United States
                               Environmental Protection
Using Coal Ash in Highway Construction:
    A Guide to Benefits and  Impacts
    April 2005


    This document was prepared by the U.S. Environmental Protection Agency (EPA),
    in cooperation with the following agencies and associations:

    Department of Energy (DOE)

    Federal Highway Administration (FHWA)

    The American Coal Ash Association (ACAA)

    The Utility Solid Waste Activities Group (USWAG)

                      III PC11C1I13
Alkali-Silicate Reactivity: The reaction between the alkalies (sodium and potassi-
um) in Portland cement with certain siliceous rocks and minerals, such as opaline
chert, strained quartz, and acidic volcanic glass, present in some aggregates; the
products of the reaction can cause abnormal expansion and cracking of concrete in
service. Class F fly ash is used in concrete to reduce the occurrence of alkali-silica

Attenuation: The reduction in  mass or concentration of a compound in ground
water over time or distance from the source of constituents of concern due to nat-
urally occurring physical,  chemical, and biological processes, such as biodegreda-
tion, dispersion, dilution,  adsorption, and volatilization.

Beneficial Uses: The use  of byproducts in such a manner that the material serves a
beneficial function, while not  adversely impacting human health or the environ-
ment. Beneficial uses of byproducts include construction applications (e.g., brick
and concrete products, road bed, blasting grit, wall board, insulation, roofing mate-
rials), agricultural  applications (e.g., as a substitute for lime) and other applications
(e.g., absorbents, filter media, paints, plastics and metals manufacture, snow and
ice control, waste stabilization).

Borrow Pit: An area from which soil is excavated for use as a  fill material in a high-
way application.

Cement Clinker: The fused particles or pellets produced from the sintering or burn-
ing zone (2200° F to 2700° F) of a rotary kiln in the cement manufacturing process.
Raw materials (limestone, shale, iron ore, sand) are proportioned and ground to a
powder and blended before being processed through the rotary kiln.

Coal Combustion Products (CCPs): Residues from coal burning, including bottom
ash, fly ash, boiler slag, and flu gas desulfurization materials (FGD), which can be
used beneficially.  (The use of the term "coal combustion products" in this docu-
ment does not change the legal definition of solid waste as defined in RCRA 42
U.S.C.  6903(27).)

Concrete: A construction material consisting primarily of aggregates,  Portland
cement,  and  water. Certain coal ashes can be used as a replacement for a portion
of the Portland cement.

Engineered Application: Use of a byproduct that has been specifically designed and
engineered (for example, a road design that incorporates appropriate run-off con-
trol and provides adequate strength for the required use).

Fill: Material such as dirt, gravel, or coal  ash used to build up an area of land.

Flowable Fill: A fill material that flows like a liquid, is self-leveling,  requires no  com-
paction or vibration to achieve maximum density, hardens to a predetermined
strength, and is sometimes used as a controlled low-strength material.

Flue Gas Desulfurization  Materials (FGD):  The materials created during the process
of removing gaseous sulfur dioxide from boiler exhaust gas.  FGD materials often
are used as a replacement for gypsum in wallboard.

Heat of Hydration: Heat evolved by chemical reactions with water  such as during
the setting and hardening of  Portland cement.

Leachate:  The liquid,  including any suspended components in the liquid, that has
percolated through or drained from a pile or cell of solid materials; the liquid
stream that issues from  a pile or cell of solid materials and that contains water,
dissolved solids, and  decomposition products of the solids.

Maximum Contaminant Level  (MCL): The highest level of a contaminant that is
allowed in drinking water.

Portland Cement: A hydraulic cement made by heating  a mixture of limestone  and
clay containing oxides of calcium, aluminum, iron, and silicon in a kiln and pulveriz-
ing the resulting clinker.

Pozzolanic Properties: The phenomenon of strength development that occurs when
lime and certain aluminosilicates  react at ambient temperatures in the presence of

Sulfate Attack: Either a chemical  or physical reaction (or both) between sulfates,
usually in soil or ground water, and concrete and mortar. The chemical reaction is
primarily with calcium aluminate hydrates in the cement-paste matrix and can
cause deterioration of the cement product.

ii™^;;;0^^  s^.** •'

                 In ancient times, the Romans added
                 volcanic ash to concrete to strengthen
                 structures such as the Roman Pantheon
                 and the Coliseum—both of which still
                 stand today.

                 The first major use of coal fly ash in  con-
                 crete in the United States occurred in
                 1942 to repair a tunnel spillway at the
                 Hoover Dam.

                 One of the most impressive concrete
                 structures in the country, the  Hungry
                 Horse Dam near Glacier National Park
                 in Montana, was constructed from 1948
                 to 1952, with concrete containing
                 coal fly ash.

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                                                       In Washington, DC, both the metropol-
                                                       itan area subway system (Metro) and
                                                       the new Ronald Reagan Building and
                                                       International Trade Center were built
                                                       with concrete containing coal fly ash.

                                                       Other significant structures utilizing
                                                       coal fly ash in concrete include the
                                                       "Big Dig" in  Boston and the decks
                                                       and piers of Tampa Bay's Sunshine
                                                       Skyway Bridge.

     Using  Coal        in
            A       to         nl
         The U.S. Environmental Protection Agency (EPA) encourages the use of
         coal combustion products (CCPs) in highway construction projects such
         as in concrete, road base, embankments, flow/able fill, and other benefi-
cial applications. The increased use of these materials, which would otherwise be
discarded as waste, can reduce greenhouse gases in the atmosphere, reduce
energy consumption, and conserve natural resources. Some applications, such as
road embankments and other non-encapsulated  (loose) uses, may require the eval-
uation of local hydrogeological conditions to ensure protection of human health and
the environment.

To encourage the increased use of coal combustion products, EPA, the Department
of Energy, and the Federal Highway Administration, along with the American Coal
Ash Association and the Utility Solid Waste Activities Group, are co-sponsoring the
Coal Combustion Products Partnership (C2P2). The purpose of C2P2 is to foster the
beneficial uses of coal  combustion products. This booklet is intended to help users
and the public understand both the environmental benefits and potential impacts
of using coal combustion products in various applications. EPA and the National
Academy of Sciences are evaluating the use of coal combustion products as mine-
fill and will address this issue separately.

Background Basics	3
    What Are Coal Combustion Products?	3
    How Are Coal Combustion Products Used?	4
    How Are Coal Combustion Products Used in Highway Applications?	6
    What Are the Engineering Performance Standards for Using Coal Ash in Highway
    Construction?	8
    Are There State Requirements for Using Coal Ash in Highway Construction?.... 9

Performance and Cost Benefits	12
    In Concrete	12
    In Embankments	13
    In Flowable Fill	13
    In Stabilized Base Course	14
    In Asphalt Pavements	14
    In Grouts for Pavement Subsealing	14

Environmental Benefits	16
    Greenhouse Gas Emissions and Energy Reductions	16
    Resource Conservation	18
    Solid Waste Reduction	19

Environmental and Health Cautions Associated with Concrete
(Encapsulated) Uses	20
Environmental and Health Cautions Associated with
Unencapsulated Uses	21
    Water Issues: Groundwater/Surface Water Health and Human Ingestion	22
    Vegetation and Food Chain Issues	26

    Air Issues: Air Quality and Inhalation	26
    Occupational Issues: Inhalation and Skin Contact	27

EPA's Position on the Use of Coal Combustion Products	30
    Regulatory Determinations	30
    Procurement Policy	31

Case Studies	32
    Concrete Pavement:
    Cold In-Place Recycling of Asphalt Pavement, Jackson County, Missouri	32
    Boston Central Artery/Tunnel Project, Massachusetts	33
    Road Base:
    State Route 22 Project, Georgia	34
    Route 213/301 Overpass Project, Maryland	34
    Access Ramp Project, Delaware	35
    Flowable Fill:
    McGee Creek Aqueduct Pipe Bedding Project, Oklahoma	36
References and Other Sources	37

                                                Background Basics
                                        The concentrations of naturally
                                        occurring elements found in many
                                        fly ashes are similar to those
                                        found in naturally occurring soil.
Background  Basics

What Are  Coal  Combustion  Products?

