CHAPTER 16. ENVIRONMENTAL IMPACTS ANALYSIS
 

TABLE OF CONTENTS
 

16.1	 INTRODUCTION ......................................................................................................... 16-1
 

16.2	 AIR EMISSIONS ANALYSIS...................................................................................... 16-1
 

16.2.1 Air Emissions Descriptions.......................................................................... 16-1
 

16.2.2 Air Quality Regulation................................................................................. 16-4
 

16.2.3 Global Climate Change................................................................................ 16-5
 

16.2.4 Analytical Methods for Air Emissions ........................................................ 16-9
 

16.2.5 Effects on Power Plant Emissions ............................................................. 16-10
 

16.2.6 Effects on Site Emissions........................................................................... 16-13
 

16.2.7 Effects on Upstream Fuel-Cycle Emissions .............................................. 16-17
 

16.3	 WETLAND, ENDANGERED AND THREATENED SPECIES, AND
 

CULTURAL RESOURCES ........................................................................................ 16-18
 

16.4	 SOCIOECONOMIC IMPACTS.................................................................................. 16-18
 

16.5	 ENVIRONMENTAL JUSTICE IMPACTS................................................................ 16-19
 

16.6	 NOISE AND AESTHETICS ....................................................................................... 16-19
 

16.7	 SUMMARY OF ENVIRONMENTAL IMPACTS..................................................... 16-19
 

LIST OF TABLES 

Table 16.2.1 Impact of Residential Heating Products Efficiency Standards on 

Cumulative Energy-Related Emissions of CO2 between 2015 and 2045
 

(Million Metric Tons of CO2)............................................................................ 16-8
 

Table 16.2.2 Power Sector Emissions Forecast from AEO2009 Reference Case................. 16-10
 

Table 16.2.3 Power Sector Emissions Impact Forecasts for Water Heaters......................... 16-11
 

Table 16.2.4 Power Sector Emissions Impact Forecasts for Direct Heating Equipment...... 16-12
 

Table 16.2.5 Power Sector Emissions Impact Forecasts for Pool Heaters ........................... 16-13
 

Table 16.2.6 Change in Site Emissions for Water Heaters................................................... 16-15
 

Table 16.2.7 Change in Site Emissions from Direct Heating Equipment............................. 16-16
 

Table 16.2.8 Change in Site Emissions from Pool Heaters .................................................. 16-17
 

Table 16.2.9 Estimated Upstream Emissions of Air Pollutants as a Percentage of Direct
 

Power Plant Combustion Emissions ................................................................ 16-18
 

Table 16.7.1 Environmental Impact Analysis Results Summary for Water Heaters............ 16-20
 

Table 16.7.2 Environmental Impact Analysis Results Summary for Direct Heating
 

Equipment........................................................................................................ 16-20
 

Table 16.7.3 Environmental Impact Analysis Results Summary for Pool Heaters .............. 16-21
 

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CHAPTER 16. ENVIRONMENTAL IMPACTS ANALYSIS
 

16.1 INTRODUCTION
 

This chapter describes potential environmental effects that may result from amended 

energy conservation standards for residential heating products. The U.S. Department of Energy 

(DOE)’s proposed energy conservation standards are not site-specific, and would apply to all 50 

States and U.S. territories. Therefore, none of the proposed standards would impact land uses, 

cause any direct disturbance to the land, or directly affect biological resources in any one area. 

All of the trial standard levels (TSLs) are expected to reduce energy consumption in 

comparison to the base case. These changes in energy consumption are the primary drivers in 

analyzing environmental effects. The estimates of source energy savings that serve as inputs to 

the environmental assessment (EA) can be found in the utility impact analysis in chapter 13 of 

this technical support document (TSD). Detailed discussion on TSLs can be found in chapter 8 of 

this TSD. 

The primary impact of the TSLs is on air emissions resulting from power plant 

operations. Therefore, much of this chapter describes the air emissions analysis. The latter part of 

the chapter describes potential impacts to other environmental resources. Results reflect 

assumptions of medium economic growth (AEO2009 Reference Case); see appendix 16-A for 

high and low growth case scenarios. 

16.2 AIR EMISSIONS ANALYSIS 

A primary focus of the environmental analysis is the impact on air emissions of amended 

energy conservation standards for residential heating products. The outcomes of the 

environmental analysis are largely driven by changes in power plant types and quantities of 

electricity generated under each of the alternatives. Changes in generation are described in the 

utility impact analysis in chapter 13. 

16.2.1 Air Emissions Descriptions 

For each of the TSLs, DOE calculated total power-sector emissions based on output from 

the NEMS-BT model (see chapter 13 for description of the model). This analysis considers three 

pollutants: sulfur dioxide (SO2), nitrogen oxides (NOX), and mercury (Hg). An air pollutant is 

any substance in the air that can cause harm to humans or the environment. Pollutants may be 

natural or man-made (i.e., anthropogenic) and may take the form of solid particles (i.e., 

particulates or particulate matter), liquid droplets, or gases.a This analysis also considers carbon 

dioxide (CO2). 

a More information on air pollution characteristics and regulations is available on the U.S. Environment Protection 

Agent (EPA)’s website at www.epa.gov. 

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Sulfur Dioxide. Sulfur dioxide, or SO2, belongs to the family of sulfur oxide gases 

(SOx). These gases dissolve easily in water. Sulfur is prevalent in all raw materials, including 

crude oil, coal, and ore that contains common metals like aluminum, copper, zinc, lead, and iron. 

SOx gases are formed when fuel containing sulfur, such as coal and oil, is burned, and when 

gasoline is extracted from oil, or metals are extracted from ore. SO2 dissolves in water vapor to 

form acid, and interacts with other gases and particles in the air to form sulfates and other 

products that can be harmful to people and their environment.1 

DOE has preliminarily determined that SO2 emissions from affected Electric Generating 

Units (EGUs) are subject to nationwide and regional emissions cap and trading programs that 

create uncertainty about the proposed standards’ impact on SO2 emissions. Title IV of the Clean 

Air Act sets an annual emissions cap on SO2 for all affected EGUs. SO2 emissions from 28 

eastern States and the District of Columbia (D.C.) are also limited under the Clean Air Interstate 

Rule (CAIR, published in the Federal Register on May 12, 2005. 70 FR 25162 (May 12, 2005), 

which creates an allowance-based trading program that will gradually replace the Title IV 

program in those States and D.C. (The recent legal history surrounding CAIR is discussed 

below.) The attainment of the emissions caps is flexible among EGUs and is enforced through 

the use of emissions allowances and tradable permits. The standard could lead EGUs to trade 

allowances and increase SO2 emissions that offset some or all SO2 emissions reductions 

attributable to the standard. DOE is not certain that there will be reduced overall SO2 emissions 

from the standards. The NEMS-BT modeling system that DOE plans to use to forecast 

emissions reductions currently indicates that no physical reductions in power sector emissions 

would occur for SO2. However, remaining uncertainty prevents DOE from estimating SO2 

reductions from the standards at this time. 

Even though DOE is not certain that there will be reduced overall emissions from the 

standard, there may be an economic benefit from reduced demand for SO2 emission allowances. 

Electricity savings decrease the generation of SO2 emissions from power production, which can 

lessen the need to purchase SO2 emissions allowance credits, and thereby decrease the costs of 

complying with regulatory caps on emissions. 

