LABORATORY METHODS FOR THE 

EVALUATION OF POTENTIAL RELEASE OF 

MERCURY FROM COAL UTILIZATION 

BY-PRODUCTS 

Topical Report 

Prepared for: 

Ms. Lynn Brickett 

U.S. Department of Energy 

National Energy Technology Laboratory 

626 Cochrans Mill Road 

PO Box 10940 MS 922-273C 

Pittsburgh, PA 15236-0940 

Other Industrial Sponsors 

Prepared by: 

Debra F. Pflughoeft-Hassett 

David J. Hassett 

Tera D. Buckley 

Loreal V. Heebink 

Erick Zacher 

Energy & Environmental Research Center 

University of North Dakota 

PO Box 9018 

Grand Forks, ND 58202-9018 

April 2005
EERC DISCLAIMER

LEGAL NOTICE This research report was prepared by the Energy & Environmental 

Research Center (EERC), an agency of the University of North Dakota, as an account of work 

sponsored by the U.S. Department of Energy, Center for Air Toxic Metals®, Cynergy, Utility 

Solid Waste Activities Group, North Dakota Industrial Commission, and Great River Energy. 

Because of the research nature of the work performed, neither the EERC nor any of its 

employees makes any warranty, express or implied, or assumes any legal liability or 

responsibility for the accuracy, completeness, or usefulness of any information, apparatus, 

product, or process disclosed, or represents that its use would not infringe privately owned rights. 

Reference herein to any specific commercial product, process, or service by trade name, 

trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement 

or recommendation by the EERC. 

DOE DISCLAIMER

 This report was prepared as an account of work sponsored by an agency of the United 

States Government. Neither the United States Government, nor any agency thereof, nor any of 

their employees makes any warranty, express or implied, or assumes any legal liability or 

responsibility for the accuracy, completeness, or usefulness of any information, apparatus, 

product, or process disclosed or represents that its use would not infringe privately owned rights. 

Reference herein to any specific commercial product, process, or service by trade name, 

trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, 

recommendation, or favoring by the United States Government or any agency thereof. The views 

and opinions of authors expressed herein do not necessarily state or reflect those of the United 

States Government or any agency thereof. 

ACKNOWLEDGMENT

 This report was prepared with the support of the U.S. Department of Energy (DOE) 

National Energy Technology Laboratory Cooperative Agreement No. DE-FC21-93MC30098. 

However, any opinions, findings, conclusions, or recommendations expressed herein are those of 

the authors(s) and do not necessarily reflect the views of DOE. 
i 

TABLE OF CONTENTS 

LIST OF FIGURES ........................................................................................................................ ii 

EXECUTIVE SUMMARY ...........................................................................................................iii

INTRODUCTION .......................................................................................................................... 1 

BACKGROUND ............................................................................................................................ 1 

OBJECTIVES................................................................................................................................. 3 

METHODOLOGIES – ANALYTICAL AND CHARACTERIZATION METHODS ................. 4 

 Chemical and Physical Characterization ............................................................................... 4 

 Total Mercury ............................................................................................................... 4 

 Total Air Toxic Elements.............................................................................................. 4 

 Total Bulk Chemical Composition ............................................................................... 4 

 LOI and Moisture.......................................................................................................... 5 

 pH.................................................................................................................................. 5 

 Carbon Forms................................................................................................................ 5 

 Eh .................................................................................................................................. 5 

 Method Used to Measure Mercury on Gold-Coated Quartz Traps........................................ 5 

 Method Used to Measure Mercury on Carbotraps................................................................. 6 

METHODS FOR THE EVALUATION OF THE RELEASE POTENTIAL OF MERCURY 

AND OTHER AIR TOXIC ELEMENTS FROM CUB................................................................. 6 

 Direct Leaching...................................................................................................................... 6 

 Vapor-Phase Transport .......................................................................................................... 8 

 Long-Term Ambient Temperature Release .................................................................. 8 

 Vapor-Phase Transport ........................................................................................................ 10 

 Thermal Desorption at Elevated Temperature............................................................ 10 

 Microbiologically Mediated Leaching and Vapor-Phase Transport.................................... 13 

SUMMARY.................................................................................................................................. 16 

REFERENCES ............................................................................................................................. 17 

DRAFT ASTM STANDARD METHOD FOR SYNTHETIC GROUNDWATER 

LEACHING PROCEDURE ..........................................................................................Appendix A 
ii 

LIST OF FIGURES 

1 Information from EPA on mercury emissions........................................................................ 2 

2 Long-term leaching results for boron ..................................................................................... 7 

3 Indirect evidence of ettringite formation using SGLP and LTL............................................. 8 

4 Mercury vapor release collection apparatus ........................................................................... 9 

5 Average total long-term ambient-temperature mercury release or sorption as related 

to blank values ...................................................................................................................... 10 

6 Mercury thermal desorption apparatus ................................................................................. 11 

7 Typical thermal desorption curve for fly ash........................................................................ 12 

8 Example of thermal desorption curve for an FGD material ................................................. 12 

9 Microbiologically mediated mercury vapor-phase collection apparatus utilizing a 

wrist action shaker to facilitate mixing................................................................................. 14 

10 Microbiologically mediated mercury vapor-phase collection apparatus utilizing a 

stir plate to facilitate mixing ................................................................................................. 14 

11 Example of a SPME chromatogram ..................................................................................... 15 
iii 

LABORATORY METHODS FOR THE EVALUATION OF POTENTIAL RELEASE OF 

MERCURY FROM COAL UTILIZATION BY-PRODUCTS 

EXECUTIVE SUMMARY 

 Under a 3-year effort funded by the U.S. Department of Energy (DOE) and industry 

entitled “Mercury and Air Toxic Element Impacts of Coal Combustion By-Product Disposal and 

Utilization,” the Energy & Environmental Research Center (EERC) is evaluating the impact of 

mercury and other air toxic elements on the management of coal utilization by-products (CUBs). 

The EERC is measuring the release of mercury and other air toxic elements under different 

controlled laboratory conditions and investigating the release of these same air toxic elements in 

select field settings. Results will be used to determine if mercury release from CUBs, both as 

currently produced and as produced with mercury and other emission controls in place, will 

potentially impact CUB management practices. In order to adequately address the potential for 

release of mercury from CUBs, sorbents, and combinations, release mechanisms that must be 

evaluated include 1) leaching, 2) elevated- and ambient-temperature vapor-phase releases, and 

3) microbiologically mediated releases. The EERC initiated research on the potential release of 

mercury from CUBs in 1999 and found that methodologies for evaluating the release of mercury 

from CUBs using these mechanisms were not documented in the scientific literature, with the 

exception of leaching. As a result, method development work was initiated under the U.S. 

Environmental Protection Agency (EPA) Center for Air Toxic Elements and the Coal Ash 

Resources Research Consortium. 