                When coal is burned in a power plant to generate electricity, it leaves
                behind residues that can be used as products or raw materials, pri-
                marily in the construction industry. These materials are known as coal
    combustion products, or CCPs. Power plants generate a variety of CCPs, namely bot-
    tom ash, fly ash, boiler slag, and flue gas
    desulfurization (FGD) materials. EPA and
    industry refer to the larger ash particles
    that fall to the bottom of a furnace as
    bottom ash, and ash that is  carried
    upward by the hot combustion gases of the furnace as fly ash.  Boiler slag is formed
    instead of bottom ash when combustion occurs in a wet boiler, and FGD materials
    are produced from scrubbers used to remove sulfur from air emissions.

    The concentrations of naturally occurring elements found in many fly ashes are
    similar to those found in naturally occurring soil. A mineral analysis of coal combus-
    tion products from coal-fired power plants indicates that they are composed of 95
    percent iron oxides, aluminum, and silica. They also contain oxidized forms of other
    naturally occurring elements found in coal, such as arsenic, barium, cadmium,
    chromium, copper, lead, mercury, selenium, and zinc. The exact chemical composi-
    tion of coal combustion products varies depending on the type of coal burned, the
    extent to which the coal is prepared before it is burned, and the operating condi-
    tions for  combustion.

Figure 1: Typical Steam Generating System
Note: SCR-Selective Catalytic
Reduction DeNOx System FGD-Flue
Gas Desulfurization System
                                              FGD Byproduct

          Using  Coal  Ash in  Highway Construction
                A Guide to Benefits and Impacts
How Are Coal Combustion Products Used?

    According to the American Coal Ash Association's annual coal combustion product
    survey, almost 122 million tons of coal combustion residues were generated in 2003,
    and more than 46 million tons were used as products in such beneficial applications
    as concrete, roofing tiles and shingles, bricks and blocks for building construction,
    wallboard, and specialty uses such as filler in carpet and bowling balls. Figure 2
    shows the top uses of coal combustion products, and Figure 3 shows the top uses
    of coal fly ash specifically for the reporting year 2003. These figures show that the
    number one use of coal combustion products collectively, and coal fly ash specifical-
    ly, is in cement, concrete products, and grout. Figure 4 presents the total coal com-
    bustion product generation and use in 2003 by type of material.  This figure shows
Figure 2: Top Uses of Coal Combustion Products, 2003
             Snowand Ice Control
               788,184 Tons
          Blasting Grit/
         Roofing Granules
         1,497,744 Tons

      Road Base/Sub-base/

       Mining Applications
        2,330,032 Tons
        3,956,973 Tons
         Waste Stabilization/
           3,999,623 Tons
Soil Modification/Stabilization 773,076Tons

    Aggregate 687,839 Tons
           Other 2,042,037 Tons
                                 7,780,906 Tons
                                12,679,134 Tons
                                 Structural Fill/
                                8,187,469 Tons
         * EPA and the National Academy of Sciences are evaluating the use of coal combus-
          tion products as minefill and will address this issue separately.
         Source: American Coal Ash Association. 2004.

                                                         Background Basics
     that for most coal combustion materials, the United States is beneficially using only
     about a third of the material generated, with the exception of boiler slag, which
     shows a 95 percent usage rate.

     Coal combustion products have also been used as minefill material. EPA and the
     National Academy of Sciences are evaluating the use of these materials as minefill.
Figure 3: Top Uses of Coal Fly Ash, 2003
               Road Base/Sub-base/Pavement
                      493,487 Tons

          Soil Modification/Stabilization
                515,552 Tons
               Mining Applications
                 683,925 Tons
       3,024,930 Tons
L Aggregate 137,171 Tons
      Mineral Filler in Asphalt 52,608 Tons
                                                                  12,265,169 Tons
    Waste Stabilization/
     3,919,898 Tons
                         Structural Fill/
                        5,496,948 Tons
         * EPA and the National Academy of Sciences are evaluating the use of coal combus-
           tion products as minefill and will address this issue separately.
         Source: American Coal Ash Association. 2004.

        Using  Coal  Ash in Highway Construction
             A Guide to Benefits and Impacts
Figure 4: Coal Combustion Product Generation and Use (Short Tons), 2003

                                                    Percent Used
               	      Fly Ash          38.7%
 «                                      Bottom Fly Ash     45.6%
                                        Boiler Slag       95.6%
    45,000,000     •              —FGD Material      29.1%

                                        Other           33.1%

                     Total Production               Total Use
              Source: American Coal Ash Association. 2004.

How Are  Coal  Combustion Products
Used  in  Highway  Applications?

   The two types of coal combustion products used most often in highway construc-
   tion are fly ash and bottom ash. Fly ash can be used as a replacement for Portland
   cement in concrete and grout, as a fill material in embankments, as aggregate for
   highway subgrades and road base, and in flowable fill. Bottom ash can  be used as
   aggregate in concrete and in cold mixed asphalt, and as a structural fill for
   embankments and cement stabilized bases for highway construction. Figure 5
   presents details on coal combustion product use for the 2003 year, with highway
   applications shaded.

                                                    Background  Basics
Figure 5: Details of Coal Combustion Product Use (Short Tons), 2003
Highway Applications are shaded.

Structural fills/embankments
Cement/raw feed for cement
Road base/sub-base/pavement
Snow and ice control
Flow/able Fill
Mineral filler in asphalt
Wall board
Waste stabilization/solidification
Mining applications**
Blasting grit/roofing granules
Soil modification/stabilization
Fly Ash Bottom Ash Boiler Slag



Source: American Coal Ash Association. 2004.
* Flue gas desulfurization materials include FGD gypsum, FGD material wet scrubbers, FGD materi-
  al dry scrubbers and FGD other.
** EPA and the National Academy of Sciences are evaluating the use of coal combustion products
   as minefill and will address this issue separately.

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       The American Society for Testing and Materials (ASTM) and the American
       Association of State Highway and Transportation Officials (AASHTO) have issued
       numerous standards that describe the proper use of bottom and fly ash in engi-
       neering activities.

       The standard for using fly ash in Portland cement concrete—the most common
       type of coal combustion product used in highway construction and the most com-
       mon usage—is ASTM C 618, or the very similar AASHTO M 295. Two classes of
       fly ash are defined in ASTM C618: Class F and Class C. These classifications are
       related to the amount of free lime or calcium oxide in the ash  and the grade of
       coal. Both Class F and Class C fly ash have pozzolanic  properties—in other words,
       they react with water and free lime  (calcium oxide) to produce a cement-like com-
       pound.  Class F fly ash typically contains from 2 to 6 percent calcium oxide and
       requires additional lime to obtain self-hardening properties.  Class C fly ash typically
       contains between  15 and 35 percent calcium oxide and does  not require additional
       lime for self-hardening properties.

The Standard Guide for Design and Construction of Coal Ash Structural Fills, ASTM
E2277-03, addresses the second largest use of coal fly ash. This document
includes guidelines on using coal ash for structural fill applications (road embank-
ments and other uses), site characterization considerations such as geologic and
hydrologic investigations, laboratory  test procedures, design considerations and
methods, and construction considerations. This guide replaces ASTM E 1861-97.
For more information concerning the ASTM and AASHTO standards that apply to
coal ash use in highway construction see the Federal Highway Administration's
June 2003 document, Fly Ash Facts  for Highway Engineers.
                                        States with CCP Laws, Regulations,
                                               Policies, or Guidance
Many states have laws, regulations, policies, or guidance authorizing or allowing at
least limited use of coal combustion products in highway construction. For
instance, Wisconsin's Department of Natural Resources has developed a largely
self-implementing regulation (NR 538
Wis. Adm. Code), which includes a
five-category system to allow for bene-
ficial use of industrial byproduct materi-
al, including coal ash.1 (See sidebar on
page 10.) The Texas Natural Resource
Conservation  Commission issued guid-
ance in  1995  that defined coal combus-
tion products as "co-products" instead
of waste when  used  in certain applica-
tions in  accordance with industry stan-
dards. Many other state regulations
adopt by reference the federal regula-
tion, which exempts coal combustion
products from classification as haz-
ardous waste. For additional informa-
tion on applicable regulations, contact
your local and state authorities.
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
West Virginia
' See .

