Waste and Materials-Flow Benchmark Sector Report:
Beneficial Use of Secondary Materials -
Coal Combustion Products
Economics, Methods, and Risk Analysis Division
Office of Solid Waste
Office of Solid Waste and Emergency Response
U.S. Environmental Protection Agency
Washington, D.C. 20460
Final Report
February 12, 2008
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ACKNOWLEDGMENTS
Industrial Economics, Incorporated (IEc), is responsible for the overall organization and development of
this report. This report was developed with the assistance of Dr. H. Scott Mathews of the Carnegie
Mellon Green Design Institute, Dr. Jim Boyd of Resources for the Future, Dave Goss of the American
Coal Ash Association (ACAA), and with input and data from various EPA Office of Solid Waste and
Office of Policy Economics and Innovation representatives. Lyn D. Luben of the U.S. Environmental
Protection Agency, Office of Solid Waste, provided guidance and review.
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TABLE OF CONTENTS
EXECUTIVE SUMMARY ES-1
CHAPTER 1: INTRODUCTION 1-1
Overview of the Report 1-2
Organization of Report 1-2
CHAPTER 2: BASELINE CHARACTERIZATION OF CCP GENERATION AND
BENEFICIAL USE 2-1
Current Quantities of CCPs Generated Managed 2-2
Beneficial Use Options 2-5
CHAPTER 3: MARKET STRUCTURE OF BENEFICIAL USE FOR CCPs 3-1
Coal-Fired Utility Practices: CCP Supply 3-1
Intermediaries 3-3
tind-Users Purchaser's: CCP Demand 3-3
Market Dynamics of Specific Use Applications 3-5
Concrete 3-7
Gypsum Wai I board 3-8
Fill 3-8
Impacts of Current Policy Setting on Market Dynamics 3-8
CHAPTER 4: IMPACTS ASSOCIATED WITH BENEFICIAL USE OF CCPs 4-1
Life Cycle Analvsis and RCC Program Outcomes 4-1
Life Cycle Analysis Economic Benefit Assessment 4-1
Assessment of Beneficial Impacts of CCP Use 4-3
Methodology for Evaluating Unit Impacts of Beneficial Use 4-5
BEES Analysis of Use of Fly Ash in Concrete 4-5
SimaPro Analysis of FGD Gypsum in Wallboard 4-6
Allocation of Life Cycle Impacts to CCPs 4-7
Results 4-8
Limitations Assumptions 4-10
CHAPTER 5: ESTIMATING PROGRAM LEVEL IMPACTS 5-1
Development of Defensible Beneficial Use Scenarios 5-1
Current Market Dynamics: Factors Affecting Beneficial Use 5-1
Structural Changes to the Market 5-3
Attribution of Impacts to EPA Programs 5-3
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Beneficial Associated with Current Use of CCPS 5-5
Economic Distribution of CCP Beneficial Use 5-8
Conclusions Next Steps 5-8
REFERENCES R-1
APPENDIX A: KEY BENEFICIAL USE APPLICATIONS FOR CCPS
APPENDIX B: USE OF LIFE CYCLE ANALYSIS IN EVALUATION OF ECONOMIC BENEFITS
APPENDIX C: ANALYSIS OF BENEFITS USING ALTERNATE LIFE CYCLE MODELS
APPENDIX D: DETAILS OF LIFE CYCLE ANALYSIS METHODOLOGIES
APPENDIX E: POTENTIAL IMPACTS OF ALLOCATION OF LCI RESULTS TO CCPS
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EXECUTIVE SUMMARY
INTRODUCTION
The U.S. Environmental Protection Agency's Office of Solid Waste (EPA OSW) is currently developing
methods to evaluate the environmental, human health, and economic outcomes of specific EPA programs.
As an initial step, OSW is examining the extent to which the costs and benefits of source reduction, reuse,
and recycling may be quantified for a range of materials targeted by the Resource Conservation Challenge
(RCC).
Coal combustion products (CCPs) are among the materials targeted by EPA's Resource Conservation
Challenge (RCC). The RCC is designed to facilitate changes in the economics and practice of waste
generation, handling, and disposal (e.g., by promoting market opportunities for beneficial use). Under the
RCC, EPA has established three goals for increased beneficial use of CCPs:
Achieve a 50 percent beneficial use rate of CCPs by 2011;
Increase the use of coal fly ash in concrete by 50 percent (from 12.4 million tons per year in 2001
to 18.6 million tons by 2011); and
Reduce greenhouse gas emissions from concrete production by approximately 5 million metric
tons CO2 equivalent by 2010.:
CCPs are formed during coal-burning processes in power plants and industrial boilers. Coal combustion
produces various forms of CCPs, which are categorized by the process in which they are generated.
Common CCPs include: fly ash, bottom ash, Flue Gas Desulphurization (FGD) material, boiler slag,
Fluidized Bed Combustion (FBC) ash, and cenospheres. CCPs may be beneficially used as a component
of building materials or as a replacement for other virgin materials such as sand, gravel, or gypsum. Size,
shape, and chemical composition determine the suitability of these materials for beneficial use. Higher
value applications, such as use in cement or concrete products, require moderately stringent specifications
(in terms of size, shape and chemical composition), whereas lower value uses, such as structural or
mining fills, can accept more variable materials.
This report serves two purposes: (1) To provide an initial assessment of the market dynamics that affect
the generation, disposal, recovery, and beneficial use of CCPs; and (2) to provide a preliminary life cycle
analysis of the beneficial impacts of CCP use, including an initial estimate of the baseline beneficial use
impacts with current (2005) CCP levels and, for some materials, the beneficial impacts associated with
achieving the 2011 RCC goal.
CCP GENERATION AND MARKET DYNAMICS
The American Coal Ash Association (ACAA), a trade association whose purpose is to advance the
beneficial use of CCPs, reports that the electric power industry generates approximately 123 million short
tons of CCPs annually. Of these, the industry disposed of approximately 74 million short tons to
landfills, while beneficially using approximately 50 million short tons in products.2 Exhibit ES-1
summarizes results of the most recent (2005) ACAA survey of generators of CCPs, which indicates that
1 U.S. EPA, "About Cin," accessed at http://www.epa.gov/epaoswer/osw/conserve/c2p2/about/about.htm.
2The ACAA survey is administered to both ACAA members and non-members. ACAA members account for approximately 40 percent of private
power generation. Not all survey recipients complete the survey each year. ACAA extrapolates survey respondent data to the entire coal-fired
electricity generation industry.
ES-1
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the most common beneficial use applications for CCPs are as a replacement for virgin materials in
concrete and cement-making, structural fill, and gypsum wallboard.
EXHIBIT ES-1: ACAA SURVEY OF KEY BENEFICIAL USE APPLICATIONS FOR CCPS IN 2005 (MILLION
SHORT TONS)
APPLICATION
(INDUSTRY)
Concrete8
(Construction)
Structural fillb
(Construction)
Wallboarcf
(Construction)
Raw feed for
cement clinkerd
(Construction)
Waste stabilization6
(Waste Mgmt)
Blasting
Grit/Roofing
Granules
Total - Key Uses
Total - Other
Uses'
TOTAL - ALL USES
COAL FLY
ASH
14.99
5.71
0
2.83
2.66
0
26.19
2.93
29.12
BOTTOM
ASH
1.02
2.32
0
0.94
0.04
0.89
4.41
3.13
7.54
FGD
GYPSUM
0.33
0
8.18
0.40
0
0
8.90
0.36
9.27
OTHER
FGD WET
MATERIAL
0
0
0
< 0.01
0
0
< o.or
0.69
0.69
FGD DRY
MATERIAL
0.01
< 0.01
0
0
0
0
0.02
0.074
0.16
BOILER
SLAG
0
0.18
0
0.04
0
1.54
1.76
0.13
1.89
FBC ASH
0
0.14
0
0
0.14
0
0.28
0.66
0.94
TOTAL
16.35
8.35
8.18
4.22
2.84
1.63
41.57
8.04
49.61
2005 QUANTITY
GENERATED
71.10
17.60
12.00
17.70
1.43
1.96
1.37
123. 13g
CCP UTILIZATION
RATEh
41%
43%
77%
4%
11%
97%
69%
40%
Notes:
a. CCPs are frequently used as a replacement for a portion of portland cement in the manufacture of concrete.
b. Structural fill is an engineered material that is used to raise or change the surface contour of an area and to provide
ground support beneath highway roadbeds, pavements and building foundations. It can also be used to form
embankments.
c. FGD gypsum is used as a substitute for virgin gypsum in wallboard manufacturing.
d. CCPs can be blended with limestone or shale and fed into the cement kiln to make clinker, which is then ground into
Portland cement.
e. The chemical properties of CCPs make them effective stabilizers of biosolids (i.e., sludge from municipal waste water
treatment).
f. Includes quantities beneficially used in minor applications not included in this exhibit, but listed in Appendix A.
g. Includes 115,596 tons of "Other FGD Material" not listed in this table because of the small quantities generated.
h. CCP utilization rates reflect all use applications, some of which are omitted from this table but are included in Appendix
A. Utilization rates are calculated by dividing the total quantity used by the total quantity generated.
Note: Results from the 2006 CCP Production and Use Survey conducted by the ACAA indicate a total utilization rate of 43.43
percent, up from 40.29 percent reported for 2005. This reflects an ongoing upward trend in the CCP utilization rate over the
past decade. The 2006 results were received too late for incorporation into this report.
Sources:
1. American Coal Ash Association. "2005 Coal Combustion Product (CCP) Production and Use Survey," accessed at:
http://www.acaa-usa.org/PDF/20045_CCP_Production_and_Use_Figures_Released_by _ACAA.pdf.
2. Western Region Ash Group, "Applications and Competing Materials, Coal Combustion Byproducts," accessed at:
http://www.wrashg.org/compmat.htm.
ES-2
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The CCP beneficial use market is composed of three primary segments. These are:
Generators: Approximately 400 to 500 coal-fired electric utilities currently operate in the
United States. Since the coal power industry consumes approximately 92% of all U.S. coal, it is
responsible for producing the vast majority of CCPs in the country. Other industries that use coal
as a fuel source in commercial or industrial boilers (e.g., mineral and grain processors) also
produce small quantities of CCPs. Several factors influence a generator's decision to either
dispose or seek beneficial use options for spent CCPs. Key considerations include the costs of
landfill disposal, transport, processing, storage, and marketing.
Intermediaries: Some coal-fired utilities market CCPs for beneficial use through a third-party
instead of selling directly to users. In these cases, a utility perceives an efficiency in outsourcing
the marketing of its CCPs. Marketers typically accept all of a generator's CCPs as a service to the
company, sell the marketable portion, and dispose of the portion that is not salable. The marketer
typically bears the cost of hauling CCPs from the utility and the liability associated with moving
or storing the materials.
End-Users: Several economic factors determine an end-user's decision to use CCPs in its
product. These factors include: the price of CCPs relative to the price of virgin materials for
specific uses; the technical fit between CCPs and the use application; access to sufficient
quantities of CCPs; and federal and state policies associated with CCP use.
Impacts of Current Policy Setting on Market Dynamics
While states play a primary role in establishing industrial waste regulations and guidance, EPA has an
opportunity to provide coordination and assistance at the national and regional level to help achieve a
shift in waste management policy. EPA is currently engaged in several partnerships to facilitate and
increase beneficial use of CCPs. Efforts within these partnerships include: promoting the beneficial use
of CCPs through the development of web resources; developing technical guidance on the best practices
for the beneficial use of CCPs; holding educational workshops and outreach support for CCP users; and
providing recognition for the innovative beneficial use of CCPs. Key partners in these efforts include the
American Coal Ash Association (ACAA), Utility Solid Waste Group (USWAG), the U.S. Department of
Energy (DOE), and the Federal Highway Administration (FHWA).
ESTIMATING THE IMPACTS OF THE BENEFICIAL USE OF CCPS
To quantify the environmental impacts of increased beneficial use of CCPs in various applications, we
use a life cycle analysis approach, as both a first step in an economic analysis, and, where economic
analysis is not practical, as a meaningful proxy.
To estimate beneficial impacts of CCP use, we first develop preliminary estimates of the incremental
impacts associated with using a specific quantity (e.g., one ton) of CCPs in different applications. These
impacts can then be extrapolated in specific scenarios designed to address program-level outcomes. To
fully capture the beneficial impacts of EPA program achievements, it is necessary to model each
beneficial use application of all CCPs targeted by the RCC. However, the time, data, and resources
required to perform this task are beyond the scope of this report. For this preliminary analysis, therefore,
we have selected two common CCPs, fly ash and FGD gypsum, whose beneficial use applications are
well understood, and for which life cycle models and existing data are available.
ES-3
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We conduct separate analyses to evaluate the incremental environmental impacts associated with
beneficially using a specific quantity (e.g., one ton) of fly ash and FGD gypsum. We selected two life
cycle modeling applications, Building for Environmental and Economic Sustainability (BEES) and
SimaPro, to conduct the analyses. Both models have been peer-reviewed and evaluate a large suite of
environmental metrics. We employ the BEES model to investigate the beneficial impacts of using one
ton of fly ash as a substitute for finished portland cement in concrete, and SimaPro to evaluate the use of
one ton of FGD gypsum as a substitute for virgin gypsum in wallboard. Both analyses assume that the
beneficial use material (fly ash or FGD gypsum) substitutes for virgin material (finished portland cement
or virgin gypsum) on a one-to-one, mass-based basis. Exhibit ES-2 presents the results of the BEES and
SimaPro analysis.
EXHIBIT ES-2: INCREMENTAL BENEFICIAL IMPACTS OF USING FLY ASH IN PORTLAND CEMENT AND
FGD GYPSUM IN WALLBOARD
AVOIDED IMPACTS
ENERGY USE
NONRENEWABLE ENERGY (MJ)"
RENEWABLE ENERGY (Mjf
TOTAL PRIMARY ENERGY (MJ)
TOTAL PRIMARY ENERGY (US$f
WATER USE
TOTAL WATER USE (L)
TOTAL WATER USE (US$f'
GREENHOUSE GAS EMISSIONS
CO;, (G)
METHANE (G)
AIR EMISSIONS
CO (G)
NOX (G)
SOX (G)
P ARTICULATES GREATER THAN PM,n (G)
P ARTICULATES LESS THAN OR EQUAL TO PMln (G)
P ARTICULATES UNSPECIFIED (G)
MERCURY (G)
LEAD (G)
WATERBORNE WASTES
SUSPENDED MATTER (G)
BIOLOGICAL OXYGEN DEMAND (G)
PER1 TON FLY ASH AS
PORTLAND CEMENT
SUBSTITUTE IN CONCRETE
4,214.18
43.55
4,259.29
119.26
341.56
0.22
636,170.21
539.49
593.45
1,932.48
1,518.21
0.00
0.01
1,745.25
0.04
0.03
13.96
3.07
PER 1 TON FGD GYPSUM IN
WALLBOARD
12,568.97
13.69
12,582.66
352.31
14,214.60
9.01
77,754.24
175.51
39.06
168.02
139.14
1,194.25
520.93
17.11
0.00
0.03
23.60
21.87
ES-4
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AVOIDED IMPACTS
PER1 TON FLY ASH AS
PORTLAND CEMENT
SUBSTITUTE IN CONCRETE
PER 1 TON FGD GYPSUM IN
WALLBOARD
:HEMICAL OXYGEN (G)
IOPPER (G)
(G)
LEAD (G)
(G)
NONHAZARDOUS WASTE (KG)e
26.00
0.00
0.00
0.00
0.00
0.00
24.71
0.02
0.00
0.01
0.00
3.12
Notes:
a. Nonrenewable energy refers to energy derived from fossil fuels such as coal, natural gas and oil.
b. Renewable energy refers to energy derived from renewable sources, but BEES does not specify what sources
these include.
In addition to reporting energy impacts in megajoules (MJ), we monetize impacts by multiplying model
outputs in MJ by the average cost of electricity in 2006 ($0.0275/MJ), converted to 2007 dollars
($0.0280/MJ). The 2006 cost of energy is taken from the Federal Register, February 27, 2006, accessed at:
http://www.npga.org/14a/pages/index.cfm?pageid=914. The cost was converted to 2007 dollars using
NASA's Gross Domestic Product Deflator Inflation Calculator, accessed at:
http://cost.isc.nasa.gov/inflateGDP.html.
In addition to reporting water impacts in gallons, we monetize impacts by converting model outputs from
liters to gallons and multiplying by the average cost per gallon of water between July 2004 and July 2005
($0.0023/gal), converted to 2007 dollars ($0.0024/gal). The 2005 cost of water is taken from NUS Consulting
Group, accessed at: https://www.energyvortex.com/files/NUS_quick_click.pdf. The cost was converted to
2007 dollars using NASA's Gross Domestic Product Deflator Inflation Calculator, accessed at:
http://cost.isc.nasa.gov/inflateGDP.html.
BEES reports waste as "end of life waste." In contrast, SimaPro reports "solid waste." It is not clear if these
waste metrics are directly comparable as SimaPro does not specify whether "solid waste" refers to
manufacturing waste, end-of-life waste, or both.
d.
The results of the fly ash and FGD gypsum analyses suggest many positive environmental impacts from
beneficial use. For most metrics, there is a significant difference between the unit impact value for fly ash
and FGD gypsum. The difference in unit impact values reflects different avoided processes when fly ash
is used to offset portland cement versus when FGD gypsum is used to offset virgin gypsum. For example,
the primary driver of benefits when fly ash is used in concrete is avoided raw materials extraction and
avoided portland cement production.3 In comparison, the primary driver of benefits when FGD gypsum is
used in wallboard is avoided virgin gypsum extraction and the processing of virgin gypsum into stucco.
Portland cement production generates relatively high greenhouse gas emissions. Thus, the avoided CO2
and methane emissions are greater for fly ash than for FGD gypsum in this analysis. In contrast, gypsum
mining requires comparatively higher quantities of water, so the water savings are greater for FGD
gypsum in this analysis than for portland cement. In addition, the difference in unit impacts likely reflects
minor differences in the system boundaries in each analysis and the data sets utilized by each model.
ESTIMATING PROGRAM LEVEL IMPACTS
In order to extrapolate the beneficial impacts presented in Exhibit ES-2 to evaluate EPA's program level
efforts, two critical steps are necessary.
Development of defensible beneficial use scenarios that accurately identify the extent to which
different beneficial uses are likely to increase; and
3 It is unclear from the documentation provided for BEES what impacts (e.g. virgin materials extraction, plant infrastructure, etc.) are modeled for
portland cement production. For this reason, it is not possible to explain the differences in unit impact results between the FGD gypsum and fly
ash analysis.
ES-5
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Implementation of a well-supported attribution protocol for assigning beneficial use impacts to
specific EPA programs.
At this time, the data necessary to develop accurate beneficial use scenarios and to support a clear
attribution of impacts are not sufficient to inform a detailed program analysis. In the absence of such
data, we present a preliminary analysis of the total impacts associated with current (baseline) beneficial
use patterns. While these impacts do not strictly reflect RCC program achievements, they represent the
best available information on the environmental benefits of beneficially using certain CCPs, and reflect
the impacts of all EPA, state, and industry efforts to increase CCP use to its 2005 level. The beneficial
use impacts of current fly ash and FGD gypsum use are calculated by extrapolating the impacts identified
in Exhibit ES-3 to the current quantity of each material beneficially used in each application. For fly ash,
we also extrapolate the beneficial impacts associated with achieving the 2011 RCC goala 50% increase
in fly ash use in concrete. Exhibit ES-3 presents the key impacts of the beneficial use of CCPs
extrapolated to current use quantities. Note that the impacts presented in Exhibit ES-3 represent only a
partial estimate of the total impacts of beneficially using CCPs. Beneficial use of fly ash as a substitute
for finished portland cement in concrete and FGD gypsum in wallboard accounts for only 47% (23.2
million tons) of all beneficially used CCPs in 2005.
EXHIBIT ES-3: EXTRAPOLATED IMPACTS OF THE BENEFICIAL USE OF CCPs
AVOIDED IMPACTS
ENERGY USE
(MJf
(MJ)f
TOTAL (MJ)
(US$)9
FLY ASH IN
CONCRETE
EXTRAPOLATED
TO RCC GOAL
(18. 6 MILLION
TONS)3
78.4 billion
810.0 million
79.2 billion
$2.2 billion
FLY ASH IN
CONCRETE
EXTRAPOLATED
TO CURRENT
USE (15.0
MILLION TONS)"
63.2 billion
652.8 million
63.8 billion
$1 .8 billion
FGD GYPSUM IN
WALLBAORD
EXTAPOLATED
TO CURRENT
USE (8.2
MILLION TONS)C
102. 8 billion
111.9 million
102.9 billion
$2.9 billion
PARTIAL SUM OF
CURRENT USE
BENEFICIAL
IMPACTS"
166.0 billion
764.7 million
166. 7 billion
$4.7 billion
WATER USE
TOTAL USE
TOTAL USE (US$)h
6.3 billion
$4.0 million
5.2 billion
$3.2 million
116.2 billion
$73.7 million
121 .4 billion
$77.9 million
GREENHOUSE GAS EMISSIONS
CO, (G)
(G)
CO 2
11.8 trillion
10.0 billion
13.2 million
9.5 trillion
8.1 billion
10.6 million
0.6 trillion
1 .4 billion
0.7 million
10.2 trillion
9.5 billion
11.5 million
AIR EMISSIONS
CO (G)
NOic (G)
$0x (G)
11.0 billion
35.9 billion
28.2 billion
8.9 billion
29.0 billion
22.8 billion
0.3 billion
1 .4 billion
1.1 billion
9.2 billion
30.3 billion
23.9 billion
ES-6
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AVOIDED IMPACTS
FLY ASH IN
CONCRETE
EXTRAPOLATED
TO RCC GOAL
(18.6 MILLION
TONS)3
FLY ASH IN
CONCRETE
EXTRAPOLATED
TO CURRENT
USE (15.0
MILLION TONS)"
FGD GYPSUM IN
WALLBAORD
EXTAPOLATED
TO CURRENT
USE (8.2
MILLION TONS)C
PARTIAL SUM OF
CURRENT USE
BENEFICIAL
IMPACTS"
PM10 (G)
LESS THAN OR TO PM,0 (G)
PARTICULATES UNSPECIFIED (G)
MERCURY (G)
(G)
WATERBORNE WASTES
CHEMICAL (G)
(G)
NON-HAZARDOUS WASTE (KG)J
Notes:
0.2 million
32.5 billion
714,000
523,000
259.6 million
57.1 million
483.6 million
.02 million
26.1 billion
576,000
421,000
209.2 million
46.1 million
389.7 million
9.7 billion
4.3 million
0.1 billion
8,000
235,000
193.0 million
178.8 million
202.1 million
194,000
3,000
65,000
2,000
25.4 million
9.7 billion
4.3 million
26.3 billion
584,000
656,000
402.2 million
1224.9 million
591.8 million
194,000
3,000
65,000
2,000
25.4 million
a. We extrapolate the incremental impacts (i.e., impacts associated with use of 1 ton fly ash) to estimate impacts of attaining the
RCC goal for the use of fly ash in concrete (18.6 million tons by 2011). To extrapolate, we multiply each of the incremental impacts
calculated by the BEES model by 18.6 million.
b. We extrapolate the incremental impacts (i.e., impacts associated with use of 1 ton fly ash) to estimate the impacts of current
beneficial use of fly ash in concrete (15.0 million tons). The current quantity of fly ash that is beneficially used as a substitute for
finished portland cement in concrete is reported by ACAA's 2005 CCP Survey. We multiply each of the incremental impacts
calculated by BEES by 15.0 million tons to extrapolate these impacts to reflect current use.
c. We extrapolate the incremental impacts (i.e., impacts associated with use of 1 ton FGD gypsum) to estimate the impacts of current
beneficial use of FGD gypsum in wallboard (8.2 million tons). The current quantity of FGD gypsum that is beneficially used as a
substitute for finished portland cement in concrete is reported by ACAA's 2005 CCP Survey. We multiply each of the incremental
impacts calculated by SimaPro by 8.2 million to extrapolate these impacts to reflect current use.
d. Calculated as the sum of the fly ash and FGD gypsum current use extrapolations.
e. Nonrenewable energy refers to energy derived from fossil fuels such as coal, natural gas and oil.
f. Renewable energy refers to energy derived from renewable sources, but BEES does not specify what sources these include.
g. In addition to reporting energy impacts in megajoules (MJ), we monetize impacts by multiplying model outputs in MJ by the
average cost of electricity in 2006 ($0.0275/MJ), converted to 2007 dollars ($0.0280/MJ). The 2006 cost of energy is taken from the
Federal Register, February 27, 2006, accessed at: http://www.npga.org/14a/pages/index.cfm?pageid=914. The cost was converted
to 2007 dollars using NASA's Gross Domestic Product Deflator Inflation Calculator, accessed at:
http://cost.isc.nasa.gov/inflateGDP.html.
h. In addition to reporting water impacts in gallons, we monetize impacts by converting model outputs from liters to gallons and
multiplying by the average cost per gallon of water between July 2004 and July 2005 ($0.0023/gal), converted to 2007 dollars
($0.0024/gal). The 2005 cost of water is taken from NUS Consulting Group, accessed at:
https://www.energyvortex.com/files/NUS_quick_click.pdf. The cost was converted to 2007 dollars using NASA's Gross Domestic
Product Deflator Inflation Calculator, accessed at: http://cost.isc.nasa.gov/inflateGDP.html.
i. Greenhouse gas emissions have been converted to tons of C02 equivalent using U.S. Climate Technology Cooperation Gateway's
Greenhouse Gas Equivalencies Calculator accessed at: http://www.usctcgatewav.net/tool/. This calculation only includes C02 and
methane.
j. BEES reports waste as "end of life waste." In contrast, SimaPro reports "solid waste." It is not clear if these waste metrics are
directly comparable as SimaPro does not specify whether "solid waste" refers to manufacturing waste, end-of-life waste, or both.
ES-7
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The results show that current beneficial use of fly ash in concrete and FGD gypsum in wallboard results
in positive environmental impacts. The most significant impacts include energy savings and water use
reductions. Energy savings associated with the use of fly ash and FGD gypsum totals approximately 167
billion megajoules of energy (or approximately $4.7 billion in 2007 energy prices). Based on the average
monthly consumption of residential electricity customers, this is enough energy to power over 4 million
homes for an entire year. Avoided water use totals approximately 121 billion liters or approximately
$76.9 million in 2007 water prices).4 This is roughly equivalent to the annual water consumption of
61,000 Americans.5 The extrapolated beneficial impacts also include key impacts such as avoided
greenhouse gas (11.5 million tons of avoided CO2 equivalent), and avoided air emissions (30.3 million
kilograms of avoided NOx, and 23.9 million kilograms of SOx).
This report also presents a distributional screening analysis using the EIO-LCA model that indicates
significant avoided environmental impacts from reductions in the demand for cement or virgin gypsum
that are distributed across several economic sectors. From the perspective of energy and air emissions,
cement manufacturing leads to large impacts, and is in general the largest source of emissions across the
supply chain. Reducing the amount of cement produced by beneficially reusing products can lead to large
supply chain-wide reductions of emissions. Comparatively, the impact of the substitution of FGD
gypsum for virgin gypsum in wallboard manufacturing is less clear, as the model was not able to
adequately represent the wallboard sector.6
The preliminary results of this initial analysis suggest that a more detailed evaluation of the beneficial
impacts of the beneficial use of CCPs could assist EPA in the more specific estimation of the
achievements of the RCC program. A more detailed analysis would require:
The development of realistic and effective beneficial use scenarios that incorporate more detailed
descriptions of markets, beneficial uses, and policies. Realistic scenarios should reflect key
market dynamics and limits such as distance to markets and virgin material prices, and be able to
assess the impacts of these dynamics on the growth potential for specific beneficial uses.
The development of a methodology to attribute beneficial use impacts to specific EPA/RCC
efforts and programs. A phased approach may be employed that initially assumes all impacts
result from EPA actions. This assumption could then be refined to reflect specific strategies,
policies, and other efforts, and link these, where possible, to specific changes in beneficial use
practices and markets.