 The EERC concluded Year 2 of this effort in April 2005, and this report details the results 

to date from Task 2: Analytical Methods Selection. As noted in several forums in recent years, the 

methods used to evaluate CUBs must be relevant to the material and the management of CUBs 

where possible. EERC researchers reviewed methods currently being used at the EERC and 

elsewhere to determine the best possible methods for this effort. 

 Laboratory methods were selected based on early work performed at the EERC but method 

development and modification continued. The methods being employed to evaluate the release of 

mercury from CUBs by direct leaching, exposure to ambient and elevated temperatures, and 

exposure to biota are described, and method limitations are discussed. 
1 

LABORATORY METHODS FOR THE EVALUATION OF POTENTIAL RELEASE OF 

MERCURY FROM COAL UTILIZATION BY-PRODUCTS 

INTRODUCTION 

 The stability of mercury associated with coal utilization by-products (CUBs) has become a 

prominent question as the coal-fired utility industry develops and tests mercury emission controls 

that may consequently increase the mercury associated with CUBs. The reasons for evaluating 

the release of mercury from CUBs are 1) to determine if mercury captured on CUBs is stable or 

if it will be released, thus negating the purpose of the removal of the mercury from the 

emissions, and 2) to aid utilities in determining and understanding changes in CUBs associated 

with mercury control and associated CUB management. 

 Under a 3-year effort funded by the U.S. Department of Energy (DOE) and industry 

entitled “Mercury and Air Toxic Element Impacts of Coal Combustion By-Product Disposal and 

Utilization,” the Energy & Environmental Research Center (EERC) is evaluating the impact of 

mercury and other air toxic elements on the management of CUBs. The EERC is measuring the 

release of mercury and other air toxic elements under different controlled laboratory conditions 

and investigating the release of these same air toxic elements in select field settings. Results will 

be used to determine if mercury released from CUBs, both as currently produced and as 

produced with mercury and other emission controls in place, will impact CUB management 

practices. 

 The EERC concluded Year 2 of this effort in April 2005, and this report details the results 

to date from Task 2: Analytical Methods Selection. As noted in several forums in recent years, the 

methods used to evaluate CUBs must be relevant to the material and the management of CUBs 

where possible. EERC researchers reviewed methods currently being used at the EERC and 

elsewhere to determine the best possible methods for this effort. A summary of research in this 

area was published in 2004 (1). 

BACKGROUND 

 Recent projections from the Energy Information Administration indicate that U.S. demand 

for energy will increase from 97.3 quadrillion to 130.1 quadrillion Btu between 2001 and 2020, 

reflecting an annual growth rate of 1.5%. By 2025, total energy consumption is projected to 

reach 139.1 quadrillion Btu (2). Fossil fuel combustion, including the burning of coal, natural 

gas, or oil, provides about 85% of the present energy production in the United States. Of this 

amount, over 50% is provided by coal-fired utilities (2). As a result of energy production from 

coal, CUBs are generated, and CUBs, as produced in the United States, are primarily a result of 

emission control technologies installed to meet emission regulations. 

 Emission regulations first mandated reduction of particulate matter released to the 

atmosphere by utilities, which required utilities to install collection devices for generated fly ash. 

Later emission regulations significant to CUB production mandated limits on SOx emissions. As 
2 

a result, utilities using high-sulfur coal could change coal sources, resulting in a different 

by-product character, or scrub the flue gas using sorbents to remove the SOx gases. The result of 

flue gas desulfurization (FGD) was high volumes of spent FGD sorbent material. There is a wide 

range of FGD technologies, so FGD materials have broadly varied characteristics, but generally 

contain high concentrations of calcium and sulfur. Currently, utilities are responding to 

regulation placing limits on NOx emissions, which also impacts the character of ash by-products, 

including potentially increasing the amount of unburned carbon in fly ash or adding ammonia to 

the fly ash. Issues related to air toxic emissions, including mercury, are currently under technical 

and regulatory scrutiny. 

 Figure 1 includes an excerpt from a U.S. Environmental Protection Agency (EPA) Fact 

Sheet titled “EPA Proposes Options for Significantly Reducing Mercury Emissions from Electric 

Utilities,” in which some of the concerns about mercury are summarized. On December 14, 

2000, EPA announced that it would regulate mercury emissions from coal- and oil-fired electric 

utility steam-generating power plants (3); propose regulations by December 15, 2003; and 

finalize regulations by December 15, 2004. On December 15, 2003, EPA signed the Utility 

Mercury Reductions proposal, which seeks comments on two approaches for reducing mercury 

by up to nearly 70%. On March 15, 2005, the EPA issued the first federal rule to permanently 

cap and reduce mercury emissions from coal-fired power plants (a power plant is defined as an 

electrical generating facility that provides >25 MWe). The rule is a market-based cap-and-trade 

program (Section 111 of the Clean Air Act) and is similar to the program in place for SO2. The 

rule is to be administered in two phases. The first phase places a cap of 38 tons per year of 

mercury beginning in 2010. The second phase sets a final cap of 15 tons by 2018. Coal-fired 

power plants currently emit about 48 tons per year; therefore, the reduction in mercury emissions 

will be 21% and 69%, respectively. 

Figure 1. Information from EPA on mercury emissions (4). 

Mercury Emissions – Both Naturally Occurring and Man-made Sources

• Mercury is a toxic, persistent pollutant that accumulates in the food chain. Fossil fuel-fired utilities are 

the largest source of human-generated mercury emissions in the United States. 

• Concentrations of mercury in the air are usually low and of little direct concern. However, 

atmospheric mercury falls to Earth through rain or snow and enters lakes, rivers, and estuaries. Once 

there, it can transform to its most toxic form, methylmercury, and accumulate in fish and animal 

tissues. 

• Americans are exposed to mercury primarily by eating contaminated fish. Because the developing 

fetus is the most sensitive to the toxic effects of mercury, women of child-bearing age are regarded as 

the population of greatest concern. Children who are exposed to low concentrations of methylmercury 

prenatally are at increased risk of poor performance on neurobehavioral tasks, such as those measuring 

attention, fine motor function, language skills, visual-spatial abilities, and verbal memory. 

EXCERPTED FROM EPA FACT SHEET: 

EPA Proposes Options for Significantly Reducing 

Mercury Emissions from Electric Utilities 

December 15, 2003 
3 

The reduction of emissions at coal-fired power plants has historically impacted the 

quantity and character of resulting CUBs. The removal or reduction of mercury emissions at 

coal-fired power plants has high potential to do the same because several proposed mercury 

emission control technologies involve the use of solid sorbents that will likely be introduced in 

the flue gas and collected with the fly ash. Other candidate emission control technologies focus 

on increasing the mercury sorbed on FGD materials. These mercury emission control 

technologies will impact the mercury content of CUBs. The question that this project was 

designed to answer is, “Will the changes in CUBs associated with mercury emission controls 

change the management options for those CUBs as they relate to the potential release of 

mercury?” 