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         Wisconsin's Beneficial Use of Industrial
         Byproducts Waste Management  Program

                  Wisconsin's Beneficial Use of Industrial Byproducts
                  Program is a state-authorized voluntary environmental
                  program that encourages the beneficial use of coal ash,
         boiler slag, paper mill sludge, foundry sand, and foundry slag as
         alternatives to placing these materials in the  state's solid waste
         landfills. For the reporting year 2000, the Wisconsin Department
         of Natural Resources (WDNR) showed that participating genera-
         tors generated more than 1.4 million tons of coal ash and boiler
         slag and beneficially used more than 1.1 million tons (81 per-
         cent). WDNR also estimated that, statewide (including facilities
         not participating in the program), nearly 72 percent of coal ash
         and boiler slag generated in the state is beneficially used. In
         contrast, the American Coal Ash Association reported that only
         29 percent of the coal ash generated nationally in 2000 was ben-
         eficially used.
         Wisconsin's beneficial use program began  in 1985 when the
         state legislature gave WDNR authority to issue landfill exemp-
         tions for low-hazard wastes. In 1995, this authority was expand-
         ed to allow WDNR to develop a program and rule for certain
         industrial byproducts. The result was enactment of State Law NR
         538, "Beneficial Use of Industrial Byproducts." The law includes
         five different categories of industrial byproducts, determined by
         the chemical characteristics of the materials, defines acceptable
         end uses for each category, and provides 12 pre-approved bene-
         ficial uses for the materials.
         For small private projects (<5,000 cu. yds. of material), genera-
         tors may use their byproducts in a pre-approved  beneficial use
         without contacting WDNR. For large private or public projects,
         generators must notify WDNR of the nature of the project and
         provide information about the material characteristics. WDNR
         reserves the right to review any of these projects, but no permit
         process beyond notification is required.

 To ensure success, WDNR used a technical advisory committee to
 help develop the program, including WDNR representatives from
 all of the district offices, representatives from the generator
 community, the Department of Transportation, Sierra Club and
 other environmental groups, and a number of general contrac-
 tors that perform aggregate construction work. Because most of
 the affected entities were part of the development process, the
 program was not challenged in public hearings or in court. In
 addition, the rule was coordinated with Department of
 Transportation requirements, and liability issues were addressed.
 Another key to the success of the program is that it is largely
 self-implementing. Generators can conduct their own material
 testing and can proceed without state approval for uses covered
 by the law. The self-implementing aspect of  the program was
 important to the generator groups on the committee; these
 groups were willing to balance the advantages of self-implemen-
 tation with the disadvantages of recordkeeping and reporting
 requirements included in the law.
 NR 538 became effective in June 1998. Its success can be meas-
 ured by the high percentage of coal ash and slag use throughout
 the state, compared to the national average. In addition, no
 environmental issues or problems have been associated with the
 implementation  of the program.                            ,
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           Using Coal Ash in  Highway Construction
                A Guide to Benefits and Impacts
  Performance  and  Cost  Benefits
                                         Why Is Coal Fly Ash Useful?

                                         The physical properties of coal fly ash—
                                         specifically, the unique spherical shape
                                         and particle size distribution—make it a
                                         good mineral filler in hot-mix asphalt
                                         applications, improve the fluidity of flow-
                                         able fill and grout, and reduce the perme-
                                         ability of concrete.
I            sing coal combustion products
            in highway construction yields
            a number of performance and
    cost benefits, which can lead to environ-
    mental benefits as well. Performance
    benefits can be realized from the use of
    coal ash in concrete mixtures, embank-
    ments, in flowable fill, as a stabilized
    base course, in asphalt pavements, and
    in grouts for pavement subsealing.

In Concrete
      Coal ash can be used to create superior products because of its inherent cementi-
      tious properties. Mixing fly ash with Portland cement mixtures can produce
      stronger and longer lasting roads and bridges than concrete made with only
      Portland cement as the binder (glue). The following are notable performance bene-
      fits from using coal fly ash in concrete:

Figure 6: Strength Gain of Fly Ash Concrete
         Improved workability of concrete due to the nature and shape of the ash particles

         Reduced water demand

         Reduced bleeding at the edges of pavement

         Increased ultimate strength of the concrete

         Reduced permeability to moisture, improving long-term durability of the concrete

»>  Decreased heat of hydration during concrete curing
i»  Greater concrete resistance to various forms of deterioration
»>  Reduced concrete shrinkage
Fly ash can be used as a borrow material for highway embankments. When fly ash
is compacted, a structural fill can be constructed that can support highways. The
performance benefits associated with this use include:
*> Elimination of the need to purchase, permit, and operate a borrow pit
»> Placement over low-bearing-strength soils
*> Ease of handling and compaction, which reduces
   construction time and equipment costs
Flowable fill made with coal fly ash can be used in place of conventional backfill
materials and alleviates problems and restrictions generally associated with the
placement of those materials. Benefits include:
*>  Placement in any weather, including  under freezing conditions
»>  100 percent density with no compactive effort
*!*  Ability to fill around and  under structures inaccessible
    to conventional fill  placement techniques
<»  Increased soil-bearing capacity
»*»  Prevention of post-fill settlement problems
<»  Increased speed and ease of backfilling operations
»*»  Decreased variability in the density of backfilled
i»  Improved on-the-job safety and reduced labor and
    excavation costs
»>  Easy excavation later when properly designed

       Fly ash and lime can be combined with aggregate to produce a quality stabilized base
       course. These road bases are referred to as pozzolanic-stabilized mixtures and are
       advantageous over other base materials because they provide:

       »> A strong durable mixture

       »t» Reduced costs

       »> Autogenous healing

       »t» Increased energy efficiency
       Fly ash also can be used as a mineral filler in
       asphalt pavements. Mineral fillers increase the
       stiffness  of the asphalt mortar mix, improve
       the rutting resistance of pavements,  and
       improve the durability of the mix. Other bene-
       fits include:

       #  Reduced potential for asphalt stripping

       •>  Reduced cost compared to other
           mineral fillers
       Grouts for pavement subsealing are proportioned mixtures of fly ash, water, and other
       materials used to fill voids under a pavement system without raising the slabs by
       drilling and injecting grout under specified areas of the pavement. In these applica-
       tions, the performance benefits include:

       »>  Quick correction of concrete pavements

       «t»  Minimal traffic disturbance

       «>  Development of high ultimate strength

In addition to these performance benefits, many coal combustion products are less
costly to use than the materials they
replace. At the same time, the durabili-
ty benefits from using coal ash con-
crete can reduce the cost of maintain-
ing the nation's road systems. This
enhanced performance also provides additional environmental benefits by reducing
the need for new concrete to replace aging roads and  bridges, thereby significantly
reducing future energy consumption and greenhouse gas emissions.
The California Department of
Transportation requires the use of
concrete containing fly ash in all of
its roadways to improve durability.
  Over the past 15 years, the Federal Highway Administration (FHWA) and its partners in
  state highway agencies, universities, and the pavement industry have achieved tremen-
  dous advances in pavement technology. The FHWA's Office of Pavement Technology
  has been focusing on combining recent technical advances to develop long-life pave-
  ment systems that can last up to 50 years for roads—twice the lifetime of conventional
  pavements. These long-life pavements will reduce the costs of maintaining the nation's
  highway systems and also result in decreased material needs. Coal fly ash and other
  recycled materials are common components of these high-performance Portland
  cement pavements.

