oEPA
United States
Environmental Protection .	.	,	f t I	I	I •	•	I
Implementation of the Leaching Environmental
Assessment Framework (LEAF) in the United States
5th International Conference on Industrial and Hazardous
Waste Management
*With EPA's Office of Land
S.Thorneloe, G. Helms* and D. Fagnant* US EPA and Emergency Management
Office of Research and Development
National Risk Management Research Laboratory
Air Pollution Prevention and Control Division
September 29, 2016

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A EPA
I Protection
Outline
United States
Environmental Protection
Agency
•	Introduction
•	Leaching Environmental Assessment
Framework(LEAF) tests
•	Guidance for LEAF implementation
•	Data management tools
•	Next steps
•	LEAF Bibliography
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SB PA
EPA^ Beneficial Use Definition
•	Virtually all industrial sectors generate by-products that are typically discarded but may be used
to replace natural resources and conserve energy
•	EPA has defined beneficial use as the incorporation of an industrial material into a commercial
product that:
1)	provides functional benefit
2)	meets relevant design specifications and performance standards for the proposed use
3)	replaces virgin, raw materials in a product already on the market and
4)	is implemented in a environmentally acceptable manner

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vvEPA
United States
Environmental Protection
Leaching Environmental Assessment Framework
•	LEAF is a collection of ...
•	Four leaching methods
•	Data management tools
•	Geochemical speciation and mass transfer modeling
•	Quality assurance/quality control
•	Integrated leaching assessment approaches
•	... designed to identify characteristic leaching behaviors for a wide range of materials
and associated use and disposal scenarios.
•	Integration of leaching results provides a material-specific "source term" release
estimate for assessing potential groundwater impacts of land placement of materials and
use in material management decisions.
•	More information at http://www.vanderbilt.edu/leaching

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a-epa
United States
Environmental Protection
Agency
LEAF Leaching Tests
Equilibrium-based leaching tests
•	Batch tests carried out on size reduced material
•	Aim to measure contaminant release related
to specific chemical conditions (pH, LS ratio)
•	Method 13 13 - pH dependence & titration curve
•	Method 13 16 — LS dependence
Mass transport rate-based leaching tests
•	Carried out either on monolithic or compacted granular materials
•	Aim to determine contaminant release rates by accounting for both
chemical and physical properties of the material
•	Method 1315- monolith & compacted granular options
Percolation (column) leaching tests
•	May be either equilibrium or mass transfer rate
•	Method 1314- upflow column, local equilibrium (LS ratio)
*Posted to SW-846 Validated Methods iri August 2013

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Simulation vs. Characterization
Simulation-based Leaching Approaches
•	Designed to provide representative leachate under specified conditions
•	Simple implementation (e.g., single-batch methods likeTCLP or SPLP*) and
interpretation (e.g., comparison of results to target values[acceptance criteria])
•	Limitations
•	Representativeness of testing to actual disposal or use conditions
•	Results cannot be reliably extended to scenarios that differ from simulated conditions
Characterization-based Leaching Approach
•	Evaluate intrinsic leaching parameters under broad range of conditions
•	Focus on parameters that vary in the environment and significantly affect leaching***
•	More complex; sometimes requiring multiple leaching tests
•	Results can be applied to "what if" analysis of different disposal or use scenarios
•	Allows a common basis for comparison across materials and field conditions
Parameters of most concern include pH, US, waste form and redox
*TCLP-Toxicity Characteristic Leaching Procedure
**SPLP-Synthetic Precipitation Leaching Procedure
*** Parameters of most concern include pH, L/S and waste form; other parameters such as
redox conditions can be important for some wastes

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*How and When do I use LEAF?
•	LEAF test methods allow for;
•	Varying pH
•	Varying US ratio
•	Measuring monolith or granular samples
•	Up flow percolation
•	What tests does my management scenario call for?
•	How do I interpret my results?
•	Soon to be released guidance: LEAF How-To Guide
*The LEAF methods were developed and have been validated for evaluating
the leaching potential of inorganics wastes and constituents.