Since the large volumes of CUBs produced annually in the United States are managed 

either by disposal or utilization, the design of various tasks in this project focused on simulating 

potential behavior of CUBs in environments where they are typically managed. Examples of 

utilization scenarios include: 

• The use of fly ash in concrete, soil stabilization, or fills that could be exposed to natural 

waters or to microbial action. 

• The use of FGD gypsum in wallboard, where it may be exposed to high temperatures in 

production or to natural water under disposal. 

• The use of fly ash in cement clinker production, where it would be exposed to 

extremely high temperatures. 

• The use of FGD gypsum or fly ash as an agricultural soil amendment or mine fill, where 

it would be exposed to natural water and, potentially, microbial action. 

 In order to adequately address the potential for release of mercury from CUBs, sorbents, 

and combinations, release mechanisms that must be evaluated include leaching, elevated- and 

ambient-temperature vapor-phase releases, and microbiologically mediated releases. The EERC 

initiated research on the potential release of mercury from CUBs in 1999 and found that methods 

for evaluating the release of mercury from CUBs using these mechanisms were not documented 

in the scientific literature, with the exception of leaching. As a result, the EERC initiated a 

program under EPA’s Center for Air Toxic Metals® and the Coal Ash Resources Research 

Consortium® to develop laboratory methods that would provide information on the potential for 

CUBs to release mercury and other air toxic elements under conditions associated with the 

proposed release mechanisms of direct leaching, direct ambient- and elevated-temperature vaporphase release, and microbiologically mediated leaching and vapor-phase release. 

OBJECTIVES 

The goal of the methods selection task was to select or develop appropriate laboratory 

methods to evaluate the potential for release of mercury from CUBs under conditions that are 

relevant to management options applied to CUBs. Supporting objectives were as follows: 
4 

$ Select and apply one or more leaching procedures appropriate for environmental 

characterization of CUBs. 

$ Select, develop, and apply a method to evaluate the release of mercury through 

offgassing from CUBs at elevated temperatures. 

$ Select, develop, and apply a method to evaluate the release of mercury through 

offgassing from CUBs exposed to ambient temperature air. 

$ Select, develop, and apply a method to evaluate the release of mercury through leaching 

and offgassing from CUBs exposed to biota commonly found in natural settings. 

$ Select and apply laboratory analytical methods required to determine mercury in 

solutions, collected on analytical traps, and in solid materials. 

METHODOLOGIES – ANALYTICAL AND CHARACTERIZATION METHODS 

Chemical and Physical Characterization 

Chemical characterization of samples included total mercury and total bulk chemical 

composition on major, minor, and trace constituents. Physical characterization included carbon 

forms, pH, moisture, and loss-on-ignition (LOI) measurements. Eh measurements were taken on 

samples used for microbiological experiments. Methodologies used for these characterizations 

are further described below. 

Total Mercury 

The total mercury content of solid samples was determined using a direct mercury analyzer 

or digestion followed by cold-vapor atomic absorption spectrometry (CVAAS). 

Total Air Toxic Elements 

The total concentration of the other air toxic elements of arsenic, cadmium, chromium, 

lead, nickel, and selenium was determined using standard methods. Acid digestion was used on 

the CUB followed by detection using inductively coupled atomic emission spectroscopy (ICP–

AES) or ICP mass spectroscopy (ICP–MS). 

Total Bulk Chemical Composition 

 The major bulk composition, reported as percent oxides, was determined using x-ray 

fluorescence spectrometry. American Society for Testing and Materials (ASTM) D4326-04 

Standard Test Method for Major and Minor Elements in Coal and Coke Ash by X-Ray 

Fluorescence was used (5). 
5 

LOI and Moisture 

Standard characterization techniques were used to measure LOI and moisture content. 

ASTM C311-04 Standard Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans 

for Use in Portland-Cement Concrete was used (6). 

pH 

The pH of samples was determined using distilled water and/or 1 M KCl. The method 

employing 1 M KCl is required for many types of solid samples that exhibit a double electric 

layer that impacts the determination of pH. For this task, a slurry of 25 mL of 1 M KCl solution 

was mixed with 10 g of CUB, and the resulting pH was measured and recorded. As previously 

noted, the pH was also determined in slurry of distilled, deionized water. Where both methods 

were employed in this effort, it was noted that the pH values were similar. A comparison of these 

data for a relatively broad range of CUB types led researchers to conclude that it is not necessary 

to use 1 M KCl in determining the pH of CUB; therefore, remaining samples were evaluated 

using distilled, deionized water slurries. It is likely that the high concentration of total dissolved 

solids generated in the pH determination eliminated the double electric-layer effect that requires 

the use of KCl solution in the determination of pH in other types of solid samples. 

Carbon Forms 

Dominant carbon forms were identified in a select group of project samples. The samples 

on which carbon forms were determined were prepared by mounting them in epoxy resin. The 

sample was dispersed in the bottom of a 1-inch-diameter rubber cup mold. The epoxy was 

stained using Sudan black, which results in a high contrast between the particles of interest and 

the mounting medium. The surfaces to be analyzed were polished with incrementally smaller 

grits with 1⁄4 μm being the final polishing grit used. The samples were then examined using a 

reflected-light microscope.

Eh 

Eh was determined using a platinum electrode with a standard reference electrode. 

Method Used to Measure Mercury on Gold-Coated Quartz Traps 

Gold-coated quartz mercury collection traps were desorbed for analysis by heating to 

approximately 500°C, and the mass of mercury released was determined using double-gold 

amalgamation with atomic fluorescence (AF) detection. A Brooks Rand Model III cold-vapor 

atomic fluorescence spectrophotometer (CVAFS) was utilized for mercury concentration 

determination. 
6 

Method Used to Measure Mercury on Carbotraps 

Supelco CarbotrapTM collection traps were analyzed for total mercury by heating them to 

approximately 300°C, passing the released organomercury through a tube held at about 800°C, 

and collecting the mercury on a gold-coated quartz trap, which was analyzed as described above. 

METHODS FOR THE EVALUATION OF THE RELEASE POTENTIAL OF 

MERCURY AND OTHER AIR TOXIC ELEMENTS FROM CUB 

Direct Leaching 

 

 Leaching is the most likely mechanism of transport of constituents from disposed or 

utilized CUBs contacted by water. Leaching is typically performed on CUBs to characterize 

them for management purposes. The leaching tests performed on the samples in this project were 

the toxicity characteristic leaching procedure (TCLP [EPA Method 1311 (7)]), the synthetic 

groundwater leaching procedure (SGLP), and long-term leaching (LTL) with 30- and 60-day 

equilibration periods. 

