commonly found in steam electric power plant wastewater discharges
include mercury, lead, arsenic, cadmium, thallium, and selenium, along
with numerous others (see EA Section 3). These pollutants are
associated with a variety of documented adverse human health impacts.
For example, human exposure to elevated levels of mercury for
relatively short periods of time can result in kidney and brain damage.
Pregnant women who are exposed to mercury can pass the contaminant to
their developing fetus, leading to possible toxic injury of the fetal
brain and damage to other parts of the nervous system. Human exposure
to elevated levels of lead can cause serious damage to the brain,
kidneys, nervous system, and red blood cells, especially in children.
Arsenic is associated with an increased risk of liver and bladder
cancer in humans, as well as non-cancer impacts including dermal,
cardiovascular, respiratory, and reproductive effects such as excess
incidences of miscarriages, stillbirths, preterm births, and low birth
weights. Chronic exposure to cadmium, a probable carcinogen, can lead
to kidney failure, lung damage, and weakened bones. Human exposure to
elevated levels of thallium can lead to neurological symptoms, hair
loss, gastrointestinal effects, liver and kidney damage, and
reproductive and developmental damage. Long-term exposure to selenium
can damage the kidney, liver, and nervous and circulatory systems.
    The pollutants in steam electric power plant wastewater can
bioaccumulate within fish and other aquatic wildlife in the receiving
waters and subsequently be transferred to recreational and subsistence
fishers who consume these contaminated fish, potentially resulting in
the acute and chronic health impacts described above. Certain
populations are particularly at risk, including women who are pregnant,
nursing, or may become pregnant, and communities relying on consumption
of fish from contaminated waters as a major food source.
    Discharges of steam electric power plant pollutants to surface
waters also have the potential to contaminate drinking water sources,
causing potential problems for drinking water systems and, if left
untreated, potential adverse health effects. A recent study indicates
that pollutants in ash and FGD wastewater discharges exceeded MCLs in
every surface water that was monitored in North Carolina during the
study (see DCN SE01984). Nitrogen discharges from steam electric power
plants can contribute, along with other sources, to harmful algal
blooms. Harmful algal blooms can affect drinking water sources, such as
the recent incident in Toledo, Ohio (see DCN SE04517).
    Bromide discharges from steam electric power plants can contribute
to the formation of carcinogenic DBPs in public drinking water systems.
A recent study identified four drinking water treatment plants that
experienced increased levels of bromide in their source water, and in
some, a corresponding increase in the formation of brominated DBPs in
the drinking water system, after the installation of wet FGD scrubbers
at upstream steam electric power plants (see DCN SE04503).
    Although not directly addressed by this final rule, ground water
contamination from surface impoundments containing steam electric power
plant wastewater also threatens drinking water sources. EPA identified
more than 30 documented cases where ground water contamination from
surface impoundments extended beyond the plant boundaries, illustrating
the threat to ground water drinking water sources (see DCN SE04518).
Where this final rule helps to reduce or eliminate the continued
disposal or storage of steam electric power plant wastewater pollutants
in unlined or leaking surface impoundments, potential impacts to ground
water will also be reduced or eliminated.
    The ecological impacts of steam electric power plant wastewater
pollutants include both acute (e.g., fish kills) and chronic effects
(e.g., reproductive failure, malformations, and metabolic, hormonal,
and behavioral disorders) upon biota within the receiving water and the
surrounding environment. Recovery of aquatic environments from exposure
to these steam electric power plant pollutants can be extremely slow
due to the accumulation and continued cycling of the pollutants within
ecosystems, resulting in the potential to alter ecological processes
such as population diversity and community dynamics. Furthermore, many
steam electric power plants discharge pollutants to sensitive
environments such as the Great Lakes, valuable estuaries such as the
Chesapeake Bay, 303(d) listed impaired waters, and waters with fish
consumption advisories. EPA identified 69 steam electric power plants
with documented adverse environmental impacts on surface waters (see
DCN SE04518).

C. Environmental Assessment Methodology

    As discussed in Section V.G, EPA updated the environmental
assessment for the final rule to respond to public comments and to
better characterize the environmental and human health improvements
associated with the final rule. Although not required to do so, EPA
conducted an environmental assessment for the final rule. The
environmental assessment reviewed currently available literature on the
documented environmental and human health impacts of steam electric
power plant wastewater discharges and conducted modeling to determine
the cumulative impacts of pollution from the universe of steam electric
power plants to which the final rule applies. EPA modeled both of the
impacts of steam electric power plant discharges at baseline conditions
and the improvements that will likely result after implementation of
this rule. The final environmental assessment also incorporates changes
to the industry profile to account for retirements, conversions, and
operational changes

that EPA anticipates, given other existing rules, primarily the CCR and
CPP rules.
    The environmental assessment modeling for the final rule consisted
of (1) a steady-state, national-scale immediate receiving water (IRW)
model that evaluated the discharges from steam electric power plants
and focused on impacts within the immediate surface water where the
discharges occur (approximately one to 10 kilometers [km] from the
outfall),\51\ and (2) dynamic case study models with more extensive,
site-specific modeling of selected waterbodies that receive, or are
downstream from, steam electric power plant discharges. EPA also
modeled receiving water concentrations downstream from steam electric
power plant discharges using EPA's Risk-Screening Environmental
Indicators (RSEI) model, and improved its modeling of selenium
bioaccumulation in fish and wildlife.
---------------------------------------------------------------------------

    \51\ The IRW model used for the final rule is substantially
similar to the one used for the proposed rule, but with certain
updates, as further discussed in this section.
---------------------------------------------------------------------------

    Additionally, for the final rule, EPA updated and improved several
input parameters for the IRW model, including fish consumption rates
for recreational and subsistence fishers, the bioconcentration factor
for copper, and benchmarks for assessing the potential for impacts to
benthic communities in receiving waters.
    The case-study modeling for the final rule is based on EPA's Water
Quality Analysis Simulation Program (WASP), which accounts for
fluctuations in receiving water flow rates by using daily stream flow
monitoring data instead of one annual average flow rate for the
receiving water, as used in the IRW. The case-study modeling accounts
for pollutant transport and accumulation within receiving water reaches
that are downstream from the discharge location, allowing for an
assessment of environmental impacts over a larger portion of the
receiving waterbody. The case study modeling also accounts for
pollutant contributions from other point, nonpoint, and background
sources, to the extent practical, using available data sources. EPA
used the water quality results of the case-study modeling to supplement
the results of the IRW model (see EA Section 8).
    EPA improved its selenium bioaccumulation modeling for impacts on
wildlife by developing and using an ecological risk model that predicts
the risk of reproductive impacts among fish and waterfowl exposed to
selenium from steam electric power plant wastewater discharges. The
ecological risk model accounts for the bioaccumulation of selenium in
aquatic organisms through dietary exposure (the food web), as
contrasted with exposure only to dissolved selenium in the water
column. Dietary exposure plays a more significant role in determining
the extent of selenium bioaccumulation in aquatic organisms. The
ecological risk model also accounts for the higher rates of selenium
bioaccumulation that can occur in slow-flowing aquatic systems such as
lakes and reservoirs, and the risk model translates selenium tissue
concentrations into the predicted risk of adverse reproductive effects
(e.g., reduced egg hatchability, larval mortality, and deformities that
affect survival) among exposed fish and waterfowl. EPA applied the
ecological risk model to the water quality outputs from both the
national-scale IRW model and the case-study models. See EA Section 5.2
for a more detailed discussion.

D. Outputs From the Environmental Assessment

    EPA focused its quantitative analyses on the environmental and
human health impacts associated with exposure to toxic bioaccumulative
pollutants via the surface water pathway. EPA focused the modeling on
discharges of toxic bioaccumulative pollutants from a subset of
evaluated wastestreams from steam electric power plants (fly ash and
bottom ash transport water, FGD wastewater, and combustion residual
leachate) into rivers/streams and lakes/ponds (including
reservoirs).\52\ EPA addressed environmental impacts from nutrients in
a separate analysis discussed in Section XIII.D.5.
---------------------------------------------------------------------------

    \52\ EPA did not use the state 303d lists of impaired waters in
order to ensure comprehensive coverage of all pollutants of concern.
---------------------------------------------------------------------------

    The environmental assessment concentrates on impacts to aquatic
life based on changes in surface water quality; impacts to aquatic life
based on changes in sediment quality within surface waters; impacts to
wildlife from consumption of contaminated aquatic organisms; and
impacts to human health from consumption of contaminated fish and
water. Table XIII-1 presents a list of the key environmental
improvements projected within the immediate receiving waters due to the
pollutant loading reductions under the final rule. These improvements
are discussed in detail, with quantified results, in the EA.

  Table XIII-1--Key Environmental Improvements Within Modeled Immediate
                Receiving Waters Under the Final Rule 53
------------------------------------------------------------------------
                                            Will improve under the final
    Criteria evaluated for exceedances                  rule?
------------------------------------------------------------------------
Freshwater Acute National Recommended WQC.  YES
Freshwater Chronic National Recommended     YES
 WQC.
Human Health Water and Organism National    YES
 Recommended WQC.
Human Health Organism Only National         YES
 Recommended WQC.
Drinking Water MCL........................  YES
Fish Ingestion NEHC for Mink..............  YES
Fish Ingestion NEHC for Eagles............  YES
Adverse Reproductive Effects in Fish due    YES
 to Selenium.
Adverse Reproductive Effects in Mallards    YES
 due to Selenium.
Non-Cancer Reference Dose for Child         YES
 (Recreational and Subsistence fishers).
Non-Cancer Reference Dose for Adult         YES
 (Recreational and Subsistence fishers).
Arsenic Cancer Risk for Child               YES
 (Recreational and Subsistence fishers).
Arsenic Cancer Risk for Adult               YES
 (Recreational and Subsistence fishers).
------------------------------------------------------------------------
Acronyms: MCL (Maximum Contaminant Level); NEHC (No Effect Hazard
  Concentration); WQC (Water Quality Criteria).
\a\ The IRW model encompasses a total of 163 immediate receiving waters
  (144 rivers and streams; 19 lakes, ponds, and reservoirs) and loadings
  from 143 steam electric power plants.

1. Improvements in Surface Water and Ground Water Quality
---------------------------------------------------------------------------

    \53\ See the EA for the details and amounts of the projected
improvements.
---------------------------------------------------------------------------

    EPA estimates a significant number of environmental and ecological
improvements and reduced impacts to wildlife and humans from reductions
in pollutant loadings under the final rule. More specifically, the
environmental assessment evaluated (a) improvements in water quality,
(b) reduction in impacts to wildlife, (c) reduction in number of
receiving waters with potential human health cancer risks, (d)
reduction in number of receiving waters with potential to cause non-
cancer human health effects, (e) reduction in nutrient impacts, (f)
reduction in other environmental impacts, and (g) other unquantified
environmental improvements.

