The site-specific study must provide a description of the technologies,
operational measures, or sampling approaches or any combination of them
to be used to meet the BTA for impingement mortality. The study must
demonstrate that the system of technologies has been optimized to
minimize impingement mortality. EPA notes the ``system'' may consist of
one or more technologies already in place, or may be combined with
newly installed technologies. Further, the study must include a minimum
of two years of biological data collection, as just described.
    The EPA is aware that it is possible for a facility to reduce its
rate of impingement, but the same number of impinged fish die. This has
the unintended consequence of increasing the percent impingement
mortality calculated by the facility. EPA does not intend for such
facilities to be penalized for significant reductions in impingement
rates obtained through existing technologies and practices in place.
Therefore, one difference in the required study for the system of
technologies compliance alternative (as compared to the study required
for modified traveling screens) is an understanding that operational
measures, best management practices, intake location, and other
technologies do not always lend themselves to direct impingement
mortality measurements or data collection. Thus the study can include
flow measurements and monitoring the rate of impingement (as opposed to
directly monitoring mortality) as described below.
    If the facility chooses to rely on credit for reductions in the
rate of impingement already achieved, the impingement technology
performance optimization study must document the reductions to be used
as credit. The estimated reductions in impingement must be based on a
comparison of the facility to a once-through cooling system with a
traveling screen located on the shoreline of the source waterbody. For
example, a facility with an offshore intake, an intake canal, or an
intake located immediately downstream of a dam in a cold water stream,
could demonstrate the population of fish at the intake is lower in
these areas, resulting in lower rates of impingement. This provision is
intended to allow a facility that conducted or completed a baseline
characterization under the Phase II rule to use that same information
as part of their demonstration under this rule.
    As discussed in Section VI, EPA has identified flow reduction as
one of the best ways to reduce both impingement and entrainment.
Today's final rule, as part of the system of technologies compliance
option at Sec.  125.94(c)(6), provides the owner or operator of a
facility the opportunity to demonstrate flow reduction as part of
meeting the IM standards. If the facility chooses flow reduction to
reduce impingement, the study at Sec.  122.21(r)(6)(ii) must include
two years of intake flows measured daily. This flow information plus
the data collected under Sec.  122.21(r)(4)(iv) would be used to
document how the flow reduction results in a reduced rate of
impingement, as well as documenting the extent to which such reductions
are seasonal or intermittent. Many pumps operate at only one speed,
which doesn't allow the facility to adjust its intake flow to changing
conditions. As a potential application of Sec.  125.94(c)(6), EPA is
aware of a manufacturing facility that installed multiple pumps of
different sizes, and the operator only utilized those pumps that were
necessary to obtain the exact amount of cooling water needed. As
another example, variable speed drives offer many facilities an
opportunity to reduce their intake flows by as much as 10 percent.
Variable speed drives are available at all facilities, and EPA expects
variable speed drives will be considered when replacing existing
recirculating pumps; however, EPA also acknowledges variable speed
drives may not be practical in all cases. Nevertheless, EPA expects
variable speed drives will be considered by the Director when
establishing entrainment requirements under today's final rule. EPA
provided an example of how a facility would receive credit for existing
technologies in the NODA (see 77 FR 34322, June 11, 2011). An
additional sample calculation that includes flow reduction is provided
later in this section.
    The study must identify each of these contributing components, and
requires the calculation of the impingement mortality reflecting each
component of the system. The impingement technology performance
optimization study must demonstrate the system of technologies has been
optimized to minimize impingement mortality. In addition, the study
must document the percent impingement mortality

reflecting optimized operation of the total system of technologies,
operational measures, and best management practices at Sec.
122.21(r)(6)(ii)(D). The Director may then determine the system of
technologies is the best technology available for impingement reduction
at the site. The Director would then include permit conditions that
ensure the technology will perform as demonstrated.
6. Sec.  122.21(r)(7) Entrainment Performance Studies
    EPA proposed that a facility must submit all previously conducted
performance studies, but has revised this provision in the final rule
to include only entrainment related studies. Impingement performance
studies, where relevant, are already part of the permit application at
Sec.  122.21(r)(6). This avoids imposing a requirement on all
facilities to submit previous impingement studies that may be
unnecessary, and eliminates a burden on the Director to review all such
studies, many of which may no longer be relevant.\90\ Under today's
final rule, the applicant must submit a description of any biological
survival studies conducted at the facility and a summary of any
conclusions or results, including the following: site-specific studies
addressing technology efficacy, through-facility entrainment survival
(distinguished for eggs and larvae), entrainment analyses, or studies
conducted at other locations including a justification as to why the
data are relevant and representative of conditions at the facility.
Because of changes in the waterbody over time, studies older than 10
years must include an explanation of why the data are still relevant
and representative of conditions at the facility. If the data are no
longer relevant and representative, the Director may reject the data.
The Director uses such studies when establishing technology-based
requirements for entrainment. Permit applicants are not required to
conduct new studies simply to fulfill this requirement. This
requirement is rather aimed at obtaining results for relevant studies
that have already been conducted as part of past permit proceedings or
for other purposes even if those studies were not completed or
conducted entirely as planned.
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    \90\ For example, the study may be old and no longer
representative, the study may address a pilot study of a technology
no longer under consideration by the facility, or the facility may
have already selected one of the compliance methods for IM based on
pre-approved technologies at Sec.  125.94(c)(1), (2) or (4).
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7. Sec.  122.21(r)(8) Operational Status
    The applicant must submit a description of the operational status
of each unit for which a cooling water intake structure provides water
for cooling, including the following: Descriptions of each individual
unit's operating status including age of the unit, capacity utilization
for the previous five years (including any unusual or extended outages
that significantly affect the facility's reporting of flow,
impingement, or other data), and any major upgrades completed in the
past 15 years (e.g., boiler or condenser replacement, changes to fuel
type, a new production line); a description of completed, approved, or
scheduled uprates and NRC (Nuclear Regulatory Commission) relicensing
status for nuclear facilities; a description of plans or schedules for
decommissioning or replacement of units; and a description of current
and future production schedules for manufacturing facilities. The
Director will use such information in determining the BTA for
entrainment as well as when establishing compliance schedules. For
example, where the remaining useful plant life is considerably shorter
than the useful life of an entrainment technology or where a facility
has a planned retirement within the next permit cycle, this information
is useful to support a determination regarding that specific
entrainment technology. This information would also be used under Sec.
125.94(c)(12) to document infrequently used power generating units that
operate with a capacity utilization of less than 8 percent averaged
over a 24-month block contiguous period and that the Director may
therefore determine warrants IM controls less stringent than Sec.
125.94(c)(1) through (c)(7). With respect to entrainment, the BTA for
entrainment is determined by the Director for each site, and energy
reliability is one factor the Director may consider when establishing
entrainment controls (see Sec.  125.98(f)(3)). EPA expects the
information submitted on energy reliability will be considered by the
Director when making a BTA determination for entrainment for low CUR
units.
8. Sec.  122.21(r)(9) Entrainment Characterization Study
    Facilities that withdraw greater than 125 mgd AIF must develop a
study that includes a minimum of two years of entrainment data
collection. EPA envisions the facility would extend the data collection
methods and frequency to develop the source water characterization
already required by Sec.  122.21(r)(4) to develop the Entrainment
Characterization Study. The study would include complete documentation
of the data collection period and frequency of entrainment
characterization, and an identification of the organisms sampled to the
lowest taxon possible. The data collection must be representative of
the entrainment at each intake, and the study must document how the
location of the intake in the waterbody and the water column are
accounted for. The study must document the intake flows associated with
the data collection. Consistent with the permit application
requirements requiring biological data collection at Sec.  122.21(r)(4)
and (6), EPA requires at least two years of data to sufficiently
characterize annual, seasonal, and diel variations in entrainment,
including variations related to climate, weather, spawning, feeding,
and water column migration. Also consistent with the permit application
requirements at Sec.  122.21(r)(4) and (6), facilities may use
historical data that are representative of current operation of the
facility and conditions at the site with documentation regarding the
continued relevance of the data. The study must include analysis of the
data to determine total entrainment and entrainment mortality.
Documentation in the study must include the method in which latent
mortality would be identified, and all methods and quality assurance/
quality control procedures for sampling and data analysis would be
described. The sampling and data analysis methods must be appropriate
for a quantitative survey.
    This information will help the Director determine the site-specific
BTA for entrainment. For facilities with no entrainment technologies
currently in place, this information characterizes the total potential
for entrainment. The information can also be used to demonstrate that
technologies and other measures already in place, or site-specific
factors such as intake location or design, already reduce entrainment.
For example, abundance data might demonstrate lower comparative
densities that can significantly lower entrainment rates. The
information could also be used by new units under Sec.  125.94(e)(2) to
demonstrate that an alternative technology or combination of
technologies reduce entrainment at that site to a level commensurate
with closed-cycle cooling.

9. Sec.  122.21(r)(10) Comprehensive Technical Feasibility and Cost
Evaluation Study
    The owner or operator of the facility must submit an engineering
study of the technical feasibility and incremental costs of candidate
entrainment control technologies. The study must include an evaluation
of technical feasibility of closed-cycle cooling and fine-mesh screens
with a mesh size of 2 mm or smaller, reuse of water or alternate
sources of cooling water, and any other entrainment reduction
technologies identified by the applicant or requested by the Director.
This study must include a description of all technologies and
operational measures considered (which could include alternative
designs of closed-cycle recirculating systems such as natural draft
cooling towers, hybrid designs, compact or multi-cell arrangements, or
the conversion of helper towers to a fully recirculating system); and
documentation of factors that make a candidate technology impractical
or infeasible for further evaluation. For example, a discussion of land
availability might include an evaluation of adjacent land, and acres
potentially available because of generating unit retirements,
production unit retirements, other buildings and equipment retirements,
ponds, coal piles, rail yards, transmission yards, and parking lots;
decommissioning of existing units; repurposing of existing land uses;
documentation that insufficient acres are available on-site; and
evidence of the feasibility of the purchase or other acquisition of
property adjacent to the facility.
    For the analysis of water reuse and use of alternate sources of
cooling water, the owner or operator must examine the available
alternatives for reuse of effluent from within the facility or from
other dischargers in the vicinity. The volume of water available need
not be for the full intake flow; reuse of water could contribute to a
partial reduction in flow at the facility. Additionally, if the
facility were to retrofit to a closed-cycle system, the significant
reduction in flow may make nearby alternative sources more feasible.
This analysis should include an estimate of the cost to build any new
infrastructure (e.g., piping, pump houses) and the ongoing operational
costs (e.g., pump costs) for the Director's consideration.
    The final rule requires that the cost information be presented as
both the facility's compliance costs and the social costs, and in net
present value (NPV) terms and the corresponding annual value. Social
costs are the costs estimated from the viewpoint of society, rather
than individual stakeholders. Social cost represents the total burden
imposed on the economy; it is the sum of all opportunity costs
incurred. See Chapter 8 of EPA's 2010 Guidelines for Preparing Economic
Analyses (DCN 10-3258). Some adjustments to facility compliance costs
to produce social costs cause them to be higher than compliance costs,
while other cause social costs to be lower. Although a facility makes
investment decisions by taking tax consequences into account (after-tax
costs), the favorable tax treatment of investments is viewed as a
transfer and not a real resource cost, thus pre-tax costs are used in
social cost analysis. From society's viewpoint, costs in the future
must be amortized and discounted to net present value using a social
discount rate, rather than a market cost of capital as reflected in
market interest rates. The Office of Management and Budget (OMB)
Circular A-4 (DCN 10-3266) instructs agencies to use both 3 percent and
7 percent discount rates. Certain administrative costs are not borne by
a facility, but rather by the Director, and are social costs.
Compliance costs include the facility's administrative costs, including
costs of permit application, while the social cost adjustment includes
the Director's administrative costs. EPA has estimated the Directors'
administrative costs in the ICR for the final rule, and describes the
methodology for estimating these costs in detail in the EA. Facilities
may adopt a similar approach to including Director's administrative
costs in their social cost estimates. In addition, this component is
not expected to be large or to vary significantly across technology
options considered.
    From a facility's viewpoint, downtime costs include lost net
revenue, while from society's viewpoint, if another facility is
dispatched or inventory of manufactured goods can be sold, the only
social cost of downtime is any increase in marginal costs of production
at other facilities dispatched or the cost of holding inventory. Unless
a facility can demonstrate that its costs of compliance will result in
lower overall supply in the markets in which its products are sold, and
that the effect of the lowered supply is an increase in market price
and lower quantity of product sold, the facility should not make a
social cost adjustment to reflect these larger market impacts.
    In addition to the required social costs, the owner or operator may
choose to provide facility level compliance costs; however, such costs
must be provided and discussed separately from social costs. The cost
evaluation component of this study must include engineering cost
estimates of all technologies considered above and also discuss and
provide documentation of any outages, downtime, energy penalties or
other effects on revenue. The cost evaluation should be based on least-
cost approaches to implementing each candidate technology while meeting
all regulatory and operational requirements of the facility.
Depreciation schedules, interest rates, further consideration of
remaining useful life of the facility as discussed in Sec.
122.21(r)(8), and any related assumptions must be identified. The owner
or operator of the facility must obtain peer review of the
Comprehensive Technical Feasibility and Cost Evaluation Study, as
described in Section 12.
10. Sec.  122.21(r)(11) Benefits Valuation Study
    The owner or operator of the facility must submit a detailed
discussion of the benefits of the candidate entrainment reduction
technologies evaluated in Sec.  122.21(r)(10) and using data in the
Entrainment Characterization Study in Sec.  122.21(r)(9). Each category
of benefits should be described narratively, and when possible benefits
should be quantified in physical or biological units and monetized
using appropriate economic valuation methods. This includes incremental
changes in the impingement mortality and entrainment of individual fish
and shellfish for all exposed life stages, estimation of changes in
stock and harvest levels of commercial and recreational species, and
description of any monetization. This may include monetization using
market values, market proxies (e.g., models based on travel costs or
other methodologies), benefits transfer and stated preference methods.
Benefits that cannot be monetized should be quantified where feasible
and discussed qualitatively where not. The study must identify
increased or decreased thermal discharges, and must evaluate the
potential changes in facility capacity, operations, and reliability due
to relaxed permitting constraints related to thermal discharges. The
study must also include discussion of recent mitigation efforts already
completed and how these have affected fish abundance and ecosystem
viability in the intake structure's area of influence. Finally, the
study must identify other benefits to the environment and the
community, including improvements for mammals, birds, and other
organisms and aquatic habitats. The owner or operator of the facility
must obtain peer review of the benefits evaluation study, as described
in Section 12. EPA expects peer

