expects that the LT2ESWTR provisions will prevent increases in
microbial risk resulting from the Stage 2 DBPR.

I. Effects of the Contaminant on the General Population and Groups
Within the General Population That Are Identified As Likely To Be at
Greater Risk of Adverse Health Effects

    EPA's Office of Water has historically considered risks to
sensitive subpopulations (including fetuses, infants, and children)
when establishing drinking water assessments, advisories and other
guidance, and standards (USEPA 1989) (56 FR 3526, January 30, 1991)
(USEPA 1991). In the case of Stage 2 DBPR, maximizing health protection
for sensitive subpopulations requires balancing risks to achieve the
recognized benefits of controlling waterborne pathogens while
minimizing risk of potential DBP toxicity. Experience shows that
waterborne disease from pathogens in drinking water is a major concern
for children and other subgroups (e.g., the elderly, immunocompromised,
and pregnant women) because of their greater vulnerabilities (Gerba et
al. 1996). EPA believes DBPs may also potentially pose risks to fetuses
and pregnant women (USEPA 1998a). In addition, because the elderly
population (age 65 and above) is naturally at a higher risk of
developing bladder cancer, their health risks may further increase as a
result of long-term DBP exposure (National Cancer Institute 2002).
    In developing this rule, risks to sensitive subpopulations,
including children, were taken into account in the assessments of
disinfectants and DBPs. More details on sensitive subpopulations can be
found in the Economic Analysis (USEPA 2005a). For each of the DBPs
included in the Stage 2 DBPR, the maximum contaminant level goals
(MCLG) are derived using the most sensitive endpoint among all
available data and an intraspecies uncertainty factor of 10 which
accounts for human variability including sensitive subpopulations, like
children. The Agency has evaluated several alternative regulatory
options and selected the one that balances cost with significant
benefits, including those for sensitive subpopulations. The Stage 2
DBPR will result in a potential reduction in cancer risk and a
potential reduction in reproductive and developmental risk to fetuses
and pregnant women. It should be noted that the LT2ESWTR, which
accompanies this rule, reduces pathogens in drinking water and further
protects sensitive subpopulations. See Section VII.G for a discussion
of EPA's requirements under Executive Order 13045.

J. Uncertainties in the Risk, Benefit, and Cost Estimates for the Stage
2 DBPR

    For today's final rule, EPA has estimated the current baseline risk
from exposure to DBPs in drinking water and projected the risk
reduction and cost for various rule alternatives. There is uncertainty
in the risk calculation, the benefit estimates, the cost estimates, and
the interaction with other regulations. The EA has an extensive
discussion of relevant uncertainties (USEPA 2005a). This section
briefly summarizes the major uncertainties. Table VI.J-1 presents a
summary of uncertainty in the cost and benefit estimates, refers to the
section or appendix of the EA where the information is introduced, and
estimates the potential effects that each may have on national cost and
benefit estimates.
    EPA believes that uncertainty in the compliance forecast has a
potentially large influence on cost and benefit estimates for today's
rule. Thus, the Agency has attempted to quantify the uncertainty by
giving equal weight to two different compliance forecast approaches.
One compliance forecast approach is based on the SWAT predictions, and
the other is based on the ``ICR Matrix Method.'' The ICR Matrix Method
uses the same basic approach as SWAT, but uses TTHM and HAA5 data from
the ICR directly to estimate the percent of plants changing technology
to comply with the Stage 2 DBPR and the resulting DBP reduction. To
characterize the uncertainty of the compliance forecast results, EPA
assumes a uniform distribution between SWAT and ICR Matrix Method
results (USEPA 2005a). That is, the cost and benefit estimates
presented in the preamble represent the midpoint between costs and
benefits estimated using the SWAT model, and those estimated using the
ICR Matrix Method. Cost estimates using the SWAT model are about 25%
lower than the midpoint estimates, while those using the ICR Matrix
Method are about 25% higher. Benefits estimated using the SWAT model
are about 30% lower than the midpoint estimates, while those using the
ICR Matrix Method are about 30% higher.
    EPA believes the compliance forecast may be overstated because the
technology decision tree does not consider low-cost, non-treatment
system improvements that could be used to comply with the Stage 2 DBPR.
These improvements, including things like flushing more frequently and
managing storage facilities to reduce water age, could be used by
systems to reduce TTHM and HAA5 levels for specific

locations in their distribution system to meet Stage 2 DBPR MCLs. Thus,
the standard compliance forecast method as developed during the M/DBP
FACA (with a 20 percent safety margin) is a reasonable estimation.
However, SWAT does not explicitly consider the IDSE. To address
uncertainty in the impact of the IDSE on the compliance forecast, EPA
revised the compliance forecast methodology, assigning equal
probability to 20 and 25 percent operational safety margins. EPA
believes the 25 percent safety margin is a reasonable high-end estimate
of system response to account for the influences of the IDSE. EPA used
a spatial variability analysis to determine the appropriate safety
margin to use to estimate the impact of the IDSE on the compliance
forecast.
    These alternative approaches for the compliance forecast estimate
are used to represent a range of possible results and are incorporated
into the cost and benefit models using Monte Carlo probability
functions. EPA believes this approach helps inform the reader of the
likely magnitude of the impact of the uncertainties.
    In addition to quantifying some uncertainties in the compliance
forecasts, EPA has explicitly accounted for uncertainty in estimated
treatment technology costs. Treatment costs are modeled using a
triangular distribution of  30 percent for Capital, and
 15 percent for O&M costs to recognize that the assumptions
for cost analysis to produce the national average are uncertain.
    For the cost estimates, uncertainty also exists in baseline data
inputs, such as the total number of disinfecting plants and their
typical average and design flow rates. Other cost model inputs such as
labor rates and laboratory fees also contain uncertainties. In these
cases, EPA has evaluated available data and estimated a cost input
value to represent the average of all water systems nationally. EPA
recognizes that there is uncertainty in this average and variability in
the characteristics of individual systems. The influence of these
uncertainties on national cost estimates is expected to be fairly
minor.
    For the benefits estimates, uncertainty exists in model inputs such
as the estimated PAR values and the cessation lag models. EPA
considered three approaches to estimate attributable risk: (1) a range
of risk derived from individual studies, (2) a risk estimate from a
meta-analysis, and (3) a risk estimate from a pooled analysis. To
quantify uncertainty in cessation lag, three independent cessation lag
models derived from three different epidemiological studies are used.
Also, two functional forms are used for each of these data sets and
uncertainty in the parameters of those functions is included in the
analysis. As noted previously, causality has not been established
between DBP levels and cancer endpoints, so the lower bound of
potential risk reductions may be as low as zero.
    In a number of different contexts over the past few years, the
Agency has considered the relative merits and assumptions encountered
when employing meta-analyses. Cessation lag modeling is a relatively
recent analysis that the Agency has incorporated into its risk analyses
to more appropriately model the timing of health benefits. The specific
papers upon which the Stage 2 analysis is based have been peer
reviewed. However, the Agency believes that it is time to consider
these Agency-wide science issues in a broader sense with outside
experts to better inform the Agency's future analyses.
    For monetization of benefits, EPA uses two alternatives for valuing
non-fatal bladder cancer. Other uncertainties, such as the linear
relationship between DBP reductions and reductions in bladder cancer
cases avoided, are discussed qualitatively.
    In addition to the uncertainties quantified as part of the benefits
evaluation, other uncertainties that have not been quantified could
result in either an over-or under-estimation of the benefits. Two of
the greatest uncertainties affecting the benefits of the Stage 2 DBPR,
benefits from potential reductions of cancers other than bladder and
benefits from possible reductions in potential reproductive and
developmental health effects, are unquantified. Both of these factors
could result in an underestimation of quantified Stage 2 DBPR benefits.