          Using Coal  Ash in  Highway Construction
                A Guide to Benefits and Impacts
  Environmental  Benefits

              The use of coal combustion products in highway construction provides
              significant short- and long-term environmental benefits. Specifically,
              using coal combustion products in lieu of other materials, such as
      Portland cement, reduces energy use and greenhouse gas emissions and con-
      serves natural resources. In addition, it prevents the disposal of a valuable
      resource, reducing the need for landfills and surface impoundments. Finally, the
      inherent performance benefits of concrete made from coal ash actually leads to
      additional environmental  benefits. Highways and bridges made with coal ash con-
      crete are more durable than those made without it and, therefore, do not need to
      be repaired and replaced as often.

  Greenhouse Gas Emissions and Energy

      Producing cement involves many steps, including grinding and blending raw  ingre-
      dients (such as limestone, shells or chalk, and shale, clay, sand, or  iron ore), heat-
      ing those ingredients to very high temperatures in a kiln, cooling and mixing  those
      ingredients with gypsum, then grinding down the mixture to form cement powder.

  Figure 7: Generic Cement Production  Process
Water—»• Slurry—>• Grinding


                                                  •  Mix
         Dry Raw Materials

      This energy-intensive process typically emits nearly one ton of greenhouse gases
      for each ton of cement created and requires the equivalent of a barrel of oil per

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ton. Using fly ash—which would other-
wise be disposed of—in concrete has
the potential to significantly reduce the
quantity of greenhouse gases emitted
and the amount of fuel used. Typically,
between 15 to 30  percent of Portland
cement in concrete can be replaced
with fly ash.

The Federal Highway Administration
reports that roads  and bridges made
with high-performance coal ash con-
crete can last  years longer than those
made with Portland cement as the only
binding agent. Thus, using coal ash
concrete reduces the need to produce
new concrete, which consequently
 What Are Greenhouse Gas

The Earth's atmosphere acts like an
immense greenhouse, trapping heat from
the sun to warm the planet to create
habitable conditions. This "greenhouse
effect" occurs when solar radiation  is
absorbed by greenhouse gases in the
atmosphere. Most greenhouse gases,
such as carbon dioxide, nitrous oxide, and
other trace gases like methane, occur
naturally. Human activities may intensify
this natural phenomenon. Burning fossil
fuels to power cars, homes, and industry
releases carbon dioxide and increases con-
centrations of other greenhouse gases in
the atmosphere.
means further reductions in future
greenhouse gas emissions, energy use, and natural resources. For some locations,
coal combustion products are a locally available construction material that requires
less transportation costs and fuel usage
for trucking the material to the con-
struction site.
In 2002, the American Coal Ash
Association estimated that 12.6 million
tons of fly ash were used as a substi-
tute for Portland cement in the United
States. The industry set a  goal to
increase its use to 20 million tons by
2010. EPA estimates that this would
reduce the future generation of green-
house gasses by more than 6.5 million
tons a year.2
    Conserves enough landfill space to
    hold about 1,200 pounds of waste, or
    the amount of solid waste produced
    by one American over 270 days.

    Reduces the equivalent of two
    months of an automobile's carbon
    dioxide emissions.

    Saves enough energy to provide elec-
    tricity to an average American home
    for 19 days.
2 Estimated using EPA's Waste Reduction Model, Solid Waste Management and
Greenhouse Gases, Second Edition, EPA 530-R-02-006,  Office of Solid Waste, June 2002.

                                    •  ,;• '  K,.r
       Because coal ash can be used as a replacement for many materials in highway
       construction, its use reduces the need to quarry or excavate virgin materials and
       therefore helps to reduce the  environ-
       mental impacts associated with these
       activities. Reducing these operations
       helps prevent habitat destruction, pro-
       tect scenic waterways, reduce water
       runoff and air emissions, and reduce
       energy use. In addition, each ton of
       coal ash used beneficially reduces the
       need for one ton of virgin resources.
Coal combustion products can be substi-
tuted for many virgin resources that
would otherwise have to be quarried or
excavated, such as:

    Limestone and clay to make concrete

    Gypsum to make wallboard

    Sand and gravel to make road beds

    Soil for road embankments

                                          Environmental Benefits

Solid Waste  Reduction

    Although many U.S. industries are using coal combustion products, the United
    States continues to dispose of more than 80 million tons of this material in landfills
    and surface impoundments annually.
    Using coal ash as a substitute for
    cement in highway construction and
    other applications could reduce this
    waste. Typically, a  ton of coal ash com-
    pacted to 70 pounds per cubic foot
    takes up approximately 28 cubic feet of
    landfill space. Every million tons of coal
    combustion products beneficially used
    instead of disposed of reduces the need for  656 acre-feet of landfill space. Figure 8
    shows U.S. trends in  the generation and use of coal combustion products over the
    past several years. These data indicate that  while the beneficial use of coal com-
    bustion products is increasing slowly, so has the  generation of these materials.

Figure 8.  Production and Use of Coal Combustion Products, 1996-2003



 <2  100,000
I Production
              1996   1997   1998   1999   2000   2001   2002    2003
 Percentage    24.9%   27.8%  29.0%  30.8%  29.1%   31.5%  35.4%   38.1%

         '   -: !/,   ;•;'hen coal ash is used in concrete for building roads and bridges, its
        "«;•  " . ' ;;<•' constituents—such as heavy metals—are bound (encapsulated) in
        ' -'' x"1 <     5- >
         '•   "   '•     the matrix of the concrete and are very stable. Leaching of these
       constituents for all practical purposes does not occur.3

       Occupational issues associated with coal
       ash use in concrete include the handling of
       dry coal ash prior to or during its inclusion in
       a concrete mix or exposures during demoli-
       tion of  concrete structures. In these cases,
       work inhalation and skin contact  precautions
       should  be observed, as described on page
       27 in the section called Occupational Issues:
       Inhalation and Skin Contact.
         U.S. Environmental Protection Agency. March 1999.

;•"".''"  tudies and research conducted or supported by Electric Power and
''•"'.„.„'\ Research Institute (EPRI), government agencies, and universities4 indicates
• '"•••'":,/ •- 'that the beneficial uses of coal combustion products in highway construc-
tion have not been shown to present significant risks to human health or the envi-
ronment. But, as with many other common substances, precautions and sound
management practices should be applied when using coal ash in unencapsulated
uses. Water and air are the two media most likely to be affected by coal ash or
coal  ash constituents.

Ingestion, inhalation, and skin contact are the ways that humans and other living
things could be  exposed to coal ash. Other issues that may need to be addressed
are leaching of elements such as mercury and metals into ground water, contami-
nation of vegetation and the impact of other  elements on the food chain, and air-
borne dust. In most cases, however, the way that coal ash is used, the engineering
requirements for that use, and the handling and management methods applied
minimizes exposure to the ash.
  EPRI. May 1990, December 1990, February 1991, November 1993, June 1995, March
  1998, and 1998; Hassett, David J., et al 2001; Pflughoseft-Hassett, D.F., et al. 1993; U.S.
  Environmental Protection Agency. August 9, 1993.

           Using  Coal  Ash  in  Highway Construction
                 A Guide to Benefits and Impacts
    Although mercury in coal ash can potentially be released into the environment through
    leachate in water or as emissions to the ambient air, studies conducted by the University
    of North Dakota Energy and Environmental Research Center and the University of
    Nevada, which tested bituminous, subbituminous, and lignite coals, have shown that
    mercury releases from coal ash to the environment are negligible.s Results from water
    leachate tests showed that mercury was very stable in coal fly ash and leached less than
    1 percent of the initial mercury concentrations. Studies on the release of mercury from
    coal ash to the ambient air show only minute losses to the environment.

    EPA has proposed a new regulation, called the Clean Air Mercury Rule (CAMR), that
    would require reductions in mercury emissions from coal-fired power plants. This pro-
    posed regulation might affect the amount of mercury found in coal ash, but whether
    this regulation will increase mercury concentrations in coal ash or not is not clear at this
    time because this is the first time ever that EPA has regulated mercury emissions from
    power plants. EPA's  conclusions in this document are based on the regulations currently
    affecting power plants. EPA will reassess its position, if it appears that there is a signifi-
    cant increase in the level of mercury in coal ash, when the CAMR is promulgated.