reviewers to have appropriate qualifications (e.g., fisheries
biologist, economist) for the subject matter. The Director may consult
with EPA and Federal, State and Tribal fish and wildlife management
agencies with responsibility for fish and wildlife potentially affected
by the cooling water intake structure(s) to determine which peer review
comments must be addressed by the final study. The dollar values in the
social benefits analysis should be based on the principle of
willingness-to-pay (WTP), which captures monetary benefits by measuring
what individuals are willing to forgo in order to enjoy a particular
benefit. While the Director must consider benefit and cost information,
the Director will also determine if this information is of sufficient
rigor to make a decision on entrainment controls on the basis of this
information. For instance, the Director may decide not to rely on
benefit-cost information in establishing the entrainment controls when
the benefits analysis includes only a qualitative discussion of nonuse
benefits. Willingness-to-pay for nonuse benefits can be measured using
benefits transfer or a stated preference survey. However, the rule does
not require the Director to require a facility owner or operator to
conduct or submit a stated preference survey to assess benefits.
11. Sec.  122.21(r)(12) Non-Water Quality Environmental and Other
Impacts Assessment
    The owner or operator of the facility must submit a detailed
discussion of the changes in non-water quality environmental and other
factors attributed to technologies or operational measures, or both,
considered. These changes may include, for example, increases or
decreases in the following: Energy consumption; air pollutant emissions
and their health and environmental impacts; noise; safety concerns,
such as the potential for plumes, icing, and availability of emergency
cooling water; grid reliability, including an estimate of changes to
facility capacity, operations, and reliability due to cooling water
availability; consumptive water use (including effects of surface water
evaporation of thermal discharges); and facility reliability, such as
production of steam and impacts to production based on process unit
heating or cooling. The owner or operator of the facility must provide
for peer review of the Non-Water Quality Environmental and Other
Impacts Assessment as described in the following section.
12. Sec.  122.21(r)(13) Peer Review
    The owner or operator of the facility must provide for peer review
of the permit application studies required at Sec.  122.21(r)(10)
Comprehensive Technical Feasibility and Cost Evaluation Study, Sec.
122.21(r)(11) Benefits Valuation Study, and Sec.  122.21(r)(12) Non-
Water Quality and Other Impacts Assessment. While facilities that
withdraw more than 125 mgd AIF must conduct these studies and therefore
must provide for peer review, facilities that withdraw equal to or less
than 125 mgd AIF may have study requirements including peer review as
determined by the Director. In today's final rule, EPA did not adopt
separate peer review requirements for the Entrainment Characterization
Study at Sec.  122.21(r)(9), because this data would be included in the
Comprehensive Technical Feasibility and Cost Evaluation Study, Benefits
Valuation Study, and Non-Water Quality and Other Impacts Assessment,
and these studies are already subject to peer review. For these
reasons, EPA reduced the burden in the final rule by eliminating the
peer review requirement for entrainment characterization.
    EPA recognized at proposal that in many cases it is more efficient
for permit applicants to combine the required studies into one document
and have them reviewed holistically by a single set of peer reviewers.
Such an approach is allowed by the final rule, as long as the peer
review panel has the background appropriate to conduct a complete and
combined review and the Director approves.
    The Director may consult with Federal, State and Tribal fish and
wildlife management agencies with responsibility for fish and wildlife
potentially affected by the cooling water intake structure(s). Further,
the Director may require the owner or operator of the facility to
include additional peer reviewers of the studies. EPA expects peer
reviewers to have appropriate qualifications (e.g., in the fields of
biology, engineering) for the subject matter. An explanation for any
significant reviewer comments not accepted must be included in the
final study submission. Additional guidance on conducting peer review
is available on EPA's Peer Review Program Web site at www.epa.gov/peerreview.
13. Sec.  122.21(r)(14) New Units
    New units at existing facilities must identify the compliance
method for the new unit under the permit application requirements at
Sec.  122.21(r)(14). Where the facility complies with BTA standards for
entrainment at Sec.  125.94(e)(1) by reducing its intake flows
commensurate with that of a closed-cycle recirculating system (as
defined at Sec.  125.92(c)(1)), the BTA standards for impingement
mortality will have been met by Sec.  125.94(c)(1). To comply with the
alternative at Sec.  125.94(e)(2), there must be a demonstration that
entrainment reductions equivalent to 90 percent or greater of the
reductions that could be achieved through compliance with Sec.
125.94(e)(1).\91\ In this case, permit application requirement Sec.
122.21(r)(14) requires this demonstration to include the Entrainment
Characterization Study at Sec.  122.21(r)(9). The Director may
determine additional data and information, including data collection,
is necessary to make the demonstration.
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    \91\ Note that a new unit may construct a new intake structure
or utilize capacity from an existing intake structure. For the
former, the requirements of Sec.  125.94(e)(1) are simple to
conceptualize and apply. But for the latter, EPA clarifies that the
new unit requirements only apply to that portion of the flow that is
serving the new unit. For a new unit using an existing intake
structure that chooses to comply using Sec.  125.94(e)(1),
demonstrating that the new unit achieves the required reduction in
flow should be a relatively simple exercise in identifying intake
flows and the distribution of cooling water from the intake
structure. For a new unit using an existing intake structure that
chooses to comply using Sec.  125.94(e)(2), the facility would
demonstrate that it has reduced entrainment for that portion of the
intake flow serving the new unit by 90 percent; the facility would
not be required to reduce entrainment for the flow of the entire
intake structure by 90 percent, unless the Director makes such a
site-specific determination for entrainment at the existing units as
well.
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D. When are permit application studies due?

    The owner or operator of a facility applying for reissuance of a
permit must submit the information required at Sec.  122.21(r) to the
Director no later than 180 days before the current permit expires.
Those facilities that were subject to the section 316(b) Phase II rule
from February 16, 2004 until suspension of that rule on July 9, 2007
were already collecting some information required at Sec.  122.21(r).
EPA has structured this rule to take advantage of those data and
expects facilities to use them when they satisfy requirements for
permit applications.
    In some cases, required permit application information might have
been collected, but reports might not have been generated or finalized
prior to the rule suspension in 2007. Further, facilities not subject
to the Phase II rule (e.g., existing power plants below 50 mgd DIF and
all existing manufacturers) might not have collected this information
or might not have collected information to identify permit operating

conditions. In those cases, facilities would have to collect additional
data in order to have two years of biological data collection. EPA
expects associated studies and reports will take several additional
months to complete. For this reason, EPA has established a provision
for permit application submittal for a permit expiring prior to July
14, 2018, allowing the Director flexibility to delay application
requirements based on a showing by the owner or operator that it could
not develop the information by the time required for submission of the
permit application. The Director would then establish a schedule for
submission of the delayed permit application requirements. EPA notes
that the Director has the discretion to require additional studies,
data collection, or an on-site inspection as part of the permit
process.
    Facilities whose permit expires after July 14, 2018 would submit
all required materials in Sec.  122.21(r) with their permit renewal
application.
    New units at existing facilities must submit the information
required at Sec.  122.21(r) to the Director no later than 180 days
before commencing operation of the new unit. Because these units are
being constructed at a facility that is already operating, the facility
will have already submitted many of the permit application materials.
The addition of a new unit would require an update of or supplement to
permit application materials that have already been submitted. New
units take significant time and resources to plan, design, and
construct; therefore the final rule does not have a provision to waive
permit application requirements based on a showing by the owner or
operator that it could not develop the information by the time required
for submission of the permit application. For permit renewals
subsequent to the first permit issued under today's rule, the new unit
would be included in the assessment of the entire facility and would no
longer require unique permit application submissions. As discussed
previously, the owner or operator is encouraged to submit applications
well in advance of the 180 day requirement to avoid delay.
    EPA is aware that some intake structures withdraw from a manmade
lake or reservoir that is stocked and managed by a State or Federal
natural resources agency. In some cases, the biological
characterization of the source water is heavily influenced by the
actions of the natural resources agency. Further, the results of
biological data collection and studies may be confounded by such
actions. Today's final rule at Sec.  125.95(a)(3) gives the Director
discretion to waive some or all of the permit application requirements
of Sec.  122.21(r) in such circumstances.
    In permit terms subsequent to the first permit issued under the
final rule, the facility will re-submit the Sec.  122.21(r) permit
application studies, while the rule still includes two years of
biological data collection for some facilities. In this manner, the
biological characterization over time would be routinely evaluated,
i.e., every 5 years under a standard permit cycle. To reduce the burden
of such data collection, however, the final rule provides that the
owner or operator of a facility may submit a request to the Director to
reduce the information required. See 40 CFR 125.95(c). In most cases,
EPA anticipates the facility would make any such request prior to
conducting its two years of biological data collection. Therefore the
request for reduced information requirements must be submitted to the
Director at least two years and six months before the expiration of the
facility's NPDES permit. The Director may approve such a request if
conditions at the facility and in the waterbody remain substantially
unchanged since the previous permit application.\92\ EPA expects the
Director would assess the relevant previously submitted information and
determine whether it remains representative of current source water,
intake structure, cooling water system, and operating conditions.
Accordingly, the Director may accept or reject any part of the request.
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    \92\ The presence of any habitat designated as critical, or
species listed as threatened or endangered after issuance of the
current permit (whose range of habitat or designated critical habit
includes waters where a facility intake is located) constitutes
potential for a substantial change that must be addressed by the
owner/operator in subsequent permit applications, unless the
facility received an exemption pursuant to 16 U.S.C. 1536(o) or a
permit pursuant to 16 U.S.C. 1539(a) or there is no reasonable
expectation of take.
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E. How will the director determine the best technology available for
minimizing adverse environmental impacts?