                                              Table VI.J-1.--Effects of Uncertainties on National Estimates
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                 Section with            Potential effect on benefit estimate                  Potential effect on cost estimates
 Assumptions for which there    full discussion --------------------------------------------------------------------------------------------------------
        is uncertainty          of uncertainty    Under-estimate     Over-estimate    Unknown impact    Under-estimate   Over-estimate    Unknown impact
--------------------------------------------------------------------------------------------------------------------------------------------------------
Uncertainty in the industry    3.4.............  ................  ................  X...............  ...............  ...............  X
 baseline (SDWIS and 1995
 CWSS data).
Uncertainty in observed data   3.7.............  ................  ................  X...............  ...............  ...............  X
 and predictive tools used to
 characterize DBP occurrence
 for the pre-Stage 1 baseline.
Uncertainty in predictive      Chapter 5,         Quantified in primary analysis (addresses potential
 tools used to develop the      Appendix A.                  underestimate or overestimate)
 compliance forecast for
 surface water systems (SWAT
 and ICR Matrix Method).
                                Quantified in primary analysis (addresses potential
                                           underestimate or overestimate)
Uncertainty in ground water    Chapter 5, A and  ................  ................  X...............  ...............  ...............  X
 compliance forecast            B.
 methodologies.
Operational safety margin of   5.2.............  ................  ................  X...............  ...............  ...............  X
 20%.
Impacts of the IDSE on the     5.3.............      Quantified in the primary analysis (addresses
 compliance forecast for the                                    potential underestimate)
 Preferred Regulatory
 Alternative.
                                   Quantified in the primary analysis (addresses
                                              potential underestimate)

Uncertainty in the PAR value.  6.1.1 Appendix E   Quantified in the primary analysis (addresses range
                                                    of potential effects, but true values could lie
                                                                     outside range)
Reduction in TTHM and HAA5     6.3.3...........  ................  ................  X...............
 used as proxies for all
 chlorination DBPs.
DBPs have a linear no-         6.2.1...........  ................  X...............
 threshold dose-response
 relationship for bladder
 cancer effects.
Uncertainty in benefits        6.5.2...........      Quantified in the primary analysis (addresses
 valuation inputs.                                      potential underestimate or overestimate)
Benefits of reduced cancers    6.7.............     Quantified in a sensitivity analysis (addresses
 other than bladder cancer                                      potential underestimate)
 are not included in the
 quantitative analysis.
Value of potential             6.8.............  X...............
 reproductive and
 developmental health effects
 avoided is not quantified in
 the primary analysis.
Treatment costs do not         7.4.1...........  ................  ................  ................  X..............
 include costs for minor
 operational changes
 predicted by SWAT.
Median operational and water   7.4.1...........  ................  ................  ................  ...............  ...............  X
 quality parameters
 considered for technology
 unit costs.
Economies of scale for         7.4.1...........  ................  ................  ................  ...............  X..............
 combination treatment
 technologies not considered.
Possible UV-chloramine         7.4.1...........  ................  ................  ................  ...............  X..............
 synergy not taken into
 account.
Potential low-cost             7.4.2...........  ................  ................  ................  ...............  X..............
 alternatives to treatment
 not considered.
Uncertainties in unit costs..  7.4.3...........  ................  ................  ................      Quantified in primary analysis (addresses
                                                                                potential overestimate or underestimate)
--------------------------------------------------------------------------------------------------------------------------------------------------------

K. Benefit/Cost Determination for the Stage 2 DBPR

    The Agency has determined that the benefits of the Stage 2 DBPR
justify the costs. As discussed previously, the main concern for the
Agency and the Advisory Committee involved in the Stage 2 rulemaking
process was to provide more equitable protection from DBPs across the
entire distribution system and reduce high DBP levels. The final rule
achieves this objective using the least cost alternative by targeting
sampling locations with high DBP levels and modifying how the annual
average DBP level is calculated. This will reduce both average DBP
levels associated with bladder cancer (and possibly other cancers) and
peak DBP levels which are potentially associated with reproductive and
developmental effects. In addition, this rule may reduce uncertainty
about drinking water quality and may allow some systems to avoid
installing additional technology to meet future drinking water
regulations.
    Table VI.K-1 presents net benefits for the four regulatory
alternatives evaluated by EPA. This table shows that net benefits are
positive for all four regulatory alternatives. Generally, analysis of
net benefits is used to identify alternatives where benefits exceed
costs, as well as the alternative that maximizes net benefits. However,
analyses of net benefits should consider both quantified and non-
quantified (where possible) benefits and costs. As discussed previously
with incremental net benefits, the usefulness of this analysis in
evaluating regulatory alternatives for the Stage 2 DBPR is somewhat
limited because many benefits from this rule are non-quantified and
non-monetized.
    Table VI.K-1 shows that the Preferred Alternative is the least cost
alternative. The Preferred Alternative has higher mean net benefits
than Alternative 1. Alternatives 2 and 3 have higher benefits than the
Preferred Alternative but also much greater costs. These regulatory
alternatives do not have the risk-targeted design of the Preferred
Alternative. Rather, a large number of systems would be required to
make treatment technology changes to meet the stringent standards under
these regulatory alternatives. Also, because causality has not been
established between DBP exposure and bladder cancer, actual benefits
may be as low as zero. EPA is promulgating the preferred regulatory
alternative because the Agency believes that such a drastic shift in
the nation's drinking water practices is not warranted at this time.

                      Table VI.K-1.--Mean Net Benefits by Regulatory Alternative ($Million)
----------------------------------------------------------------------------------------------------------------
                                            WTP for non-fatal       Mean annual     Mean annual      Mean net
           Rule alternative               bladder cancer cases         costs         benefits        benefits
----------------------------------------------------------------------------------------------------------------
                                        3 Percent Discount Rate, 25 Years
----------------------------------------------------------------------------------------------------------------
Preferred.............................  Lymphoma................           $78.8        $1,530.8          $1,452
A1....................................  ........................           254.1         1,376.6           1,122
A2....................................  ........................           421.7         5,167.4           4,746
A3....................................  ........................           634.2         7,129.6           6,495
Preferred.............................  Bronchitis..............            78.8           762.8             684
A1....................................  ........................           254.1           685.9             432
A2....................................  ........................           421.7         2,574.6           2,153
A3....................................  ........................           634.2         3,552.2           2,918
---------------------------------------
                                        7 Percent Discount Rate, 25 Years
----------------------------------------------------------------------------------------------------------------
Preferred.............................  Lymphoma................           $76.8        $1,246.5          $1,170
A1....................................  ........................           241.8         1,126.4             885
A2....................................  ........................           406.4         4,227.2           3,821
A3....................................  ........................           613.1         5,832.4           5,219
Preferred.............................  Bronchitis..............            76.8           620.7             544
A1....................................  ........................           241.8           560.8             319
A2....................................  ........................           406.4         2,104.6           1,698
A3....................................  ........................           613.1         2,903.8          2,291
----------------------------------------------------------------------------------------------------------------
Notes: Estimates are discounted to 2003 and given in 2003 dollars. Based on TTHM as an indicator, Villanueva et
  al. (2003) for baseline risk, and smoking/lung cancer cessation lag model. Assumes 26 percent of cases are
  fatal, 74 percent are non-fatal (USEPA 1999b). EPA recognizes that benefits may be as low as zero since
  causality has not yet been established exposure to chlorinated water and bladder cancer.

 Source: Exhibits 9.10 and 9.11, USEPA 2005a.

    The Agency also compared the costs and benefits for each regulatory
alternative by calculating which option is the most cost-effective. The
cost-effectiveness analysis compares the cost of the rule per bladder
cancer case avoided. This cost-effectiveness measure is another way of
examining the benefits and costs of the rule, but should not be used to
compare alternatives because an alternative with the lowest cost per
illness/death avoided may not result in the highest net benefits. Table
VI.K-2 shows the cost of the rule per case avoided. This table shows
that cost per case avoided for the preferred alternative seems
favorable when compared to the willingness to pay estimates. Additional
information about this analysis and other methods of comparing benefits
and costs can be found in the EA (USEPA 2005a).

 Table VI.K-2.--Estimated Cost Per Discounted Cased Avoided \1\ for the
  Regulatory Alternatives, Using TTHM as DBP Indicator and Smoking/Lung
              Cancer Cessation Lag Model ($Millions, 2003)
------------------------------------------------------------------------
                                                Cost per case avoided
             Rule alternative              -----------------------------
                                                  3%             7%
------------------------------------------------------------------------
Preferred.................................          $.033          $.041
Alternative 1.............................          1.18           1.42
Alternative 2.............................          0.52           0.63
Alternative 3.............................          0.57           0.69
------------------------------------------------------------------------
\1\ The cost effectiveness ratios are a potentially a high estimate
  because regulatory costs in the numerator are not adjusted by
  subtracting the avoided medical costs associated with cases avoided to
  produce a net cost numerator. Subtraction of theses costs would not be
  expected to alter the ranking of alternatives. In the case where
  thresholds of maximum public expenditure per case avoided are
  prescribed, defining the numerator more precisely by making such
  adjustments would be appropriate.