Nitrogen Oxides. Nitrogen oxides, or NOX, is the generic term for a group of highly 

reactive gases, all of which contain nitrogen and oxygen in varying amounts. Many of the 

nitrogen oxides are colorless and odorless. However, one common pollutant, nitrogen dioxide 

(NO2), along with particles in the air can often be seen as a reddish-brown layer over many urban 

areas. NO2 is the specific form of NOX reported in this document. NOX is one of the main 

ingredients involved in the formation of ground-level ozone, which can trigger serious 

respiratory problems. It can contribute to the formation of acid rain, and can impair visibility in 

areas such as national parks. NOX also contributes to the formation of fine particles that can 

impair human health.1 

Nitrogen oxides form when fossil fuel is burned at high temperatures, as in a combustion 

process. The primary manmade sources of NOX are motor vehicles, electric utilities, and other 

industrial, commercial, and residential sources that burn fossil fuels. NOX can also be formed 

naturally. Electric utilities account for about 22 percent of NOX emissions in the United States.2 

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Mercury. Coal-fired power plants emit mercury (Hg) found in coal during the burning 

process. While coal-fired power plants are the largest remaining source of human-generated Hg 

emissions in the United States, they contribute very little to the global Hg pool or to 

contamination of U.S. waters.1 U.S. coal-fired power plants emit Hg in three different forms: 

oxidized Hg (likely to deposit within the United States); elemental Hg, which can travel 

thousands of miles before depositing to land and water; and Hg that is in particulate form. 

Atmospheric Hg is then deposited on land, lakes, rivers, and estuaries through rain, snow, and 

dry deposition. Once there, it can transform into methylmercury and accumulate in fish tissue 

through bioaccumulation. 

Americans are exposed to methylmercury primarily by eating contaminated fish. Because 

the developing fetus is the most sensitive to the toxic effects of methylmercury, women of 

childbearing age are regarded as the population of greatest concern. Children exposed to 

methylmercury before birth may be at increased risk of poor performance on neurobehavioral 

tasks, such as those measuring attention, fine motor function, language skills, visual-spatial 

abilities, and verbal memory.3 

Carbon Dioxide. Carbon dioxide (CO2) is not a criteria pollutant (see below), but it is of 

interest because of its classification as a greenhouse gas (GHG). GHGs trap the sun’s radiation 

inside the Earth’s atmosphere and either occur naturally in the atmosphere or result from human 

activities. Naturally occurring GHGs include water vapor, CO2, methane (CH4), nitrous oxide 

(N2O), and ozone (O3). Human activities, however, add to the levels of most of these naturally 

occurring gases. For example, CO2 is emitted to the atmosphere when solid waste, fossil fuels 

(oil, natural gas, and coal), wood, and wood products are burned. In 2007, over 90 percent of 

anthropogenic (i.e., human-made) CO2 emissions resulted from burning fossil fuels.4 

Concentrations of CO2 in the atmosphere are naturally regulated by numerous processes, 

collectively known as the “carbon cycle.” The movement of carbon between the atmosphere and 

the land and oceans is dominated by natural processes, such as plant photosynthesis. While these 

natural processes can absorb some of the anthropogenic CO2 emissions produced each year, 

billions of metric tons are added to the atmosphere annually. In the United States, in 2007, CO2 

emissions from electricity generation accounted for 39 percent of total U.S. GHG emissions.4 

Particulate Matter. Particulate matter (PM) also known as particle pollution, is a 

complex mixture of extremely small particles and liquid droplets. Particle pollution is made up 

of a number of components, including acids (such as nitrates and sulfates), organic chemicals, 

metals, and soil or dust particles. 

PM impacts are of concern due to human exposures that can impact health. Particle 

pollution - especially fine particles - contains microscopic solids or liquid droplets that are so 

small that they can get deep into the lungs and cause serious health problems. Numerous 

scientific studies have linked particle pollution exposure to a variety of problems, including: 

increased respiratory symptoms, such as irritation of the airways, coughing, or difficulty 

breathing, for example; decreased lung function; aggravated asthma; development of chronic 

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bronchitis; irregular heartbeat; nonfatal heart attacks; and premature death in people with heart or 

lung disease. 

Power plant emissions can have either direct or indirect impacts on PM. A portion of the 

pollutants emitted by a power plant are in the form of particulates as they leave the smoke stack. 

These are direct PM emissions. Meanwhile other pollutants such as SO2 and NOX interact with 

other elements in the atmosphere to produce PM at some distance from the power plant. 

In general, the relative impacts of direct PM emissions reduction compared to other 

pollutants on PM exposures are much more difficult to estimate than other emissions reductions. 

This is due to the complex interactions between PM, other power plant emissions, meteorology 

and atmospheric chemistry that impact human exposure to particulates. Human exposure to PM 

usually occurs at a significant distance from the power plants that are emitting particulates and 

particulate precursors. When power plant emissions travel this distance they undergo highly 

complex atmospheric chemical reactions and the proportion of impacts and exposures 

attributable to different emissions can vary dramatically for different emissions sources and types 

of particulate precursors. These variations in emissions impacts depend on the distance to the 

source, land use and land cover, and the local and regional meteorology responsible for pollutant 

transport, deposition and atmospheric chemistry. 

The Environmental Protection Agency (EPA) has compiled and summarized technical 

studies regarding PM source apportionment.5 In this compilation of studies, sources are 

classified into seven categories: (1) Secondary sulfate/coal, (2) Secondary organic matter/mobile 

sources, (3) Nitrate dominated sources, (4) Biomass burning, (5) Industrial, (6) Crustal and salt 

(7) Other. In these studies, the PM exposures attributed to coal power plants are not 

disaggregated between direct particulate emissions and SO2 emissions from these power plants. 

This is because both SO2 and direct PM emissions aggregate and interact with water droplets and 

emissions from other sources to create final particulates that are a complex mixture of different 

constituents. Both the SO2 and direct PM are emitted from the power plant at the same time and 

if the final aerosol particle contains both sulfur compounds and other PM components it is not 

possible to attribute that aerosol particle to one source or the other. Therefore, DOE is not 

currently able to perform modeling that can make reliable estimates of the impact of direct PM 

emissions on air quality at this time. 

16.2.2 Air Quality Regulation 

The Clean Air Act Amendments of 1990 list 188 toxic air pollutants that EPA is required 

to control.6 EPA has set national air quality standards for six common pollutants (also referred to 

as “criteria” pollutants), two of which are SO2 and NOX. Also, the Clean Air Act Amendments of 

1990 gave EPA the authority to control acidification and to require operators of electric power 

plants to reduce emissions of SO2 and NOX. Title IV of the 1990 amendments established a capand-trade program for SO2 intended to help control acid rain.6 This cap-and-trade program serves 

as a model for more recent programs with similar features. 

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In 2005, EPA issued the Clean Air Interstate Rule (CAIR) under sections 110 and 111 of 

the Clean Air Act (40 CFR Parts 51, 96, and 97).7 b CAIR will permanently cap emissions of SO2 

and NOX in eastern States of the United States. CAIR achieves large reductions of SO2 and/or 

NOX emissions across 28 eastern States and the District of Columbia. States must achieve the 

required emission reductions using one of two compliance options: 1) meet an emission budget 

for each regulated state by requiring power plants to participate in an EPA-administered 

interstate cap-and-trade system that caps emissions in two stages, or 2) meet an individual state 

emissions budget through measures of the state’s choosing. Phase 1 caps for NOX are to be in 

place in 2009. Phase 1 caps for SO2 are to be in place beginning in 2010. The Phase 2 caps for 

both NOX and SO2 are due in 2015. 

