPA Direct Implementation
    EPA does not have the authorities provided to other primacy
agencies under 40 CFR part 142 to use in implementing rules in direct
implementation entities (e.g., Tribal systems and Wyoming). To provide
EPA the flexibility of other primacy agencies to modify monitoring
requirements as necessary to protect public health (e.g., to require
more stringent monitoring or to develop criteria such as those that
primacy States develop under the special primacy conditions requirement
in 40 CFR 142.16) and facilitate implementation of this rule. EPA is
requesting comment on whether the Agency should have the same
authorities specified in subpart Y, as States have in 40 CFR 142.16,
for PWSs for which the Agency has direct implementation
responsibilities. EPA is requesting comment on whether this authority
should be added to subpart Y specifically.

G. Limitations to the Public Comment on the Proposed RTCR

    The proposed revisions to other drinking water regulations (SWTR,
Stage 1 DBPR, Stage 2 DBPR, and ADWR) are made solely to update the
reference to the current TCR at 40 CFR 141.21, which will be superseded
by 40 CFR part 141 subpart Y beginning three years following
publication of the final rule. This proposed rule would not change any
substantive requirements of those rules and EPA is not soliciting
public comments on those rules other than their proposed revised
references to the current TCR or any other references to the current
TCR that EPA may need to revise.

IV. State Implementation

    The proposed RTCR provides States with flexibility to implement the
requirements of the rule in a manner that maximizes the efficiency of
the rule for the States and water systems while increasing the
effectiveness of the rule to protect public health. While the proposed
rule provides some reduction in monitoring relative to the current TCR,
overall, the proposed rule is more stringent and better protects public
health. As a result, States must adopt these revisions, when final, or
adopt or maintain more stringent requirements, in order to maintain
primacy. This section describes the regulations and other procedures
and policies States must adopt in order to obtain primacy to implement
the RTCR, if finalized as proposed today.
    SDWA section 1413 establishes requirements that States or eligible
Indian Tribes must meet to assume and maintain primary enforcement
responsibility (primacy) for its PWSs. These requirements include:
     Adopting drinking water regulations that are no less
stringent than Federal drinking water regulations;
     Adopting and implementing adequate procedures for
enforcement;
     Keeping records and making reports available on activities
that EPA requires by regulation;
     Issuing variances and exemptions (if allowed by the
State), under conditions no less stringent than allowed under SDWA; and
     Adopting and being capable of implementing an adequate
plan for the provisions of safe drinking water under emergency
situations.
    States may adopt more stringent requirements (e.g., requiring all
systems to conduct routine monthly monitoring). Many States have used
this authority in the past to improve public health protection and/or
simplify implementation.
    Section 1413(a)(1) of SDWA provides two years (plus up to two more
years if the Administrator approves) after promulgation of the final
RTCR for the State to adopt corresponding drinking water regulations in
order to obtain primacy for the final RTCR. To implement the final
RTCR, States would be required to adopt or maintain requirements that
are at least as stringent as the following revisions to 41 CFR part
141:
     Section 141.4--Variances and exemptions (if allowed by the
State).
     Section 141.21--Coliform sampling.
     Section 141.52--Maximum contaminant level goals for
microbiological contaminants.
     Section 141.63--Maximum contaminant levels (MCLs) for
microbiological contaminants.
     Section 141.74--Analytical and monitoring requirements.
     Section 141.132--Monitoring requirements.
     Subpart 141.153--Content of the reports.
     Subpart 141.202--Tier 1 Public Notice--Form, manner, and
frequency of notice.
     Subpart 141.203--Tier 2 Public Notice--Form, manner, and
frequency of notice.
     Subpart 141.204--Tier 3 Public Notice--Form, manner, and
frequency of notice.
     Subpart O--Consumer Confidence Reports, Appendix A,
Regulated Contaminants.
     Subpart Q--Public Notification of Drinking Water
Violations, Appendix A, NPDWR Violations and Other Situations.
     Subpart Q--Public Notification of Drinking Water
Violations, Appendix B, NPDWR Violations and Other Situations.
     Subpart Y--Revised Total Coliform Rule.
    EPA's regulation at 40 CFR part 142 sets out the specific program
implementation requirements for States to obtain primacy for the public
water supply supervision program as authorized under SDWA section 1413.
In addition to adopting basic primacy requirements specified in 40 CFR
part 142, States may be required to adopt special primacy provisions
pertaining to specific regulations where implementation of the rule
involves activities beyond general primacy provisions. States must
include these regulation-specific provisions in their application for
approval of their program revision. States must continue to meet all
other conditions of primacy for all other rules in 40 CFR part 142.
Primacy requirements for the proposed RTCR are described below.
    The advisory committee recognized that this rule will require more
tracking to ensure effective implementation.

Therefore, EPA plans to release an upgrade to SDWIS/State and SDWIS/FED
(the State and Federal versions of the Safe Drinking Water Information
System, respectively) within 18 months of final rule promulgation to
accommodate monitoring data, tracking, compliance determinations and
reporting of all rule related requirements, as appropriate.