  Water Issues:  Groundwater/Surface

  Water Health  and Human Ingestion

      Several studies6  over the past 10
      years have shown that the use of
      coal ash in highway construction
      projects has resulted in little to no
      impact on groundwater and
      surface water quality, but some
      precautions are necessary.

      Road Beds and Embankments: Coal ash used as a fill for road beds and embank-
      ments, unlike that used in concrete, requires greater care to ensure its safe use.
      The use of engineering standards and guidelines pertaining to coal ash will help
      ensure that the use of these materials will not negatively impact the environment.
        Hassett, David J., et al. 1999.
        EPRI. May 1990, December 1990, February 1991, November 1993, June 1995, March
        1998, 1998; Hassett, David J., et a/200/; Pflughoseft-Hassett, D.F., et al. 1993; U.S.
        Environmental Protection Agency. August 9, 1993.

                        C.: TI v:' if ®- IT mi ;'?• ii t a 1

Environmental issues in these cases are largely determined by local circumstances,
such as groundwater depth  and proximity to drinking water wells. The studies
mentioned above show that while
leaching of coal ash constituents is          Precautionary Measures
possible from unencapsulated uses,      Associated until Jtaencapsulted
it does not occur in practice at high
concentrations and has not been        •  Assess hydrogeologic characteristics of
shown to migrate far from the site         the sitei
when appropriate engineering prac-     •  Mitigate leaching through engineering and
tices are followed                        design practices and follow proper construc-
                                        tion techniques.
Despite the relative safety of using      .  Unencapsu|ated coa, asn can be used wnen
coal combustion products in unen-         an assessment indicates it will not affect
Capsulated highway construction           gr0und or surface waters. An assessment is
projects, Some preventive and Cau-        particularly important in areas with sandy
tionary measures Should be  taken          soils, shallow ground water or in close prox-
(See Town Of Pines Case Study On          imity to drinking water aquifers
page 24):

1) Conduct an evaluation of  local groundwater conditions prior to using coal com-
   bustion products as a fill material. Numerous groundwater models are available,
   such as EPA's Industrial Waste Evaluation Model (IWEM), a groundwater fate
   and transport risk assessment model in EPA's Guide for Industrial Waste
   Management, and HYDRUS 2D.7

2) Consult with  your state regulatory agency for information on the applicable test
   procedures, water quality standards, and other  requirements.

3) Once you  determine that  a site is appropriate for coal ash use, mitigate the
   leaching of coal ash constituents by assuring adequate compaction and grading
   to promote surface water runoff, and daily proof-rolling of the finished subgrade
   to impede infiltration. When construction is finished, a properly seeded soil
   cover will  also help. Two helpful sources of construction information are state
   highway departments and the Federal Highway Administration's June 2003
   document, Fly Ash Facts for Highway Engineers.
  IWEM model available at www.epa.gov/epaoswer/non-hw/industd/iwem.htm; HYDRUS
  2D model available at www.hydrus2d.com.

                        ••"" ,    "    '," -'    ".   '

                  .:, '."I! 10
         The Town of Pines, Indiana, provides a cautionary lesson on
         waste disposal and the use of coal ash as general fill in
         vulnerable areas. It is primarily a story about the groundwater
         contamination that arose because of poor early disposal
         practices. It demonstrates several lessons on the need for good
         coal combustion product construction practices and site charac-
         terization when the material is not encapsulated—specifically,
         assessing potential groundwater impacts.
         Pines is located about two miles south of Lake Michigan,
         adjacent to Dunes National Lakeshore. The town's drinking
         water comes from shallow residential wells typically drawing
         ground water from 25 to 50 feet below ground level. The native
         soils are sandy, unconsolidated, and highly acidic, with a high
         organic content overlying a less permeable clay-rich layer.
         Since 1983, more than a million tons of coal ash and other mate-
         rials have been disposed of at a local  landfill or used around
         town as a fill material. The landfill was originally located in a
         swampy area only 300 feet from the nearest drinking water well
         and has recently closed. The direction of groundwater flow is to
         the east/northeast with a small northerly component that affect-
         ed the main portion of the Town of Pines. Coal ash was also
         used throughout the town to fill in low lying areas—up to eight
         feet in some places—and to build roads that were often left
         uncovered and exposed to the elements. The shallowness of
         Pines's drinking water aquifer makes it susceptible to contami-
         nation of all types.
         In May 2000, the Indiana Department  of Environmental
         Management (IDEM) began an investigation of the town's water
         after a resident complained that it tasted foul. IDEM found sev-
         eral volatile organic compounds (VOCs) in the water, including

                        Environmental and Health Cautions
benzene. In January 2001, IDEM also found elevated levels of
methyl-tertiary-butyl-ether (MTBE). Both benzene and MTBE are
associated with gasoline and are not associated with the landfill
or coal ash. Later investigations discovered high levels of boron,
manganese, and molybdenum  in the drinking water, which are
associated with coal ash. In short, the shallowness of the drink-
ing water wells, the porosity of the overlying sands, the location
of the landfill, and the improper use of coal ash all contributed
to the contamination of the town's drinking water.
Several important lessons can be learned from Pines:
  Take care when using or disposing of any material in a hydroge-
  ologically vulnerable area.
  Before using coal ash as a fill material, conduct an assessment
  of its potential groundwater impacts.
  Follow proper engineering requirements when using unencap-
  sulated coal ash.
The environmental problems in the Town of Pines should not dis-
courage the beneficial use of fly ash at other locations for fill,
road base, or embankments. But, these problems do highlight
the need for properly assessing and addressing potential
groundwater impacts.     '*

       EPA, in 2000, determined that the use of coal ash as a highway fill material or even
       as a substitute for lime in agricultural applications did not pose a risk of concern. In
       addition, several EPRI (Electric Power Research lnstitute)studies8 have shown that
       the use of coal ash in unencapsulated highway construction projects poses limited
       risk to roadside vegetation. Studies of road construction projects in Arizona,
       Arkansas,  Georgia,  Illinois, and Kansas indicate that while metal constituents from
                               coal fly ash and bottom ash might enter plant tissues
                               through absorption, the concentrations of these elements
                               are found to be well below the toxic limits.

                               In addition, studies examining the effects of ingestion of
                               fly ash  constituents by animals have not suggested any
                               associated health problems.9 Some tests showed slightly
                               elevated levels of some elements in blood and various
                               organs, while other tests found no constituent increases.
                               These results indicate little potential for coal ash  ele-
       ments from highway construction projects to accumulate in soil and increase in
       concentration by food chain biomagnification (the process by which animals feed-
       ing on affected plants can,  in  turn, accumulate the  same constituents and  build up
       these constituents in their tissues).
               n in -
                                                           t III i- •
       Air inhalation of coal ash dust is primarily a worker safety issue. Nevertheless, proper
       precautions should be taken to  protect the public from dusting during delivery and
       construction, when coal ash is first laid down. Dust is not an issue when coal ash is
       used in concrete or in a slurry form.

       Coal ash can become airborne  during storage and
       processing of ash, from traffic  on roads, and
       through wind erosion during ash placement. Like
       other nuisance dust,  however,  specific controls
       can address these exposure methods to prevent
       air pollution and  inhalation:
        Electric Power Research Institute. June 1995.
        Electric Power Research Institute. 1998.

                               :nviron _
        High-calcium, self-hardening ash
        should be stored dry in silos, while
        low-calcium ash can be stockpiled
        onsite if the ash is kept moist and
        covered to prevent dusting and

        Dry fly ash should be transported in
        covered or pneumatic tanker trucks.

        Wind erosion of coal ash should be
        mitigated in highway construction application by moistening the ash during
        the construction phase or by using the material in slurry form.