 Notes: In reference to conducting incremental CEA, OMB states that
  analyst should make sure that ``When constructing and comparing
  incremental cost-effectiveness ratios, [analysts] should make sure
  that inferior alternatives identified by the principles of strong and
  weak dominance are eliminated from consideration'' (OMB Circular A-4,
  p. 10). Alternative 1 is dominated by the Preferred Alternative and is
  therefore not included in the incremental analysis. The reason for
  this domination is mainly that the Preferred Alternative includes IDSE
  and Alternative 1 does not; and to a lesser degree because the bromate
  control included in Alternative 1 increases the costs but the benefits
  of this control are not quantified at this time. Alternative 2 is
  compared directly to the Preferred Alternative (skipping Alternative
  1) in this analysis. Cost per case avoided is in year 2003 dollars
  ($Millions), discounted for the 25 year analysis period to year 2005.

 Source: Exhibit 9.14, USEPA, 2005a.

L. Summary of Major Comments

    EPA received significant public comment on the analysis of benefits
and costs of the proposed Stage 2 DBPR in the following areas:
interpretation of health effects studies, derivation of benefits, use
of SWAT, illustrative example, unanticipated risk issues, and valuation
of cancer cases avoided. The following discussion summarizes public
comment in these areas and EPA's responses.
1. Interpretation of Health Effects Studies
    EPA requested comment on the conclusions of the cancer health
effects section and the epidemiology and toxicology studies discussed.
A number of comments questioned the overall

interpretation of the studies presented by EPA. A few comments pointed
out missed studies. Commenters also asked about concordance between
cancer epidemiology and toxicology. Some commenters also felt EPA did
not discuss the broad range of risks from DBPs other than the ones
regulated.
    The Agency continues to believe that, although there is not a
causal link, the cancer literature points to an association between
bladder cancer and potentially rectal and colon cancer and exposure to
chlorinated surface water. EPA has included in today's preamble the
literature that commenters pointed out as missing and expands on its
discussion of non-regulated DBPs.
    EPA believes that a lack of bladder cancer effect in toxicological
studies does not negate the findings in epidemiological studies at this
time. Tumor site concordance between human and test animal is not
necessary to determine carcinogenic potential. While there is evidence
from human cancer epidemiology studies that lifetime consumption of the
DBP mixture within chlorinated surface water poses a bladder cancer
risk, the specific causative constituents have not been identified. EPA
will continue to evaluate new mode-of-action data as it becomes
available.
    Several comments were received on EPA's characterization of the
literature on reproductive and developmental health risk. Some
commenters wanted EPA to characterize reproductive and developmental
health effects more strongly, stating that current research shows more
evidence for these effects than described in the proposed preamble.
Others thought that EPA's characterization in the proposal was too
strong, and that EPA had overemphasized these health concerns. Some
commenters noted that certain published studies were missing from EPA's
risk discussion.
    EPA believes that the characterization of reproductive and
developmental risks in the final Stage 2 DBPR preamble is appropriate
based on the weight of evidence evaluation of the reproductive and
developmental epidemiology database described in Section III.C. EPA
considered comments and incorporated additional and recent studies into
its characterization of health risks in today's final preamble. While
no causal link has been established, EPA's evaluation of the available
studies continues to indicate a potential health hazard that warrants
additional regulatory action beyond the Stage 1 DBPR. The
inconsistencies and uncertainties remaining in the available science
support the incremental nature of change in today's rule.
    EPA did not include all findings from every study in the proposed
DBPR preamble because the intent was to provide a summary overview and
more importantly, the Agency's conclusions regarding the weight of
evidence. The epidemiology literature has inconsistencies in its
findings on the relationship between various reproductive and
developmental health effects and DBPs. In this final preamble, EPA
describes how recent studies since the proposal further inform the
perspective of overall risk from exposure to DBPs. EPA continues to
believe that studies indicate a potential hazard.
2. Derivation of Benefits
    EPA received numerous comments on the derivation of benefits from
occurrence estimates for the Stage 2 DBPR. The majority of the comments
provided addressed EPA's use of a cessation lag model to estimate the
timing of benefits and a PAR analysis to estimate reduced risks.
Several commenters opposed the cessation lag model proposed by EPA,
suggesting that EPA use a longer cessation lag period or conduct a
sensitivity analysis on the cessation lag exponent.
    In the effort to develop a cessation lag model specific to DBPs,
EPA reviewed the available epidemiological literature for information
relating to the timing of exposure and response, but could not identify
any studies that could, alone or in combination, support a specific
cessation lag model for DBPs in drinking water. Thus, in keeping with
the SAB recommendation to consider other models in the absence of
specific cessation lag information (USEPA 2001d), EPA explored the use
of information on other carcinogens that could be used to characterize
the influence of cessation lag in calculating benefits. The benefit
analysis for today's rule uses three cessation lag models, which allows
for a better characterization of uncertainty than did the approach used
in the proposal. More details on this analysis are in the EA (USEPA
2005a).
    Additional comments were received on the use of PAR values derived
from epidemiology studies to determine the number of bladder cancer
cases attributable to DBP exposure. Some commenters remarked that there
was not sufficient evidence in the epidemiology studies used to develop
a reliable PAR estimate. A key issue expressed in the comments was that
studies that developed the PAR estimates did not adequately control for
confounders. One commenter supported EPA review of the Villanueva
(2003) meta-analysis, stating that this was the best available data on
the issue.
    EPA revised the methodology for calculating PAR values for bladder
cancer associated with exposure to chlorinated drinking water by
considering three different analytical approaches as described in
Section V.B.2. EPA used the PAR values from all three approaches to
estimate the number of bladder cancer cases ultimately avoided annually
as a result of the Stage 2 DBPR. Taken together, the three approaches
provide a reasonable estimate of the range of potential risk. For
simplicity, EPA used the Villanueva et al. (2003) study to calculate
the annual benefits of the rule. The benefit estimates derived from
Villanueva et al. (2003) capture a substantial portion of the overall
range of results, reflecting the uncertainty in both the underlying OR
and PAR values, as well as the uncertainty in DBP reductions for Stage
2. More details on the PAR analysis can be found in the EA (USEPA
2005a).
3. Use of SWAT
    Comments received on the use of SWAT for the compliance forecast
claimed that the model probably underestimates DBP occurrence levels
and hence underestimates compliance costs. Other commenters supported
EPA's occurrence estimation methods and results. Some commenters added
that monitoring under the IDSE will produce different results than
monitoring for the ICR and that SWAT did not capture these changes.
    EPA describes in detail the limitations of SWAT as well as all
assumptions and uncertainties associated with the model in the EA
published with today's rule. EPA believes that, for the reasons stated
below, the standard compliance forecast method using SWAT, as developed
during the M-DBP FACA, provides a reasonable prediction of national
treatment changes and resulting DBP levels anticipated for the Stage 2
DBPR:
    1. SWAT predictive equations for TTHM and HAA5 were calibrated to
ICR-observed TTHM and HAA5 data.
    2. SWAT estimates are based on 12 months of influent water quality
data, treatment train information, and related characteristics for the
273 ICR surface water plants. EPA believes the ICR data provide a
robust basis for the compliance forecast as it represents significant
variability with respect to factors influencing DBP formation,
including temperature, residence time, and geographical region.
    3. EPA uses a ``delta'' approach to reduce the impact of
uncertainty in