A. State Special Primacy Requirements

    To ensure that a State program includes all the elements necessary
for an effective and enforceable program under the proposed RTCR, a
State primacy application must include a description of how the State
will perform the following:
     Sample Siting Plans--States must describe the frequency
and process used to review and revise sample siting plans in accordance
with 40 CFR 141, subpart Y to determine adequacy.
     Reduced Monitoring Criteria--The primacy application must
indicate whether the State will adopt the reduced monitoring provisions
of subpart Y. If the State adopts the reduced monitoring provisions, it
must describe the specific types or categories of water systems that
will be covered by reduced monitoring and whether the State will use
all or a reduced set of the optional criteria. For each of the reduced
monitoring criteria, both mandatory and optional, the State must
describe how the criteria will be evaluated to determine when systems
qualify.
     Assessments and Corrective Actions--States must describe
their process to implement the new assessment and corrective action
phase of the rule. The description must include examples of sanitary
defects, examples of assessment forms or formats, and methods that
systems may use to consult with the State on appropriate corrective
actions.
     Invalidation of routine and repeat samples collected under
subpart Y--States must describe their criteria and process to
invalidate total coliform-positive and E. coli-positive samples under
subpart Y. This includes criteria to determine if a sample was
improperly processed by the laboratory, reflects a domestic or other
non-distribution system plumbing problem or reflects circumstances or
condition that does not reflect water quality in the distribution
system.
     Approval of individuals allowed to conduct subpart Y Level
2 assessments--States must describe their criteria and process for
approval of individuals allowed to conduct subpart Y Level 2
assessments.
     Special monitoring evaluation--States must describe how
they will perform special monitoring evaluations during sanitary
surveys for ground water systems serving 1,000 or fewer people to
determine whether systems are on an appropriate monitoring schedule.
     Seasonal systems--States must describe how they will
identify seasonal systems, how they will determine when systems on less
than monthly monitoring must monitor, and what will be the seasonal
system start-up provisions.
     Additional criteria for reduced monitoring--States must
describe how they will require systems on reduced monitoring to
demonstrate:
    --Continuous disinfection entering the distribution system and a
residual in the distribution system;
    --Cross connection control;
    --Other enhancements to water system barriers; and
    --Procedures for seasonal systems to start up operations at the
beginning of each season.

B. State Recordkeeping Requirements

    The current regulations in 40 CFR 142.14 require States with
primacy to keep records, including: Analytical results to determine
compliance with MCLs, MRDLs, and treatment technique requirements; PWS
inventories; State approvals; enforcement actions; and the issuance of
variances and exemptions. The proposed RTCR requires States to keep
additional records, including all supporting information and an
explanation of the technical basis for each decision as follows.
Records of the following decisions or activities must be retained for
five years, consistent with recordkeeping requirements for existing
regulations:
     Any decision to waive the 24-hour time limit for
collecting repeat samples after a total coliform-positive routine
sample, or to extend the 24-hour limit for collection of samples
following invalidation, or for an unfiltered subpart H system of this
part to collect a total coliform sample following a turbidity
measurement exceeding 1 NTU.
     Any decision to allow a system to waive the requirement
for three routine samples the month following a total coliform-positive
sample. The record of the waiver decision must contain all the items
listed in Sec. Sec.  141.854(j) and 141.855(f) of the proposed RTCR.
     Any decision to invalidate a total coliform-positive
sample. If the State decides to invalidate a total coliform-positive
sample as provided in Sec.  141.853(c)(1) of the proposed RTCR, the
record of the decision must contain all the items listed in that
paragraph.
     Completed and approved 40 CFR part 141 subpart Y
assessments, including reports from the system that corrective action
has been completed.

States must retain records of each of the following decisions in such a
manner so that each system's current status may be determined at any
time:
     Any decision to reduce the total coliform monitoring
frequency for a community water system serving 1,000 or fewer people to
less than once per month, as provided in Sec.  141.855(d) of the
proposed RTCR; and what the reduced monitoring frequency is. A copy of
the reduced monitoring frequency must be provided to the system.
     Any decision to reduce the total coliform monitoring
frequency for a non-community water system using only ground water and
serving 1,000 or fewer people to less than once per quarter, as
provided in Sec.  141.854(e) of the proposed RTCR, and what the reduced
monitoring frequency is. A copy of the reduced monitoring frequency
must be provided to the system.
     Any decision to reduce the total coliform monitoring
frequency for a non-community water system using only ground water and
serving more than 1,000 persons during any month the system serves
1,000 or fewer people, as provided in Sec.  141.857(d) of the proposed
RTCR. A copy of the reduced monitoring frequency must be provided to
the system.
     Any decision to waive the 24-hour limit for taking a total
coliform sample for a public water system that uses surface water, or
ground water under the direct influence of surface water, and that does
not practice filtration in accordance with part 141, subparts H, P, T,
and W, and that measures a source water turbidity level exceeding 1 NTU
near the first service connection.
     Any decision to allow a public water system to forgo E.
coli testing on a total coliform-positive sample if that system assumes
that the total coliform-positive sample is E. coli- positive.

C. State Reporting Requirements

    EPA currently requires at 40 CFR 142.15 that States report to EPA
information such as violations, variance and exemption status, and
enforcement actions. The proposed RTCR requires States to develop and
maintain a list of public water systems that the State is allowing to
monitor less frequently than once per month for community water systems
or less frequently than once per quarter for non-community water

systems, including the compliance date (the date that reduced
monitoring was approved) of the reduced monitoring requirement for each
system.