Also in 2005, EPA issued the final rule entitled “Standards of Performance for New and 

Existing Stationary Sources: Electric Steam Generating Units,” under sections 110 and 111 of 

the Clean Air Act (40 CFR Parts 60, 63, 72, and 75) 8

. This rule, called the Clean Air Mercury 

Rule (CAMR), was closely related to the CAIR and established standards of performance for Hg 

emissions from new and existing coal-fired electric utility steam generating units. The CAMR 

regulated Hg emissions from coal-fired power plants. 

On February 8, 2008, the U.S. Court of Appeals for the District of Columbia Circuit 

(D.C. Circuit) issued its decision in State of New Jersey, et al. v. Environmental Protection 

Agency,

c in which the Court, among other actions, vacated the CAMR referenced above. 

On July 11, 2008, the U.S. Court of Appeals for the District of Columbia Circuit (D.C. 

Circuit) issued its decision in North Carolina v. Environmental Protection Agency, which 

vacated the CAIR issued by the U.S. Environmental Protection Agency on March 10, 2005.d 

CAIR was the vehicle for capping NOX emissions. 

e On December 23, 2008, the D.C. Circuit 

decided to allow CAIR to remain in effect until it is replaced by a rule consistent with the court’s 

earlier opinion. North Carolina v. EPA, 550 F.3d 1176 (D.C. Cir. 2008) (remand of vacatur).f 

16.2.3 Global Climate Change 

Climate change has evolved into a matter of global concern because it is expected to have 

widespread, adverse effects on natural resources and systems. A growing body of evidence 

points to anthropogenic sources of greenhouse gases, such as carbon dioxide (CO2), as major 

contributors to climate change. Because this Rule, if finalized, will likely decrease CO2 emission 

rates from the fossil fuel sector in the United States, the Department here examines the impacts 

and causes of climate change and then the potential impact of the Rule on CO2 emissions and 

global warming. 

b See http://www.epa.gov/cleanairinterstaterule/. 

c No. 05-1097, 2008 WL 341338, at *1 (D.C. Cir. Feb. 8, 2008). 

d See http://www.epa.gov/cleanairinterstaterule/. 

e See id. at 903. 

f State of North Carolina, et al. v. Environmental Protection Agency, 550 F.3d 1176 (D.C. Cir. 2008). 

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Impacts of Climate Change on the Environment. Climate is usually defined as the 

average weather, over a period ranging from months to many years. Climate change refers to a 

change in the state of the climate, which is identifiable through changes in the mean and/or the 

variability of its properties (e.g., temperature or precipitation) over an extended period, typically 

decades or longer.9 

The World Meteorological Organization and United Nations Environment Programme 

(UNEP) established the Intergovernmental Panel on Climate Change (IPCC) to provide an 

objective source of information about climate change. According to the IPCC Fourth Assessment 

Report (IPCC Report), published in 2007, climate change is consistent with observed changes to 

the world’s natural systems; the IPCC expects these changes to continue.9 

Changes that are consistent with warming include warming of the world’s oceans to a 

depth of 3000 meters; global average sea level rise at an average rate of 1.8 mm per year from 

1961 to 2003; loss of annual average Arctic sea ice at a rate of 2.7 percent per decade, changes in 

wind patterns that affect extra-tropical storm tracks and temperature patterns, increases in intense 

precipitation in some parts of the world, as well as increased drought and more frequent heat 

waves in many locations worldwide, and numerous ecological changes.9 

Looking forward, the IPCC describes continued global warming of about 0.2 °C per 

decade for the next two decades under a wide range of emission scenarios for carbon dioxide 

(CO2), other greenhouse gases (GHGs), and aerosols. After that period, the rate of increase is 

less certain. The IPCC Report describes increases in average global temperatures of about 1.1 °C 

to 6.4 °C at the end of the century relative to today. These increases vary depending on the model 

9 and emissions scenarios.

The IPCC Report describes incremental impacts associated with the rise in temperature. 

At ranges of incremental increases to the global average temperature, IPCC reports, with either 

high or very high confidence, that there is likely to be an increasing degree of impacts such as 

coral reef bleaching, loss of wildlife habitat, loss to specific ecosystems, and negative yield 

impacts for major cereal crops in the tropics, but also projects that there likely will be some 

beneficial impacts on crop yields in temperate regions. 

Causes of Climate Change. The IPCC Report states that the world has warmed by about 

0.74 °C in the last 100 years. The IPCC Report finds that most of the temperature increase since 

the mid-20th century is very likely due to the increase in anthropogenic concentrations of CO2 

and other long-lived greenhouse gases such as methane and nitrous oxide in the atmosphere, 

rather than from natural causes. 

Increasing the CO2 concentration partially blocks the earth’s re-radiation of captured 

solar energy in the infrared band, inhibits the radiant cooling of the earth, and thereby alters the 

energy balance of the planet, which gradually increases its average temperature. The IPCC 

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Report estimates that currently, CO2 makes up about 77 percent of the total CO2-equivalentg 

global warming potential in GHGs emitted from human activities, with the vast majority (74 

percent) of the CO2 attributable to fossil fuel use.10 For the future, the IPCC Report describes a 

wide range of GHG emissions scenarios, but under each scenario CO2 would continue to 

comprise above 70 percent of the total global warming potential.10 

Stabilization of CO2 Concentrations. Unlike many traditional air pollutants, CO2 mixes 

thoroughly in the entire atmosphere and is long-lived. The residence time of CO2 in the 

atmosphere is long compared to the emission processes. Therefore, the global cumulative 

emissions of CO2 over long periods determine CO2 concentrations because it takes hundreds of 

years for natural processes to remove the CO2. Globally, 49 billion metric tons of CO2 – 

equivalent of anthropogenic (man-made) greenhouse gases are emitted every year. Of this annual 

total, fossil fuels contribute about 29 billion metric tons of CO2.

11 h 

Researchers have focused on considering atmospheric CO2 concentrations that likely will 

result in some level of global climate stabilization, and the emission rates associated with 

achieving the “stabilizing” concentrations by particular dates. They associate these stabilized 

CO2 concentrations with temperature increases that plateau in a defined range. For example, at 

the low end, the IPCC Report scenarios target CO2 stabilized concentrations range between 350 

ppm and 400 ppm (essentially today’s value)—because of climate inertia, concentrations in this 

low-end range would still result in temperatures projected to increase 2.0 °C to 2.4 °C above preindustrial levelsi (about 1.3 °C to 1.7 °C above today’s levels). To achieve concentrations 

between 350 ppm to 400 ppm, the IPCC scenarios present that there would have to be a rapid 

downward trend in total annual global emissions of greenhouse gases to levels that are 50 to 85 

percent below today’s annual emission rates by no later than 2050. Since it is assumed that there 

would continue to be growth in global population and substantial increases in economic 

production, the scenarios identify required reductions in greenhouse gas emissions intensity 

(emissions per unit of output) of more than 90 percent. However, even at these rates, the 

scenarios describe some warming and some climate change is projected due to already 

accumulated CO2 and GHGs in the atmosphere.12 

The Beneficial Impact of the Rule on CO2 Emissions. If finalized, it is anticipated that 

the Rule will reduce energy-related CO2 emissions, particularly those associated with energy 

consumption in buildings. The U.S. Energy Information Administration (EIA) reports in its 2009 

Annual Energy Outlook (AEO2009)

13 that U.S. annual energy-related emissions of CO2 in 2006 

were about 6.0 billion metric tons, of which 1.2 billion tons were attributed to the residential 

g GHGs differ in their warming influence (radiative forcing) on a global climate system due to their different 

radiative properties and lifetimes in the atmosphere. These warming influences may be expressed through a common 

metric based on the radiative forcing of CO2, i.e., CO2-equivalent. CO2 equivalent emission is the amount of CO2 

emission that would cause the same- time integrated radiative forcing, over a given time horizon, as an emitted 

amount of other long- lived GHG or mixture of GHGs. 

h Other non-fossil fuel contributors include CO2 emissions from deforestation and decay from agriculture biomass; 

agricultural and industrial emissions of methane; and emissions of nitrous oxide and fluorocarbons. 

i IPCC Working Group 3 Table TS 2 

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buildings sector (including related energy–using products such as residential heating products). 