1. Review and Approval of Permit Application Materials
    Under today's rule, the Director will review all materials
submitted by an existing facility with its permit application to
determine appropriate NPDES permit conditions and requirements to
minimize impingement mortality and entrainment. As stated at 40 CFR
125.98(a), the Director shall not issue a permit before receiving a
permit application form and any supplemental information which are
completed to his or her satisfaction (see existing Permit Application
and Special NPDES Program Requirements at 40 CFR 122.21(e)).
    Facilities with a design intake flow at or below 2 mgd will
continue to have permit conditions set on a case-by-case, best
professional judgment basis under 40 CFR 125.90(b) and 401.14. For such
facilities, however, the Director may choose to apply some portions of
the permit application conditions in today's rule to aid in the BPJ
determination.
    The Director is encouraged to expeditiously provide any comments on
submitted materials so the facility can make responsive modifications
to its information gathering activities. For permit applications
subsequent to the first permit issued under today's rule, the Director
could indicate whether reduced or different information must be
submitted with the permit application. More specific responsibilities
are described below:
    a. If the Director has made a BTA determination for entrainment
before the effective date of the rule, and substantially the same
information was already submitted and considered by the Director in
making that determination, under Sec.  125.98(g) the Director may
proceed with the Determination of BTA without requiring the owner to
submit the information required in Sec.  122.21(r).
    To clarify further, EPA has included a ``transition'' provision at
Sec.  125.98(g) of today's rule that makes it clear that for any
facility that has submitted a permit application before the effective
date of the regulation, the Director may select the best approach to
development and implementation of the next permit. These provisions are
intended to avoid any unnecessary delay in recently submitted permit
applications or draft permits. EPA expects that facilities will
continue with any data collection requirements, study requirements, and
schedules in recently issued permits.
    b. If the Director establishes a compliance schedule under Sec.
125.94, the Director will establish a schedule that sets requirements
as soon as practicable. In establishing the schedule, the Director is
encouraged to consider the extent to which those technologies proposed
to be implemented to meet the requirements of Sec.  125.94(d) will be
used, or could otherwise affect a facility's choice of technology, to
meet the requirements of Sec.  125.94(c). Impacts of thermal
discharges, along with other stressors, might be a relevant
consideration when assessing benefits of technologies to reduce impacts
of cooling water intakes or discharges. The Director is also encouraged
to consider energy reliability, transmission capacity, and

grid requirements when establishing a schedule for electric power
generating facilities. The Director may confer with local and regional
electric power agencies and state utility regulators when establishing
a schedule for electric power generating facilities (see DCN 10-6860
for information on the approach taken by California). The Director may
determine that extenuating circumstances (e.g., lengthy scheduled
outages, future production schedules) warrant establishing a different
compliance date for any manufacturing facility.
    c. The Director will review the permit application materials and
studies submitted under Sec.  122.21(r) and determine which entrainment
controls are appropriate. Factors that must be considered and factors
that may be considered in making the determination are provided at
Sec.  125.98. The Director must issue a written explanation for the BTA
determination and must make this determination, and any other
information submitted by third parties, available with the permit for
public review. This determination is expected to be issued as part of
the permit's statement of basis under 40 CFR 124.7.
2. Role of Social Cost-Benefit Analysis in Permit Determinations
    In deciding what technology to require a permittee to install to
address entrainment, the Director may undertake an evaluation of social
costs and benefits of implementing such requirements. This analysis
will be based on the information submitted by the applicant,
supplemented by any information submitted by third parties, and
additional information as determined appropriate by the Director. EPA
recognizes the resource limitations faced by permitting authorities and
does not generally expect that the Director would develop additional
information on which to base the evaluation of social benefits and
costs, although the Director may opt to do so. This analysis should
evaluate benefits and costs from the perspective of society as a whole,
rather than costs and benefits accruing to limited parties (e.g., very
local populations or the permittee, which presents a limited set of
information to the Director).
    It is also important to note that the stated preference survey
conducted by EPA which was discussed in the June 12, 2012 Notice of
Data Availability (77 FR 34927) was designed to estimate respondents'
willingness to pay for changes in the health of fish populations and
aquatic ecosystems and be statistically representative at large
(regional and national) scales; the results were not designed to be
statistically representative at the facility level for the assessment
of benefits for individual site-level permitting decisions. Today's
final rule does not require the Director to require a facility owner or
operator to conduct or submit a stated preference survey to assess
benefits. Further, the rule does not limit the Director's discretion to
consider non-water quality impacts in determining whether further
entrainment measures are justified.
    A number of cost elements should be accounted for in assessing the
social cost of entrainment technology implementation. These are
summarized below.
a. Technology Installation Cost
    These peer-reviewed engineering cost estimates of the physical
construction of candidate entrainment technologies at the facility are
required. These costs would be provided by the applicant under Sec.
122.21(r)(10).
b. Installation Downtime Cost
    Installation of closed-cycle cooling systems will often require
facilities to take additional downtime beyond ordinary annual
maintenance downtime. An estimate of downtime cost to the facility is
required under Sec.  122.21(r)(10). EPA expects a facility will
document that portion of downtime that is incremental to any downtime
the facility already incurs due to, for example, routine maintenance
outages, overhauls, refueling, and periodic replacement of equipment
that is at the end of its useful life. Downtime costs to the facility
include the value of lost production (e.g., electricity) minus any
variable cost savings, as well as any other costs to the facility
associated with downtime (shutdown and startup routines, special
maintenance protocols, etc.) minus any savings associated with
downtime. If they are considered in the social costs analysis, downtime
costs must be adjusted to reflect production made up by other
facilities or firms, because these temper the real resource costs from
society's viewpoint. The cost of downtime is determined on a different
basis for social cost. Specifically, the cost of downtime to society is
the cost incurred for other facilities and generating units to make up
the electricity or manufactured goods that would have otherwise been
generated by the facility minus the cost that would have otherwise been
incurred by the facility incurring downtime. This difference in cost
reflects the additional cost, if any, that society must pay to generate
the replacement goods, and may differ substantially from the cost of
downtime to the facility.
c. Energy Penalty Cost
    Operation of closed-cycle cooling systems may impose an energy
penalty. EPA is using energy penalty to mean only the opportunity costs
associated with reduced power production due to derating (turbine
backpressure). Energy penalty does not include the costs to operate
pumps and fans associated with closed-cycle cooling, which are
operation and maintenance costs (and covered below). Under well-
established principles in benefit-cost analysis, the cost of the energy
penalty to the facility is not the opportunity cost to society.
Instead, the cost to society is the cost of generating the electricity,
whether incurred by the regulated facility or another facility, that is
no longer available for consumption because of the energy penalty. This
cost may be incurred by the facility, if it can increase the energy
input to, and output from, the generating unit to generate the
electricity that is otherwise no longer available for consumption, or
by another generating unit if the regulated unit cannot make up the
electricity. In either case, the social cost of the energy penalty is
the cost of generating the electricity that would otherwise be
available for consumption except for the energy penalty. Again, an
assessment of these costs would be determined under the Sec.
122.21(r)(10) demonstration.
d. Operation and Maintenance Costs for the Entrainment Technology
Equipment
    The cost of energy to operate the entrainment technology for
electric generators should appear in the operation and maintenance
costs, along with other labor and materials costs. In the same way as
described above, the social cost of the energy required to operate
entrainment technology is the cost for generating this electricity, as
it is otherwise no longer available for end-use consumption. This cost
could be incurred by the regulated facility, if it has sufficient
capacity to make up the loss, or by another facility, if the regulated
facility is not capable of generating the electricity that is no longer
available for end-use consumption.
e. Other Administrative Expenses
    This includes additional permitting or reporting expenses, or both.
For social costs, the estimate should include the costs to the facility
and those expected to be incurred by the Director.
    EPA has estimated the Directors' administrative costs in the ICR
for the final rule, as explained in the EA, and

facilities may adopt a similar approach to estimating these costs at
the permit level. For assessing social cost, the cost elements outlined
above would typically be accounted for on a real cost basis--that is,
pre-tax and without adjusting for future inflation. Costs are tallied
over an appropriate time frame, which will typically be the expected
useful life of the technology installation or the remaining life of the
facility, if less. Costs should be calculated as both net present value
and annualized values, using an appropriate social discount rate. The
applicant should document the basis for the discount rate chosen, and
its methodology and calculations.
f. Benefits
    In assessing the benefits of entrainment technology installation,
the Director would assess the value to society from the reductions in
impingement mortality and entrainment that would result from
installation of a closed-cycle cooling system, fine mesh screens, or
other entrainment technologies. All benefits, including monetized,
quantified and qualitative benefits, should be considered in this
assessment. The benefits assessment would typically look at a range of
potential benefit categories, including increased harvest for
commercial fisheries, increased use values for recreational fisheries,
and nonuse values (existence and bequest values). The latter may be
difficult to quantify or monetize. If appropriate data are available
from benefits transfer or conducting stated preference studies or other
sources that can be applied to the site being evaluated, these should
be used to monetize nonuse values. Otherwise, nonuse values should be
evaluated quantitatively and/or qualitatively. Quantitative analysis,
even without monetization, can be quite useful in evaluating nonuse
benefits. For example, quantifying impacts to forage and threatened and
endangered species, and other indirect impacts on the aquatic
environment, might allow the Director to derive a much more complete
understanding of benefits as compared to a qualitative narrative, even
if not directly comparable to monetary costs.
    Quantifying and valuing the benefit categories listed above
involves significant challenges, as described in the BA. For example,
assessing the productivity and value of commercial fisheries involves
estimating the expected increases in commercial yield of economically
valued species over time as a result of reduced impingement mortality
and entrainment, and valuing these at market prices minus any
incremental production costs associated with the incremental catch.
Similarly, assessing recreational use benefits involves estimating the
improvements in recreational fishing opportunities resulting from
reduced impingement mortality and entrainment, and assigning a value to
these improvements. The value assignment is based on the estimated
population profile--in particular, number and proximity to affected
water resources--of recreational users, the availability of alternative
competing water resources for recreational usage, and the resulting
estimated change in demand for use and value of the affected water
resources based on reduced impingement mortality and entrainment and
increased recreational fishing performance. EPA acknowledges this could
be difficult to do even on a site-specific basis.
    Nonuse benefits, which encompass existence and bequest values,
include impacts in such areas as population resilience and support,
nutrient cycling, natural species assemblages, and ecosystem health and
integrity. Nonuse values include improving the survival probability of
a threatened or endangered species if present in the vicinity of the
facility. Benefits might also need to be assessed beyond the vicinity
of the facility's intake if migratory species are affected by the
intake. Residual impacts of thermal discharges might also be
appropriate to consider in the social benefits calculation.
    In much the same way as described for the social cost assessment,
social benefits are tallied yearly over the expected performance life
of the compliance technology. This tallying should account for the
``phase-in'' of benefits (e.g., benefits may build up over time as the
impingement mortality and entrainment reductions affect commercial
fisheries productivity). Benefits are computed on a present value basis
and annualized using an appropriate discount rate as described above.
The same discount rate should be used for benefits and costs. Often, it
is appropriate to calculate benefits and costs using more than one
discount rate. For example, for regulatory impact analysis, OMB
recommends that Federal agencies use both a 3 percent and a 7 percent
rate. However, comparisons between specific benefit and cost numbers
should always involve values computed using the same rate.
    The resulting estimates of social cost and benefits must be
considered in determinations on whether to require a permittee to
install entrainment technology and the specific level of entrainment
technology to be installed. The Director may reject otherwise available
technologies as the BTA requirements for entrainment controls if the
social costs of compliance are not justified by the social benefits, or
if there are other adverse impacts that cannot be mitigated that the
Director deems to be unacceptable. If all technologies considered have
social costs not justified by the social benefits, or have unacceptable
adverse impacts that cannot be mitigated, the Director may determine
that no additional control requirements are necessary beyond what the
facility is already doing. The Director should document the basis for
such a determination and include it in the public notice for the draft
permit.
3. Streamlined Process
    The process for complying with the impingement mortality standards
is expected to be highly streamlined. As shown in Exhibit VIII-1, EPA
expects more than 99 percent of facilities will comply by one of the
six compliance options that do not require continual biological
compliance monitoring (one of the three compliance alternatives based
on pre-approved technologies or one of the three streamlined compliance
alternatives). If a facility chooses to comply by operating a modified
traveling screen, the Director will review the impingement technology
performance optimization study, including the identification of
species, duration and structure of the study, and any monitoring
requirements.
4. De Minimus Provision
    The Director may, based on a review of data submitted under Sec.
122.21(r), conclude that the documented rate of impingement at the
cooling water intake structures is so low that no additional controls
are warranted. As described in section I.A.H, low flow facilities may
in particular be candidates for such consideration, although the
authority of the Director is not limited to low flow facilities. The
Director may want to consider facility withdrawal rates in relation to
the mean annual flow of the river and possible co-location with other
CWISs when making a de minimis determination. Notice of this
determination would be included in the draft permit made available for
public comment, and the Director's response to any comment on this
determination must be included in the record for the final permit. EPA
considers low rates of impingement to be measured as an organism or
age-one equivalent count, and not as the effect of impingement on