    EPA expects significantly reduced contamination levels in surface
waters and sediments under the final rule. EPA estimates that reduced
pollutant loadings to surface waters will significantly improve water
quality by reducing pollutant concentrations by an average of 56
percent within the immediate receiving waters of steam electric power
plants where additional treatment technologies are installed as a
result of this final rule. Based on the water quality component of the
IRW model, which compares modeled receiving water concentrations to
national recommended WQC and MCLs to assess changes in receiving water
quality, the pollutants with the greatest number of water quality
standard exceedances under baseline pollutant loadings include: Total
arsenic, total thallium, total selenium, and dissolved cadmium. EPA
estimates that almost half of the immediate receiving waters exceed a
water quality standard under baseline loadings. EPA estimates that the
number of immediate receiving waters with aquatic life exceedances,
which are driven by high total selenium and dissolved cadmium
concentrations, will be reduced under the final rule. EPA also
estimates that the number of immediate receiving waters with human
health water quality standards exceedances, primarily driven by high
total arsenic and total thallium concentrations, will be reduced under
the final rule.
    Selenium is one of the primary pollutants documented in the
literature as causing environmental impacts to fish and wildlife. EPA
calculates that total selenium receiving water concentrations will be
reduced by two-thirds under the final rule, leading to a reduction in
the number of immediate receiving waters exceeding the freshwater
chronic criteria for selenium.
    While the case-study models and IRW model produced generally
similar results for the five receiving waters included in both
analyses, the case-study model reveals additional potential for
baseline impacts to water quality, aquatic life, and human health that
are not reflected in the IRW model. Case-study modeling also reveals
that these potential impacts can extend beyond the immediate receiving
water and into downstream waters, leading to the potential for more
widespread environmental and human health effects than those shown with
the IRW model. This is particularly true regarding water quality
standard exceedances; in four of the five receiving waters included in
both analyses, the case-study model indicates that the final rule will
result in further reductions in water quality standard exceedances
beyond those reflected in the IRW model.
    As discussed in the EA, the RSEI modeling indicates that surface
waters downstream from steam electric power plant wastewater discharges
will also achieve water quality improvements under the final rule.
    This final rule will also potentially help to both reduce ground
water contamination and improve the availability of ground water
resources by complementing the CCR rule. This rule provides strong
incentives for plants to greatly reduce, if not entirely eliminate,
disposal and treatment of steam electric power plant wastewater in
unlined surface impoundments.
2. Reduced Impacts to Wildlife
    EPA expects that once the rule is implemented the number of
immediate receiving waterbodies with potential impacts to wildlife will
begin to be reduced by more than a half compared to baseline conditions
under the final rule.
    EPA determined that steam electric power plant wastewater
discharges into lakes pose the greatest risk to piscivorous (fish
eating) wildlife, with almost a half of lakes exceeding a protective
benchmark for minks or eagles under baseline pollutant loadings
(compared to about a third of rivers). Mercury and selenium are the
primary pollutants with the greatest number of receiving waters with
benchmark exceedances. EPA estimates that this rule will reduce the
number of immediate receiving waters exceeding the benchmark for minks
and eagles by approximately half for mercury and selenium.
Additionally, as discussed in the EA, the downstream RSEI modeling
indicates that surface waters downstream from steam electric power
plant wastewater discharges will also achieve improvements in these
wildlife benchmarks under the final rule.
    For the final rule, EPA also performed modeling to estimate the
risk of adverse reproductive effects among fish (e.g., reduced larvae
survival) and waterfowl (e.g., reduced egg hatchability) with dietary
exposure to selenium from steam electric power plant wastewater. Based
on the water quality output from the IRW model, EPA determined that
approximately 15 percent of immediate receiving waters contain selenium
concentrations that present at least a ten percent risk of adverse
reproductive effects among fish or waterfowl that consume prey from
those waterbodies. Under the final rule, EPA estimates that the count
of immediate receiving waters presenting these reproductive risks will
be reduced by more than half. This indicates that the final rule will
reduce the long-term bioaccumulative impact of selenium (and possibly
other bioaccumulative pollutants) throughout aquatic ecosystems.
    In addition, EPA estimates that the improvements to water quality,
discussed above, will improve aquatic and wildlife habitats in the
immediate and downstream receiving waters from steam electric power
plant discharges. EPA determined that these water quality and habitat
improvements will enhance efforts to protect threatened and endangered
species. EPA identified four species with a high vulnerability to
changes in water quality whose recovery will be enhanced by the
pollutant reductions associated with the final rule.
3. Reduced Human Health Cancer Risk
    EPA estimates that reductions in arsenic loadings from the final
rule will result in a reduction in potential cancer risks to humans
that consume fish exposed to steam electric power plant discharges. In
addition, based on the downstream RSEI modeling, EPA estimates that
numerous river miles downstream from steam electric discharges contain
fish contaminated with inorganic arsenic that present cancer risks to
at least one of the evaluated cohorts. The final rule substantially
reduces this number of miles.
4. Reduced Threat of Non-Cancer Human Health Effects
    Exposure to toxic bioaccumulative pollutants poses risk of systemic
and other effects to humans, including effects on the circulatory,
respiratory, or digestive systems, and neurological and developmental
effects. EPA estimates the final rule will significantly reduce the
number of receiving waters with the potential to cause non-cancer
health effects in humans who consume fish exposed to steam electric
power plant pollutants.
    Under baseline pollutant loadings, EPA determined that about half
of immediate receiving waters present non-cancer health risks for one
or more of the human cohorts due to elevated pollutant levels in fish.
The final rule, once implemented, will begin to reduce this amount by
approximately 50 percent for all the human cohorts that were evaluated.
Non-cancer risks are caused primarily by mercury (as methylmercury),
total thallium, and total selenium, and to a lesser degree, total
cadmium pollutant loadings. Additionally, as discussed in the EA, the
downstream RSEI modeling indicates that the final rule substantially

reduces the prevalence of downstream waters with contaminated fish that
present non-cancer health risks to at least one of the human cohorts.
    In addition to the assessment of non-cancer impacts described
above, EPA also evaluated the adverse health effects to children who
consume fish contaminated with lead from steam electric power plant
wastewater. EPA estimates that the final rule will significantly reduce
the associated IQ loss among children who live in recreational angler
and subsistence fisher households. The final rule will also reduce the
incidence of other health effects associated with lead exposure among
children, including slowed or delayed growth, delinquent and anti-
social behavior, metabolic effects, impaired heme synthesis, anemia,
and impaired hearing. The final rule will also reduce IQ loss among
children exposed in utero to mercury from maternal fish consumption.
Section XIV.B.1 provides additional details on the benefits analysis of
these reduced IQ losses.
    The final rule will also result in additional non-cancer human
health improvements beyond those discussed above, including reduced
health hazards due to exposure to contaminants in waters that are used
for recreational purposes (e.g., swimming).
5. Reduced Nutrient Impacts
    The primary concern with nutrients (nitrogen and phosphorus) in
steam electric power plant discharges is the potential for contributing
to adverse impacts in waterbodies that receive nutrient discharges from
multiple sources. Excessive nutrient loadings to receiving waters can
significantly affect the ecological stability of freshwater and
saltwater aquatic ecosystems and pose health threats to humans from the
generation of toxins by cyanobacteria, which can thrive in nitrogen
driven algal blooms (DCN SE04505).
    Nine percent of surface waters receiving steam electric power plant
wastewater discharges are impaired for nutrients. Although the
concentration of nitrogen present in steam electric power plant
discharges from any individual power plant is relatively low, the total
nitrogen loadings from a single plant can be significant due to large
wastewater discharge flow rates.
    EPA projects that the final rule will reduce total nutrient
loadings by steam electric power plants in their immediately downstream
receiving waters by more than 99 percent. Section XIV provides
additional details on the water quality benefits analysis of nutrient
reductions, as determined using the SPARROW (Spatially Referenced
Regressions On Watershed attributes) model.

E. Unquantified Environmental and Human Health Improvements

    The environmental assessment focused primarily on the
quantification of environmental improvements within rivers and lakes
from post-compliance pollutant reductions for toxic bioaccumulative
pollutants and excessive nutrients. While extensive, the environmental
improvements quantified do not encompass the full range of improvements
anticipated to result from the final rule simply because some of the
improvements have no method for measuring a quantifiable or monetizable
improvement. EPA estimates post-compliance pollutant reductions from
the final rule to result in much greater improvements than those
quantified for wildlife, human health and the environment by:
     Reducing loadings of bioaccumulative pollutants to the
broader ecosystem, resulting in the reduction of long-term exposures
and sub-lethal ecological effects;
     Reducing sub-lethal chronic effects of toxic pollutants on
aquatic life not captured by the national recommended WQC;
     Reducing loadings of pollutants for which EPA did not
perform water quality modeling in support of the environmental
assessment (e.g., boron, manganese, aluminum, vanadium, and iron);
     Mitigating impacts to aquatic and aquatic-dependent
wildlife population diversity and community structures;
     Reducing exposure of wildlife to pollutants through direct
contact with combustion residual surface impoundments and constructed
wetlands built as treatment systems at steam electric power plants; and
     Reducing the potential for the formation of harmful algal
blooms.
    Data and analytical limitations prevent modeling the scale and
complexity of the ecosystem processes potentially impacted by steam
electric power plant wastewater, resulting in the inability to quantify
all potential improvements. However, documented site-specific impacts
in the literature reinforce that these impacts are common in the
environments surrounding steam electric power plants and fully support
the conclusion that reducing pollutant loadings will further reduce
risks to human health and wildlife and prevent damage to the
environment.
    Although the environmental assessment quantifies impacts to
wildlife that consume fish contaminated with pollutants from steam
electric power plant wastewater, it does not capture the full range of
exposure pathways through which bioaccumulative pollutants can enter
the surrounding food web. Wildlife can encounter toxic bioaccumulative
pollutants from discharges of the evaluated wastestreams through a
variety of exposure pathways such as direct exposure, drinking water,
consumption of contaminated vegetation, and consumption of contaminated
prey other than fish and invertebrates. Therefore, the quantified
improvements underestimate the complete loadings of bioaccumulative
pollutants that can impact wildlife in the ecosystem. The final rule
will lower the total amount of toxic bioaccumulative pollutants
entering the food web near steam electric power plants.
    EPA also estimates that reductions in pollutant loadings will lower
the occurrence of sub-lethal effects associated with many of the
pollutants in steam electric power plant wastewater that are not
captured by comparisons with national recommended WQC for aquatic life.
Chronic effects such as decreased reproductive success, changes in
metabolic rates, decreased growth rates, changes in morphology (e.g.,
fin erosion, oral deformities), and changes in behavior (e.g., swimming
ability, ability to catch prey, ability to escape from predators) that
can negatively affect long-term survival, are well documented in the
literature as occurring in aquatic environments near steam electric
power plants. Reductions in organism survival rates from chronic
effects such as abnormalities can alter interspecies relationships
(e.g., declines in the abundance or quality of prey) and prolong
ecosystem recovery. Additionally, EPA was unable to quantify changes to
aquatic and wildlife population diversity and community dynamics;
however, population effects (decline in number and type of organisms
present) caused by exposure to steam electric power plant wastewater
are well documented in the literature. Changes in aquatic populations
can alter the structure and function of aquatic communities and cause
cascading effects within the food web that result in long-term impacts
to ecosystem dynamics. EPA estimates that post-compliance pollutant
loading reductions associated with the final rule will lower the
stressors that can cause alterations in population and community
dynamics and improve the overall function of ecosystems

surrounding steam electric power plants, as well as help resolve issues
faced in other national ecosystem protection programs such as the Great
Lakes program, the National Estuaries program, and the 303(d) impaired
waters program.
    The post-compliance pollutant reductions associated with the final
rule will also decrease the environmental impacts to wildlife exposed
to pollutants through direct contact with surface impoundments and
constructed wetlands at steam electric power plants. Documented site-
specific impacts demonstrate that wildlife living in close proximity to
combustion residual impoundments exhibit elevated levels of arsenic,
cadmium, chromium, lead, mercury, selenium, and vanadium. Multiple
studies have linked these ``attractive nuisance'' areas (contaminated
impoundments at a steam electric power plant that attract wildlife for
nesting or feeding) to diminished reproductive success. EPA estimates
that the post-compliance pollutant reductions will decrease the
exposure of wildlife populations to toxic pollutants and reduce the
risks for impacts on reproductive success.

F. Other Improvements

    Other improvements will occur to other resources that are
associated directly or indirectly with the final rule. These include
aesthetic and recreational improvements, reduced economic impacts such
as clean up and treatment costs in response to contamination or
impoundment failures, reduced injury associated with pond failures,
reduced ground water contamination, support for threatened and
endangered species, reduced water usage and reduced air emissions.
Section XIV provides additional details on the monetized benefits of
these improvements.

XIV. Benefits Analysis

    This section summarizes EPA's estimates of the national
environmental benefits expected to result from reduction in steam
electric power plant wastewater discharges described in Section X and
the resultant environmental effects summarized in Section XIII. The BCA
Report provides additional details on benefits methodologies and
analyses, including uncertainties and limitations. The analysis
methodology is generally the same as that used by EPA for analysis of
the proposed rule, but with revised inputs and assumptions that reflect
updated data and address comments the Agency received on the proposed
rule, including additional categories of benefits the Agency analyzed
for the final rule.