TCLP is a leaching procedure designed for the evaluation of leaching of wastes when 

codisposed in a sanitary landfill. Leaching with TCLP utilizes a 20:1 liquid-to-solid ratio, endover-end agitation at approximately 30 rpm, an 18-hour equilibration time, and one of two 

extraction fluids. The extraction fluid used is dictated by the pH of the material being leached. 

Extraction Fluid 1, used when the pH is below 5, is prepared by adding glacial acetic acid and 

sodium hydroxide to reagent water, and has a fluid pH of 4.93 ± 0.05. Extraction Fluid 2, used 

when the pH of the material is above 5, is prepared by adding glacial acetic acid to reagent water, 

resulting in a fluid pH of 2.88 ± 0.05. 

 The SGLP batch-leaching procedure is a relatively simple test that follows many of the 

conditions of TCLP. The test utilizes a 20:1 liquid-to-solid ratio, end-over-end agitation at 

approximately 30 rpm, an 18-hour equilibration time, and usually employs a leaching solution 

consisting of water from the site, water that has been prepared in the lab similar to water likely to 

contact the CUB, or distilled deionized water. When distilled water is used as the leaching 

solution for SGLP, the method is equivalent to the ASTM D3987 Standard Test Method for 

Shake Extraction of Solid Waste with Water (8). Distilled deionized water was used in this 

effort. For the long-term component of this procedure, multiple bottles are set up and analyzed at 

different time intervals. A typical SGLP–LTL test might consist of 18-hour, 30-day, and 60-day 

equilibration times. Although 60 days is often not adequate to achieve complete equilibrium, it is 

generally long enough to determine the concentration evolution of individual parameters. The 

most important factor when performing LTL is to have at least three equilibration times to 

determine a true trend. A draft of the SGLP–LTL method prepared for consideration by ASTM is 

in Appendix A. 

 For all leaching procedures, the solids were filtered from the leaching solution through a 

0.45-μm filter, the pH of the resulting leachate was measured, and the leachate was preserved 

with HCl for mercury determination and with HNO3 for determination of other trace elements. 
7 

Mercury leachate concentrations were determined using CVAAS and CVAFS as noted in the 

analytical methods section. Other trace elements were determined using inductively coupled 

argon-plasma spectrometry, ICP–MS, or graphite furnace atomic absorption spectroscopy. 

 The SGLP method was used preferentially for the project samples, and where TCLP was 

applied, SGLP was also applied. TCLP was included because some regulatory groups continue 

to use TCLP results to determine whether a “waste” is hazardous. The SGLP short-term leaching 

procedure was applied to all samples, but for samples with a pH >10, the LTL option was also 

used. CUBs exhibiting a high pH have the potential to undergo hydration reactions that can 

change the leaching profile with time. The EERC documented the impact of ettringite formation 

on leachate concentrations of several elements that are frequently present in CUBs such as 

selenium and boron (9–12). The elements that are most likely to be incorporated into the 

ettringite structure and exhibit a change in leaching profile with time are those that are present as 

oxyanions at high pH. Examples of leaching profiles of high pH CUBs for some trace 

constituents commonly found in CUBs are shown in Figures 2 and 3. 

Figure 2. Long-term leaching results for boron.
8 

Figure 3. Indirect evidence of ettringite formation using SGLP and LTL (note: boron is on a 

secondary axis). 

Vapor-Phase Transport 

Long-Term Ambient Temperature Release 

In order to develop a method to evaluate the potential for release of mercury from CUBs at 

ambient temperatures, several preliminary decisions were made based on the practicality of 

performing this type of evaluation in the laboratory, as follows: 

• In order to measure mercury releases from CUBs, most of which have very low 

concentrations of mercury, samples with relatively high concentrations of mercury 

would be evaluated first. 

• In order to evaluate multiple samples with available equipment and instrumentation, 

released mercury would be collected on analytical gold-coated quartz traps. 

• Because very low release of mercury was anticipated, it was decided to expose a 

column of CUB to low-mercury air rather than expose only the surface of a CUB to the 

ambient temperature low-mercury air. 

 Using these preliminary premises, 250-mL wide-mouth glass test containers were designed 

with bonded Teflon liner caps. Two holes were drilled in the caps to accommodate a silicone 

tube for gas inlet and a Teflon outlet bulkhead fitting. The gas inlet tube extended nearly to the 

bottom of the container while the outlet tube extended only slightly into the container. 
9 

Using these test containers, approximately 150-g aliquots of CUB provided a column of 

material through which the low-mercury air could be transported. Breathing-quality air from a 

cylinder was passed through several sets of gold-coated quartz traps for mercury removal and 

admitted to each of the bottles through a gas distribution manifold that routed the gas through 

0.25-mm-ID gas chromatography (GC) capillary tubing to each of the individual bottles. The 

pressure drop across the GC capillary tubing allowed for the regulation of air flow through each 

bottle by simply adjusting the length of tubing to each bottle. The length of tubing was a nominal 

65 cm. This length of tubing, when pressurized to between 1 and 2 psig through a gas 

distribution manifold, provided a convenient means of regulating gas flow to approximately 

2 cm3

/min. Because of the variability of particle sizes between different ash samples, the sample 

with the initial highest gas flow was left with a 65-cm length of GC tubing, and other samples 

had their tubing lengths shortened until all samples had approximately the same flow rate. The 

air exiting the GC tubing was given a final scrubbing to remove mercury vapor using a goldcoated quartz trap just prior to entering the bottle containing the CUB. After entering the bottles, 

the air passed through the ash and exited to a central mercury collection tube containing two 

separate gold-coated quartz traps. The second outlet or top trap was used to prevent mercury 

contamination from atmospheric mercury. This setup is illustrated in Figure 4. 

The gold-coated quartz trap nearest the exit bulkhead fitting was analyzed multiple times 

with the most typical sampling scheme being one 7-day period followed by two consecutive 90-

day periods. The gold-coated quartz analytical traps were evaluated according to the method 

described in the analytical method section. In order to determine the total mercury released over 

the duration of the experiment, the mercury results from all experimental time segments needs to 

be combined, and the container blank needs to be subtracted. The container blank was 

determined on the empty bottles used to hold the samples. 

Figure 4. Mercury vapor release collection apparatus. 
10 

 Examples of replicate data from a variety of CUB samples are shown in Figure 5. 

Figure 5. Average total long-term ambient-temperature mercury release or sorption as related to 

blank values, pg/g/day. Positive values indicate release and negative values indicate sorption of 

mercury. 

Vapor-Phase Transport 

Thermal Desorption at Elevated Temperature 

 Since mercury and mercury compounds are highly volatile, mercury was expected to be 

released from CUBs when they were exposed to elevated temperatures. Even mercury that is 

sorbed on fly ash, FGD material, or sorbents developed to remove mercury in flue gas is 

expected to have high potential to be released if exposed to high enough temperatures. 