SWAT's predictive equations for TTHM and HAA5. Under this approach, EPA
1) estimates the difference in technology and TTHM and HAA5
concentration predictions between pre-Stage 1 and post-Stage 1; 2)
estimates the difference in technology and TTHM and HAA5 concentration
predictions between pre-Stage 1 and post-Stage 2; and 3) subtracts the
result of the first estimate from the second estimate to predict the
impacts between Stage 1 and Stage 2. Since each predictive estimate has
bias in the same direction, EPA believes that this methodology
minimized overall predictive error.
    In response to commenters concerns about potential uncertainties in
the SWAT predictions, EPA also developed the ``ICR Matrix Method.'' The
ICR Matrix Method uses TTHM and HAA5 data from the ICR to estimate the
percent of plants changing technology to comply with the Stage 2 DBPR
and the resulting DBP reduction. The EA includes a detailed description
of the ICR Matrix Method (USEPA 2005a). In the analysis for today's
rule, EPA gives equal weight to SWAT and ICR Matrix Method predictions
in estimating Stage 2 compliance forecasts and resultant reductions in
DBP exposure. The ICR Matrix Method is also used to estimate reductions
in the occurrence of peak TTHM and HAA5 concentrations because SWAT-
predicted TTHM and HAA5 concentrations are valid only when considering
national averages, not at the plant level.
    EPA revised the Stage 2 DBPR compliance forecast methodology to
quantify the potential impacts of the IDSE for large and medium surface
water systems. For these systems, EPA predicted compliance implications
using a safety margin of both 20 and 25 percent based on an analysis of
spatial variability in TTHM and HAA5 occurrence. EPA assigned equal
probability to the 20 and 25 percent safety margins because both
alternatives are considered equally plausible. These changes result in
a wider uncertainty range for the compliance cost estimates than under
the EA of the proposed rule. EPA assumes the 20 percent operational
safety margin accounts for variability in small surface water systems
and all ground water systems. Small systems are not expected to find
significantly higher levels that affect their compliance as a result of
the IDSE because their distribution systems are not as complex as large
systems. Additionally, the IDSE is not expected to significantly impact
the compliance forecast for ground water systems because they have more
consistent source water quality and do not experience significant year-
to-year variability in TTHM and HAA5 occurrence.
    As some commenters noted, any underestimation in costs as a result
of the compliance forecast is associated with an underestimation in the
benefits. Accordingly, EPA adjusted both cost and benefits estimates
based on the ICR Matrix Method and the impact of the IDSE for the upper
end of the compliance forecast range.
4. Illustrative Example
    Many comments were received on the illustrative calculation of
fetal loss benefits included in the proposed EA. Many commenters
recommended that EPA remove this calculation because of uncertainties
in the underlying data. Other commenters, however, expressed support
for this calculation because of the magnitude of potential benefits,
and suggested that EPA include these benefits in its primary analysis.
    EPA believes that the reproductive and developmental epidemiologic
data, although not conclusive, are suggestive of potential health
effects in humans exposed to DBPs. EPA does not believe the available
evidence provides an adequate basis for quantifying potential
reproductive and developmental risks. Nevertheless, given the
widespread nature of exposure to DBPs, the importance our society
places on reproductive and developmental health, and the large number
of fetal losses experienced each year in the U.S. (nearly 1 million),
the Agency believes that it is appropriate to provide some quantitative
indication of the potential risk suggested by some of the published
results on reproductive and developmental endpoints, despite the
absence of certainty regarding a causal link between disinfection
byproducts and these risks and the inconsistencies between studies.
However, the Agency is unable at this time to either develop a specific
estimate of the value of avoiding fetal loss or to use a benefit
transfer methodology to estimate the value from studies that address
other endpoints.
5. Unanticipated Risk Issues
    Comments were received that expressed concern about unanticipated
risks that could result from the proposed Stage 2 DBPR. Several
commenters remarked that regulation of TTHM and HAA5 would not control
levels of other DBPs that may be more toxic than these indicator
compounds, such as NDMA. Some commenters supported future research on
the potential health effects of other DBPs. Other comments suggested
that EPA further consider these risks when developing the final Stage 2
DBPR.
    EPA has addressed the occurrence of other DBPs in Section VI.H of
this document and in the EA (USEPA 2005a). Levels of some DBPs may
increase because of treatment changes anticipated as a result of
today's rule. However, these DBPs generally occur at much lower levels
than TTHM and HAA5, often more than an order of magnitude less (USEPA
2005f, Weinberg et al. 2002). For NDMA, studies have shown formation in
both chlorinated and chloraminated systems (Barrett et al. 2003). The
uncertainties surrounding NDMA formation make determinations regarding
the impact of the Stage 2 DBPR difficult. In addition, other routes of
exposure appear to be more significant than drinking water. Dietary
sources of NDMA include preserved meat and fish products, beer and
tobacco. EPA is looking at calculating the relative source contribution
of these routes of exposure compared to drinking water.
    EPA continues to support the use of TTHM and HAA5 as indicators for
DBP regulation. The presence of TTHM and HAA5 is representative of the
occurrence of many other chlorination DBPs; thus, a reduction in the
TTHM and HAA5 generally indicates an overall reduction of DBPs. EPA
also supports additional research on unregulated and unknown DBPs to
ensure continual public health protection.
6. Valuation of Cancer Cases Avoided
    A number of commenters remarked on the valuation of cancer cases
avoided. Some commenters supported the use of value of statistical life
(VSL) analysis in monetizing the benefits of fatal bladder cancer cases
avoided. Comments were also received in support of the addition of
expected medical costs for treating fatal bladder cancer cases to the
VSL estimates. Other commenters recommended that EPA further review the
use of willingness-to-pay estimates used to value the non-fatal cancer
cases avoided. These comments stated concern over the similarity of
bronchitis and lymphoma to bladder cancer and the resulting limitation
of benefits transfer.
    EPA thanks commenters for expressing support of the use of VSL and
valuation of fatal bladder cancer cases. EPA acknowledges that the
willingness to pay (WTP) to avoid curable lymphoma or chronic
bronchitis is not a perfect substitute for the WTP to avoid a case of
non-fatal bladder cancer. However, non-fatal internal cancers,
regardless of type, generally present patients with very similar

treatment, health, and long-term quality of life implications,
including surgery, radiation or chemotherapy treatments (with attendant
side effects), and generally diminished vitality over the duration of
the illness. In the absence of more specific WTP studies, EPA believes
the WTP values for avoiding a case of curable lymphoma or a case of
chronic bronchitis provides a reasonable, though not definitive,
substitute for the value of avoiding non-fatal bladder cancer.

VII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866, [58 FR 51735, (October 4, 1993)] the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order. The Order defines ``significant regulatory action'' as
one that is likely to result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or Tribal governments or
communities;
    (2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof; or
    (4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
    Pursuant to the terms of Executive Order 12866, it has been
determined that this rule is a ``significant regulatory action.'' As
such, this action was submitted to OMB for review. Changes made in
response to OMB suggestions or recommendations will be documented in
the public record.

B. Paperwork Reduction Act

    The Office of Management and Budget (OMB) has approved the
information collection requirements contained in this rule under the
provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and
has assigned OMB control number 2040-0265 (USEPA 2005n).
    The information collected as a result of this rule will allow the
States and EPA to determine appropriate requirements for specific
systems, and to evaluate compliance with the rule. For the first three
years after Stage 2 DBPR promulgation, the major information
requirements involve monitoring activities, which include conducting
the IDSE and submission of the IDSE report, and tracking compliance.
The information collection requirements are mandatory (Part 141), and
the information collected is not confidential.
    The estimate of annual average burden hours for the Stage 2 DBPR
for systems and States is 228,529 hours. This estimate covers the first
three years of the Stage 2 DBPR and most of the IDSE (small system
reports are not due until the fourth year). The annual average
aggregate cost estimate is $9.8 million for operation and maintenance
as a purchase of service for lab work and $6.6 million is associated
with labor. The annual burden hour per response is 4.18 hours. The
frequency of response (average responses per respondent) is 7.59
annually. The estimated number of likely respondents is 7,202 per year
(the product of burden hours per response, frequency, and respondents
does not total the annual average burden hours due to rounding).
Because disinfecting systems have already purchased basic monitoring
equipment to comply with the Stage 1 DBPR, EPA assumes no capital
start-up costs are associated with the Stage 2 DBPR ICR.
    Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of information;
and transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required
to respond to a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations in 40 CFR are listed in 40 CFR part 9. In addition, EPA is
amending the table in 40 CFR part 9 of currently approved OMB control
numbers for various regulations to list the regulatory citations for
the information requirements contained in this final rule.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency
to prepare a regulatory flexibility analysis for any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
    The RFA provides default definitions for each type of small entity.
Small entities are defined as: (1) A small business as defined by the
Small Business Administrations's (SBA) regulations at 13 CFR 121.201;
(2) a small governmental jurisdiction that is a government of a city,
county, town, school district or special district with a population of
less than 50,000; and (3) a small organization that is any ``not-for-
profit enterprise which is independently owned and operated and is not
dominant in its field.'' However, the RFA also authorizes an agency to
use alternative definitions for each category of small entity, ``which
are appropriate to the activities of the agency'' after proposing the
alternative definition(s) in the Federal Register and taking comment. 5
U.S.C. 601(3)-(5). In addition, to establish an alternative small
business definition, agencies must consult with SBA's Chief Council for
Advocacy.
    For purposes of assessing the impacts of today's rule on small
entities, EPA considered small entities to be public water systems
serving 10,000 or fewer persons. As required by the RFA, EPA proposed
using this alternative definition in the Federal Register (63 FR 7620,
February 13, 1998), requested public comment, consulted with the Small
Business Administration (SBA), and finalized the alternative definition
in the Consumer Confidence Reports regulation (63 FR 44511, August 19,
1998). As stated in that Final Rule, the alternative definition is
applied to this regulation as well.
    After considering the economic impacts of today's final rule on
small entities, I certify that this action will not have a significant
economic impact on a substantial number of small entities. The small
entities regulated by this final rule are PWSs serving fewer than
10,000 people. We have determined that 92 small surface water and
ground water under the direct influence of surface water (GWUDI)
systems (or 2.16% of all