D. Interim Primacy

    On April 28, 1998, EPA amended its State primacy regulations at 40
CFR 142.12 to incorporate the new process identified in the 1996 SDWA
Amendments for granting primary enforcement authority to States while
their applications to modify their primacy programs are under review
(USEPA 1998c, 63 FR 23361, April 28, 1998). The new process grants
interim primary enforcement authority for a new or revised regulation
during the period in which EPA is making a determination with regard to
primacy for that new or revised regulation. This interim enforcement
authority begins on the date of the primacy application submission or
the effective date of the new or revised State regulation, whichever is
later, and ends when EPA makes a final determination. However, this
interim primacy authority is only available to a State that has primacy
(including interim primacy) for every existing NPDWR in effect when the
new regulation is promulgated.
    As a result, States that have primacy (including interim primacy)
for every existing NPDWR already in effect may obtain interim primacy
for the RTCR, beginning on the date that the State submits the
application for this rule to EPA, or the effective date of its revised
regulations, whichever is later. A State that wishes to obtain interim
primacy for future NPDWRs must obtain primacy for this rule.

E. Request for Comment

    EPA requests comment on the adequacy of the proposed RTCR
requirements for State implementation, including but not limited to
State special primacy requirements and State reporting and
recordkeeping requirements. Specifically, EPA requests comment on
whether there are any requirements that should be added to assure
proper State oversight, or any that can be removed without detriment to
implementation of the rule.

V. Distribution System Research and Information Collection Activities

A. Research and Information Collection Partnership

    The advisory committee recommended that a Research and Information
Collection Partnership (RICP) be formed to inform and support the
drinking water community in developing future national risk management
decisions pertaining to drinking water distribution systems. The
advisory committee recommended seven priority areas for research and
information collection. These seven priority areas are: (1) Cross-
connection and backflow of contaminated water; (2) contamination due to
storage facility design, operation, or maintenance; (3) contamination
due to main installation, repair, or rehabilitation practices; (4)
contaminant intrusion due to pressure conditions and physical gaps in
distribution system infrastructure; (5) significance and control of
biofilm and microbial growth; (6) nitrification issues that lead to
public health effects; and (7) accumulation and release of contaminants
from distribution system scales and sediments (USEPA 2008c, AIP p. 30).
    In January 2009, EPA and the Water Research Foundation (WRF or the
Foundation) signed a memorandum of understanding (MOU) to form the RICP
in response to recommendations from the advisory committee contained in
the AIP (USEPA and WRF 2009). The MOU conveys the partners' agreement
to collaborate and identify, define, prioritize, coordinate, and
communicate critical decision-relevant distribution system research and
information collection needs of the drinking water community. The RICP
is directed by a steering committee comprised of nine members: Three
members from EPA, three members from water utilities, and three
additional members representing the public health, environmental
advocate, and State regulator perspectives.
    The partners are developing a distribution system research and
information collection agenda that focuses on characterizing and
reducing public health risks. The identified priority information and
research will allow better understanding and management of potential
public health risks from drinking water distribution systems. See
http://www.epa.gov/safewater/disinfection/tcr/regulation_revisions_
tcrdsac.html for further information on this effort.

B. Distribution System Optimization Activities

    As part of the AIP, the advisory committee encouraged ``the
development of national and regional distribution system optimization
partnerships that focus on protecting the integrity of drinking water
quality once it is delivered to the distribution system. The purpose of
the partnerships should be to inform and inspire proactive systems to
implement best management practices that emphasize protection of public
health. These partnerships, comprised, for example, of representatives
from utilities, communities, academia, and regulatory organizations
could develop continuous improvement programs that encompass water
distribution optimization principles and practices for system design,
operations, and maintenance. These partnerships should foster
continuous review of distribution system issues and should define
excellence in distribution system operation in terms of processes,
systems, procedures, as well as measures. The optimization partnerships
should encourage voluntary program participation of all drinking water
utilities regardless of system size'' (USEPA 2008c, AIP p. 25).
    EPA is aware of two distribution system optimization programs that
are currently being developed. EPA and the Foundation are concurrently
developing distribution system optimization programs that focus on
protecting public health in the distribution system. Developmental
activities to support these efforts are occurring through the EPA's
National Area Wide Optimization Program (AWOP) and the Foundation's
project 4109. While these programs are being developed
independently with differing measures of performance, both are founded
on the optimization principles of improving water systems, and go
beyond the regulatory requirements, while using existing staff and
facilities. These principles and practices are currently being used
through the in-plant treatment optimization programs operated through
AWOP and the American Water Works Association's (AWWA) Partnership for
Safe Water (the Partnership). For more information on the Partnership
for Safe Water, see (http://www.awwa.org/Resources/
PartnershipforSafeWater.cfm?ItemNumber=3787&navItemNumber=33969).
    The goal of EPA's optimization program is to protect public health
by addressing both the technical and management issues that limit the
water system's ability to meet water quality performance goals. EPA has
started developing a distribution system optimization program, which is
currently focused on improving water treatment plant finished water
quality while maintaining disinfectant residual and minimizing
disinfection byproduct formation in the distribution system. Future
work may focus on other water quality parameters or issues of concern.
An outcome of this effort will be the identification of the key
technical and management skills, practices, and tools