Most of the greenhouse gas emissions attributed to residential buildings are emitted from fossil 

fuel-fired power plants that generate electricity used in this sector. In the AEO2009 Reference 

Case, EIA projected that annual energy-related CO2 emissions would grow from 5.7 billion 

metric tons in 2010 to 6.2 billion metric tons in 2030, an increase of 8 percent (see AEO2009), 

while residential emissions would grow to from 1.2 billion metric tons to 1.3 billion metric tons, 

an increase of 5 percent. 

The estimated cumulative CO2 emission reductions from a residential heating product 

efficiency standard (shown as a range of alternative TSLs) during this same 30-year period are 

indicated in Table 16.2.1. Estimated CO2 emission reductions in Table 16.2.1 come from two 

sources: electricity generation (i.e., power plants) and fossil fuel-fired appliances. The estimated 

CO2 emission reductions from electricity generation are calculated using the NEMS-BT model. 

The estimated CO2 emission reductions from fossil fuel-fired appliances (i.e., gas heating 

products) are derived from emissions factors for residential natural gas combustion. 

Table 16.2.1 Impact of Residential Heating Products Efficiency Standards on 

Cumulative Energy-Related Emissions of CO2 between 2015 and 2045 

(Million Metric Tons of CO2) 

Trial Standard Levels 

TSL 1 TSL 2 TSL 3 TSL 4 TSL 5 TSL 6 TSL 7 

Water Heaters* -88.7 -136.8 -146.6 -153.8 -217.5 -345.8 -965.5 

TSL 1 TSL 2 TSL 3 TSL 4 TSL 5 TSL 6 

Direct Heating Equipment* -6.32 -7.02 -8.52 -16.69 -18.46 -42.97 

Pool Heaters* -0.61 -1.05 -3.31 -4.21 -5.74 -12.12 

Total* -95.6 -144.9 -158.4 -174.7 -804.5 -1,021 

Percent of Total Cumulative 

Emissions Reduction in 2015­

2045 compared with the 

AEO2009 Reference Case 

-0.124 -0.188 -0.206 -0.227 -0.481 -1.326 

* All results in million metric tons, equivalent to 1.1 short tons; negative values refer to a reduction compared with 

the base case. 

The Incremental Impact of the Rule on Climate Change. It is difficult to correlate 

specific emission rates with atmospheric concentrations of CO2 and specific atmospheric 

concentrations with future temperatures because the IPCC Report describes a clear lag in the 

climate system between any given concentration of CO2 (even if maintained for long periods) 

and the subsequent average worldwide and regional temperature, precipitation, and extreme 

weather regimes. For example, a major determinant of climate response is “equilibrium climate 

sensitivity”, a measure of the climate system response to sustained radioactive forcing. It is 

defined as the global average surface warming following a doubling of carbon dioxide 

concentrations. The IPCC Report describes its estimated, numeric value as about 3 °C, but the 

likely range of that value is 2 °C to 4.5 °C, with cloud feedbacks the largest source of 

uncertainty. Further, as illustrated above, the IPCC Report scenarios for stabilization rates are 

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presented in terms of a range of concentrations, which then correlates to a range of temperature 

changes. Thus, climate sensitivity is a key uncertainty for CO2 mitigation scenarios that aim to 

meet specific temperature levels. 

Because of how complex global climate systems are, it is difficult to know to what extent 

and when particular CO2 emissions reductions will impact global warming. However, as Table 

16.2.1 indicates, the proposed rule is expected to reduce CO2 emissions associated with energy 

consumption in buildings. 

16.2.4 Analytical Methods for Air Emissions 

NEMS-BT incorporates capabilities to assess compliance with SO2 restrictions specified 

in the Clean Air Act and its amendments. Clean Air Act provisions include New Source 

Performance Standards, and Revised New Source Performance Standards. The version of 

NEMS-BT in 2008 included provisions for the CAIR, which imposes stricter restrictions on SO2 

and NOX for some states, and the CAMR, which imposed a national Hg constraint. As discussed 

earlier is section 16.2.2, on December 23, 2008, the D.C. Circuit decided to allow CAIR to 

remain in effect until it is replaced by a rule consistent with the court’s earlier opinion. Carolina 

v. Environmental Protection Agency, 550 F.3d 1176 (D.C. Cir. 2008) (remand of vacatur). But 

actions taken on February 8, 2008 by the U.S. Court of Appeals for the District of Columbia 

Circuit (D.C. Circuit) issued in its decision in State of New Jersey, et al. v. Environmental 

Protection Agency, remain in effect vacating the CAMR. Thus, the version of NEMS-BT used in 

this analysis does not include provisions for the CAMR. 

Coal-fired electric generation is the single largest source of electricity in the United 

States. Because the mix of coals used significantly affects the emissions produced, the model 

includes a detailed representation of coal supply. The model considers the rank of the coal as 

well as the sulfur contents of the fuel used when determining optimal dispatch.14 

Within the NEMS-BT model, planning options for achieving emissions restrictions in the 

Clean Air Act Amendments include installing pollution control equipment on existing power 

plants and building new power plants with low emission rates. These methods for reducing 

emission are compared to dispatching options such as fuel switching and allowance trading. 

Environmental regulations also affect capacity expansion decisions. For instance, new plants are 

not allocated SO2 emissions allowances according to the Clean Air Act Amendments. 

Consequently, the decision to build a particular capacity type must consider the cost (if any) of 

obtaining sufficient allowances. This could involve purchasing allowances or over complying at 

an existing unit. 

DOE’s analysis assumed the presence of nationwide emission caps on SO2 and caps on 

NOX emissions in the 28 States covered by the CAIR. The NEMS-BT modeling system that 

DOE plans to use to forecast emissions reductions currently indicates that no physical reductions 

in power sector emissions would occur for SO2. However, remaining uncertainty prevents DOE 

from estimating or reporting SO2 reductions from energy conservation standards at this time. It 

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should be noted that the standards could put slight downward pressure on the prices of emissions 

allowances in cap-and-trade markets. 

In contrast to the modeling forecasts of NEMS-BT that SO2 emissions reductions will 

remain at the cap, during the years 2007 and 2008, SO2 emissions have been below the trading 

cap. The difference between the emissions levels that NEMS-BT forecasts and those that EPA 

forecasts is an indicator of the uncertainties associated with long-range energy sector forecasts. 

As noted in chapter 13, NEMS-BT model forecasts end in year 2030. Emissions impacts 

beyond 2030 were assumed to be equal to the impacts in 2030. 

16.2.5 Effects on Power Plant Emissions 

Table 16.2.2 shows AEO2009 reference case power plant emissions in selected years. 

