KRC Supplements Testimony On Need To Better Control "Beneficial Reuse" of Coal Combustion Wastes And For Federal Regulatory Framework For Managing Coal Combustion Ash Posted: April 1, 2009
April 1, 2009
Ms. Marcie Cooperman, Clerk
Subcommittee on Energy and Mineral Resources
Committee on Natural Resources
U.S. House of Representatives
Washington, D.C. 20515
Re: Questions Concerning H.R. 493
Thank you for the additional time in which to respond to the questions posed by Representative John Sarbanes regarding coal ash regulation and beneficial reuse of coal combustion wastes.
Congressman Sarbanes posed three questions, and I will respond to each in turn:
1. Currently coal ash is beneficially used in concrete manufacturing, building materials, roadway embankments, development projects, and certain agricultural applications. What specific federal policies would you recommend to expand the current beneficial reuse of coal ash?
There are a number of legitimate beneficial uses for coal combustion ash, including those mentioned specifically in Congressman Sarbanes? question. There have also been, due to the absence of an effective and uniform national regulatory framework for management of the various coal combustion wastestreams (including fly and bottom ash), numerous instances in which beneficial reuses have undermanaged the coal combustion wastes relative to their potential environmental risks, and where activity more in the nature of disposal has been mischaracterized as beneficial reuse in order to avoid more rigorous disposal obligations.
One dubious beneficial reuse is the backhauling and land disposal of coal combustion ash in mine works. Coal combustion wastes are being backhauled and disposed, or beneficially reused, in mine workings (including both underground mine voids and more commonly, in surface mine backfills or spoil/mine waste fills) not because of the inherently beneficial or desirable attributes of the wastes relative to other backfill materials, or the lack of alternative locations available to utilities and non-utility customers for coal combustion waste disposal. Rather, such use and disposal is occurring because the coal companies offer the backhauling and disposal as a "service" or incentive in order to attract buyers for their coal in an increasingly competitive marketplace. Absent federal intervention to establish appropriate regulatory benchmarks for characterization and management of the wastes based on their intended end use or disposal, the competitive forces of the electric utility marketplace will continue to result in a parochial failure of the individual states to effectively control the disposal of CCW, and will increase pressure on coal companies to remain "competitive" with each other, and with other coalfields across the nation, by offering the ultimate "out of sight, out of mind" solution to the generation of the coal combustion waste indiscriminate blending in mine backfill.
What is known concerning the potential toxicity of the leachate from coal combustion ash suggests that a general federal floor of management standards is needed. As improvements continue to be achieved in both pre- and post-combustion scrubbing and capture of particulates and metals, we will of necessity change the composition and increase the potential toxicity of the wastes and leachate.
The proper management of CCW is essential for protection of human health and the environment. Adequate and comprehensive safeguards will prevent trafficking in environmental contamination by removing the incentive for those more interested in currying market share and short-term economic gain rather than the long-term public interest to undermanage the wastes.
There is good reason to insist that prior to approving coal combustion wastes for beneficial reuse, that appropriate characterization of the wastes be conducted for both short- and long-term leaching potential. These wastes contain a number of constituents of potential environmental and public health concern.
According to the EPA Report Wastes from the Combustion of Coal by Electric Utility Power Plants, EPA/530-SW-88-002:
The primary concern regarding the disposal of wastes from coal-fired power plants is the potential for waste leachate to cause ground-water contamination. Although most of the materials found in these wastes do not cause much concern (for example, over 95 percent of ash is composed of oxides of silicon, aluminum, iron and calcium), small quantities of other constituents that could potentially damage human health and the environment may also be present.
These constituents include arsenic, barium, cadmium, chromium, lead, mercury and selenium. At certain concentrations these elements have toxic effects.
Id., at ES-4.
While the findings of the EPA Report and review of industry-generated studies indicated generally that metals did not leach out of coal combustion waste (CCW) at hazardous levels, hazardous levels of cadmium and arsenic were found in ash and sludge samples, and boiler cleaning wastes sometimes contained hazardous levels of chromium and lead. Id.