A. Categories of Benefits Analyzed

    Table XIV-1 summarizes benefit categories associated with the final
rule and notes which categories EPA was able to quantify and monetize.
Analyzed benefits fall within five broad categories: Human health
benefits from surface water quality improvements, ecological conditions
and recreational use benefits from surface water quality improvements,
market and productivity benefits, air-related benefits (which include
both human health and climate change-related effects), and water
withdrawal benefits. Within these broad categories, EPA was able to
assess benefits with varying degrees of completeness and rigor. Where
possible, EPA quantified the expected effects and estimated monetary
values. However, data limitations and gaps in the understanding of how
society values certain water quality changes prevent EPA from
quantifying and/or monetizing some benefit categories.

                           TABLE XIV-1--Benefit Categories Associated With Final Rule
----------------------------------------------------------------------------------------------------------------
                                                                                Neither
                       Benefit category                         Quantified and   Quantified but   quantified nor
                                                                  monetized      not monetized      monetized
----------------------------------------------------------------------------------------------------------------
1. Human Health Benefits from Surface Water Quality Improvements
----------------------------------------------------------------------------------------------------------------
Reduced incidence of cancer from arsenic exposure via fish                  X
 consumption.................................................
Reduced incidence of cardiovascular disease from arsenic                                     X
 exposure via fish consumption...............................
Reduced incidence of cardiovascular disease from lead                   X \a\
 exposure via fish consumption...............................
Reduced incidence of other cancer and non-cancer adverse                                     X
 health effects (e.g., reproductive, immunological,
 neurological, circulatory, or respiratory toxicity) due to
 exposure to arsenic, lead, cadmium, and other toxics from
 fish consumption............................................
Reduced IQ loss in children from lead exposure via fish                     X
 consumption.................................................
Reduced need for specialized education for children from lead               X
 exposure via fish consumption...............................
Reduced in utero mercury exposure via maternal fish                         X
 consumption.................................................
Reduced health hazards from exposure to pollutants in waters                                                  X
 used recreationally (e.g., swimming)........................
----------------------------------------------------------------------------------------------------------------
2. Ecological Conditions and Recreational Use Benefits from Surface Water Quality Improvements
----------------------------------------------------------------------------------------------------------------
Benefits from improvements in surface water quality,                        X
 including: Improved aquatic and wildlife habitat; enhanced
 water-based recreation, including fishing, swimming,
 boating, and near-water activities; increased aesthetic
 benefits, such as enhancement of adjoining site amenities
 (e.g., residing, working, traveling, and owning property
 near the water \b\; and non-use value (existence, option,
 and bequest value from improved ecosystem health) \b\.......
Benefits from improved protection of threatened and                         X
 endangered species..........................................
Reduced sediment contamination...............................                                                 X
----------------------------------------------------------------------------------------------------------------
3. Market and Productivity Benefits
----------------------------------------------------------------------------------------------------------------
Reduced impoundment failures (monetized benefits include                    X                                 X
 avoided cleanup costs, transaction costs, and environmental
 damages; non-quantified benefits include avoided injury)....
Reduced water treatment costs for municipal drinking water,                                                   X
 irrigation water, and industrial process....................
Improved commercial fisheries yields.........................                                                 X
Increased tourism and participation in water-based recreation                                                 X
Increased property values from water quality improvements....                                                 X
Increased ability to market coal combustion byproducts.......           X \a\

Reduced maintenance dredging in navigational waterways and              X \a\
 reservoirs from reduction in sediment discharges............
----------------------------------------------------------------------------------------------------------------
4. Air-Related Benefits
----------------------------------------------------------------------------------------------------------------
Human health benefits from reduced morbidity and mortality                  X
 from exposure to NOX, SO2 and particulate matter (PM2.5)....
Avoided climate change impacts from CO2 emissions............               X
----------------------------------------------------------------------------------------------------------------
5. Benefits from Reduced Water Withdrawals
----------------------------------------------------------------------------------------------------------------
Increased availability of ground water resources.............               X
Reduced impingement and entrainment of aquatic organisms.....                                                 X
Reduced susceptibility to drought............................                                                 X
----------------------------------------------------------------------------------------------------------------
\a\ Monetized benefit category added for the final rule.
\b\ These values are implicit in the total willingness to pay (WTP) for water quality improvements.

    The following section summarizes EPA's analysis of the benefits
that the Agency was able to quantify and monetize (identified in the
second column of Table XIV-1). The final rule will also provide
additional benefits that the Agency was not able to monetize. The BCA
Report further describes some of these additional non-monetized
benefits.

B. Quantification and Monetization of Benefits

1. Human Health Benefits From Surface Water Quality Improvements
    Reduced pollutant discharges from steam electric power plants
generate human health benefits in a number of ways. As described in
Section XIII, exposure to pollutants in steam electric power plant
discharges via consumption of fish from affected waters can cause a
wide variety of adverse health effects, including cancer, kidney
damage, nervous system damage, fatigue, irritability, liver damage,
circulatory damage, vomiting, diarrhea, brain damage, IQ loss, and many
others. Because the final rule will reduce discharges of steam electric
pollutants into waterbodies that receive, or are downstream from, these
discharges, it is likely to result in decreased incidences of
associated illnesses.
    Due to data limitations and uncertainties, EPA is able to monetize
only a subset of the health benefits associated with reductions in
pollutant discharges from steam electric power plants. EPA analyzed the
following measures of human health-related benefits: Reduced lead-
related IQ loss in children aged zero to seven from fish consumption;
reduced cardiovascular disease in adults from lead and arsenic exposure
from fish consumption; reduced mercury-related IQ loss in children
exposed in utero due to maternal fish consumption; and reduced cancer
risk in adults due to arsenic exposure from fish consumption. EPA
monetized these human health benefits by estimating the change in the
expected number of individuals experiencing adverse human health
effects in the populations exposed to steam electric discharges and/or
reduced exposure levels, and valuing these changes using a variety of
monetization approaches.
    These are not the only human health benefits expected to result
from the final rule. EPA also estimated additional human health
benefits derived from changes in air emissions. These additional
benefits are discussed separately in Section XIV.B.4.
a. Monetized Human Health Benefits From Surface Water Quality
Improvements
    EPA estimated health risks from the consumption of contaminated
fish from waterbodies within 50 miles of households. EPA used Census
Block population data, state-specific average fishing rates, and data
on fish consumption advisories to estimate the exposed population. EPA
used cohort-specific fish consumption rates and waterbody-specific fish
tissue concentration estimates to calculate exposure to steam electric
pollutants. Cohorts were defined by age, sex, race/ethnicity, and
fishing mode (recreational/subsistence). EPA used these data to
quantify and monetize the following six categories of human health
benefits, which are further detailed in the BCA Report:
     Benefits from Reduced IQ Loss in Children from Lead
Exposure via Fish Consumption.
     Benefits from Reduced Need for Specialized Education for
Children from Lead Exposure via Fish Consumption.
     Benefits from Reduced Incidence of Cardiovascular Disease
from Lead Exposure via Fish Consumption.
     Benefits of Reduced In Utero Mercury Exposure via Maternal
Fish Consumption.
     Benefits from Reduced Incidence of Cancer from Arsenic
Exposure via Fish Consumption.
     Benefits from Reduced Incidence of Cardiovascular Disease
from Arsenic Exposure via Fish Consumption.
    Table XIV-2 summarizes monetized human health benefits from surface
water quality improvements. EPA estimates that the final rule will
provide human health benefits valued at $16.5 to $17.9 million
annually, using a three percent discount rate, and $11.3 to $11.6
million, using a seven percent discount rate. In addition, EPA
estimated health benefits associated with changes in air emissions, as
discussed in Section XIV.B.4.

      TABLE XIV-2--Human Health Benefits From Surface Water Quality
                              Improvements
------------------------------------------------------------------------
         Benefit category           Annualized benefits  (million 2013$)
------------------------------------------------------------------------
                            3% Discount Rate
------------------------------------------------------------------------
Benefits from Reduced IQ Loss in    $1.0
 Children from Lead Exposure via    ($0.8 to $1.1)
 Fish Consumption \a\.
Benefits from Reduced Need for      <0.1
 Specialized Education for
 Children from Lead Exposure via
 Fish Consumption.
Benefits from Reduced Incidence of  12.8
 Cardiovascular Disease (CVD) from
 Lead Exposure via Fish
 Consumption.
Benefits of Reduced In Utero        3.5
 Mercury Exposure via Maternal      (2.9 to 4.0)
 Fish Consumption \a\.
Benefits from Reduced Incidence of  <0.1
 Cancer from Arsenic Exposure via
 Fish Consumption.
    Subtotal \b\..................  16.5 to 17.9
                                    (15.2 to 16.7)
------------------------------------------------------------------------
                            7% Discount Rate
------------------------------------------------------------------------
Benefits from Reduced IQ Loss in    0.2
 Children from Lead Exposure via    (0.1 to 0.2)
 Fish Consumption \a\.
Benefits from Reduced Need for      <0.1
 Specialized Education for
 Children from Lead Exposure via
 Fish Consumption.
Benefits from Reduced Incidence of  10.7
 CVD from Lead Exposure via Fish
 Consumption.
Benefits of Reduced In Utero        0.6
 Mercury Exposure via Maternal      (0.5 to 0.7)
 Fish Consumption \a\.
Benefits from Reduced Incidence of  <0.1
 Cancer from Arsenic Exposure via
 Fish Consumption.
    Subtotal \b\..................  11.4
                                    (10.7 to 11.0)
------------------------------------------------------------------------
\a\ Low end is based on the assumption that the loss of one IQ point
  results in the loss of 1.76% of lifetime earnings (following Schwartz,
  1994); high end is based on the assumption that the loss of one IQ
  point results in the loss of 2.38% of lifetime earnings (following
  Salkever, 1995).
\b\ Totals may not add up due to independent rounding.

2. Improved Ecological Conditions and Recreational Use Benefits From
Surface Water Quality Improvements
    EPA expects the final rule will provide ecological benefits by
improving ecosystems (aquatic and terrestrial) affected by the electric
power industry's discharges. Benefits associated with changes in
aquatic life include restoration of sensitive species, recovery of
diseased species, changes in taste-and odor-producing algae, changes in
dissolved oxygen (DO), increased assimilative capacity of affected
waters, and improved recreational activities. Activities such as
fishing, swimming, wildlife viewing, camping, waterfowl hunting, and
boating may be enhanced when risks to aquatic life and perceivable
water quality effects associated with pollutants are reduced.
    EPA was able to monetize several categories of ecological benefits
associated with this final rule, including recreational use and nonuse
(existence, bequest, and altruistic) benefits from improvements in the
health of aquatic environments, and nonuse benefits from increased
populations of threatened and endangered species. As shown in Table
XIV-1, the Agency quantified and monetized two main benefit
subcategories, discussed below: (1) Benefits from improvements in
surface water quality, and (2) benefits from improved protection of
threatened and endangered (T&E) species.
a. Improvements in Surface Water Quality
    EPA expects the final rule will improve aquatic habitats and human
welfare by reducing concentrations of harmful pollutants such as
arsenic, cadmium, chromium, lead, mercury, selenium, nitrogen,
phosphorus, and suspended sediment. As a result, some of the waters
that were not usable for recreation under the baseline discharge
conditions may become usable following the rule, thereby benefiting
recreational users. Waters that have been used for recreation under the
baseline conditions can become more attractive by making recreational
trips even more enjoyable. The final rule is also expected to generate
nonuse benefits from bequest, altruism, and existence motivations.
Individuals may value knowing that water quality is being maintained,
ecosystems are being protected, and species populations are healthy,
independent of any use.
    EPA estimates that approximately 19,600 reach miles will improve as
a result of the final rule, as indicated by a higher post-compliance
water quality index (WQI) score. The WQI translates water quality
measurements, gathered for multiple parameters that are indicative of
various aspects of water quality, into a single numerical indicator
that reflects achievement of quality consistent with the suitability
for certain uses.
    EPA estimated monetized benefit values using a revised version of
the meta-regression of surface water valuation studies used in the
benefit-cost analysis of the proposed ELGs (DCN SE03172). Using a meta-
dataset of 51 studies published between 1985 and 2011, EPA developed a
meta-regression model that predicts how marginal willingness to pay
(WTP) for water quality improvements depends on a variety of
methodological, population, resource, and water quality change
characteristics. EPA developed two versions of the meta-regression
model: The first model (Model 1) provides a central estimate of non-
market benefits, while the second model (Model 2) provides a range of
estimates to account for uncertainty in the resulting WTP values.
Chapter 4 of the BCA provides more details on the meta-regression
models and analysis.
    EPA estimated economic values of water quality improvements at the
Census block group level. Water quality improvements are measured as a
length-weighted average of the changes in WQI for waters within 100
miles of the center of each Census block; these waters includes both
waters improving as a result of the final rule and waters not affected
by steam electric plant discharges but which may be substitutes for
improved waters.
    EPA first estimated annual household marginal WTP values for a
given Census block group using the meta- regression