Instrumental and equipment constraints existed for the physical testing of elevated temperature 

release of mercury from CUBs. These constraints included the following: 

• Furnaces available for the experimental apparatus could only achieve maximum 

temperatures of 750°C. 

• Fittings and connecting tubing needed to be heated in order to minimize the loss of 

mercury in the system. 

• Gas flow to remove the mercury from the heated sample cell to the analytical cell 

needed to be constant. 

• Temperature ramping needed to be controlled and consistent between sample runs. 
11 

 The apparatus was constructed as shown in Figure 6. The CUB sample was weighed into a 

quartz tube with quartz wool used to keep the sample in place in the tube. Nominal sample size 

was approximately 1 g. The sample tube was placed into a small tube furnace capable of 

achieving a maximum of 750°C. A programmed temperature controller ramped the furnace from 

ambient to maximum temperature at 25°C per minute. In preliminary experiments, the maximum 

temperature achievable was 700°C, but an improved furnace was incorporated into the apparatus 

to increase the maximum to 750°C. A nitrogen gas flow of 5 cm3/min was introduced into the 

tube furnace. As the mercury and mercury compounds desorbed from the CUB in the sample 

tube, the nitrogen flow carried them though the system to the electrically heated quartz analytical 

cell. The quartz analytical cell was operated at 800°C, allowing the detection of mercury 

compounds by thermally decomposing compounds to form elemental mercury, which can be 

detected by atomic absorption (AA). The analytical cell at the top of the diagram was placed in 

the center-focused beam path of an AA spectrophotometer (AAS). A mercury hollow cathode 

lamp was used as the light source, and the AAS detector was set to the 253.7 nm line for 

mercury. A Hewlett Packard 3395 integrator was used for data collection. 

 Examples of thermal desorption curves generated with this method are shown in Figures 7 

and 8. 

Figure 6. Mercury thermal desorption apparatus. 
12 

Figure 7. Typical thermal desorption curve for fly ash. 

Figure 8. Example of thermal desorption curve for an FGD material. 
13 

Microbiologically Mediated Leaching and Vapor-Phase Transport 

The EERC review of published data on the release of mercury from CUBs (1) reported that 

the only published method demonstrated for use in evaluating the release of mercury from CUBs 

on exposure to natural biota was developed by the EERC. The EERC method has been under 

development since approximately 1999 and has undergone numerous modifications to achieve 

the goal of evaluating the mercury release potential by leaching and offgassing when CUBs are 

under microbiologically mediated conditions. The first experiments performed using early 

versions of the apparatus focused on mercury releases by offgassing. 

The first apparatus assembled to conduct microbiologically mediated vapor-phase mercury 

release used a 250-mL Erlenmeyer flask fitted with an impinger inlet/outlet tube with the inlet 

center shortened to 6 cm below the standard taper. Cylinder gas was passed through several sets 

of gold-coated quartz traps for mercury removal and admitted to each of the flasks through a gas 

distribution manifold that routed the gas through 0.25-mm GC capillary tubing to each of the 

individual flasks. A GC capillary length of approximately 60 cm, when pressurized to between 

1 and 2 psig through a gas distribution manifold, provided a convenient means of regulating gas 

flow to approximately 2 cm3

/min. The gas passed mercury vapor from the head space of the 

flasks to a mercury vapor collection system at the outlet of the flasks, consisting of two traps. 

The nearest trap contained Supelco CarbotrapTM, which collected organomercury compounds, 

followed by a gold-coated quartz trap, which collected elemental mercury. 

The flasks were placed on a 16-flask wrist-action shaker. The experimental matrix 

consisted of eight flasks under anaerobic conditions (using argon) and eight flasks under aerobic 

conditions (using breathing-quality air). In each set of eight flasks, two contained only buffer, 

three contained the CUB with buffer (starved), and three contained the CUB with buffer and 

glucose (fed). An 80-g aliquot of CUB was placed in the flasks, and 100 mL of a phosphate 

buffer (with or without glucose as appropriate) was added to create a neutral pH. The CUBcontaining flasks also had 100 μL of mixed bacterial culture added. The source of bacteria was a 

mixed bacterial inoculum from a brackish wetland. This setup is illustrated in Figure 9. 

This apparatus underwent several iterations as difficulties were identified and solved. The 

wrist-action shaker was abandoned because it was unable to provide adequate suspended sample. 

Instead of the wrist-action shaker, a 9-place stir plate was introduced. This was operated for 

about 20 minutes every 3 hours to maintain sample agitation over the 30-day period of the 

experiment. Additionally, the sample size was reduced to 20 g, and the buffer was increased to 

150 mL to provide adequate sample volume for additional trace element analyses. The buffer 

composition was also altered. It was found that phosphate and nitrate interfered with a 

derivitization step in the determination of organomercury compounds in the solid-phase 

microextraction (SPME) determination using GC separation followed by detection of the 

mercury compounds by atomic fluorescence. This technique is described later. The original 

buffer utilized nominal concentrations of phosphate and nitrate salts. The improved buffer used 

only 100 ppm of phosphate and substituted potassium glutamate as the nitrogen source. This 

simple change appeared to remove the interferences. Additionally, later experiments did not 

involve the use of starved control samples. In current experiments, all samples are fed with 

glucose. This setup is illustrated in Figure 10. 
14 

Figure 9. Microbiologically mediated mercury vapor-phase collection apparatus utilizing a wrist 

action shaker to facilitate mixing. 

Figure 10. Microbiologically mediated mercury vapor-phase collection apparatus utilizing a stir 

plate to facilitate mixing. 
15 

Analyses of mercury and air toxic element releases were performed after a 30-day period. 

The gold-coated quartz traps and CarbotrapsTM were analyzed as described in the analytical 

methods selection. Total mercury concentrations of the leachate were determined using CVAFS. 

Total air toxic element concentrations were determined using ICP–AES or ICP–MS. 

Bacterial counts were performed upon completion of the experiment. A 1-mL aliquot of 

solution was taken from each flask. The aqueous supernate was serially diluted in 0.1% sodium 

pyrophosphate buffer (pH 7) and then used to inoculate a series of tubes containing 1% PTYG 

(peptone, tryptone, yeast extract, glucose) broth. The tubes were incubated at 30°C and growth, 

as turbidity, was monitored over a 3-week period. 