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vvEPA
United States
Environmental Protection
Agency
LEAF How-To Guide
Purpose
•	Improve understanding of
leaching and how leaching
occurs and is evaluated
•	Describe the LEAF
framework and the suite of
LEAF methods
•	Explain how to apply LEAF
and how leaching results are
used
•	Describe data management
and analysis tools
8
Purpose and Audiences
Audiences
•	Decision makers for waste
management, beneficial use of
secondary materials, and site
remediation
•	Risk assessors
•	State environmental agency
officials
•	Waste generators
•	Analytical laboratories
•	Technical consultants and other
interested stakeholders

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vvEPA
United States
Environmental Protection
Agency
LEAF How-To Guide: Topics Covered
•	General leaching overview
•	How to proceed through the LEAF approach
•	How to apply LEAF and special considerations to assess for selected
management scenarios
•	Case study examples to illustrate how to use LEAF to develop source terms
using LEAF data include evaluating materials for reuse and disposal and
evaluating treatment effectiveness.
•	How to use leaching test results to model releases and inform reuse
decisions

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oEPA
United States
Environmental Protection
Agency
LEAF How-To Guide: Stepwise Approach to LEAF Testing
Integrated stepwise
approach for evaluating
leaching behavior of
materials
•	Considers pH, \JS, and
material properties across
a range of plausible field
conditions
Flexible framework
•	Tailor testing to site
conditions and select the
extent of testing based on
the level of information
needed
•	More precise and accurate
estimation of leaching is
achievable as conservative
assumptions are
progressively replaced
with more accurate values
Unacceptable for scenario
Content
More Conservative
Less Accurate
Available Content
Test
• LEAF 1313
Equilibrium
• LEAF 1313,
	J
Mass Transfer Rate
Test
• LEAF 1315
Acceptable for scenario
Increased Testing
Less Conservative
More Accurate
I Reference Threshold

Constituent of Potential Concern (COPC).
COPCs shown are for illustrative purposes only

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oEPA
United States
Environmental Protection
Agency
LEAF Assessment Approach
•Using leaching tests to characterize a
material (A*).
•Evaluating the leaching of constituents
from the material in the context of the
proposed use, treatment, or disposal
application in conjunction with mass
transport models to produce a leaching
source term model (A).
•Estimating constituent release from the
application scenario considering water
contact rates, flow rates, or frequencies
(B).
•Applying national or regional dilution
and attenuation factors (DAFs), or site-
specific groundwater fate and transport
modeling, to estimate constituent
concentrations at the point of
compliance for comparison with
applicable thresholds (C).
Material Leaching Tests
Broad-based characterization of
intrinsic leaching behavior
A* j-
Roadbase
1	Material-specific: leaching tests
2	Scenario-specific: test results or by modeling (integrated with
local water contact information)
3	Location-specific: for example, recharge rate or depth to
groundwater
Adapted from Kossori, van der Shot et al. (2014)
Material Characterization1
Leaching in Context of the
Application2
Use as Source Term
Constituent Release from
Application Scenario
DAF or Model Scenario3
Constituent Concentration
at Point of Compliance vs.
Threshold (e.g., DWS)