models (Model 1 and Model 2) and multiplied this marginal WTP by the
annual average water quality change for the Census block group to
obtain the annual household WTP.
    EPA then estimated total WTP values by multiplying the annual
household WTP values by the total number of households within a Census
block group. EPA annualized the stream of future benefits, expressed in
2013 dollars, using both 3 and 7 percent discount rates.
    Total national benefits are the sum of estimated Census block
group-level WTP across all block groups for which at least one
waterbody within 100 miles is improved.
    Average annual household WTP estimates for the final ELGs range
from $0.32 on the low end to $1.77 on the high end, with a central
estimate of $0.45. An estimated 84.5 million households reside in
Census block groups within 100 miles of affected reaches. The total
annualized benefits of water quality improvements resulting from
reduced metal, nutrient, and sediment pollution in the approximately
19,600 reach miles improving under the final ELGs range from $23.2
million to $129.5 million with a central estimate of $31.3 million
using a three percent discount rate and $18.5 million to $103.4 million
with a central estimate of $25.1 million using a seven percent discount
rate.
b. Benefits to Threatened and Endangered Species
    To assess the potential for impacts on T&E species (both aquatic
and terrestrial), EPA analyzed the overlap between waters currently
exceeding wildlife-based national recommended WQC, but expected to have
no wildlife national recommended WQC exceedances as a result of the
final rule, and the known critical habitat locations of approximately
631 T&E species. EPA examined the life history traits of potentially
affected T&E species to categorize species by the potential for
population impacts likely to occur as a result of changes in water
quality. Chapter 5 of the BCA Report details the methodology.
    EPA determined that of 15 species whose recovery may be enhanced by
the final rule, three fish species and one salamander species may
experience changes in population growth rates as a result of the final
rule. To quantify the benefits to T&E species, EPA weighted minimal
population growth assumptions (0.5, 1, or 1.5 percent) by the percent
of reaches used by T&E species that are expected to meet wildlife-based
national recommended WQC because of the final rule.
    The T&E species expected to benefit from the rule include one
species of sturgeon and two species of minnows. All of these species
have nonuse values, including existence, bequest, altruistic, and
ecological service values, apart from human uses or motives. EPA
estimated the economic values of increased T&E species populations
using a benefit function transfer approach based on a meta-analysis of
31 stated preference studies eliciting WTP for these changes
(Richardson and Loomis 2009). Because the underlying metadata do not
include amphibian valuation studies, EPA was unable to monetize any
benefits for potential population increases of Hellbender salamander.
EPA estimates annualized benefits to T&E species of approximately $0.02
million, using either a three percent or seven percent discount rate.
3. Market and Productivity Benefits
a. Benefits From Reduced Magnitude of Impoundment Failures
    Operational changes that plants choose to make to meet requirements
in the final rule may cause some plants to reduce their reliance on
impoundments to handle their waste. EPA expects these changes to reduce
the magnitude of impoundment failures and the resulting accidental, and
sometimes catastrophic releases, of CCRs.
    To assess the benefits associated with changes in impoundment use,
EPA estimated the costs associated with expected releases under
baseline conditions (assuming no change in operations relative to
expected operations under the CCR and CPP rules) and for projected
reductions in the amount of CCR waste managed by impoundments. EPA
performed the calculations for each of the 883 to 925 impoundments
identified at steam electric power plants,\54\ and for each year
between 2016 and 2042. EPA then calculated benefits as the difference
between expected release costs for the final rule and expected release
costs under baseline conditions.
---------------------------------------------------------------------------

    \54\ The 883 to 925 impoundments represent the estimated number
of impoundments expected to operate after accounting for the
projected effects of the CCR rule and CPP rule, relative to the
initial universe of 1,070 impoundments located at 347 plants (out of
the total universe of 1,080 steam electric plants). The range of
impoundments reflects different assumptions regarding the projected
effects of the CPP rule on impoundment operations. See Chapter 6 in
the BCA for more information.
---------------------------------------------------------------------------

    To estimate the number of release events that may be avoided as a
result of the ELGs, EPA followed the same approach used by EPA for its
RIA for the CCR rule. The approach relies on estimated failure rates
and capacity factors for two different types of releases (wall breach
and other release) and two categories of impoundments (big and small).
For the final steam electric ELG rule analysis, EPA used baseline
release-rate assumptions that account for changes projected to result
from implementation of the CCR rule. As detailed in Chapter 6 of the
BCA Report, EPA calculated the expected costs of an impoundment
release, including cleanup, natural resource damages (NRD),\55\ and
transaction costs.\56\
---------------------------------------------------------------------------

    \55\ NRD include only the resource restoration and compensation
values; they do not include cleanup costs (or legal costs).
    \56\ For this analysis, transaction costs include the costs
associated with negotiating NRD, determining responsibility among
potentially responsible parties, and litigating details regarding
settlements and remediation. These activities involve services,
whether performed by the complying entity or other parties that EPA
expects would be needed in the absence of this regulation, in the
event of an impoundment release. Note that the transaction costs do
not include fines, cleanup costs, damages, or other costs that
constitute transfers or are already accounted for in the other
categories analyzed separately.
---------------------------------------------------------------------------

    Using the approach above, EPA estimates the annualized benefits of
the final rule are $95.6 million to $102.9 million using a three
percent discount rate, and $77.7 million to $83.7 million using a seven
percent discount rate.
b. Benefits From Increased Marketability of Coal Combustion Residuals
    The final rule may enhance the ability of steam electric power
plants to market coal combustion byproducts for beneficial use by
converting from wet to dry handling of fly ash, bottom ash and FGD
waste. In particular, EPA evaluated the potential benefits from the
increased marketability of fly ash as a substitute for Portland cement
in concrete production and fly and bottom ashes as substitutes for sand
and gravel in fill applications. Based on the change in the quantity of
CCRs handled dry and state-level demand for beneficial use applications
of CCRs, EPA calculated avoided disposal costs and life-cycle benefits
from avoiding the production of virgin materials. Chapter 10 of the BCA
Report details the methodology.
    EPA estimates the annualized benefits of the final rule at $30.8
million using a three percent discount rate, and $31.1 million using a
seven percent discount rate.
4. Air-Related Benefits (Human Health and Avoided Climate Change
Impacts)
    EPA expects the final rule to affect air pollution through three
main mechanisms: (1) Additional auxiliary electricity use by steam
electric power

plants to operate wastewater treatment, ash handling, and other
systems, which EPA predicts that plants will use to meet the new
effluent limitations and standards; (2) additional transportation-
related air emissions due to the increased trucking of CCR waste to
landfills; and (3) the change in the profile of electricity generation
due to the relatively higher cost to generate electricity at plants
incurring compliance costs for the final ELGs. Changes in the profile
of generation can result in lower or higher emissions of air pollutants
because of variability in emission factors for different types of
electric generating units. For this analysis, the changes in air
emissions are based on the change in dispatch of generation units
projected by IPM V5.13, as a result of overlaying the costs of meeting
the final ELGs onto steam electric generating units' production costs.
As discussed in Section IX.C.1, the IPM analysis accounts for the
effects of other regulations affecting the electric power sector.
    EPA estimated the human health and other benefits resulting from
net changes in air emissions of three pollutants: NOX,
SO2, and CO2. NOX and SOX
are known precursors to fine particles (PM2.5), a criteria
air pollutant that has been associated with a variety of adverse health
effects--most notably, premature mortality, non-fatal heart attacks,
hospital admissions, emergency department visits, upper and lower
respiratory symptoms, acute bronchitis, aggravated asthma, lost work
days, and acute respiratory symptoms. CO2 is a key
greenhouse gas that is linked to a wide range of climate change
effects.
    EPA used average benefit-per-ton estimates to value benefits of
changes in NOX and SO2 emissions, and social cost
of carbon (SCC) estimates to value benefits of changes in
CO2 emissions. The calculations are based on the net changes
in air emissions and reflect the net reductions in CO2 and
NOX emissions during the entire period of analysis, and the
net increase in SO2 emissions in 2023-2027, and net decline
in SO2 emissions during the rest of the period. The values
are specific to the years 2016, 2020, 2025, and 2030. Because they are
almost linear as a function of year, EPA interpolated benefits per ton
values for the intermediate years (e.g., between 2020 and 2025) and
projected values for the years from 2031 through 2042 by linear
regression. While extrapolating introduces some uncertainty, as it does
not account for meteorological and air quality changes over time, this
approach is a reasonable one, given available information.
    Chapter 7 of the BCA Report provides the details of this analysis.
As shown in Table XIV-3, EPA estimates that the final rule will provide
human health benefits valued at $144.7 million using a three percent
discount rate, and $108.8 million using a seven percent discount rate.
The rule is expected to provide air-related benefits from changes in
CO2 emissions valued at $139.8 million, using a three
percent discount rate.

  Table XIV-3--Annualized Benefits of Changes in NOX, SO2, and CO2 Air
                                Emissions
                            [Million 2013$]a
------------------------------------------------------------------------
                                                             7 Percent
            Benefit category                 3 Percent     discount rate
                                           discount rate         b
------------------------------------------------------------------------
Human health benefits from reduced                $144.7          $108.8
 morbidity and mortality from exposure
 to NOX, SO2 and particulate matter
 (PM2.5)................................
Avoided climate change impacts from CO2           $139.8          $139.8
 emissions \b\..........................
    Total...............................          $284.5          $248.6
------------------------------------------------------------------------
a Consistent with the assumptions used for the IPM analyses described in
  Section IX.C, EPA estimated the benefits relative to a baseline that
  includes the CPP rule.
b EPA used the SCC based on a three percent discount rate to estimate
  values presented for the seven percent discount rate. EPA uses three
  percent to discount CO2-related benefits and seven percent to discount
  benefits from changes in NOX and SO2 emissions. See Section 7.1 of the
  BCA for details on the methodology.

5. Benefits From Reduced Water Withdrawals (Increased Availability of
Ground Water Resources)
    Steam electric power plants use water for handling waste (e.g., fly
ash, bottom ash) and for operating wet FGD scrubbers. By eliminating or
reducing water used in sluicing operations or prompting the recycling
of water in FGD wastewater treatment systems, the ELGs are expected to
reduce water withdrawals from surface waters and reduce demand on
aquifers, in the case of plants that rely on ground water sources.
    EPA estimated the benefits of reduced ground water withdrawals
based on avoided costs of ground water supply. For each relevant plant,
EPA multiplied the reduction in ground water withdrawal (in gallons per
year) by water costs of about $1,231 per acre-foot. Chapter 8 of the
BCA Report provides the details of this analysis. EPA estimates the
annualized benefits of reduced ground water withdrawals are less than
$0.1 million annually. Due to data limitations, EPA was not able to
monetize the benefits from reduced surface water withdrawals. Chapter 8
of the BCA Report provides additional detail on benefits from reducing
surface water withdrawals.

C. Total Monetized Benefits

    Using the analysis approach described above, EPA estimates annual
total benefits of the final rule for the five monetized categories at
approximately $450.6 million to $565.6 million (at a three percent
discount rate and $387.3 million to $478.4 million at a seven percent
discount rate) (Table XIV-4).

  Table XIV-4--Summary of Total Annualized Monetized Benefits of Final
                                  Rule
------------------------------------------------------------------------
                                                          Annualized
                                                           monetized
                  Benefit category                    benefits  (million
                                                            2013$)
------------------------------------------------------------------------
                         3 Percent Discount Rate
------------------------------------------------------------------------
Human Health Benefits from Surface Water                  $16.5 to $17.9
 Improvements a d...................................