that a water system should implement to achieve long-term distribution
system optimization. Ultimately, participating AWOP States will be
introduced to distribution system optimization methods developed by
EPA. At this time, additional development activities are needed before
a distribution system optimization program will be available for State
implementation.
    In 2007, the Foundation initiated project 4109 to identify
a limited number of straightforward criteria that can be used by water
utilities to measure distribution system optimization performance and
to develop a self-assessment approach using standards of excellence.
The results from this project will also be used to expand the
Partnership for Safe Water Program treatment plant optimization program
into distribution system optimization. The Foundation anticipates
project 4109 to be completed by early 2010. With the results
of project 4109, the Partnership anticipates finalizing a
preliminary set of optimization goals and a model assessment process in
calendar year 2010. Prior to finalizing the goals and assessment
process, the Partnership will conduct trials at several volunteer
utilities. The optimization goals and assessment process will be
evaluated and refined based on those trials prior to consideration by
the Partnership for adoption and implementation. AWWA anticipates that
applications for the Partnership's Distribution System Optimization
Program will be available in calendar year 2011.

C. Request for Comment

    EPA requests comment about these distribution system optimization
projects and information about or suggestions for other possible
approaches to distribution system optimization.

VI. Economic Analysis (Health Risk Reduction and Cost Analysis)

    This section summarizes the Health Risk Reduction and Cost Analysis
(HRRCA) in support of the proposed RTCR as required by section
1412(b)(3)(C) of the SDWA. EPA has prepared the RTCR Economic Analysis
(EA) (USEPA 2010a) to comply with this requirement. The EA document for
the proposed RTCR is available in the docket and is also published on
the government's Web site at http://www.regulations.gov.
    The HRRCA consists of seven elements: (1) quantifiable and
nonquantifiable health risk reduction benefits; (2) quantifiable and
nonquantifiable health risk reduction benefits from reductions in co-
occurring contaminants; (3) quantifiable and nonquantifiable costs that
are likely to occur solely as a result of compliance; (4) incremental
costs and benefits of rule options; (5) effects of the contaminant on
the general population and sensitive subpopulations including infants,
children, pregnant women, elderly, and individuals with a history of
serious illness; (6) any increased health risks that may occur as a
result of compliance, including risks associated with co-occurring
contaminants; and (7) other relevant factors such as uncertainties in
the analysis and factors with respect to the degree and nature of risk.
See SDWA section 1412(b)(3)(C). A summary of these elements is provided
in this section of the preamble, and a complete discussion can be found
in the Proposed RTCR EA (USEPA 2010a).
    The benefits described in this section are discussed qualitatively,
and reductions in detection of total coliforms and E. coli and in Level
2 assessments are used to describe the benefits, as described later in
this section. The costs discussed in this section are presented as
annualized present values in 2007 dollars. Both benefit and cost
measures are adjusted using social discounting. In social discounting,
future values of a rule's or policy's effects are multiplied by
discount factors. The discount factors reflect both the amount of time
between the present and the point at which these events occur and the
degree to which current consumption is more highly valued than future
consumption (USEPA 2000c). This process allows comparison of cost and
benefit streams that are variable over a given time period. EPA uses
social discount rates of both three percent and seven percent to
calculate present values from the stream of benefits and costs and also
to annualize the present value estimates. Historically, the use of
three percent is based on rates of return on relatively risk-free
financial instruments, while seven percent is generally an estimate of
before-tax rate of return to incremental private investment. For
further information, see USEPA 2000c and OMB 1996.
    In the Proposed RTCR EA (USEPA 2010a), EPA also presents the
undiscounted stream of benefits and costs over the 25-year time frame
(i.e., the year-to-year realization of benefits and costs presented in
constant terms).
    The time frame used for both benefit and cost comparisons in this
rule is 25 years. This time interval accounts for rule implementation
activities occurring soon after promulgation (e.g., States adopting the
criteria of the regulation) and the time for different types of
compliance actions (e.g., assessments and corrective actions) to be
realized up through the 25th year following rule promulgation.
    EPA was unable to quantify health benefits for the proposed RTCR
because there are insufficient data reporting the co-occurrence in a
single sample of fecal indicator E. coli and pathogenic organisms. In
addition, the available fecal indicator E. coli data from the Six-Year
Review 2 dataset (USEPA 2010e) described in this preamble were limited
to presence-absence data because the current TCR requires only the
reporting of presence or absence of fecal indicator E. coli using EPA-
approved standard methods. However, as discussed in chapter 6 of the
Proposed RTCR EA (USEPA 2010a), even though health benefits could not
be directly quantified, the potential benefits from the proposed RTCR
include avoidance of a full range of health effects from the
consumption of fecally contaminated drinking water, including the
following: acute and chronic illness, endemic and epidemic disease,
waterborne disease outbreaks, and death. Also, since fecal
contamination may contain waterborne pathogens including bacteria,
viruses, and parasitic protozoa, in general, a reduction in fecal
contamination should reduce the risk from these other contaminants.
    The net costs of the rule stem mostly from the new assessment and
corrective action requirements as well as the revised monitoring
provisions described earlier in this preamble.
    This section of the preamble includes elements as follows: (A)
Regulatory Options Considered, (B) Major Sources of Data and
Information used in Supporting Analyses, (C) Occurrence and Predictive
Modeling, (D) Baseline Profiles, (E) Anticipated Benefits of the
Proposed RTCR, (F) Anticipated Costs of the Proposed RTCR, (G)
Potential Impact of the Proposed RTCR on Households, (H) Incremental
Costs and Benefits, (I) Benefits from Simultaneous Reduction of Co-
occurring Contaminants, (J) Change in Risk from Other Contaminants, (K)
Effects of Fecal Contamination and/or Waterborne Pathogens on the
General Population and Sensitive Subpopulations, (L) Uncertainties in
the Benefit and Cost Estimates for the Proposed RTCR, (M) Benefit Cost
Determination for the Proposed RTCR, and (N) Request for Comment.