The Reference Case emissions are the emissions shown by the NEMS-BT model to result if none 

of the TSLs are promulgated (the base case). 

Table 16.2.2 Power Sector Emissions Forecast from AEO2009 Reference Case 

NEMS-BT Results* 

2005 2010 2015 2020 2025 2030 

CO2 (Million metric tons/year)** 2,397 2,343 2,381 2,466 2,535 2,636 

NOX (Million metric tons/year)† 3.30 2.08 1.87 1.88 1.88 1.91 

Hg (metric tons/year)† 51.5 43.8 29.5 28.9 29.3 28.7 

* All results in metric tons, equivalent to 1.1 short tons and negative values refer to a reduction compared with 

the Base Case 

** Comparable to Table A17 of AEO2009: Electric Generators 

† Comparable to Table A8 of AEO2009: Emissions 

Table 16.2.3 through Table 16.2.5 show the estimated changes in power plant emissions 

in selected years for each of the TSLs. Changes in CO2, NOX, and Hg emissions from power 

plants are shown in these tables. 

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Table 16.2.3 Power Sector Emissions Impact Forecasts for Water Heaters
 

NEMS-BT Results* Difference from AEO2009 Reference Case 

2010 2015 2020 2025 2030 2035 2040 2044 

Extrapolation 

2015-2045 

Standard Level 1 

CO2 (Mt/a) 0.03 -0.21 -1.00 -1.68 -1.79 -1.79 -1.79 -1.79 -45.96 

NOx (kt/a) 0.02 -0.16 -0.76 -1.25 -1.29 -1.29 -1.29 -1.29 -33.70 

Hg (t/a) -0.001 -0.004 0.001 -0.008 0.000 0.000 0.000 0.000 -0.108 

Standard Level 2 

CO2 (Mt/a) 0.04 -0.32 -1.52 -2.56 -2.71 -2.71 -2.71 -2.71 -69.76 

NOx (kt/a) 0.04 -0.25 -1.16 -1.90 -1.96 -1.96 -1.96 -1.96 -51.15 

Hg (t/a) -0.001 -0.006 0.002 -0.012 0.000 0.000 0.000 0.000 -0.164 

Standard Level 3 

CO2 (Mt/a) 0.05 -0.36 -1.72 -2.91 -3.08 -3.08 -3.08 -3.08 -79.24 

NOx (kt/a) 0.04 -0.28 -1.31 -2.15 -2.23 -2.23 -2.23 -2.23 -58.10 

Hg (t/a) -0.001 -0.007 0.002 -0.014 0.000 0.000 0.000 0.000 -0.186 

Standard Level 4 

CO2 (Mt/a) 0.05 -0.39 -1.87 -3.17 -3.37 -3.37 -3.37 -3.37 -86.52 

NOx (kt/a) 0.04 -0.30 -1.43 -2.35 -2.43 -2.43 -2.43 -2.43 -63.44 

Hg (t/a) -0.002 -0.007 0.002 -0.015 0.000 0.000 0.000 0.000 -0.203 

Standard Level 5 

CO2 (Mt/a) -0.19 0.66 -2.75 -5.35 -5.94 -5.94 -5.94 -5.94 -142 

NOx (kt/a) -0.17 0.52 -2.10 -3.97 -4.29 -4.29 -4.29 -4.29 -104 

Hg (t/a) -0.010 -0.015 -0.010 -0.030 -0.012 -0.012 -0.012 -0.012 -0.603 

Standard Level 6 

CO2 (Mt/a) 0.25 2.59 -6.07 -12.7 -14.0 -14.0 -14.0 -14.0 -328 

NOx (kt/a) 0.22 2.04 -4.62 -9.43 -10.13 -10.13 -10.13 -10.13 -240 

Hg (t/a) 0.023 -0.038 -0.040 -0.099 -0.059 -0.059 -0.059 -0.059 -2.18 

Standard Level 7 

CO2 (Mt/a) 0.51 5.31 -12.35 -25.80 -28.57 -28.57 -28.57 -28.57 -668 

NOx (kt/a) 0.45 4.17 -9.41 -19.11 -20.65 -20.65 -20.65 -20.65 -487 

Hg (t/a) 0.046 -0.077 -0.081 -0.201 -0.119 -0.119 -0.119 -0.119 -4.43 

*All results in metric tons (t), equivalent to 1.1 short tons 

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Table 16.2.4 Power Sector Emissions Impact Forecasts for Direct Heating Equipment
 

NEMS-BT Results Difference from AEO2009 Reference Case 

2010 2015 2020 2025 2030 2035 2040 2042 

Extrapolation Total 

2013-2043 

Standard Level 1 

CO2 (Mt/a) 0.002 0.023 0.032 0.089 0.115 0.115 0.115 0.115 2.38 

NOx (kt/a) 0.002 0.018 0.025 0.066 0.083 0.083 0.083 0.083 1.74 

Hg (t/a) -0.001 0.000 0.000 0.000 0.002 0.002 0.002 0.002 0.018 

Standard Level 2 

CO2 (Mt/a) 0.003 0.026 0.036 0.100 0.129 0.129 0.129 0.129 2.66 

NOx (kt/a) 0.002 0.020 0.027 0.074 0.093 0.093 0.093 0.093 1.95 

Hg (t/a) -0.001 0.001 0.000 0.000 0.002 0.002 0.002 0.002 0.020 

Standard Level 3 

CO2 (Mt/a) 0.003 0.031 0.044 0.122 0.159 0.159 0.159 0.159 3.28 

NOx (kt/a) 0.003 0.025 0.033 0.090 0.115 0.115 0.115 0.115 2.40 

Hg (t/a) -0.001 0.001 0.000 -0.001 0.003 0.003 0.003 0.003 0.024 

Standard Level 4 

CO2 (Mt/a) 0.003 0.040 0.075 0.245 0.318 0.318 0.318 0.318 6.44 

NOx (kt/a) 0.003 0.031 0.057 0.181 0.230 0.230 0.230 0.230 4.70 

Hg (t/a) 0.000 -0.002 0.000 -0.002 0.002 0.002 0.002 0.002 0.005 

Standard Level 5 

CO2 (Mt/a) 0.003 0.044 0.082 0.270 0.351 0.351 0.351 0.351 7.11 

NOx (kt/a) 0.003 0.034 0.063 0.200 0.254 0.254 0.254 0.254 5.19 

Hg (t/a) 0.000 -0.002 -0.001 -0.003 0.002 0.002 0.002 0.002 0.005 

Standard Level 6 

CO2 (Mt/a) 0.008 0.106 0.200 0.652 0.843 0.843 0.843 0.843 17.11 

NOx (kt/a) 0.007 0.084 0.152 0.483 0.610 0.610 0.610 0.610 12.50 

Hg (t/a) 0.000 -0.004 -0.001 -0.006 0.006 0.006 0.006 0.006 0.012 

*All results in metric tons (t), equivalent to 1.1 short tons 

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Table 16.2.5 Power Sector Emissions Impact Forecasts for Pool Heaters
 