Improved Ecological Conditions and Recreational Uses     $23.3 to $129.5
 a b d..............................................
Market and Productivity Benefits (impoundment           $126.4 to $133.7
 failure and ash marketing).........................
Human Health Benefits from Air Quality Improvements.              $144.7
Other Air-Related Benefits (climate change).........              $139.8
Reduced Water Withdrawals...........................               <$0.1
                                                     -------------------
    Total benefits..................................    $450.6 to $565.6
------------------------------------------------------------------------
                         7 Percent Discount Rate
------------------------------------------------------------------------
Human Health Benefits from Surface Water                  $11.3 to $11.6
 Improvements a.....................................
Improved Ecological Conditions and Recreational Uses     $18.6 to $103.4
 a b................................................
Market and Productivity Benefits (impoundment           $108.8 to $114.8
 failure and ash marketing).........................
Human Health Benefits from Air Quality Improvements.              $108.8
Other Air-Related Benefits c (climate change).......              $139.8
Reduced Water Withdrawals...........................               <$0.1
                                                     -------------------
    Total benefits..................................    $387.3 to $478.4
------------------------------------------------------------------------
\a\ Values represent mean benefit estimates. Totals may not add up due
  to independent rounding.
\b\ There may be some, expected to be small, overlap between the
  willingness-to-pay (WTP) for surface water quality improvements and
  WTP for benefits to threatened and endangered species.
\c\ EPA used the SCC based on a three percent discount rate and
  discounted CO2-related benefits using a three percent discount rate,
  as compared to benefits in other categories, which are discounted
  using the seven percent discount rate.
\d\ Estimates for this benefit category do not reflect revised pollutant
  loadings, which could result in lower monetized benefits. See Section
  1.4.3 of the Benefit Cost Analysis for this rule for details.

D. Other Benefits

    The monetized benefits of this final rule do not account for all
benefits because, as described above, EPA is unable to monetize some
categories. Examples of benefit categories not reflected in these
estimates include other cancer and non-cancer health benefits, reduced
cost of drinking water treatment, avoided ground water contamination
corrective action costs, reduced vulnerability to drought, and reduced
aquatic species mortality from reduced surface water withdrawal. The
BCA Report discusses these benefits qualitatively, indicating their
potential magnitude where possible.

XV. Cost-Effectiveness Analysis

    EPA often uses cost-effectiveness analysis in the development and
revision of ELGs to evaluate the relative efficiency of alternative
regulatory options in removing toxic pollutants from effluent
discharges to the nation's waters. Although not required by the CWA,
and not a determining factor for establishing BAT and PSES, cost-
effectiveness analysis can be a useful tool for describing regulatory
options that address toxic pollutants.

A. Methodology

    The cost-effectiveness of a regulatory option is defined as the
incremental annual cost (in 1981 constant dollars to facilitate
comparison to ELGs for other industrial categories promulgated over
different years) per incremental toxic-weighted pollutant removals for
that option. This definition includes the following concepts:
    Toxic-weighted removals. The estimated reductions in pollution
discharges, or pollutant removals, are adjusted for toxicity by
multiplying the estimated removal quantity for each pollutant by a
normalizing toxic weight (toxic weighting factor). The toxic weight for
each pollutant measures its toxicity relative to copper, with more
toxic pollutants having higher toxic weights. The use of toxic weights
allows the removals of different pollutants to be expressed on a
constant toxicity basis as toxic pound-equivalents (lb-eq). In the case
of indirect dischargers, the removal also accounts for the
effectiveness of treatment at POTWs and reflects the toxic-weighted
pounds remaining after POTW treatment. The cost-effectiveness analysis
does not address the removal of conventional pollutants (e.g., TSS) or
nutrients (nitrogen, phosphorus), nor does it address the removal of
bulk parameters, such as COD.
    Annual costs. The costs used in the cost-effectiveness analysis are
the estimated annualized pre-tax costs described in Section IX,
restated in 1981 dollars as a convention to allow comparisons with the
reported cost effectiveness of other effluent guidelines.
    The result of the cost-effectiveness calculation represents the
unit cost (in constant 1981 dollars) of removing the next pound-
equivalent of pollutants. EPA calculates cost-effectiveness separately
for direct and indirect dischargers. EPA notes that only three steam
electric power plants are estimated to incur costs associated with the
final PSES requirements, as compared to 130 plants estimated to incur
costs associated with the final BAT requirements.
    Appendix F of the RIA details the analysis.

B. Results

    Collectively, the final BAT requirements have a cost-effectiveness
ratio of $134/lb-eq ($1981). This cost-effectiveness ratio is well
within the range of cost-effectiveness ratios for BAT requirements in
other industries. A review of approximately 25 of the most recently
promulgated or revised BAT limitations shows BAT cost-effectiveness
ranging from less than $1/lb-eq (Inorganic Chemicals) to $404/lb-eq
(Electrical and Electronic Components), in 1981 dollars.
    Collectively, the final PSES requirements have a cost effectiveness
of $1,228/lb-eq ($1981). This ratio is higher than the cost-
effectiveness for PSES of other industries, which range from less than
$1/lb-eq (Inorganic Chemicals) to $380/lb-eq (Transportation Equipment
Cleaning), in

1981 dollars, based on a review of approximately 25 of the most
recently promulgated or revised categorical pretreatment standards. As
noted above, however, very few plants (three) are indirect dischargers
and the cost-effectiveness for one of the three indirect dischargers
significantly elevates the value for all three combined. EPA calculated
costs for this plant based on a full conversion of its bottom ash
handling system to dry handling. However, it is more likely that this
plant would choose to implement modifications that would enable it to
completely recycle its bottom ash transport water in order to meet the
zero discharge standard, rather than undertake a full conversion. In
that event, the costs to this indirect discharger--and consequently the
cost-effectiveness value for all indirect dischargers, combined--would
be lower.
    Collectively, cost-effectiveness for the entire rule (BAT and PSES)
is $136/lb-eq ($1981).
    For the purposes of calculating pollutant loadings under this
action, EPA's analysis first handled non-detect values in the reported
data by replacing them with a value of one-half of the detection level
for the observation that yielded the non-detect. This methodology is
standard procedure for the ELG program as well as Clean Water Act
assessment and permitting, Safe Drinking Water Act monitoring, and
Resource Conservation and Recovery Act and Superfund programs; and this
approach is consistent with previous ELGs.
    In their comments on the proposed rule, commenters raised the
concern that for some pollutants the loadings calculations
(particularly for bottom ash) were biased high as a result of high non-
detected values in the reported data. These high non-detected values
were the result of not using sufficiently sensitive methods. The view
was expressed that, should the non-detects fall significantly outside
of the range of detected values, assigning them one half of the
detection level would not be sufficient to accurately represent
pollutant loadings and the associated cost-effectiveness of the rule.
    To assess this concern and provide further transparency for this
rulemaking, EPA also implemented a second method of treating non-
detects where all attributed non-detects (i.e., one-half of the
detection limit) that exceeded the highest detected value for a
particular pollutant were deleted. Since it is possible that a plant's
actual loading fell outside the range of detected values of all of the
plants, this methodology served to place an upper bound on the effect
of non-detects on the pollutant loading and cost-effectiveness
calculations. EPA's decision to incorporate this second approach for
bottom ash transport water in this rulemaking reflects the exceptional
circumstance in this case where there are so few detected observations
in combination with wide variability in sample-specific detection
values for the non-detected observations for 6 analytes. For a full
discussion of the analysis method and results, see Section 10.2.2 of
the TDD and Section F-4 of the RIA. EPA found that this second method
of treatment of non-detects affects the averaged pollutant
concentrations for 6 out of the 44 analytes, alters pollutant loadings
and decreases identified TWPE loadings and removals in comparison to
method 1. EPA also calculated the cost-effectiveness for the bottom ash
wastestream using the averaged pollutant concentrations derived from
method 2, and found in comparison to method 1 the method 2 analysis
changed the cost-effectiveness value from $314/TWPE to $457/TWPE for
this wastestream and cost-effectiveness of the full rule from $136/TWPE
to $149/TWPE. Where appropriate in the TDD, RIA, BCA and certain other
documents for the rule, EPA has reflected the results for pollutant
loadings and cost effectiveness under both of these approaches. EPA's
determination of BAT and the standards and rationale supporting that
determination, are discussed in Section VIII; the differences in
loadings and cost effectiveness associated with incorporating this
second approach to addressing uncertainty related to non-detects do not
alter that determination.

XVI. Regulatory Implementation

A. Implementation of the Limitations and Standards

    The requirements in this rule apply to discharges from steam
electric power plants through incorporation into NPDES permits issued
by the EPA or authorized states under Section 402 of the Act and
through local pretreatment programs under Section 307 of the Act.
Permits or control mechanisms issued after this rule's effective date
must incorporate the ELGs, as applicable. Also, under CWA section 510,
states can require effluent limitations under state law as long as they
are no less stringent than the requirements of this rule. Finally, in
addition to requiring application of the technology-based ELGs in this
rule, CWA section 301(b)(1)(C) requires the permitting authority to
impose more stringent effluent limitations, as necessary, to meet
applicable water quality standards.
1. Timing
    The direct discharge limitations in this rule apply only when
implemented in an NPDES permit issued to a discharger after the
effective date of this rule. Under the CWA, the permitting authority
must incorporate these ELGs into NPDES permits as a floor or a minimum
level of control. While the rule is effective on its effective date
(see DATES section at the beginning of this preamble), the rule allows
a permitting authority to determine a date when the new effluent
limitations for FGD wastewater, fly ash transport water, bottom ash
transport water, FGMC wastewater, and gasification wastewater apply to
a given discharger. The permitting authority must make these final
effluent limitations applicable on or after November 1, 2018. For any
final effluent limitation that is specified to become applicable after
November 1, 2018, the specified date must be as soon as possible, but
in no case later than December 31, 2023. For dischargers in the
voluntary incentives program choosing to meet effluent limitations for
FGD wastewater based on use of evaporation technology, the date for
meeting those limitations is December 31, 2023.
    For combustion residual leachate, and for certain wastestreams (FGD
wastewater, fly ash transport water, bottom ash transport water, FGMC
wastewater, and gasification wastewater) at oil-fired generating units
and small generating units (50 MW or less), the final BAT limitations
apply on the date that a permit is issued to a discharger, following
the effective date of this rule. The rule does not build in an
implementation period for meeting these limitations, as the BAT
limitation on TSS is equal to the previously promulgated BPT limitation
on TSS.
    Pretreatment standards are self-implementing, meaning they apply
directly, without the need for a permit. In this rule, the pretreatment
standards for existing sources must be met by November 1, 2018.
    The requirements for new source direct and indirect discharges
(NSPS and PSNS) provide no extended implementation period. NSPS apply
when any NPDES permit is issued to a new source direct discharger,
following the effective date of this rule; PSNS apply to any new source
discharging to a POTW, as of the effective date of the final rule.
    Regardless of when a plant's NPDES permit is ready for renewal, the
plant

should immediately begin evaluating how it intends to comply with the
requirements of the final ELGs. In cases where significant changes in
operation are appropriate, the plant should discuss such changes with
the permitting authority and evaluate appropriate steps and a timeline
for the changes, even prior to the permit renewal process.
    In cases where a plant's final NPDES permit will be issued after
the effective date of the final ELGs, but before November 1, 2018, the
permitting authority should apply limitations based on the previously
promulgated BPT limitations or the plant's other applicable permit
limitations until at least November 1, 2018. The permitting authority
should also determine what date represents the soonest date, beginning
November 1, 2018, that the plant can meet the final BAT limitations in
this rule. The permit should require compliance with the final BAT
limitations by that date, making clear that in no case shall the
limitations apply later than December 31, 2023. Then, for permits that
might be administratively continued, the final date will apply, even if
that date is at the end of the implementation period. For permits that
are issued on or after November 1, 2018, the permitting authority
should determine the earliest possible date that the plant can meet the
limitations in this rule (but in no case later than December 31, 2023),
and apply the final limitations as of that date (BPT limitations or the
plant's other applicable permit limitations would apply until such
date).
    As specified by the rule, the ``as soon as possible'' date
determined by the permitting authority is November 1, 2018, unless the
permitting authority determines another date after receiving
information submitted by the discharger.\57\ Assuming that the
permitting authority receives relevant information from the discharger,
in order to determine what date is ``as soon as possible'' within the
implementation period, the permitting authority must then consider the
following factors:
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    \57\ Even after the permitting authority receives information
from the discharger, it still may be appropriate to determine that
November 1, 2018, is ``as soon as possible'' for that discharger.
---------------------------------------------------------------------------