A. Regulatory Options Considered

    EPA evaluated the following three regulatory options as part of
this revised

rule proposal: (1) The current TCR option, (2) the AIP option, and (3)
an Alternative option. EPA discusses the three regulatory options
briefly in this preamble and in greater detail in chapter 3 of the
Proposed RTCR EA (USEPA 2010a).
    First, the current TCR option reflects EPA's understanding of how
the current TCR (USEPA 1989a, 54 FR 27544, June 29, 1989) is currently
being implemented. That is, the current TCR option is assumed to
include ``status quo'' PWS and State implementation practices. Next,
the AIP option is a revised TCR based on the recommendations of the
advisory committee. The provisions of this proposed rule are based on
the AIP option and are described in detail in section III of this
preamble. Third, the Alternative option parallels the AIP in most ways
but includes variations of some of the provisions that were discussed
by the advisory committee before consensus was reached on the AIP.
    The Alternative option differs from the AIP option in two ways.
First, under the Alternative option, at the compliance date all PWSs
are required to sample monthly for an initial period until they meet
the eligibility criteria for reduced monitoring. EPA assumes that
eligibility for reduced monitoring is determined during the next
sanitary survey following the RTCR compliance date. This more stringent
approach differs from the AIP option that allows PWSs to continue to
monitor at their current frequencies (with an additional annual site
visit or voluntary Level 2 assessment requirement for PWSs wishing to
remain on annual monitoring) until they are triggered into an increased
sampling frequency. Second, under the Alternative option, no PWSs are
allowed to reduce monitoring to an annual basis. EPA defined the
Alternative option this way and included it in the Proposed RTCR EA
(USEPA 2010a) to assess the relative impacts of a more stringent rule
and to better understand the balance between costs and public health
protection.
    To understand the relative impacts of the options, EPA gathered
available data and information to develop and provide input into an
occurrence and predictive model. EPA estimated both baseline conditions
and changes to these conditions anticipated to occur over time as a
result of these revised rule options. The analysis is described in more
detail in the Proposed RTCR EA (USEPA 2010a).

B. Major Sources of Data and Information Used in Supporting Analyses

    This section of the preamble briefly discusses the data sources
that EPA used in its supporting analyses for the proposed RTCR. For a
more detailed discussion, see chapter 4 of the Proposed RTCR EA (USEPA
2010a).
1. Safe Drinking Water Information System Federal Version Data
    Safe Drinking Water Information System Federal Version (SDWIS/FED)
is EPA's national regulatory compliance database for the drinking water
program and is the main source of PWS inventory and violation data for
the proposed RTCR baseline. SDWIS/FED contains information on each of
the approximately 155,000 active PWSs as reported by primacy agencies,
EPA Regions, and EPA headquarters personnel. SDWIS/FED includes records
of MCL violations and monitoring and reporting (MR) violations (both
routine and repeat and minor and major). It does not include sample
results. It also contains information to characterize the US inventory
of PWSs including system name and location, retail population served,
source water type (ground water (GW), surface water (SW), or ground
water under the direct influence of surface water (GWUDI)),
disinfection status, and PWS type (community water system (CWS),
transient non-community water system (TNCWS), and non-transient non-
community water system (NTNCWS)).
    To create the PWS and population baseline, EPA used the fourth
quarter of SDWIS/FED 2007 (USEPA 2007b), which was the most current PWS
inventory data available when EPA began developing the Proposed RTCR
EA. These data represent all current, active PWSs and the population
served by these systems.
    EPA also used the MCL violation data from SDWIS/FED to validate
model predictions for systems serving 4,100 or fewer people and to
predict E. coli (acute)---MCL violations (current TCR, AIP, and
Alternative option), total coliform (non-acute or monthly) MCL
violations (current TCR), and Level 1 and Level 2 assessment triggers
(AIP and Alternative option) for systems serving more than 4,100
people.
2. Six-Year Review 2 Data
    Through an Information Collection Request (USEPA 2006b), States
voluntarily submitted electronically available TCR monitoring data
(sample results) that were collected between January 1998 and December
2005. EPA requested the TCR monitoring results with the intent of
conducting analyses and developing models to assess the potential
impacts of changes to the current TCR. EPA received data from 46
States, Tribes, and territories. A Data Quality Report (USEPA 2010c)
describes how TCR monitoring data were obtained, evaluated, and
modified where necessary to make the database internally consistent and
usable for analysis. Exhibit 2.1 in the Data Quality Report provides a
complete list of States or territories that submitted data and a
description of the use of these data.
    In this EA, EPA included data from 37 primacy agencies (35 States
and 2 Tribes). Records included data for:
     PWS information (system type, population served, source
water type)
     Sample type (routine, repeat, special purpose)
     Analytical result
     Sampling location--entry point, distribution system and,
for repeat samples, original location, downstream, upstream, and other
     Analytical method
     Disinfectant residual data collected at TCR monitoring
sites
    As discussed in greater detail in section <IP_ADDRESS> of the Proposed
RTCR EA (USEPA 2010a), EPA used 2005 data exclusively in the analyses
supporting the proposed RTCR because the 2005 data set was the most
complete year of data among the Six-Year Review 2 data (USEPA 2010e).
The 2005 data was also the most recent data available suggesting that
it may be the most representative of present conditions.
    The Six-Year Review 2 data (USEPA 2010e) also informed EPA's
assumptions regarding the proportions of GWSs serving 1,000 or fewer
people that sample monthly, quarterly, or annually.
3. Other Information Sources
    Additional data and information sources included the Economic
Analysis for the Ground Water Rule (GWR EA) (USEPA 2006a), the
Technology and Cost Document for the Proposed Revised Total Coliform
Rule (proposed RTCR T&C document) (USEPA 2010b), the U.S. Census data,
and the knowledge and experience of stakeholders representing industry,
States, small systems, and the public.
    The GWR EA provided occurrence information on E. coli in the source
water of ground water PWSs for modeling the triggered monitoring
component of GWR and informed the assumptions on the distribution of
corrective actions taken in response to the presence of E. coli in the
source water. As discussed in section VI.C.1 of