While acknowledging that coal combustion wastes (fly ash and scrubber sludge) do not usually exhibit sufficiently high toxic properties to be classified as "hazardous" based on TCLP toxicity (meaning they don't leach metals at 100x safe drinking water levels), CCW does contain high enough concentrations of leachable toxic elements to create significant environmental concern. Boulding, J. Russell, Disposal of Coal Combustion Waste in Indiana: An Analysis of Technical and Regulatory Issues (1991).
Among the significant findings of this report, based on extensive literature review and analysis of coals burned in Indiana utilities (including Kentucky coals), are that:
1. Neither EP [toxicity] nor TCLP tests provide a good indication of leachability of CCW in natural disposal settings. Long-term leaching tests conducted until equilibrium has been achieved for each element of concern, using a leaching solution that approximated percolating groundwater, would give a more accurate depiction of ground-water contamination potential at a disposal site.
2. 17 potentially toxic elements are commonly present in CCW: aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, chromium, copper, lead, manganese, mercury, molybdenum, nickel, selenium, vanadium, and zinc.
3. Fluidized bed combustion (FBC) wastes retain volatile and semi-volatile elements in the bottom ash to a greater extent than conventional pulverized coal combustion, thus enhancing the leachability of FBC waste elements.
4. Leachates from coal power plant ash and flue gas desulfurization wastes typically exceed drinking water standards, but by a factor less than hazardous levels (i.e. 100 x DWS). The major leaching studies on CCW indicate that drinking water standards are typically exceeded by CCW ash leachate at a factor of 1.1 to 10, and often by a factor greater than 10 for one or more elements.
The EPA Report and Boulding study indicate that the management of CCW must be attuned to the variability of the concentrations of potentially toxic elements in the waste, and to the different problems presented by disposal sites, and by the type of special waste (i.e. FBC v. non-FBC wastes).
While the EPA Report concluded that CCW need not be regulated under RCRA Subpart C as hazardous, but rather that the wastes should continue to be regulated under Subpart D as solid wastes. In so recommending, EPA determined that while field observations detected off-site migration of potentially hazardous constituents from utility waste disposal sites, reflecting a potentially larger problem than laboratory analyses would suggest, the use of mitigative measures under Subpart D such as installation of liners, leachate collection systems, and ground-water monitoring systems and corrective action to clean up ground-water contamination, would be adequate for protecting public health and the environment. The EPA recommendation was predicated on the application of such measures to the management of CCW. Id. at ES 4-5.
Unfortunately, such measures are not employed in these situations where the ash is given to another entity for "beneficial reuse" and is disposed of as fill.
Prior to land application of the waste ash, any potential for leaching or other environmental release (including dermal or airway exposure to metals sorbed to the ash) must be thoroughly considered and the material must be determined appropriate for the intended use both in the short and the long-term. The testing that most states employ is a short-term dilute acid test known as TCLP testing, and is not appropriate for most beneficial reuse scenarios.
The literature summarized below reflects clearly that TCLP testing is insufficient to predict short-and long-term leaching characteristics of coal combustion fly and bottom ash used as fill. The use of short-term batch leaching tests, such as TCLP, EP-Toxicity, SPLP, and ASTM-D2987 (Shake Extraction) are not necessarily reflective of field conditions and long-term leaching potential. According to Ann Kim of the National Energy Technology Laboratory, [t]he utilization of coal combustion by-products (CCB) as bulk fill and mine backfill has raised questions about the potential contamination of surface and groundwater. . . . Leaching is related to the solubility of a specific compound and can be influenced by pH, temperature, complexation, and oxidation/reduction potential. . . . Regulatory tests and standard methods are not necessarily appropriate for leaching tests intended to stimulate natural processes.
Kim, CCB Leaching Summary: Survey of Methods and Results.