small surface water and GWUDI systems affected by the Stage 2 DBPR)
will experience an impact of 1% or greater of average annual revenues.
Of the 92, 40 small surface water and GWUDI systems (or 0.94% of all
small surface water and GWUDI systems affected by the Stage 2 DBPR)
will experience an impact of 3% or greater of average annual revenues.
Further, 354 small ground water systems (or 1.02% of all small ground
water systems affected by the Stage 2 DBPR) will experience an impact
of 1% or greater of average annual revenues. Of the 354, 45 small
ground water systems (or 0.13% of all small ground water systems
affected by the Stage 2 DBPR) will experience an impact of 3% or
greater of average annual revenues.
    Although this final rule will not have a significant economic
impact on a substantial number of small entities, EPA nonetheless has
tried to reduce the impact of this rule on small entities. The Stage 2
DBPR contains a number of provisions to minimize the impact of the rule
on systems generally, and on small systems in particular. For example,
small systems have a longer time frame to comply with requirements than
large systems (see Sec.  141.600(c) and Sec.  141.620(c)). The final
rule determines monitoring frequency based on population rather than
plant-based monitoring requirements (see Sec.  141.605 and Sec.
141.621(a)) as proposed. Small systems will also have to take fewer
samples than large systems due to the 40/30 waiver (see Sec.
141.603(a)), for which small, ground water systems are expected to be
able to qualify, and the very small system waiver (see Sec.  141.604).
    Funding may be available from programs administered by EPA and
other Federal agencies to assist small PWSs in complying with the Stage
2 DBPR. The Drinking Water State Revolving Fund (DWSRF) assists PWSs
with financing the costs of infrastructure needed to achieve or
maintain compliance with SDWA requirements. Through the DWSRF, EPA
awards capitalization grants to States, which in turn can provide low-
cost loans and other types of assistance to eligible PWSs. Loans made
under the program can have interest rates between 0 percent and market
rate and repayment terms of up to 20 years. States prioritize funding
based on projects that address the most serious risks to human health
and assist PWSs most in need. Congress provided the DWSRF program $8
billion for fiscal years 1997 through 2004.
    The DWSRF places an emphasis on small and disadvantaged
communities. States must provide a minimum of 15% of the available
funds for loans to small communities. A State has the option of
providing up to 30% of the grant awarded to the State to furnish
additional assistance to State-defined disadvantaged communities. This
assistance can take the form of lower interest rates, principal
forgiveness, or negative interest rate loans. The State may also extend
repayment terms of loans for disadvantaged communities to up to 30
years. A State can set aside up to 2% of the grant to provide technical
assistance to PWSs serving communities with populations fewer than
10,000.
    In addition to the DWSRF, money is available from the Department of
Agriculture's Rural Utility Service (RUS) and Housing and Urban
Development's Community Development Block Grant (CDBG) program. RUS
provides loans, guaranteed loans, and grants to improve, repair, or
construct water supply and distribution systems in rural areas and
towns of up to 10,000 people. In fiscal year 2003, RUS had over $1.5
billion of available funds for water and environmental programs. The
CDBG program includes direct grants to States, which in turn are
awarded to smaller communities, rural areas, and colo[ntilde]as in
Arizona, California, New Mexico, and Texas and direct grants to U.S.
territories and trusts. The CDBG budget for fiscal year 2003 totaled
over $4.4 billion.
    Although not required by the RFA to convene a Small Business
Advocacy Review (SBAR) Panel because EPA determined that the proposed
rule would not have a significant economic impact on a substantial
number of small entities, EPA did convene a panel to obtain advice and
recommendations from representatives of the small entities potentially
subject to this rule's requirements. For a description of the SBAR
Panel and stakeholder recommendations, please see the proposed rule
(USEPA 2003a).

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and Tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``Federal mandates'' that
may result in expenditures to State, local and Tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
one year. Before promulgating an EPA rule for which a written statement
is needed, section 205 of the UMRA generally requires EPA to identify
and consider a reasonable number of regulatory alternatives and adopt
the least costly, most cost-effective or least burdensome alternative
that achieves the objectives of the rule. The provisions of section 205
do not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including Tribal governments, it must have developed under
section 203 of the UMRA a small government agency plan. The plan must
provide for notifying potentially affected small governments, enabling
officials of affected small governments to have meaningful and timely
input in the development of EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory
requirements.
    EPA has determined that this rule may contain a Federal mandate
that results in expenditures of $100 million or more for the State,
Local, and Tribal governments, in the aggregate in the private sector
in any one year. While the annualized costs fall below the $100 million
threshold, the costs in some future years may be above the $100 million
mark as public drinking water systems make capital investments and
finance these through bonds, loans, and other means. EPA's year by year
cost tables do not reflect that investments through bonds, loans, and
other means spread out these costs over many years. The cost analysis
in general does not consider that some systems may be eligible for
financial assistance such as low-interest loans and grants through such
programs as the Drinking Water State Revolving Fund.
    As noted earlier, today's final rule is promulgated pursuant to
section 1412 (b)(1)(A) of the Safe Drinking Water Act (SDWA), as
amended in 1996, which directs EPA to promulgate a national primary
drinking water regulation for a contaminant if EPA determines that the
contaminant may have an adverse effect on the health of persons, occurs
in PWSs with a frequency and at levels of public health concern, and
regulation presents a meaningful opportunity for health risk reduction.

    Section VI of this preamble discusses the cost and benefits
associated with the Stage 2 DBPR. Details are presented in the Economic
Analysis (USEPA 2005a).

     Table VII.D-1--Public and Private Costs for the Stage 2 DBPR (Annualized at 3 and 7 Percent, $Millions)
----------------------------------------------------------------------------------------------------------------
                                                                              Percent of 3%      Percent of 7%
                                       3% discount rate   7% discount rate  grand total costs  grand total costs
                                                                                (percent)          (percent)
----------------------------------------------------------------------------------------------------------------
Surface Water Systems Costs.........              $41.4              $41.2                 53                 54
Ground Water Systems Costs..........               20.3               19.2                 26                 25
State Costs.........................                1.7                1.7                  2                  2
Tribal Costs........................                0.4                0.4                  1                  0
    Total Public....................               63.8               62.5                 81                 81
Surface Water Systems Costs.........                6.4                6.3                  8                  8
Ground Water Systems Costs..........                8.5                8.0                 11                 10
    Total Private...................               15.0               14.3                 19                 19
        Grand total.................               78.8               76.8                100               100
----------------------------------------------------------------------------------------------------------------
Note: Detail may not add due to independent rounding. Estimates are discounted to 2003 and given in 2003
  dollars.

 Source: Exhibits 3.2 and 7.5, USEPA 2005a.

    To meet the UMRA requirement in section 202, EPA analyzed future
compliance costs and possible disproportionate budgetary effects. The
Agency believes that the cost estimates and regulatory alternatives
indicated earlier and discussed in more detail in section VI of this
preamble, accurately characterize future compliance costs of today's
rule.
    In analyzing disproportionate impacts, EPA considered the impact on
(1) different regions of the United States, (2) State, local, and
Tribal governments, (3) urban, rural and other types of communities,
and (4) any segment of the private sector. This analysis is presented
in Chapter 7of the Economic Analysis (USEPA 2005a). EPA analyzed four
regulatory alternatives and selected the least costly of these in
accordance with UMRA Section 205.
    EPA has determined that the Stage 2 DBPR contains no regulatory
requirements that might significantly or uniquely affect small
governments. The Stage 2 DBPR affects all size systems. As described in
section VII.C, EPA has certified that today's rule will not have a
significant economic impact on a substantial number of small entities.
Average annual expenditures for small CWSs to comply with the Stage 2
DBPR range from $27.7 to $26.1 million at a 3 and 7 percent discount
rate, respectively.
    Consistent with the intergovernmental consultation provisions of
section 204 of the UMRA and Executive Order 12875, ``Enhancing the
Intergovernmental Partnership,'' EPA has already initiated
consultations with the governmental entities affected by this rule. The
consultations are described in the proposed rule (68 FR 49654, August
18, 2003).

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' is defined in the
Executive Order to include regulations that have ``substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.''
    This final rule does not have federalism implications. It will not
have substantial direct effects on the States, on the relationship
between national government and the States, or on the distribution of
power and responsibilities among various levels of government, as
specified in Executive Order 13132. The final rule has one-time costs
for implementation of approximately $7.8 million. Thus, Executive Order
13132 does not apply to this rule.
    Although section 6 of Executive Order 13132 does not apply to this
rule, in the spirit of Executive Order 13132, and consistent with EPA
policy to promote communications between EPA and State and local
governments, EPA nonetheless specifically solicited comment on the
proposed rule from State and local officials and did consult with State
and local officials in developing this rule. A description of that
consultation can be found in the preamble to the proposed rule, 68 FR
49548, (August 18, 2003).

