oEPA
Office of Water
United States	epa82i-f-19-004
Environmental Protection	M .
.	November 2019
Agency
Proposed Revisions to the Steam
Electric Effluent Guidelines
Summary
EPA is proposing revisions to the 2015 final rule's
effluent limits for flue gas desulfurization (FGD)
wastewater and for bottom ash (BA) transport water
applicable to existing steam electric power
generators to protect public health and the
environment by limiting wastewater discharges into
surface waters and wastewater treatment plants.
EPA's proposal would achieve pollution reductions
that are greater than the 2015 rule would have
achieved - to the tune of an estimated 105 million
pounds of lead, arsenic, mercury, and other
pollutants prevented from entering our nation's
waters annually.
This proposal would only revise the FGD wastewater
and BA transport water waste stream limits for
existing facilities and not limits for any other waste
streams covered by the 2015 rule. In the few years
since finalizing the 2015 rule, more affordable
technologies capable of removing a similar amount
of discharges have become available. The proposed
rule would make key changes to the 2015 rule,
including:
¦	Changing the technology-basis for treatment of
FGD wastewater and BA transport water, which
lowers costs for utilities and rate payers by using
newer pollutant control systems and providing
more flexibility in the operation and
maintenance of those systems.
¦	Revising the voluntary incentives program for
FGD wastewater to provide a lower cost option
and help reduce the amount of pollutants
discharged to our nation's waters by
approximately 105 million pounds per year.
¦ Adding subcategories for high-flow facilities, low
utilization units and facilities nearing retirement
to reduce costs for utilities and ratepayers by
imposing less stringent requirements.
The proposed modifications to the 2015 rule will
reduce compliance costs, saving approximately $175
million pre-tax annually, while also further reducing
the pollutant discharges over the 2015 rule. Cost
savings are primarily attributable to lower
technology costs associated with the pollutant
control systems available today to effectively treat
and manage the wastewater, flexibility in the
management of those systems, additional
subcategorization of affected power plants, and
establishing new compliance timeframes.
Who is affected by this regulation?
The Steam Electric Power Generating ELGs apply to a
major portion of the electric power industry, and the
proposed regulation would revise requirements
applicable to certain coal-fired steam electric power
plants.
What would the proposal require?
EPA took an open and inclusive approach to the
rulemaking process and considered a wide range of
data, information, and input. The agency also
conducted a limited information request and
collected voluntarily provided sampling data. Based
on this information, the proposed rule would
establish the following effluent limitations based on
Best Available Technology Economically Achievable
(BAT).

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¦	For the discharge of FGD wastewater, there are
two sets of BAT limitations: a numeric effluent
limitation on Total Suspended Solids (TSS); and
numeric effluent limitations on mercury, arsenic,
selenium, and nitrate/nitrite as nitrogen.
¦	For the discharge of BA transport water, there
are two sets of BAT limitations: a numeric
effluent limitation on TSS; and a not-too-exceed
10 percent volumetric purge limitation.
The proposed rule includes subcategories for high
flow facilities, low utilization boilers, and boilers
retiring by 2028. For high flow facilities or low
utilization boilers, the proposed rule would establish
numeric effluent limitations on mercury and arsenic
for FGD wastewater discharges. For low utilization
boilers, the proposed rule would establish numeric
limitations for TSS and would also require those
facilities to implement a best management practices
plan for BA transport water. For boilers retiring by
2028, the proposed rule would establish numeric
limitations for TSS in FGD wastewater and BA
transport water.
Where BAT limitations in this rule are more stringent
than previously established BPT limitations, EPA
proposes that those limitations do not apply until a
date determined by the permitting authority that is
as soon as possible on or after Nov. 1, 2020, but that
is no later than Dec. 31, 2023, (for BA transport
water) or Dec. 31, 2025 (for FGD wastewater).
The proposal also includes a voluntary incentives
program that provides the certainty of more time
(until Dec. 31, 2028) for plants to adopt additional
process changes and controls that achieve more
stringent limitations on mercury, arsenic, selenium,
nitrate/nitrite, bromide, and total dissolved solids in
FGD wastewater.
Background
Under the Clean Water Act, EPA establishes
regulations that apply to categories of industrial
wastewater dischargers. Known as Effluent
Limitations Guidelines and Pretreatment Standards,
these regulations are technology-based and protect
public health and the environment by limiting
wastewater discharges into surface waters and
wastewater treatment plants. EPA finalized a rule,
on Sept. 30, 2015, that provided ELGs for discharges
from steam electric power plants. That rule was
subject to legal challenge and the agency received
multiple petitions for administrative reconsideration,
including a request for reconsideration from the U.S.
Small Business Administration's Office of Advocacy.
In response, EPA announced the decision to
undertake a rulemaking to potentially revise the
new, more stringent BAT effluent limitations and
pretreatment standards for existing sources in the
2015 rule that apply to BA transport water and FGD
wastewater. This action contains the proposed
revisions.
Where can I find more information on this
proposal?
For technical information about the proposed rule,
contact Richard Benware by telephone at 202-566-
1369 or by email at benware.richard®epa.gov. For
economic information, contact James Covington by
telephone at 202-566-1034 or by email at
covington.iames(a)epa.gov. EPA will be accepting
written public comments on the proposed revisions
via Regulations.gov for 60 days upon publication of
the proposal in the Federal Register. EPA will
conduct a public hearing about the proposed rule
during the public comment period. The hearing will
be conducted online. Registration and additional
information is available on EPA's website at
https://www.epa.gov/eg/steam-electric-power-
generating-effluent-guidelines-2019-proposed-
revisions.

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