    (a) Time to expeditiously plan (including to raise capital),
design, procure, and install equipment to comply with the requirements
of the final rule;
    (b) Changes being made or planned at the plant in response to
greenhouse gas regulations for new or existing fossil fuel-fired power
plants under the Clean Air Act, as well as regulations for the disposal
of coal combustion residuals under subtitle D of the Resource
Conservation and Recovery Act;
    (c) For FGD wastewater requirements only, an initial commissioning
period to optimize the installed equipment; and
    (d) Other factors as appropriate.
    With respect to the first factor, the permitting authority should
evaluate what operational changes are expected at the plant to meet the
new BAT limitations for each wastestream, including the types of new
treatment technologies that the plant plans to install, process changes
anticipated, and the timeframe estimated to plan, design, procure, and
install any relevant technologies. As specified in the second factor,
the permitting authority must also consider scheduling for installation
of equipment, which includes a consideration of plant changes planned
or being made to comply with certain other key rules that affect the
steam electric power generating industry. As specified in the third
factor, for the FGD wastewater requirements only, the permitting
authority must consider whether it is appropriate to allow more time
for implementation, in addition to the three years before
implementation of the rule begins on November 1, 2018, in order to
ensure that the plant has appropriate time to optimize any relevant
technologies. EPA's record demonstrates that plants installing the FGD
technology basis spent several months optimizing its operation (initial
commissioning period). Without allowing additional time for
optimization, the plant would likely not be able to meet the
limitations because they are based on the operation of optimized
systems. See TDD Section 14 for additional discussion and examples
regarding implementation of the final ELGs into NPDES permits.
    The ``as soon as possible'' date determined by the permitting
authority may or may not be different for each wastestream. EPA
recommends that the permitting authority provide a well-documented
justification of how it determined the ``as soon as possible'' date in
the fact sheet or administrative record for the permit. If the
permitting authority determines a date later than November 1, 2018, the
justification should explain why allowing additional time to meet the
limitations is appropriate, and why the discharger cannot meet the
final effluent limitations as of November 1, 2018. In cases where the
plant is already operating the BAT technology basis for a specific
wastestream (e.g., dry fly ash handling system), operates the majority
of the BAT technology basis (e.g., FGD chemical precipitation and
biological treatment, without sulfide addition), or expects that
relevant treatment and process changes will be in place prior to
November 1, 2018, it would not generally be appropriate to allow
additional time beyond that date. Regardless, in all cases, the
permitting authority must make clear in the permit what date the plant
must meet the limitations, and that date may be no later than December
31, 2023.
    Where a discharger chooses to participate in the voluntary
incentives program and be subject to effluent limitations for FGD
wastewater based on evaporation, the permitting authority must allow
the plant up to December 31, 2023, to meet those limitations; again,
the permit must make clear that the plant must meet the final
limitations by December 31, 2023.
2. Applicability of NSPS/PSNS
    In 1982, EPA promulgated NSPS/PSNS for certain discharges from new
sources. Those sources that were subject to the 1982 NSPS/PSNS will
continue to be subject to such standards under this final rule. In
addition, sources to which the 1982 NSPS/PSNS apply are also subject to
the final BAT/PSES requirements in this rule because they will be
existing sources with respect to such new requirements. See 40 CFR
423.15(a) and 40 CFR 423.17(a).
3. Legacy Wastewater
    For purposes of the BAT limitations in this rule, legacy wastewater
is FGD wastewater, fly ash transport water, bottom ash transport water,
FGMC wastewater, and gasification wastewater generated prior to the
date established by the permitting authority that is as soon as
possible beginning November 1, 2018, but no later than December 31,
2023 (see Section VIII.C.7 and Section VIII.C.8).\58\ Direct discharges
of legacy wastewater are, under this rule, subject to BAT effluent
limitations on TSS in such wastewater, which are equal to the existing
BPT effluent limitations on TSS in fly ash transport water, bottom ash
transport water, and low volume waste sources.\59\ See TDD Section 14
for additional information regarding the legacy wastewater BAT
limitations and

guidance on implementing them into NPDES permits.
---------------------------------------------------------------------------

    \58\ For plants in the voluntary incentives program, legacy FGD
wastewater is FGD wastewater generated prior to December 31, 2023
(see Section VIII.C.13).
    \59\ The final rule does not establish PSES standards for legacy
wastewater for these wastestreams because TSS and the pollutants
they represent are effectively treated by POTWs; and, therefore, EPA
has determined that they do not pass through the POTW (see Section
VIII.E).
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4. Combined Wastestreams
    Most steam electric power plants combine various wastewaters (e.g.,
FGD wastewater, fly ash and bottom ash transport water) and cooling
water either before or after treatment. In such cases, to derive
effluent limitations or standards at the point of discharge, the
permitting authority typically combines the allowable pollutant
concentrations loadings for each set of requirements to arrive at a
specific limitation or standard, per pollutant, for the combined
wastestream, using the building block approach or combined waste stream
formula (CWF). See NPDES Permit Writer's Manual and 40 CFR 403.6. For
concentration-based limitations, rather than mass-based limitations,
the effluent limitation or standard for the mixed wastestream is a
flow-weighted combination of the appropriate concentration-based
limitations or standards for each applicable wastestream. Such a
calculation is relatively straightforward if the individual
wastestreams are subject to limitations or standards for the same
pollutants and the flows of the wastestreams are relatively consistent.
This, however, is not the case for all wastestreams at steam electric
power plants.
    Because EPA anticipates that permitting authorities will apply
concentration-based limitations or standards, rather than mass-based
limitations or standards, in NPDES permits for steam electric power
plants, proper application of the building block approach or CWF is
necessary to ensure that the reduced pollutant concentrations observed
in a combined discharge reflect proper treatment and control strategies
rather than dilution. Where a regulated wastestream is combined with a
well-known dilution flow, such as cooling water, uncontaminated
stormwater, or cooling tower blowdown, the concentration-based
limitation for the regulated wastestream is reduced by multiplying it
by a factor.\60\ This factor is the total flow for the combined
wastestream minus the dilution flow divided by the total flow for the
combined wastestream. In some cases, a wastestream (e.g., FGD
wastewater) containing a regulated pollutant (e.g., selenium or
mercury) combines with other wastestreams that contain the same
pollutant, but that are not regulated for that pollutant (e.g., legacy
wastewater contained in a surface impoundment). In these cases, based
on the information in its record, EPA strongly recommends that in
applying the building block approach or CWF to the regulated pollutant
(selenium or mercury, in the example above), permitting authorities
either treat the wastestream that does not have a limitation or
standard for the pollutant (legacy wastewater contained in a surface
impoundment, in the example above) as a dilution flow or determine a
concentration for that pollutant based on representative samples of
that wastestream.\61\
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    \60\ As is the case with a single regulated wastestream, if the
combined wastestream is not discharged, then the limitations and
standards are not applicable.
    \61\ EPA does not recommend that the permitting authority assume
that the pollutant is present at a significant level in the
wastestream that does not have a relevant limitation or standard and
just apply the same limitation or standard for the pollutant to the
mixed wastestream. This will not ensure that treatment and control
strategies are being employed to achieve the limitations or
standards, rather than simply dilution.
---------------------------------------------------------------------------

    In all cases where the permitting authority is applying the
building block approach or CWF, except where a regulated wastestream is
mixed with a dilution wastestream, the permitting authority must also
determine the flow rate for use in the building block approach or CWF.
EPA strongly recommends that the permitting authority calculate the
flow rate based on representative flow rates for each wastestream.
    EPA recommends that, where a steam electric power plant chooses to
combine two or more wastestreams that would call for the use of the
building block approach or CWF to determine the appropriate limitations
or standards for the combined wastestream, the plant should be
responsible for providing sufficient data that reflect representative
samples of each of the individual wastestreams that make up the
combined wastestream. EPA strongly recommends that the representative
samples reflect a study of each of the applicable wastestreams that
covers the full range of variability in concentration and flow for each
wastestream.
    EPA anticipates that proper application of the building block
approach or CWF will result in combined wastestream limitations and
standards that will enable steam electric power plants to combine
certain wastestreams, while also ensuring that the plant is actually
treating its wastewater as intended by the Act and this rule, rather
than simply diluting it. EPA's record demonstrates, however, that
combined wastestream limitations and standards at the point of
discharge, derived using the building block approach or CWF, may be
impractical or infeasible for some combined wastestreams because the
resulting limitation or standard for any of the regulated pollutants in
the combined wastestream would fall below analytical detection levels.
In such cases, the permitting authority should establish internal
limitations on the regulated wastestream, prior to mixing of the
wastestream with others, as authorized pursuant to 40 CFR 122.45(h) and
40 CFR 403.6.\62\ See TDD Section 14 for more examples and details
about this guidance.
---------------------------------------------------------------------------

    \62\ As described earlier for wastestreams with zero discharge
limitations or standards, just because a wastestream with a numeric
limitation or standard is moved, prior to discharge, for use in
another plant process, that does not mean that the wastestream
ceases to be subject to the applicable numeric limitation or
standard, assuming that the wastestream is eventually discharged.
---------------------------------------------------------------------------

5. Non-Chemical Metal Cleaning Wastes
    By reserving BAT and NSPS for non-chemical metal cleaning wastes in
this final rule, the permitting authority must continue to establish
such requirements based on BPJ for any steam electric power plant
discharging this wastestream. As explained in Section VIII.I, in
permitting this wastestream, some permitting authorities have
classified it as non-chemical metal cleaning wastes (a subset of metal
cleaning wastes), while others have classified it as a low volume waste
source; NPDES permit limitations for this wastestream thus reflect that
classification. In making future BPJ BAT determinations, EPA recommends
that the permitting authority examine the historical permitting record
for the particular plant to determine how discharges of non-chemical
metal cleaning wastes have been permitted in the past. Using historical
information and its best professional judgment, the permitting
authority could determine that the BPJ BAT limitations should be set
equal to existing BPT limitations or it could determine that more
stringent BPJ BAT limitations should apply. In making a BPJ
determination for new sources, EPA recommends that the permitting
authority consider whether it would be appropriate to base standards on
BPT limitations for metal cleaning wastes or on a technology that
achieves greater pollutant reductions.

B. Upset and Bypass Provisions

    A ``bypass'' is an intentional diversion of wastestreams from any
portion of a treatment facility. An ``upset'' is an exceptional
incident in which there is unintentional and temporary

noncompliance with technology-based permit effluent limitations because
of factors beyond the reasonable control of the permittee. EPA's
regulations concerning bypasses and upsets for direct dischargers are
set forth at 40 CFR 122.41(m) and (n) and for indirect dischargers at
40 CFR 403.16 and 403.17.