The expansion of the assessment to include additional CCPs and beneficial use applications. This
analysis only examines the beneficial impacts of substituting using fly ash for finished portland
cement in concrete and substituting FGD gypsum for virgin gypsum in wallboard manufacturing.
The two processes represent less than 50% of the total beneficial use of CCPs. Additional high
volume applications that EPA may wish to analyze include: the use of fly ash as a raw feed in
cement clinker; the use of boiler slag as blasting grit; and the use of various CCPs in structural fill
and waste stabilization. In addition, the Agency may investigate the beneficial impacts of lower
volume applications to identify those that may have potentially high incremental impacts.
4 Based on the assumption that an average residential customer uses 938 kilowatt-hours per month. Department of Energy, Energy Information
Administration, "Energy Basics 101," http://www.eia.doe.gov/basics/energybasics101.html, accessed August 30, 2007.
5 Based on 2000 USGS per capita water use estimate of 1,430 gallons per day. Lumia et al., United States Department of the Interior, United
States Geological Survey, Summary of Water Use in the United States, 2000.
6 EIO-LCA models impacts at the sector level using NAICS codes but an individual NAICS code does not exist for the wallboard manufacturing sector.
ES-8
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CHAPTER 1: INTRODUCTION
The U.S. Environmental Protection Agency's Office of Solid Waste (EPA OSW) is currently considering
the strategic direction of solid and hazardous waste policy. As part of this effort, OSW is developing
methods to evaluate the environmental, human health, and economic outcomes of specific EPA programs
to support strategic planning and program evaluation. Three important areas of focus in this transition
are:
Measurement of materials flow and life cycle impacts related to waste minimization and materials
recovery and reuse, including an emphasis on "upstream" resource conservation beneficial
impacts;
Documentation of the impacts of voluntary programs, including the various efforts and materials
targeted by EPA's Resource Conservation Challenge (RCC);7 and
Development of data and approaches that can support annual performance reporting under the
Government Performance and Results Act (GPRA) and OMB's Performance Assessment Rating
Tool (PART) evaluations.
As an initial step in the development of methods to assess the beneficial impacts of program benefits for
both voluntary programs and PART, OSW is examining the extent to which the costs and benefits of
source reduction, reuse, and recycling may be quantified for a range of materials targeted by the RCC.
This report examines one of the materials targeted under the RCC: coal combustion products (CCPs).
CCPs are produced during coal-burning process at electric utilities and in industrial boilers. Beneficial
use of CCPs refers to the use or substitution of CCPs for other products based on performance criteria.
Under the RCC, EPA has established three goals for increased beneficial use of CCPs:
Achieve a 50 percent beneficial use rate of CCPs by 2011;
Increase the use of coal fly ash in concrete by 50 percent (from 12.4 million tons per year in 2001
to 18.6 million tons by 2011); and
Reduce greenhouse gas emissions from concrete production by approximately 5 million metric
tons CO2 equivalent by 2010.8
Additionally, to support efforts to increase the beneficial use of CCPs, EPA has established partnerships
with several industry groups and government agencies, including the American Coal Ash Association
(ACAA), Utility Solid Waste Group (USWAG), the U.S. Department of Energy (DOE), and the Federal
Highway Administration (FHWA). Efforts within these partnerships include: promoting the beneficial
use of CCPs through the development of web resources; developing technical guidance on the best
practices for the beneficial use of CCPs; holding educational workshops and outreach support for CCP
users; and providing recognition for the innovative beneficial use of CCPs.
7 The RCC is an EPA initiative that seeks to identify and encourage innovative, flexible, and protective ways to conserve natural resources and
energy. Specifically, the RCC is a cross-Office program that assists in developing voluntary programs that promote the source reduction, reuse,
and recycling of materials.
8 U.S. EPA, "About C2P2," accessed at http://www.epa.gov/epaoswer/osw/conserve/c2p2/about/about.htm.
1-1
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OVERVIEW OF REPORT
This report serves two purposes: (1) To provide an initial assessment of the market dynamics that affect
the generation, disposal, recovery, and beneficial use of CCPs; and (2) to provide a preliminary life cycle
analysis of beneficial impacts of CCP use, including an initial estimate of the baseline beneficial use
impacts with current (2005) CCP levels and, for some materials, the beneficial impacts associated with
achieving the 2011 RCC goal. Ultimately, in combination with specific information about explicit RCC
efforts, this report can be used to support the development and implementation of measures of program
efficiency.
Organization of Report
The report proceeds in four chapters following this introduction. To provide market context, the second
chapter characterizes the current generation and management of CCPs. The third chapter summarizes the
current market structure for CCPs and outlines specific EPA efforts to increase their beneficial use. The
fourth chapter uses baseline and Agency goal information, and available LCA tools to provide a
preliminary life cycle analysis of the impacts of beneficial use of FGD gypsum and fly ash. The final
chapter discusses the potential to extrapolate these beneficial use impacts and attribute them to EPA
program efforts.
1-2
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CHAPTER 2: BASELINE CHARACTERIZATION OF CCP
GENERATION AND BENEFICIAL USE
The coal-fired power industry is the largest generator of CCPs. Other industries, such as commercial
boilers and mineral and grain processors that use coal as a fuel source also produce small quantities of
CCPs. Because these other industries generate such small quantities of CCPs relative to the coal-fired
electric power industry, this report focuses solely on the coal-fired electric power industry.9
CCPs are categorized by the process in which they are generated, which varies by plant. CCPs include the
following materials:
Fly ash. Exhaust gases leaving the combustion chamber of a power plant entrain fly ash particles
during the coal combustion process. To prevent fly ash from entering the atmosphere, power
plants use various collection devices to remove it from the gases that are leaving the stack. Fly
ash is the finest of coal ash particles. The American Society for Testing and Material (ASTM)
identifies two classes of fly ash suitable for beneficial use based on chemical composition. Class
F fly ash results from the burning of anthracite or bituminous coal, while Class C fly ash results
from the burning of lignite or subbituminous coal.
Bottom ash. With grain sizes ranging from fine sand to fine gravel, bottom ash is coarser than
fly ash. Utilities collect bottom ash from the floor of coal burning furnaces used in the generation
of steam, the production of electric power, or both. The physical characteristics of the product
generated depend on the characteristics of the furnace.
Flue Gas Desulphurization (FGD) material. FGD material results from the flue gas
desulphurization scrubbing process that transforms gaseous SO2, released during coal
combustion, to sulfur compounds. Coal-fired power plants employ either a wet or dry scrubbing
method to remove SO2 from their emissions. The final by-product of wet scrubbing is primarily
FGD gypsum, although small amounts of other materials (e.g., ash, metals) are also produced.10
In this report, we refer to these other materials as "other FGD wet material." The dry method
produces by-products that consist of mainly calcium sulfite, fly ash, portlandite, and calcite.
Collectively, we refer to these materials as "FGD dry material."11 All three materials, FGD
gypsum, other FGD wet scrubber material, and FGD dry scrubber material, can be used in a
growing number of beneficial use applications.
Boiler Slag. Boiler slag consists of molten ash collected at the base of cyclone boilers. Facilities
cool boiler slag with water, which then shatters into black, angular pieces that have a smooth
appearance.
Fluidized Bed Combustion (FBC) ash (not pictured in Exhibit 2-1). A fluidized bed
combustion boiler, a type of coal boiler that combines the coal combustion and flue gas
9 As of the writing of this report, we were unable to locate data estimating the quantities of CCPs attributable only to the electric power industry;
however, since the coal power industry consumes approximately 92 percent of all U.S. coal, it is reasonable to assume that significant majority of
CCPs result from the burning of coal at coal-fired power plants. Department of Energy, Energy Information Administration, "U.S. Coal
Consumption by End-Use Sector," http://www.eia.doe.gov/cneaf/coal/quarterlv/html/t28p01p1.html. June 2007.
10 FGD gypsum has the same chemical structure as naturally occurring gypsum (calcium sulfate dehydrate).
11 Electric Power Research Institute. 1999. Environmental Focus: Flue Gas Desulfurization By-Products. BR-114239
2-1
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desulphurization processes within a single furnace, generates FBC ash. FBC ash is rich in lime
and sulfur.
Cenospheres. Generated as a component of fly ash in high temperature coal combustion,
cenospheres consist of extremely small, lightweight, inert, hollow spheres comprised largely of
silica and alumina that are filled with low-pressure gases.12 When fly ash is disposed in
settlement lagoons, cenospheres can be collected on the surface where they can be skimmed for
use in manufacturing processes.
At a typical coal-fired power plant, coal combustion generates CCPs during several phases of the process.
Exhibit 2-1 illustrates the collection of several types of CCPs. As depicted below, facilities remove
bottom ash and boiler slag from the base of the furnace. Fly ash accumulates in the particulate collection
device, while FGD material collects in the SO2 control device.
EXHIBIT 2-1: COAL COMBUSTION PROCESS AT A COAL-FIRED POWER PLANT
Convective
Stack
Furnace
Coal
Handling
Coal
Bunker
FLY ASH & CENOSPHERES
Pass
/ Air
Burners
<
FGD MATERIAL
Pre heater 1 \ so,
Particulate \Gontrot
Collection \ Device
DeviCG
HT
\
BOTTOM ASH/ BOILER SLAG REMOVAL
Source: Energy Information Administration, accessed at: www.eia.doe.gov.
CURRENT QUANTITIES OF CCPS GENERATED AND MANAGED
In 2005, the coal-fueled electric power industry generated approximately 123 million short tons of CCPs.
Of these, the industry disposed of approximately 74 million short tons to landfills, while beneficially
using approximately 50 million short tons in products. Exhibit 2-2, below, presents the current quantities
of CCPs generated and managed, in the context of other materials targeted by the RCC. Except for
construction and demolition material, the U.S. generates larger quantities of CCPs than other industrial
and municipal solid waste (MSW).
Cenospheres range in size from 20 to 5000 microns.
2-2
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EXHIBIT 2-2: RCC MATERIALS BY QUANTITIY
MATERIAL3
caD Material1
CCPs2
Paper and Paperboard3
Packaging3
Organics3
Foundry Sand4' d
Chemicals5
QUANTITY
GENERATED
(MILLION SHORT
TONS)
331
123
83
74
56
9.2
0.04
QUANTITY
RECOVERED/
BENEFICIALLY USEDb
(MILLION SHORT
TONS)
21 4C
50
40
29
17
2.6
NA
QUANTITY
DISPOSED
(MILLION SHORT
TONS)
118
74
43
45
39
6.6
NA
YEAR
2003
2005
2003
2003
2003
2005
2003
Notes:
a. Under the RCC 2005 Action Plan, increases in the rate of AASW recovery and reduction of priority and toxic chemicals are also
targeted. We have included these material streams in this exhibit even though they are not targeted specifically for
beneficial use.
b. The figures shown for paper and paperboard, packaging, and organics are the quantities recovered from the AASW stream.
The figures shown for C&D debris, CCPs, and foundry sand are quantities that are beneficially used.
c. A Construction Materials Recycling Association member survey estimates that approximately 270 million tons of C&D material
including asphalt and concrete from roads, bridge-related infrastructure, and land clearing debris was recovered in 2004.
d. The foundry sand quantity generated is uncertain, but estimates fall within the range of 6 to 10 million tons/year. Due to
the lack of precise data on annual quantities generated and managed, the quantity disposed may include foundry sand that is
being beneficially used as daily landfill cover.
Sources:
1. US EPA, "Characterization of Building-Related Construction and Demolition Debris in the United States" and
"Characterization of Road-related Construction and Demolition Debris in the United States," 2005. (Note that these
documents are preliminary and are currently undergoing peer-review).
2. American Coal Ash Association (ACM), "2005 Coal Combustion Product (CCP) Production and Use Survey," accessed on
October 29, 2006 at: http://www.acaa-usa.org/PDF/2005_CCP_Production_and_Use_Figures_Released_by_ACAA.pdf.
3. US EPA, "Municipal Solid Waste in the United States: 2003 Data Tables," Table 1, accessed on October 26, 2006 at:
.
4. American Foundry Society (AFS). "Foundry Industry Benchmarking Survey," August 2007.
5. US EPA, "Draft National Priority Trends Report (1999-2003) Fall 2005," as reported in the NPEP GPRA2008 database of TRI
data from 1998-2003.
The American Coal Ash Association (ACAA), a trade association whose purpose is to advance the
beneficial use of CCPs, conducts an annual survey of coal-fired electric plants to collect data on the
production, disposal, and use of CCPs in the U.S.13 Exhibit 2-3 summarizes the 2005 survey on
generation, disposal, and beneficial use of various CCP categories.
13 The ACAA survey is administered to both ACAA members and non-members. ACAA members account for approximately 40 percent of private
power generation. Not all survey recipients complete the survey each year. ACM extrapolates survey respondent data to the entire coal-fired
electricity generation industry. To the extent that other coal-burning industries are not represented in the ACM sample, the survey may
underestimate the quantity of CCPs generated and/or beneficially used.
2-3
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EXHIBIT 2-3: SUMMARY OF CCP GENERATION AND MANAGEMENT IN 2005
PRODUCT
Fly Ash
Flue Gas Desulfurization (FGD) Material
Other FGD Wet Material
FGD Gypsum
FGD Dry Material
Bottom Ash
Boiler Slag
Fluidized Bed Combustion (FBC) Ash
Cenospheresb
Total CCPs
Notes:
CCPS GENERATED
(MILLION SHORT
TONS)
71.10
31.10
17.70
11.98
1.43
17.60
1.96
1.37
Not available
123.13
BENEFICIALLY
USED
(MILLION SHORT
TONS)
29.12
10.12
0.69
9.30
0.16
7.52
1.90
0.94
0.08 c
49.61
PERCENT
USED
41%
33%
4%
77%
11%
43%
97%
69%
Not available
40%
(see note 2)
QUANTITY
DISPOSED
(MILLION
SHORT TONS)a
41.98
20.99
17.01
2.71
1.27
10.06
0.07
0.42
Not available
73.51
PERCENT
DISPOSED
59%
67%
96%
23%
89%
57%
3%
31%
Not
available
60%
a. Calculated by subtracting quantity beneficially used from quantity generated.
b. The ACAA's "CCP Production and Use Survey" does not report total generation or disposal quantities for cenospheres, only sales.
c. Follow-up communication with D. Goss on 11-10-07 indicated that this figure may be misreported in the 2005 CCP Survey. The
actual figure is likely to be an order of magnitude less, or approximately 0.008 million short tons.
Note 2: Results from the 2006 CCP Productio
up from 40.29 percent reported for 2005. Thi
2006 results were received too late for incor|
Source:
n and Use Survey conducted by the ACM indicate a total utilization rate of 43.43 percent,
s reflects an ongoing upward trend in the CCP utilization rate over the past decade. The
joration into the benefits analysis.
American Coal Ash Association. "2005 Coal Combustion Product (CCP) Production and Use Survey," accessed at: http://www.acaa-
usa.org/PDF/2005_CCP_Production_and_Use_Figures_Released_by_ACAA.pdf.
Exhibit 2-3 illustrates several important aspects of the generation, beneficial use, and disposal of CPPs:
Of reported materials, fly ash constitutes the largest proportion (58 percent) of CCP materials
generated in 2005. FGD material follows at 26 percent.14 Bottom ash, boiler slag and FBC ash
collectively comprise the remaining 17 percent of CCPs generated in 2005.
Boiler slag and FGD gypsum have the highest percentage of beneficial use of the six coal
combustion products.
Fly ash, FGD material (other than FGD gypsum), and bottom ash have the highest disposal rates.
In addition to quantities of fly ash reported in the ACAA survey, stockpiles may provide another potential
source of fly ash for certain beneficial uses. Industry sources estimate that between 100 million and 500
The quantity of cenospheres generated is not reported by ACAA so the 58 percent estimate could be higher if cenospheres were included.
2-4
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million tons of fly ash have accumulated in U.S. landfills since the 1920s, when disposal of fly ash in
landfills began.15'16
Beneficial Use Options
The chemical and physical properties of CCPs allow for their use in a wide range of products. CCPs may
be used as a component of various building materials (i.e., as a replacement for portland cement in
concrete) or as a direct replacement for other virgin materials such as sand, gravel, or gypsum. The
physical properties of CCPs make them especially useful for construction and industrial materials. Size,
shape, and chemical composition determine the suitability of specific material flows for beneficial use.
Higher value applications, such as use in cement or concrete products, require comparatively stringent
specifications (in terms of size, shape and chemical composition), whereas lower value uses, such as
structural or mining fills, can accept more variable materials. For this reason, EPA has found that lower
technology applications that require large volumes of CCPs may present the greatest potential for
expanded beneficial use.17
Exhibit 2-4 summarizes the most common beneficial uses for each CCP. As shown, this table excludes
cenospheres and FBC ash as data on the primary beneficial uses of these materials are not available.
EXHIBIT 2-4: COMMON BENEFICIAL USES FOR CCPS
CCP
BENEFICIAL USE
Fly Ash
Concrete: Concrete consists of a mixture of approximately 25% fine aggregate (sand), 45%
gravel, 15% portland cement, and 15% water. Class C and class F fly ash can replace a percentage
of the portland cement component of concrete. Fly ash contributes to enhanced concrete
strength and durability, and is typically less expensive than portland cement.
Cement clinker: Clinker is an intermediary product of the portland cement manufacturing
process. Clinker is formed when a raw mix consisting of limestone, clay, bauxite, iron ore and
quartz are heated in a kilm at higher temperatures. Fly ash can be blended with limestone or
shale and fed into the cement kiln to make clinker, which is then ground into portland cement.
Structural fill: Structural fill is an engineered material used to raise or change the surface
contour of an area and to provide ground support beneath building foundations. It can also be
used to form embankments. Depending on the soil type, fly ash can replace a percentage
(generally 50 percent) of virgin rock, dirt, sand or gravel in structural fill.
Waste stabilization: Fly ash can be used in place of portland cement, cement kiln dust, or lime
to solidify and harden wet or liquid waste before it is landfilled. Class C fly ash hardens by itself
in contact with moisture, but class F fly ash must be mixed with another hardening agent, such
as portland cement, in order to be used in waste stabilization.
15 Personal communications with Dave Goss, ACAA and Tom Janson, WE Energies, November 27, 2006.
16 The quantity of stockpiled fly ash that is available for beneficial use is unclear. The chemical composition of fly ash varies depending on the type
of coal used, and only two types of fly ash--class C fly ash and class F fly ashmeet the ASTM technical requirements for concrete. It is unclear
how much of the estimated 100-500 million tons of stockpiled fly ash falls into one of these classes. In addition, exposure to moisture or
contamination in the stockpiles can limit the beneficial use options of Class C ash, though, this is not a concern with Class F ash. Information on
these standards can be found at http://www.astm.org.
17 EPA. 1999. "Report to Congress: Wastes from the Combustion of Fossil Fuels." Vol. II. EPA-530-R-99-010, March 1999.
2-5
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CCP
BENEFICIAL USE
FGD Gypsum
Bottom Ash
Boiler Slag
Wallboard: Gypsum wallboard (or drywall) is used as an interior finish in the construction of
homes and building. Wallboard is comprised of a layer of gypsum stucco sandwiched between
two sheets of heavy paper. FGD gypsum can replace 100 percent of virgin gypsum in wallboard
after the excess moisture has been removed.
Agricultural soil amendment: FGD gypsum can be used to replace liming agents as an
agricultural soil amendment for specific soil and crop types.
Cement additive: In the production of portland cement, clinker is blended with a small amount
of gypsum prior to grinding into finished portland cement. FGD gypsum can be used to offset
virgin gypsum in cement manufacture.
Structural fill: Structural fill is an engineered material used to raise or change the surface
contour of an area and to provide ground support beneath building foundations. It can also be
used to form embankments. Bottom ash can be used to offset virgin sand and gravel in structural
fill.
Road base: A road base is a foundation layer underlying a pavement and overlaying a subgrade of
natural soil or embankment fill material. It protects the underlying soil from the detrimental
effects of weather conditions and from the stresses and strains induced by traffic loads. Bottom
ash can be used to offset virgin sand or gravel in road base.
Concrete: Bottom ash can be used as a coarse aggregate for concrete blocks, with its porous
nature often qualifying the product for lightweight classification.
Blasting Grit: Blasting grit is an industrial abrasive used to shape, cut, sharpen, or finish a
variety of other surfaces and materials. Boiler slag can be used as a replacement for other slags
or virgin sand as blasting grit.
Structural fill: Structural fill is an engineered material used to raise or change the surface
contour of an area and to provide ground support beneath building foundations. It can also be
used to form embankments. Boiler slag is occasionally used to offset virgin sand and gravel in
structural fill.
Exhibit 2-5, below, illustrates the quantities of CCPs being used in the most common beneficial use
applications. The applications highlighted in the exhibit represent approximately 80% of the current use
of CCPs.18 We include an expanded version of this table, which details a more inclusive set of CCP
beneficial use applications, in Appendix A.
Relatively minor applications comprise the remaining 20 percent of CCP beneficial uses. These applications include use such as soil stabilizers,
mineral filler in asphalt, and mine reclamation.
2-6
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EXHIBIT 2-5: KEY BENEFICIAL USES FOR CCPS IN 2005 (MILLION SHORT TONS)
APPLICATION
(INDUSTRY)
Concrete8
(Construction)
Structural fillb
(Construction)
Wallboarcf
(Construction)
Raw feed for
cement clinkerd
(Construction)
Waste stabilization6
(Waste Mgmt)
Blasting
Grit/Roofing
Granules
Total - Key Uses
Total - Other
Uses'
TOTAL - ALL USES
COAL FLY
ASH
14.99
5.71
0
2.83
2.66
0
26.19
2.93
29.12
BOTTOM
ASH
1.02
2.32
0
0.94
0.04
0.89
4.41
3.13
7.54
FGD
GYPSUM
0.33
0
8.18
0.40
0
0
8.90
0.36
9.27
OTHER
FGD WET
MATERIAL
0
0
0
< 0.01
0
0
< o.or
0.69
0.69
FGD DRY
MATERIAL
0.01
< 0.01
0
0
0
0
0.02
0.074
0.16
BOILER
SLAG
0
0.18
0
0.04
0
1.54
1.76
0.13
1.89
FBC ASH
0
0.14
0
0
0.14
0
0.28
0.66
0.94
TOTAL
16.35
8.35
8.18
4.22
2.84
1.63
41.57
8.04
49.61
2005 QUANTITY
GENERATED
CCP UTILIZATION
RATEh
71.10
41%
17.60
43%
12.00
77%
17.70
4%
1.43
11%
1.96
97%
1.37
69%
123.13g
40%
(see note 2)
Notes:
a. CCPs are frequently used as a replacement for a portion of portland cement in the manufacture of concrete.
b. Structural fill is an engineered material that is used to raise or change the surface contour of an area and to provide
ground support beneath highway roadbeds, pavements and building foundations. It can also be used to form
embankments.
c. FGD gypsum is used as a substitute for virgin gypsum in wallboard manufacturing.
d. CCPs can be blended with limestone or shale and fed into the cement kiln to make clinker, which is then ground into
Portland cement.
e. The chemical properties of CCPs make them effective stabilizers of biosolids (i.e., sludge from municipal waste water
treatment).
f. Includes quantities beneficially used in minor applications not included in this exhibit, but listed in Appendix A.
g. Includes 115,596 tons of "Other FGD Material" not listed in this table because of the small quantities generated.
h. CCP utilization rates reflect all use applications, some of which are omitted from this table but are included in Appendix
A. Utilization rates are calculated by dividing the total quantity used by the total quantity generated.
Note 2: Results from the 2006 CCP Production and Use Survey conducted by the ACAA indicate a total utilization rate of
43.43 percent, up from 40.29 percent reported for 2005. This reflects an ongoing upward trend in the CCP utilization rate
over the past decade. The 2006 results were received too late for incorporation into the benefits analysis.
Sources:
1. American Coal Ash Association. "2005 Coal Combustion Product (CCP) Production and Use Survey," accessed at:
http://www.acaa-usa.org/PDF/20045_CCP_Production_and_Use_Figures_Released_by _ACAA.pdf.
2. Western Region Ash Group, "Applications and Competing Materials, Coal Combustion Byproducts," accessed at:
http://www.wrashg.org/compmat.htm.
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Exhibit 2-5 illustrates several important aspects regarding the beneficial use options for CCPs:
Concrete, wallboard, structural fill, cement, and waste stabilization comprise the highest volume
beneficial uses of CCPs.
The use of fly ash as a pozzolanic binder in concrete represents the largest single beneficial use
application of a CCP material.19 Fly ash can substitute for finished portland cement in concrete
and can be a valuable additive to concrete mixtures that enhances the strength, durability, and
workability of the concrete product.20
FGD gypsum serves as a substitute for virgin gypsum in wallboard construction. This high value
use represents the second largest use of CCPs, by volume, and second highest utilization rate at
77 percent.
Although one of the smaller material streams, facilities beneficially use boiler slag in blasting
grit, structural fill and waste stabilization, at the highest percentage of all CCPs. Boiler slag
possesses two key properties that make it ideal for beneficial use: (1) the highly uniform quality
of boiler slag increases its acceptance among potential end-users; and (2) boiler slag's unique
abrasive properties make and excellent material for blasting grit and asphalt shingles.21
In comparison to the same ACAA survey conducted in 2004, total CCP utilization from 2004 to 2005 has
increased slightly (0.21 percent). However, it is important to note that both the generation and beneficial
use of CCPs increased during this time period. Both bottom ash and wet FGD material saw modest
decreases in beneficial use rates (4% and 3%, respectively). The greatest increase in utilization rates over
this time period was in boiler slag, with an increase of seven percent.22> 23
19 Fly ash is technically a pozzolanic, not a cementitious material. A cementitious material, such as portland cement, is one that hardens when
mixed with water. A pozzolanic material will also harden with water but only after activation with an alkaline substance such as lime. The
combination of portland cement and water in concrete mixtures creates two products: a durable binder that "glues" concrete aggregates together
and free lime. Fly ash reacts with this free lime to create more of the desirable binder.
20 Personal communication with Tom Pyle, Caltrans, November 2006.
21 EPA. "Boiler Slag," accessed at: http://www.epa.gov/epaoswer/osw/conserve/c2p2/about/about.htm.
22 American Coal Ash Association. "2005 Coal Combustion Product (CCP) Production and Use Survey," accessed at: http://www.acaa-
usa.org/PDF/20045_CCP_Production_and_Use_Figures_Released_by_ACAA.pdf. and "2004 Coal Combustion Product (CCP) Production and Use
Survey," accessed at: http://www.acaa-usa.org/PDF/2004_CCP_Survey(9-9-05).pdf.
23 More efficient furnace types that use pulverized coal are replacing the cyclone and slag-tap furnaces that typically produce boiler slag. The
replacement of these boiler types is decreasing the available supply of boiler slag. EPA. "Boiler Slag," accessed at:
http://www.epa.gov/epaoswer/osw/conserve/c2p2/about/about.htm.
2-8
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CHAPTER 3: MARKET STRUCTURE OF BENEFICIAL USE FOR
CCPs
Understanding the factors that affect beneficial use of CCPs requires consideration of the underlying
markets affecting its generation and management. The CCP market includes three market segments: (1)
coal-fired utilities, (2) intermediaries: CCP marketers and consultants, and (3) end-users. In addition,
state regulators determine the extent to which CCPs can be beneficially used by defining the regulatory
context in which these actors operate. This chapter considers the factors affecting beneficial use decisions
among these groups participating in the marketplace. We then present a discussion of opportunities for
growth in the general CCP markets, along with a more specific illustration using three common beneficial
applications. Finally, we discuss our efforts to improve market conditions for CCPs.
Three main challenges exist in developing the beneficial use market for CCPs. First, because CCPs are a
heavy material to transport, the distance between the location of the coal-fired utility generating the CCPs
and the potential end-user is a driving factor in determining whether the CCPs will be beneficially used in
a project. Another difficulty in developing the beneficial use market is the capacity for individual coal-
fired utilities to provide a quantity of high quality CCPs sufficient to meet the end-users' demands. The
ability of end-users to obtain enough CCPs for their purposes is an important consideration in driving
demand for CCPs. Finally, as noted above, the variability in use options across states poses a challenge to
both coal-burning plants and end-users in trying to determine applicable beneficial use options for CCPs.