SPME was used in the determination of organomercury species in the liquid portions of the 

samples. SPME is a sample collection technique in our case utilizing a fiber coated with 

polydimethylsiloxane. Samples containing organomercury compounds are first derivatized to 

increase the volatility of organomercury halides such as methylmercuric chloride. The 

derivitization reagents used were sodium tetraethyl borate, sodium tetrapropyl borate, and 

sodium tetraphenyl borate. Sodium tetraethyl borate was most commonly used. In the 

derivitization procedure, derivatizing agent, acetate buffer, an internal standard (usually propyl 

mercuric chloride), and sample were mixed in a septum-capped vial. In a relatively fast reaction, 

the halide is replaced with the appropriate alkyl or aryl group, depending on which derivatizing 

agent is chosen. A SPME fiber was inserted through the septum cap, and the sample was stirred 

using a Teflon-coated stir bar for 20 minutes. After this equilibration time, the SPME fiber was 

introduced into the heated inlet zone of a GC. Sample separation can be accomplished using a 

0.53-mm capillary column 15 or 30 meters in length. The exit end of the column was connected 

to a heated (800°C) quartz tube, and makeup helium gas was added to increase the total flow to 

25–30 mL per minute. The gas was then routed to an AF detector for determination of the 

separated mercury compounds. An example of a SPME chromatogram generated with this 

method is shown in Figure 11. 

Figure 11. Example of a SPME chromatogram. 
16 

SUMMARY 

 Analytical methods were selected based on project needs and the sample types requiring 

analysis. Standard analytical methods were selected and used as frequently as possible. Replicate 

analyses were performed on a regular basis as part of the laboratory quality assurance/quality 

control program. 

 The leaching method selected, the SGLP–LTL, was selected based on EERC experience 

and familiarity with a large number of leaching procedures used to characterize CUBs and the 

appropriate application of those tests. The SGLP–LTL meets the criteria that EERC researchers 

have identified for leaching procedures to provide scientifically valid information. These criteria 

are as follows: 

• Reactivity or other properties of the material being leached that may influence the 

leaching profile. 

• The setting where the material is to be placed and the water that will most likely contact 

that material in that setting. 

• The leaching time required to allow adequate time for hydration reactions to occur in 

reactive materials, such as high calcium coal fly ash. 

 The elevated-temperature vapor-phase release method underwent minor modifications 

early in the project but has been shown to provide reproducible data. The remaining technical 

challenge with the method as employed for this project is the limitations associated with the 

maximum achievable temperature to be applied to the CUB under investigation; and this cannot 

be addressed under this project. 

 The ambient-temperature vapor-phase release method developed for this work also presents 

technical challenges, but they are related to the quantitation limitations for mercury. The 

extremely low levels of mercury released at ambient temperatures are frequently near the levels 

of detection for the analytical system being used. The physical nature of the CUB samples also 

results in variable data and the need to modify the method. As an example, using the apparatus to 

evaluate the potential for release of mercury from a wet FGD material required modification of 

the apparatus to shorten the gas inlet tube to above the level of the sample because gas could not 

be forced through the material when the inlet was near the bottom of the sample container. 

 The method developed to evaluate the microbiologically mediated release of mercury 

underwent a relatively high degree of modification method over the first 2 years of the project. 

The final apparatus description and method now meets the project goals to produce reliable and 

relatively reproducible vapor and leachate samples. An evaluation of the particle-size reduction 

associated with the use of magnetic stir bars in the reaction vessels will be performed, and results 

of that evaluation will be included in future project reports. 
17 

REFERENCES 

1. Hassett, D.J.; Pflughoeft-Hassett, D.F.; Heebink, L.V. A Review of the Current State of the 

Science Related to Rerelease of Mercury from Coal Combustion Products; Final report for 

Utility Solid Waste Activities Group; EERC Publication 2004-EERC-11-01; Energy & 

Environmental Research Center: Grand Forks, ND, Nov 2004. 

2. Energy Information Administration. Annual Energy Outlook 2004 with Projections to 2025; 

U.S. Department of Energy: Washington, DC, 2004. 

3. Regulatory Finding on the Emissions of Hazardous Air Pollutants from Electric Utility 

Steam Generating Units. Fed. Regist. 2000, 65 (245), 79825–79831. 

4. U.S. Environmental Protection Agency. Fact Sheet “EPA Proposes Options for Significantly 

Reducing Mercury Emissions from Electric Utilities,” Dec 15, 2003. 

5. American Society for Testing and Materials. Standard Test Method for Major and Minor 

Elements in Coal and Coke Ash By X-Ray Fluorescence. D4326-04. 

6. American Society for Testing and Materials. Standard Test Methods for Sampling and 

Testing Fly Ash or Natural Pozzolans for Use in Portland-Cement Concrete. C311-04. 

7. U.S. Environmental Protection Agency; Test Methods for Evaluating Solid Waste: 

Physical/Chemical Methods (SW-846), Method 1311, Toxicity Characteristic Leaching 

Procedure. 1992. 

8. American Society for Testing and Materials. Standard Test Method for Shake Extraction of 

Solid Waste with Water. In Annual Book of ASTM Standards; Section 11: Water and 

Environmental Technology, ASTM D3987-85, 2004. 

9. Hassett, D.J.; McCarthy, G.J.; Henke, K.R.; Korynta, E.D. Characterization of a Lignite Ash 

from the METC Gasifier III: Correlations with Leaching Behavior and Mineralogy. In Fly 

Ash and Coal Conversion By-Products: Characterization, Utilization, and Disposal I.; 

McCarthy G.J.; Lauf, R.J., Eds.; Materials Research Society: Pittsburgh, PA, 1985. 

10. Hassett, D.J.; Pflughoeft-Hassett, D.F.; McCarthy, G.J. Ettringite Formation in Coal Ash as 

a Mechanism for Stabilization of Hazardous Trace Elements. In Stabilization and Aquatic 

Uses, Proceedings of the 9th International Ash Use Symposium; Orlando, FL, Jan 22–25, 

1991; EPRI Report GS-7162, Project 3176, 1991; Vol. 2, pp 31-1–31-17. 

11. Hassett, D.J., Thompson, J.S. Ettringite Formation as a Fixation Technology for 

Immobilizing Trace Elements; Final Report to GRI GRI-96/0322. Feb 1997, 41 

12. McCarthy, G.J.; Hassett, D.J.; Bender, J.A. Synthesis, Crystal Chemistry and Stability of 

Ettringite, a Material with Potential Applications in Hazardous Waste Immobilization. In 

Proceedings of the Materials Research Society Symposium; 1992; Vol. 245.
APPENDIX A 

DRAFT ASTM STANDARD METHOD FOR 

SYNTHETIC GROUNDWATER LEACHING 

PROCEDURE
DRAFT

1 

DRAFT ASTM STANDARD METHOD FOR 

SYNTHETIC GROUNDWATER LEACHING PROCEDURE 

1. Scope 

1.1 This method determines the leachability of constituents in wastes, products, or materials 

using a leaching solution designed to simulate leachate anticipated in field conditions. 

The method allows for prediction of changes in leachability brought about as a result of 

the formation of secondary hydrated phases and new minerals through interaction of the 

waste and water over extended periods of time. 