C. Variances and Modifications

    The CWA requires application of effluent limitations or
pretreatment standards established pursuant to CWA section 301 to all
direct and indirect dischargers. The statute, however, provides for the
modification of these national requirements in a limited number of
circumstances. The Agency has established administrative mechanisms to
provide an opportunity for relief from the application of the national
effluent limitations guidelines for categories of existing sources for
toxic, conventional, and nonconventional pollutants.
1. Fundamentally Different Factors Variance
    EPA can develop, with the concurrence of the state, effluent
limitations or standards different from the otherwise applicable
requirements for an individual existing discharger if that discharger
is fundamentally different with respect to factors considered in
establishing the effluent limitations guidelines or standards. Such a
modification is known as a Fundamentally Different Factors (FDF)
variance.
    EPA, in its initial implementation of the effluent guidelines
program, provided for the FDF modifications in regulations, which were
variances from the BPT effluent limitations, BAT limitations for toxic
and nonconventional pollutants, and BCT limitations for conventional
pollutants for direct dischargers. FDF variances for toxic pollutants
were challenged judicially and ultimately sustained by the Supreme
Court in Chem. Mfrs. Ass'n v. Natural Res. Def. Council, 470 U.S. 116,
124 (1985).
    Subsequently, in the Water Quality Act of 1987, Congress added a
new section to the CWA, section 301(n). This provision explicitly
authorizes modifications of the otherwise applicable BAT effluent
limitations, if a discharger is fundamentally different with respect to
the factors specified in CWA section 304 or 403 (other than costs) from
those considered by EPA in establishing the effluent limitations and
standards. CWA section 301(n) also defined the conditions under which
EPA can establish alternative requirements. Under Section 301(n), an
application for approval of a FDF variance must be based solely on (1)
information submitted during rulemaking raising the factors that are
fundamentally different or (2) information the applicant did not have
an opportunity to submit. The alternate limitation must be no less
stringent than justified by the difference and must not result in
markedly more adverse non-water quality environmental impacts than the
national limitation.
    EPA regulations at 40 CFR part 125, subpart D, authorizing the
Regional Administrators to establish alternative limitations, further
detail the substantive criteria used to evaluate FDF variance requests
for direct dischargers. Thus, 40 CFR 125.31(d) identifies six factors
(e.g., volume of process wastewater, age and size of a discharger's
facility) that can be considered in determining if a discharger is
fundamentally different. The Agency must determine whether, based on
one or more of these factors, the discharger in question is
fundamentally different from the dischargers and factors considered by
EPA in developing the nationally applicable effluent guidelines. The
regulation also lists four other factors (e.g., inability to install
equipment within the time allowed or a discharger's ability to pay)
that cannot provide a basis for an FDF variance. In addition, under 40
CFR 125.31(b) (3), a request for limitations less stringent than the
national limitation can be approved only if compliance with the
national limitations will result in either (a) a removal cost wholly
out of proportion to the removal cost considered during development of
the national limitations, or (b) a non-water quality environmental
impact (including energy requirements) fundamentally more adverse than
the impact considered during development of the national limits. The
legislative history of CWA section 301(n) underscores the necessity for
the FDF variance applicant to establish eligibility for the variance.
EPA's regulations at 40 CFR 125.32(b)(1) and 40 CFR 403.13 impose this
burden upon the applicant. The applicant must show that the factors
relating to the discharge controlled by the applicant's permit that are
claimed to be fundamentally different are, in fact, fundamentally
different from those factors considered by EPA in establishing the
applicable guidelines and standards. In practice, very few FDF
variances have been granted for past ELGs. An FDF variance is not
available to a new source subject to NSPS or PSNS. DuPont v. Train, 430
U.S. 112 (1977).
2. Economic Variances
    Section 301(c) of the CWA authorizes a variance from the otherwise
applicable BAT effluent guidelines for nonconventional pollutants due
to economic factors. See also CWA section 301(l). The request for a
variance from effluent limitations developed from BAT guidelines must
normally be filed by the discharger during the public notice period for
the draft permit. Other filing periods can apply, as specified in 40
CFR 122.21(m)(2). Specific guidance for this type of variance is
provided in ``Draft Guidance for Application and Review of Section
301(c) Variance Requests,'' dated August 21, 1984, available on EPA's
Web site at http://www.epa.gov/npdes/pubs/OWM0469.pdf.
3. Water Quality Variances
    Section 301(g) of the CWA authorizes a variance from BAT effluent
guidelines for certain nonconventional pollutants (ammonia, chlorine,
color, iron, and total phenols) due to localized environmental factors.
As this final rule does not establish limitations or standards for any
of these pollutants, this variance is not applicable to this particular
rule.
4. Removal Credits
    Section 307(b)(1) of the CWA establishes a discretionary program
for POTWs to grant ``removal credits'' to their indirect dischargers.
Removal credits are a regulatory mechanism by which industrial users
can discharge a pollutant in quantities that exceed what would
otherwise be allowed under an applicable categorical pretreatment
standard because it has been determined that the POTW to which the
industrial user discharges consistently treats the pollutant. EPA has
promulgated removal credit regulations as part of its pretreatment
regulations. See 40 CFR 403.7. These regulations provide that a POTW
can give removal credits if prescribed requirements are met. The POTW
must apply to and receive authorization from the Approval Authority. To
obtain authorization, the POTW must demonstrate consistent removal of
the pollutant for which approval authority is sought. Furthermore, the
POTW must have an approved pretreatment program. Finally, the POTW must
demonstrate that granting removal credits will not cause the POTW to
violate applicable federal, state, or local sewage sludge requirements.
40 CFR 403.7(a)(3).

    The U.S. Court of Appeals for the Third Circuit interpreted the CWA
as requiring EPA to promulgate the comprehensive sewage sludge
regulations pursuant to CWA section 405(d)(2)(A)(ii) before any removal
credits could be authorized. See Natural Res. Def. Council v. EPA, 790
F.2d 289, 292 (3d Cir. 1986), cert. denied, 479 U.S. 1084 (1987).
Congress made this explicit in the Water Quality Act of 1987, which
provided that EPA could not authorize any removal credits until it
issued the sewage sludge use and disposal regulations. On February 19,
1993, EPA promulgated Standards for the Use or Disposal of Sewage
Sludge, which are codified at 40 CFR part 503 (58 FR 9248). EPA
interprets the Court's decision in Natural Res. Def. Council v. EPA as
only allowing removal credits for a pollutant if EPA has either
regulated the pollutant in part 503 or established a concentration of
the pollutant in sewage sludge below which public health and the
environment are protected when sewage sludge is used or disposed.
    The part 503 sewage sludge regulations allow four options for
sewage sludge disposal: (1) Land application for beneficial use, (2)
placement on a surface disposal unit, (3) firing in a sewage sludge
incinerator, and (4) disposal in a landfill which complies with the
municipal solid waste landfill criteria in 40 CFR part 258. Because
pollutants in sewage sludge are regulated differently depending upon
the use or disposal method selected, under EPA's pretreatment
regulations the availability of a removal credit for a particular
pollutant is linked to the POTW's method of using or disposing of its
sewage sludge. The regulations provide that removal credits can be
potentially available for the following situations:
    (1) If a POTW applies its sewage sludge to the land for beneficial
uses, disposes of it in a surface disposal unit, or incinerates it in a
sewage sludge incinerator, removal credits can be available for the
pollutants for which EPA has established limits in 40 CFR part 503. EPA
has set ceiling limitations for nine metals in sludge that is land
applied, three metals in sludge that is placed on a surface disposal
unit, and seven metals and 57 organic pollutants in sludge that is
incinerated in a sewage sludge incinerator. 40 CFR 403.7(a)(3)(iv)(A).
    (2) Additional removal credits can be available for sewage sludge
that is land applied, placed in a surface disposal unit, or incinerated
in a sewage sludge incinerator, so long as the concentration of these
pollutants in sludge do not exceed concentration levels established in
40 CFR part 403, appendix G, Table II. For sewage sludge that is land
applied, removal credits can be available for an additional two metals
and 14 organic pollutants. For sewage sludge that is placed on a
surface disposal unit, removal credits can be available for an
additional seven metals and 13 organic pollutants. For sewage sludge
that is incinerated in a sewage sludge incinerator, removal credits can
be available for three other metals 40 CFR 403.7(a)(3)(iv)(B).
    (3) When a POTW disposes of its sewage sludge in a municipal solid
waste landfill that meets the criteria of 40 CFR part 258, removal
credits can be available for any pollutant in the POTW's sewage sludge.
40 CFR 403.7(a)(3)(iv)(C).

D. Site-Specific Water Quality-Based Effluent Limitations

    Depending on site-specific conditions and applicable state water
quality standards, it may be appropriate for permitting authorities to
establish water quality-based effluent limitations on bromide,\63\
especially where steam electric power plants are located upstream from
drinking water intakes.
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    \63\ Some may establish limitations on TDS as an indicator of
bromide because bromide is a component of TDS.
---------------------------------------------------------------------------

    Bromides (a component of TDS) are not directly controlled by the
numeric effluent limitations and standards for existing sources under
this final rule \64\ (although they would be controlled by the NSPS/
PSNS for new sources and by the BAT effluent limitations for existing
sources who choose to participate in the voluntary program and are
subject to the final FGD wastewater limitations based on use of
evaporation technology).
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    \64\ TDS, like all pollutants, are controlled where there are
zero discharge effluent limitations and standards.
---------------------------------------------------------------------------

    Bromide discharges from coal-fired steam electric power plants can
occur because bromide is naturally found in coal and is released as
particulates when the coal is burned, or by the addition of bromide
compounds to the coal prior to burning, or to the flue gas scrubbing
process, to reduce the amount of mercury air pollution that is also
created when coal is burned.
    While bromide itself is not thought to be toxic at levels present
in the environment, its reaction with other constituents in water may
be a cause for concern now and into the future. The bromide ion in
water can form brominated DBPs when drinking water plants treat the
incoming source water using certain disinfection processes including
chlorination and ozonation. Bromide can react with the ozone, chlorine,
or chlorine-based disinfectants to form bromate and brominated and
mixed chloro-bromo DBPs, such as trihalomethanes (THMs) or haloacetic
acids (HAAs) (see DCN SE01920). Studies indicate that exposure to THMs
and other DBPs from chlorinated water is associated with human bladder
cancer (see DCN SE01981 and DCN SE01983). EPA has established the
following MCLs for DBPs:
     0.010 mg/L for bromate due to increased cancer risk from
long-term exposure;
     0.060 for HAAs due to increased cancer risk from long-term
exposure; and
     0.080 mg/L for TTHMs due to increased cancer risk and
liver, kidney or central nervous system problems from long-term
exposure (see DCN SE01909).
    The record indicates that steam electric power plant FGD wastewater
discharges occur near more than 100 public drinking water intakes on
rivers and other waterbodies, and there is evidence that these
discharges are already having adverse effects on the quality of
drinking water sources. A 2014 study by McTigue et. al. identified four
drinking water treatment plants that experienced increased levels of
bromide in their source water, and corresponding increases in the
formation of brominated DBPs, after the installation of wet FGD
scrubbers at upstream steam electric power plants (see DCN SE04503).
    Drinking water utilities are concerned as well, noting that the
bromide concentrations have made it increasingly difficult for them to
meet SDWA requirements for total trihalomethanes (TTHMs) (see DCN
SE01949). And, bromide loadings into surface waters from coal-fired
steam electric power plants could potentially increase in the future as
more plant operators use bromide addition to improve the control of
mercury emissions. The American Water Works Association requested that
EPA ``instruct NPDES permit writers to adequately consider downstream
drinking water supplies in establishing permit requirements for power
plant discharges'' and take other steps to limit adverse consequences
for downstream drinking water treatment plants. EPA agrees that
permitting authorities should carefully consider whether water quality-
based effluent limitations on bromide or TDS would be appropriate for
FGD wastewater discharges from steam electric power plants upstream of
drinking water intakes.