COAL-FIRED UTILITY PRACTICES: CCP SUPPLY
The coal-fired power industry is the largest generator of CCPs in the United States. As noted previously,
other industries that use coal as a fuel source in commercial or industrial boilers (e.g., mineral and grain
processors) also produce small quantities of CCPs. Coal-generated electricity supplies approximately
50% of the electricity consumed in the United States.24 Since electricity demand is projected to increase
by 40% by 2020 and coal will continue to be an important fuel source, it is likely that the quantity of
CCPs produced and available for beneficial use will also increase.25'26
Approximately 400 to 500 coal-fired electric utilities currently operate in the U.S.27 Exhibit 3-1 shows the
geographic distribution of coal consumption by electric power plants across the U.S. Coal consumption
by power plants is greatest in the East North Central region of the U.S., but consumption remains
relatively high throughout the entire Central and Southern United States. Coal consumption is low in the
contiguous and noncontiguous Pacific regions of the U.S. and in New England. CCP generation closely
approximates the geographic distribution of coal consumption across the U.S., but CCP generation is not
directly proportional to coal consumption. The composition of coal varies regionally in the U.S. For
example, the non-combustible portion (commonly referred to as "ash") of Western bituminous coal is
higher than that of Western sub-bituminous coal (approximately 10% to 15% and 4% to 6% ash,
respectively). Coal with a higher non-combustible ash content will yield greater quantities of CCPs when
combusted.
24 American Coal Foundation, "All About Coal: Fast Facts About Coal," accessed at: http://www.teachcoal.org/aboutcoal/articles/fastfacts.html.
25 Center for Energy and Economic Development, "Growing Demand," accessed at: http://www.ceednet.org/ceed/index.cfm?cid=7500,7582.
26 American Coal Foundation, "Coal's Past Present and Future," accessed at: http://www/teachcoal.org/aboutcoal/asrticles/coalppf.html.
27 Personal communication with Dave Goss, American Coal Ash Association, April 2006.
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EXHIBIT 3-1: ELECTRIC POWER SECTOR CONSUMPTION OF COAL IN 2004, BY CENSUS REGION
(MILLION SHORT TONS AND PERCENT CHANGE FROM 2003)
U.S. Total = 1.015.1 (1.0%)
Pacific
Contiguous
9.9 (-7.8%)
New England
8.3(1.!
Source: Energy Information Administration, accessed at: www.eia.doe.gov.
Several factors influence a utility's decision to supply CCPs for beneficial use. Economic factors are the
primary consideration and include:
Landfill disposal costs. For many utilities, the sale of CCPs for beneficial use is a means of
reducing operating costs through avoidance of landfill tipping fees. In order for beneficial use of
CCPs to be competitive, the cost of reselling CCPs, minus revenue from the sale, must be less
than the cost of landfill disposal. Landfill tipping fees vary regionally but range from $5 per ton
to $45 per ton.28 Avoiding landfill disposal costs may be a significant incentive for a utility to
engage in beneficial use.
Revenue from sale. Depending on the type of CCP, an electric utility may or may not receive
revenue for its ash. For some CCP types, marketers will accept ash as a service to the plant
(allowing the plant to avoid disposal costs) but do not pay for the ash. For other CCP types,
especially fly ash, boiler slag and cenospheres, the revenue received can be a significant incentive
for a utility to market its ash.29
Transport costs. CCPs are heavy materials, which makes transport over long distances
expensive. Transport distance between the utility and the nearest landfill or end-user is a
significant determinant in the management of CCPs.
Processing costs. Approximately 90% to 95% of CCPs do not require processing prior to
beneficial use. However, higher value applications that require specialized CCP products may
require processing to meet material specifications.
28 Personal communication with Dave Goss, American Coal Ash Association, April 2006.
29 Personal communication with Dave Goss, American Coal Ash Association, May 2006.
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Storage costs. In many parts of the country, the production of coal ash is high during both the
coldest and hottest months of the year when people are heating and cooling their homes, offices
and schools. However, the winter season is often the slowest period for construction and other
applications that beneficially use the fly ash. As a result, it is necessary to store CCPs until they
can be utilized. Typically, domes are inflated adjacent to boilers for the CCP collection. The cost
of storing fly ash or other CCPs during the winter months may be a deterrent to beneficial use by
a utility.
Marketing costs. In order to attract buyers of CCPs, a marketer must devote financial resources
to marketing their CCP product(s) for beneficial use. Some utilities market their CCPs directly to
end-users, but others pay a third party marketer or broker to negotiate CCP sales.
In the end, a generator's decision to make CCPs available for beneficial use rather than disposal is a result
of a confluence of all the above factors, as well as non-economic factors such as access to information
about permissible applications and availability of technical assistance. Depending on the circumstances, a
coal-fired utility may weigh certain factors more heavily than others. For example, since off-site disposal
and transport to a marketer or end-user both require hauling, total transport distance to the off-site facility
is an important consideration. If the off-site disposal facility is closer, then a generator may opt to send
its CCPs to the landfill instead of to the marketer or end-user. However, if the avoided disposal costs
from the marketing arrangement are higher than the cost of offsite disposal, then avoided costs may be
enough to offset the additional cost to transport the materials to the marketer or end-user. In addition, a
coal-fired utility may be more willing to absorb higher costs (of transport, marketing, etc.) for higher-
value materials and uses for which it can charge a higher premium (e.g. fly ash as a portland cement
substitute in concrete).30
INTERMEDIARIES
Many coal-fired electric generators market their CCPs through a third-party marketer instead of selling
directly to the end-user. In these cases, a utility perceives an efficiency in outsourcing the marketing of its
CCPs. Marketers typically accept all of a generator's CCPs as a service to the company, sell the
marketable portion, and dispose of the portion that is not salable. The marketer typically bears the cost of
hauling CCPs from the utility and incorporates this cost into the sale price.
END-USERS AND PURCHASERS: CCP DEMAND
Several factors influence an end-user's decision to use CCPs in their product. Such considerations
include:
Price of CCPs relative to the price of virgin materials.31 If the price of a virgin material is less
than the price of CCPs (which will reflect cost factors such as transport distance, processing and
storage costs), end-users will generally purchase virgin materials. In areas where virgin materials
are abundant and inexpensive, CCPs may not be economically viable. Exhibit 3-2 shows the
typical price ranges for CCPs used in various applications relative to the virgin materials they
replaces.
30 Note that the transfer of CCPs from generators to users may lead to potential cost savings for the generators. It may be possible for generators
to shift liability (and related costs) associated with CCPs to users of the product. The law on this matter is not well-defined and needs to be
clarified to determine the magnitude of any potential cost savings.
31 Note that the "price" of CCPs represents how much an end-user would pay for the product.
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EXHIBIT 3-2: SAMPLE CCP AND VIRGIN MATERIAL PRICES FOR CCP APPLICATIONS
VIRGIN MATERIAL
Portland cement
Virgin aggregate for fill
Virgin aggregate for road base
Lime for soil stabilization
(Hydra ted lime)
Lime for waste stabilization
(Quicklime)
Virgin aggregate for snow and ice
control
Gypsum for wallboard interior
2005 AVG PRICE,
(PER TON, FREE ON
BOARD)"'"
$80
$3
$5
$83
$66
$5
$4.50- $12.0
CCP SUBSTITUTE
Concrete quality fly ash
Boiler slag
Fly ash for flowable fill
Bottom ash or fly ash
for road base
Fly ash for soil
stabilization
Fly ash for waste
stabilization
Bottom ash for snow
and ice control
FGD Gypsum
2005 AVG PRICE,
(PER TON, FREE ON
BOARD)3
$0 to $45
Not available
$1
$4 to $8
$10 to $20
$15 to $25
$3 to $6
$0 - $8.00
Notes:
a. Virgin material prices are reported by USGS while CCP prices are provided by ACAA. This price data represents the
best available information, and should be cross-compared with caution, as the data may not capture all factors
driving price variability.
b. "Free on Board" is a shipping term, which indicates that the supplier pays the shipping costs (and usually the
insurance costs) from the point of manufacture to a specified destination, at which point the buyer takes
responsibility.
Sources:
1. USGS, "Mineral Commodities Summary 2006: Cement," accessed at:
http://minerals.usgs.gov/minerals/pubs/commodity/cement/cemenmcs06.pdf
2. USGS, "Mineral Commodities Summary 2004: Construction Sand and Gravel," accessed at:
http:/ /minerals. usgs.gov/minerals/pubs/commodity/sand_£t_gravel_construction/sandgmyb04.pdf
3. USGS, "Mineral Commodities Summary 2005: Lime," accessed at:
http:/ /minerals, usgs.gov/minerals/pubs/commodity /Iime/lime_myb05.pdf
4. USGS, "Mineral Commodities Summary 2006: Gypsum," accessed at:
http://minerals.usgs.gov/minerals/pubs/commodity/gypsum/gypsumcs06.pdf
5. American Coal Ash Association, "Frequently Asked Questions," accessed at: www.acaa-usa.org
6. Miller, Cheri . Gypsum Parameters. Presentation at WOCA Short Course: "Strategies for Development of FGD Gypsum
Resources."
Technical fit between CCPs and use application. CCPs have varying physical and chemical
characteristics due to differences in coal types, combustion processes, air pollution control
technologies, and CCP management practices at individual power plants. To be beneficially used
in a particular application, the chemical and physical properties of the CCP must align with the
engineering requirements of that application. For example, high carbon content or the presence
of air emission additives may render some CCPs unsuitable for some use applications.
Sufficient quantities of CCPs. Some beneficial use applications require larger volumes of CCPs
than are typically produced at a single power plant. Where demand for CCPs is greater than the
supply generated by a single plant, the end-user may need to purchase CCPs from multiple
suppliers; this can increase transaction costs.
State Regulations. Regulations governing beneficial use of CCPs vary by state. In many states,
beneficial use of CCPs must be approved on a project-by-project basis. Currently, public and
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environmental health considerations drive state regulatory decisions concerning beneficial use of
CCPs in end-use applications.32'33
Incomplete science. In absence of definitive data on health risks associated with the beneficial
use of CCPs, some states have chosen to limit the use of CCPs in building materials. For
example, EPA research has found that CCPs may release small quantities of mercury to the
ambient air during use in certain industrial processes.34 Noting this research, States have
questioned the safety of using fly ash in cement to be used in schools.35
MARKET DYNAMICS OF SPECIFIC USE APPLICATIONS
The beneficial use markets for CCPs depend on the physical properties of the materials, the demand for
their particular uses, and the supply of materials available for use. Exhibit 3-3, below, summarizes the
current state of the beneficial use markets for the suite of CCPs, along with an analysis of the potential for
growth in the beneficial use market for each material. An established market contains four key elements,
all of which are interconnected:
Generators producing a consistent supply of materials;
End-users with the demand to use the product;
Well-known, accepted beneficial use applications; and
A distribution system to transport materials from generators to users.
Limited markets may have a subset of these key elements, but likely need a shift in technology, demand,
or price to increase beneficial use of the product. Emerging markets are typically unorganized and the
connections between the elements are not fully formed.
Energy 6t Environmental Research Center, University of North Dakota, "Review of Florida Regulations, Standards, and Practices Related to the
Use of Coal Combustion Products: Final Report," April 2006, accessed at: http://www.undeerc.org/carrc/Assets/TB-FLStateReviewFinal.pdf.
33 Some states, such as Wisconsin, have set up regulatory schemes designed to speed up the approval process for products using beneficial use
materials such as CCPs. Currently, Wisconsin requires initial leachate testing of the material to be beneficially used, which leads to a specific
rating. Materials that fall into a standard rating class are automatically approved for specific uses. For example, material found to meet drinking
water standards can be used in any application, whereas material found to have a moderate level of contamination, may only be approved for
encapsulated uses. Users are also required to submit annual reports demonstrating testing of CCPs. Personal communication with Bizhan
Sheikholeslami, Wisconsin Department of Natural Resources, November 2006.
34 Hassett, David J., Debra F. Pflughoeft-Hassett, Dennis L. Laudal, and John H. Pavlish. 1999. Mercury Release from Coal Combustion Byproducts to
the Environment.
35 Personal Communication with Antoinette Stein, State of California Department of Health Services, June 2006.
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EXHIBIT 3-3: CCP BENEFICIAL USE MARKETS
CCP
STATE OF BENEFICIAL USE
MARKET
POTENTIAL FOR MARKET GROWTH
Fly Ash
Established markets
The markets for fly ash have the potential to continue
to grow. Generators produce fly ash in large quantities
and there are several well-known, high-value uses.
Currently, only 41% of fly ash is beneficially used.
FGD Gypsum
Established markets
The FGD gypsum market has room for moderate growth.
FDG gypsum wallboard is an accepted alternative to
virgin gypsum wallbaord with users often directly
connected to generators. Currently, 77% of FDG gypsum
is beneficially used. Other uses are emerging but are
currently limited, and data on market opportunities are
limited.
Dry FGD Material
Limited market
The current market for dry FDG material appears to
have only limited potential for growth. Uses for the
material appear to be limited to relatively low-value
uses, such mine reclamation. Currently, only four
percent of this material is beneficially used. Data on the
market opportunities for this material are limited.
Other Wet FGD Material
Limited market
The current market for other FDG wet material appears
to have only limited potential for growth. Uses for the
material appear to be limited to relatively low-value
uses, such mine reclamation. Currently, only 11% of this
material is beneficially used. Data on the market
opportunities for this material are limited.
Bottom Ash
Established markets
The markets for bottom ash have the potential to
continue to grow. Generators produce bottom ash in
large quantities and there are several well-known, high-
value uses. Currently, only 43% of bottom ash is
beneficially used.
Boiler Slag
Established markets
The markets for boiler slag are mature and have limited
opportunity for growth. Since approximately 97% of
boiler slag is beneficially used (primarily as blasting
grit), supply is currently roughly equivalent to demand.
FBC Ash
Established markets
The markets for FBC ash have potential for moderate
growth, although mainly for low-value uses. Currently
nearly 70% of FBC ash is beneficially used.
Cenospheres
Emerging market
The markets for cenospheres have the potential for
growth as information on their uses becomes more
widely available. However, information regarding
potential uses is limited at this time. Currently the
beneficial use rate for cenospheres is unknown.
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Aside from the boiler slag market, the markets for the various CCPs generally have room for growth.
EPA programs that aim to increase growth in the markets for CCPs by targeting beneficial use
applications that are well-accepted practices in the industry may have significant success in helping
expand these markets by overcoming targeted technical, administrative and technical and informational
hurdles. The economic viability of the top three beneficial uses (by volume) is considered individually
below. Concrete, gypsum wallboard, and structural fill are all long-standing, widely accepted uses for
CCPs.
Concrete
Certain performance benefits can be attained through the use of coal fly ash in concrete, including greater
workability, higher strength, and increased longevity in the finished concrete product.36 Fly ash
substitutes directly for portland cement in the concrete mixing process. This beneficial use represents one
of the highest value applications for CCPs, and has the potential to increase as a result of the current high
demand for portland cement in the U.S.37'38
Industry representatives and some state agencies have stated that there are possible emerging issues
related to regulatory programs for the control of nitrogen oxides (NOx) and mercury in power plant flue
gases. These issues relate to the potential for negative impacts on coal fly ash quality and available
quantities due to the potential for increased mercury contamination in the ash, or unacceptably high levels
of carbon content. There are technology choices that would minimize these impacts on the beneficial use
of coal fly ash. However, the selection of equipment for control of nitrogen oxides and mercury, and
corresponding technologies potentially necessary to minimize quality impacts on coal fly ash is very
complex, resulting in industry solutions that would be unit-specific. Losses of anywhere between $40/ton
and $80/ton of coal fly ash39 are possible if industry is unable to sell high carbon fly ash as a
supplementary cementitious material in the manufacture of concrete. This estimate also includes the
additional costs associated with the need to dispose of a formerly marketable material.
State of Florida officials noted that installation of air emission controls at coal-fired power plants might
result in increased mercury associated with coal fly ash. Since coal fly ash is used in portland cement
manufacturing, electric utilities and portland cement manufacturers have expressed concern that the
Florida Department of Environmental Protection's (FDEP) New Source Review (NSR) might limit or
even eliminate the use of CCPs for this purpose. Officials also noted that similar impacts might occur for
coal fly ash containing higher levels of unburned carbon or other components resulting from changes in
operations, fuel, or emission controls.40 This may have the potential of jeopardizing the recycling of
many tons of CCPs that are currently reused.
Personal communication with Tom Pyle, Caltrans, November 2006.
37 Strong demand for cement in the U.S. is a result of both increased domestic construction activity and strong demand by growing foreign
economies (especially China).
38 Portland Cement Association. "FAQ: Cement Supply Shortage," accessed at: http://www.cement.org/pca/shortageQA.asp. We contacted two
industry experts, Dave Goss of the American Coal Ash Association and Barry Deschenaux of Holcim Cement, to elaborate on this trend (increased
use of coal ash in cement due to domestic and foreign demand), but neither was able to provide more detailed information on the extent to which
this might occur in the future.
39 Mercury-CCP dialogue meeting summary document, Final Draft, 1/14/08
40 Energy and Environment Research Center (EERC), April 2006. Review of Florida Regulations, Standards, and Practices Related to the Use of Coal
Combustion Products. 2006-EERC-04-03. University of North Dakota, Grand Forks, ND.
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The Texas CCP review also notes that emissions control in the electric utility industry has had a
subsequent impact on the type, quantity, and quality of the solid materials produced at a specific power
plant41. Officials indicate that the reduced supply of high quality coal fly ash already poses a threat to coal
fly ash use in TX DOT projects, where high volumes of consistent quality coal fly ash are needed over the
duration of large, long-term projects.
Overall, technology options are available to the industry, specifically for the application of NOx controls,
which would minimize any impacts on the quality of fly ash. Furthermore, technology solutions are
currently being developed and deployed in the industry to minimize or avoid any such impacts from the
use of mercury controls as well.
Gypsum Wallboard
FGD gypsum is a product derived from the wet FGD process. Utilization of FGD gypsum in wallboard
manufacture is a well-established market. Because the quality of FGD gypsum produced by power plants
is generally consistent, new wallboard facilities often locate adjacent to power plants to allow FGD
gypsum to be delivered directly to the wallboard plants. In some cases, wet FGD gypsum is piped directly
to the adjacent wallboard facility, a step that significantly reduces transport and handling costs. Given
these developments, the demand for FGD gypsum will likely remain high, and may increase as new
wallboard manufacturing facilities are being constructed to accommodate FGD gypsum in wallboard
production.42
Structural Fill
Structural fill is an engineered material used to raise or change the surface contour of an area and to
provide ground support beneath highway roadbeds, pavements, embankments and building foundations.
The quality and engineering standards for use of CCPs in structural fill are less stringent than the
standards for structural applications such as concrete. Consequently, CCPs destined for use in structural
fill generally do not require processing, which keeps costs low.
Demand for CCPs in structural fill applications is variable and generally occurs on a project-by-project
basis. One large construction project using CCPs in fill can create a spike in demand for CCPs, but this
may be followed by a lull in demand until another sizeable project can be identified.43 Because CCPs are
generated continuously, the generator's or marketer's capacity to store and accumulate the material
between projects is a significant determinant in the use of CCPs in structural fill.
IMPACTS OF CURRENT POLICY SETTING ON MARKET DYNAMICS
While states play a primary role in establishing industrial waste regulations and guidance, EPA has an
opportunity to provide coordination and assistance at the national and regional levels to help achieve a
shift in waste management policy. EPA is currently engaged in several long-term efforts to increase
beneficial use of CCPs.
Under the RCC, EPA established goals for beneficial use of CCPs (as enumerated in the introduction) and
established the Coal Combustion Products Partnership (C2P2) to help reach these goals. C2P2 is a
cooperative effort among EPA, ACAA, the Utility Solid Waste Activities Group (USWAG), the U.S.
41 Energy and Environment Research Center (EERC), January 2005. Review of Texas Regulations, Standards, and Practices Related to the Use of Coal
Combustion Products. 2005-EERC-01-01. University of North Dakota, Grand Forks, ND.
42 Electric Power Research Institute, "Environmental Focus: Flue Gas Desulfurization By-Products," 1999.
43 Personal communication with David Goss, American Coal Ash Association, March 2006.
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Department of Energy (DOE), the U.S. Federal Highway Administration (FHWA), the Agricultural
Research Service of USDA, and the Electric Power Research Institute (EPRI). Through C2P2, EPA and
its co-sponsors work with all levels of government, as well as industry organizations, to identify and
address regulatory, institutional, economic, and other limiting factors to the beneficial use of CCPs. One
important overarching barrier addressed by C2P2 is the lack of information about beneficial use
opportunities. Specifically, the program includes the following initiatives and activities:
The C2P2 Challenge: Under the C2P2 challenge, partners are eligible for awards recognizing
activities such as documented increases in CCP use and successes in CCP promotion and
utilization.
Barrier Breaking Activities: C2P2 addresses limiting factors to increased CCP utilization
through activities such as developing booklets and web resources on the benefits and impacts of
using CCPs in highway and building construction applications; publishing case studies on
successful beneficial use of CCPs; supporting Green Highways; and updating a manual for
highway engineers on the use of fly ash in highway applications.
Technical Assistance: C2P2 has conducted a series of workshops with FHWA, EPA, DOE,
ACAA and other partners to provide technical assistance and outreach to support the use of CCPs
in concrete highway construction. These workshops present the technical feasibility of using
CCPs and the economic and environmental benefits that result from their use.
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CHAPTER 4: IMPACTS ASSOCIATED WITH BENEFICIAL USE OF
CCPs
To evaluate EPA's efforts to improve the beneficial use of CCPs, it is essential to quantify the important
environmental and human health impacts of increased use of these materials in various beneficial use
applications. An initial step in this process is describing the incremental environmental impacts associated
with using a specific quantity (e.g., one ton) of CCPs in different applications. These impacts can then be
extrapolated in specific scenarios designed to address program-level outcomes. Life cycle analysis (LCA)
represents a proven methodology for describing the impacts of beneficial use of specific quantities of
material, and can also inform a broader evaluation of program achievements.
This chapter first provides a brief overview of the use of LCA in the assessment of environmental impacts
of beneficial use, and also discusses the relationship between LCA and the economic analysis of net
social benefits. Next, the chapter identifies several available LCA tools that can be used to provide
insights into the impacts of beneficial use of CCPs in different applications, and presents an initial life
cycle analysis of the potential impacts associated with the use of one ton of fly ash and FGD gypsum in
concrete and wallboard manufacture, respectively. Finally, we note key limitations of this initial
assessment and identify areas for additional research.
LIFE CYCLE ANALYSIS AND RCC PROGRAM OUTCOMES
Life cycle analysis depicts the production of materials as a system of complex physical outcomes, and can
predict the incremental physical consequences of a change in material inputs, technology, waste
management practices, or price incentives. In LCA, as in reality, one change in the physical system, such
as the substitution of fly ash for virgin portland cement, leads to a corresponding cascade of economy-
wide impacts and shifts. As inputs are substituted, technologies, physical outputs, and exposure pathways
change. Using a range of modeling platforms and life cycle inventories to calculate the outputs associated
with each intermediate change, LCA calculates the net result of all of these interactions, capturing the
total incremental effect of a change in operations on physical environmental impacts such as air
emissions, and energy and water use. Life cycle analysis can be an effective performance assessment tool,
and because it is a systems approach to assessment, it represents an improvement over less comprehensive
techniques.
The RCC is designed to help facilitate changes in the economics and practice of waste generation,
handling, and disposal (e.g., by promoting market opportunities for beneficial use). The outcomes of the
program, therefore, can be described as the changes in total environmental impacts that result from
changes in beneficial use. Many of these impacts likely come from avoiding the production of virgin
materials that would be used in the absence of industrial materials. In some cases, changes in materials
use may also lead to (positive and negative) changes in processing, product performance, and disposal
approaches. LCA can, given appropriate data and modeling scenarios, describe the net impacts of all of
these changes, and can, therefore, provide an assessment of program results.
Life Cycle Analysis and Economic Benefit Assessment
As a tool for measuring physical impacts of system changes, LCA is a natural starting point in the
assessment of the economic benefits of a program, but it is important to distinguish between LCA and
economic benefits analysis. LCA is useful in the context of benefits analysis because it reflects a systems
approach, allows measurement of changes to baseline conditions, identifies tradeoffs, and yields concrete,
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measurable metrics that can be evaluated both in isolation and comparatively, across programs and
activities.
However, while it can provide a clear assessment of beneficial (and other) program impacts, LCA does
not itself measure the social benefits and costs of changes in practice, for two reasons. First, LCA
provides a static examination of impacts based on a one-time change to a system, and does not attempt to
measure net impacts over time, adjusting for long-term market responses (e.g., changes in price and
behavior) that can, in turn, affect the long-term system operation.44 Beneficial use of large-volume CCP
materials, such as fly ash and FGD gypsum, is already well-established. Therefore, gradual increases in
use of these materials may have some impact on the large cement and gypsum markets in the U.S., but
this analysis assumes that dramatic near-term changes in the market are unlikely. Therefore, the impacts
estimated by LCA are reasonable representations of total market impacts. However, if sudden, large-
scale changes in production of raw materials occur as a result of RCC efforts, then a net economic impact
analysis using methods like partial equilibrium analysis might be necessary.
Second, a complete assessment of the net economic benefits of a program requires the application of
economic valuation techniques to the physical outputs of LCA analysis, in order to describe, in economic
terms, what the physical outcomes imply for human well-being. For example, an LCA can describe
changes in the quantity of water used or waste generated in a process, but is not designed to identify the
effect of these impacts on well-being.45 Economic valuation of these changes depends upon the specific
location, timing, and quality of the water that is consumed or waste disposal that occurs. The value of
that water depends on how it would otherwise be used (e.g., for human consumption, industrial uses,
habitat support, irrigation) and the "value" of the waste depends on the health risks it poses, release
scenarios, and the people exposed.46
Ideally, LCA would be incorporated into a full-scale analysis of net program benefits that would account
for market responses and would value specific environmental impacts such as decreased releases of
pollutants. Unfortunately, the translation of physical changes into economic outcomes is typically costly,
difficult, and often controversial when applied to human health or environmental outcomes. It frequently
requires location-specific data on releases and exposures, as well as well-documented links between these
exposures and health or environmental impacts. Assigning an economic value to even a small set of
physical impacts can be a significant and expensive undertaking.47
44For example, a beneficial use that has a significant impact on raw material demand (e.g., for virgin aggregate) and on electricity demand may
ultimately affect the local prices of both energy and raw materials as demand for these commodities drops. The price changes could, in turn,
result in other changes in practice (e.g., decisions on the part of other purchasers to buy more aggregate or changes in use patterns of
electricity). These impacts would likely have some impact on the net change in environmental impacts measured in the LCA.
45 Life cycle analysis can incorporate impact assessments using a range of different methods that can, at a minimum, provide comparative
descriptions of the types of damage likely associated (or avoided by) the system change. However, valuation of specific impacts (e.g., health
impacts from air releases) requires modeling of specific exposure scenarios; LCA is designed specifically to address systems without requiring
unique location-specific information.
45 Hendrickson, Lave, and Matthews (2006) notes the limitation of LCA outputs that are not linked to specific locations and exposures - "A typical
[Life Cycle Inventory] of air pollution results in estimates of conventional, hazardous, toxic, and greenhouse gas emissions to the air. Even
focused on this small subset of environmental effects, it is unclear how to make sense of the multiple outputs and further how to make a
judgment as to tradeoffs or substitutions of pollutants among alternative designs."