NEMS-BT Results* Difference from AEO2009 Reference Case 

2010 2015 2020 2025 2030 2035 2040 2042 

Extrapolation Total 

2013-2043 

Standard Level 1 

CO2 (Mt/a) 0.000 0.002 0.004 0.005 0.009 0.009 0.009 0.009 0.177 

NOx (kt/a) 0.000 0.002 0.003 0.004 0.006 0.006 0.006 0.006 0.130 

Hg (t/a) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.001 

Standard Level 2 

CO2 (Mt/a) 0.000 0.004 0.006 0.008 0.015 0.015 0.015 0.015 0.305 

NOx (kt/a) 0.000 0.003 0.005 0.006 0.011 0.011 0.011 0.011 0.223 

Hg (t/a) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.002 

Standard Level 3 

CO2 (Mt/a) 0.001 0.012 0.020 0.026 0.048 0.048 0.048 0.048 0.947 

NOx (kt/a) 0.001 0.010 0.015 0.019 0.035 0.035 0.035 0.035 0.693 

Hg (t/a) 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 -0.005 

Standard Level 4 

CO2 (Mt/a) 0.001 0.009 0.018 0.029 0.041 0.041 0.041 0.041 0.837 

NOx (kt/a) 0.001 0.007 0.014 0.021 0.030 0.030 0.030 0.030 0.612 

Hg (t/a) 0.000 0.000 0.000 0.000 0.001 0.001 0.001 0.001 0.001 

Standard Level 5 

CO2 (Mt/a) 0.001 0.012 0.025 0.040 0.056 0.056 0.056 0.056 1.14 

NOx (kt/a) 0.001 0.010 0.019 0.029 0.041 0.041 0.041 0.041 0.837 

Hg (t/a) 0.000 0.000 0.000 -0.001 0.001 0.001 0.001 0.001 0.001 

Standard Level 6 

CO2 (Mt/a) 0.002 0.026 0.052 0.084 0.120 0.120 0.120 0.120 2.43 

NOx (kt/a) 0.002 0.021 0.040 0.062 0.086 0.086 0.086 0.086 1.78 

Hg (t/a) 0.000 0.000 0.000 -0.001 0.002 0.002 0.002 0.002 0.002 

*All results in metric tons (t), equivalent to 1.1 short tons 

16.2.6 Effects on Site Emissions 

For residential heating products, DOE also accounts for impacts on household emissions 

at the site (i.e., the residential building). NEMS-BT does not account for these emissions at the 

site. The estimates given here are based on exogenous emissions factors for residential natural 

gas combustion derived by the EPA’s AP-42 report, in conjunction with the site energy savings 

15 predicted by the national impacts analysis (NIA) model.

The emissions factors DOE used are derived from what is reported in the AP-42 for 

residential water heaters because no explicit listing was provided for the other heating products. 

Given that emissions rates from end-use combustion are small compared to other emissions 

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sources, it is not uncommon to see emissions factors from residential end uses reported in one 

general rate.16 For these reasons, the Department opted to simply use the water heating emissions 

factor for all of the heating products. It acknowledges that these estimates are only general 

approximations. 

Tables 16.2.6 through 16.2.8 show the estimated changes in site emissions in selected 

years for each of the water heater, direct heating equipment, and pool heater TSLs. 

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Table 16.2.6 Change in Site Emissions for Water Heaters
 

2010 2015 2020 2025 2030 2035 2040 2044 

Extrapolation Total 

2015-2045 

Standard Level 1 

CO2 (Mt/a) 0.00 -0.15 -0.90 -1.49 -1.77 -1.77 -1.77 -1.77 -42.73 

NOx (kt/a) 0.00 -0.12 -0.73 -1.22 -1.44 -1.44 -1.44 -1.44 -34.84 

SO2 (kt/a) 0.000 -0.006 -0.037 -0.062 -0.074 -0.074 -0.074 -0.074 -1.78 

Standard Level 2 

CO2 (Mt/a) 0.00 -0.24 -1.42 -2.35 -2.77 -2.77 -2.77 -2.77 -67.03 

NOx (kt/a) 0.00 -0.20 -1.16 -1.91 -2.26 -2.26 -2.26 -2.26 -54.65 

SO2 (kt/a) 0.000 -0.010 -0.060 -0.100 -0.118 -0.118 -0.118 -0.118 -2.85 

Standard Level 3 

CO2 (Mt/a) 0.00 -0.24 -1.43 -2.36 -2.78 -2.78 -2.78 -2.78 -67.31 

NOx (kt/a) 0.00 -0.20 -1.16 -1.92 -2.27 -2.27 -2.27 -2.27 -54.88 

SO2 (kt/a) 0.000 -0.013 -0.079 -0.132 -0.155 -0.155 -0.155 -0.155 -3.75 

Standard Level 4 

CO2 (Mt/a) 0.00 -0.24 -1.43 -2.36 -2.78 -2.78 -2.78 -2.78 -67.31 

NOx (kt/a) 0.00 -0.20 -1.16 -1.92 -2.27 -2.27 -2.27 -2.27 -54.88 

SO2 (kt/a) 0.000 -0.013 -0.079 -0.132 -0.155 -0.155 -0.155 -0.155 -3.75 

Standard Level 5 

CO2 (Mt/a) 0.00 -0.27 -1.59 -2.63 -3.10 -3.10 -3.10 -3.10 -75.14 

NOx (kt/a) 0.00 -0.22 -1.30 -2.15 -2.53 -2.53 -2.53 -2.53 -61.26 

SO2 (kt/a) 0.000 -0.013 -0.080 -0.134 -0.158 -0.158 -0.158 -0.158 -3.82 

Standard Level 6 

CO2 (Mt/a) 0.00 -0.08 -0.44 -0.65 -0.69 -0.69 -0.69 -0.69 -17.60 

NOx (kt/a) 0.00 -0.07 -0.36 -0.53 -0.56 -0.56 -0.56 -0.56 -14.34 

SO2 (kt/a) 0.000 -0.012 -0.070 -0.116 -0.136 -0.136 -0.136 -0.136 -3.30 

Standard Level 7 

CO2 (Mt/a) 0.00 -1.06 -6.24 -10.34 -12.36 -12.36 -12.36 -12.36 -298 

NOx (kt/a) 0.00 -0.86 -5.09 -8.43 -10.08 -10.08 -10.08 -10.08 -243 

SO2 (kt/a) 0.000 -0.021 -0.123 -0.205 -0.243 -0.243 -0.243 -0.243 -5.86 

*All results in metric tons (t), equivalent to 1.1 short tons 

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Table 16.2.7 Change in Site Emissions from Direct Heating Equipment
 