F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

    Executive Order 13175, entitled ``Consultation and Coordination
with Indian Tribal Governments'' (65 FR 67249, November 9, 2000),
requires EPA to develop ``an accountable process to ensure meaningful
and timely input by tribal officials in the development of regulatory
policies that have tribal implications.'' Under Executive Order 13175,
EPA may not issue a regulation that has Tribal implications, that
imposes substantial direct compliance costs, and that is not required
by statute, unless the Federal government provides the funds necessary
to pay the direct compliance costs incurred by Tribal governments, or
EPA consults with Tribal officials early in the process of developing
the proposed regulation and develops a Tribal summary impact statement.
    EPA has concluded that this final rule may have Tribal
implications, because it may impose substantial direct compliance costs
on Tribal governments, and the Federal government will not provide the
funds necessary to pay those costs.
    Accordingly, EPA provides the following Tribal summary impact
statement as required by section 5(b). EPA provides further detail on
Tribal impact in the Economic Analysis (USEPA 2005a). Total Tribal
costs are estimated to be approximately $391,773 per year (at a 3
percent discount rate) and this cost is distributed across 755 Tribal
systems. The cost for individual systems depend on system size and
source water type. Of the 755 Tribes that may be affected in some form
by the Stage 2 DBPR, 654 use ground water as a source and 101 systems
use surface water or GWUDI. Since the majority of Tribal systems are
ground water systems

serving fewer than 500 people, approximately 15.6 percent of all Tribal
systems will have to conduct an IDSE. As a result, the Stage 2 DBPR is
most likely to have an impact on Tribes using surface water or GWUDI
serving more than 500 people.
    EPA consulted with Tribal officials early in the process of
developing this regulation to permit them to have meaningful and timely
input into its development. Moreover, in the spirit of Executive Order
13175, and consistent with EPA policy to promote communications between
EPA and Tribal governments, EPA specifically solicited comment on the
proposed rule from Tribal officials.
    As required by section 7(a), EPA's Tribal Consultation Official has
certified that the requirements of the Executive Order has been met in
a meaningful and timely manner. A copy of this certification has been
included in the docket for this rule.

G. Executive order 13045: Protection of Children From Environmental
Health Risks and Safety Risks

    Executive Order 13045: ``Protection of Children from Environmental
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies
to any rule that: (1) is determined to be ``economically significant''
as defined under 12866, and; (2) concerns an environmental health or
safety risk that EPA has reason to believe may have a disproportionate
effect on children. If the regulatory action meets both criteria, the
Agency must evaluate the environmental health or safety effects of the
planned rule on children, and explain why the planned regulation is
preferable to other potentially effective and reasonably feasible
alternatives considered by the Agency.
    While this final rule is not subject to the Executive Order because
it is not economically significant as defined in Executive Order 12866,
EPA nonetheless has reason to believe that the environmental health or
safety risk (i.e., the risk associated with DBPs) addressed by this
action may have a disproportionate effect on children. EPA believes
that the Stage 2 DBPR will result in greater risk reduction for
children than for the general population. The results of the
assessments are contained in Section VI.I of this preamble and in the
Economic Analysis (USEPA 2005a). A copy of all documents has been
placed in the public docket for this action.

H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use

    This rule is not a ``significant energy action'' as defined in
Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR
28355, May 22, 2001) because it is not likely to have a significant
adverse effect on the supply, distribution, or use of energy. This
determination is based on the following analysis.
    The first consideration is whether the Stage 2 DBPR would adversely
affect the supply of energy. The Stage 2 DBPR does not regulate power
generation, either directly or indirectly. The public and private
utilities that the Stage 2 DBPR regulates do not, as a rule, generate
power. Further, the cost increases borne by customers of water
utilities as a result of the Stage 2 DBPR are a low percentage of the
total cost of water, except for a very few small systems that might
install advanced technologies that must spread that cost over a narrow
customer base. Therefore, the customers that are power generation
utilities are unlikely to face any significant effects as a result of
the Stage 2 DBPR. In sum, the Stage 2 DBPR does not regulate the supply
of energy, does not generally regulate the utilities that supply
energy, and is unlikely significantly to affect the customer base of
energy suppliers. Thus, the Stage 2 DBPR would not translate into
adverse effects on the supply of energy.
    The second consideration is whether the Stage 2 DBPR would
adversely affect the distribution of energy. The Stage 2 DBPR does not
regulate any aspect of energy distribution. The utilities that are
regulated by the Stage 2 DBPR already have electrical service. As
derived later in this section, the final rule is projected to increase
peak electricity demand at water utilities by only 0.009 percent.
Therefore, EPA estimates that the existing connections are adequate and
that the Stage 2 DBPR has no discernable adverse effect on energy
distribution.
    The third consideration is whether the Stage 2 DBPR would adversely
affect the use of energy. Because some drinking water utilities are
expected to add treatment technologies that use electrical power, this
potential impact is evaluated in more detail. The analyses that
underlay the estimation of costs for the Stage 2 DBPR are national in
scope and do not identify specific plants or utilities that may install
treatment in response to the rule. As a result, no analysis of the
effect on specific energy suppliers is possible with the available
data. The approach used to estimate the impact of energy use,
therefore, focuses on national-level impacts. The analysis estimates
the additional energy use due to the Stage 2 DBPR and compares that
analysis to the national levels of power generation in terms of average
and peak loads.
    The first step in the analysis is to estimate the energy used by
the technologies expected to be installed as a result of the Stage 2
DBPR. Energy use is not directly stated in Technologies and Costs for
the Final Long Term 2 Enhanced Surface Water Treatment Rule and Final
Stage 2 Disinfectants and Disinfection Byproducts Rule (USEPA 2005g),
but the annual cost of energy for each technology addition or upgrade
necessitated by the Stage 2 DBPR is provided. An estimate of plant-
level energy use is derived by dividing the total energy cost per plant
for a range of flows by an average national cost of electricity of
$0.076/ kilowatt hours per year (kWh/yr) (USDOE 2004a). These
calculations are shown in detail in the Economic Analysis (USEPA
2005a). The energy use per plant for each flow range and technology is
then multiplied by the number of plants predicted to install each
technology in a given flow range. The energy requirements for each flow
range are then added to produce a national total. No electricity use is
subtracted to account for the technologies that may be replaced by new
technologies, resulting in a conservative estimate of the increase in
energy use. The incremental national annual energy usage is 0.12
million megawatt-hours (MWh).
    According to the U.S. Department of Energy's Information
Administration, electricity producers generated 3,848 million MWh of
electricity in 2003 (USDOE 2004b). Therefore, even using the highest
assumed energy use for the Stage 2 DBPR, the rule when fully
implemented would result in only a 0.003 percent increase in annual
average energy use.
    In addition to average energy use, the impact at times of peak
power demand is important. To examine whether increased energy usage
might significantly affect the capacity margins of energy suppliers,
their peak season generating capacity reserve was compared to an
estimate of peak incremental power demand by water utilities.
    Both energy use and water use peak in the summer months, so the
most significant effects on supply would be seen then. In the summer of
2003, U.S. generation capacity exceeded consumption by 15 percent, or

approximately 160,000 MW (USDOE 2004b). Assuming around-the-clock
operation of water treatment plants, the total energy requirement can
be divided by 8,760 hours per year to obtain an average power demand of
13.28 MW. A more detailed derivation of this value is shown in the
Economic Analysis (USEPA 2005a). Assuming that power demand is
proportional to water flow through the plant and that peak flow can be
as high as twice the average daily flow during the summer months, about
26.55 MW could be needed for treatment technologies installed to comply
with the Stage 2 DBPR. This is only 0.017 percent of the capacity
margin available at peak use.
    Although EPA recognizes that not all areas have a 15 percent
capacity margin and that this margin varies across regions and through
time, this analysis reflects the effect of the rule on national energy
supply, distribution, and use. While certain areas, notably California,
have experienced shortfalls in generating capacity in the recent past,
a peak incremental power requirement of 26.55 MW nationwide is not
likely to significantly change the energy supply, distribution, or use
in any given area. Considering this analysis, EPA has concluded that
Stage 2 DBPR will not have any significant effect on the use of energy,
based on annual average use and on conditions of peak power demand.