47 In the ecological realm, these kinds of translations are underdeveloped. The agency is aware of this ongoing limitation. For example, this
conclusion has been drawn from several recent SAB reports, including EPA-SAB. 2003. "Underground Storage Tanks (LIST) Cleanup 6t Resource
Conservation ft Recovery Act (RCRA) Subtitle C Program Benefits, Costs, ft Impacts (BCI) Assessments: An SAB Advisory." (EPA-SAB-EC-ADV-03-001)
and "Advisory on EPA's Superfund Benefits Analysis." (EPA-SAB-ADV-06-002). In addition, the SAB Committee on Valuing the Protection of
Ecological Systems and Services is currently examining methods for addressing these limitations.
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Accordingly, LCA can represent not only a necessary ingredient, but also a practical initial alternative to a
complete economic benefit assessment. While net economic benefits are often the target performance
measure, it is necessary in many cases to rely on simpler proxies to facilitate management and
performance assessment. As proxies, LCA outputs can represent a legitimate and defensible measure of
program impacts. Therefore, we use LCA to investigate the measurable beneficial impacts associated with
RCC program achievements, using available LCA tools. A more detailed discussion of the role of LCA
in economic benefits assessment is provided in Appendix B.
ASSESSMENT OF BENEFICIAL IMPACTS OF CCP USE
To fully capture the beneficial impacts of C2P2 program achievements, it would be necessary to model
each beneficial use application of all CCPs targeted by the RCC. However, the time, data, and resources
required to perform this task are beyond the scope of this report. For this preliminary analysis, we have
selected two common CCPs, fly ash and FGD gypsum, which have well-understood beneficial use
applications and processes, and for which life cycle models and existing data are available.
We conducted a comprehensive review of available data sources and tools for assessing life cycle benefits
of beneficial use of these materials across all possible use applications. We identified four models that
support specific evaluation of the environmental impacts of avoided virgin materials extraction in
processes where CCPs are beneficially used in place of virgin materials:
Building for Environmental and Economic Sustainability (BEES) was developed by the
National Institute of Standards and Technology (NIST) with support from the U.S. EPA to allow
designers, builders, and product manufacturers to compare the life cycle environmental, and
economic performance of alternative building products.48 The BEES methodology measures
environmental performance using an LCA approach, following guidance in the International
Standards Organization 14040 series of standards for LCA. Thus, all stages in the life of the
product are analyzed: raw material acquisition, manufacture, transportation, installation, use, and
recycling and waste management. The BEES model is implemented in publicly available
decision-support software, complete with actual environmental and economic performance data
for a number of building products.
SimaPro was developed by the Dutch company Pre Consultants and can be used to perform
detailed lifecycle analyses of complex products and processes. SimaPro provides a high degree of
modeling flexibility in that it provides data profiles representing thousands of materials
production, transport, energy production, product use and waste management processes that can
be combined to model very specific systems. Thus, SimaPro relies on the user's understanding of
the various lifecycle stages and processes in the system being modeled. Results can be displayed
as lifecycle inventory flows (e.g. energy use, water use and pollutant emissions (for a variety of
pollutants including the criteria pollutants). In addition, one of several impact assessment
methods can be applied to characterize the environmental damages (e.g., global warming,
eutrophication, etc.) associated with these flows.
Pavement Life Cycle Assessment Tool for Environmental and Economic Effects (PaLATE)
is an Excel-based tool developed by the Consortium for Green Design and Manufacturing at U.C.
Berkeley for life cycle analysis of environmental and economic performance of pavements and
8 The BEES model and supporting documentation are accessible at: http://www.bfrl.nist.gov/oae/software/bees.html.
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roads. The model was developed for pavement designers and engineers, transportation agency
decision-makers, civil engineers, and researchers. PaLATE can evaluate the relative impacts of
using different virgin and secondary materials in the construction and maintenance of roads.
Based on user-specified data on the type and quantity of initial construction materials, road
construction equipment (e.g., asphalt paver), material transportation distances and modes,
maintenance materials and processes, and off-site processing equipment (e.g., rock crusher),
PaLATE calculates twelve life cycle inventory flows including water and energy use,
conventional air emissions (NOx, SO2, CO2, PMi0, and CO), toxic air emissions (Pb and Hg),
RCRA hazardous waste generation; and cancer and non-cancer Human Toxicity Potentials.49
The WAste Reduction Model (WARM) was created by EPA to help solid waste planners and
organizations estimate greenhouse gas (GHG) emission reductions from several different waste
management practices. WARM calculates GHG emissions for baseline and alternative waste
management practices, including source reduction, recycling, combustion, composting, and
landfilling. The user can construct various scenarios by entering data on the amount of waste
handled by material type and by management practice. WARM then automatically applies
material-specific emission factors for each management practice to calculate the GHG emissions
and energy savings of each scenario. In addition, the model will convert these outputs to
equivalent metrics including the equivalent number of cars removed from the road in one year,
the equivalent number of avoided barrels of oil burned, and the equivalent number of avoided
gallons of gasoline consumed.
All four models support life cycle analysis of various CCPs. PaLATE, BEES and WARM all include life
cycle data to evaluate use of fly ash as a substitute for finished portland cement in concrete, and SimaPro
supports evaluation of use of FGD gypsum in wallboard. We select BEES and SimaPro to evaluate fly
ash and FGD gypsum beneficial use because these models have been peer-reviewed and evaluate a large
suite of environmental metrics.50 In contrast, PaLATE has not undergone a formal peer review process,
and WARM evaluates only greenhouse gas metrics. For comparative purposes, however, we present the
results of a WARM analysis of the use of fly ash in concrete in Appendix C.51
In addition to BEES and SimaPro, the U.S. Economic Input-Output Life Cycle Assessment (EIO-LCA)
model provides an alternative approach for measuring the avoided upstream impacts of recycling. EIO-
LCA was developed at Carnegie Mellon University and provides the capacity to evaluate economic and
environmental effects across the supply chain for any of 491 industry sectors in the U.S. economy. EIO-
LCA also can represent the supply chain use of inputs and resulting environmental outputs across the
supply chain by using publicly available data sources from the U.S. government. By integrating
economic data on the existing flow of commerce between commodity sectors with environmental data on
releases and material flows generated by each sector, it is possible to estimate the additional
environmental emissions caused by an increase in production within a particular sector, accounting for
49 PaLATE does not allow for life cycle assessment of the inventory results, but in other life cycle models, impact assessment methods can be
applied to inventory results to estimate environmental damages.
50 BEES has reliable data for the use of fly ash in concrete, but it does not evaluate use of FGD gypsum in wallboard. SimaPro does allow evaluation
of both fly ash and FGD gypsum but we prefer the U.S.-based data in BEES to conduct the fly ash analysis. For this reason, we do not use the same
model for both analyses.
51 The PaLATE model was used to evaluate beneficial use of fly ash in previous iterations of this report, but we omit the PaLATE analysis from this
version in order to avoid comparisons of peer reviewed model findings to non-peer reviewed model findings for CCPs. It is important to note,
however, that PaLATE relies on much of the same LCI data as the EIO-LCA model, which is presented in Appendix C.
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changes in the supply chain. This approach can be used to provide insight into the sectors of the economy
that drive the environmental impacts of a given process, and shed light on the specific impacts of
particular policy efforts. While it is very helpful in examining the distribution of impacts across
economic sectors, the EIO-LCA is not optimal for a specific life cycle analysis of beneficial use of FGD
gypsum in wallboard because the life cycle impacts are modeled at the sector level and do not provide the
same process-level resolution that can be estimated for various use applications using SimaPro. EIO-LCA
is more useful for modeling use of fly ash in concrete, as it includes data for a fairly homogenous cement
sector. It is also important to note that EIO-LCA is a dollar-based model and thus, is not directly
comparable to the BEES/SimaPro data that is presented in tons. Appendix C describes supply chain
manufacturing impacts for cement and gypsum production modeled using EIO-LCA.
METHODOLOGY FOR EVALUATING UNIT IMPACTS OF BENEFICIAL USE
We conduct separate analyses to evaluate the incremental environmental impacts associated with
beneficially using a specific quantity (i.e., one ton) of fly ash and FGD gypsum. We employ:
BEES to investigate using one ton of fly ash as a substitute for finished portland cement in
concrete; and
SimaPro to investigate using one ton of FGD gypsum as substitute for virgin gypsum in
wallboard.
The first step in evaluating the life cycle impacts of beneficial use of fly ash and FGD gypsum is
development of environmental impact profiles for use of one ton of each material as a substitute for
portland cement in concrete and for virgin gypsum in wallboard, respectively. One ton was selected as the
unit-basis for these analyses because the impacts can then easily be extrapolated to current use quantities,
which are reported by the American Coal Ash Association (ACAA) in tons. In addition, by developing
life cycle benefits profiles for use of a consistent quantity of each material, the impact profiles of specific
materials can be compared with each other.
The calculation of unit impact values for fly ash and FGD gypsum are described in greater detail below.
To the extent possible, we attempt to use comparable assumptions and life cycle system boundaries in
both analyses.
BEES Analysis of Use of Fly Ash in Concrete
BEES includes environmental performance data for a number of concrete products (e.g., concrete
columns, beams, walls, and slab on grade). The user can compare the environmental performance data of
each of these products using different pre-determined concrete mix-designs, some of which include fly
ash. The BEES environmental performance data serve as quantified estimates of the energy and resource
flows going into the product and the releases to the environment coming from the product, summed
across all stages of the product life cycle for one cubic yard of concrete. BEES quantifies these flows for
hundreds of environmental metrics, but to capture the general spectrum of impacts, we focus on the
following:
Total primary energy use (MJ);
Renewable energy use (MJ);
Nonrenewable energy use (MJ);
Water use (liters);
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Atmospheric emissions (CO2, methane, CO, NOx, SOx, particulates, Hg, Pb) (grams);
Waterborne waste (suspended matter, biological oxygen demand, chemical oxygen demand, Hg,
Pb, selenium; and
Nonhazardous waste (kg).
As an example of the LCA approach, we assess the beneficial environmental impacts of using fly ash to
offset virgin cement inputs in a concrete beam with a compressive strength of 4 KSI (4,000 psi) and a
lifespan of 75 years. It is important to note that this concrete product was selected to represent use of fly
ash in any generic concrete application; the unit impact values do not reflect any assumptions specific to
the life cycle of a concrete beam in BEES.52 Furthermore, any concrete building product data set could
have been used without changing the unit impact value. For further details on the life cycle inventory data
used in this analysis, refer to Appendix D.
The benefits of fly ash use are measured as the difference in environmental impacts between a baseline
scenario and a beneficial use scenario. In the baseline scenario, a one cubic yard 4 KSI concrete beam is
produced using 100% portland cement. In the beneficial use scenario, a one cubic yard 4 KSI concrete
beam is produced using 15% coal fly ash and 85% portland cement.53'54 The difference in environmental
impacts between the baseline and beneficial use scenarios represents the change in impacts from
substituting 15% of the portland cement with fly ash in one cubic yard of 4 KSI concrete. We translate
these impacts from a cubic yard concrete basis to a ton fly ash basis by dividing the impacts by the
absolute quantity of fly ash in one cubic yard of the concrete product. For an illustration of this
methodology, refer to Appendix D.
SimaPro Analysis of FGD Gypsum in Wallboard
We calculate the unit impacts of using FGD gypsum in place of virgin gypsum stucco in wallboard as the
difference in impacts between wallboard made with 100% virgin gypsum and wallboard made with 100%
FGD gypsum. We model these impacts as one ton of avoided "stucco" manufacture in SimaPro.55 Stucco
is the term used in SimaPro to describe the gypsum material used in wallboard. We selected the
Ecolnvent data set because it includes gypsum mining but also includes the processing of gypsum for use
in wallboard (i.e., burning of gypsum and milling of stucco for use in gypsum wallboard). Thus, this
dataset includes all the processes that would be avoided if an equivalent quantity of FGD gypsum were
used in place of stucco in wallboard. The production of FGD gypsum from coal combustion is not
modeled, as discussed in the following section on allocation of life cycle impacts to FGD gypsum. In
addition, this analysis assumes that FGD gypsum dewatering occurs via holding ponds and that the
environmental impacts of dewatering are negligible.56 This analysis also does not model transport
distance; we assume FGD gypsum would have the same transport distances to the construction site as
All concrete building product data in BEES (e.g., concrete columns, beams, walls, and slab on grade) use a 75-year lifespan assumption.
Calculating unit impact values using data from any one of these products yields the same values. In addition to life cycle inventory data for
concrete building products, BEES also includes data for a concrete parking lot pavement. The concrete parking lot data, however, use a 30-year
lifespan assumption; calculating unit impact values using pavement data yields values that are approximately 2.5 times greater than the values
calculated from building product data because the pavement data assume a 2.5 times shorter lifespan than building products.
53 Fly ash replaces portland cement in concrete in a one to one ratio based on mass.
M Both the concrete beam made with and without blended cement assume a 60-mile round trip transport distance for portland cement and fly ash
and a 50-mile round-trip transport distance for aggregate to the ready-mix concrete plant.
55 We use the Ecolnvent data set titled "Stucco, at plant/CH U" for this purpose.
56 There may actually be emissions/dusting impacts associated with dewatering in a holding pond, but we have been unable to identify quantified
estimates of these impacts. Alternatively, dewatering may be accomplished through mechanical processes but we were also unable to identify the
energy impacts of mechanical dewatering.
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virgin gypsum.57 Thus, avoided gypsum mining and avoided processing of gypsum into stucco, as
represented by the Ecolnvent stucco manufacturing data set, are the only lifecycle stages modeled in
SimaPro. Appendix D provides more information on the FGD gypsum analysis.
Allocation of Life Cycle Impacts to CCPs
As EPA programs evolve to emphasize both beneficial use of industrial materials and life cycle analysis
approaches to evaluating these programs, it is important to consider upstream impacts of the processes
that create beneficial use materials, including, in this case, the impacts of the electrical power generation
industry that produces CCPs for beneficial use.
The beneficial use of CCPs has positive environmental and energy impacts relative to landfilling and
virgin material production. Consideration of the negative upstream impacts of electricity production
through "allocation" does not actually reduce the beneficial impacts of beneficial use, nor does it "create"
negative impacts. Instead, it represents a quantitative way of recognizing that CCPs are associated with
the generation of coal-fired power and not an environmentally "free" product.
Analysis of life cycle impacts is, in its simplest form, the calculation of all impacts associated with a
single production system (e.g., the manufacture of paper, or the production of energy using coal).
However, when one production system (or a set of linked production systems) makes two or more
products with market value (i.e., co-products), it is accepted practice in life cycle analysis to recognize
that these products are associated with environmental impacts, and to allocate the total life cycle
production impacts across these products.58 Several methods for allocation are possible, depending on the
system(s), inputs, and the quantity and value of co-products. Simple methods include allocating impacts
proportionately by total mass or by market value; more complex methods may be necessary when
integrated systems use different types of inputs or produce a range of products with different features and
environmental profiles.
Waste is not considered a co-product, and it is, therefore, generally unnecessary to allocate specific
production impacts to materials that are destined for disposal (disposal impacts are allocated 100% to the
producing industry). However, when an industrial material becomes a beneficial use material and ceases
to be considered a waste, it reflects a market value. It is, therefore, a co-product, though typically a very
low-value one when compared to the primary products of the industry (in this case, electricity). It is
important to consider whether co-products of electricity generation (such as fly ash and FGD gypsum)
that are beneficially used should have some portion of the production impacts associated with coal
combustion (e.g., energy use, greenhouse gas equivalents, releases to air and water) attributed to them.59
In Appendix E, we provide an illustration of a potential approach for allocating the environmental and
energy impacts from coal-fired power generation across electricity generation and CCPs. The analysis
considers some hypothetical macro-level scenarios for coal-fired power generation, as well as macro-level
flows of several key CCPs. The preliminary analysis in Appendix E is designed to assess the implications
57 We do not model a transport differential between virgin and FGD gypsum to be consistent with the transport assumptions used in the BEES fly ash
analysis, which helps preserve the comparability of the fly ash and FGD gypsum unit impact values. It is important to note, however, that an
increasing number of new gypsum wallboard plants are being constructed adjacent to coal-fired power plants, so the transport distance of FGD
gypsum to the wallboard manufacturing facility may, in some cases, be less than the transport distance of virgin gypsum.
58 A discussion of general principals for allocation is presented in the International Standard on Environmental ManagementLife Cycle Assessment-
Goal and scope definition and inventory analysis (ISO 14041:1(E)), pp.11-12, and Annex B.
59 It is important to stress that allocated impacts are not actual impacts associated with the beneficial use of the materials; in most cases use is
significantly more beneficial than disposal. Instead, allocation is a means of placing the beneficial use materials in the context of their original
production and recognizing that the processes that produce these byproducts may incur environmental costs.
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of allocating the environmental effects of power generation to both the energy product and the CCPs.
Using both an economic and a mass-based approach, we find that the only small flows would be allocated
to the CCPs relative to the impacts of electricity production (i.e. less than one percent in the case of mass-
based allocation).
Because of the small environmental impacts allocation indicated by our preliminary analysis in Appendix
E, and because of high uncertainty associated with fuel sources, prices of electricity generation, and CCP
prices, we do not currently include either an economic or mass-based allocation of coal combustion
impacts to fly ash or FGD gypsum into this analysis. However, to fully understand the potential impacts
of beneficial use on coal combustion, and to fully characterize the benefits associated with beneficial use,
it may be important to assess these impacts under various analytical scenarios as the program moves
forward.
Typically, as with fly ash and FGD gypsum, the economic value of beneficial use materials is small in
comparison to the value of primary products of the producing industries. However, it is conceivable that
significant increases in the value of beneficial use materials could alter the economics of the producing
industries. While it is unlikely that any industry would alter production to increase production of
beneficial use materials, demand for these materials could improve the cost structure of certain industrial
processes. For example, increased demand for CCPs could improve the cost structure for coal-fired power
plants and improve their competitive position in energy markets.60 As beneficial use and the economic
value of various industrial materials increases, it becomes increasingly important to accurately account for
the processes that produce the materials as well as the processes that use them.
RESULTS
For both the baseline and beneficial use scenarios, BEES and SimaPro generate quantitative estimates of
impacts for a suite of environmental metrics. For each metric, environmental outputs under the baseline
and beneficial use scenarios represent life cycle impacts of replacing virgin materials with CCPs. Where
this difference is positive, the impact is an environmental benefit of using CCPs in place of virgin
materials. Where the difference is negative, use of CCPs suggests a decline in environmental quality.
Exhibit 4-1 presents the results of the analyses of use of fly ash in concrete and use of FGD gypsum in
wallboard.
60 An example of a system in which dramatic changes in co-product value have driven production changes is the recent change in demand for
ethanol, which has resulted in a significant increase in demand for agricultural by-products and has altered production decisions to meet this new
demand.
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EXHIBIT 4-1: LIFECYCLE ASSESSMENT OF POTENTIAL IMPACTS OF CCP BENEFICIAL USE
AVOIDED IMPACTS
PER 1 TON FLY ASH AS PORTLAND
CEMENT IN CONCRETE
PER 1 TON FGD GYPSUM IN
WALLBOARD
ENERGY USE
MGNRENEWABLE ENERGY (Mjl*
RENEWABLE ENERGY (Mjf
TOTAL PRIMARY ENERGY (MJf
TOTAL PRIMARY ENERGY (US$}'f
WATER USE
TOTAL WATER USE (L)
TOTAL WATER USE (US$f
GREENHOUSE GAS EMISSIONS
CO, (G)
METHANE (G)
AIR EMISSIONS
CO {G}
NOX (G)
SOX (G)
PARTICULATES GREATER THAN PM,,, (G)
PARTICULATES LESS THAN OR EQUAL TO PM,,, (G)
PARTICULATES UNSPECIFIED (G)
MERCURY (G)
.EAD (G)
WATERBORNE WASTES
USPENDED MATTER (G)
BIOLOGICAL OXYGEN DEMAND (G)
CHEMICAL OXYGEN DEMAND (G)
COPPER (G)
MERCURY(G)
LEAD (G)
ELENIUM (G)
NONHAZARDOUS WASTE (KG)'
4,214.18
43.55
4,259.29
119.26
341.56
0.22
636,170.21
539.49
593.45
1,932.48
1,518.21
0.00
0.01
1,745.25
0.04
0.03
13.96
3.07
26.00
0.00
0.00
0.00
0.00
0.00
12,568.97
13.69
12,582.66
352.31
14,214.60
9.01
77,754.24
175.51
39.06
168.02
139.14
1,194.25
520.93
17.11
0.00
0.03
23.60
21.87
24.71
0.02
0.00
0.01
0.00
3.12
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AVOIDED IMPACTS
PER 1 TON FLY ASH AS PORTLAND
CEMENT IN CONCRETE
PER 1 TON FGD GYPSUM IN
WALLBOARD
Notes:
a. Nonrenewable energy refers to energy derived from fossil fuels such as coal, natural gas and oil.
b. Renewable energy refers to energy derived from renewable sources, but BEES does not specify what sources these include.
Total primary energy refers to the sum of nonrenewable and renewable energy.
In addition to reporting energy impacts in megajoules (MJ), we monetize impacts by multiplying model outputs in MJ by the
average cost of electricity in 2006 ($0.0275/MJ), converted to 2007 dollars ($0.0280/MJ). The 2006 cost of energy is taken
from the Federal Register, February 27, 2006, accessed at: http://www.npga.org/14a/pages/index.cfm?pageid=914. The cost
was converted to 2007 dollars using NASA's Gross Domestic Product Deflator Inflation Calculator, accessed at:
http://cost.isc.nasa.gov/inflateGDP.html.
In addition to reporting water impacts in gallons, we monetize impacts by converting model outputs from liters to gallons and
multiplying by the average cost per gallon of water between July 2004 and July 2005 ($0.0023/gal), converted to 2007 dollars
($0.0024/gal). The 2005 cost of water is taken from NUS Consulting Group, accessed at:
https://www.energyvortex.com/files/NUS_quick_click.pdf. The cost was converted to 2007 dollars using NASA's Gross
Domestic Product Deflator Inflation Calculator, accessed at: http://cost.isc.nasa.gov/inflateGDP.html.
f. BEES reports waste as "end of life waste." In contrast, SimaPro reports "solid waste." In is not clear if these waste metrics are
directly comparable as SimaPro does not specify whether "solid waste" refers to manufacturing waste, end-of-life waste, or
both.
As shown in Exhibit 4-1, the results of the fly ash and FGD gypsum analyses suggest many positive
environmental impacts associated with beneficial use. For most metrics, there is a significant difference
between the unit impact value for fly ash and FGD gypsum. The difference in unit impact values reflects
different avoided processes when fly ash is used to offset portland cement versus when FGD gypsum is
used to offset virgin gypsum. For example, the primary driver of benefits when fly ash is used in concrete
is avoided raw materials extraction and avoided portland cement production.61 In comparison, the primary
driver of benefits when FGD gypsum is used in wallboard is avoided virgin gypsum extraction and the
processing of virgin gypsum into stucco. Portland cement production generates relatively high greenhouse
gas emissions. Thus, the avoided CO2 and methane emissions are greater for fly ash than for FGD
gypsum in this analysis. In contrast, gypsum mining requires comparatively higher quantities of water, so
the water savings are greater for FGD gypsum in this analysis than for portland cement.
In addition, the difference in unit impacts may reflect differences in the assumed system boundaries
between the two analyses. It is unclear how the BEES system boundaries compare to SimaPro. Thus, the
total life cycle impacts calculated in BEES could be large or small in comparison to the system
boundaries in the SimaPro FGD gypsum analysis.
LIMITATIONS AND ASSUMPTIONS
Although the BEES analysis provides a useful example of the benefits that can be achieved through
beneficial use of fly ash in concrete, it is important to recognize some of the key limitations and
assumptions of the work to date:
The BEES model may over- or underestimate the national impacts of using fly ash in concrete
construction projects because site-specific environmental conditions and proximity to sources of
fly ash may affect the resulting benefits and influence the net effect of choosing fly ash over
portland cement.
61 It is unclear from the documentation provided for BEES what impacts (e.g. virgin materials extraction, plant infrastructure, etc.) are modeled for
portland cement production. For this reason, it is not possible to explain the differences in unit impact results between the FGD gypsum and fly
ash analysis.
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BEES assumes round-trip distances for the transport of concrete raw materials to the ready-mix
plant of 60 miles for portland cement and fly ash and 50 miles for aggregate. The user cannot
adjust these transport distances. This analysis also assumes the minimum possible transport
distances for the finished concrete products to the construction site. This transport distance for
ready-mix concrete for a pavement application is 50 miles.
BEES environmental results are reported in physical quantities (e.g., MJ energy, liters water, g
CO, g NO, g Hg, etc.), not in monetized terms.
In BEES, the calculation of each environmental impact is not fully transparent. BEES does
disaggregate the total life cycle impact value for each environmental metric (e.g., energy use, CO2
emissions, etc.) by lifecycle stage and by product component, but it is not possible to see exactly
how each impact is derived. This limits the user's ability to compare the results of the BEES
model with those of others models, such as SimaPro.
The FGD gypsum analysis is based on a Swiss life cycle inventory data. While we substituted
Swiss electricity data with the average U.S. energy mix, it is unclear whether the average U.S.
energy mix is an accurate representation of the electricity mix used in wallboard manufacturing.
Given the recent trend in new wallboard facilities being constructed adjacent to coal-fired
powered plants, it is possible that these facilities use primarily coal-based electricity. With the
exception of energy mix, it is unlikely that any other differences between European and U.S.
gypsum extraction and stucco processing would result in meaningful differences in environmental
impacts.
The FGD gypsum analysis assumes that dewatering of FGD gypsum is accomplished through
evaporation in holding ponds. To the extent that the predominant practice is to use mechanical
dewatering processes, the analysis should be modified to reflect this. The assumption of
dewatering via holding ponds likely overstates the energy and energy-related emissions impacts
in this analysis, since the impacts of dewatering, which are subtracted from the avoided gypsum
processing impacts, would be greater for mechanical dewatering than for holding pond
evaporation.
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CHAPTER 5: ESTIMATING PROGRAM LEVEL IMPACTS
This chapter provides an overview of an initial, life-cycle based approach to evaluating program level
impacts associated with the RCC effort to increase beneficial use of CCPs. The chapter first outlines two
critical steps necessary for a complete evaluation of specific program impacts:
Development of defensible beneficial use scenarios that reflect likely market trends, policy
efforts, and key limitations; and
Implementation of a well-supported attribution protocol for assigning beneficial use impacts to
specific EPA programs.
This discussion is followed by a preliminary analysis of the total impacts associated with current
(baseline) beneficial use patterns, based on an extrapolation of the life cycle analysis impacts identified in
Chapter 4. The purpose of this chapter is to present an initial estimate of the measurable impacts
associated with current levels of beneficial use of CCPs, and to outline the steps necessary to provide a
refined, program-specific analysis of EPA's efforts through the RCC to increase beneficial use of CCPs.
DEVELOPMENT OF DEFENSIBLE BENEFICIAL USE SCENARIOS
Life cycle inventories (LCI) and LCA provide comprehensive information on the impacts associated with
given quantities of materials used in specified systems. The impacts measured by LCA models are
typically linear; as the quantity of CCPs used in a particular application (e.g., concrete) is increased, the
environmental impacts increase proportionately.
While LCA can provide insights into the potential magnitude of program benefits, in some cases existing
market limitations and trends suggest that a linear extrapolation of current practices would be unrealistic.
An effective assessment of true program impacts requires the development of defensible market scenarios
that accurately identify the extent to which different beneficial uses are likely to increase, given the
realities of the existing and emerging markets for beneficial use and the structure of RCC programs.
Current Market Dynamics: Factors Affecting Beneficial Use
Several market factors can limit the increased beneficial use of CCPs in various products. In some cases
programs can be designed to address these factors effectively. Exhibit 5-1 outlines several of these
factors and presents hypothetical actions that might address them. It is important to note that the actions
described below are intended only to illustrate possible conditions for increasing the beneficial use of
CCPs; they do not represent specific policy recommendations or existing program priorities.
EXHIBIT 5-1: LIMITING FACTORS TO INCREASED BENEFICIAL USE OF CCPs
FACTOR TYPE
Economic
FACTORS AFFECTING
INCREASED BENEFICIAL USE
Transportation costs generally limit the shipment of
CCPs to within about a 50 to 1 50 mile radius of power
plants. In some cases, however, the cost of transport
to the end user may be prohibitively expensive.