2010 2015 2020 2025 2030 2035 2040 2042 

Extrapolation Total 

2013-2043 

Standard Level 1 

CO2 (Mt/a) 0.000 -0.083 -0.219 -0.338 -0.368 -0.368 -0.368 -0.368 -8.70 

NOx (kt/a) 0.000 -0.072 -0.190 -0.293 -0.318 -0.318 -0.318 -0.318 -7.53 

SO2 (kt/a) 0.000 -0.002 -0.006 -0.009 -0.010 -0.010 -0.010 -0.010 -0.240 

Standard Level 2 

CO2 (Mt/a) 0.000 -0.092 -0.243 -0.376 -0.410 -0.410 -0.410 -0.410 -9.68 

NOx (kt/a) 0.000 -0.080 -0.210 -0.324 -0.354 -0.354 -0.354 -0.354 -8.36 

SO2 (kt/a) 0.000 -0.002 -0.007 -0.010 -0.011 -0.011 -0.011 -0.011 -0.260 

Standard Level 3 

CO2 (Mt/a) 0.000 -0.111 -0.293 -0.456 -0.502 -0.502 -0.502 -0.502 -11.80 

NOx (kt/a) 0.000 -0.096 -0.252 -0.392 -0.431 -0.431 -0.431 -0.431 -10.14 

SO2 (kt/a) 0.000 -0.003 -0.007 -0.012 -0.013 -0.013 -0.013 -0.013 -0.298 

Standard Level 4 

CO2 (Mt/a) 0.000 -0.220 -0.579 -0.897 -0.981 -0.981 -0.981 -0.981 -23.13 

NOx (kt/a) 0.000 -0.190 -0.500 -0.774 -0.846 -0.846 -0.846 -0.846 -19.95 

SO2 (kt/a) 0.000 -0.006 -0.015 -0.024 -0.026 -0.026 -0.026 -0.026 -0.612 

Standard Level 5 

CO2 (Mt/a) 0.000 -0.242 -0.637 -0.990 -1.086 -1.086 -1.086 -1.086 -25.56 

NOx (kt/a) 0.000 -0.210 -0.552 -0.857 -0.939 -0.939 -0.939 -0.939 -22.12 

SO2 (kt/a) 0.000 -0.007 -0.018 -0.027 -0.030 -0.030 -0.030 -0.030 -0.701 

Standard Level 6 

CO2 (Mt/a) 0.000 -0.575 -1.510 -2.334 -2.543 -2.543 -2.543 -2.543 -60.08 

NOx (kt/a) 0.000 -0.498 -1.309 -2.022 -2.202 -2.202 -2.202 -2.202 -52.04 

SO2 (kt/a) 0.000 -0.016 -0.042 -0.065 -0.071 -0.071 -0.071 -0.071 -1.67 

*All results in metric tons (t), equivalent to 1.1 short tons 

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Table 16.2.8 Change in Site Emissions from Pool Heaters
 

2010 2015 2020 2025 2030 2035 2040 2042 

Extrapolation Total 

2013-2043 

Standard Level 1 

CO2 (Mt/a) 0.000 -0.011 -0.026 -0.030 -0.031 -0.031 -0.031 -0.031 -0.788 

NOx (kt/a) 0.000 -0.009 -0.022 -0.026 -0.026 -0.026 -0.026 -0.026 -0.680 

SO2 (kt/a) 0.000 0.000 -0.001 -0.001 -0.001 -0.001 -0.001 -0.001 -0.021 

Standard Level 2 

CO2 (Mt/a) 0.000 -0.019 -0.044 -0.052 -0.052 -0.052 -0.052 -0.052 -1.35 

NOx (kt/a) 0.000 -0.016 -0.038 -0.045 -0.045 -0.045 -0.045 -0.045 -1.17 

SO2 (kt/a) 0.000 -0.001 -0.001 -0.001 -0.001 -0.001 -0.001 -0.001 -0.036 

Standard Level 3 

CO2 (Mt/a) 0.000 -0.059 -0.139 -0.162 -0.165 -0.165 -0.165 -0.165 -4.26 

NOx (kt/a) 0.000 -0.051 -0.120 -0.140 -0.142 -0.142 -0.142 -0.142 -3.67 

SO2 (kt/a) 0.000 -0.002 -0.004 -0.004 -0.004 -0.004 -0.004 -0.004 -0.113 

Standard Level 4 

CO2 (Mt/a) 0.000 -0.070 -0.165 -0.192 -0.196 -0.196 -0.196 -0.196 -5.05 

NOx (kt/a) 0.000 -0.061 -0.142 -0.166 -0.169 -0.169 -0.169 -0.169 -4.35 

SO2 (kt/a) 0.000 -0.002 -0.004 -0.005 -0.005 -0.005 -0.005 -0.005 -0.134 

Standard Level 5 

CO2 (Mt/a) 0.000 -0.096 -0.224 -0.262 -0.267 -0.267 -0.267 -0.267 -6.88 

NOx (kt/a) 0.000 -0.083 -0.194 -0.226 -0.230 -0.230 -0.230 -0.230 -5.94 

SO2 (kt/a) 0.000 -0.003 -0.006 -0.007 -0.007 -0.007 -0.007 -0.007 -0.182 

Standard Level 6 

CO2 (Mt/a) 0.000 -0.203 -0.474 -0.555 -0.563 -0.563 -0.563 -0.563 -14.54 

NOx (kt/a) 0.000 -0.175 -0.409 -0.479 -0.486 -0.486 -0.486 -0.486 -12.55 

SO2 (kt/a) 0.000 -0.005 -0.013 -0.015 -0.015 -0.015 -0.015 -0.015 -0.385 

*All results in metric tons (t), equivalent to 1.1 short tons 

16.2.7 Effects on Upstream Fuel-Cycle Emissions 

Upstream fuel-cycle emissions refer to the emissions associated with the amount of 

energy used in the upstream production and downstream consumption of electricity, including 

energy used at the power plant.17 Upstream processes include the mining of coal or extraction of 

natural gas, physical preparatory and cleaning processes, and transportation to the power plant. 

The NEMS-BT does a thorough accounting of emissions at the power plant due to downstream 

energy consumption, but does not account for upstream emissions (i.e., emissions from energy 

losses during coal and natural gas production). Thus, this analysis reports only power plant 

emissions. 

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However, previous DOE environmental assessment documents have developed 

approximate estimates of effects on upstream fuel-cycle emissions. These emissions factors 

provide the reader with a sense of the possible magnitude of upstream effects. These upstream 

emissions would be in addition to emissions from direct combustion. 

Relative to the entire fuel cycle, estimates based on the work of Dr. Mark DeLuchi, and 

reported in earlier DOE environmental assessment documents, find that an amount 

approximately equal to eight percent, by mass, of emissions (including SO2) from coal 

production are due to mining, preparation that includes cleaning the coal, and transportation from 

the mine to the power plant.18 Transportation emissions include emissions from the fuel used by 

the mode of transportation that moves the coal from the mine to the power plant. In addition, 

based on Dr. DeLuchi’s work, DOE estimated that an amount equal to approximately 14 percent 

of emissions from natural gas production result from upstream processes. 

Emission factor estimates and corresponding percentages of contributions of upstream 

emissions from coal and natural gas production, relative to power plant emissions, are shown in 

Table 16.2.9 for CO2 and NOX. The percentages provide a means to estimate upstream emission 

savings based on changes in emissions from power plants. This approach does not address Hg 

emissions. 

Table 16.2.9	 Estimated Upstream Emissions of Air Pollutants as a Percentage of 

Direct Power Plant Combustion Emissions 

Pollutant 

Percent of Coal 

Combustion Emissions 

Percent of Natural Gas 

Combustion Emissions 

CO2 2.7 11.9 

NOX 5.8 40 

16.3	 WETLAND, ENDANGERED AND THREATENED SPECIES, AND 

CULTURAL RESOURCES 

Because residential heating products are not water-consuming products, more efficient 

heating would not reduce the amount of water discharged into the waste stream. As a result, 

heating product energy conservation standards do not have the effect of improving the quality of 

wetlands, nor threatened or endangered species that reside in these wetlands. This action is also 

not expected to impact cultural resources such as historical or archaeological sites. 

16.4	 SOCIOECONOMIC IMPACTS 

DOE's analysis has shown that the increase in the first cost of purchasing more efficient 

water heaters, direct heating equipment, and pool heaters at the proposed standard levels is 

completely offset by a reduction in the life-cycle cost (LCC) of owning a more efficient product 

for the average consumer. In other words, the consumer will pay less operating costs over the life 

of the product even through the first cost increases. The complete LCC analysis and its 

conclusions are presented in chapter 8 of the TSD. 