fish populations. The Director may require data collection to
demonstrate support for a de minimis level of impingement. In addition,
EPA does not expect that a de minimis exemption would apply to
facilities with no technology present other than trash racks, a
technology that nearly all facilities employ. In making a determination
that no additional controls are warranted, the Director may wish to
consider factors such as whether the waters are subject to a TMDL for
an aquatic life use, the waters are not attaining a designated use, and
there would be more than minor detrimental effects on threatened or
endangered species or critical habitat. The Director will still
establish proper operation and maintenance conditions in the permit
whenever making a de minimis finding that no additional controls are
warranted. EPA notes that the de minimis provision for impingement does
not necessarily mean a facility has a de minimis level of entrainment.
The life stages affected by impingement are different than those
affected by entrainment, and low counts of impingeable life stages do
not always mean the counts of entrained organism are similarly low.
Since the entrainment requirements are already determined by the
Director for each site, EPA concluded that specific regulatory language
for de minimis entrainment was unnecessary.
5. Low Capacity Utilization Units
    The Director may consider less stringent controls for intakes
dedicated to low capacity utilization rate (CUR) power generating
units. If an existing facility has a cooling water intake structure
used exclusively for one or more existing electric generating units,
each with an annual average capacity utilization rating of less than 8
percent averaged over a 24-month block contiguous period, the owner or
operator may request that the Director establish BTA standards for
impingement mortality for that cooling water intake structure which are
less stringent than Sec.  125.94(c)(1) to (c)(7). When determining the
permit's IM requirements associated with the low CUR unit, the Director
may consider, after conferring with any appropriate state co-regulators
(such as public utility commissioners) and with regional transmission
organizations, independent system operators or other planning
authorities, the significance of the unit's operation to the overall
reliability of electric power in the area.
    In addition, in determining the IM requirements associated with a
low CUR unit, the Director should consider any seasonal factors for
affected species that might justify seasonal limits on the unit's
operation, for example any increased impacts resulting from the unit's
operation during spawning runs. Also, when considering the presence and
potential effects to threatened and endangered species, the Director
should consider whether the life stages present at the location are at
risk of being impinged or entrained at the low CUR unit's cooling water
intake.
    In the event that the Director determines less stringent controls
for intakes dedicated to low capacity utilization power generating
units are appropriate, they should consider, at a minimum, the
following in establishing controls:
    Strategies for minimizing water withdrawal during stand by periods
of operation, startup/shutdown, and on-line periods of operation;
    The effectiveness of installing variable speed pump drives to
reduce water withdrawals during all periods of operation, particularly
during stand-by periods of operation; and
    The effectiveness of installing alternative equipment (e.g.
behavioral deterrents) to minimize impingement mortality.
    The owner or operator would demonstrate whether they have an intake
only serving one or more low capacity utilization power generating
units in permit application requirements at Sec.  122.21(r)(3) and (8).
Under Sec.  122.21(r)(6), the owner or operator would indicate a
request that the Director establish alternative BTA standards that are
less stringent than Sec.  125.94(c)(1) through (7). EPA recognizes the
contribution of peaking units in serving peak electricity demands, and
maintaining a reliable electricity grid. However, if peaking units are
in standby mode for long periods relative to periods when they are
generating electricity, the result is a capacity utilization of the
cooling water intake that is greater than the capacity utilization of
the generator. Significant periods of standby could contribute to a
greater impact on aquatic life. While the 8 percent capacity
utilization is an industry standard that distinguishes those units
making the greatest contribution to a smoothly functioning electricity
grid, a Director may still determine that the impacts to aquatic life
are significant enough to deny a request that BTA at that intake should
be less stringent than Sec.  125.94(c)(1) to (c)(7). EPA anticipates
the Director will have the information necessary to determine BTA in
such circumstances based on the permit application requirements,
including but not limited to an identification of the number of days
the cooling water system is in operation, flow on those days, and
seasonal changes in the operation of the system under Sec.
122.21(r)(5) and the biological information under Sec.  122.21(r)(4).
    As discussed previously, the Director will determine the BTA for
entrainment for low CUR units on a site-specific basis. EPA expects
that many of the same factors discussed above--including the
significance of the unit's operation to the overall reliability of
electric power in the area, the diversity of fuels available for the
unit, and the impact of the costs of any potential entrainment
requirements on the unit's cooling water intake structure on overall
reliability of electric power in the area--will be relevant in making
site-specific BTA entrainment determinations for low CUR units. The
Director may consider the factors at Sec.  125.98(f)(3) when making
these determinations for low CUR units, which includes grid
reliability, among other factors.
6. Monitoring
    The Director will review any impingement mortality and entrainment
monitoring reports submitted by the facility to ensure ongoing
compliance. EPA is shifting toward an electronic discharge monitoring
report system, and many of the impingement mortality and entrainment
standards can be incorporated into the discharge monitoring report
itself, rather than requiring a separate report. Except for facilities
choosing alternatives Sec.  125.94(c)(7), detailed biological data
collection would only be included as part of the facility's permit
application submission and not for compliance purposes. The Director
has the discretion to request additional information, including
inspection of the facility, at Sec.  125.95(d) (i.e., permit
application and supporting information requirements) and Sec.
125.96(c) (i.e., additional monitoring requirements).
7. Nuclear Units
    The rule includes a provision that permits the owner of a nuclear
facility to demonstrate to the Director that compliance with the rule
would result in a conflict with safety requirements for their facility.
See Sec.  125.94(f). EPA anticipates that this provision would be
implemented as follows. Initially, the Director will draft a permit and
will share the draft permit with the owner or operator of the nuclear
facility. Upon reviewing the draft permit, the owner or operator will
determine whether in their view a conflict with a safety requirement
established by the Nuclear

Regulatory Commission, the Department of Energy or the Naval Nuclear
Propulsion Program exists. If a conflict exists, the owner or operator
should communicate the conflict to the NRC, Department or Program and
the Director. In all cases, whether a conflict exists or not, the
Director should notify the NRC, Department or Program and the owner or
operator of the facility that he or she wishes to informally confer
regarding the permit. Such interactions should be scheduled, conducted
and documented. Where a conflict is identified, the Director would make
a site-specific BTA determination.

F. What are example permit conditions and compliance monitoring for
impingement mortality?

    As previously discussed, the owner or operator must comply with BTA
standards as soon as practicable on a schedule of requirements
established by the Director. EPA did not specify dates by which the BTA
standards for impingement mortality must be met because the specific
method of compliance with the BTA standards for impingement mortality
is tied to the determination of BTA requirements for entrainment.
Further discussion of this alignment of compliance deadlines is
provided in Section A. Today's final rule provides for several methods
of compliance with the BTA for impingement mortality. This section
discusses each of the methods for compliance, how they follow from the
permit application requirements at Sec.  122.21(r), and any minimum
monitoring and reporting requirements associated with each method.
1. Closed-Cycle Recirculating System
    In this method of compliance, an existing facility must operate a
closed-cycle recirculating system as defined at Sec.  125.92(c). The
facility would indicate the choice to use this compliance method under
Sec.  122.21(r)(6) in its permit application. As specified in Sec.
122.21(r)(1), the facility would need to submit Sec.  122.21(r)(9)
through (13), if it exceeds 125 mgd AIF and these requirements are not
waived by the Director. The information still required at Sec.
122.21(r)(2) to (8) is considerably less burdensome. The monitoring
must be representative of normal operating conditions, and must include
measuring cooling water withdrawals, make-up water, and blowdown flows.
The facility must monitor actual intake flows at a minimum frequency of
daily, or may monitor the representative cycles of concentration at a
minimum frequency of daily. These monitoring data would be used by the
Director to determine that make-up and blowdown flows have been
minimized. The owner or operator would submit these data with their
existing DMR or equivalent state report. Facilities complying using
closed-cycle cooling are not subject to biological compliance
monitoring unless otherwise specified by the Director (see Sec.
125.96(c)).
2. 0.5 Feet per Second Through-Screen Design Velocity
    In this method of compliance, the facility must operate a cooling
water intake structure that has a maximum design through-screen intake
velocity of 0.5 feet per second. The facility must submit information
under Sec.  122.21(r) to the Director that demonstrates that the
maximum design intake velocity as water passes through the structural
components of a screen measured perpendicular to the screen mesh could
not exceed 0.5 feet per second. The maximum velocity must be achieved
under all conditions, including during minimum ambient source water
surface elevations (based on BPJ using hydrological data) and during
periods of maximum head loss across the screens or other devices during
normal operation of the intake structure.
    EPA notes a cylindrical wedgewire screen, in general, is designed
for 0.5 feet per second. In Phase II, EPA pre-approved wedgewire
screens under specific operational conditions. Today's final rule
simplifies the demonstration requirements for a facility employing
cylindrical wedgewire screens to that of demonstrating the maximum
design through-screen velocity is 0.5 feet per second. As another
example, a facility may have pumping and piping constrictions that
physically limit the design intake velocity to less than 0.5 feet per
second. The Director may choose to establish permit conditions that
address the physical limitations of the intake, such as requiring a
pump be removed from service, or that only one of two (redundant) pumps
may operate at any time. Facilities choosing to comply under this
section do not have monitoring requirements under this section.
3. 0.5 Feet per Second Through-Screen Actual Velocity
    This method of compliance is similar to the design velocity
alternative discussed above, except that the intake's maximum design
velocity can exceed 0.5 fps, as long as the intake is operated such
that the actual, measured velocity does not. As an example, a facility
may have originally been constructed with a maximum design intake of
1.0 feet per second, but now, because it has retired generating
capacity but not pumps, may only withdraw cooling water such that the
actual intake velocity at the intake never exceeds 0.5 feet per second.
This would constitute compliance with the impingement mortality
standard. The maximum velocity must be achieved under all conditions,
including during minimum ambient source water surface elevations (based
on BPJ using hydrological data) and during periods of maximum head loss
across the screens or other devices during normal operation of the
intake structure.
    Monitoring the velocity at the screen face or immediately adjacent
to the screen face must be conducted at a minimum frequency of daily.
Monitoring of the approach velocity does not meet this requirement.
However, in lieu of velocity monitoring at the screen face, the owner
or operator may calculate the through-screen velocity using intake
water flow, water depth, and the screen open area. EPA is requiring
this point of measurement to ensure that fish are actually able to swim
away (not into an embayment from which they cannot escape) from the
location within the intake structure at which they are most susceptible
to being impinged.
    Under today's final rule, the Director may authorize the facility
to exceed the low velocity compliance alternative for brief periods for
the purpose of maintaining the cooling water intake system, such as
backwashing the screen face. In this compliance option, facilities are
not subject to biological compliance monitoring unless otherwise
specified by the Director (see Sec.  125.96(c)).
4. Existing Offshore Velocity Cap
    In this method of compliance, facilities will submit information
under Sec.  122.21(r) that they operate an offshore velocity cap that
meets the definition at Sec.  125.92(v) and that was installed prior to
the effective date of this rule. The definition of offshore velocity
cap includes the requirement that the velocity cap be located a minimum
of 800 feet offshore. The velocity cap must include devices to exclude
marine animals, such as bar screens. The velocity cap must be designed
to change the direction of water withdraw from vertical to horizontal,
thereby creating velocity patterns that can be sensed and trigger an
avoidance response by fish and other aquatic organisms. Intake flow
must be monitored at a minimum frequency of daily. This information
will confirm the intended velocity patterns are created. In this
compliance option, facilities are not subject to biological compliance
monitoring