In some parts of the country and for certain use
applications, the cost of virgin materials may be
cheaper than CCPs.
HYPOTHETICAL ACTIONS
TO INCREASE BENEFICIAL USE
Implementation of strategic actions to create
incentives to increase beneficial use by shifting
the economic drivers (i.e., cost of materials) in
favor of CCPs. Potential incentives could include
tax credits for the use of CCPs, increased CCP
landfill disposal tipping fees, or streamlining the
permitting process for facilities that use CCPs near
coal combustion plants (e.g., FGD gypsum plants).
5-1
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FACTOR TYPE
FACTORS AFFECTING
INCREASED BENEFICIAL USE
HYPOTHETICAL ACTIONS
TO INCREASE BENEFICIAL USE
Institutional
Technical
Educational
Sources:
Inexpensive landfill disposal can limit incentive to sell
rather than dispose of CCPs.
National standards organizations have promulgated
specifications that limit or disallow the use of CCPs in
some construction applications because of quality and
performance concerns and perceptions.
The implementation of the U.S. Clean Air Mercury Rule
(CAMR) may result in altering the chemical properties
of fly ash, rendering it unmarketable for beneficial
use.
Similar impacts may also occur for fly ash containing
higher levels of unburned carbon or other components
resulting from installation of low-NOx burners at coal-
based power plants.
Lack of consistency and quality in the production of fly
ash has resulted in limited use in the high-value ready-
mix concrete market. The priority at a coal-fired
power plant will always be on producing electricity,
not ash. A change in the combustion process, such as
the type of coal burned, results in a change in ash
quality, making it difficult to produce a consistent
product.
While quality and consistency of fly ash are legitimate
concerns of end-users, in some cases, negative
perceptions toward CCP use are unwarranted. Negative
perceptions can often be attributed to a single
experience using CCPs in a project that failed, even if
CCPs were not the cause of the failure. For example,
at one time, the Austin, TX concrete market almost
turned to an all-cement market because of one misuse
resulting from a lack of education about the material.
State DOTs rely on consensus standards for
guidance and generally accept the use of fly ash in
concrete. DOT projects can be used to
demonstrate the performance of CCPs in
geotechnical applications.
Establishment of a research and development
infrastructure to address the technical limiting
factors to CCP use.
Provide technical and/or economic assistance to
utilities using low-NOx burners to identify and
implement cost-effective process modifications or
new equipment to reduce the carbon content of
fly ash.
Taking into account the power plant's priority of
generating electricity, the program could facilitate
formal training programs to teach plant operators
about the co-product value of producing
consistent-quality fly ash.
Dissemination of objective, scientific material to
educate potential end users. (EPA is currently
addressing this through C2P2 and other activities).
I. U.S. Department of Energy, National Energy Technology Laboratory, "General Summary of State Regulations," accessed at:
http://www. netl.doe. gov/E£tWR/cub/states/select_state. html.
Energy and Environmental Research Center, "Barriers to the Increased Utilization of Coal Combustion/Desulfurization By-Products by
Government and Commercial Sectors-Update 1998," EERC Topical Report DE-FC21-93MC-30097--79, July 1999.
American Coal Ash Association, "Frequently Asked Questions," accessed at: http://www.acaa-usa.org/FAQ.htm.
Schwartz, Karen D. "The Outlook for CCPs," Electric Perspectives, July/August 2003.
Energy £t Environmental Research Center, University of North Dakota, "Review of Florida Regulations, Standards, and Practices Related to
the Use of Coal Combustion Products: Final Report," April 2006, accessed at: http://www.undeerc.org/carrc/Assets/TB-
FLStateReviewFinal.pdf.
Energy £t Environmental Research Center, University of North Dakota, "Review of Texas Regulations, Standards, and Practices Related to
the Use of Coal Combustion Products: Final Report," January 2005, accessed at:
http://www.undeerc.org/carrc/Assets/TXStateReviewFinalReport.pdf.
Exhibit 5-1 outlines a number of economic and non-economic factors that may limit the increased
beneficial use of CCPs. The economic factors primarily relate to transportation costs and the price of
virgin materials; a critical limitation of the market for CCPs may be the regional nature of the coal-
5-2
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burning industry and the extent to which CCPs can find viable markets competing with virgin materials
within an economically viable distance.
Several of the non-economic issues presented in Exhibit 5-1 may also limit the expansion of CCP
beneficial use, if, for example, new uses and new markets require changes in state policies governing
CCP use. In response, targeted efforts among states to harmonize policies regarding beneficial use of
CCPs could result in expansion of certain uses of CCPs.
To effectively describe impacts associated with RCC programs and goals, it is important to develop
scenarios that correctly identify the limits of existing markets, and calculate the quantitative impact on the
use of CCPs in different applications. In addition, scenarios should incorporate RCC priorities, in order
to better predict which uses and markets are likely to expand. At this time, data on market limitations and
on program priorities and goals are not refined enough to inform a detailed program analysis. However,
spatial information about coal-fired power plants and new data on emerging markets may be sufficient to
support an analysis in the near future. The result could be a set of scenarios that pinpoints specific uses
for CCPs that are likely to grow and notes regional and national limits for certain applications.
Structural Changes to the Market
In addition to changes related to market trends and program activities, beneficial use scenarios must, in
some cases, reflect significant changes to the market, such as large-scale technology shifts that might
affect demand for or production of CCPs. In addition, for materials frequently used in construction,
unexpected events such as large storms or terrorist attacks may result in sudden, regional changes in
demand if, for example, large quantities of materials are needed for reconstruction or if coal-fired power
plant operations change significantly as a result of a regional event.
Since these events are by definition unpredictable, it is important to identify methods for analyzing
impacts if and when they occur. In particular, analyses that clearly identify the current regional market
conditions (e.g., oversupply, strong demand) would provide a useful starting point for analysis of
unexpected market shifts.
ATTRIBUTION OF IMPACTS TO EPA PROGRAMS
The factors affecting increased beneficial use also link to the issue of attributing changes in beneficial use
markets or behavior to specific EPA initiatives. The issue of attribution is complex, and in many cases
the data necessary to support a clear attribution of impacts are not available. Particularly in the case of
voluntary programs, it is often difficult to attribute changes in behavior (or a proportion of the change in
behavior) to specific EPA activities. For example, changes in recycling or source reduction may be due
to outside forces (i.e., market dynamics), multiple government programs, or a combination of both.
One starting point in addressing the attribution of benefits to EPA activities is an examination of existing
information and methods describing the performance of target EPA programs and overall trends in
beneficial use. Linking program activity with market trends can, on a qualitative basis, provide an
indication of whether the program is having an effect. This initial scoping exercise can then be
supplemented with the development of specific program scenarios that endeavor to quantify incremental
beneficial use levels attributable to EPA's initiatives. In other cases, it may be necessary to start with the
assumption that all costs and all benefits are related to EPA activities, and adjust that assumption as
programs mature and data become available.
5-3
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A full-scale, defensible approach to attribution of voluntary program impacts, however, requires a clear
understanding of both the specific activities undertaken by the program and the differences between
behavior of program participants and those who do not participate. This information can sometimes be
obtained or identified through broadly collected data that includes both participants and non-participants
(e.g., the Biennial Report or the Toxics Release Inventory). In other cases, behavioral research can help
predict effective response rates to different types of programs. Exhibit 5-2 outlines the process for a full-
scale assessment of attribution.
EXHIBIT 5-2: OUTLINE TO ATTRIBUTE VOLUNTARY PROGRAM IMPACTS
STEP 1: ASSESS THE MARKET FAILURE BEING ADDRESSED
Identify and describe specific market failure of interest
Example: material with market value being disposed as waste
Evaluate size of market failure: evaluation of total quantity affected, current recovery and management,
potential economically feasible recovery
Identify key behavior changes necessary to address market failure
Identify programs in place to address market failure, including Federal, State, local, and private efforts.
STEP 2: DESCRIBE IN DETAIL EACH EPA PROGRAM WORKING ON THE "ISSUE"
Summarize program goals, structure, policy leverage points using program evaluation methodologies.
Identify, for each relevant program, current and intended participants, key resources available, actions taken
by participants, timeline for behavioral change, and link between activities and behavioral change.
STEP 3: IDENTIFY AVAILABLE DATA ON EPA AND OTHER EFFORTS
Quantitative estimates of recent trends in target behavior, specific estimates of recent changes in behavior
among EPA program members and non-members, and research on response rates for similar programs,
strategies.
STEP 4: ATTRIBUTION OF IMPACTS TO EPA PROGRAM(S)
Refine analysis of data collected in Step 3 to identify: changes in behavior among EPA program participants and
among non-members, expected leverage of EPA activities across federal, state, private programs (e.g., by
expansion of recycling efforts from pilot programs or harmonization of state regulations as a result of EPA
information development), and expected leverage of EPA activities over time.
Identify and correct for independent, confounding market changes that may affect the issue, such as changes in
virgin raw materials prices due to sudden shortage.
The result of this approach should yield a quantitative estimate of the total extent of changes that can be
attributed to EPA. Where implementation and/or tracking data are not available, approaches can
potentially include theoretical estimates reflecting literature on response rates for voluntary activities. As
necessary, this effort can also provide information to effectively allocate total EPA impacts across
multiple programs in cases where more than one program is focused on addressing the same market
failure. In areas where the attribution of outcomes is not possible due to data and methodological
limitations, program structure and purpose can be revisited with the intent of developing metrics (e.g., for
PART analysis) that are meaningful in measuring change without attempting to achieve a simplistic
success metric of "outcome/resources."
In the absence of specific information on behavior changes among participants and non-participants in
RCC beneficial use activities, we focus below on total impacts associated with CCP beneficial use. This
forms an upper bound estimate of the impact of EPA programs related to these materials, but may
understate total beneficial impacts because not all materials are considered.
5-4
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BENEFICIAL IMPACTS ASSOCIATED WITH CURRENT USE OF CCPs
In the absence of defensible beneficial use scenarios for CCPs or a well-supported allocation protocol for
assigning beneficial use impacts to specific EPA programs, we present a preliminary analysis of the total
impacts associated with current (baseline) beneficial use patterns. While these impacts do not strictly
reflect RCC program achievements, they represent the best available information on the environmental
benefits of beneficially using CCPs, and reflect the impacts of all EPA, state, and industry efforts to
increase CCP use to its 2005 level.
We calculate the beneficial impacts of current beneficial use of CCPs by extrapolating the life cycle
analysis impacts identified in Chapter 4 to the current quantity of CCPs beneficially used in each
application as presented in ACAA's 2005 CCP Survey. We also calculate the beneficial impacts of
achieving the RCC goal for beneficial use of fly ash (i.e., use of 18.6 million tons of fly ash in concrete by
2011). We are unable to similarly calculate RCC program achievements for increased use of FGD
gypsum as a program goal has not been developed for FGD gypsum. Exhibit 5-3 presents the impacts of
the beneficial use of fly ash and FGD gypsum extrapolated both to current use quantities and the RCC
goal for use of fly ash in concrete.
5-5
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EXHIBIT 5-3: EXTRAPOLATED IMPACTS OF THE BENEFICIAL USE OF CCPs
AVOIDED IMPACTS
ENERGY USE
NONRENEWABLE ENERGY (MJ)"
RENEWABLE ENERGY (MJ)'
TOTAL PRIMARY ENERGY (MJ)'!
TOTAL PRIMARY ENERGY (BTU)
TOTAL PRIMARY ENERGY (US$)h
FLY ASH IN
CONCRETE
EXTRAPOLATED TO
RCCGOAL(18.6
MILLION TONS)3
78.4 billion
810.0 million
79.2 billion
75 trillion
$2.2 billion
FLY ASH IN
CONCRETE
EXTRAPOLATED TO
CURRENT USE
(15.0 MILLION
TONS)"
63.2 billion
652.8 million
63.8 billion
60 trillion
$1 .8 billion
FGD GYPSUM IN
WALLBAORD
EXTAPOLATED TO
CURRENT USE (8.2
MILLION TONS)C
102.8 billion
111.9 million
102. 9 billion
98 trillion
$2.9 billion
PARTIAL SUM OF
CURRENT USE
BENEFICIAL
IMPACTS"
166.0 billion
764.7 million
166. 7 billion
1 58 trillion
$4.7 billion
WATER USE
TOTAL WATER USE (LITERS)
TOTAL WATER USE (US$)'
6.3 billion
$4.0 million
5.2 billion
$3.2 million
116.2 billion
$73.7 million
121 .4 billion
$77.9 million
GREENHOUSE GAS EMISSIONS
CO, (G)
METHANE (G)
TOMS CO? EQUIVALENT1
METRIC TONS CARBON
EQJJ 1 V AL ENT ( MT C E ) k
11.8 trillion
10.0 billion
13.2 million
3.6 million
9.5 trillion
8.1 billion
10.6 million
2.9 million
0.6 trillion
1 .4 billion
0.7 million
0.2 million
10.2 trillion
9.5 billion
11.5 million
3.1 million
AIR EMISSIONS
CO (G)
NOx (G)
SOx (G)
PARTiCLILATES GREATER THAN
PM,0 (G)
PARTiCLILATES LESS THAN OR
EQUAL TO PMm (G)
P ARTICULATES UNSPECIFIED
(G)
MERCURY (G)
LEAD (G)
11.0 billion
35.9 billion
28.2 billion
0
0.2 million
32.5 billion
714,000
523,000
8.9 billion
29.0 billion
22.8 billion
0
.02 million
26.1 billion
576,000
421,000
0.3 billion
1 .4 billion
1.1 billion
9.7 billion
4.3 million
0.1 billion
8,000
235,000
9.2 billion
30.3 billion
23.9 billion
9.7 billion
4.3 million
26.3 billion
584,000
656,000
WATERBORNE WASTES
SUSPENDED MATTER (G)
259.6 million
209.2 million
193.0 million
402.2 million
5-6
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AVOIDED IMPACTS
FLY ASH IN
CONCRETE
EXTRAPOLATED TO
RCCGOAL(18.6
MILLION TONS)3
FLY ASH IN
CONCRETE
EXTRAPOLATED TO
CURRENT USE
(15.0 MILLION
TONS)"
FGD GYPSUM IN
WALLBAORD
EXTAPOLATED TO
CURRENT USE (8.2
MILLION TONS)C
PARTIAL SUM OF
CURRENT USE
BENEFICIAL
IMPACTS"
(G)
57.1 million
483.6 million
0
1
0
46.1 million
389.7 million
0
0
0
NON-HAZARDOUS WASTE (KG)K
178.8 million
202.1 million
194,000
3,000
65,000
2,000
25.4 million
224.9 million
591.8 million
194,000
3,000
65,000
2,000
25.4 million
Notes:
a. We extrapolate the incremental impacts (i.e., impacts associated with use of 1 ton fly ash) to estimate impacts of attaining
the RCC goal for the use of fly ash in concrete (18.6 million tons by 2011). To extrapolate, we multiply each of the
incremental impacts calculated by the BEES model by 18.6 million.
b. We extrapolate the incremental impacts (i.e., impacts associated with use of 1 ton fly ash) to estimate the impacts of
current beneficial use of fly ash in concrete (15.0 million tons). The current quantity of fly ash that is beneficially used as a
substitute for finished portland cement in concrete is reported by ACAA's 2005 CCP Survey. We multiply each of the
incremental impacts calculated by BEES by 15.0 million tons to extrapolate these impacts to reflect current use.
c. We extrapolate the incremental impacts (i.e., impacts associated with use of 1 ton FGD gypsum) to estimate the impacts of
current beneficial use of FGD gypsum in wallboard (8.2 million tons). The current quantity of FGD gypsum that is beneficially
used as a substitute for finished portland cement in concrete is reported by ACAA's 2005 CCP Survey. We multiply each of
the incremental impacts calculated by SimaPro by 8.2 million to extrapolate these impacts to reflect current use.
Calculated as the sum of the fly ash and FGD gypsum current use extrapolations.
Nonrenewable energy refers to energy derived from fossil fuels such as coal, natural gas and oil.
Renewable energy refers to energy derived from renewable sources, but BEES does not specify what sources these include.
In addition to reporting energy impacts in megajoules (MJ), we monetize impacts by multiplying model outputs in MJ by the
average cost of electricity in 2006 ($0.0275/MJ), converted to 2007 dollars ($0.0280/MJ). The 2006 cost of energy is taken
from the Federal Register, February 27, 2006, accessed at: http://www.npga.org/14a/pages/index.cfm?pageid=914. The
cost was converted to 2007 dollars using NASA's Gross Domestic Product Deflator Inflation Calculator, accessed at:
http://cost.isc.nasa.gov/inflateGDP.html.
In addition to reporting water impacts in gallons, we monetize impacts by converting model outputs from liters to gallons
and multiplying by the average cost per gallon of water between July 2004 and July 2005 ($0.0023/gal), converted to 2007
dollars ($0.0024/gal). The 2005 cost of water is taken from NUS Consulting Group, accessed at:
https://www.energyvortex.com/files/NUS_quick_click.pdf. The cost was converted to 2007 dollars using NASA's Gross
Domestic Product Deflator Inflation Calculator, accessed at: http://cost.isc.nasa.gov/inflateGDP.html.
Greenhouse gas emissions have been converted to tons of C02 equivalent using U.S. Climate Technology Cooperation
Gateway's Greenhouse Gas Equivalencies Calculator accessed at: http://www.usctcgateway.net/tool/. This calculation only
includes C02 and methane.
Impacts in MTCE are calculated by dividing the impacts in AATC02E by 44/12 (the ratio of the molecular weight of carbon
dioxide to carbon). U.S. EPA, "A Climate Change Glossary," accessed at: http://www.globalwarming.org/node/91.
BEES reports waste as "end of life waste." In contrast, SimaPro reports "solid waste." In is not clear if these waste metrics
are directly comparable as SimaPro does not specify whether "solid waste" refers to manufacturing waste, end-of-life waste,
or both.
The results show that current beneficial use of fly ash in concrete and FGD gypsum in wallboard results
in positive environmental impacts. The most significant impacts include energy savings and water use
reductions. Energy savings associated with the use of fly ash and FGD gypsum totals approximately 167
5-7
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billion megajoules of energy (or approximately $4.7 billion in 2007 energy prices). Based on the average
monthly consumption of residential electricity customers, this is enough energy to power over 4 million
homes for an entire year. Avoided water use totals approximately 121 billion liters or approximately
$76.9 million in 2007 water prices).62 This is roughly equivalent to the annual water consumption of
61,000 Americans.63 The extrapolated beneficial impacts also include key impacts such avoided
greenhouse gas (11.5 million tons of avoided CO2 equivalent), and avoided air emissions (30.3 million
kilograms of avoided NOx, and 23.9 million kilograms of SOx). Note that the impacts presented in
Exhibit 5-3 represent only a partial estimate of the total impacts of beneficially using CCPs. Beneficial
use of fly ash as a substitute for finished portland cement in concrete and FGD gypsum in wallboard
accounts for only 47% (23.2 million tons) of all beneficially used CCPs in 2005,64
Economic Distribution of CCP Beneficial Use Impacts
In addition to an estimate of overall beneficial impacts associated with use of CCPs, we developed a
screening analysis using the EIO-LCA model to provide insight into the distribution of impacts across
economic sectors. We modeled the impacts associated with a hypothetical reduction of $1 million of
demand from the cement manufacture and gypsum mining sectors. From the perspective of energy and air
emissions, cement manufacturing leads to large impacts, and is in general the largest source of emissions
across the supply chain. Reducing the amount of cement produced by beneficially reusing products can
lead to large supply chain-wide reductions of emissions. Comparatively, the impact of the substitution of
FGD gypsum for virgin gypsum in wallboard manufacturing is less clear, as the EIO-LCA model was not
able to adequately represent the wallboard sector.
These results and others produced by the model do not affect the total estimate of beneficial impacts
associated with changes in use of CCPs. However, they indicate the specific sectors, activities, and points
in the supply chain that may be most important to consider in more detailed analyses of beneficial use
scenarios. The EIO-LCA model may provide important insights into the success of policies and actions,
because the model identifies the types of market changes that may result from specific changes in
practice. EIO-LCA may, therefore, clarify the positive and negative impacts of specific, targeted
programs and actions on different economic sectors. Appendix C provides a detailed discussion of the
analysis.
CONCLUSIONS AND NEXT STEPS
This report provides a preliminary assessment of the baseline impacts associated with the beneficial use
of fly ash and FGD gypsum in 2005. The analysis uses the life cycle-based BEES and SimaPro models,
coupled with simple monetized estimates of energy and water savings, to estimate the impacts of
replacing portland cement with fly ash in concrete and virgin gypsum with FGD gypsum in wallboard.
The most significant impacts include energy savings and water use reductions. Energy savings associated
with the use of fly ash and FGD gypsum totals approximately 167 billion megajoules of energy (or
approximately $4.7 billion in 2007 energy prices). Based on the average monthly consumption of
residential electricity customers, this is enough energy to power over 4 million homes for an entire year.
Avoided water use totals approximately 121 billion liters or approximately $76.9 million in 2007 water
62 Based on the assumption that an average residential customer uses 938 kilowatt-hours per month. Department of Energy, Energy Information
Administration, "Energy Basics 101," http://www.eia.doe.gov/basics/energybasics101.html. accessed August 30, 2007.
63 Based on 2000 USGS per capita water use estimate of 1,430 gallons per day. Lumia et al., United States Department of the Interior, United
States Geological Survey, Summary of Water Use in the United States, 2000.
64 As shown in Exhibit 4, a total of 49.6 million tons of CCPs were beneficially used in 2005.
5-8
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prices).65 This is roughly equivalent to the annual water consumption of 61,000 Americans.66 The
extrapolated beneficial impacts also include key impacts such avoided greenhouse gas (11.5 million tons
of avoided CO2 equivalent), and avoided air emissions (30.3 million kilograms of avoided NOx, and 23.9
million kilograms of SOx).
This report also presents a distributional screening analysis using the EIO-LCA model that indicates
significant avoided environmental impacts from reductions in the demand for cement or virgin gypsum
that are distributed across several economic sectors. From the perspective of energy and air emissions,
cement manufacturing leads to large impacts, and is in general the largest source of emissions across the
supply chain. Reducing the amount of cement produced by beneficially reusing products can lead to large
supply chain-wide reductions of emissions. Comparatively, the impact of the substitution of FGD
gypsum for virgin gypsum in wallboard manufacturing is less clear.
The preliminary results of this initial analysis suggest that a more detailed evaluation of the beneficial use
of CCPs could build on these results to assist the Agency in a more specific evaluation of the
achievements of the RCC program. A more detailed analysis would require:
The development of realistic and effective beneficial use scenarios that incorporate more detailed
descriptions of markets, beneficial uses, and policies. Realistic scenarios should reflect key
market dynamics and limits such as distance to markets and virgin material prices, and be able to
assess the impacts of these dynamics on the growth potential for specific beneficial uses. For
example, the limiting transportation distance for the beneficial use of CCPs in road construction
may be far less then that of gypsum wallboard.
The development of a methodology to attribute beneficial use impacts to specific EPA/RCC
efforts and programs. A phased approach may be appropriate. Such an approach could initially
employ the simple operating assumption that all impacts result from Agency actions. This
assumption could then be refined to reflect specific Agency strategies, policies, and other efforts,
and link these, where possible, to specific changes in beneficial use practices and markets.
The expansion of the assessment to include additional CCPs and beneficial use applications. This
analysis only examines the beneficial impacts of substituting fly ash for finished portland cement
in concrete and substituting FGD gypsum for virgin gypsum in wallboard manufacturing. These
two processes represent less than 50% of the total beneficial use of CCPs. Additional high
volume applications that may be analyzed include: the use of fly ash as a raw feed in cement
clinker; the use of boiler slag as blasting grit; and the use of various CCPs in structural fill and
waste stabilization. In addition, the beneficial impacts of lower volume applications may be
examined in order to identify those that may have potentially high incremental impacts.
65 Based on the assumption that an average residential customer uses 938 kilowatt-hours per month. Department of Energy, Energy Information
Administration, "Energy Basics 101," http://www.eia.doe.gov/basics/energybasics101.html, accessed August 30, 2007.
66 Based on 2000 USGS per capita water use estimate of 1,430 gallons per day. Lumia et al., United States Department of the Interior, United
States Geological Survey, Summary of Water Use in the United States, 2000.
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Standards, and Practices Related to the Use of Coal Combustion Products: Final Report," January
2005, Accessed at: http://www.undeerc.org/carrc/Assets/TXStateReviewFinalReport.pdf
EPA. (U.S. Environmental Protection Agency). 1999. Report to Congress: Wastes from the Combustion
of Fossil Fuels. Vol. II. EPA-530-R-99-010, March 1999.
EPA. (U.S. Environmental Protection Agency). 2003. "Underground Storage Tanks (UST) Cleanup &
Resource Conservation & Recovery Act (RCRA) Subtitle C Program Benefits, Costs, & Impacts
(BCI) Assessments: An SAB Advisory." EPA-SAB-EC-ADV-03-001
EPA. (U.S. Environmental Protection Agency). 2005. Using Coal Ash in Highway Construction: A Guide
to Benefits and Impacts. EPA-530-K-05-002, April 2005.
EPA. (U.S. Environmental Protection Agency). 2006. "About C2P2." Accessed at:
http://www.epa.gov/epaoswer/osw/conserve/c2p2/about/about.htm.
EPA. (U.S. Environmental Protection Agency). 2006. "Boiler Slag." Accessed at:
http://www.epa.gov/epaoswer/osw/conserve/c2p2/about/about.htm.
EPA. (U.S. Environmental Protection Agency). 2006."Advisory on EPA's Superfund Benefits Analysis."
EPA-SAB-ADV-06-002.
Glenn, J., Goss, D. and J. Sager. Undated. "C2P2Partnership Innovation."
Hendrickson, Chris, Lester Lave, and H. Scott Matthews. 2006. Environmental Life Cycle Assessment of
Goods and Services, Resources for the Future: Washington, DC, 2006.
Hassett, David J., Debra F. Pflughoeft-Hassett, Dennis L. Laudal, and John H. Pavlish. 1999. Mercury
Release from Coal Combustion ByProducts to the Environment.
Lumia, Deborah, Kristin Linsey, and Nancy Barber, United States Department of the Interior, United
States Geological Survey, Summary of Water use in the United States, 2000.
Miller, Cheri . Gypsum Parameters. Presentation at WOCA Short Course: "Strategies for Development of
FGD Gypsum Resources."
Portland Cement Association. 2006. "FAQ: Cement Supply Shortage." Accessed at:
http://www.cement.org/pca/shortageQA.asp.
Price, Jason and Mark Ewen, Industrial Economics, Inc. Memorandum to Lyn Luben, EPA, "Impact of
CAIR and CAMR on the Quantity and Quality of Coal Combustion Fly Ash Generated by
Affected Facilities." December 1, 2006.
Stein, Antoinette. 2006. State of California Department of Health Services. Personal Communication,
June 2006.
Schwartz, Karen D. 2003. "The Outlook for CCPs," Electric Perspectives, July/August 2003.
U.S. Department of Energy, National Energy Technology Laboratory, "General Summary of State
Regulations," accessed at: http://www.netl.doe.gov/E&WR/cub/states/select_state.html.
R-2
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US EPA, "Characterization of Building-Related Construction and Demolition Debris in the United
States" and "Characterization of Road-related Construction and Demolition Debris in the United
States," 2005. (Note that these documents were preliminary at the time of this Report and were
undergoing review).
US EPA, "Draft National Priority Trends Report (1999-2003) Fall 2005," as reported in the NPEP GPRA
2008 database of TRI data from 1998-2003.