I. National Technology Transfer and Advancement Act

    As noted in the proposed rule, Section 12(d) of the National
Technology Transfer and Advancement Act of 1995 (``NTTAA''), Public Law
104-113, section 12(d) (15 U.S.C. 272 note) directs EPA to use
voluntary consensus standards in its regulatory activities unless to do
so would be inconsistent with applicable law or otherwise impractical.
Voluntary consensus standards are technical standards (e.g., materials
specifications, test methods, sampling procedures, and business
practices) that are developed or adopted by voluntary consensus
standard bodies. The NTTAA directs EPA to provide Congress, through
OMB, explanations when the Agency decides not to use available and
applicable voluntary consensus standards.
    This rulemaking involves technical standards. EPA has decided to
use two voluntary consensus methods for HAA5 (Standard Method 6251 B,
1998 in the 20th Edition of Standard Methods for the Examination of
Water and Wastewater and Standard Method 6251 B-94, 1994 available at
http://www.standardmethods.org). In addition to these two consensus

methods, EPA is also approving EPA Method 552.3 for HAA5, which also
can be used to measure three unregulated HAAs that are not included in
the consensus methods. The unregulated HAAs are included in the EPA
method because some water systems monitor for them in order to better
understand their treatment processes and provide greater public health
protection. EPA is approving two voluntary consensus standards for
daily monitoring for chlorite (Standard Method 4500-ClO2 E,
1998, in the 20th Edition of Standard Methods for the Examination of
Water and Wastewater and Standard Method 4500-ClO2 E-00,
2000, available at http://www.standardmethods.org). EPA Method 327.0,

Revision 1.1 is also being approved for daily monitoring for both
chlorite and chlorine dioxide in order to provide an alternative to the
titration procedure that is required in the Standard Methods. EPA is
approving a method from American Society for Testing and Materials
International for bromate, chlorite and bromide analyses (ASTM D 6581-
00, 2000, ASTM International. Annual Book of ASTM Standards, Volume
11.01, American Society for Testing and Materials International, 2001
or any year containing the cited version of the method may be used).
EPA is also approving three EPA methods (EPA Methods 317.0 Revision
2.0, 321.8, and 326.0) that provide greater sensitivity and selectivity
for bromate than the ASTM consensus standard. These EPA methods are
required in order to provide better process control for water systems
using ozone in the treatment process and to allow for a reduced
monitoring option. EPA Methods 317.0 Revision 2.0 and 326.0 can also be
used to determine chlorite and bromide. Today's action approves eight
voluntary consensus standards for determining free, combined, and total
chlorine (SM 4500-Cl D, SM 4500-Cl F, and 4500-Cl G, 1998, in the 20th
Edition of Standard Methods for the Examination of Water and Wastewater
and SM 4500-Cl D-00, SM 4500-Cl F-00, and 4500-Cl G-00, 2000 available
at http://www.standardmethods.org and ASTM D 1253-86(96), 1996, ASTM

International, Annual Book of ASTM Standards, Volume 11.01, American
Society for Testing and Materials International, 1996 or any year
containing the cited version of the method may be used and ASTM D 1253-
03, 2003, ASTM International, Annual Book of ASTM Standards, Volume
11.01, American Society for Testing and Materials International, 2004
or any year containing the cited version of the method may be used).
EPA is approving four standards for determining total chlorine (SM
4500-Cl E and SM 4500-Cl I, 1998, in the 20th Edition of Standard
Methods for the Examination of Water and Wastewater and SM 4500-Cl E-00
and SM 4500-Cl I-00, 2000 available at http://www.standardmethods.org).

Two standards for determining free chlorine are approved in today's
rule (SM 4500-Cl H, 1998, in the 20th Edition of Standard Methods for
the Examination of Water and Wastewater and SM 4500-Cl H-00, 2000
available at http://www.standardmethods.org). Today's action approves

three voluntary consensus standards for measuring chlorine dioxide
(4500-ClO2 D and 4500-ClO2 E, 1998, in the 20th
Edition of Standard Methods for the Examination of Water and Wastewater
and 4500-ClO2 E-00, 2000 available at http://www.standardmethods.org
). EPA is approving six standards for

determining TOC and DOC (SM 5310 B, SM 5310 C, and SM 5310 D, 1998, in
the 20th Edition of Standard Methods for the Examination of Water and
Wastewater and SM 5310 B-00, SM 5310 C-00, and SM 5310 D-00, 2000
available at http://www.standardmethods.org). Two standards for

determining UV254 are approved in today's rule (SM 5910 B,
1998, in the 20th Edition of Standard Methods for the Examination of
Water and Wastewater and SM 5910 B-00, 2000 available at http://www.standardmethods.org
). EPA is also approving EPA Method 415.3

Revision 1.1 for the determination of TOC and SUVA (DOC and
UV254). This EPA method contains method performance data
that are not available in the consensus standards.
    Copies of the ASTM standards may be obtained from the American
Society for Testing and Materials International, 100 Barr Harbor Drive,
West Conshohocken, PA 19428-2959. The Standard Methods may be obtained
from the American Public Health Association, 1015 Fifteenth Street,
NW., Washington, DC 20005.

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations or Low-Income Populations

    Executive Order 12898 establishes a Federal policy for
incorporating environmental justice into Federal agency missions by
directing agencies to identify and address disproportionately high and
adverse human health or environmental effects of its programs,
policies, and activities on minority and low-income populations. EPA
has

considered environmental justice related issues concerning the
potential impacts of this action and consulted with minority and low-
income stakeholders. A description of this consultation can be found in
the proposed rule (USEPA 2003a).

K. Consultations With the Science Advisory Board, National Drinking
Water Advisory Council, and the Secretary of Health and Human Services

    In accordance with Section 1412(d) and (e) of the SDWA, the Agency
consulted with the Science Advisory Board, the National Drinking Water
Advisory Council (NDWAC), and the Secretary of Health and Human
Services on today's rule.
    EPA met with the SAB to discuss the Stage 2 DBPR on June 13, 2001
(Washington, DC), September 25-26, 2001 (teleconference), and December
10-12, 2001 (Los Angeles, CA). Written comments from the December 2001
meeting of the SAB addressing the occurrence analysis and risk
assessment were generally supportive. SAB comments are discussed in
greater detail within the proposal.
    EPA met with the NDWAC on November 8, 2001, in Washington, DC to
discuss the Stage 2 DBPR proposal. The Advisory Committee generally
supported the need for the Stage 2 DBPR based on health and occurrence
data, but also stressed the importance of providing flexibility to the
systems implementing the rule. The results of these discussions are
included in the docket for the proposed rule.

L. Plain Language

    Executive Order 12866 requires each agency to write its rules in
plain language. Readable regulations help the public find requirements
quickly and understand them easily. They increase compliance,
strengthen enforcement, and decrease mistakes, frustration, phone
calls, appeals, and distrust of government. EPA made every effort to
write this preamble to the final rule in as clear, concise, and
unambiguous manner as possible.

M. Analysis of the Likely Effect of Compliance With the Stage 2 DBPR on
the Technical, Managerial, and Financial Capacity of Public Water
Systems

    Section 1420(d)(3) of SDWA, as amended, requires that, in
promulgating a National Primary Drinking Water Regulation (NPDWR), the
Administrator shall include an analysis of the likely effect of
compliance with the regulation on the technical, managerial, and
financial (TMF) capacity of PWSs. This analysis is described in more
detail and can be found in the Economic Analysis (USEPA 2005a).
Analyses reflect only the impact of new or revised requirements, as
established by the LT2ESWTR; the impacts of previously established
requirements on system capacity are not considered.
    EPA has defined overall water system capacity as the ability to
plan for, achieve, and maintain compliance with applicable drinking
water standards. Capacity encompasses three components: technical,
managerial, and financial. Technical capacity is the physical and
operational ability of a water system to meet SDWA requirements. This
refers to the physical infrastructure of the water system, including
the adequacy of source water and the adequacy of treatment, storage,
and distribution infrastructure. It also refers to the ability of
system personnel to adequately operate and maintain the system and to
otherwise implement requisite technical knowledge. Managerial capacity
is the ability of a water system to conduct its affairs to achieve and
maintain compliance with SDWA requirements. Managerial capacity refers
to the system's institutional and administrative capabilities.
Financial capacity is a water system's ability to acquire and manage
sufficient financial resources to allow the system to achieve and
maintain compliance with SDWA requirements.
    EPA estimated the impact of the Stage 2 DBPR on small and large
system capacity as a result of the measures that systems are expected
to adopt to meet the requirements of the rule (e.g., selecting
monitoring sites for the IDSE, installing/upgrading treatment, operator
training, communication with regulators and the service community,
etc.). The Stage 2 DBPR may have a substantial impact on the capacity
of the 1,743 plants in small systems and 518 plants in large systems
that must make changes to their treatment process to meet the Stage 2
DBPR requirements. However, while the impact to these systems is
potentially significant, only 3.8 percent of all plants regulated under
the Stage 2 DBPR (2,261 of 60,220) will be affected by this
requirement. Since individual systems may employ more than one plant,
it is likely that fewer than 1,620 systems (3.4 percent of 48,293
systems) will be affected by this requirement. The new IDSE and
monitoring requirements are expected to have a small impact on the
technical and managerial capacity of small systems, a moderate impact
on the financial capacity of some small systems, and a much smaller
impact on large systems. The capacity of systems that must conduct an
operational evaluation will only be impacted in a minor way, while
those systems that must only familiarize themselves with the rule (the
large majority of systems) will not face any capacity impact as a
result of the Stage 2 DBPR.

N. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. A Major rule cannot
take effect until 60 days after it is published in the Federal
Register. This action is a ``major rule'' as defined by 5 U.S.C.
804(2). This rule will be effective March 6, 2006.

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List of Subjects

40 CFR Part 9

    Reporting and recordkeeping requirements.

40 CFR Part 141

    Environmental protection, Chemicals, Indians-lands, Incorporation
by reference, Intergovernmental relations, Radiation protection,
Reporting and recordkeeping requirements, Water supply.

40 CFR Part 142

    Environmental protection, Administrative practice and procedure,
Chemicals, Indians-lands, Radiation protection, Reporting and
recordkeeping requirements, Water supply.

    Dated: December 15, 2005.
Stephen L. Johnson,
Administrator.

0
For the reasons set forth in the preamble, title 40 chapter I of the
Code of Federal Regulations is amended as follows:

PART 9--OMB APPROVALS UNDER THE PAPERWORK REDUCTION ACT

0
1. The authority citation for part 9 continues to read as follows:

    Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003,
2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33
U.S.C. 1251 et seq., 1311, 1313d, 1314, 1318, 1321, 1326, 1330,
1342, 1344, 1345 (d) and (e), 1361; Executive Order 11735, 38 FR
21243, 3 CFR, 1971-1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246,
300f, 300g, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1,
300j-2, 300j-3, 300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-
7671q, 7542, 9601-9657, 11023, 11048.

0
2. In Sec.  9.1 the table is amended as follows:
0
a. Under the heading ``National Primary Drinking Water Regulations
Implementation'' by adding entries in numerical order for ``Sec.
141.600-141.605, 141.620-141.626, 141.629''.
0
b. Under the heading ``National Primary Drinking Water Regulations
Implementation'' by removing entries ``Sec.  142.14(a),142.14(a)-
(d)(3)'' and adding entries in numerical order for ``142.14(a) (1)-(7),
142.14(a)(8), 142.14(b)-(d) and 142.16(m)'' as follows:

Sec.  9.1  OMB approvals under the Paperwork Reduction Act.

* * * * *

------------------------------------------------------------------------
                                                            OMB control
                     40 CFR citation                            No.
------------------------------------------------------------------------

                                * * * * *
---------------------------------------------------------
               National Primary Drinking Water Regulations
------------------------------------------------------------------------

                                * * * * *
141.600-141.605.........................................       2040-0265
141.620-141.626.........................................       2040-0265
141.629.................................................       2040-0265
---------------------------------------------------------
       National Primary Drinking Water Regulations Implementation
------------------------------------------------------------------------

                                * * * * *
142.14(a)(1)-(7)........................................       2040-0265
142.14(a)(8)............................................       2040-0265
142.14(b)-(d)...........................................       2040-0090

                                * * * * *
142.16(m)...............................................       2040-0265
------------------------------------------------------------------------

* * * * *

PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS

0
3. The authority citation for part 141 continues to read as follows:

    Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9, and 300j-11.

0
4. Section 141.2 is amended by adding, in alphabetical order,
definitions for ``Combined distribution system'', ``Consecutive
system'', ``Dual sample sets'', ``Finished water'', ``GAC20'',
``Locational running annual average'', and ``Wholesale system'' and
revising the definition of ``GAC10'' to read as follows:

Sec.  141.2  Definitions.

* * * * *
    Combined distribution system is the interconnected distribution
system consisting of the distribution systems of wholesale systems and
of the consecutive systems that receive finished water.
* * * * *
    Consecutive system is a public water system that receives some or
all of its finished water from one or more wholesale systems. Delivery
may be through a direct connection or through the distribution system
of one or more consecutive systems.
* * * * *
    Dual sample set is a set of two samples collected at the same time
and same location, with one sample analyzed for TTHM and the other

sample analyzed for HAA5. Dual sample sets are collected for the
purposes of conducting an IDSE under subpart U of this part and
determining compliance with the TTHM and HAA5 MCLs under subpart V of
this part.
* * * * *
    Finished water is water that is introduced into the distribution
system of a public water system and is intended for distribution and
consumption without further treatment, except as treatment necessary to
maintain water quality in the distribution system (e.g., booster
disinfection, addition of corrosion control chemicals).
* * * * *
    GAC10 means granular activated carbon filter beds with an empty-bed
contact time of 10 minutes based on average daily flow and a carbon
reactivation frequency of every 180 days, except that the reactivation
frequency for GAC10 used as a best available technology for compliance
with subpart V MCLs under Sec.  141.64(b)(2) shall be 120 days.
    GAC20 means granular activated carbon filter beds with an empty-bed
contact time of 20 minutes based on average daily flow and a carbon
reactivation frequency of every 240 days.
* * * * *
    Locational running annual average (LRAA) is the average of sample
analytical results for samples taken at a particular monitoring
location during the previous four calendar quarters.
* * * * *
    Wholesale system is a public water system that treats source water
as necessary to produce finished water and then delivers some or all of
that finished water to another public water system. Delivery may be
through a direct connection or through the distribution system of one
or more consecutive systems.

Sec.  141.12  [Removed]

0
5. Section 141.12 is removed and reserved.

Sec.  141.30  [Removed]

0
6. Section 141.30 is removed.

Sec.  141.32  [Removed]

0
7. Section 141.32 is removed and reserved.

0
8. Section 141.33 is amended by revising the first sentence of
paragraph (a) introductory text and adding paragraph (f) to read as
follows:

Sec.  141.33  Record maintenance.

* * * * *
    (a) Records of microbiological analyses and turbidity analyses made
pursuant to this part shall be kept for not less than 5 years. * * *
* * * * *
    (f) Copies of monitoring plans developed pursuant to this part
shall be kept for the same period of time as the records of analyses
taken under the plan are required to be kept under paragraph (a) of
this section, except as specified elsewhere in this part.

0
9. Section 141.53 is amended by revising the table to read as follows:

Sec.  141.53  Maximum contaminant level goals for disinfection
byproducts.

* * * * *

------------------------------------------------------------------------
          Disinfection byproduct                     MCLG (mg/L)
------------------------------------------------------------------------
Bromodichloromethane......................  zero
Bromoform.................................  zero
Bromate...................................  zero
Chlorite..................................  0.8
Chloroform................................  0.07
Dibromochloromethane......................  0.06
Dichloroacetic acid.......................  zero
Monochloroacetic acid.....................  0.07
Trichloroacetic acid......................  0.02
------------------------------------------------------------------------

0
10. Section 141.64 is revised to read as follows:

Sec.  141.64  Maximum contaminant levels for disinfection byproducts.

    (a) Bromate and chlorite. The maximum contaminant levels (MCLs) for
bromate and chlorite are as follows:

------------------------------------------------------------------------
                   Disinfection byproduct                     MCL (mg/L)
------------------------------------------------------------------------
Bromate....................................................        0.010
Chlorite...................................................        1.0
------------------------------------------------------------------------

    (1) Compliance dates for CWSs and NTNCWSs. Subpart H systems
serving 10,000 or more persons must comply with this paragraph (a)
beginning January 1, 2002. Subpart H systems serving fewer than 10,000
persons and systems using only ground water not under the direct
influence of surface water must comply with this paragraph (a)
beginning January 1, 2004.
    (2) The Administrator, pursuant to section 1412 of the Act, hereby
identifies the following as the best technology, treatment techniques,
or other means available for achieving compliance with the maximum
contaminant levels for bromate and chlorite identified in this
paragraph (a):

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         Disinfection byproduct             Best available technology
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Bromate................................  Control of ozone treatment
                                          process to reduce production
                                          of bromate
Chlorite...............................  Control of treatment processes