this preamble, the model developed for this economic analysis considers
the effect of GWR both before and during implementation of the proposed
revised rule. The proposed RTCR T&C document included estimates of unit
costs for the major components of the proposed RTCR including labor,
monitoring, assessments, and corrective actions. U.S. Census data were
used to estimate population per household and to characterize sensitive
subpopulations. Lastly, knowledge and experience from stakeholders
helped to inform the assumptions that were made for the analysis.
    A more detailed discussion of these data sources and how EPA used
them are included in the Proposed RTCR EA (USEPA 2010a).

C. Occurrence and Predictive Modeling

    EPA used the data to develop an occurrence and predictive model for
PWSs serving 4,100 or fewer people based primarily on the 2005 Six-Year
Review 2 data (USEPA 2010e). The model predicts changes in total
coliform and E. coli occurrence, Level 1 and Level 2 assessments (based
on simulated monitoring results), corrective actions, and violations
over time. EPA developed another, simpler, predictive model, for PWSs
serving more than 4,100 people, that predicts Level 1 and Level 2
assessments (based on 2005 violation data from SDWIS/FED), corrective
actions, and violations over time, but not total coliform and E. coli
occurrence. EPA modeled systems serving more than 4,100 people
separately because the Six-Year Review 2 data (USEPA 2010e) for larger
PWSs were not as robust as the data for the smaller systems. In
addition, while EPA is proposing new monitoring requirements for PWSs
serving 4,100 people or fewer, proposed monitoring requirements for
systems serving greater than 4,100 people remain essentially unchanged.
This section briefly discusses the structures of each of the two models
and how they used available data, information, and assumptions to make
predictions over time resulting from the proposed regulatory options.
    Chapter 5 of the Proposed RTCR EA (USEPA 2010a) includes a more
detailed description of the occurrence and predictive model used for
PWSs serving 4,100 or fewer people, and the other simpler predictive
model used for PWSs serving greater than 4,100 people.
1. Model Used for Public Water Systems Serving 4,100 or Fewer People
    The occurrence and predictive model used for PWSs serving 4,100 or
fewer people has two components. The first component of the model
characterized how the presence or positive rates of total coliform and
E. coli detections vary across the population of small (serving 4,100
or fewer people) public water systems in the U.S. These rates vary by
the type of sample (routine or repeat), by analyte (total coliforms or
E. coli), and by system type (CWS, NCWS, or TNCWS) and size. The second
component of the model used the total coliform and E. coli occurrence
distributions to simulate a set of nationally-representative systems
within the context of the three regulatory options (TCR, AIP, and
Alternative) to predict changes in total coliform and E. coli
occurrence, triggers, assessments, corrective actions over time, and
violations.
    The model assumed that the national occurrence of total coliforms
and E. coli has reached a steady state in recent years under the
current TCR. It assumed that cycles of normal deterioration and repair/
replacement are occurring at the individual system level. However, the
numbers of violations at the national level have remained relatively
unchanged. This assumption is based on evaluation of SDWIS/FED
violation data. Exhibit VI-1 presents the number of PWSs with TCR
violations over the last several years which shows that national
violation rates have remained relatively steady over the past several
years. Revisions to the TCR affect this steady state, likely resulting
in a reduction of the underlying occurrence and associated violations.
However, before the RTCR goes into effect, GWR implementation begins
which is also expected to affect the steady state.
[GRAPHIC] [TIFF OMITTED] TP14JY10.001

    To estimate the effects that GWR implementation is expected to have
on present steady state conditions, EPA used the occurrence and
predictive model to simulate five years of implementation of the
current TCR with the GWR, which became effective in December 2009. EPA
assumed these five years to account for the approximately two years
before the expected promulgation date of the final RTCR and an
additional three years after that until the RTCR effective date. The
assumptions made to account for the GWR are described in detail in the
Proposed RTCR EA (USEPA 2010a) and summarized in Exhibit VI-2.