unless otherwise specified by the Director (see Sec.  125.96(c)).
    EPA notes that facilities choosing to construct a velocity cap at
an offshore location after the effective date of this rule would use
compliance options Sec.  125.94(c)(6) (Systems of Technologies as the
Site-specific BTA for Impingement Mortality) or Sec.  125.94(c)(7)
(Impingement Mortality Performance Standard).
5. Modified Traveling Screens
    In this method of compliance, a facility must first operate a
modified traveling screen that meets the definition at Sec.  125.92(s).
The definition identifies and requires those features of a traveling
water screen that provide for an appropriate level of fish protection:
collection buckets (or equivalent) to minimize turbulence to aquatic
life; guard rails or barriers to prevent loss of fish from the
collection system; screen panel materials such as smooth woven mesh,
drilled mesh, molded mesh, or similar materials to protect fish from
descaling; continuous or near-continuous rotation of screens and
operation of collection equipment to recover impinged fish as soon as
practical; low pressure wash or vacuum to remove collected organisms
from the screens; fish handling and return with sufficient water flow
to return fish directly to the source water in a manner that does not
promote predation or the re-impingement of the fish, or a large
vertical drop. EPA intends for this definition to generally include
modified Ristroph screens (including Geiger screens, Beaudrey WIP
screens, and Hydrolox screens), dual flow screens, and rotary screens.
    Modified traveling screens with a fish return and handling system
is the technology basis for the impingement mortality standard,
therefore the EPA fully expects biological monitoring of a properly
designed, built, and operated modified traveling screen would
consistently be able to meet the impingement mortality performance
standard. If EPA were to simply set a performance standard based on the
numeric performance levels achievable by modified traveling screens, a
facility would have to conduct continual biological monitoring to
demonstrate compliance. A far more efficient way to demonstrate
compliance would be for facilities to optimize the operation of their
technologies for their site-specific conditions and identify the
conditions that distinguish proper operation at their facility. The
optimized operation of the technology would be largely demonstrated
through the biological data collection and studies required in the
permit application at Sec.  122.21(r)(4) and (6)(i), including an
impingement technology performance optimization study. Biological data
collection should follow the sampling protocols described in section7
below.
    The optimized operation documented by the impingement technology
performance optimization study will result in more than just meeting
the impingement mortality standard, and results in a facility achieving
the best possible performance.\93\ The biological data collection and
analysis in the impingement technology performance optimization study
will identify the operating conditions that result in optimized
performance, such as fish sluicing spray pressures, rotation speed and
frequency of the screens, angle of the fish sluicing sprays, fish
return trough water flows, and fish return trough location.\94\ The
Director will then establish these operating conditions as permit
conditions, along with an equipment inspection condition to assure
proper functioning of the technology. As long as the permit conditions
are met, the EPA does not expect any biological compliance monitoring
will be required, unless otherwise specified by the Director, for
example, for the protection of shellfish or fragile species (see Sec.
125.96(c)). Note that EPA does not intend for facilities to install
closed-cycle cooling solely for the purpose of meeting the IM
requirements.
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    \93\ As demonstrated by the numerous studies included in the
record for today's final rule, many facilities are able to achieve
less than 10 percent impingement mortality, a performance level
comparable to the impingement mortality of closed-cycle cooling.
Merely requiring facilities to achieve a numerical performance
standard through modified traveling screens creates disincentives to
perform better.
    \94\ EPA also requires the entrapment of organisms, as well as
organisms that are carried over the screens, to be counted as
impingement mortality.
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6. Systems of Technologies as the BTA for Impingement Mortality
    In this method of compliance, a facility must demonstrate a system
of technologies is employed that will meet the impingement mortality
standard. This option will allow a facility the flexibility to choose
the systems approach of technologies, management practices, and
operational measures it will use to demonstrate compliance, including
but not limited to flow reductions, intake location, behavioral
deterrents, unit closures, seasonal operations, and newly installed
velocity caps. Like the compliance option for modified traveling
screens, the optimized operation of the system of technologies will be
largely demonstrated through the biological data collection and studies
required in the permit application at Sec.  122.21(r)(4) and (6)(ii).
However, the analysis and studies for combining the performance of
varied technologies is more involved.
    If the system of technologies includes credit for reductions in the
rate of impingement by the system, the impingement technology
performance optimization study required at Sec.  122.21(r)(6)(ii) will
provide an estimate of those reductions including relevant supporting
documentation. The estimated reductions in rate of impingement must be
based on a comparison of the facility's system to a once-through
cooling system with a traveling screen whose point of withdrawal from
the surface water source is located at the shoreline of the source
waterbody. EPA expects Phase II facilities will use information already
collected as part of their calculation baseline (69 FR 41594, July 9,
2004). In addition, the study must include two years of biological data
collection demonstrating the rate of impingement resulting from the
system. For this demonstration, data collection must be conducted no
less frequently than monthly. The Director may establish more frequent
data collection or a longer period of study.
    If the system of technologies includes credit for reductions in
impingement mortality already obtained at the facility, the study must
include two years of monthly biological data collection demonstrating
the level of impingement mortality the optimized system achieves.
Biological data collection must be representative of the impingement
and the impingement mortality at the intakes and should follow the
sampling protocols described in section 7 below. The impingement
technology performance optimization study must provide a description of
any sampling approach used in measuring impingement mortality,
including a taxonomic identification to the lowest taxon possible of
all organisms to be sampled; the method in which naturally moribund
organisms are identified and taken into account; and the method in
which mortality due to holding times is taken into account. In
addition, the study must describe how the location of the cooling water
intake structure in the waterbody and the water column are accounted
for in the sampling locations. EPA requires the entrapment of
organisms, as well as organisms that are carried over the screen, to be
counted as impingement mortality.
    If the system of technologies specifically includes flow reduction
to reduce impingement, the impingement

technology performance optimization study must include two years of
intake flows, measured daily, as part of the demonstration, and must
describe the extent to which flow reductions are seasonal or
intermittent. The rule clarifies that credit for flow reductions must
result from actual reductions in flow, therefore the AIF will be used
as a point of comparison, and not the DIF. The study must document how
the flow reduction results in reduced impingement, and how the
reduction in impingement has reduced the site-specific impingement
mortality. Today's final rule at Sec.  125.98(f)(3)(iii) further
clarifies that credit in reduced impingement or impingement mortality
resulting from unit closures will be valid for a period of 10
years.\95\ This is also reflected in permit application requirements
for an owner or operator planning to retire the facility in the current
permit term at 40 CFR 122.21(r)(1)(ii)(F), or in the following permit
cycle at 40 CFR 122.21(r)(1)(ii)(G).
---------------------------------------------------------------------------

    \95\ Because a permit may be administratively continued or may
not be issued every 5 years, EPA has specified 10 years rather than
two permit cycles to avoid facilities from taking credit for a unit
closure that potentially occurred decades prior.
---------------------------------------------------------------------------

    The Director must determine the system of technologies, management
practices, and operational measures that is the best technology
available for impingement reduction at the site. As the basis for the
Director's determination, the facility must demonstrate that the system
of technology has been optimized to minimize impingement mortality of
all non-fragile species. In addition to the impingement technology
performance optimization study, the Director may also use the
biological source water characterization and/or the entrainment
characterization studies in the permit application. EPA expects the
Director's decision will be informed by comparing the impingement
mortality data under Sec.  122.21(r)(6)(ii) to the impingement
mortality performance standard that would otherwise apply under Sec.
125.94(c)(7).
    In addition, the impingement technology performance optimization
study requires documentation of the percent impingement mortality
reflecting optimized operation of the total system of technologies,
operational measures, and best management practices and all supporting
calculations. The following example illustrates how these provisions
will adjust for flow, location, and other technologies in demonstrating
the IM performance for a system of technologies.
    The example uses values that simplify the calculations to better
illustrate the adjustments, and are not intended to reflect values that
EPA expects at any facility. To simplify the example further, the
facility has only fish and does not have shellfish in its source
waters. EPA has chosen a hypothetical facility that examined each
change in a separate study.\96\ The hypothetical facility intake is
located at a submerged offshore location, has an acoustical deterrent,
and installed variable speed drives. For the purposes of this example,
the facility has completed sampling at the forebay for two years as
part of Sec.  122.21(r)(4) and (6). During the most recent 12 months,
the counts of non-fragile species totals 40,000 impinged fish. During
the 24-hour holding period following each monthly sample collection,
the total fish that died were counted, for a total of 12,000 dead fish
for the preceding 12 months. The facility then calculated the average
IM for the preceding 12 months at 30 percent as follows:
---------------------------------------------------------------------------

    \96\ EPA recognizes that facilities often examine the combined
effect of two or more technologies (e.g., deterrents and offshore
location) within a single study. In applying these provisions, the
facility could use the outcomes associated with the combined
performance of multiple technologies, but this would result in
permit conditions that would also be combined.
[GRAPHIC] [TIFF OMITTED] TR15AU14.000

    To adjust the observed percent IM for a submerged offshore location
and acoustical deterrent, the facility first extracts information from
its previously conducted studies related to performance and calculation
baseline. Alternatively, the facility could conduct a performance study
during the same two year period in which it conducts its biological
data collection as part of the permit application requirements at Sec.
122.21(r). For the submerged offshore location adjustment, fish density
and flow data show the offshore location reduces the rate of
impingement for all species by 4,000 fish annually. For the acoustical
deterrent, performance data show a reduction in the rate of impingement
of fish by 11,000 organisms annually. For purposes of this example,
assume none of the 15,000 fish are assumed to contribute to further
mortality; in other words, all of the fish that avoided impingement in
the first place survive. Therefore, the facility has reduced
impingement by 15,000 fish (i.e., sum of both submerged offshore
location and acoustical deterrent). The facility then takes credit for
this reduction by adding the forgone impingement to the denominator of
the percent IM calculations as follows:
[GRAPHIC] [TIFF OMITTED] TR15AU14.001

    In summary, calculating percent IM at the forebay yields a 30
percent IM, and then applying the performance for existing technologies
shows the effective percent IM is actually 22 percent. Next, to adjust
for the variable speed drives, the facility has determined from flow
monitoring that the volume of cooling water flow has been reduced by 11
percent. In this example, assume the flow reduction does not vary
considerably each month. The volume of reduced flow multiplied by the
density of fish near the intake is calculated each month for 12 months,
and the facility projects that the reduced flow excludes an additional
8,000 fish from impingement each year. Then the facility would apply
the reduction in annual counts of impinged fish to the denominator, as
follows:
[GRAPHIC] [TIFF OMITTED] TR15AU14.002