The TCLP test method is a batch test developed by EPA in response to deficiencies in an earlier test, the Extraction Procedure (EP). The test "was designed as a screening test to consider conditions that may be present in a municipal solid waste (MSW) landfill. It is acetic acid buffered to pH 5 (initial); 20: 1 liquid/solid ratio; particle size reduction to 9.5 mm; equilibrium. The reason it was designed this way was because, under RCRA, EPA is required to regulate as hazardous all wastes that may pose a hazard to human health and the environment if they are mismanaged. . . . co-disposal of industrial solid waste with MSW is considered to be a plausible worst-case management of unregulated waste."
Helms, US EPA Leach Testing of Coal Combustion Residues.
As Gregory Helms with the EPA Office of Solid Waste explained, the EPA Science Advisory Board commented on the TCLP test method in 1991 and again in 1999, expressing concern about overbroad use of the TCLP test. Id. The SAB found that TCLP is a screening test that evaluates leaching potential under a single set of environmental conditions. The SAB has expressed concern over the use of the TCLP when it has been applied to determine the leaching potential of wastes in disposal settings other than municipal waste co-disposal has been criticized.
The U.S. EPA utilized a new multi-tiered testing framework in a research program designed to evaluate the potential for mercury release from various types of coal combustion wastes. The alternative framework evaluates the potential leaching of waste constituents over a range of values for parameters that affect the leaching potential. In explaining the EPA decision to utilize a leach testing approach developed by Kosson et al. at Vanderbilt in evaluating leaching from coal combustion residues resulting from mercury emissions controls, Helms explained that TCLP wasnt used for evaluating coal combustion residues from enhanced mercury controls because TCLP is not technically appropriate where the disposal is not co-disposal with MSW.
Other commentators have noted the limitations of the use of TCLP as an analytical method for predicting leaching potential of coal combustion wastes. Hassett notes that
"The TCLP is often used in a generic manner for the prediction of leaching trends of wastes, although the intent of this test was for the prediction of leaching under co-disposal conditions in sanitary landfills. The application of acidic conditions to predict field leaching that can occur under a wide range of conditions may lead to false prediction of leaching trends. Additionally, conditions imposed on leaching systems by inappropriate leaching solutions may alter the distribution of redox species that would be found in the field and, in some cases with reactive wastes, 18 hours, as specified in the TCLP and other short-term leaching tests, may be an insufficient equilibration time. In order for a batch leaching test to be used, in determining potential for environmental impact . . . when being used with CCBs, the test must take into account the unique properties of the material, especially the hydration reactions of alkaline CCBs."
Hassett and Pflughoeft-Hassett, Evaluating Coal Combustion By-Products (CCBs) For Environmental Performance.
Because the tests are not designed for use with CCBs, they do not account for several typical reactions in CCBs under hydration. It has long been known that laboratory leaching procedures cannot precisely simulate field conditions nor predict field leachate concentrations. However, with careful application of scientifically valid laboratory procedures, it is possible to improve laboratory-field correlations and modeling efforts focused on predicting leachate concentrations. Id.
Hassett recommends the development of a selection of laboratory leaching procedures that more closely simulate field management scenarios, focusing specifically on technical and scientific variables such as the long-term hydration reactions that can impact leachate concentrations of several constituents of interest, the means by which water contacts the CCB in order to simulate the reduced permeability frequently exhibited in CCB utilization applications, the impact of pH and other CCB properties on the leachate and on resulting leaching; and the prediction of, and changes in, leaching over time. Id. Hassett recommends use of Synthetic Groundwater Leaching Procedure with a long-term leaching (LTL) procedure as a better predictor of leaching under field conditions. His work reflects that [I]n many applications, the extended-time SGLP has demonstrated trends significantly different from TCLP and other commonly used leaching protocols.
The explanation for the differing results and trends between the extended-time SGLP and TCLP can be explained by the fact that many commonly used leaching tests impose conditions different from those in a field environment on samples, and, thus, bias data in a manner leading to inappropriate interpretation for environmental impact. Elements most often affected include arsenic, boron, chromium, vanadium, and selenium. Id.