    EPA regulations at 40 CFR 122.44(d)(1) require that each NPDES
permit shall include any requirements, in addition to or more stringent
than effluent limitations guidelines or standards promulgated pursuant
to sections 301, 304, 306, 307, 318 and 405 of the CWA, necessary to
achieve water quality standards established under section 303 of the
CWA, including state narrative criteria for water quality. Furthermore,
those same regulations require that limitations must control all
pollutants, or pollutant parameters (either conventional,
nonconventional, or toxic pollutants) which the Director determines are
or may be discharged at a level which will cause, have the reasonable
potential to cause, or contribute to an excursion above any state water
quality standard, including state narrative criteria for water quality.
    Where the DBP problem described above may be present, water
quality-based effluent limitations for steam electric power plant
discharges may be required under the regulations at 40 CFR
122.44(d)(1), where necessary to meet either numeric criteria (e.g.,
for bromide, TDS or conductivity) or narrative criteria in state water
quality standards. All states have narrative water quality criteria
that are designed to prevent contamination and other adverse impacts to
the states' surface waters. These are often referred to as ``free
from'' standards. For example, a state narrative water quality
criterion for protecting drinking water sources may require discharges
to protect people from adverse exposure to chemicals via drinking
water. These narrative criteria may be used to develop water quality-
based effluent limitations on a site-specific basis for the discharge
of pollutants that impact drinking water sources, such as bromide.
    To translate state narrative water quality criteria and inform the
development of a water quality-based limitation for bromide, it may be
appropriate for permitting authorities to use EPA's established MCLs
for DBPs in drinking water because the presence of bromides in drinking
water can result in exceedances of drinking water MCLs as a result of
interactions during drinking water treatment and disinfection
processes. The limitation would be developed for the purpose of
attaining and maintaining the state's applicable narrative water
quality criterion or criteria and protecting the state's designated
use(s), including the protection of human health. See 40 CFR
122.44(d)(1)(vi).
    For the reasons described above, during development of the NPDES
permit for the steam electric power plant, the permitting authority
should provide notification to any downstream drinking water treatment
plants of the discharge of bromide. EPA recommends that the permitting
authority collaborate with drinking water utilities and their
regulators to determine what concentration of bromides at the PWS
intake is needed to ensure that levels of bromate and DPBs do not
exceed applicable MCLs. The maximum level of bromide in source waters
at the intake that does not result in an exceedance of the MCL for DBPs
is the numeric interpretation of the narrative criterion for protection
of human health and may vary depending on the treatment processes
employed at the drinking water treatment facility. The permitting
authority would then determine the level of bromide that may be
discharged from the steam electric power plant, taking into account
other sources of bromide that may occur, such that the level of bromide
downstream at the intake to the drinking water utility is below a level
that would result in an exceedances of the applicable MCLs for DBPs. In
addition, applicants for NPDES permits must, as part of their permit
application, indicate whether they know or have reason to believe that
conventional and/or nonconventional pollutants listed in Table IV of
Appendix D to 40 CFR part 122, (which includes bromide), are discharged
from each outfall. For every pollutant in Table IV of Appendix D
discharged which is not limited in an applicable effluent limitations
guideline, the applicant must either report quantitative data or
briefly describe the reasons the pollutant is expected to be discharged
as set forth in 40 CFR 122.2l(g)(7)(vi)(A), made applicable to the
States at 40 CFR 123.25(a)(4).
    In addition to requiring the permit applicant to provide a complete
application, including proper wastewater characterization, when issuing
the permit, the permitting authority can incorporate appropriate
monitoring and reporting requirements, as authorized under section
402(a)(2), 33 U.S.C. 1342(a)(2), and implementing regulations at 40 CFR
122.48, 122.44(i), 122.43 and 122.41(1)(4). These requirements apply to
all dischargers and include plants that have identified the presence of
bromide in effluent in significant quantities and that are in proximity
to downstream water treatment plants.

XVII. Related Acts of Congress, Executive Orders, and Agency
Initiatives

A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review

    This action is an economically significant regulatory action that
was submitted to the Office of Management and Budget (OMB) for review.
Any changes made in response to OMB recommendations have been
documented in the docket. EPA prepared an analysis of the potential
costs and benefits associated with this action. This analysis is
contained in Chapter 13 of the BCA Report, available in the docket.
    Table XVII-1 (drawn from Table 13-1 of the BCA Report) provides the
results of the benefit-cost analysis with both costs and benefits
annualized over 24 years and discounted using a three percent discount
rate.

Table XVII-1--Total Monetized Annualized Benefits and Costs of the Final
                              BAT and PSES
           [Millions, 2013$, three percent discount rate] \a\
------------------------------------------------------------------------
                                  Total social costs    Total monetized
                                          \b\              benefits
------------------------------------------------------------------------
Annualized Value................             $479.5    $450.6 to $565.6
------------------------------------------------------------------------
\a\ All costs and benefits were annualized over 24 years and using a
  three percent discount rate.
\b\ Total social costs include compliance costs to facilities.

B. Paperwork Reduction Act

    OMB has previously approved the information collection requirements
contained in the existing regulations 40 CFR part 423 under the
provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and
has assigned OMB control number 2040-0281. The OMB control numbers for
EPA's regulations in 40 CFR are listed in 40 CFR part 9.

    EPA estimated small changes in monitoring costs at steam electric
power plants for metals in the final rule; EPA accounted for these
costs as part of its analysis of the economic impacts. Plants, however,
will also realize certain savings by no longer monitoring effluent that
would cease to exist under the final rule. The net changes in
monitoring and reporting are expected to be minimal, and EPA determined
that the existing burden estimates appropriately reflect any final rule
burden associated with monitoring.
    Based on the information in its record, EPA does not expect the
final rule to increase costs to permitting authorities. The rule will
not change permit application requirements or the associated review; it
will not increase the number of permits issued to steam electric power
plants; nor does it increase the efforts involved in developing or
reviewing such permits. In fact, the final rule will reduce the burden
to permitting authorities. In the absence of nationally applicable BAT
requirements, as appropriate, permitting authorities must establish
technology-based effluent limitations using BPJ to establish site-
specific requirements based on information submitted by the discharger.
Permitting authorities that establish technology-based effluent
limitations on a BPJ basis often spend significant time, effort, and
resources doing so, and dischargers may expend significant resources
providing associated data and information. Establishing nationally
applicable BAT requirements that eliminate the need to develop BPJ-
based limitations makes permitting easier and less costly in this
respect.
    As explained in Section XVI.A, under this rule, after the
permitting authority receives information from the discharger, it must
determine, on a facility-specific basis, what date is ``as soon as
possible'' during the period beginning November 1, 2018, and ending
December 31, 2023. This one-time burden to the discharger and the
permitting authority, however, is no more excessive than the existing
burden associated with developing technology-based effluent limitations
on a BPJ basis; in fact, it is very likely less burdensome.
Nevertheless, EPA conservatively estimated no net change (increase or
decrease) in the cost burden to federal or state governments or
dischargers associated with this final rule.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency
to prepare a regulatory flexibility analysis of any rule subject to
notice-and-comment rulemaking requirements under the Administrative
Procedure Act or any other statute, unless the agency certifies that
the rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
    I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. The
basis for this finding is documented in Chapter 8 of the RIA included
in the docket and summarized below. EPA estimates that 243 to 507
entities own steam electric power plants to which the ELGs apply, of
which 110 to 191 entities are small (see Table XVII-2).

             Table XVII-2--Number of Entities Owning Steam Electric Power Plants by Sector and Size
                                  [Assuming two different ownership cases] \a\
----------------------------------------------------------------------------------------------------------------
                                           Lower bound estimate of number of   Upper bound estimate of number of
                                            entities owning steam electric      entities owning steam electric
             Ownership type                        power plants \b\                    power plants \b\
                                         -----------------------------------------------------------------------
                                             Total     Small \c\    % Small      Total     Small \c\    % Small
----------------------------------------------------------------------------------------------------------------
Investor-Owned Utilities................          97          28        28.9         244          66        27.1
Nonutilities............................          36          19        52.8          77          35        46.1
Cooperatives............................          29          26        89.7          49          46        93.9
Municipality............................          65          36        55.4         101          43        42.1
Other Political Subdivision.............          12           1         8.3          30           1         3.3
Federal.................................           0           0         N/A           0           0         N/A
State...................................           2           0         0.0           2           0         0.0
Tribal..................................           0           0         N/A           0           0         N/A
                                         -----------------------------------------------------------------------
    All Entity Types....................         243         110        45.3         507         191        37.6
----------------------------------------------------------------------------------------------------------------
\a\ In 19 instances, a plant is owned by a joint venture of two entities; in one instance, the plant is owned by
  a joint venture of three entities.
\b\ Of these, 75 entities, 21 of which are small, own steam electric power plants that are expected to incur
  compliance costs under the final rule under both Case 1 and Case 2.
\c\ EPA was unable to determine size for 16 parent entities; for this analysis, these entities are assumed to be
  small.

    To assess whether small entities' compliance costs might constitute
a significant impact, EPA summed annualized compliance costs for the
steam electric power plants determined to be owned by a given small
entity and calculated these costs as a percentage of entity revenue
(cost-to-revenue test). EPA compared the resulting percentages to
impact criteria of one percent and three percent of revenue. Small
entities estimated to incur compliance costs exceeding one or more of
the one percent and three percent impact thresholds were identified as
potentially incurring a significant impact.
    EPA notes that setting the BAT limitations for FGD wastewater, fly
ash transport water, bottom ash transport water, FGMC wastewater, and
gasification wastewater equal to the BPT limitations on TSS in fly ash
transport water, bottom ash transport water, and low volume waste
sources at existing generating units with a total nameplate generating
capacity of 50 MW or less (as discussed in Section VIII.C.12) reduces
the potential impacts of the rule on small entities and municipalities.
The rulemaking record indicates that establishing a size threshold of
50 MW or less preferentially minimizes some of the expected economic
impacts on municipalities and small entities.
    Table XVII-3 presents the estimated numbers of small entities
incurring costs exceeding one percent and three percent of revenue, by
ownership type.

                 Table XVII-3--Estimated Cost-to-Revenue Impact on Small Entities Owning Steam Electric Power Plants, by Ownership Type
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Lower bound estimate of number of entities owning   Upper bound estimate of number of entities owning
                                                              steam electric power plants                         steam electric power plants
                                                 -------------------------------------------------------------------------------------------------------
                                                    Cost >=1% of revenue      Cost >=3% of revenue      Cost >=1% of revenue      Cost >=3% of revenue
                                                 -------------------------------------------------------------------------------------------------------
                                                                % of small   Number of    % of small                % of small   Number of    % of small
                                                   Number of     affected      small       affected    Number of     affected      small       affected
                                                     small       entities     entities     entities      small       entities     entities     entities
                                                    entities       \b\          \a\          \b\        entities       \b\          \a\          \b\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ownership Type..................................            Out of total 110 small entities
                                                            Out of total 191 small entities
                                                 -------------------------------------------------------------------------------------------------------
Cooperative.....................................            1          3.8            0          0.0            1          2.2            0          0.0
Investor-Owned..................................            0          0.0            0          0.0            0          0.0            0          0.0
Municipality....................................            4         11.1            1          2.8            4          9.4            1          2.3
Nonutility......................................            1          5.3            0          0.0            1          2.8            0          0.0
Other Political Subdivision.....................            0          0.0            0          0.0            0          0.0            0          0.0
                                                 -------------------------------------------------------------------------------------------------------
    Total.......................................            6          5.5            1          0.9            6          3.1            1          0.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The number of entities with cost-to-revenue ratios exceeding three percent is a subset of the number of entities with such ratios exceeding one
  percent.
\b\ Percentage values were calculated relative to the total of 110 (Case 1) and 191 (Case 2) small entities owning steam electric power plants. EPA
  expects that Case 2 is a more likely ownership scenario for small entities (e.g., small municipalities) as small entities may be less likely to own
  multiple non-surveyed steam electric power plants. See RIA Chapter 8 for details.

    As reported in Table XVII-3, EPA estimates that six small entities
owning steam electric power plants (one cooperative, one nonutility,
and four municipalities) will incur costs exceeding one percent of
revenue as a result of the final rule, and one small municipality
owning steam electric power plants will incur costs exceeding three
percent of revenue. The numbers of small entities incurring costs
exceeding either the one or three percent of revenue impact threshold
are small in the absolute and represent small percentages of the total
estimated number of small entities, which supports EPA's finding of no
significant impact on a substantial number of small entities (No
SISNOSE).

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2
U.S.C. 1531-1538, requires federal agencies, unless otherwise
prohibited by law, to assess the effects of their regulatory actions on
state, local, and tribal governments and the private sector. This
action contains a federal mandate that may result in expenditures of
$100 million or more (annually, adjusted for inflation) for state,
local, and tribal governments, in the aggregate, or the private sector
in any one year ($141 million in 2013). Accordingly, EPA prepared a
written statement required under section 202 of UMRA. The statement is
included in the docket for this action (see Chapter 9 in the RIA
report) and briefly summarized here.
    Consistent with the intergovernmental consultation provisions of
UMRA section 204, EPA consulted with governmental entities affected by
this rule. EPA described the government-to-government dialogue leading
to the proposed rule in its preamble to the proposed rulemaking. EPA
received comments from state and local government representatives in
response to the proposed rule and considered this input in developing
the final rule.