    Thus, the facility's site-specific system of technologies including
optimized operation of acoustical deterrents has a total system
performance of 19 percent annual impingement mortality. This example is
intended to illustrate how facilities would obtain credit for existing
technologies in a systems approach. While this example includes
acoustical deterrents, it does not imply that acoustical deterrents are
an appropriate technology for all facilities. EPA expects a facility
will use the required two years' worth of monthly biological data
collection and studies to conduct a similar analysis for each month.
The minimum required data collection and studies will result in annual
average performance calculations for 12 consecutive months. The
facility will use this information as part of its demonstration to the
Director.
    If the Director determines the system of technologies, management
practices, and operational measures is the best technology available
for impingement reduction at the site, the Director will establish
specific operating conditions as permit conditions, along with
appropriate equipment inspection conditions to assure proper
functioning of each technology. For example, a system with acoustical
deterrents would likely have permit conditions related to frequency of
tones, volume, location, and frequency of operation of the acoustical
deterrents. The Director will also establish monitoring requirements
for intake flow and velocity where such measures are an important part
of the system of technologies, such as the case of variable speed
drives. For example, a system that includes seasonal flow reductions
would likely have permit conditions for flow monitoring. As long as the
permit conditions are met, the EPA does not expect any biological
compliance monitoring will be required, unless otherwise specified by
the Director (see Sec.  125.96(c)).
7. Impingement Mortality Performance Standard
    In this method of compliance, facilities are required to monitor to
demonstrate compliance with the impingement mortality performance
standard at Sec.  125.94(c)(7) by demonstrating a 12-month average
mortality of 24 percent or less. The facility is required to monitor at
a minimum frequency of monthly, unless a greater frequency is specified
by the Director. For each monitoring event, the facility would
determine the number of non-fragile organisms that are collected or
retained on sieve with a maximum spacing of 0.56 inches (i.e., that are
impinged [I]), and the number that die after impingement (i.e.,
impingement mortality [IM]). The facility must establish a post-
impingement holding period of 18 to 96 hours otherwise specified by the
Director. Under the definition at Sec.  125.92(b), all life stages of
fish and shellfish excludes specified nuisance species from the totals
for both impingement and impingement mortality. Also, as defined at
Sec.  125.92(q), latent mortality means the delayed mortality of
organisms that were initially alive upon being impinged or entrained
but that do not survive the delayed effects of impingement and
entrainment during an extended holding period. Delayed effects of
impingement and entrainment may be due to stresses that include but are
not limited to temperature change, physical stresses, and chemical
stresses. The manner in which latent mortality is counted must be
identified in the Entrainment Characterization Study at Sec.
122.21(r)(9), and must also be counted in the Impingement mortality
performance standard at Sec.  125.94(c)(7). Fish that are included in
any carryover from a traveling screen or removed from a screen as part
of debris removal must be counted as impingement mortality. Fish that
are entrapped by the cooling water intake system must be counted as
impingement mortality.
    The 12-month average of impingement mortality is calculated as the
sum of total impingement mortality over 12 months divided by the sum of
the total impingement over the same 12 months, as shown by the
following equation:
[GRAPHIC] [TIFF OMITTED] TR15AU14.003

    Note that this equation would be applicable to calculating the
annual average for the previous 12 months. Although facilities will be
conducting biological monitoring monthly (or more frequently) and
reporting that data in their discharge monitoring reports, facilities
are not required to meet a monthly impingement mortality performance
standard. Therefore, in this equation, IM is the sum of all impingement
mortality over the course of the previous 12 months, and I is the sum
of all impinged fish for the previous 12 months. If the facility's
calculated annual average percentage impingement mortality is less than
the 12-month average performance standard, it will be deemed to be in
compliance with the 12-month average performance standard.
    In establishing the monitoring requirements, EPA expects any
approved monitoring protocols will

consider the entire daily and (where appropriate) tidal cycles over
which data collection should occur. Typically, facilities have
collected impingement samples continuously for 6 or 8 hours and
repeated this cycle to cover an entire 24-hour period. Stratifying
collection in this manner allows an analysis of the diel variation
exhibited by many aquatic organisms, which may be important. EPA also
expects the approved monitoring protocols will ensure that sampling
occurs during periods of representative intake flow and not during
periods of non-peak flow or scheduled outages.
    The ideal point to measure impingement mortality is the location
where organisms are returned to the waterbody. However, for ease of
sampling and access, EPA envisions that most facilities will collect
samples from the fish return system(s) at some point before the fish
return discharge point. According to the studies in EPA's database, EPA
envisions that facilities will either (1) divert some or all of the
flow from the fish return into a fish collection and holding area, or
(2) place a net or basket fitted with \3/8\-inch mesh spacing in the
fish return and collect and transfer the retained organisms to a
holding tank. While nearly all studies in the record report the use of
\3/8\-inch mesh spacing, as discussed below, the final rule allows the
use of other sieve and mesh spacings with a 0.56 inch maximum opening.
A facility will handle the organisms in the collection device as little
as possible and transfer them to a holding area with conditions as
close as practicable to the source water. The facility will count the
number of organisms in the holding area and subsequently hold the
sample using proper technique \97\ to maintain the health of the
collected organisms.\98\ At a period of 18 to 96 hours after the
initial collection, the facility will count the number of dead
organisms and determine the percentage of organisms that died in
comparison to the total number of organisms measured initially. Any
organisms not collected by the fish handling and return system, such as
entrapped organisms, organisms in the carryover of a traveling screen,
or organisms collected by a high-pressure wash and sent to debris bins,
will be counted as 100 percent impingement mortality. The facility will
keep records of this information and compare its result to the
impingement mortality performance standard at Sec.  125.94(c)(7).
---------------------------------------------------------------------------

    \97\ EPA recognizes that at present, there are no standard
methods for conducting impingement and entrainment studies and that
there can be variability in designing a sampling plan between sites.
However, some elements should be incorporated into any sampling
plan, as outlined in DCN 10-6708.
    \98\ Facilities that divert the flow directly would similarly
pass the flow through a net or debris basket fitted with \3/8\-inch
mesh spacing or would count only organisms that would have been
collected with such a basket or net.
---------------------------------------------------------------------------

    As explained in Section VI, the impingement mortality restrictions
in the final rule are based on the operation of a modified traveling
screen with a fish return. Because EPA wants to ensure that a
facility's monitoring plan is consistent with the technical basis for
today's requirements, EPA is requiring facilities to monitor
impingement mortality using a sample that has been passed through a
sieve or net with no more than 0.56 inches maximum opening, so that
only organisms that do not pass through this mesh size are counted.\99\
In doing so, facilities would retain (and therefore count) only
organisms that would have been impinged on a \3/8\'' mesh screen, which
was the technological basis used for developing the impingement
mortality performance standard.\100\ Facilities could similarly apply a
``hypothetical net'' in that they could elect to count only organisms
that would not have passed through a net with mesh openings less than
0.56 inches. For example, a facility that uses a fine-mesh screen of
0.5 mm or diverts the flow directly to a sampling bay will need to
count only organisms that remain if the flow passed through a net,
screen, or debris basket fitted with \3/8\-inch mesh spacing. EPA
further expects the impingement mortality restrictions could be applied
to other fish protection technologies and provides a compliance route
for future technologies that are better performing.
---------------------------------------------------------------------------

    \99\ For a discussion of how EPA has changed its view of screen
mesh size, see Section III of the proposed rule (76 FR 22188, April
20, 2011). EPA recognizes that smaller organisms that previously
would have passed through a screen and been entrained might be
``converted'' by a fine mesh screen to an impinged organism; because
organisms size would affect the rate of mortality, EPA has chosen
not to rely on definitions of impingement and entrainment based on a
physical process, but instead to define impingement mortality and
entrainment mortality based on organisms sizes.
    \100\ EPA's analysis of impingement survival rates is based on
data from facilities with \3/8\'' mesh screens; the performance
standard may be applied differently at facilities with smaller mesh
size. Therefore, these standards do not provide a disincentive to
facilities from using finer-meshed screens (i.e., screens with a
mesh opening smaller than \3/8\ inch) on their traveling screens. As
long as the organisms that are large enough to have been impinged on
a coarse mesh screen achieve the required survival rates, the
facility will be considered to meet the impingement mortality
requirements.
---------------------------------------------------------------------------

    In today's rule, EPA is including provisions for reduced biological
monitoring. EPA determined that monthly monitoring at a minimum is
appropriate for at least the first full permit term. In permit terms
subsequent to the first permit issued under today's rule, the owner or
operator may request the Director to reduce monitoring requirements
under Sec.  125.95(c). EPA expects the Director would reduce monitoring
requirements as appropriate, if the facility demonstrates that its
operational and biological conditions have remained the same. Given
that the source waterbody may change over time (including hosting
different or increased numbers of individuals or species), the
biological characterization required at Sec.  122.21(r)(4) including
two years of data serves to alert interested parties as to the status
of the waterbody and any changes in the biology of the waterbody. Under
the compliance option (7) impingement mortality performance standard,
EPA expects that as new technologies are successfully demonstrated, in
subsequent permits facilities would request less frequent monitoring,
or be able to incorporate such technologies in a permit application
choosing a Sec.  125.94(c)(6), system of technologies, demonstration.
Once the Director has determined the technology is fully demonstrated
for that site, the facility would therefore reduce their biological
data collection to the minimum required by the permit application at
Sec.  122.21(r) and any monitoring the Director determines to be
appropriate for verifying permit operating conditions.
8. Additional Measures
    Sections Sec.  125.94(c)(8) and (9) provide the Director discretion
to require additional measures to protect shellfish and fragile
species. An example of shellfish protection measures is a barrier net,
including seasonal deployment of such nets. An example of additional
protection measures for fragile species is an acoustical deterrent
system.
9. Summary
    The following Exhibit VIII-4 summarizes the monitoring requirements
for impingement mortality by compliance approach alternative. The
Director has the discretion to require additional monitoring under
Sec.  125.96(c) and (d). Since all permits must have requirements for
visual inspections, these are not included in the exhibit.

   Exhibit VIII-4--Summary of Monitoring Requirements for Impingement
                                Mortality
------------------------------------------------------------------------
       Compliance approach          Type of monitoring      Frequency
------------------------------------------------------------------------
Closed-cycle recirculating system  Intake, makeup and   Daily.
                                    blowdown flows (or
                                    cycles of
                                    concentration).
Velocity (DIF)...................  None...............  None.
Velocity (AIF)...................  Velocity (measured   Daily.
                                    or calculated from
                                    flow).
Velocity cap.....................  Intake flow........  Daily.
Modified traveling screens.......  TBD \a\............  TBD \a\.
Systems of Technologies..........  TBD \b\............  TBD \b\.
Impingement mortality performance  Biological           Monthly.
 standard.                          monitoring.
------------------------------------------------------------------------
\a\ Monitoring requirements may vary, depending on the permit-specific
  operating conditions.
\b\ The monitoring requirements are based on the technologies employed.
  For example, seasonal flow reduction would require flow monitoring.