The EPA Report on Characterization of Mercury-Enriched Coal Combustion residues from Electric Utilities Using Enhanced Sorbents for Mercury Control, EPA/600/R-06/008 (January 2006) further underscores both the importance of utilizing proper test methods for characterization of these coal combustion wastes, and the trend towards increasing potential toxicity of such wastes as air pollution controls better capture metals entrained in and released during combustion of the coal. Among the observations of the agency were that arsenic and selenium may be leached at levels of potential concern from CCRs generated at some facilities both with and without enhanced mercury control technology [and that] further evaluation of leaching or arsenic and selenium from CCRs that considers site specific conditions is warranted.
With respect to the sufficiency of TCLP, EPA noted that leaching tests focused on a single extraction condition would not have allowed for an evaluation of the variations in anticipated leaching behavior under the anticipated field disposal conditions.
Reliance on total and TCLP data rather than on laboratory data that more accurately and adequately characterizes the leaching potential and nonhazardous nature of the wastes over the long-term, places both the utility and the regulatory agencies in a position where they cannot demonstrate with any degree of confidence that the use of these CCBs will not leach constituents of concern at levels of both regulatory and environmental concern. As part of any regulatory framework to review and approve beneficial reuses of coal combustion wastes, the EPA should direct that testing appropriate to the intended end-uses be performed. Dynamic testing under a range of conditions will better predict the long-term leaching potential of these coal combustion wastes when used as fill in conditions where they are not isolated from surface or groundwater infiltration.
Returning to the question, in short, the adoption of a program of uniform, comprehensive and appropriate minimum standards for the characterization and management of coal combustion wastes both for reuse and disposal is the best way to improve the beneficial utilization of CCW by weeding out ill-conceived and underprotective reuse proposals, and sham reuses that are in the nature of disposal.
2. Are you aware of any downside in the beneficial reuse of coal ash such as runoff, leaching or diminished structural integrity of the building materials?
The beneficial reuse situations of which I am aware include a range of uses. In those cases where the materials are incorporated into a fixed matrix and become part of a product, such as the use of ash in Portland Cement manufacture, the interest of the manufacturer in assuring that the blending of ash into the produce will not compromise the functional or structural integrity of the material acts to constrain, to a certain extent, the negative impact of the material on structural integrity or performance.
Of greater ecological concern in my experience has been the use of coal ash (particularly fly ash) as fill or for backfilling utility trenches. In those instances, the unconsolidated or partially consolidated disposal of the material can allow groundwater or precipitation to leach metals out of the wastes at levels exceeding drinking water levels. Numerous instances of groundwater and surface water contamination associated with managed disposal have been documented, and there is no reason to believe that disposal in unlined fills or utility trenches would cause a different outcome in terms of the fate and transport of leached metals.
Documentation of specific instances of contamination associated with beneficial reuses is harder to come by, since one of the significant weaknesses in state-lead programs for beneficial reuse is that, while environmental performance standards for protection of surface or groundwaters is usually established, no advance testing is required, and no groundwater or surface water monitoring of the site of the reused material is required, so that compliance with the standards is not demonstrated and violations are not detected. As mentioned above, proper testing (appropriate to the disposal or reuse conditions) should be a cornerstone of any management framework.
3. EPA Administrator Jackson has said that she will move aggressively to regulate the disposal of coal combustion wastes. What do you think are the most important elements of a regulatory framework for the disposal of dry coal combustion waste products? How do you think those regulations should be structured?
KRC believes that any program developed by EPA should be developed under the Resource Conservation and Recovery Act and should include:
* Identification of and proper management and disposal of other fossil fuel-related wastes that may contain higher levels of toxic constituents, such as (1) fluidized bed combustion (FBC) wastes that may contain residual unburned organics not associated with typical coal ash. Greater scrutiny is warranted for FBC waste, which presents a higher potential for leaching elements of concern; (2) wastes generated through the firing of hazardous waste fuels and waste oils with or without coal; and (3) wastes fired or co-fired with waste tires and refuse-derived fuel. Each of these categories adds constituents to the combustion process which may increase the hazards of improper disposal of the waste, including a range of products of incomplete combustion of chlorinated and other synthetic organic compounds that warrant extensive analysis, characterization and careful management beyond that necessary for coal combustion waste.
