Document Display | NSCEP | US EPA
The United States Environmental Protection Agency, as we've noted in a couple of previous reports, such as, for one example:
West Virginia Coal Association | US EPA Confirms Environmental Benefits of Coal Ash Utilization | Research & Development; concerning: "Study on Increasing the Usage of Recovered Mineral Components in Federally Funded Projects Involving Procurement of Cement or Concrete; United States Environmental Protection Agency in conjunction with the U.S. Department of Transportation and the U.S. Department of Energy; Report to Congress; June 3, 2008; EPA530-R-08-007; The most common beneficial use of coal fly ash is as a Supplementary Cementitious Material (SCM) in concrete. Coal fly ash is also used as a raw material in the production of cement clinker and as an additive to blended cements. The consistency and abundance of coal fly ash in many areas present unique opportunities for use in many construction applications, including pavements and highway and transportation structures, and can generate environmental benefits when used as a replacement for virgin materials (e.g., portland cement). 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";
actually has a history of promoting and encouraging the productive use of Coal-fired power plant Ash.
Their above report, you'll notice, was published by the US EPA in conjunction with The US Department of Transportation, who, through the offices of their Federal Highways Administration, the FHWA, as we documented for one instance in:
concerning: "'Fly Ash Facts for Highway Engineers'; American Coal Ash Association; DTFH61-02-X-00044; (for the) Federal Highway Administration; Report Number: FHWA-IF-03-019; June 13, 2003; Fly ash utilization, especially in concrete, has significant environmental benefits including: (1) increasing the life of concrete roads and structures by improving concrete durability; (2) net reduction in energy use and greenhouse gas and other adverse air emissions when fly ash is used to replace or displace manufactured cement; (3) reduction in amount of coal combustion products that must be disposed in landfills, and: (4) conservation of other natural resources and materials. Coal fly ash is a coal combustion product that has numerous applications in highway construction. This document provides basic technical information about the various uses of fly ash in highway construction";
have separately established and recorded the many, beneficial and performance-enhancing, ways Coal Ash can be utilized in highway construction projects.
Herein, we submit to you the US EPA's own take on the above "Fly Ash Facts for Highway Engineers", wherein, as you will see, they do flat-out recommend an increased use of Coal Ash in road construction.
One cautionary note: The initial link in this dispatch might well fail to function properly. The EPA's electronic library access system, from our point of view, leaves a bit to be desired.
That said, here is a search-engine link, which, if it remains durable, will take you to it.
Using Coal Ash in Highway Construction: A Guide to Benefits ... .
Should that link fail, here is the web address, which, when pasted into our browser, takes us to the document:
nepis.epa.gov/Exe/ZyPURL.cgi?
Failing all of that, we have downloaded a copy of the file, and will be separately transmitting a copy of it to the West Virginia Coal Association.
Brief comment follows excerpts from:
"'Using Coal Ash in Highway Construction; A Guide to Benefits and Impacts'; EPA-530-K-05-002; 2005.
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 concrete
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.
(We've previously documented all of the above for you. It's all easily verifiable, although the use of Coal Ash in cement and concrete, in the US, actually predated the 1942 work at Hoover Dam.)
In Washington, DC, both the metropolitan area subway system (Metro) and the new Ronald Reagan Building and International Trade Center were built with concrete containing coal fly ash.
(The Reagan Building is home to US EPA headquarters. See:
West Virginia Coal Association | US EPA Headquarters Housed in Coal Ash | Research & Development; wherein we're told, in part, that: "fly ash has been used in concrete since the 1930’s. Most notably, it has been used in several construction projects and prominent buildings, including the Ronald Reagan Government Office building, home to the Environmental Protection Agency (EPA) in Washington").
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.
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, flowable fill, and other beneficial 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 evaluation of local hydrogeological conditions ... .
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.