G. What monitoring is required for entrainment?

    Where the Director establishes entrainment controls, the Director
is required to establish monitoring requirements. The final rule
requires that the permit application studies at Sec.  122.21(r) be
submitted for each permit renewal. For facilities that withdraw 125 mgd
AIF, EPA expects that the Director will use these studies, including
the Source Water Baseline Biological Characterization Data at Sec.
122.21(r)(4) and the Entrainment Characterization Study at Sec.
122.21(r)(9), as a basis for any monitoring requirements for
entrainment. To facilitate the determination of entrainment
requirements for facilities below 125 mgd AIF, a Director may require
the owner or operator to submit some or all of the study requirements
at Sec.  122.21(r)(9) through (13) or variations thereof. The Director
may require additional monitoring necessary to demonstrate compliance
with Sec.  125.94(d), additional measures to protect Federally-listed
endangered and threatened species and designated critical habitat
requirements under Sec.  125.94(g), interim standards under Sec.
125.94(h), and any more stringent standards under Sec.  125.94(i).
    Under Sec.  125.96(d), existing facilities with new units are
required to conduct compliance monitoring to demonstrate flow
reductions consistent with the requirements of Sec.  125.94(e)(1), or
equivalent impingement and entrainment reductions. The Director may
establish flow monitoring or monitoring of cycles of concentration as
discussed in Section F. Such measures will be used to document that the
facility has minimized make-up and blowdown flows.
    For facilities complying under Sec.  125.94(e)(2), the frequency of
monitoring will be determined by the Director and will vary depending
on the facility's chosen method of compliance.
    To meet requirements under Sec.  125.94(e)(2), facilities must
measure AIF to establish a site-specific baseline without any new
technologies or employing additional operational measures. The facility
must also measure the density of entrainable organisms (ED)
at a proximity to the intake that is representative of the entrainable
organisms present without the cooling water intake structure. Samples
will be collected over a 24-hour period to monitor each species as
required by the Director. Samples will be collected no less than
biweekly during the primary period of reproduction, larval recruitment,
and peak abundance identified during the Source Water Baseline
Biological Characterization Data required under Sec.  122.21(r)(4).
Samples will be representative of the cooling water intake when the
structure is in operation. In addition, sufficient samples must be
collected to allow for calculation of 12-month average entrainment
levels. The sampling will measure the total count of entrainable
organisms or density of organisms, unless the Director approves of a
different metric for such measurements. If the abundance varies
seasonally, the Director may require several measurements of
entrainment through the year, from which a 12-month average can be
calculated.
    For the purpose of today's rule, entrainable is defined as any
organism that passes through a sieve with a maximum opening of 0.56
inches. As discussed in Section VI, this would avoid any confusion as
to which organisms are subject to which standards (i.e., requirements
for IM or requirements for E). The regulation specifies that the sieve
used for calculating impingement must be the same sieve used for
calculating entrainment, so all organisms are accounted for. Facilities
can also monitor the latent entrainment mortality in front of the
intake structure. Entrainable organisms passing through the cooling
water intake structure are to be counted as 100 percent entrainment
mortality unless the facility demonstrates to the approval of the
Director that the mortality for each species is less than 100 percent.
    In addition, facilities must monitor the AIF for each intake. The
AIF must be measured at the same time as the samples of entrainable
organisms are collected.
    The following equation illustrates how to calculate a baseline
level of entrainment (EB):

EB = ED x AIF

    Performance commensurate with a closed-cycle recirculating system
(ECCRS) can therefore be determined by reducing EB by the percentage of
flow reduced through the use of a closed-cycle cooling system. For
example, a facility withdrawing make-up water from a freshwater source
(as described above, would achieve a reduction of 97.5 percent) will
calculate its performance as follows:

ECCRS = (EB) x (100 - 97.5) / 100

    The resulting value, ECCRS, is the required level of entrainment
performance (as measured by entrainment mortality). The facility could
implement any combination of flow reduction, technologies, and
operational measures to meet the required level of entrainment
performance. For example, a facility withdraws 200 mgd AIF from a
freshwater river. The annual average entrainment density in the
proximity of the intake structure is 6,400 organisms per 100 cubic
meters withdrawn.

EB = ED x AIF
6,400 organisms/100m3 x (100m3/26,417 gallons) x
200,000,000 gallons per day
= 48 x 106 organisms per day

    The maximum entrainment mortality for a closed-cycle cooling system
is thus

ECCRS = (EB) x (100 - 97.5) / 100
= (48 x 106 organisms per day) x (100 - 97.5) / 100
= 1.2 x 106 organisms per day.

    The minimum required level of performance for demonstrating
entrainment mortality at a comparable level (EC) to a closed-cycle
cooling system is the level corresponding to 90

percent \101\ of the reduction that a facility with a closed-cycle
cooling system could achieve:
---------------------------------------------------------------------------

    \101\ The 90 percent metric is required in Phase I, and adopted
here because new units are subject to requirements similar to the
Phase I requirements. Phase I, at 40 CFR 125.86 specifies, ``reduced
both impingement mortality and entrainment of all life stages of
fish and shellfish to 90 percent or greater of the reduction that
would be achieved through Sec.  125.84(b)(1) and (2).''

EC = (EB) x (100 - (97.5 x .9)) / 100
= (48 x 106 organisms per day) x (100 - (97.5 x .9)) / 100
= 5.88 x 106 organisms per day.

    The Director may require additional monitoring necessary to
demonstrate compliance with Sec.  125.94(d), endangered species
requirements under Sec.  125.94(g), interim standards under Sec.
125.94(h), and any more stringent standards under Sec.  125.94(i).
    In addition, all facilities will either conduct visual inspections
or employ remote monitoring devices when the cooling water intake
structure is in operation. The facility will conduct such inspections
at least weekly to ensure that any technologies installed to comply
with Sec.  125.94 are maintained and operated to ensure that they will
continue to function as designed. EPA is aware that for some
facilities, this requirement could pose a feasibility challenge (for
example due to ice cover in the winter season, inability of divers to
see through more than a few inches of water, or certain intakes in deep
water). The rule, therefore, authorizes the Director to establish
alternative procedures. See Sec.  125.96(e).

H. What reports am I required to submit?

1. Status Reports
    If the Director establishes a compliance schedule, the Director
will also establish any status reporting requirements. These reports
may include updates on biological monitoring, technology testing
results, construction schedules, or other appropriate topics and serve
as milestones for the facility and the Director to evaluate the
progress of the facility in meeting BTA. See Sec. Sec.  125.94(b) and
(d) and 125.97(b).
2. Monitoring Reports
    The required reports for monitoring activities are similar to
requirements that are already in NPDES permits for effluent discharges.
EPA expects such reports to be included with the Discharge Monitoring
Reports (DMRs) or equivalent state reports. Facilities would report any
monitoring, demonstration, and other information required by the permit
sufficient to determine compliance with the permit requirements
established under Sec.  125.94, as well as any other monitoring
requirements specified in the permit. See 40 CFR 125.97(a).
    Entrainment requirements will be determined on a site-specific
basis by the Director. For facilities that are required to install
entrainment controls, EPA expects that these facilities would generally
conduct ongoing flow (or other) monitoring as verification that
entrainment has been reduced. See Sec.  125.96(b) and (c). However, the
Director may require facilities to report entrainment monitoring and
analysis, including:
     The compliance measurement location.
     A description of the flow monitoring procedure.
     Documentation of flow reductions.
     Any other monitoring requirements specified in the permit.
    The report must include any monitoring and analysis required as
part of additional measures for threatened and endangered species,
shellfish, or fragile species as established by the Director. Further,
your report will include documentation of cooling water that is process
water, gray water, waste water, reclaimed water, or other water reused
as cooling water in lieu of water obtained by an intake. The Director
will evaluate these reports for compliance with permit requirements as
appropriate.
3. Annual Certifications
    Today's rule requires a facility to submit an annual certification
statement signed by the responsible corporate officer. See Sec.
125.97(c). In most cases, the statement would indicate the information
from the previous statement is still pertinent. If modifications were
made to the facility that impacts cooling water withdrawals or
operation of the cooling water intake structures, the statement would
indicate such, and the facility would submit revisions to the
information required in their permit application at Sec.  122.21(r).
4. Other Reporting
    In addition, EPA notes that supplemental reporting may be required
under the ESA as part of any incidental take statement or permit (50
CFR 402.14(i)) or a section 10 permit (50 CFR 222.307) that is issued
by the United States Fish and Wildlife Service or the National Marine
Fisheries Service to ensure compliance with the Endangered Species Act.

I. What records will I be required to keep?

    As described at Sec.  125.97(d), facilities are required to keep
all permit applications, status, monitoring, and annual reports and
related supporting information and materials at least until the
subsequent permit is issued. Facilities might wish to keep records for
a longer period to maintain a complete regulatory history of the
facility. For example, existing source water biological studies
submitted with a facility's permit application could contain data that
has been collected in the past 10 or more years. When the Director has
approved a request for reduced information collection in the permit
application, the rule requires that records of submissions that are
part of a previous permit application be kept until the subsequent
permit is issued. See Sec.  125.95(e). Records supporting the BTA
determination for entrainment must be kept until such time as the
Director revises the determination. The Director may establish
additional record-keeping requirements in the permit, such as
additional records documenting compliance monitoring, data collection,
or more frequent reports.
    Facilities must also keep records of all data used to complete the
permit application and show compliance with the requirements of Sec.
125.94, any supplemental information developed under Sec.  125.95, and
any compliance monitoring data submitted under Sec.  125.96. The
Director may require that these records be kept for a longer period.

J. What are the respective Federal, State, and Tribal roles?

    Today's final rule affects authorized State and Tribal NPDES permit
programs. Under 40 CFR 123.62(e), any existing approved section 402
permitting program must be revised to be consistent with new program
requirements within one year from the date of this promulgation, unless
the NPDES-authorized State or Tribe must amend or enact a statute to
make the required revisions. If a State or Tribe must amend or enact a
statute to conform to today's final rule, the revision must be made
within two years of this promulgation. States and Tribes seeking new
EPA authorization to implement the NPDES program must comply with the
requirements when authorization is approved. This final regulation does
not alter State authority under section 510 of the CWA.
    In addition to updating their programs to be consistent with
today's final rule,

States and Tribes authorized to implement the NPDES program are
required under NPDES State program requirements to implement the
cooling water intake structure requirements of subpart J following
promulgation of the final regulations. The permit requirements in this
final rule must be implemented upon the first issuance or reissuance of
permits following promulgation. Duties of an authorized State or Tribe
under this regulation are described throughout this section and include
reviewing permit application materials, determining appropriate
requirements, reviewing monitoring and reporting data, and assessing
whether a facility is complying with the final rule's requirements.
    EPA recognizes that some States have invested considerable effort
in developing and implementing section 316(b) permits. This final
regulation at Sec.  125.98(b) and (g) allows the Director flexibility
where there are ongoing permit proceedings or where a BTA determination
has already been made based on substantially the same information
required at Sec.  122.21(r).
    EPA will implement these requirements where States or Tribes are
not authorized to implement the NPDES program.