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For subgroups of low-income and senior consumers that purchase heating products, DOE 

determined that the average LCC impact of the proposed standards is similar to that for the full 

sample of consumers. Therefore, DOE concludes that the proposed action would have no 

significant adverse socioeconomic impact. For a complete discussion on the LCC impacts on 

consumer subgroups, see chapter 11 of the TSD. 

16.5 ENVIRONMENTAL JUSTICE IMPACTS 

In view of Executive Order 12898 of February 11, 1994, “Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income Populations,” DOE examined 

the effect of the proposed energy conservation standards on low-income households. As 

described in the LCC subgroup analysis in Chapter 11 of the TSD, DOE found that there were no 

disproportionately high and adverse human health or environmental effects on low-income 

populations that would result from the proposed energy conservation standards. 

16.6 NOISE AND AESTHETICS 

Improvements in efficiency of heating products are expected to result from changes in the 

choice of components and other design features. These changes are described in chapter 5 of this 

TSD. These design changes are not expected to change noise levels in comparison to products in 

today’s market. Products that are currently manufactured in the existing market that would meet 

the proposed standards are no louder than less efficient products. Changes to the design to 

improve the efficiency levels are not anticipated to affect the product aesthetics. 

16.7 SUMMARY OF ENVIRONMENTAL IMPACTS 

Tables 16.7.1 through 16.7.3 summarize the estimated environmental impacts for each of 

the TSLs. The summary tables show cumulative changes in emissions for CO2, NOX, and Hg for 

2015 to 2045 for water heaters and from 2013 to 2043 for direct heating equipment and pool 

heaters. 

For direct heating equipment and pool heaters, cumulative CO2, NOX, and Hg emissions 

from the power sector show a slight increase under some TSLs compared to the Reference case. 

This result is primarily due to an increase in electricity use at the considered TSLs. The moreefficient DHE products and pool heaters save natural gas, but they also use more electricity due 

to electronic ignition and, for some DHE TSLs, use of a fan (see section 7.3.6 and section 7.4.4 

in chapter 7). This results in higher electricity generation than in the Reference case, which leads 

to higher emissions. For CO2 and NOX, the higher emissions from the power sector are more 

than canceled out by lower household emissions from gas combustion, such that total emissions 

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decrease under the considered TSLs. For Hg, this is not the case because there are no offsetting 

household emissions.j 

Upstream fuel cycle emission of CO2 and NOX are described but not quantified in section 

16.2.7. The text describes potential reductions in fuel cycle emissions as percentage of decreases 

in power plant emissions. This approach suggests that upstream fuel cycle emissions would 

decrease and provides a sense for the magnitude of effects; however DOE does not report actual 

estimates of the effects. 

For subgroups of low-income and senior consumers that purchase heating products, DOE 

determined that the average LCC impact of the proposed standards is similar to that for the full 

sample of consumers. Therefore, DOE concludes that the proposed action would have no 

significant adverse socioeconomic impact. 

No impacts are anticipated in the areas of environmental justice, wetlands, endangered 

and threatened species, and cultural resources; or noise and aesthetics. 

Table 16.7.1	 Environmental Impact Analysis Results Summary for Water Heaters 

Environmental Effects 

Reference 

Case* 

Trial Standard Level 

1 2 3 4 5 6 7 

Cumulative Total Emission Reductions** 

CO2 (million metric tons) 76,950 88.7 137 147 154 217 346 966 

NOX (thousand tons) 56,763 68.5 106 113 118 165 254 730 

Hg (tons) 866 0.11 0.16 0.19 0.20 0.60 2.18 4.43 

Cumulative Power Sector Emission Reductions** 

CO2 (million metric tons) 76,950 46.0 69.8 79.2 86.5 142 328 668 

NOX (thousand tons) 56,763 33.7 51.2 58.1 63.4 104 240 487 

Hg (tons) 866 0.11 0.16 0.19 0.20 0.60 2.18 4.43 

Cumulative Household Emission Reductions** 

CO2 (million metric tons) - 42.7 67.0 67.3 67.3 75.1 17.60 298 

NOX (thousand tons) - 34.8 54.7 54.9 54.9 61.3 14.34 243 

* The reference case reflects total cumulative emissions (power sector only) in the absence of an amended energy 

conservation standard. 

** Cumulative total is over 2015 to 2045 for water heaters. 

Table 16.7.2	 Environmental Impact Analysis Results Summary for Direct Heating 

Equipment 

Environmental Effects 

Reference 

Case* 

Trial Standard Level 

1 2 3 4 5 6 

Cumulative Total Emission Reductions** 

CO2 (million metric tons) 76,445 6.32 7.02 8.52 16.69 18.46 42.97 

NOX (thousand tons) 57,080 5.79 6.42 7.74 15.25 16.93 39.55 

j For DHE, the estimated increase in Hg emissions under the proposed standard (TSL 3) amounts to 24 kg over 30 

years). For pool heaters, the estimated increase in Hg emissions under the proposed standard (TSL 4) amounts to 

only 1 kg over 30 years (see Table 16.7.2). 

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Environmental Effects 

Reference 

Case* 

Trial Standard Level 

1 2 3 4 5 6 

Hg (tons) 895 (0.018) (0.020) (0.024) (0.005) (0.005) (0.012) 

Cumulative Power Sector Emission Reductions** 

CO2 (million metric tons) 76,445 (2.38) (2.66) (3.28) (6.44) (7.11) (17.11) 

NOX (thousand tons) 57,080 (1.74) (1.95) (2.40) (4.70) (5.19) (12.50) 

Hg (tons) 895 (0.018) (0.020) (0.024) (0.005) (0.005) (0.012) 

Cumulative Household Emission Reductions** 

CO2 (million metric tons) - 8.70 9.68 11.80 23.13 25.56 60.08 

NOX (thousand tons) - 7.53 8.36 10.14 19.95 22.12 52.04 

* The reference case reflects total cumulative emissions (power sector only) in the absence of an amended energy 

conservation standard. 

** Cumulative total is over 2013 to 2043 for direct heating equipment. Values in parentheses refer to emissions increase. 

Table 16.7.3 Environmental Impact Analysis Results Summary for Pool Heaters 

Environmental Effects 

Reference 

Case* 

Trial Standard Level 

1 2 3 4 5 6 

Cumulative Total Emission Reductions** 

CO2 (Million metric tons) 76,445 0.61 1.05 3.31 4.21 5.74 12.12 

NOX (Thousand tons) 57,080 0.550 0.944 2.98 3.74 5.10 10.77 

Hg (tons) 895 0.001 0.002 0.005 (0.001) (0.001) (0.002) 

Cumulative Power Sector Emission Reductions** 

CO2 (Million metric tons) 76,445 (0.177) (0.305) (0.947) (0.837) (1.14) (2.43) 

NOX (Thousand tons) 57,080 (0.130) (0.223) (0.693) (0.612) (0.837) (1.78) 

Hg (tons) 895 0.001 0.002 0.005 (0.001) (0.001) (0.002) 

Cumulative Household Emission Reductions** 

CO2 (Million metric tons) - 0.788 1.35 4.26 5.05 6.88 14.54 

NOX (Thousand tons) - 0.680 1.17 3.67 4.35 5.94 12.55 

* The reference case reflects total cumulative emissions (power sector only) in the absence of an amended energy 

conservation standard. 

** Cumulative total is over 2013 to 2043 for pool heaters. Values in parentheses refer to emissions increase. 

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