* Clarification that coal combustion wastes do not include utility wastes such as metal and boiler cleaning wastes, nor other wastes generated from power plants beyond those directly resulting from combustion of coal and control of emissions from the combustion process.
* Screening of all coal combustion wastes for radionuclides and management as low-level radioactive wastes in accordance with the applicable state and federal laws, where those wastes exhibit activity that is above background levels. Coal combustion waste containing elevated radionuclides should be classified and managed as technologically enhanced low-level radioactive waste.
* Complete characterization of the waste stream(s) proposed for land disposal, and assurance that the engineering design of the disposal facility or proposed reuse scenario will assure compliance with the environmental performance standards (including no contamination of aquifers above drinking water standards and no increase in groundwater of any constituents above background levels of those contaminants). Whenever possible the chemical and physical composition of the actual waste stream that will be produced by the combustion process at the utility from which the waste will be generated, should be used for testing.
* In order to properly design a facility for disposal of coal combustion waste, or to demonstrate that reuse will not cause environmental harm, the leaching potential must be established by use of appropriate modeling of the disposal site, the amount of rainfall infiltration, the pH of the waste and associated materials through which the rainfall will pass, and a hydrogeologic investigation into the location, extent, and characteristics of the surface and groundwater systems at the site. As noted above, short-term TCLP testing is insufficient to characterize longer term leaching potential, and should not be used in any situation except where the coal combustion wastes are being co-disposed with mixed municipal waste in a Subtitle D landfill.
* Groundwater monitoring must be sufficient to allow for prompt detection of leachate migration at the waste site (and not the mine) boundary. Monitoring parameters and well locations must be such that they are appropriate to the area in which the waste is disposed.
* Blending of mine wastes containing fly ash with spoil in the mine backfill, rather than controlled placement of the wastes in a designed facility, should be treated as prohibited open dumping.
* A requirement for controlled placement in a discrete, properly engineered and lined land disposal facility with groundwater monitoring, leachate collection, closure and post-closure care, and financial responsibility. When EPA determined that issuance of regulations under Subtitle C of RCRA was not necessary to adequately manage the environmental risks associated with disposal of coal combustion wastes, it premised that determination on the assumption that the environmental performance standards and protections of Subtitle D would be extended to the management of that industrial waste stream.
* Financial responsibility sufficient to assure that proper closure and post-closure care is provided in the event of default by the facility owner and operator.
* The framework must be a regulatory framework rather than asset of guidelines. The lack of federal minimum standards has resulted in uneven state standards and under-regulation of the wastes. Kentucky, for example, has more rigorous standard for co-disposal of CCW in mines, but extremely weak controls on beneficial reuse and disposal in "ash ponds." The lack of federal minimum standards has and will continue to result in one-downsmanship and a "race to the bottom" among the coal states, as companies desirous of securing market share from the purchaser of the lion's share of their output, the utility industry, offer to backhaul and dispose of coal combustion wastes as a package deal.
Issuance of national guidance is insufficient to assure proper management of these wastes, since many states have "no more stringent" provisions that would prevent states from extending regulatory authority over disposal of the wastes to incorporate federal guidance, since states can adopt and impose only those standards that have been adopted by regulation at the federal level. Also, some states cannot under state law impose substantive requirements based on "policies."
Additionally, the lack of minimum standards penalizes utilities that manage wastes under higher standards relative to their brethren who allow disposal of coal wastes by the coal industry either for "beneficial" uses or as mine fill.
Finally, the lack of national regulatory standards sufficient to assure protection of land, air and water resources heightens conflicts between host communities and the utility and coal industry due to concerns with under-regulation of the coal combustion wastes relative to their potential to leach metals and other constituents at levels posing environmental or health risks.
I have attached a March 2, 2009 letter that outlines in more detail what I believe to be necessary components of an appropriate regulatory program for coal combustion wastes.
Thank you for the opportunity to address these issues, and for the hospitality extended me during the February 12, 2009 hearing. Lease let me know if you need further information.