      Exhibit VI-2--Summary of Major Assumptions for Simulating GWR
                             Implementation
------------------------------------------------------------------------
             GWR provision                Modeling approach/ assumption
------------------------------------------------------------------------
Triggered Monitoring: GWSs not           Current model used same
 providing 4-log treatment for viruses    probabilities used in GWR EA
 that have total coliform-positive        (USEPA 2006a) to predict
 samples under current TCR are required   whether source water samples
 to take source water samples and test    will be E. coli-positive.
 for fecal indicator. If the sample is   GWSs required to conduct
 positive, they must take an additional   corrective action due to
 5 source water samples (unless the       monitoring results will either
 State requires corrective action). If    install disinfection or
 any of these is positive, they must      implement a nondisinfecting
 conduct corrective action.               corrective action as described
                                          in Proposed RTCR EA (USEPA
                                          2010a).
                                         GWSs installing disinfection
                                          will draw from the probability
                                          distributions for total
                                          coliforms and E. coli for
                                          disinfected systems for the
                                          remainder of analysis.
                                         GWSs implementing a
                                          nondisinfecting corrective
                                          action will experience no
                                          positive samples for the
                                          remainder of the year plus two
                                          additional years and will
                                          experience a 75 \1\ percent
                                          reduction in occurrence for
                                          five additional years.

Sanitary Surveys: GWR includes Federal   Model did not explicitly
 sanitary survey requirements for all     simulate sanitary surveys or
 GWSs, and requires States to perform     their results. Rather, it
 regular comprehensive sanitary surveys   assumed that the new sanitary
 including eight critical elements.       survey provisions will result
                                          in 10 percent \2\ reduced
                                          occurrence of total coliforms
                                          universally for entire
                                          analysis.
Compliance Monitoring: GWSs that         Model did not explicitly
 provide 4-log treatment for viruses      simulate compliance
 must demonstrate that they are           monitoring. Rather, it assumed
 providing this level of treatment by     that the provision will result
 conducting compliance monitoring..       in 10 percent \3\ reduced
                                          occurrence of total coliforms
                                          for those GWSs that are
                                          conducting compliance
                                          monitoring once assumed 4-log
                                          treatment for viruses begins
------------------------------------------------------------------------
1, 2, 3 Assumption reflects EPA best professional judgment.
Source: Proposed RTCR EA (USEPA 2010a) as informed by GWR EA (USEPA
  2006a).

    Actual reductions in occurrence that are expected to result from
the implementation of GWR requirements may differ from what is
presented here. However, based on assumptions used in this model, the
analysis of how the AIP and Alternative option perform relative to each
other are not affected.
    In addition to capturing the effect of implementation of GWR
requirements with the current TCR for a five-year period of analysis,
the model captures an additional 25 years with the current TCR, the AIP
option, and the Alternative option. Along with changes in total
coliform and E. coli occurrence, the model predicts behavioral changes:
The number of Level 1 and Level 2 assessments (and associated Level 1
or Level 2 corrective actions) to be performed, further resulting
adjustments to occurrence, and changes in sampling regimens as systems
qualify for reduced monitoring requirements. The assumptions used to
simulate RTCR implementation are detailed in the Proposed RTCR EA
(USEPA 2010a) and summarized in Exhibit VI-3.

 Exhibit VI-3--Summary of Major Assumptions for Simulating Proposed RTCR
                             Implementation
------------------------------------------------------------------------
   Proposed RTCR provision            Modeling approach/assumption
------------------------------------------------------------------------
Level 1 Assessment...........  Model simulates sampling and sampling
                                results and determines which PWSs will
                                be triggered to conduct an assessment.
                               Sanitary defects are found in 10 percent
                                \1\ of assessments (represents net
                                increase over current TCR).
                               All sanitary defects are corrected. Model
                                selects from distribution of potential
                                corrective actions as explained in
                                chapter 7 of the Proposed RTCR EA (USEPA
                                2010a).
                               PWSs implementing a corrective action as
                                a result of a Level 1 assessment
                                experience no positive samples for the
                                remainder of the year plus one
                                additional year and will experience 50
                                percent \2\ reduction in occurrence for
                                three additional years.
Level 2 Assessment...........  Model simulates sampling and sampling
                                results and determines which PWSs will
                                be triggered to conduct an assessment.
                               Sanitary defects will be found in 10
                                percent \3\ of assessments (represents
                                net increase over current TCR).
                               All sanitary defects are corrected. Model
                                selects from distribution of potential
                                corrective actions as explained in
                                chapter 7 of the Proposed RTCR EA (USEPA
                                2010a).
                               PWSs implementing a corrective action as
                                a result of a Level 2 assessment will
                                experience no positive samples for the
                                remainder of the year plus two
                                additional years and will experience 75
                                percent \4\ reduction in occurrence for
                                five additional years.
------------------------------------------------------------------------
1 3 Assumption based on conversation with State representatives with on-
  the-ground experience.
2 4 Assumption reflects EPA best professional judgment.

Note: EPA recognizes that there is a large uncertainty with the
  assumptions. Sensitivity analyses showed that the fundamental
  conclusions of the economic analysis do not change over a wide range
  of assumptions tested.
Source: Proposed RTCR EA (USEPA 2010a).