US EPA, "Municipal Solid Waste in the United States: 2003 Data Tables," Table 1, accessed on October
26, 2006 at: http://www.epa.gov/epaoswer/non-hw/muncpl/pubs/03data.pdf
USGS, "Mineral Commodities Summary 2004: Construction Sand and Gravel," accessed at:
http://minerals.usgs.gov/minerals/pubs/commodity/sand & gravel construction/sandgmvb04.pdf
USGS, "Mineral Commodities Summary 2005: Lime," accessed at:
http://minerals.usgs. gov/minerals/pubs/commodity/lime/lime_myb05 .pdf
USGS, "Mineral Commodities Summary 2006: Gypsum," accessed at:
http://minerals.usgs.gov/minerals/pubs/commoditv/gvpsum/gypsumcs06.pdf
USGS, "Mineral Commodities Summary 2006: Cement," accessed at:
http://minerals.usgs. gov/minerals/pubs/commoditv/cement/cemenmcs06 .pdf
We Energies 2007. Tom Jason. Personal Communication. November 2006.
Wisconsin Department of Natural Resources. 2006. Bizhan Sheikholeslami. November 2000
Western Region Ash Group, "Applications and Competing Materials, Coal Combustion Byproducts,"
accessed at: http://www.wrashg.org/compmat.htm.
R-3
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APPENDIX A I KEY BENEFICIAL USE APPLICATIONS FOR CCPS
-------
EXHIBIT A-1 KEY BENEFICIAL USE APPLICATIONS FOR CCPs (2005)
BENEFICIAL USE APPLICATION AND
INDUSTRY
Concrete
Cement additive
Flowable fill
Structural fill
Road base
Soil stabilizer
Mineral filler in asphalt
Snow and ice control
Blasting grit
Mine reclamation
Wallboard
Waste stabilization
Agricultural soil amendment
Manufactured aggregate
Miscellaneous/other
CCP Category Use Totals
CCP Utilization Rate
Sources:
FLY ASH
14,989,958
2,834,476
88,549
5,710,749
205,032
715,996
62,546
591
0
626,428
0
2,657,046
23,856
180,275
1,022,952
29,118,454
41%
BOTTOM
ASH
1,020,659
939,667
0
2,321,140
1,056,660
205,322
21,583
531,549
89,109
46,604
0
42,353
7,670
692,501
567,155
7,541,972
43%
FLUE GAS
DESULFUR-
IZATION
GYPSUM
328,752
397,743
0
0
0
0
0
0
0
0
8,178,079
0
361,644
0
2,147
9,268,365
77%
FLUE GAS
DESULFUR-
IZATION
OTHER WET
MATERIAL
0
782
0
0
0
0
0
0
0
245,471
0
0
3,312
0
436,619
689,184
4%
FLUE GAS
DESULFUR-
IZATION
DRY
MATERIAL
13,965
0
9,673
2,666
0
1,535
0
0
0
112,100
0
0
19,259
0
0
159,198
11%
BOILER
SLAG
0
42,566
0
175,144
300
0
56,709
15,401
1,544,298
31,540
0
0
0
0
24,851
1,890,809
97%
PRODUCT SUBSTITUTES
Cement, Silica fume, Furnace slag
Clay, Soil, Shale, Gypsum
Soil, Sand, Gravel, Cement
Sand, Gravel, Soil, Aggregate
Cement, Lime, Aggregate
Cement, Lime, Aggregate
Sand
Sand
Sand
Soil
Natural gypsum
Cement, Lime, Cement kiln dust
Liming agents
Sand, gravel, aggregate
1. American Coal Ash Association. "2005 Coal Combustion Product (CCP) Production and Use Survey," accessed at: http://www.acaa-
usa.org/PDF/2005_CCP_Production_and_Use_Figures_Released_by_ACAA.pdf.
2. Western Region Ash Group, "Applications and Competing Materials, Coal Combustion Byproducts," accessed at: http://www.wrashg.org/compmat.htm.
Note: Results from the 2006 CCP Production a
to 41% above) reported for 2005. This reflects
incorporation into the benefits analysis.
nd Use Survey conducted by the ACM indicate a total fly ash utilization rate of 44.78 percent, up from 40.95 percent (rounded
an ongoing upward trend in the CCP utilization rate over the past decade. The 2006 results were received too late for
A-1
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APPENDIX B | USE OF LIFE CYCLE ANALYSIS IN AN EVALUATION
OF ECONOMIC BENEFITS
-------
Life cycle assessment (LCA) inventory analyses of the type presented in this report deliver
incremental changes in physical inputs, outputs, and energy arising from management or
regulatory changes to an industrial production process. This discussion addresses the following
issues: how does LCA relate to economic analysis of benefits, and how are economic impacts
derived from changes in "physical inventory," such as energy use and alternative waste streams?
RELATIONSHIP BETWEEN LCA AND ECONOMIC ANALYSIS OF
BENEFITS
LCA is a performance assessment tool - a method to depict physical outcomes that can be used to
assess impacts and measure progress over time. And because LCA is a systems approach to
assessment, it offers significant improvement over less comprehensive techniques. However, in
economic terms, LCA is only one component of a true analysis of benefits - albeit a central
component.
Consider the architecture of an economic benefit assessment. At the "front end" lies a set of
economic drivers that determine technologies and practices employed by industry. These drivers
include raw material prices, other input costs (including transport), competitive factors,
regulation, technology, and taxes. EPA programs such as RCC work to facilitate changes in the
economic drivers of waste generation, handling, and disposal (e.g., a change in tipping fees,
tighter permit requirements on landfills, benefits to participation in beneficial use programs, etc.).
Changes in these economic drivers can be expected to lead to changes in the physical system of
production. In other words, the physical system and its outputs are properly thought of as the
end product of a set of economic incentives (prices) and constraints (technology).
LCA depicts production as a system of sometimes reinforcing, sometimes counteracting physical
outcomes. In particular, it allows the analyst to predict the incremental physical consequences of
a change in disposal practices, technology, or price incentives. Any change in the physical
system leads to a corresponding cascade of system changes - as inputs are substituted, exposure
pathways are changed, and technology adapts. LCA produces the net result of these various
changes and, thus, the true, incremental effect on physical outputs.67
Deriving an incremental physical effect from a complex system is difficult enough. As the
agency seeks performance measures to satisfy its GPRA and PART requirements, LCA is a
natural starting point. It demands systems thinking, properly views outcomes as changes to
baseline conditions, identifies tradeoffs, and yields concrete, measurable metrics. LCA can tell us
who and what will be affected by changes in industrial practice, and even where changes are
likely to occur.
However, while LCA is a fundamental building block of benefit assessment, LCA does not itself
yield the social benefits and costs of industrial change. To do that, we must apply economic
valuation techniques to the physical outputs of LCA analysis.
For example, the PaLATE model generates incremental effects on physical outputs arising from changes in roadway materials.
B-1
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Economic Assessment is desirable because we don't really care about physical outcomes, we care
about what those outcomes imply for human well-being. Another way of putting this is, how do
we compare the "apples" of one change to the "oranges" of another?68 Also, how do we compare
a given "small" physical gain in one waste to a "large" reduction in another. In physical terms,
we might be tempted to say that the large gain outweighs the small loss. Of course, small
physical changes can have large health and environmental consequences with large economic
ramifications (think of the effect of radiation or toxics on health).
To understand how energy and raw materials use and emissions of different kinds affect well-
being we must make a set of additional "translations." A physical change in lead concentrations
leads, via ecological and epidemiological processes, to changes in human exposure. Changes in
exposure lead to morbidity and mortality effects. Morbidity and mortality effects have social
benefits and costs.69 Those benefits and costs are the ultimate goal of our analysis. In another
example, the effect of water consumption on well-being depends upon the location, timing, and
quality of the water that is consumed. The value of that water depends on how it would
otherwise be used - for human consumption, industrial uses, habitat support, irrigation, etc. LCA
tells us little, if anything, about these relationships. Thus, LCA may tell us relatively little about
the actual welfare effects of changes in industrial process.
Unfortunately, the translation of physical changes into economic outcomes is costly, difficult, and
often controversial when applied to human health or environmental outcomes. As the report
notes earlier, "with the exception of water and energy savings for which current price data are
available, we do not calculate these benefits in dollar terms because monetizing involves complex
valuation procedures." Putting economic value on even a small set of physical impacts can be a
significant and expensive proposition.
Accordingly, LCA should be regarded, not only as a necessary ingredient, but also as a practical
alternative to real benefit assessment. While economic benefits are the ultimate performance
measure, businesses and governments routinely rely on simpler - though imperfect - proxies to
facilitate management and performance assessment. As proxies, LCA outputs are a legitimate
and defensible compromise.
INVENTORY CHANGES AND WELFARE: THE TRANSLATION OF LCA
OUTPUTS TO ECONOMIC IMPACTS
There are two basic steps that must be employed to translate LCA-generated inventories into
social benefits. The first is the translation of LCA inventories into "final economic goods." The
second is the valuation of those final goods.
Mapping LCA inventories into final economic goods
In general, changes in LCA physical inventories will generate a set of corresponding changes in
other physical conditions relevant to human well-being. Even before economic valuation occurs,
these follow-on physical implications must be assessed. For instance, to value changes in
>8 Hendrickson, Lave, and Matthews (2006) ("A typical [Life Cycle Inventory] of air pollution results in estimates of conventional,
hazardous, toxic, and greenhouse gas emissions to the air. Even focused on this small subset of environmental effects, it is unclear
how to make sense of the multiple outputs and further how to make a judgment as to tradeoffs or substitutions of pollutants among
alternative designs."), 29.
>9 Some in the LCA community refer to this as an LCA impact analysis, as opposed to the preceding LCA inventory analysis. Inventory
analyses are those most commonly referred to as LCA. See Graedel and Allenby (1995).
B-2
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mercury releases, it is important to know how increased or decreased mercury emissions interact
with exposure pathways to affect body burdens and human health. An LCA inventory does not
address this issue; an analysis of epidemiology and exposure is required. Similarly, hydrological
analysis is required to determine how a reduction in water usage translates into water availability
in different locations and at different times. Further, ecological analysis must be deployed to
answer questions such as "what is the effect of greater water availability on species and habitats?"
The point is that benefit assessment requires synthetic systems thinking of an order at least as
great as the original LCA analysis.70
The goal of these biophysical and epidemiological translations is to translate LCA inventory
results to outcomes with direct human impact - health effects or the availability of water in a
particular stream at a particular time.
In the human health realm, toxic wastes or air quality burdens must be evaluated in terms of fate,
transport, and deposition models. Human health models then translate depositions into human
health impacts via epidemiological analysis (e.g., dose-response relationships). EPA is relatively
sophisticated in its use of such models, owing to decades of experience with air quality regulation
and the analysis of economic effects arising from air quality-related health assessments.
In the ecological realm, these kinds of translations are underdeveloped. The agency is aware of
this - the conclusion has been drawn from several recent SAB reports.71 The analysis of
ecological benefits is clarified by drawing distinctions between ecosystem processes and
functions and the "final" outcomes of those processes (denoted here as "final ecosystem goods."
Ecosystem processes and functions are the biological, chemical, and physical interactions
associated with ecological features such as surface water flows, habitat types, and species
populations. These functions are the things described by biology, atmospheric science,
hydrology, and so on.
Final ecosystem goods arise from these components and functions but are different: they are the
aspects of the ecosystem that are directly valued by people. The benefits of nature include many
forms of recreation, aesthetic enjoyment, commercial and subsistence harvests, damage
avoidance, human health, and the intangible categories mentioned earlier. Final ecosystem goods
are the aspects of nature used by society in order to enjoy those benefits.
Part of the above definition is particularly important: namely, that ecosystem services are "final."
Final goods are the things people actually make choices about. For an angler, these end products
include a particular lake or stream and perhaps a particular species population in that water body.
The choices involved include which lake, what kind offish, what kind of boat (if any) and tackle
to use, and how much time spent getting to and from the site. Valuation is about choices (is one
thing better than another) and choices are the only thing economists can use to establish economic
value. Environmental benefit assessment places values on the things people and households make
actual choices about - the "final goods" of nature. It is very important to emphasize that many
70 For an example of a full social cost ft benefit analysis see Krupnick and Burtraw (1997).
71 For example, this conclusion has been drawn from several recent SAB reports, including EPA-SAB. 2003. "Underground Storage Tanks
(LIST) Cleanup 6t Resource Conservation 6t Recovery Act (RCRA) Subtitle C Program Benefits, Costs, 6t Impacts (BCI) Assessments: An
SAB Advisory." (EPA-SAB-EC-ADV-03-001) and "Advisory on EPA's Superfund Benefits Analysis." (EPA-SAB-ADV-06-002). In addition, the
SAB Committee on Valuing the Protection of Ecological Systems and Services is currently examining methods for addressing these
limitations.
B-3
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other aspects of nature are valuable, but not capable of being valued in an economic sense -
because they are not subject to social or individual choices.
Ecosystem production functions are the relationships that translate LCA inventory changes into
final ecosystem goods. One characteristic of these production functions is particularly worthy of
note: ecological production functions are dependent upon space and landscape. Location- and
scale-specificity are core characteristics of modern ecology. For example, the quality of a habitat
asset can be highly dependent on the quality and spatial configuration of surrounding land uses.
The ability of areas to serve as migratory pathways and forage areas typically depends on
landscape conditions over an area larger than habitats relied upon directly by the migratory
species. The contiguity of natural land cover patches has been shown for many species to be an
indicator of habitat quality and potential species resilience. Hydrological analysis is yet another
field that has long recognized the importance of relationships between landscape features. The
nature of surface water flows, aquifer structures, and surface-groundwater interactions are
dependent upon linked physical relationships across the landscape.
For OSW to move toward measurement of ecosystem impacts arising from beneficial use, or any
other change in waste management practices, the ability to translate LCA inventory changes into
final ecosystem good changes requires the development of spatial ecological modeling. Space
and scale are important to the valuation of final ecosystem goods, as well.
Assigning value to changes in final ecological goods
The value of an ecosystem good is typically location-dependent. The value of a car is not closely
related to whether it is located in California or New Jersey. This is not the case with ecological
goods. The benefits of damage mitigation, aesthetic enjoyment, and recreational and health
improvements depend on whereand whenecosystem services arise relative to complementary
inputs and substitutes. Also, the ecological asset interactions that enhance or degrade service
flows are highly landscape-dependent. Accordingly, it is necessary to spatially define "service
areas." An unfortunate reality is that these will be different for every identified ecosystem service.
Boundaries are needed to define the likely users of a service, areas in which access to a service is
possible, and the area over which services might be scarce or have substitutes. This issue is well
known in environmental economics (Smith and Kopp 1996). For example, a key methodological
issue in any econometric recreational benefits study is the determination of the appropriate choice
set facing recreators.
While market prices can be assumed to be largely constant within a single market, there is no
arbitrage to ensure this condition for the implicit prices of environmental resources. Also, many
ecological services are best thought of as differentiated goods with important place-based quality
differences. As noted earlier, the biophysical characteristics of ecosystems are highly landscape-
dependent. The same is true of ecological services' social benefits. Accordingly, willingness to
pay for ecological services is best represented by a hedonic price function, not a single price.
An intermediate step: benefit indicators as an alternative to full
valuation
The spatial factors that affect ecosystem goods' value create a problem for analysts. Benefit
estimates from one study in one location cannot be transferred to other sites. In practical terms,
this means that ecosystem valuation is expensive, time-consuming, and difficult. Problem-
specific valuation will be impractical for most regulatory applications.
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In this context, one alternative to full-scale valuation is the use of "benefit indicators" (Boyd
2004, Boyd and Wainger 2002). The benefits of a given ecosystem good are affected by the
following: the ecosystem feature's scarcity, natural and built substitutes, complementary inputs,
and the number of people in proximity to it. All of these can and should be measured spatially.
Benefit indicators are map-able, countable landscape features that affect the value of a particular
ecosystem good. Benefit indicators are an input to a wide variety of tradeoff analysis approaches,
but do not themselves make or calculate the results of such tradeoffs. First, they can be used as
ends in themselves as regulatory or planning performance measures. Second, they can be used as
part of public processes designed to elicit public preferences over environmental and economic
options - as in mediated modeling exercises or more informal political derivations. Benefit
indicators are a potentially powerful complement to group decision processes. Third, they can be
used as inputs to economic and econometric methods such as benefit transfer, or stated preference
models. In the former, they can be used to calibrate the transfer function. In the latter case, they
can be used to develop alternative choice scenarios.
REFERENCES
Boyd, James, "What's Nature Worth? Using Indicators to Open the Black Box of Ecological
Valuation," Resources, 2004.
Boyd, James and Lisa Wainger, "Landscape Indicators of Ecosystem Service Benefits,"
84 American Journal of Agricultural Economics, 2002.
Graedel, T.E., and B.R. Allenby, Industrial Ecology, Prentice Hall: Englewood Cliffs NJ, 1995.
Hendrickson, Chris, Lester Lave, and H. Scott Matthews, Environmental Life Cycle Assessment
of Goods and Services, Resources for the Future: Washington, DC, 2006.
Krupnick, Alan and Dallas Burtraw, "Social Costs of Electricity: Do the Numbers Add Up?"
Resources and Energy 18:4, 1997, 423-466.
Porter, Richard, The Economics of Waste, Resources for the Future: Washington, DC, 2002.
Portney, Paul, "The Price Is Right: Making Use of Life Cycle Analyses," Issues in Science and
Technology, 10: 2 Winter, 1993, 69-75.
Smith, V. Kerry, and Ray Kopp, Valuing Natural Assets: The Economics of Natural Resource
Damage Assessment, (Resources for the Future: Washington, DC, 1996.
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APPENDIX C | ANALYSIS OF BENEFITS USING ALTERNATE LIFE
CYCLE MODELS
-------
In the main body of this report, we present an analysis of the life cycle benefits of substituting fly
ash for finished portland cement in concrete using BEES. For comparative purposes, this
appendix illustrates the impacts associated with beneficial use of fly ash in concrete that can be
calculated using two additional life cycle tools: the WARM and EIO-LCA models.
WARM MODEL ANALYSIS
The Waste Reduction Model (WARM) was created by EPA to help solid waste planners and
organizations estimate greenhouse gas (GHG) emission reductions from several different waste
management practices.72 WARM calculates GHG emissions for baseline and alternative waste
management practices, including source reduction, recycling, combustion, composting, and
landfilling. The user can construct various scenarios by entering data on the amount of waste
handled by material type and by management practice. WARM then automatically applies
material-specific emissions factors for each management practice to calculate the GHG emissions
and energy savings of each scenario. The model evaluates energy use and GHG emissions in
three stages of the life cycle: (1) raw material acquisition, (2) manufacturing (fossil fuel energy
emissions), and (3) waste management (carbon dioxide emissions associated with compost, non-
biogenic carbon dioxide and nitrous oxide emissions from combustion, and methane emissions
from landfills). At each of these points, the study also considers transportation-related energy use
and GHG emissions.
The WARM model reports avoided lifecycle GHG emissions in either metric tons CO2 equivalent
(MTCO2E) or metric tons CO equivalent (MTCOE), as well as energy use in BTUs. In addition,
the model converts these outputs to equivalent metrics including the equivalent number of cars
removed from the road in one year, the equivalent number of avoided barrels of oil burned, and
the equivalent number of avoided gallons of gasoline consumed. Currently, the only CCP
available for analysis using WARM is fly ash. WARM calculates GHG emissions and energy use
associated with use of fly ash in concrete as an alternative to landfill disposal. We first use
WARM to estimate the incremental impacts associated with beneficial use of one ton of fly ash in
concrete, in comparison to disposing of that ton of fly ash in a landfill. Then, we extrapolate the
results to estimate benefits associated with attainment of the 2011 RCC goal of beneficially using
18.6 million tons of fly ash in concrete.73
Results
Exhibit C-l presents the results of the WARM model analysis for the beneficial use of fly ash.74
The WARM model estimates that one ton of fly ash beneficially used in concrete results in
avoidance of approximately 0.91 MTCO2E of GHG emissions and 5.29 million BTUs of energy
use. Extrapolating these outcomes to the 2011 RCC goal of beneficially using 18.6 million tons
of fly ash in concrete, results in savings of approximately 17 million MTCO2E. According to the
72 WARM can be accessed at http://vosemite.epa.gov/oar/globalwarming.nsf/WARM7openforni. Version 8 of the model was used for this
analysis. Available information indicate that Version 8 was last updated in August of 2006.
73 WARM allows the user to define key modeling assumptions, such as landfill gas recovery practices and transport distance to MSW
facilities. For landfill gas (LFG) control, we select the "National Average" setting, which calculates emissions based on the anticipated
proportion of landfills with LFG control in 2000. For transport distances, we use the default setting (20 miles).
74 It is important to note that the results reported by WARM for avoided greenhouse gas emissions and avoided energy use may not be
directly comparable to those reported by the BEES model or PALATE model due to differences in the methodologies (including life
cycle system boundaries) employed by each model.
C-1
-------
WARM model, this is equivalent to removing 3.7 million cars from the road. In addition,
attaining the 18.6 million ton fly ash goal results in 98,394 BTUs (103.8 megajoules) of avoided
energy use. This energy savings is equivalent to 17 million barrels of avoided oil consumption,
787 million gallons of avoided gasoline consumption, or a reduction in annual energy use by
approximately half a million households.
EXHIBIT C-1: WARM RESULTS: IMPACTS OF BENEFICIAL USE OF FLY ASH IN CONCRETE
IMPACT
INCREMENTAL IMPACT OF USING
1 TON OF FLY ASH
TOTAL IMPACTS OF MEETING RCC
GOAL (18,600,000 TONS)3
GHG EMISSIONS AVOIDED (MTC02E)
EQUIVALENT NUMBER OF PASSENGER
CARS REMOVED FROM ROADWAYS
AVOIDED ENERGY USE (BTUs) b
EQUIVALENT AVOIDED OIL CONSUMPTION
(BARRELS)
EQUIVALENT AVOIDED GASOLINE
CONSUMPTION (GALLONS)
EQUIVALENT AVOIDED HOUSEHOLDS'
ANNUAL ENERGY CONSUMPTION
(HOUSEHOLDS)
0.91
0.20
5.29 million
$135,424
0.9?
42.33
0.03
16.93 million
3.72 million
98,394 billion
$2,52 billion
16.93 million
787.34 million
0.56 million
Notes:
a. The total impacts of meeting RCC goal represent the difference between beneficially using 18.6 million tons of fly ash
in concrete in comparison to disposal in a landfill.
b. In addition to reporting energy avoided energy use in BTUs, by the average retail price of electricity for all
sectors in 2006 ($0.0874/KWh or $0.0256/1,000 Btu). (Source: Energy Information Administration, "Electric Power
Monthly - Average Retail Price of Electricity to Ultimate Customers: Total by End-Use Sector," accessed on
October 10, 2006 at: .)
Sources:
1. US EPA, Solid Waste Management and Greenhouse Gases, A Life cycle Assessment of Emissions and Sinks, 2nd Edition,
May 2002. (EPA530-R-02-006) (WARM Model)
2. US EPA, Background Document for Life cycle Greenhouse Gas Emission Factors for Fly Ash Used as a Cement
Replacement in Concrete, November 2003. (EPA530-R-03-016)
Limitations and Assumptions
Although the WARM analysis provides a useful example of the energy use and GHG emissions
benefits that can be achieved through the beneficial use of fly ash in concrete, it is important to
recognize some of the key limitations of the work to date:
Our analysis assumes a 20-mile transport distance from the point of collection to the
landfill or concrete facility. In reality, transport distances may be greater or less than 20
miles. Adjusting transport distance would effect both GHG emissions and energy use.
Emissions factors used in WARM reflect national averages. Our analysis may therefore
over or under estimate impacts for a specific region or location. In addition, we use a
C-2
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national average for landfill gas recovery that may also over or understate emissions for
a specific landfill.
WARM does not specifically calculate impacts on purchased energy. Purchased energy
impacts may be incorporated into the avoided energy use metric, but this is not clear.
WARM reports some environmental impacts in physical quantities (e.g., BTUs energy,
Ibs NOx, etc.), not in monetized dollar effects.
EIO-LCA ANALYSIS
The goal of this task was to do a preliminary assessment of what the baseline energy and air
pollution effects are for existing cement production, such that any reduction of this demand in
terms of beneficially used fly ash would lead to reduced impact.
To estimate baseline impacts of cement production, the Economic Input-Output Life Cycle
Assessment (EIO-LCA) model was used. EIO-LCA was developed at Carnegie Mellon and
provides the capacity to evaluate economic and environmental effects across the supply chain for
any of 491 industry sectors in the U.S. economy. EIO-LCA also can represent the supply chain
use of inputs and resulting environmental outputs across the supply chain by using publicly
available data sources from the U.S. government. By integrating economic data on the existing
flow of commerce between commodity sectors with environmental data on releases and material
flows generated by each sector, it is possible to estimate the additional environmental emissions
caused by an increase in production within a particular sector, accounting for the supply chain.
This approach can be used to avoid some of the system boundary limitations of process LCA by
drawing upon data for the entire economy. The EIO-LCA model includes a variety of such
impacts for the entire US economy. For a closer look at the model, visit http://www.eiolca.net/
on the Internet.
Currently, the EIO-LCA model is in active use. Since 2000, the model has registered over
900,000 uses (or over 15,000 per month). Of identifiable access sites, educational users are most
common, but there is substantial use by government agencies, non-profit organizations and
companies. A surprising number of foreign users exist, suggesting that international comparisons
are of considerable interest.
Cement Analysis
Specifically within EIO-LCA, industry "Sector #327310: Cement Manufacturing" was selected
for analysis in the model. This industry comprises establishments primarily engaged in
manufacturing portland, natural, masonry, pozzolanic, and other hydraulic cements. Cement
manufacturing establishments may calcine earths or mine, quarry, manufacture, or purchase lime.
Examples of activities in this sector:
Cement (e.g., hydraulic, masonry, portland, pozzolana) manufacturing
Cement clinker manufacturing
Natural (i.e., calcined earth) cement manufacturing
One million dollars of demand from the cement manufacturing sector was input into EIO-LCA,
resulting in the summary estimate of supply-chain wide economic impacts shown in Exhibit C-2.
EIO-LCA is a linear model, thus the estimates scale in a constant fashion ($2 million of
C-3
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production would lead to double the results listed below). However the main point of EIO-LCA
is for screening purposes, thus the specific dollar values are less relevant than the broad,
economy-wide boundary which is able to show where less obvious supply chain impacts might
exist. These are noted below.
EXHIBIT C-2: TOP SECTORS THAT SUPPORT CEMENT MANUFACTURING IN THE US
(ECONOMIC)
327310
221100
550000
221200
211000
420000
484000
327992
212310
212100
SECTOR
Total for all sectors
Cement manufacturing
Power generation and supply
Management of companies and enterprises
Natural gas distribution
Oil and gas extraction
Wholesale trade
Truck transportation
Ground or treated minerals and earths manufacturing
Stone mining and quarrying
Coal mining
TOTAL
ECONOMIC
$ MILLIONS
1.90
1.06
0.083
0.050
0.043
0.041
0.039
0.033
0.027
0.018
0.017
VALUE
ADDED
$ MILLIONS
0.992
0.543
0.052
0.035
0.014
0.017
0.026
0.016
0.017
0.010
0.008
DIRECT
ECONOMIC
%
77.9
99.6
86.0
65.3
89.5
2.49
50.6
62.4
86.6
82.7
48.8
As shown in the "Total Economic" column of Exhibit C-2, there are significant purchases of
electricity, oil and gas, etc. across the supply chain. This is due to the recognized significant fuel
and energy inputs needed to produce cement. Also visible in the top 10 economic purchases are
purchases from minerals, stone, and coal.
Exhibit C-2 also summarizes which of the purchases are "direct", i.e., those made directly by the
cement manufacturer. For example EIO-LCA estimates that 86% of the electricity purchases
across the entire supply chain are direct. That means that only 14% of total electricity purchases
of cement manufacturing in the supply chain come from all other sectors' (indirect) purchases of
electricity. This would include electricity bought by oil and gas production and distribution,
stone and coal mining, etc. Note that this amount of direct purchases (86 percent) is a very large
amount compared to the usual electricity direct purchases that come from other sectors.