(All well and good, except that, as seen in:
Coal Combustion Products Partnership | Partnerships | US EPA; "EPA has suspended active participation in the Coal Combustion Products Partnership program while we are taking and assessing comment on the beneficial use of coal combustion residuals (CCR) through the CCR proposed rulemaking. While the Agency continues to support safe and protective beneficial reuse of coal combustion residues, the C2P2 program webpages have been removed while the program is being re-evaluated";
somebody must of got to 'em.)
When coal is burned in a power plant to generate electricity, it leaves behind residues that can be used as products or raw materials, primarily in the construction industry. These materials are known as coal combustion products, or CCPs. Power plants generate a variety of CCPs, namely bottom ash, fly ash, boiler slag, and flue gas desulfurization (FGD) materials. EPA and The concentrations of naturally occurring elements found in many industry refer to the larger ash particles fly ashes are similar to those that fall to the bottom of a furnace as found in naturally occurring soil. 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.
The two types of coal combustion products used most often in highway construction 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.
The two types of coal combustion products used most often in highway construction 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.
(As we've many times documented, but as the EPA fails herein to adequately address, as seen in:
West Virginia Coal Association | Pittsburgh Converts Coal Ash and Flue Gas into Cement | Research & Development; concerning: "United States Patent 5,766,339 - Producing Cement from a Flue Gas Desulfurization Waste; 1998; Dravo Lime Company, Pittsburgh; Cement is produced by forming a moist mixture of a flue gas desulfurization process waste product containing 80-95 percent by weight calcium sulfite hemihydrate and 5-20 percent by weight calcium sulfate hemihydrate, aluminum, iron, silica and carbon, agglomerating the moist mixture while drying the same to form a feedstock, and calcining the dry agglomerated feedstock in a rotary kiln (and) wherein said source of aluminum and iron comprises fly ash";
Coal Ash can also serve as the raw material from which the Cement is made, in addition to being an additive in, or simply a partial "replacement" for Portland Cement.)
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 generators generated more than 1.4 million tons of coal ash and boiler slag and beneficially used more than 1.1 million tons (81 percent). 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 beneficially used.
(We've made quite a few reports documenting Wisconsin's enlightened and assertive stance on the utilization of Coal Combustion Byproducts, as, for one instance, in:
West Virginia Coal Association | Wisconsin Coal Ash Utilization Guidebook Available | Research & Development; concerning: "'Coal Combustion Products Utilization Handbook' (2nd Edition); By Bruce Ramme & Mathew Tharaniyil (We Energies; aka Wisconsin Electric Power); Copyright 2004".
As we'll be documenting in reports to follow, some accounts have it that 100% of the Coal Ash generated in Wisconsin is productively utilized; while other accounts, though favorable, aren't quite as definitive.)
A New Era of Pavement Technology: Over the past 15 years, the Federal Highway Administration (FHWA) and its partners in state highway agencies, universities, and the pavement industry have achieved tremendous advances in pavement technology. The FHWA’s Office of Pavement Technology has been focusing on combining recent technical advances to develop long-life pavement 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.
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 conserves 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 concrete are more durable than those made without it and, therefore, do not need to be repaired and replaced as often."
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We're going to close our excerpts right there - - although the EPA does provide quite a lot more valuable insight into the use of Coal Ash in road construction applications - - since, in the above passage, the EPA specifically identifies Coal Ash for what it truly is: "a valuable resource", which they obviously hope their work "prevents the disposal of".
And, they have stuck commendably to that thesis, since, as seen our above-cited and linked report concerning: "'Study on Increasing the Usage of Recovered Mineral Components in Federally Funded Projects Involving Procurement of Cement or Concrete; Report to Congress'; June 3, 2008; EPA530-R-08-007; Use of coal combustion fly ash in concrete results in environmental benefits from avoided virgin materials extraction and manufacturing of portland cement. These benefits include reduced energy use and associated GHG emissions, reduced water use and reduced air pollution";
three years after issuance of our subject, "'Using Coal Ash in Highway Construction; A Guide to Benefits and Impacts'; EPA-530-K-05-002; 2005", the US EPA was still singing the same tune, that Coal Ash is a valuable resource, in an official report to the United States Congress.