        Coal ash used in road construction should be compacted and covered to
        minimize dusting.
    Workers involved with dry ash handling, concrete grinding, or
    demolition activities can come in contact with fugitive dust con-
    taining coal ash. Health risks associated with the inhalation of
    these fugitive dusts in occupational settings can be limited by
    following Occupational Safety and Health Administration (OSHA)
    standards and practices. These standards and practices are
    applicable whether or not  coal ash is used in concrete. Workers
    should request Material Safety Data Sheets (MSDS) from  coal
    combustion product suppliers when  they are not sure of the
    proper precautions.

    In addition, workers can minimize inhalation through a number
    of actions:

    «J»  Cleaning work areas regularly by wet sweeping or vacuuming.

    *>  Wearing basic personal protection such  as safety goggles with side shields to pro-
        tect  the eyes from dust.


       »>  Wearing a suitable particulate respirator (i.e., approved for particulates by the
           National Institute for Occupational Safety and Health—NIOSH) to prevent particu-
           late inhalation.

       »>  Adding water to the ash to prevent fly ash from blowing during handling.

       <»  Using standard dust filters on vehicles and silos.

       »>  Using mechanical ventilation or extraction in areas where dust could escape into
           the work environment.

       <»  Using closed pumping systems for bulk deliveries.

       An EPRI study to determine potential health effects of workers in frequent contact
       with coal fly ash concluded  that routine operating activities did not produce hazardous
       exposures.10 In addition,  occupational health records for these types of workers do not
       show a higher incidence of  respiratory problems than those of power plant workers
       who do not work as closely with fly ash. In some occupational settings, however,

          Coal contains naturally occurring radioactive elements. After combustion, these ele-
          ments and their decay products can remain in coal  combustion ash. EPA has classified
          coal fly ash as a diffuse, naturally occurring radioactive material, which is EPA's most
          benign radioactive classification.
          Studies have shown that the level of radioactivity in coal combustion products is
          about the same as the  level found in surface rocks  and soil.* A long-term Tennessee
          Valley Authority study of a 42-acre  site that used more than 1 million  cubic yards of
          fly ash in  structural fill  indicated that ambient radon levels measured directly over
          the fly ash fill  were comparable to the levels
          measured in control areas  without fly ash.
          Studies have also shown that radon releas-
          es from concrete blocks manufactured
          using coal fly ash are well  below  EPA's
          radon action levels. "
             Electric Power Research Institute.
             U.S. Environmental Protection Agency.
             October 1998.
        ' Electric Power Research Institute. 1998.

     such as maintenance activities or in an accident, some power plant workers can be
     exposed to higher concentrations of fly ash particles. In these cases, potential health
     problems related to either the presence of particles in the lungs or to specific sub-
     stances in the ash (e.g., metals or quartz) can occur from direct inhalation of higher
     concentrations of coal fly ash.

     Another study11 reviewed the toxicity and health hazards of coal fly ash compared to
     coal mine dust, which is known to cause pneumoconiosis and emphysema.
     Researchers concluded that exposure to high concentrations of coal fly ash can cause
     chronic bronchitis and air flow obstruction—typical of the common effects seen after
     inhaling a variety of different types of dusts. However, the study found no evidence
     that coal fly ash can induce pneumoconiosis and emphysema. Exposures to high con-
     centrations of coal fly ash can be minimized or prevented by following the guidelines
     presented earlier in this section and by observing OSHA requirements regarding nui-
     sance dust.
Skin Contact
     Power plant workers and people involved in producing cement, concrete, or other ash-
     based products can have skin contact with coal fly ash. In highway applications, skin
     contact is likely limited to construction workers working with dry ash. When construc-
     tion is finished, the road bed and a  properly seeded soil cover will reduce any chance
     of skin contact. While most contact with coal ash can be controlled by proper han-
     dling and  construction safety practices,  if contact does occur, coal ash can cause skin
     irritation or contact dermatitis.
    Workers can minimize skin contact through a number of spe-
    cific actions:

    *>  Wearing gloves or applying a barrier hand cream.

    •I*  Wearing loose, comfortable clothing that protects the
        skin and washing work clothes regularly.

    *>  Washing any exposed skin thoroughly with mild soap and
        water prior to eating and at the end of work activities.

    Others exposed to coal ash should wash exposed skin with
    mild soap and water and launder soiled clothing.
      Borm, P.J.A., December 1997.

        • i)•?•)'-!PA supports and encourages the beneficial use of coal combustion products
       |S': Wv jn highway construction applications for several reasons. First, coal combus-
       "5M>.\!( a tjon products are a significant component of the U.S. solid waste stream. The
       United States produced over 121 million tons of this material in 2003. Second, coal
       combustion products can be benefi-
       cially used in highway applications
       instead of being land disposed. This
       beneficial use has many environ-
       mental benefits, including reduced
       energy consumption, greenhouse
       gases, need for additional landfill
       space, and raw material consump-
       tion. Third, using coal combustion products in highway construction applications does
       not result in environmental harm or human health problems if proper management
       practices are followed.
       EPA conducted two regulatory determinations on the management and use of coal
       combustion products, in 1993 and in 2000. As part of these regulatory determina-
       tions, EPA evaluated the following eight factors:

       *i" The source and volume of coal combustion products generated per year

       <- Current disposal practices.

       *i" Potential danger, if any, to human health or the environment from the disposal of
          coal combustion products.

       * Documented cases in which danger to human health or the environment has
          been proved.

       •5* Alternatives to current disposal methods.

       <• The costs  of such alternatives.

       •5* The impact of those alternatives on the use of natural resources.

                   '!*-"u       ll>-.  ,,::  rr-f<  •"
*> The current and potential utilization of coal combustion products.

In conducting these two regulatory determinations, EPA did not identify any environ-
mental harm associated with the beneficial use of coal combustion products in high-
way construction applications and concluded in both determinations that these
materials did not warrant regulation as a hazardous waste. The beneficial use of coal
combustion products can include both encapsu-
lated and unencapsulated applications. EPA rec-
ognizes that unencapsulated uses of coal com-
bustion product require proper hydrogeologic
evaluation to ensure adequate groundwater

The 2000 regulatory determination recommend-
ed a  separate review addressing the use of coal
combustion wastes as fill for surface or under-
ground mines, which is currently underway.
EPA also has provided guidelines to the federal government for purchasing cement
and concrete products containing fly ash.12 In 1983, EPA promulgated the first fed-
eral procurement guideline that required agencies using federal funds to implement
a preference program favoring the purchase of cement and concrete containing fly
ash.  EPA also endorses the use of pozzolans, such as coal ash, as the preferred
method for stabilizing certain metal-bearing wastes. EPA published a summary of
information pertaining to coal combustion products use in an environmental fact
sheet, Guideline  for Purchasing Cement and Concrete Containing Fly Ash (EPA530-
SW-91-086, January 1992).

In addition, Executive Order 12873, Federal Acquisition, Hecycling, and Waste
Prevention, signed on October 20,1993, directs federal agencies to develop affir-
mative procurement programs for environmentally preferable products.  It also
requires EPA to issue guidance on principles that agencies should follow in making
determinations for the preference and purchase of these products.  In 1995, EPA
issued the Comprehensive Procurement Guideline, designating items that can be
made with recovered materials, including  coal fly  ash. EPA also further clarified
that flowable fill  from the combustion of coal can  be used  as a recovered material.
12 U.S. Environmental Protection Agency. January 28, 1983.


                   '•<  :.. '.If, III
               jhe following case studies provide examples of how coal combustion
         "tags)-' ........           °             I-           i-
          jjjjjjjjjjjj   products have been used successfully in a variety of highway construc-
          ts   tion applications nationwide over the past few decades.
  Cold In-Place Recycling of Asphalt Pavement, Jackson County, Missouri
       A Jackson County, Missouri innovative partnership rehabilitated 2.36 miles of deteri-
       orating rural roads, resulting in an environmentally sound and superior road surface at
       significant cost savings to the County.