K. Protection of Endangered and Threatened Species and Designated
Critical Habitat

1. Existing Requirements Under Section 9 of the Endangered Species Act
    The ESA imposes duties not just on Federal agencies but also on
other entities. Section 9 of the ESA specifically provides that it is
unlawful for any person to ``take'' any endangered species of fish or
wildlife except under defined circumstances. The Services (National
Marine Fisheries Service or U.S. Fish and Wildlife Service) may provide
an exemption to the prohibition on take in one of two ways. Take may be
permitted under section 10 of the ESA (16 U.S.C. 1539) or the Services
may provide an exemption for take that is incidental to otherwise legal
activity through a statement that is included with the Services'
biological opinion developed during Federal agency consultation. (16
U.S.C. 1536(o)) The incidental take statement specifies the terms and
conditions necessary to implement reasonable and prudent measures which
minimize incidental take.
    Nothing in today's rule changes the existing, independent
obligations of the facilities subject to this rule under section 9 of
the ESA. Unless exempted by an incidental take statement or section 10
permit, facilities have been prohibited from taking (for example,
harming or killing) endangered species of fish or wildlife. In order to
obtain a section 10 permit, the facility would be required to develop a
Habitat Conservation Plan (HCP), which is a mandatory component of an
incidental take permit application. The HCP must specify the
anticipated effects of the proposed taking, how those impacts will be
minimized or mitigated, the alternative actions to the taking that the
applicant considered, the reasons for not utilizing those alternatives,
and other necessary or appropriate measures that the Secretary may
require.
2. EPA's Consultation Under Section 7 of the ESA
    Under section 7 of the Endangered Species Act, each Federal agency
must insure that any action authorized, funded, or carried out by the
agency ``is not likely to jeopardize the continued existence of any
endangered species or threatened species or result in the destruction
or adverse modification of habitat of such species which is determined
by the Secretary, after consultation as appropriate with affected
States, to be critical. . . .'' 16 U.S.C. 1535(a)(2). In the case of
any Federal agency action subject to the ESA that may affect listed
species or critical habitat, the Federal agency must consult with the
concerned offices with responsibilities under the ESA, specifically
NMFS and/or FWS. 50 CFR 402.14(a).
    In July 2012, EPA began informal consultation with the NMFS about
the proposed section 316(b) regulations. In October 2012, EPA began
informal consultation with the FWS. EPA prepared a draft biological
evaluation of the effects of this rule on threatened and endangered
species and in it concluded that the rule was not likely to adversely
affect listed species or designated critical habitat. EPA was unable to
obtain the Services' concurrence on EPA's ``not likely to adversely
affect'' finding. In June 2013, EPA requested formal consultation with
the Services under the Endangered Species Act and with that request
submitted a final biological evaluation to the Services. EPA completed
consultations with the Services and has included the Services'
biological opinion and associated documents in the record for this
rulemaking.
    Among the organisms potentially subject to impingement and
entrainment at cooling water intake structures are those that are
listed as threatened and endangered. In addition to impinging or
entraining threatened and endangered species, operation of CWISs may
also adversely affect their critical habitat. Today's rule includes a
number of provisions specifically designed to address incidental take
of all federally-listed threatened and endangered species and to insure
that the rule is not likely to jeopardize the continued existence of
listed species or result in the destruction or adverse modification of
critical habitat. These provisions are described below.
    The regulatory model adopted by EPA in the Phase I rule and later
in the subsequently-withdrawn Phase II rule for large existing power
producing facilities provided a structure to address and minimize
adverse impacts to threatened and endangered species. EPA's approach
required that facilities subject to the 316(b) rules, at the permit
application stage of the permitting process must, among other things,
identify threatened and endangered species that might be subject to
impingement and entrainment in order to ensure that the permitting
authority would have the requisite information on which to make a
decision about the need for controls to protect threatened and
endangered species. See 40 CFR 122.21(r)(4).
    The Phase I and Phase II regulations specifically authorized the
permit writer (referred to as the ``Director'' in EPA's permitting
regulations) to adopt measures designed to protect threatened and
endangered species. Thus, for example, EPA's Phase I regulations for
cooling water intake structures at new facilities require that, under
one of the compliance options, an owner or operator must select and
implement impingement and entrainment minimization measures ``if there
are threatened or endangered or otherwise protected Federal, State or
Tribal species.'' Moreover, the permit writer may require additional
impingement and entrainment reduction measures if the permit writer
determines that the facility after meeting the required performance
standard would ``still contribute unacceptable stress to the protected
species, critical habitat of those species or species of concern.'' 40
CFR 125.84(b)(4) & (5).
    The Phase II regulation continued the general approach followed in
the Phase I regulation for protection of threatened and endangered
species. Permit applicants needed to submit the same information on
threatened and endangered species required in the Phase I rule. In
addition, building on the earlier information requirements, the
regulation also would have required facilities selecting and
implementing certain of the alternative BTA

compliance measures to submit a Comprehensive Demonstration Study that,
among other things, characterized impingement and entrainment at the
facility. Further, the rule would have required a facility to submit an
Impingement Mortality and/or Entrainment Characterization Study that
included taxonomic identification, characterization and documentation
of current impingement mortality and entrainment of all life stages of
fish, shellfish and any species protected under Federal, State or
Tribal law (including threatened or endangered species). 69 FR 41687-
88, July 9, 2004. In addition, the Phase I and II rules included a
requirement for the facility to include in their permit application
documentation of any public participation or consultation with Federal
or State agencies on impacts of their cooling water intake structure on
threatened and endangered species. The regulation then would have
required the permit writer to determine appropriate permit requirements
and conditions. EPA noted that its existing NPDES permitting
regulations reference a number of Federal laws that might apply to
Federally-issued NPDES permits, including the Endangered Species Act.
69 FR 41643-44, July 9, 2004.
    Threatened and endangered species were important considerations in
the proposal to today's rule and were of particular concern to the EPA.
The preamble to the proposal reflects at a number of points that, in
looking at the benefits of different regulatory options, EPA attempted
to assess the benefits to threatened and endangered species. See 76 FR
22174, 22197, 22207. The proposal also noted the importance of
obtaining information for the permit writer about potential entrainment
reductions. Thus, the proposal would have required certain facilities
to develop and submit with their permit application detailed
information on their operations as well as an engineering study of the
technical feasibility and incremental costs of candidate entrainment
mortality control technologies and a detailed discussion of the
magnitude of non-water quality benefits. EPA proposed that some
facilities would need to submit an Entrainment Characterization Study
that included an entrainment mortality data collection plan that would
indicate, at a minimum, taxonomic identification, latent mortality
identification, documentation of all methods, and quality assurance/
quality control procedures or sampling and data analysis appropriate
for a quantitative survey. Under the proposal, EPA would also have
required peer review of the entrainment mortality data collection plan.
Peer reviewers would be selected in consultation with the Director who
may consult with EPA and Federal, State, and Tribal fish and wildlife
management agencies with responsibility for fish and wildlife
potentially affected by the cooling water intake structure(s). Further,
facilities with greater than 125 mgd AIF would complete an entrainment
study. The entrainment study could include information already
collected to meet the Phase II requirements at Sec.  122.21(r)(2)-
(r)(4) before those requirements were suspended.
    EPA and the Services have completed consultations on the rule. EPA
has received the final biological opinion and associated documents from
the U.S. Fish and Wildlife Service and the U.S. National Marine
Fisheries Service and has included them in the record for the rule. The
Services have concluded that the rule is not likely to jeopardize the
continued existence of listed species or result in the destruction or
adverse modification of designated critical habitat.
3. Final Rule Provisions Related to Threatened and Endangered Species
    As noted previously, establishing standards for cooling water
intake structures to minimize impingement and entrainment of all
aquatic organisms will promote and enhance protection of T&E species.
In addition, the rule contains a number of provisions that specifically
concern T&E species; these provisions were developed in light of EPA's
consultation with the Services and were established by EPA to insure
that this rule is not likely to jeopardize listed species or result in
the destruction or adverse modification of designated critical habitat.
To be clear, the ESA provisions of the rule extend to all listed T&E
species, not just fish and shellfish.
    The treatment of T&E species in today's rule follows directly from
the Agency's longstanding approach as well as from EPA's proposed 2011
rule which indicated the EPA's intention to address protection of T&E
species. The rule adopts the identical approach followed in the Phase I
and II rules, while adding some refinements to that earlier model which
EPA discussed in the proposed rule. First, it adopts the proposed
requirements that insure an adequate information base is submitted to
the permit writer. As was the case with the Phase I and withdrawn Phase
II rule, apprising the permit writer of the presence and extent of T&E
species at a facility's intake continues to be an important element of
the permit application requirements for existing facilities. While
retaining the existing permit application requirement of 40 CFR
122.21(r), EPA has included in today's rule a provision at Sec.
125.95(f) that requires a facility in its permit application to
identify all Federally-listed threatened and endangered species and
designated critical habitat that are or may be present in the action
area. The action area can generally be considered the area in the
vicinity of the cooling water intake structure. The evaluation is to be
based on information readily available to the facility at the time of
the permit application. In addition, the rule requires the largest
withdrawing facilities to provide taxonomic identification of species
in the vicinity of the intake, thus providing a mechanism for
facilities to determine more accurately their potential impact on
protected species.
    The rule requires that the Director transmit all permit
applications to the Services upon receipt. The rule provides the
Services with 60 days to review the permit application. This 60 day
review takes place prior to the public notice of the State or Tribe's
draft or proposed permit. EPA expects that the Services will respond
within 60 days and provide to the Director (1) any corrections to the
list of Federally-listed threatened and endangered species and critical
habitat included in the permit application, (2) any measures that the
Services recommend (including monitoring and reporting) for the
protection of listed species, including any measures that would
minimize any incidental take of listed species, and/or avoid likely
jeopardy to a listed species or destruction or adverse modification of
critical habitat, and/or (3) notify the State or Tribe that the
Service(s) have no corrections to the list of species and critical
habitat and/or that the Service(s) do not recommend any control
measures. The Services' 60 day review period does not constrain the
Director's ability to process the applicant's permit application;
however, the Director may not propose/publish the draft permit until
the 60 day review period has ended, unless the Director has received
the Services' response prior to that time.
    In addition, the Services will receive, pursuant to existing
regulations at 40 CFR 124.10(c)(1)(iii) and (e), all permit
applications, as well as fact sheets or statements of basis (for EPA-
issued permits), draft permits, and public notices for all permits. At
this stage of the process, the Services will have the opportunity to
review the draft permit and other materials and provide any

additional input or suggested control measures to address effects to
listed species or critical habitat. Together, the existing and new
requirements related to transmittal of permitting documents to the
Services will ensure that the Services have the opportunity to provide
information and recommendations to the permit writer relating to any
facility that may affect listed species. This information will be part
of the public record for the permitting decision and the Director would
be required to consider it as a relevant factor, along with all of the
other relevant factors, in deciding what conditions to establish in the
permit. Further, as explained in the MOA between EPA and the Services
discussed elsewhere in today's notice, EPA will use the full extent of
its CWA authority to object to a permit where EPA finds that issuance
of the permit is likely to jeopardize the continued existence of a
listed species or result in the destruction or adverse modification of
designated critical habitat. The rule's requirements insure a full
vetting of information and concerns in the permitting process that must
be considered by the Director. These requirements, coupled with the
EPA's commitment to exercise its oversight authority, insure that
today's rule is not likely to jeopardize the continued existence of a
listed species or result in the destruction or adverse modification of
designated critical habitat.
    Among the recommendations that may be made by the Services to the
facility and the Director are measures to minimize incidental take. EPA
expects that any measures the Services recommend to minimize incidental
take will be consistent with ESA regulations and guidances concerning
reasonable and prudent measures. As stated in the ESA regulations under
50 CFR 402.14(i)(2), ``Reasonable and prudent measures, along with the
terms and conditions that implement them, cannot alter the basic
design, location, scope, duration, or timing of the action and may
involve only minor changes.'' The Endangered Species Handbook (FWS and
NMFS, 1998) explains that: ``Measures are considered reasonable and
prudent when they are consistent with the proposed action's basic
design (e.g., narrowing of disturbed right-of-way at known species
locations), location (e.g., temporary storage of equipment or other
materials), scope, duration, and timing. Reasonable and prudent
measures and terms and conditions should be developed in coordination
with the action agency and applicant, if any, to ensure that the
measures are reasonable, that they cause only minor changes to the
project, and that they are within the legal authority and jurisdiction
of the agency or applicant to carry out.''
    Installation of closed-cycle cooling is a major design alteration
of a facility involving significant design and construction activities
(the range of costs associated with closed-cycle cooling is described
elsewhere in today's notice). Because installation of closed-cycle
cooling does alter the basic design of a facility and would involve
more than minor changes, as described in the Services' regulations and
Handbook, EPA does not expect that installation of closed-cycle cooling
would be specified as a measure solely for purposes of minimizing
incidental take. The final rule at Sec.  125.98(j) provides that
nothing in this rule authorizes the take of threatened or endangered
species of fish or wildlife. However, the Services may exempt take
through an incidental take statement issued pursuant to ESA section
7(o) or a permit under ESA section 10. See 16 U.S.C. 1536 (o) and 16
U.S.C. 1539.
    This Clean Water Act rule cannot authorize take and does not
purport to do so (nor can NPDES permits authorize take prohibited under
the ESA). Accordingly, under Sec.  125.98(b)(1), the permit writer,
including EPA, must include, in the 316(b) permit requirements,
standard language that states the permit does not authorize the take of
Federally-listed threatened and endangered species. In addition, under
Sec.  125.96(g) (additional monitoring requirements) and Sec.
125.97(g) (additional reporting requirements),where the Director
requires additional measures to protect listed species, monitoring and
reporting requirements associated with those measures will be included
in the permit.