    EPA made different assumptions for the effectiveness of assessments
and subsequent corrective actions to account for the differences
between the two types of assessments. The Level 2 assessment is a more
comprehensive investigation that may result in finding more substantial
problems than what may be found during a Level 1 assessment, and for
that reason the corrective actions that result from a Level 2
assessment were modeled to have bigger and longer lasting effects than
those of the Level 1 assessments. EPA conducted sensitivity analyses
around the key assumptions summarized in Exhibit VI-2 as discussed in
section VI.L of this preamble.
2. Model Used for Public Water Systems Serving More Than 4,100 People
    For systems serving more than 4,100 people, EPA estimated violation
and trigger rates using SDWIS/FED because the Six-Year Review 2 data
(USEPA 2010e) for PWSs serving more than 4,100 people were not as
robust as the Six-Year Review 2 data (USEPA 2010e) for systems serving
4,100 or fewer people. EPA did not quantify changes in violation or
trigger rates for systems serving more than 4,100 people among the
current TCR, AIP, and Alternative options because of: (1) Limited Six-
Year Review 2 data (USEPA 2010e) to characterize these systems, (2) the
essentially unchanged monitoring requirements across options for these
systems, and (3) the level of effort already occurring to implement the
TCR.

D. Baseline Profiles

    The estimate of baseline conditions that EPA developed provides a
reference point for understanding net impacts of the proposed rule
revisions.
    Compliance with the GWR begins in December 2009, and the expected
compliance date of the RTCR is approximately five years following
commencement of the GWR implementation. The majority of PWSs are GWSs
and these systems are expected to be affected by the GWR. Because GWR
implementation prior to the effective date of RTCR is expected to cause
changes to GWSs, the baseline conditions that EPA developed for GWSs
account for the expected effects of the GWR.
    For PWSs serving more than 4,100 people, EPA assumed that present
conditions, as reflected in 2005 SDWIS/FED data, are an appropriate
representation of the conditions that are likely to exist when the RTCR
becomes effective. EPA assumed that a steady state exists at the
national level.
    The number of GW PWSs that disinfect is expected to change during
implementation of the GWR before the expected rule compliance date of
the proposed RTCR. Exhibit VI-4 shows the estimated baseline number of
the GW PWSs at the proposed RTCR compliance date.
[GRAPHIC] [TIFF OMITTED] TP14JY10.002

    EPA estimated the numbers of GW PWSs that monitor monthly,
quarterly, and annually under the current TCR based on an analysis of
the Six-Year Review 2 data (USEPA 2010e) and individual State statutes
conducted by EPA and the advisory committee Technical Work Group (TWG).
Of the GW PWSs serving 1,000 or fewer people, EPA estimated that
approximately 34,000 monitor monthly, 67,000 monitor quarterly, and
27,000 monitor annually. EPA assumed that the numbers of systems on
monthly, quarterly, and annual monitoring remain unchanged at the rule
effective date for either a continuation of the current TCR or for the
AIP option. Under the Alternative option, all PWSs, regardless of size
or type, start at monthly monitoring at the rule effective date.
    The following two tables provide an overview of summary statistics
relating to baseline water quality. Exhibit VI-5 shows the percentage
of total coliform- and E. coli-positive samples based on PWS type and
size. The percentages of samples that are total coliform-positive are
generally higher in ground water

systems than in surface water systems; in smaller systems than in
larger systems; and in NCWSs than in CWSs.
BILLING CODE 6560-50-P
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BILLING CODE 6560-50-C

    Exhibit VI-6 presents the number of acute and non-acute violations
received by PWSs. The number of violations is also an indicator of
baseline water quality prior to implementation of the proposed RTCR. As
discussed in detail in chapter 5 of the Proposed RTCR EA (USEPA 2010a),
EPA used these data to estimate the numbers of MCL violations and
triggers for PWSs serving more than 4,100 people for the three options.
Under the current TCR, larger systems incur a relatively small number
of violations annually, while smaller systems incur the majority.

                                     Exhibit VI-6--Baseline Number of TCR Violations by System Size and Type (2005)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              GW PWSs                                SW PWSs
                                                              ------------------------------------------------------------------------------   All PWSs
                                                                Non-acute      Acute        Total      Non-acute      Acute        Total        total
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          CWSs
--------------------------------------------------------------------------------------------------------------------------------------------------------
<= 100.......................................................          905           52          957           16            3           19          976
101-500......................................................          809           34          843           50            7           57          900
501-1,000....................................................          203           13          216           16            3           19          235
1,001-3,300..................................................          272            8          280           55            7           62          342
3,301-10,000.................................................          171            8          179           75            3           78          257
10,001-50,000................................................          125            8          133           78            4           82          215
50,001-100,000...............................................           11            2           13            5            4            9           22
100,001-1 Million............................................            1            1            2            3            1            4            6
> 1 Million..................................................  ...........  ...........  ...........            1  ...........            1            1
                                                              ------------------------------------------------------------------------------------------
    Totals...................................................        2,497          126        2,623          299           32          331        2,954
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         NTNCWSs
--------------------------------------------------------------------------------------------------------------------------------------------------------
<= 100.......................................................          514           34          548            7            2            9          557
101-500......................................................          346           20          366            4  ...........            4          370
501-1,000....................................................           57            6           63            2  ...........            2           65
1,001-3,300..................................................           58            4           62  ...........  ...........  ...........           62