1.2 his method consists of the agitation of waste and a synthetic groundwater solution over 

an extended period of time (greater than 60 days) with sampling at regular intervals. 

1.3 This method allows a comparison of maximum leachate concentration with actual 

concentrations of leachate at time intervals of from 18 hours to 2 months or greater. The 

method allows for determination of mass of analyte mobilized based on a leachate 

concentration and percent of total element leached and provides information to estimate 

leachate concentration trends with respect to time. 

1.4 This method may involve hazardous materials, operations, and equipment. This standard 

does not purport to address all of the safety problems associated with its use. It is the 

responsibility of whoever uses this method to consult and establish appropriate safety 

and health practices and determine the applicability of regulatory limitations prior to use. 

2. Applicable Documents 

2.1 American Society for Testing and Materials (ASTM) Standards: 

D1129 Definitions of Terms Relating to Water 

D1193 Specification for Reagent Water 

D3987 Shake Extraction of Solid Waste with Water 

D2216 Method for Laboratory Determination of Moisture Content of Soils 

2.2Toxicity Characteristic Leaching Procedure (TCLP) EPA Method 1311 

 

3. Definitions 

3.1 For definitions of terms in this test method, see Definitions D1129. 

3.2 Ettringite: Ettringite is a mineral having the nominal composition Ca6Al2(SO4)3(OH)12 

·26H2O. Ettringite is also the family name for a series of related compounds as is the 

case for many mineral families. Ettringite has characteristic structural features that are 

fairly unique. The structure comprises of calcium aluminate columns 

{Ca6Al2(OH)1224H2O}6+ with the channels between these columns containing the other 

components, which include an oxyanion such as sulfate with hydroxide and water 

{(SO4)2-4 (OH)0-4 (H2O)0-6}6-. Ettringite is unique in that several elements that exist as 

oxyanions can substitute for the sulfate in the structure. These elements include but are 

not limited to arsenic, boron, chromium, molybdenum, selenium, and vanadium. 

Ettringite is known to form in the hydration of low-rank coal conversion solid residues 
DRAFT

2 

(CCSRs) and in CCSRs from advanced coal combustion processes such as fluidized-bed 

combustion (FBC) and limestone injection modified burner (LIMB). 

3.3 Synthetic Groundwater: Synthetic groundwater as used in this application refers to a 

solution prepared in the laboratory containing the major geochemical parameters that 

would be found in water likely to contact the disposed CCSR. In the case of rainwater 

contact, this solution would be Type IV water, while with groundwater, a typical 

solution might contain calcium, magnesium, sodium, sulfate, and bicarbonate. 

Groundwater collected at the site of disposal could also be used, although if that were 

the case, corrections would have to be made for concentrations of trace elements already 

present in the water. It has been found with most CCSRs that it is the CCSR that 

regulates the equilibrium concentrations of major constituents in a synthetic groundwater 

leaching procedure; thus the inclusion of major geochemical constituents of actual 

groundwater may be unnecessary in many cases. 

4. Significance and Use 

4.1 This test is intended as a means for determining the mass of analyte readily mobilized by 

leaching with groundwater and also provides a means of determining the trend of 

leachate concentration change, if applicable. This test is intended for use with CCSRs 

and other materials formed under conditions of high temperature. The long-term nature 

of the test allows the determination of changes in concentrations of leached constituents 

as materials react with water to form secondary hydrated phases and other materials not 

present in the original material. 

4.2 This test method is not intended to provide an accurate means of determining actual 

leachate concentrations under field conditions. The test does provide information about 

leaching under field conditions, however, and is useful in predicting the mobility of 

leachable constituents of CCSRs. The information provided from this test is an 

estimation of the mass of analyte that can be solubilized and trend of concentration 

change with respect to time. It should be noted that not all analytes will increase in 

concentration to an equilibrium level. Numerous elements, especially those trace 

elements that exist as oxyanions in aqueous solution, can exhibit a decrease in solution 

concentration after an initial and normally rapid increase in concentration. Additionally, 

major constituents can change solution concentration in a manner that would not be 

predicted on the basis of solubility calculations based on common mineral types, 

especially in CCSRs that form ettringite. 

4.3 Since CCSRs are produced under conditions of high temperature, reactions with water 

during leaching can be expected. If these reactions produce ettringite, the concentrations 

of analytes present in solution as oxyanions can be expected to decrease with respect to 

time as ettringite forms. Other mineral formation can be expected to control leachate 

concentrations of additional analytes in ways not expected from simple solubility 

calculations based on the composition of ash before leaching. Additionally, the 

formation of secondary hydrated phases can be expected to affect the concentrations of 

major components. 
DRAFT

3 

5. Apparatus 

5.1 For a complete description of the apparatus, see ASTM Standard Test Method for Shake 

Extraction of Solid Waste with Water. Any apparatus that can provide conditions of endover-end agitation at 30 plus or minus 2 rpm as specified in the protocol for the TCLP 

can be used in this procedure. 

6. Reagents 

6.1 Purity of Reagents – Reagent-grade chemicals can be used, provided they do not contain 

appreciable amounts of elements to be determined in the extraction test. Reagents must 

be of sufficient purity so they do not interfere with the accuracy of the test or introduce 

bias in the results of analyses of leachates. 

6.2 Purity of Water – Unless otherwise indicated, references to water shall be understood to 

mean Type IV reagent water at 18° to 27°C (Specification D1193). The method by 

which the Type IV water is prepared (distillation, ion exchange, reverse osmosis, etc.) 

should remain constant throughout the test. 

6.3 Synthetic Groundwater – Synthetic groundwater is a leaching solution containing the 

major geochemical parameters important to groundwater likely to contact disposed 

CCSRs. As previously stated, in the case of CCSRs disposed above the water table and 

where the likely water to contact the disposed materials is rainwater, Type IV water can 

be used as the leaching solution. Where the water likely to contact disposed material is 

highly mineralized, either a sample of the water itself or a synthetic mixture prepared in 

the lab will be used. A typical North Dakota synthetic groundwater can be prepared by 

dissolving 0.50 grams of sodium sulfate and 1.00 grams of sodium bicarbonate in one 

liter of Type IV water. The analysis of this solution is as follows: 

Na 436 mg/L 

SO4 338 mg/L 

HCO3 726 mg/L 

pH 8.3–8.7 

This sodium sulfate bicarbonate buffered water is typical for central and western North Dakota. 