EIO-LCA also displays estimates of emissions and energy use across the supply chain, as shown
in Exhibits C-3 and C-4. Exhibit C-3 summarizes emissions of conventional air pollutants, and is
sorted by sulfur dioxide (SO2) emissions. Most SO2 comes from cement manufacturing (and
about 15% from power generation). While not shown explicitly in Exhibit C-3, further use of
EIO-LCA shows that about 90% of nitrogen oxides and VOC emissions from cement
manufacturing come from the cement manufacturing itself, 70% of carbon monoxide from the
supply chain production of cement comes from cement manufacturing, followed by truck
transportation. Ninety percent of PM10 emissions come from cement. In short, cement
manufacturing itself is a very polluting process, and avoiding emissions from its manufacture can
have large social benefits.
C-4
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EXHIBIT C-3: AIR EMISSIONS OF TOP 10 SECTORS THAT SUPPORT CEMENT
MANUFACTURING IN THE US (SORTED BY SO2)
327310
221100
212310
211000
221200
483000
324110
213112
482000
484000
SECTOR
Total for all sectors
Cement manufacturing
Power generation and supply
Stone mining and quarrying
Oil and gas extraction
Natural gas distribution
Water transportation
Petroleum refineries
Support activities for oil and gas operations
Rail transportation
Truck transportation
S02
MT
27.3
22.4
4.44
0.209
0.040
0.027
0.024
0.018
0.016
0.015
0.011
CO
MT
20.4
14.6
0.219
0.391
0.068
0.001
0.017
0.010
0.013
0.032
3.58
NOX
MT
31.7
28.6
2.01
0.147
0.030
0.052
0.129
0.004
0.010
0.272
0.258
VOC
MT
23.6
22.4
0.019
0.074
0.046
0.183
0.124
0.014
0.004
0.013
0.266
LEAD
MT
0.005
0.005
0.000
0
0
0
0
0
0
0
0.000
PM10
MT
3.96
3.48
0.094
0.043
0.001
0.001
0.012
0.002
0.002
0.006
0.006
Exhibit C-4 summarizes supply chain wide use of energy and electricity for producing cement.
The cement sector consumes about 80% of total supply chain primary energy use (and almost
90% of electricity, as noted above). Other sectors consuming top but less significant amounts of
energy (in the form of fuels) are truck and pipeline transportation sectors and petroleum refining.
EXHIBIT C-4: TOP 10 SECTORS THAT USE ENERGY ACROSS THE SUPPLY CHAIN FROM
CEMENT MANUFACTURING (SORTED BY TOTAL ENERGY USE)
327310
221100
484000
486000
S00202
327992
324110
483000
482000
211000
SECTOR
Total for all sectors
Cement manufacturing
Power generation and supply
Truck transportation
Pipeline transportation
State and local government electric utilities
Ground or treated minerals and earths
manufacturing
Petroleum refineries
Water transportation
Rail transportation
Oil and gas extraction
TOTAL
TJ
68.4
55.1
9.70
0.363
0.321
0.283
0.238
0.203
0.164
0.149
0.144
ELEC
MKWH
1.96
1.80
0.001
0.001
0.007
0
0.015
0.004
0.000
0.000
0.015
In summary, from the perspective of energy and air emissions, cement manufacturing leads to
large impacts, and is in general the largest source of emissions across the supply chain. Reducing
the amount of cement produced through beneficial use of fly ash can lead to large supply chain-
wide reductions of emissions.
C-5
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Gypsum Analysis
Within EIO-LCA, the industry "Sector #212390: Other Nonmetallic Mineral Mining" was
selected for analysis. This industry is aggregated to include many products and processes (and
thus is less representative of a specific industry like wallboard manufacture than the sector
representing cement manufacturing above). This U.S. industry comprises establishments
primarily engaged in developing the mine site, mining and/or milling, or otherwise beneficiating
(i.e., preparing) natural potassium, sodium, or boron compounds, phosphate rock, fertilizer raw
materials, or nonmetallic minerals. There are many products of this industry, a few of which are
summarized below:
Borate, natural, mining and/or beneficiating
Phosphate rock mining and/or beneficiating
Gypsum mining and/or beneficiating
Peat grinding
To estimate baseline effects, $ 1 Million Dollars of demand from the "Other nonmetallic mineral
mining" sector was input into EIO-LCA, resulting in the summary estimate of supply-chain wide
economic impacts shown in Exhibit C-5. As shown in the "Total Economic" column of Exhibit
C-5, there are significant purchases of electricity, oil and gas, and construction machinery, etc.
across the supply chain. This is due to the recognized significant fuel and energy inputs needed
to produce nonmetallic minerals like gypsum.
EXHIBIT C-5: TOP SECTORS THAT SUPPORT NONMETALLIC MINERAL MINING - AS A PROXY
FOR GYPSUM MANUFACTURING - IN THE US (ECONOMIC)
212390
484000
550000
221100
211000
420000
324110
333120
533000
531000
SECTOR
Total for all sectors
Other nonmetallic mineral mining
Truck transportation
Management of companies and enterprises
Power generation and supply
Oil and gas extraction
Wholesale trade
Petroleum refineries
Construction machinery manufacturing
Lessors of nonfinancial intangible assets
Real estate
TOTAL
ECONOMIC
$ MILLIONS
1.98
1.08
0.068
0.067
0.055
0.054
0.042
0.035
0.031
0.019
0.018
DIRECT
ECONOMIC
%
76.3
99.4
73.3
65.9
79.2
34.4
39.5
59.0
86.8
24.4
17.7
Exhibit C-5 also summarizes which of the purchases are "direct," (i.e., those made directly by the
nonmetallic mineral company). For example EIO-LCA estimates that 80% of the electricity
purchases across the entire supply chain of nonmetallic minerals mining are direct. That means
that only 20% of total electricity purchases in the supply chain come from all other sectors'
(indirect) purchases of electricity, including well-known electricity intensive sectors like
C-6
-------
manufacturing. This would include electricity purchased by oil and gas production and
distribution, machinery manufacturing, etc. Note that this level of direct purchases (80 percent) is
very large compared to the usual electricity direct purchases that come from other sectors.
EIO-LCA also displays estimates of emissions and energy use across the supply chain, as shown
in Exhibits C-6 and C-7. Exhibit C-6 summarizes emissions of conventional air pollutants, and is
sorted by sulfur dioxide (SO2) emissions. Most (85 percent) of SO2 emitted across the supply
chain of nonmetallic minerals comes from power generation (less than five percent from the
mining of the nonmetallic minerals, an important note). While not shown explicitly in Exhibit C-
6, further sorting of EIO-LCA emissions data estimates that about 50% of nitrogen oxides come
from power generation, followed by emissions from truck and rail transport (less than ten percent
from nonmetallic mineral mining). About 40% of VOC emissions result from nonmetallic
minerals mining itself, 80% of carbon monoxide from truck transportation across the supply chain
with nonmetallic mineral mining representing less than one percent. About 40% of PMi0
emissions come from nonmetallic mineral mining (about 15% from power generation). In short,
nonmetallic mineral mining itself is a very polluting process, and avoiding emissions from its
manufacture can have large social benefits, but emissions from energy production and
transportation are in some cases even more important than this sector.
C-7
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EXHIBIT C-6: AIR EMISSIONS OF THE TOP 10 SECTORS THAT SUPPORT NONMETALLIC
MINERAL MINING IN THE US (SORTED BY SO2)
SECTOR
Total for all sectors
Power generation and supply
Other nonmetallic mineral mining
Oil and gas extraction
Stone mining and quarrying
Petroleum refineries
Other basic inorganic chemical manufacturing
Truck transportation
Support activities for oil and gas operations
Iron and steel mills
Rail transportation
S02
MT
3.47
2.94
0.151
0.053
0.043
0.040
0.033
0.022
0.021
0.021
0.016
CO
MT
9.41
0.145
0.051
0.089
0.080
0.023
0.004
7.39
0.018
0.176
0.034
NOX
MT
2.85
1.33
0.241
0.039
0.030
0.009
0.002
0.533
0.013
0.016
0.297
VOC
MT
1.72
0.013
0.656
0.060
0.015
0.032
0.002
0.550
0.006
0.010
0.014
LEAD
MT
0.000
0.000
0
0
0
0
0
0.000
0
0.000
0
PM10
MT
0.421
0.062
0.169
0.002
0.009
0.004
0.002
0.013
0.003
0.015
0.007
Exhibit C-7 summarizes supply chain wide use of energy and electricity for producing
nonmetallic minerals. The nonmetallic mineral mining sector consumes about 70% of total
supply chain primary energy (and almost 80% of electricity, as noted above). Other sectors
consuming high but less significant amounts of energy (in the form of fuels) are power
generation, truck and pipeline transportation sectors, and petroleum refining.
EXHIBIT C-7: TOP 10 SECTORS THAT USE ENERGY ACROSS THE SUPPLY CHAIN FROM
NONMETALLIC MINERAL MINING (SORTED BY TOTAL ENERGY USE)
SECTOR
Total for all sectors
Other nonmetallic mineral mining
Power generation and supply
Truck transportation
Petroleum refineries
Other basic inorganic chemical manufacturing
Pipeline transportation
Iron and steel mills
State and local government electric utilities
Oil and gas extraction
Rail transportation
TOTAL
TJ
33.2
22.6
6.42
0.750
0.451
0.370
0.342
0.229
0.225
0.189
0.163
ELEC
MKWH
1.59
1.40
0.000
0.002
0.008
0.033
0.008
0.011
0
0.019
0.000
Context: Concrete production and wallboard manufacturing
While the beneficial use studies focus on the substitution of waste products for virgin products,
and the estimates above identify the avoided energy, cost, and emissions of these substitutions, it
is important to put into context the effects of the beneficial use. In this section we briefly show
c-8
-------
EIO-LCA results for the broader picture of concrete manufacturing (where fly ash is used in place
of some cement) and wallboard manufacturing (where FGD gypsum is used in place of virgin
gypsum). We do this to see how important these raw materials (cement and gypsum) are in the
supply chain of producing these final products.
Exhibit C-8 shows the top ten sectors that contribute to air emissions, and Exhibit C-9 the top ten
sectors that consume energy, in the production of concrete (using $1 million as input into the
ready-mix concrete sector). Exhibit C-8 (sorted by SO2 emissions) demonstrates that in the
manufacture of concrete, the emissions from cement manufacturing account for the majority of
SO2, NOx, VOC, and PM10 emissions. CO emissions are dominated by truck transportation.
Similarly Exhibit C-9 shows that cement manufacture represents 40% of energy use, and almost
50% of electricity use. This implies that any reduction in the amount of cement needed has a large
benefit in the life cycle emissions and energy use of concrete. Thus, fly ash substitution even at
20% substitution rates is quite beneficial.
EXHIBIT C-8: AIR EMISSIONS OF TOP 10 SECTORS THAT SUPPORT CONCRETE
MANUFACTURING IN THE US (SORTED BY SO2)
SECTOR
Total for all sectors
Cement manufacturing
Power generation and supply
Stone mining and quarrying
Water transportation
Other basic inorganic chemical manufacturing
Truck transportation
Rail transportation
Oil and gas extraction
Petroleum refineries
Other miscellaneous chemical product
manufacturing
S02
MT
6.29
3.74
1.61
0.570
0.072
0.055
0.034
0.025
0.024
0.021
0.013
CO
MT
16.9
2.43
0.080
1.07
0.050
0.006
11.3
0.055
0.041
0.012
0.000
NOX
MT
7.90
4.78
0.728
0.401
0.382
0.004
0.814
0.475
0.018
0.005
0.015
VOC
MT
5.64
3.74
0.007
0.202
0.367
0.003
0.840
0.022
0.027
0.017
0.003
LEAD
MT
0.001
0.000
0.000
0
0
0
0.000
0
0
0
0
PM10
MT
1.03
0.582
0.034
0.118
0.035
0.003
0.020
0.011
0.000
0.002
0.001
EXHIBIT C-9: TOP 10 SECTORS THAT USE ENERGY ACROSS THE SUPPLY CHAIN FROM
CONCRETE MANUFACTURING (SORTED BY TOTAL ENERGY USE)
SECTOR
Total for all sectors
Cement manufacturing
Power generation and supply
Ready- mix concrete manufacturing
Truck transportation
Sand, gravel, clay, and refractory mining
TOTAL
TJ
21.6
9.20
3.52
3.12
1.15
0.747
ELEC
MKWH
0.655
0.301
0.000
0.080
0.004
0.062
C-9
-------
For gypsum in wallboard manufacturing, a similar method is used, but the sector used to model
wallboard (Sector #327420: Gypsum Product Manufacturing) is more aggregated than that used
to model concrete. This industry comprises establishments primarily engaged in manufacturing
gypsum products such as wallboard, plaster, plasterboard, molding, ornamental moldings,
statuary, and architectural plaster work. Gypsum product manufacturing establishments may
mine, quarry, or purchase gypsum. Examples of activities in this sector include:
Board, gypsum, manufacturing
Gypsum building products manufacturing
Gypsum products (e.g., block, board, plaster, lath, rock, tile) manufacturing
Joint compounds, gypsum based, manufacturing
Wallboard, gypsum, manufacturing
Despite the limitations in modeling wallboard as an exclusive product, Exhibits C-10 and C-l 1
show the results of the supply chain emissions and energy use from the gypsum product
manufacturing sector in EIO-LCA (as a proxy for gypsum wallboard manufacturing).
EXHIBIT C-10: SUPPLY CHAIN EMISSIONS FROM THE GYPSUM PRODUCT MANUFACTURING
SECTOR
SECTOR
Total for all sectors
Power generation and supply
Stone mining and quarrying
Cement manufacturing
Water transportation
Paper and paperboard mills
Truck transportation
Oil and gas extraction
Petroleum refineries
Rail transportation
Natural gas distribution
SO2
MT
3.44
2.22
0.508
0.284
0.071
0.060
0.039
0.036
0.025
0.019
0.019
CO
MT
18.1
0.109
0.951
0.185
0.049
0.406
12.7
0.061
0.014
0.041
0.000
NOX
MT
3.94
1.00
0.358
0.363
0.374
0.085
0.918
0.027
0.006
0.354
0.036
VOC
MT
5.23
0.010
0.180
0.284
0.360
0.033
0.947
0.041
0.020
0.017
0.129
LEAD
MT
0.000
0.000
0
0.000
0
0
0.000
0
0
0
0
PM10
MT
1.02
0.047
0.105
0.044
0.035
0.045
0.022
0.001
0.003
0.008
0.001
Exhibit C-10 summarizes the air emissions across the manufacturing supply chain for gypsum
products (sorted by SO2 emissions). Recall that gypsum was modeled by production of the
nonmetallic mineral mining sector (and this is the virgin product we would be replacing).
Nonmetallic mineral mining is not in the top ten emissions sources in any of the tracked
conventional air emissions for gypsum product manufacturing. Exhibit C-l 1 shows that the
nonmetallic mineral mining sector represents about five percent of total energy use of gypsum
products.
C-10
-------
EXHIBIT C-1 1: ENERGY USE FOR THE GYPSUM PRODUCT MANUFACTURING SECTOR
SECTOR
Total for all sectors
Gypsum product manufacturing
Power generation and supply
Paper and paperboard mills
Truck transportation
Other nonmetallic mineral mining
TOTAL
TJ
24.0
9.50
4.84
2.16
1.29
1.25
ELEC
MKWH
0.810
0.368
0.000
0.130
0.004
0.077
As compared to the results for concrete manufacturing sector above, this wallboard example is
less clear. The wallboard sector was approximated by a highly aggregated sector and is not an
accurate representation of wallboard manufacturing in our attempt to model gypsum substitution.
This sector seems to more generally depend on stone sectors for its inputs.
C-11
-------
APPENDIX D | DETAILS OF FLY ASH AND FGD GYPSUM LIFE
CYCLE ANALYSIS METHODOLOGIES
-------
BEES ANALYSIS OF FLY ASH IN CONCRETE
We calculate the unit impacts of using fly ash as a substitute for finished portland cement in
concrete as the difference in impacts between concrete made with 100% portland cement and
concrete made with 15% fly ash and 85% portland cement. Exhibits D-l and D-2 show the
lifecycle stages modeled by BEES in the production of concrete with and without blended
cement. These diagrams represent the baseline and beneficial use scenarios evaluated in the fly
ash analysis.
EXHIBIT D-1: CONCRETE WITHOUT BLENDED CEMENT FLOW-CHART (BASELINE SCENARIO)
RortSaricl
Production
EXHIBIT D-2: CONCRETE WITH BLENDED CEMENT FLOW-CHART (BENEFICIAL USE
SCENARIO)
Functional Unit
of Concrete with
Fly Ash or Slag
Portland
Cement
Production
Fly Ash, Slag
or Limestone
Production
Fine
Aggregate
Production
Coarse
Aggregate
Production
D-1
-------
It is important to note that in Exhibit D-2, BEES does not actually model the impacts of fly ash
"production" from coal combustion (i.e. BEES does not allocate electricity production impacts to fly ash).
BEES Life Cycle inventory Data
Exhibit D-3 presents the complete BEES lifecycle inventory data for a generic concrete beam made with
and without blended cement (i.e. fly ash). The data fields in Exhibit D-3 are defined as follows:
XPORT DIST: Transport distance of concrete beam to construction site.
FLOW: The environmental impact being reported.
UNIT: The unit in which the environmental flow is reported.
TOTAL: The total impact across all life cycle stages for all three components (i.e., the sum of
fields COMF1, COMP2 and COMP3).
COMF1: The total impact across all life cycle stages for Component 1. Component 1 is the main
component, which is a 1 cubic yard concrete beam.
COMP2: The total impact across all life cycle stages for Component 2. Component 2 refers to the
first installation component associated with the concrete beam, but BEES does not provide a
specific definition.
COMP3: The total impact across all life cycle stages for Component 3. Component 3 refers to the
second installation component associated with the concrete beam, but BEES does not provide a
specific definition.
RAW1: Impacts associated with raw materials extraction for Component 1.
RAW2: Impacts associated with raw materials extraction for Component 2.
RAW3: Impacts associated with raw materials extraction for Component 3.
MFG1: Impacts associated with manufacturing of Component 1.
MFG2: Impacts associated with manufacturing of Component 2.
MFG3: Impacts associated with manufacturing of Component 3.
XPORT 1: Impacts associated with transport of Component 1.
XPORT2: Impacts associated with transport of Component 2.
XPORT3: Impacts associated with transport of Component 3.
USE1: Impacts associated with use of the total product (all three components).
WASTE 1: Impacts associated with disposal of the total product (all three components).
D-2
-------
EXHIBIT D-3: BEES LIFE CYCLE INVENTORY DATA FOR CONCRETE BEAM WITHOUT BLENDED CEMENT
BEES Data file B1011A: Generic Concrete Beam, 100% Portland Cement (4KSI)
XPORT
DIST
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
FLOW
Water Used (total)
Concrete Beam
Installation component 1
Main component
Installation component 2
Component 4
Component 5
Component 6
(a) Carbon Dioxide (CO2, fos
(a) Carbon Tetrafluoride (CF
(a) Lead (Pb)
(a) Mercury (Hg)
(a) Methane (CH4)
(a) Nitrogen Oxides (NOx as
(a) Nitrous Oxide (N2O)
(a) Particulates (PM 10)
(a) Sulfur Oxides (SOx as SO
(s) Aluminum (Al)
(s) Arsenic (As)
(s) Cadmium (Cd)
(s) Carbon (C)
(s) Calcium (Ca)
(s) Chromium (Crlll.CrVI)
(s) Cobalt (Co)
UNIT
liter
Cu yd
kg
kg
kg
kg
kg
kg
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
TOTAL
1,702.10
1.00
65.77
1,817.58
28.57
0.00
0.00
0.00
266,110.00
0.00
0.43
0.01
297.63
1,299.12
7.10
0.01
608.93
0.00
0.00
0.00
0.00
0.00
0.00
0.00
COMP1
1,055.10
0.00
0.00
1,817.58
0.00
0.00
0.00
0.00
213,972.00
0.00
0.01
0.01
206.68
1,171.98
6.71
0.01
479.47
0.00
0.00
0.00
0.00
0.00
0.00
0.00
COMP2
570.94
0.00
65.77
0.00
0.00
0.00
0.00
0.00
50,991.90
0.00
0.42
0.00
88.66
118.58
0.28
0.00
125.58
0.00
0.00
0.00
0.00
0.00
0.00
0.00
COMP3
4.39
0.00
0.00
0.00
28.57
0.00
0.00
0.00
1,146.09
0.00
0.00
0.00
2.29
8.56
0.12
0.00
3.88
0.00
0.00
0.00
0.00
0.00
0.00
0.00
RAW1
1,011.14
0.00
0.00
0.00
0.00
0.00
0.00
0.00
207,804.00
0.00
0.01
0.01
202.58
1,096.00
5.95
0.01
471.71
0.00
0.00
0.00
0.00
0.00
0.00
0.00
RAW2
570.02
0.00
0.00
0.00
0.00
0.00
0.00
0.00
50,863.70
0.00
0.42
0.00
88.57
117.07
0.26
0.00
125.41
0.00
0.00
0.00
0.00
0.00
0.00
0.00
RAWS
4.25
0.00
0.00
0.00
0.00
0.00
0.00
0.00
815.22
0.00
0.00
0.00
1.55
4.87
0.08
0.00
2.64
0.00
0.00
0.00
0.00
0.00
0.00
0.00
MFG1
6.05
0.00
0.00
0.00
0.00
0.00
0.00
0.00
862.43
0.00
0.00
0.00
0.57
13.60
0.03
0.00
0.71
0.00
0.00
0.00
0.00
0.00
0.00
0.00
MFG2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
MFG3
0.07
0.00
0.00
0.00
0.00
0.00
0.00
0.00
319.85
0.00
0.00
0.00
0.73
3.56
0.04
0.00
1.23
0.00
0.00
0.00
0.00
0.00
0.00
0.00
XPORT1
37.91
0.00
0.00
0.00
0.00
0.00
0.00
0.00
5,305.62
0.00
0.00
0.00
3.52
62.38
0.73
0.00
7.06
0.00
0.00
0.00
0.00
0.00
0.00
0.00
XPORT2
0.92
0.00
0.00
0.00
0.00
0.00
0.00
0.00
128.19
0.00
0.00
0.00
0.09
1.51
0.02
0.00
0.17
0.00
0.00
0.00
0.00
0.00
0.00
0.00
XPORT3
0.08
0.00
0.00
0.00
0.00
0.00
0.00
0.00
11.02
0.00
0.00
0.00
0.01
0.13
0.00
0.00
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
USE1
71.67
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
WASTE1
71.67
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
D-3
-------
BEES Data file B1011A: Generic Concrete Beam, 100% Portland Cement (4KSI)
XPORT
DIST
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
FLOW
(s) Copper (Cu)
(s) Iron (Fe)
(s) Lead (Pb)
(s) Manganese (Mn)
(s) Mercury (Hg)
(s) Nickel (Ni)
(s) Nitrogen (N)
(s) Oils (unspecified)
(s) Phosphorus (P)
(s) Sulfur (S)
(s) Zinc (Zn)
(w) BODS (Biochemical Oxygen
(w) COD (Chemical Oxygen Dem
(w) Copper (Cu+, Cu++)
(w) Suspended Matter (unspec
Waste (end-of-Life)
E Total Primary Energy
UNIT
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
kg
MJ
TOTAL
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
15.80
82.36
0.08
43.64
1,883.35
2,779.14
COMP1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
7.04
59.57
0.00
31.97
0.00
1,994.61
COMP2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
7.47
20.40
0.08
9.85
0.00
658.19
COMP3
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.28
2.39
0.00
1.81
0.00
126.35
RAW1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
6.25
52.89
0.00
28.39
0.00
1,904.34
RAW2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
7.45
20.26
0.08
9.78
0.00
656.30
RAWS
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.28
2.37
0.00
1.80
0.00
121.11
MFG1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.11
0.92
0.00
0.49
0.00
12.42
MFG2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
MFG3
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.01
0.00
0.01
0.00
5.07
XPORT1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.68
5.76
0.00
3.09
0.00
77.86
XPORT2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.02
0.14
0.00
0.07
0.00
1.88
XPORT3
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.01
0.00
0.01
0.00
0.16
USE1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
WASTE1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1,883.35
0.00
D-4
-------
EXHIBIT D-4: BEES LIFE CYCLE INVENTORY DATA FOR CONCRETE BEAM WITHOUT BLENDED CEMENT
BEES Datafile B1011B: Generic Concrete Beam, 100% Portland Cement (4KSI)
XPORT
DIST
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
FLOW
Water Used (total)
Concrete Beam
Installation component 1
Main component
Installation component 2
Component 4
Component 5
Component 6
(a) Carbon Dioxide (CO2, fos
(a) Carbon Tetrafluoride (CF
(a) Lead (Pb)
(a) Mercury (Hg)
(a) Methane (CH4)
(a) Nitrogen Oxides (NOx as
(a) Nitrous Oxide (N2O)
(a) Particulates (PM 10)
(a) Sulfur Oxides (SOx as SO
(s) Aluminum (Al)
(s) Arsenic (As)
(s) Cadmium (Cd)
(s) Carbon (C)
(s) Calcium (Ca)
(s) Chromium (Cr III, CrVI)
(s) Cobalt (Co)
UNIT
liter
Cu yd
kg
kg
kg
kg
kg
kg
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
TOTAL
1,690.06
1.00
65.77
1,817.58
28.57
0.00
0.00
0.00
243,685.00
0.00
0.43
0.01
278.61
1,231.00
6.68
0.01
555.41
0.00
0.00
0.00
0.00
0.00
0.00
0.00
COMP1
1,043.05
0.00
0.00
1,817.58
0.00
0.00
0.00
0.00
191,547.00
0.00
0.01
0.01
187.66
1,103.86
6.28
0.01
425.95
0.00
0.00
0.00
0.00
0.00
0.00
0.00
COMP2
570.94
0.00
65.77
0.00
0.00
0.00
0.00
0.00
50,991.90
0.00
0.42
0.00
88.66
118.58
0.28
0.00
125.58
0.00
0.00
0.00
0.00
0.00
0.00
0.00
COMP3
4.39
0.00
0.00
0.00
28.57
0.00
0.00
0.00
1,146.09
0.00
0.00
0.00
2.29
8.56
0.12
0.00
3.88
0.00
0.00
0.00
0.00
0.00
0.00
0.00
RAW1
999.10
0.00
0.00
0.00
0.00
0.00
0.00
0.00
185,379.00
0.00
0.01
0.01
183.56
1,027.87
5.53
0.01
418.19
0.00
0.00
0.00
0.00
0.00
0.00
0.00
RAW2
570.02
0.00
0.00
0.00
0.00
0.00
0.00
0.00
50,863.70
0.00
0.42
0.00
88.57
117.07
0.26
0.00
125.41
0.00
0.00
0.00
0.00
0.00
0.00
0.00
RAWS
4.25
0.00
0.00
0.00
0.00
0.00
0.00
0.00
815.22
0.00
0.00
0.00
1.55
4.87
0.08
0.00
2.64
0.00
0.00
0.00
0.00
0.00
0.00
0.00
MFG1
6.05
0.00
0.00
0.00
0.00
0.00
0.00
0.00
862.43
0.00
0.00
0.00
0.57
13.60
0.03
0.00
0.71
0.00
0.00
0.00
0.00
0.00
0.00
0.00
MFG2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
MFG3
0.07
0.00
0.00
0.00
0.00
0.00
0.00
0.00
319.85
0.00
0.00
0.00
0.73
3.56
0.04
0.00
1.23
0.00
0.00
0.00
0.00
0.00
0.00
0.00
XPORT1
37.91
0.00
0.00
0.00
0.00
0.00
0.00
0.00
5,305.62
0.00
0.00
0.00
3.52
62.38
0.73
0.00
7.06
0.00
0.00
0.00
0.00
0.00
0.00
0.00
XPORT2
0.92
0.00
0.00
0.00
0.00
0.00
0.00
0.00
128.19
0.00
0.00
0.00
0.09
1.51
0.02
0.00
0.17
0.00
0.00
0.00
0.00
0.00
0.00
0.00
XPORT3
0.08
0.00
0.00
0.00
0.00
0.00
0.00
0.00
11.02
0.00
0.00
0.00
0.01
0.13
0.00
0.00
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
USE1
71.67
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
WASTE1
71.67
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
D-5
-------
BEES Datafile B1011B: Generic Concrete Beam, 100% Portland Cement (4KSI)
XPORT
DIST
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
FLOW
(s) Copper (Cu)
(s) Iron (Fe)
(s) Lead (Pb)
(s) Manganese (Mn)
(s) Mercury (Hg)
(s) Nickel (Ni)
(s) Nitrogen (N)
(s) Oils (unspecified)
(s) Phosphorus (P)
(s) Sulfur (S)
(s) Zinc (Zn)
(w) BODS (Biochemical Oxygen
(w) COD (Chemical Oxygen Dem
(w) Copper (Cu+, Cu++)
(w) Suspended Matter (unspec
Waste (end-of-Life)
E Total Primary Energy
UNIT
g
g
g
g
g
g
g
g
g
g
g
g
g
g
g
kg
MJ
TOTAL
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
15.69
81.45
0.08
43.14
1 ,883.35
2,629.00
COMP1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
6.93
58.66
0.00
31.48
0.00
1,844.47
COMP2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
7.47
20.40
0.08
9.85
0.00
658.19
COMP3
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.28
2.39
0.00
1.81
0.00
126.35
RAW1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
6.14
51.98
0.00
27.90
0.00
1,754.19
RAW2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
7.45
20.26
0.08
9.78
0.00
656.30
RAWS
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.28
2.37
0.00
1.80
0.00
121.11
MFG1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.11
0.92
0.00
0.49
0.00
12.42
MFG2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
MFG3
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.01
0.00
0.01
0.00
5.07
XPORT1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.68
5.76
0.00
3.09
0.00
77.86
XPORT2
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.02
0.14
0.00
0.07
0.00
1.88
XPORT3
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.01
0.00
0.01
0.00
0.16
USE1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
WASTE1
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1,883.35
0.00
D-6
-------
Calculation of Unit Impacts
To illustrate the methodology used to calculate the unit impact values from the BEES life cycle
inventory data, we present a sample calculation of CO2 reductions resulting from the substitution
of one ton of fly ash for finished portland cement in concrete (see Exhibit D-6).