                       The "Jackson County Partnership" included the County's Depart-
                       ment of Public Works,  Lafarge-North America, Kansas City Power &
                       Light and the University of Missouri-Kansas City (UMKC). The part-
                       nership developed a process in which the full depth of asphalt and
                       base material were pulverized and mixed with fly ash and water.
                       These constituents were re-compacted to form a strong, economi-
                       cal sub-base and then  covered with a new asphalt wear surface.

       In this project, an independent researcher and students from UMKC assisted in the
       development of County specifications and evaluated the finished product. The
       removal of the old asphalt and processing on site minimized the environmental
       impact of the project including use of nearly 1,700 tons of Class C fly ash donated by
       KCP&L and Lafarge-NA. The project to rehabilitate the road with fly ash cost about
       one-third less than it would have to remove and replace the entire road.  California
       Bearing Ratio values, a measurement of  strength, averaged 52 after 24 to 48 hours
       of curing. This stronger road base permitted a thinner  (less expensive) layer of
       asphalt to be applied as the final wear surface.

       On-site recycling of the old pulverized pavement with  locally provided fly ash,
                       reduced overall energy consumption, equipment and hauling costs
                       and emission pollution, as well as truck traffic. This project also
                       eliminated landfill  requirements, excavation, and depletion of
                       newly quarried rock and dredged sand. The partnership demon-
                       strates not only the value of innovative cooperation among organi-
                       zations, but also exemplifies the goals of the Coal  Combustion
                       Products Partnership.

                        Storrow Drive Connector
Boston Central Artery/Tunnel Project Massachusetts
    Approximately 3.8 million yards of concrete con-
    taining a 30 percent coal fly ash mix is being
    used in the sprawling Boston Central Artery/
    Tunnel project—one of the largest and most
    technologically challenging highway projects in
    the United States. Coal fly ash  is being used as
    part of the concrete design and specification
    because of its resistence to alkali reactivity and
    low heat of hydration. At the same time, the fly
    ash used in place of cement will prevent approx-
    imately 335,000 tons of greenhouse gases from
    being released.

    The project has two major components:

    1.  The replacement of a six-lane elevated highway with an eight- to 10-lane under-
        ground expressway directly beneath the existing road, culminating in a two-
        bridge crossing of the Charles River (the Cable Stayed  Bridge and the Storrow
        Drive Connector).

    2.  The extension of I-90 (the Massachusetts Turnpike) from its current terminus
        south of downtown Boston through a tunnel beneath South Boston and Boston
        Harbor to Logan Airport. The first link in this new connection—the four-lane Ted
        Williams Tunnel under the harbor—was finished in December 1995.
                  The concrete mixes used on the project
                  were designed to meet rigid project spec-
                  ifications. Using these mix-designs allows
                  for the elimination of construction joints,
                  which in turn helps the construction
                  schedule, saves on labor-intensive costs,
                  and allows for very large placements—up
                  to 1,400 cubic yards in a single pour.
Ted Williams Tunnel


  State Route 22 Project Georgia
       Post-construction environmental and performance testing determined that using
       coal fly ash as a base course along part of Georgia State Route 22 has resulted in
       negligible environmental impacts and has shown sustainable high performance.

       This test project was a joint venture of the Georgia Department of Transportation
       (GDOT), Southern Company Services, and the Georgia Power Company, with fund-
       ing from the Electric Power Research Institute,
       which promotes ash utilization in large volume
       applications. The testing area was constructed
       along a two-lane bypass section of Route 22,
       near Crawfordville, Georgia, approximately 90
       miles east of Atlanta.  Both coarse and fine ash
       were used to compare with  the typical con-
       struction materials replaced  by fly ash. Site preparations began in fall 1984, and
       construction of the ash layers was completed in July 1985.

       Class F fly ash supplied from Southern Electric System was used in three applica-
       tions: 1) a lime-fly ash (LEA) stabilized sub-base, 2) a  cement-stabilized fly ash
       (CFA) base course, and 3) a  cement stabilized pond ash (CPA) base course, each
       of which were each placed  in 1,000-foot-long test sections.

       Post-construction monitoring evaluated strength, road surface conditions, pavement
       deflections, groundwater quality from four groundwater monitoring wells and multi-
       ple leachate collection pipes, and environmental  effects resulting from the use of fly
       ash. Results indicate that the performance of all  test sections surpassed that of the
       control  section and exceeded GDOT requirements.  Environmental monitoring results
       indicate that the environmental impact of the test sections has been negligible.
  Route 213/301 Overpass Project Maryland
       Sixty thousand tons of Class F fly ash from the Baltimore Gas and Electric and the
       Delmarva Power plant were provided to the Maryland State Highway
       Administration in 1993 and 1994 to create the highway embankments for the
       Route 213 overpass over Route 301  on Maryland's eastern shore. A study of the

                                                             Case  Studies
    overpass was initiated in March 1999 by the Maryland Department of Natural
    Resources Power Plant Research Program to assess groundwater quality impacts
    and promote the beneficial use of coal combustion products generated in
    Maryland. Groundwater data collected during May, June, and July of 1999 indicate
    that the leachate from the fly ash has had no discernable impact on the groundwa-
    ter quality at the site.

    The site embankments were constructed using a base layer of silty sand, with the
    placement of sandy clay berms to contain the sides of the fly ash, and placement
    and compaction  of fly ash in 8-inch lifts. The fly ash was moistened to about 20
    percent prior to compaction and covered with 2 feet of sandy clay. The portions
    beneath the road were covered with a stone base and asphalt pavement.

    The groundwater study for this site involved using lysimeters, monitoring wells,
    and soil moisture probes in and through the fly ash fill  on the shoulder of Route
    213. Samples were collected to provide infor-
    mation on the embankment material's physical
    and chemical properties and were used to
    assess the factors  impacting the attenuation of
    constituents. Pore and groundwater samples
    collected at  the site were analyzed for dissolved
    trace  elements, major cations  and anions, and
    alkalinity. Water quality results indicated elevat-
    ed concentrations of several trace elements and
    major ions in the fly ash pore water, indicating
    that leachate is forming within the fly ash fill. The data also indicate, however, that
    these constituents are being attenuated in underlying  soils and ground water
    beneath the embankments. The water quality data indicate that the use of fly ash
    for highway  embankments can adequately protect groundwater quality.
Access Ramp Project Delaware
    Nearly 10,000 tons of stockpiled fly ash from Delmarva  Power and Light Company's
    Edge Moor Station were used to construct the main access ramps for a new inter-
    change to Interstate 495 near Wilmington, Delaware. This project was conducted
    during June  1987 and, during the two-year monitoring period that followed, showed
    no significant environmental effects, but did show high  performance characteristics.

       Environmental analysts studied the short-term effects of the project on local
       groundwater quality by evaluating four monitoring wells and four permeate collec-
       tion drains, and by collecting and analyzing runoff and leachate in the vicinity of
       the ash fill area. In addition, monitoring of post-construction performance showed
       that in-place soil had the same characteristics as a well-compacted granular soil.
       Less than one-eighth of an inch of settlement was measured at each of the set-
       tlement plate locations, indicating that the fly ash fill performed as well as con-
       ventional materials.
  McGee Creek Aqueduct Pipe Bedding Project Oklahoma
       Not only did the use of fly ash allow the entire McGee Creek Aqueduct Pipe
       Bedding project to proceed on a faster schedule, but it also resulted in a 40 per-
       cent cost savings. The 1984 construction of this 16.6-mile aqueduct near Ferris,
       Oklahoma, by the U.S.  Bureau of Land Reclamation reused 8,000 tons of fly ash.
       This ash was used to make a flowable fly ash grout mix, which was used instead
       of compacted crushed  stone for the pipe bedding.