Used for leaching low-rank coal ash, calcium was omitted since the ash itself ultimately 

determined the final calcium concentration. 
DRAFT

4 

Other formulas for synthetic groundwater can be prepared as needed for site-specific 

conditions. Care is required when preparing formulations containing calcium and magnesium 

that carbonates not be allowed to precipitate. This can be overcome by adding the reagents in 

the proper order, being certain that all carbonate is buffered to bicarbonate before adding the 

calcium and magnesium. Since sulfuric acid is used for sulfate and acid buffering, having 

excess sulfuric acid acidity will ensure this. A lotus spreadsheet is available for the calculations 

necessary to select reagents for synthetic groundwater formulations, but with the limited 

components, the calculations can also be easily carried out manually. 

7. Sampling 

8. Sample Preparation 

8.1 For sample preparation, see D3987 Standard Test Method for Shake Extraction of Solid 

Waste with Water. 

9. Procedure 

 The laboratory protocol is similar to the U.S. Environmental Protection Agency (EPA) TCLP 

and ASTM D3987 Standard Test Method for Shake Extraction of Solid Waste with Water. The 

primary difference is in the selection and preparation of the extraction fluid and the extension of test 

equilibration time over the prescribed 18-hour period. The long-term leaching aspect of this test is 

especially important since CCSRs can form secondary hydrated phases upon contact with water that 

can have a profound impact on leachate concentration of trace elements, especially elements that tend 

to exist as oxyanions in solution. The formation of secondary hydrated phases is known to take time, 

depending on the source of reactants in the leaching system. Time for complete formation of 

secondary hydrated phases can be from days to months. The test is not intended to carry the leaching 

to complete equilibrium but rather to extend the leaching time long enough for prediction of leachate 

concentration trends. For specifics related to the test, see D3987 Standard Test Method for Shake 

Extraction of Solid Waste with Water, or EPA Method 1311 TCLP, Federal Register, Vol 55, No. 

126, June 29, 1990. 

9.1 Record the physical description of the sample to be tested including particle size as 

known. 

9.2 Solids Content – Determine the solids content of the sample as described in D3987 

Standard Test Method for Shake Extraction of Solid Waste with Water, Sections 9.2.1 

through 9.2.4. 

9.3 Shake Procedure – Prepare the apparatus and begin the test as described in D3987 

Standard Test Method for Shake Extraction of Solid Waste with Water, Sections 9.4 

through 9.7, except that multiple shake test containers are prepared for each sample, the 

number depending on the duration of long-term leaching. Leaching solution shall be 

prepared as described in the following section. Long-term leaching intervals for this 

procedure are 18 hours, 1 week, 1 month, and 2 months. Longer times can be used if 

desired, although trends are usually identified within the 60-day duration of this longterm leaching procedure. An alternative to the use of 2 liters of leaching solution 

involves the use of 225-mL polysulfone bottles. To each bottle, 10 grams (dry weight) of 

ash is added along with 200 mL of leaching solution. Multiple bottles prepared in this 
DRAFT

5 

manner provide at least 150 mL of leachate and allow for the simultaneous extraction of 

a large number of samples with minimal space and equipment. It has been found that the 

standard equipment used for TCLP leaching will generally hold four of the polysulfone 

containers in the same position usually reserved for one 2-liter container. 

9.4 Preparation of Leaching Solution: Leaching solution shall be prepared as recommended 

by an evaluation of field conditions. Where material disposed in a monofill is above the 

water table, the leaching solution shall be Type IV water (D1193 Specification for 

Reagent Water). Where the disposed material will likely be contacted by groundwater, 

either a sample of groundwater from the site or a synthetic groundwater shall be used for 

leaching. The synthetic groundwater if prepared in the lab shall contain all of the 

primary mineralization parameters as determined from an analysis of groundwater from 

the site or from an evaluation of data from analysis reports of water representative of the 

area of disposal. 

9.5 Long-Term Leaching Sampling B Long-term samples are taken from containers prepared 

for the shake test in an identical manner to the specimen for the 18-hour sampling 

period. These containers are sampled at the end of 1 week, 1 month, and 2 months. 

Longer sampling intervals can be added as required. A convenient method for doing this 

procedure is to prepare the samples at time intervals so that all of the samples are 

finished at the same time. For example, one sample is prepared, a second is prepared 1 

month later, a third sample 1 month later, and a final sample 18 hours before the other 

samples are due to be terminated. This saves considerable lab time and expedites the 

entire procedure. 

9.6 Sampling of Leachate B Leachate is sampled for analysis as specified in D3987 Standard 

Test Method for Shake Extraction of Solid Waste with Water, Section 9.8. 

9.7 Analysis 

9.7.1 Selection of Analytes to Be Included in the Report. Analytes include all elements 

present in the ash in high enough concentrations to be problematic in disposal. 

These can be determined through screening procedures such as proton-induced 

x-ray emission (PIXE), instrumental neutron activation analysis (INAA), or 

plasma emission such as inductively coupled argon plasma (ICAP) spectroscopy 

or ICAP–mass spectrometry. Analytes for ash screening generally include the 

eight Resource Conservation and Recovery Act (RCRA) elements for regulatory 

purposes. 

9.7.2 Determination of Total Concentration of Select Analytes. Analytes selected on 

the basis of screening (9.6.1) are determined on a bulk sample prepared by 

digestion of sample in a microwave heated-sealed Teflon bomb. Analyses can be 

performed according to methods for trace analyses in SW846. 

9.7.3 Determination of Analyte Concentrations in Leachates. Concentrations of 

analytes in leachates shall be determined using methods as described in SW846 

or by approved analytical techniques using EPA or other approved techniques. 
DRAFT

6 

All data shall be validated using good laboratory practice and approved quality 

assurance/quality control (QA/QC) procedures. 

10. Calculation 

10.1 Calculate the solids content as specified in D3987 Standard Test Method for Shake 

Extraction of Solid Waste with Water, Section 10.1. 

10.2 Calculation of maximum analyte concentration is determined by dividing the total mass 

of analyte in a sample by the volume of liquid used for leaching. C = M/V where 

C = Concentration of analyte 

M = Mass of sample leached 

V = Volume of leaching solution used 

For this procedure the M:V ratio should be 1:20 as specified in the leaching protocol. 

11. Report 

11.1 The report shall include the following: 

11.1.1 Source of CCSR, date of sampling, and preservation method used for leachates. 

11.1.2 Description of CCSR including coal source, combustion technique, and method 

of sample collection (electrostatic precipitator, baghouse, etc.) 

11.1.3 Solids content (see Method D2216) 

11.1.4 A table of maximum analyte concentrations as determined by the method 

described in Section 10.2. (bulk chemical analysis) 

11.1.5 A table of analyte concentrations as determined from analysis of 18-hour, 1-

week, 1-month, 2-month, and any additional extended time intervals selected. 

12. Precision and Bias 

12.1 No information is presently available on the precision and accuracy or bias of this 

standard practice. It is recommended that standard QA/QC procedures such as analysis 

of duplicate samples and spiking of analyte be used for verification. 

12.2 The precision of this test will vary depending on the material being leached.