EXHIBIT D-5: EXAMPLE CALCULATION OF IMPACT METRIC FOR WATER USAGE RELATED
TO FLY ASH SUBSTITUTION IN CONCRETE
CALCULATION
3 KSI CONCRETE
PAVEMENT
NOTE/SOURCES
IMPACTS PER CUBIC YARD CONCRETE
100% portland cement
15% coal fly ash
Incremental benefit
[a]
[b]
[c]=[a]-[b]
266,1 10 grams
per cubic yard
of concrete
243,685 grams
per cubic yard
of concrete
22,425 grams
per cubic yard
of concrete
Values represent impacts related to a 4 KSI
concrete beam as characterized in BEES data file
B1011A. BEES Version 3.0 Performance Data.
Values represent impacts related to building
products and pavement as characterized in BEES
data file B1011B. BEES Version 3.0 Performance
Data.
Represents avoided CO2, in grams per cubic yard
of concrete product substituting 15% coal fly ash
for portland cement.
IMPACTS PER U.S. SHORT TON FLY ASH
Ibs cement/yd3 concrete
Percent coal fly ash
substitution
Ibs/U.S. short ton
tons fly ash/yd3 concrete
unit impact
[d]
[e]
[f]
[g] = [d]*[e]/[f]
[h] = [c]/[g]
470 Ibs
cement/cubic
yard of concrete
15%
2000 Ibs/ton
0.0352 tons coal
fly ash /cubic
yard of concrete
636,170 grams
per ton of coal
fly ash
substituted for
cement
Represents proportion of one cubic yard of
concrete made up of cementitious material,
given a mix-design or constituent density
(Lipiatt, 2002, p. 40).
Fifteen percent of cementitious material is
replaced with coal fly ash.
Conversion factor for pounds to tons.
Conversion of quantity of coal fly ash in one
cubic yard of concrete from pounds to tons.
Represent unit impact values for CO2 (in grams),
based on substitution of one ton of coal fly ash
for 1 ton portland cement in concrete.
The process outlined in Exhibit D-6 is repeated for each of the environmental metrics evaluated
in this analysis using the environmental performance data reported in BEES. For each
environmental metric, this yields an estimate of the benefit of one ton of fly ash replacing
finished portland cement in concrete.
D-7
-------
SIMAPRO ANALYSIS OF FGD GYPSUM IN WALLBOARD
We calculate the unit impacts of using FGD gypsum in place of virgin gypsum stucco in
wallboard as the difference in impacts between wallboard made with 100% virgin gypsum and
wallboard made with 100% FGD gypsum. Exhibits D-6 and D-7 show the lifecycle stages in the
production of wallboard with 100% virgin gypsum and 100% FGD gypsum, respectively. The
boxes with dashed lines represent life cycle stages that are unique to virgin or FGD gypsum.
EXHIBIT D-6: VIRGIN GYPSUM WALLBOARD MANUFACTURE
Wallboard
I I
; Stucco Manufacture i
t
Material Transport
! Gvpsum Mining j
Paper
EXHIBIT D-7: FGD GYPSUM WALLBOARD MANUFACTURE
Wallboard
Material Transport
1
.1
Dewatering
.1.
Flu Gas
Desulphurization
Paper
D-8
-------
As shown in Exhibits D-6 and D-7, by replacing virgin gypsum stucco with FGD gypsum,
gypsum mining and stucco manufacture can be avoided but a dewatering step is added to the
lifecycle. We model these impacts as one ton of avoided "stucco" manufacture in SimaPro.75
Stucco is the term used in SimaPro to describe the gypsum material used in wallboard. We
selected the Ecolnvent data set because it includes gypsum mining but also includes the
processing of gypsum for use in wallboard (i.e., burning of gypsum and milling of stucco for use
in gypsum wallboard). Thus, this dataset includes all the processes that would be avoided if an
equivalent quantity of FGD gypsum were used in place of stucco in wallboard. The production of
FGD gypsum through the coal combustion process is not modeled, as discussed in Chapter 4. In
addition, this analysis assumes that FGD gypsum dewatering occurs via holding ponds and that
the environmental impacts are negligible.76 This analysis also does not model transport distance;
we assume FGD gypsum would have the same transport distances to the construction site as
virgin gypsum.77 Thus avoided gypsum mining and avoided processing of gypsum into stucco, as
represented by the Ecolnvent stucco manufacturing data set, are the only lifecycle stages modeled
in SimaPro.
Exhibit D-8 presents the assumed life cycle system boundaries for the Ecolnvent stucco
manufacturing data set. The cut-off node for the process flow tree depicted in Exhibit D-8 is set to
0.5% so that the entire tree could be viewed. Thus, this process tree lists the flows associated with
99.5% of the total life cycle impacts for one ton of stucco manufacture.78 The numbers that
appear in the bottom left-hand corner of each box in the tree are partition factors used by SimaPro
and are not central to this analysis.
The Ecolnvent dataset for stucco manufacture is the only stucco dataset available in SimaPro, but
because it reflects Swiss manufacturing processes and electricity mix, we modified the data for
stucco manufacture to reflect the average U.S. electricity mix. We made this modification by
substituting the electricity used to make stucco from gypsum, as well as the electricity used
further down the production chain in gypsum mining, with the Franklin data set for average U.S.
electricity mix titled "Electricity avg. kWh USA". The Franklin data set includes the fuel
consumption associated with the generation and delivery of an average kilowatt-hour in the USA
using average USA technology in the late 1990's. While we did not substitute the U.S. electricity
mix at points further down the stucco production chain, the stucco manufacturing and gypsum
mining processes account for the majority of electricity use in this analysis.79
75 We use the Ecolnvent data set titled "Stucco, at plant/CH U" for this purpose.
76 There may actually be emissions/dusting impacts associated with dewatering in a holding pond, but we have been unable to identify
quantified estimates of these impacts. Alternatively, dewatering may be accomplished through mechanical processes but we were also
unable to identify the energy impacts of mechanical dewatering.
77 We do not model a transport differential between virgin and FGD gypsum to be consistent with the transport assumptions used in the
BEES fly ash analysis, which helps preserve the comparability of the fly ash and FGD gypsum unit impact values. It is important to note,
however, that an increasing number of new gypsum wallboard plants are being constructed adjacent to coal-fired power plants, so
transport distance of FGD gypsum to the wallboard manufacturing facility may, in some cases, be less than the transport distance of
virgin gypsum.
78 The tree is presented for the "single score" of all life cycle impacts, calculated using the Eco-lndicator 99-H, v2.04 impact assessment
method.
79 One limitation of substituting the Franklin U.S. electricity data set is that it represents low-voltage electricity production, but was
used in place of medium-voltage European electricity production. This has the effect of slightly overstating the environmental impacts
associated with electricity production in this analysis. Franklin U.S. electricity data set is the only data set in lEc's version of SimaPro
for average U.S. electricity production; a data set for medium-voltage U.S. electricity production is not available.
D-9
-------
EXHIBIT D-8: LIFE CYCLE SYSTEM BOUNDARIES FOR STUCCO MANUFACTURE, 0.5% CUT-OFF
I,16E9kg nl
Sypsum, mineral, at
mine/CHU(U.S, U
Energy mix) I
S.66E6 ||
1
[ |
1.01E8MJ
Electricity avg, kWh
USA
9.39E5
1
9,17E4kg 12,9m
Blasting/RER U Conveyor belt, at
plant/RER/I U
1.2C5 1.72E3
i,15E3kg
Synthetic rubber,
at plant/RER U
378
2.23E7MJ 6,93E6kg
Diesel, burned in Coal into electricity
building boilers
machine GLO U
2.2C5 5.Q4ES
f
6.76E5rn3
Nat, gas into electr.
boilers
1.6SE5
6,4E5ko 7,32E6kg
Diesel, at regional Coal FAL
storage RER U
3.22E5 _ 1.16E5
423kg
Carbon black, at
plant GLO U
146
Crude
produ
onshore
3.86E4
5kg
oi, at
ction
RMEU
t
6.63E5 kg
Diesel, at
refinery RER U
,25E5
6.51E
Wat. ga
industr,
1.59E5
1 .33E6 rn3
Natural gas FAL
2.37E5
l,02E6m3
Natural gas,
production DE, at
long-distance
1.4E5
3,26E6rn
Natura ga
production DZ
long-distan
4.74E5
l.lE6m3
Natural gas, at
production
onshore/DE U
1 .46E5
at
3.6E6m3
Natural gas, at
production
onshore/DZ U
4.63E5
s into
boilers
lE9kg
Stucco, atplant/CHH
U (U.S. energy mix)!
,2E7 I
I '
I
7.01E8MJ
Heat, natural gas,
at industria furnace
>100kW/RERU
3.21E6
| 1
7.33ESMJ HI
Natural gas, burned
n industr al furnace
>100kW/RERU M
3.22E6 H
1.37E6m3
Natural gas,
production DZ, at
evaporation
2.16E5
i.37E6m3
Natural gas,
liquefied, at freight
ship/DZ U
2.11E5
I.37E6m3
Natural gas,
liquefied, at
liquefaction
2, OSES
7.4ESMJ
Natural gas, high
pressure, at
consumer /RER U
2.93E6
1 '
2,03E7m3
Natural gas, at
long-distance
pipeline/RER U
2.92E6
TT
H
3,l!E5m3
Natural gas,
production GE, at
long-distance
,07E5
8. !E5m3
production
offshore/GB U
1.06E5
4.39E6 m3
Natural gas,
production NL, at
long-distance
6.24ES
1
1.46E6m3 3.5E6 m3
Natural gas, at Natural gas, at
production production
offshore/NL U onshore/NL U
1.85E5 _ 4.37E5
J
.7SEB MJ
Heat, heavy fuel
oil, at industrial
furnace 1MW/CHU
1.17E6
I.84E8MJ
Heavy fuel oil,
burned in industria
furnace IMW,
1.17E6
4,53E6kg
Heavy fuel oil, at
regional storage/CH
U
3.42E5
Heavy fuel oil, at
refnery/CHU
8.26E5
1
3.46E6m3 6,91E6m3
Natural gas, Natural gas,
production NO, at production RU, at
long-distance long-distance
4.58E5 . 1.12E6 |
] 1
3.&6E6 m3 8.09E6 m3 3.32E"1 ttm
Natural gas, at Natural gas, at Transport, natural
production production gas, pipehni- jnq
offshore NO U onshore/RU U distance/RU U
4.67E5 . 1.07E& 2.06E5
3,71E6kg
Crude oil,
production NG, at
long distance
3.27E5
2.57E6 kg
Crude oil,
production RAF, at
long distance
4.39E5 .
l,77E6kg
Crude oi , at
production/NG LI
3.23E5
2.66E6 kg
Crude oil, at
production
onshore RAF U
4.48E5
I 1 ^
3.91E7MJ
Natural gas, burned
in gas turbine, for
compressor
1.76E5
.51E7M]
Natura gas, sweet,
burned in
production
7.28E4
D-10
-------
SimaPro Life Cycle Inventory Data
Exhibit D-9 presents the SimaPro lifecycle inventory data for stucco manufacture for the same metrics
evaluated in the BEES analysis.
In order to easily compare the results of the FGD gypsum analysis with those of the fly ash analysis, it
was necessary to convert the environmental metrics reported by SimaPro into the same units that are
reported by BEES. For most metrics, this required only a simple conversion between different units of
mass. In the case of energy use, however, SimaPro reports quantities of various fossil fuels consumed
whereas BEES reports energy consumed in megajoules. To convert the fossil fuel quantities reported by
SimaPro into equivalent energy content in megajoules, we relied on the Energy Information
Administration's Coal, Natural Gas, and Crude Oil Conversion Calculators.80
In addition, SimaPro does not report a single "water use" metric, as is done in BEES, but breaks out fresh
water use by origin (e.g., lake, river, well, etc.) and application (cooling, turbine, etc). We sum the
following metrics (converted to liters) to obtain the water use figure in the FGD gypsum analysis: 1)
Water, cooling, unspecified natural origin/m3, 2) Water, lake, 3) Water, river, 4) Water, turbine use,
unspecified natural origin, 5) Water, unspecified natural origin/m3, and 6) Water, well, in ground.
Accessed at: http://www.eia.doe.gov/kids/energvfacts/science/energy calculator. html#coalcalc.
D-11
-------
EXHIBIT D-9: SIMAPRO LCI DATA FOR ONE TON STUCCO, AT PLANT
SUBSTANCE
Gypsum, in ground
Total Energy
Non-Renewable Energy
Coal, 26.4 MJ per kg, in ground
Coal, brown, in ground
Coal, hard, unspecified, in ground
Gas, natural, 46.8 MJ per kg, in
ground
Gas, natural, in ground
Oil, crude, 42 MJ per kg, in ground
Oil, crude, in ground
Renewable Energy
Energy, from hydro power
Energy, gross calorific value, in
biomass
Energy, kinetic, flow, in wind
Energy, potential, stock, in barrage
water
Energy, solar
Fresh Water Use
Water, cooling, unspecified natural
origin/m3
COMPARTMENT
Raw
Raw
Raw
Raw
Raw
Raw
Raw
Raw
Raw
Raw
Raw
Raw
Raw
Raw
UNIT
tn.lg
kg
g
g
kg
m3
g
kg
MJ
kJ
kJ
MJ
kJ
dm3
STUCCO, AT
PLANT/CH U (U.S.
ENERGY MIX)
1 .046899978
6.756131931
315.4661176
412.5766501
1.156160311
20.95771832
268.9543393
4.981418424
9.697825819
454.7219368
235.1774187
3.294986059
3.740125096
58.63469673
CONVERTED TO BEES
UNITS
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
MJ
liter
liter
12,582.66
12,568.97
178.36
7.61
9.96
54.11
799.32
11,296.08
223.53
13.69
9.70
0.45
0.24
3.29
0.00
14,214.60
58.63
NOTES
'converted using the ElA's Energy Calculator3
'converted using the ElA's Energy Calculator3
'converted using the ElA's Energy Calculator3
'converted using the ElA's Energy Calculator3
D-12
-------
SUBSTANCE
Water, lake
Water, river
Water, turbine use, unspecified
natural origin
Water, unspecified natural
origin/m3
Water, well, in ground
Carbon dioxide, biogenic
Carbon dioxide, fossil
Carbon Monoxide
Carbon monoxide
Carbon monoxide, fossil
Lead
Mercury
Methane
Methane
Methane, fossil
Nitrogen oxides
Ozone
Particulates < PM10
Particulates, < 10 um
Particulates, < 2.5 um
Particulates, > 2.5 um, and < 10um
Particulates, > 10 um
Particulates, unspecified
COMPARTMENT
Raw
Raw
Raw
Raw
Raw
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
Air
UNIT
cm3
cu.in
m3
dm3
cu.in
g
kg
g
g
mg
Mg
g
g
g
mg
g
g
g
kg
g
STUCCO, AT
PLANT/CH U (U.S.
ENERGY MIX)
149.6500813
704.9737212
14.11964941
22.25850268
143.8279244
39.8286174
77.7542381 1
9.12143624
29.9384285
28.76417316
976.1346395
39.14177696
136.3669305
168.024936
11.45337237
3.45821205
90.43917261
427.0304396
1.194254106
17.10845282
CONVERTED TO BEES
UNITS
liter
liter
liter
liter
liter
g
g
g
g
g
g
g
g
g
g
0.15
11.55
14,119.65
22.26
2.36
77,754.24
39.059865
0.03
0.00
175.51
168.02
0.0114534
520.9278
1,194.25
17.11
NOTES
D-13
-------
SUBSTANCE
Sulfur oxides
BODS, Biological Oxygen Demand
COD, Chemical Oxygen Demand
Copper, ion
Lead
Mercury
Suspended solids, unspecified
Selenium
Waste, solid
COMPARTMENT
Air
Water
Water
Water
Water
Water
Water
Water
Waste
UNIT
S
S
S
mg
mg
MS
S
MS
kS
STUCCO, AT
PLANT/CH U (U.S.
ENERGY MIX)
139.1401881
21.86848366
24.71218062
23.66432149
7.909309986
306.2803191
23.59769783
286.8551494
3.115903858
CONVERTED TO BEES
UNITS
S
S
S
S
S
S
S
S
kS
139.1402
21.87
24.71
0.02
0.01
0.00
23.60
0.00
3.12
NOTES
Notes:
a. Accessed at: http://www.eia. doe. gov/kids/energyfacts/science/energy_calculator.html#coalcalc.
D-14
-------
APPENDIX E | POTENTIAL IMPACTS OF ALLOCATION OF
LCI RESULTS TO CCPs
-------
While the background literature (ISO framework, etc.) are relatively consistent in their discussion that
only co-products should share allocation of input and output system flows, this rule leaves out the
consideration of current and future "waste streams" that have beneficial use potential, or market value that
suggests that they may be usefully treated as co-products.
This observation is inspired by the need to consider the net impacts of CCPs in electricity generation
when looking at the life cycle impacts associated with beneficial use. While there are beneficial
substitutions possible of fly ash for cement, FGD gypsum for virgin gypsum, etc., it is possible that if the
CCPs were in fact treated as co-products instead of as wastes, that there would be non-negligible inputs
and outputs from coal-fired electricity generation that merited attention when estimating net impacts. In
this section we consider some hypothetical macro-level scenarios for coal-fired power generation, as well
as macro-level flows of several key CCPs. These scenarios are then applied in an assessment of
implications of allocating the environmental effects of power generation to both the energy product and
the CCPs.
Traditional LCA allocation rules suggest that product and co-product allocation by economic value, mass,
energy, etc., are all legitimate methods - there is no single approach to allocating that is correct. For the
first illustration, we show an approximate economic value based allocation and the resulting effects for
CCPs, followed by a prospective mass-based method.
ECONOMIC ALLOCATION
The electricity industry has about $300 billion per year in gross revenues. Roughly 50% of generation is
coal-fired at the national level. Even though the costs and revenues per kilowatt hour vary across
generation types, and the total value includes generation, transmission, and distribution, for simplicity we
assume that there is 50 percent, or $150 billion of revenues from coal-fired power generation. If we were
to adjust for the variations in price per kilowatt hour, this value would likely be closer to $100 billion
from coal-fired generation, as coal represents a lower-cost form of energy production.
From ACAA (2005) and USGS (2006), we consider the upper bound economic value of various CCPs,
using both the high end of estimated market value for the CCPs, as well as the high end estimate of CCPs
produced, and not the quantity used. Table E-l summarizes these results for the top three CCPs in terms
of market value and production.
TABLE E-1: OPTIMISTIC SCENARIO OF CCP MARKET VALUES (ACAA 2005, USGS 2006)
CCP
Fly Ash
FGD Gypsum
Bottom Ash
Total --
MARKET VALUE
(PER TON)
$45
$31
$8
CCP PRODUCTION
(MILLION TONS)
71
12
18
101
TOTAL MARKET VALUE
(ABSOLUTE UPPER BOUND)
$3.00 billion
$0.37 billion
$0.14 billion
C-1 R-I hilhnn
Summing the total value of these three products yields $3.5 billion. Even this optimistic, upper-bound
estimate is only 2% to 4% of the value of the electricity produced , if considered as shares of the total
economic value of the product (electricity) and co-products (CCPs) created by coal-fired power plants.
Of course, the values in Table E-l are highly optimistic, and USGS estimates that fly ash market value
E-1
-------
ranges from $0-45/ton, and bottom ash from $4-8 per ton. Thus, the actual economic value allocation
would likely be significantly smaller, probably less than one percent. As these were the "best case"
allocation results, it seems that allocating by economic value would lead to negligible results.
MASS-BASED ALLOCATION
The example above is straightforward in demonstrating that economic allocation is possible and feasible,
but leads to negligible results. Another alternative in LCA is to use mass-based allocation of impacts
from products and co-products of a process. In the case of CCPs from coal-fired power generation, the
product is electricity, which has no mass, which means it is impossible to purely allocate by mass.
However, as an illustration, we consider the allocation results assuming that the electricity generated is
completely tied to the combustion of coal, which has known mass. This is a simplifying but fair
assumption since there are few other significantly large mass based inputs into coal combustion processes
(process water is generally reused and returned).
If the mass-based allocation were considered as such, and thinking again at the macro-level of all coal-
fired power plants, there are about one billion tons of coal used as input. As summarized in Table E-l,
there are about 100 million tons of the top three market value CCPs, and about 120 million tons total
CCPs, generated per year by the power plants. Thus, CCPs represent about 12% of the mass, with
individual mass allocations of about 7% for fly ash, one percent for gypsum, and 0.2% for boiler slag.
Thus, in this hypothetical example, the mass-based allocations would, in fact be much larger than the
economic value allocations, but still generally a small percentage of total "mass" production. Further,
considering the other major mass flows in the plant, these numbers may, in fact, be smaller. Another
caveat is that not all CCPs produced are beneficially used. Thus, the mass allocations may converge back
to the shares estimated above for economic allocation.
SAMPLE CALCULATIONS
Given the substitution of CCPs for virgin materials production, and the potential effects of allocating
some of the environmental flows of electric power generation to CCPs, we investigated what the
comparative net effects would be if the estimated low range of mass or dollar based allocations for CCPs
(of coal-fired generation) were compared to the avoided emissions from coal fly ash and FGD gypsum
beneficial use. For simplicity we consider CO2 and SO2 emissions only.
In 2005 there were 2.5 billion metric tons of CO2 emitted in all electricity generation.81 The latest data
available from DOE that show emissions by generation type (1999) suggests that 80% of CO2 emissions
come from coal-fired generation, with an effective emissions factor of 2 Ibs/kWh (or roughly 1 short
ton/MWh).82 Assuming the same emissions rate, the 1.5 billion MWh of coal-fired generation in 2005
would have emitted 1.5 billion tons of CO2.83 Given the published 2005 emissions of 2.5 billion metric
tons CO2, this 1.5 billion metric ton estimate is less than 60% of CO2 emissions, and thus may be low.
From our overview of potential allocation values for CCPs from coal-fired generation, we estimated that
the percent allocations would be, in sum, on the order of about one percent. If we allocated one percent
of CO2 emissions from coal-fired electricity generation to the CCPs, then about 15 million (short) tons of
81 DOE, "Emissions from Energy Consumption for Electricity Production and Useful Thermal Output at Combined-Heat-and-Power Plants,"
http://www.eia.doe.gov/cneaf/electricity/epa/epat5p1.html, last accessed Aug 29th 2007.
82 DOE, "Carbon Dioxide Emissions from the Generation of Electric Power in the United States," http://www.eia.doe.gov/cneaf/electricity/
page/co2_report/co2report.html#electric, last accessed Aug 29th 2007.
83 DOE, "Emissions from Energy Consumption for Electricity Production and Useful Thermal Output at Combined-Heat-and-Power Plants,"
http://www.eia.doe.gov/cneaf/electricity/epa/epat5p1.html, last accessed Aug 29th 2007.
E-2
-------
CO2 would be allocated to their "production." In comparing this one percent allocated value to the CO2
benefits estimated separately by BEES and Simapro, we see that the avoided portland cement and virgin
gypsum use accounts for about 11.5 million short tons of CO2 emission benefits. Similarly, for SO2, coal-
fired generation leads to most electricity generation emissions, which total about 10 million metric tons
per year.84 One percent of this number is about 100,000 metric tons SO2, though this includes emissions
from all Conventional Power Plants and Combined-Heat-and-Power Plants and therefore overstates the
impact of coal combustion. However, Exhibit 5-3 in Chapter 5 of this report estimates avoided cement
and gypsum manufacturing SO2 emissions to be 26,000 short tons (23.9 million metric tons or 23.9 billion
grams), suggesting that SO2 emissions reductions associated with beneficial reuse are small when
compared with the allocated emissions impacts associated with energy production from coal.
As indicated in our high-end CO2 and SO2 examples presented above, allocated emissions from primary
production (i.e., coal combustion) may occasionally be greater than the documented benefits of beneficial
use for some metrics. However, it is important to note that this allocation procedure reflects an
accounting procedure designed only to more accurately apportion emission impacts across co-products. It
can be correctly interpreted as an indication that the beneficial use of CCPs may not be an efficient
method for reducing overall emissions of CO2 and SO2 to the environment. However, the actual CO2 and
SO2 emissions avoided from the beneficial use of coal fly ash and FGD gypsum remain positive, as
reported.
While this analysis has focused only on CO2 and SO2 (there are similar emissions from coal-fired
generation of NOx, PMi0, etc.), it demonstrates the type of framework that could be in place to help
assess the efficiency of beneficial use. It is likely that within such a framework that life cycle inventory
data would be greater for one effect and lower for others, rather than a vector dominance situation. Thus,
appropriate weighting methods should be identified to help balance the overall perceived benefit of such
substitutions. EPA's TRACI model and the BEES model itself could serve to normalize and weight
preferences of environmental flows against each other to lead to singular assessments of results.
SUMMARY
LCA allows for the allocation of input and output flows across the life cycle to the various products and
co-products of processes and systems. However CCPs are generally considered waste, and not co-
products of power generation. Even if they were considered co-products, the allocated input and output
flows from coal-fired generation would associate only very small flows to the CCPs relative to the
electricity produced. For this reason, and because our assessment here represents a high-end screening
analysis, we do not include either an economic or mass-based allocation of coal combustion impacts to fly
ash or FGD gypsum in our presentation of extrapolated findings in chapter 5.
DOE, "Emissions from Energy Consumption for Electricity Production and Useful Thermal Output at Combined-Heat-and-Power Plants",
http://www.eia.doe.gov/cneaf/electricitv/epa/epat5p1.html. last accessed Aug 29th 2007.
E-3
-------
SEPA
United States
Environmental Protection
Agency
Office of Solid Waste and Emergency Response
1200 Pennsylvania Avenue, NW
5307P
Washington, DC 20460
530-R-08-003
February 2008
------- |