       The pipeline contractor selected flowable fly ash grout for bedding to increase the
       speed of bedding placement, reduce labor and equipment costs, and provide a
       more uniform bedding. The flowable grout mix contained 11 percent Class C fly
       ash by weight,  as well as sand,  water, and R-7 chemical retarder. The fly ash, sup-
       plied  by Oklahoma Gas and Electric Company, had self-cementing and flash-setting
       properties, and the chemical retarding agent was used to control the flash-setting

       The performance of both the fly ash grout and a Portland cement grout, which was
       also used on the project, was compared by visual inspection. The fly ash grout
       exhibited the least amount of segregation, bleeding, and shrinkage. The fly ash
       grout also set up in the trench faster than the cement grout, allowing the second
       lift to be placed sooner and the entire operation to proceed more quickly than if
       conventional cement grout had been used. The material cost analysis indicated
       that the use of  Class C fly ash and retarder in place of Portland cement resulted in
       the significant cost savings. In addition, the use of  the fly ash grout for this project
       resulted in a reduced need for crushed stone.


American Coal Ash Association. 1998.  Innovative Applications of Coal Combustion
Products (CCPs).

American Coal Ash Association. 2002.  Annual Survey of Coal Combustion Products
Production and Use.

American Coal Ash Association. 2003.  Annual Survey of Coal Combustion Products
Production and Use.

American Coal Ash Association. 2004.  Annual Survey of Coal Combustion Products
Production and Use.

ASTM C 618-03.  (Also, AASHTO M 295). Standard Specification for Coal Fly Ash
and Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture in Concrete.

ASTM E 2277-03. Standard Guide for Design and Construction of Coal Ash in
Structural Fills.

Borm, PJ.A.  December 1997. Toxicity and Occupational Health  Hazards of Coal Fly
Ash. A Review of Data and Comparison to Coal Mine Dust. Annals of Occupational
Hygiene, Vol. 41,  No. 6, 659-676.

Department of Energy. July 1994. Barriers to the Increased Utilization of Coal
Combustion/Desulfurization Byproducts by Governmental and Commercial Sectors.
Office of Fossil Energy.

Department of Energy/Energy Information Administration. 1998. 1997 Annual
Energy Review, Appendix A. Washington  DC.

Electric Power Research Institute (EPRI). May 1990. Environmental Performance
Assessment of Coal Ash Use Sites: Little Canada Structural Ash Fill, EPRI Report
No. EN-6532.  Palo Alto, CA.

Electric Power Research Institute (EPRI). December 1990. Environmental
Performance Assessment of Coal Ash Use Sites: Waukegan Ash Embankment,
EPRI Report No. EN-6533.  Palo Alto, CA.

                 ; >•'•       MI
       Electric Power Research Institute (EPRI). February 1991. Use of Coal Ash in
       Highway Construction: Michigan Demonstration Project- Interim Report; EPRI GS-
       7175, Project 2422-7.

       Electric Power Research Institute (EPRI). August 1993. Fly Ash Exposure in Coal
       Fired Power Plants, EPRI TR-102576.

       Electric Power Research Institute (EPRI). November 1993.  Environmental
       Performance Assessments of Coal Ash Use Sites. EPRI Report No. RP-2796. Palo
       Alto, CA.

       Electric Power Research Institute (EPRI). June 1995. Environmental Performance
       Assessment of Coal Combustion Byproduct Use Sites; Road Construction
       Applications, EPRI TR-105127.

       Electric Power Research Institute (EPRI).  March 1998. High-Volume Fly Ash
       Utilization Projects in the United States and Canada, EPRI CS-4446, Second Edition,
       Project 2422-2.

       Electric Power Research Institute (EPRI). 1998. Coal Ash: Its Origin, Disposal, Use,
       and Potential Health Issues, EPRI Environmental Focus Issue Paper.

       Electric Power Research Institute (EPRI). 2002. Mercury Release from Coal Fly Ash.
       Palo Alto, CA. 1005259.

       Energy Information Administration. 2000. Voluntary Reporting of Greenhouse Gases
       2000, Report # DOE/EIA-0608.

       Federal  Highway Administration (FHWA). June 2003.  Fly Ash  Facts for Highway
       Engineers, FHWA-IF-03-019.

       Fly Ash  Resource Center. Fly Ash Material Safety Data Sheet.

       Hassett, David J., Debra F  Pflughoeft-Hassett, Dennis L. Laudal, and John H.
       Pavlish.  1999. Mercury Release from Coal Combustion Byproducts to the
       Environment, www.flyash.org/1999/ashpdf (then click on Hasset21.pdf)

       Hassett, David J., Loreal V Heebink. 2001. Release of Mercury Vapor from Coal
       Combustion Ash.  From the 2001 International Ash Utilization Symposium held
       October 22-24, 2001, Lexington, KY.


Heebink, Loreal V. and David J. Hassett. 2001. Coal Fly Ash Trace Element Mobility
in Soil Stabilization. From the 2001  Ash Utilization Symposium held October 22-24,
2001, Lexington, KY.

Kalyoncu, Rustu S. 2000. U.S. Geological Survey Minerals Yearbook—2000, Coal
Combustion Products.

Meij, Ruud and Henk te Winkel. 2001.  Health Aspects of Coal Fly Ash. From the
2001 Ash Utilization Symposium held October 22-24, 2001,  Lexington, KY.

Pflughoseft-Hassett, D.F, D.J. Hassett, and B.A. Dockter. 1993. High Volume Fly
Ash Utilization and the Effects on Groundwater in North Dakota in High-Volume
Uses/Concrete Applications. From Proceedings of the 10th International Ash Use
Symposium held January 18-21, 1993, Orlando, FL,. EPRI TR-101774, Project 3176,

Sutton, Michael E., Thomas  E. Schmaltz, Cheri Miller, and Kathy J. Harper. 2001.
Radon Emissions from a High Volume Coal Fly Ash Structural Fill Site. From the
2001 International Ash Utilization Symposium held October 22-24, 2001,
Lexington, KY.

U.S. Environmental  Protection Agency. January 28,1983. Guidelines for
Procurement of Products Containing Cement and Concrete, Federal Register
Notice. 48 FR 4230.

U.S. Environmental  Protection Agency. August 9,1993. Notice of Regulatory
Determination on Four Large-Volume Wastes from the Combustion of Coal by
Electric Utility Power Plants, Federal Register Notice. 58 FR 42466.

U.S. Environmental  Protection Agency. 1997. Annual Emissions and Fuel
Consumption for an "Average" Passenger Car.

U.S. Environmental  Protection Agency. October 1998. Supplemental Report to
Congress on Remaining Wastes from Fossil Fuel Combustion—Technical
Background Document: Beneficial Use of Fossil Fuel Combustion (FCC) Wastes.
Office of Solid Waste.

U.S. Environmental  Protection Agency. March 1999. Report to Congress: Wastes
from the Combustion of Fossil Fuels—Volume II,  EPA 530-S-99-010. Office of Solid

       U.S. Environmental Protection Agency. 2000. Municipal Solid Waste in the United
       States: 2000 Facts and Figures.

       U.S. Environmental Protection Agency. June 2002. Solid Waste Management and
       Greenhouse Gases, A Life-Cycle Assessment of Emissions and Sinks, Second
       Edition, EPA530-R-02-006. Office of Solid Waste.

       U.S. Environmental Protection Agency. February 2003. Guide for Industrial Waste
       Management, EPA 530-R-03-001. Office of Solid Waste.

U.S. Environmental Protection Agency, Coal Combustion Products Partnership
American Coal Ash Association
Utility Solid Waste Activities Group
Federal Highway Administration, Pavement Technology
Department of Energy
The Fly Ash Resource Center
Electric Power Research Institute (EPRI)
U.S. Environmental Protection Agency, Comprehensive Procurement Guidelines,
Cement and Concrete Specifications
University of New Hampshire, Recycled Materials Research Center
EERC/University of North Dakota, Coal Ash Resource Center
UWMilwaukee, Center for By-Products Utilization
Center for Applied Energy Research at the University of Kentucky
Ohio State University, Coal Combustion Product Extension Program
West Virginia University, Combustion Byproduts Recycling Consortium