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vvEPA
United States
Environmental Protection
Agency
LEAF Data Management Tools
•	LeachXS Lite software and data templates facilitate data management,
evaluation, and reporting
•	Data templates provided as excel spreadsheets for each method
•	Perform basic, required calculations (e.g., moisture content)
•	Record laboratory data
•	Archive analytical data with laboratory information
•	Form the upload file to materials database
•	Software for LEAF data management, visualization and processing
•	Compare leaching test data
•	Between materials for a single constituent (e.g., As in two different CCRs)
•	Between constituents in a single material (e.g., Ba and S04 in cement)
•	To default or user-defined values indicating QA limits or health-based threshold values)
	 • Export leaching data to Excel spreadsheets
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oEPA
United States
Environmental Protection
Agency
LeachXS Lite Inputs
LEAF Scenario
Evaluation Guide
Materials
(Leaching Data, Total Content,
Physical Properties)
Materials
Database
Scenarios
(e.g., Fill Characteristics, Geometry,
Infiltration, Hydrologic Properties)
Scenario
Database
Reference Thresholds
(e.g., Reference thresholds for drinking
water, ecological values, etc.)
Reference
~ Threshold
Database
Databases and Outputs
LeachXS
Lite
LEAF
Screening
Assessment
Excel
Spreadsheets
(Data, Figures)
Reports
Leaching
Source Terms
(Inputs to
groundwater fate
and transport models,
e.g., IWEM, etc.)

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Next Steps
Public review of LEAF implementation guidance - Fall 2016
Developing additional applications for integration into
LeachXS-Lite
Conducting updates and maintenance to software and other
data management tools as needed
Developing leach testing for organic wastes and constituents
based on LEAF principles of accounting for the effects of most
important factors affecting leaching.

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vvEPA
United States
Environmental Protection
Agency
Bibliography of available LEAF documents (cont.)
•	Kosson, D. S., van der Sloot, H. A., Sanchez, F„ and Garrabrants, A. C. (2002). An integrated framework for evaluating laagbin waste management and
utilization of secondary materials. Environmental Engineering Science (Vol. 19).
•	Kosson, D. S., van der Sloot, H. A., anflighmy.T.T. (1996).An approach for estimation of contaminant release during utilization and disposal of municipal waste
combustion residues Journa/ of Hazardous Materials (Vol.47, pp. 43-75).
•	Sanchez, F.,Mattus, C. H„ Morris, M. I., and Kosson, D. S. (2002). Use of a New Leaching Test Framework for Evaluation Alternative Treatment Processes for
Mercury-Contaminated Soils .Environmental Engineering Science (Vol. 19, pp. 251-269).
•	Thorneloe, S. (2012). Leaching Environmental Assessment Framework to evaluate beneficial use and disposal decisions. Presentd at 37th Annual EPA-A&MWA
Information Exchange, US EPA. November 28.
•	Thorneloe, S. A., Kosson, D. S., Sanchez, F„ Garrabrants, A. C., and Helms, G. (2010). Evaluating the fate of metals inpsbiHution control residues from coal-fired
power plants. Environmental Science & Technology (Vol. 44, pp. 7351 -7356).
•	US EPA. (2006). Characterization of MercuryEnriched Coal Combustion Residues from Electric Utilities Using Enhanced Sorbents for Mercury Control.
EPA/600/R-06/008.
•	US EPA. (2008). Characterization of Coal Combustion Residues from Electric Utilities Using Wet Scrubbers for MultPollutant Control. EPA-600/R-08/077.
•	US EPA. (2009). Characterization of Coal Combustion Residues from Electric Utilities- Leaching and Characterization Data. EPA-600/R-09/151.
•	US EPA. (2010). Background Information for the Leaching Environmental Assessment Framework (LEAF) Test Methods. EPA/600/IR0/170.
•	US EPA. (2012b). The Impact of Coal Combustion Fly Ash Used as a Supplemental Cementitious Material on the Leaching Constituats from Cements and
Concretes. EPA 600/R-12/704.
•	US EPA. (2012c). Interlaboratory Validation of the Leaching Environmental Assessment Framework (LEAF) Method 1313 and Method 3 16. EPA 600/R-12/623.
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vvEPA
United States
Environmental ProtectiorLM^^ ^11^	I	f	® I	II	I	i *	i	y	w
Bibliography of available LEAF documents (cont.)
•	US EPA. (2012d). Interlaboratory Validation of the Leaching Environmental Assessment Framework (LEAF) Method 1314 and Method 1315.
EPA 600/R-12/624.
•	US EPA. (20l2e). Leaching Behavior of "AGREMAX" Collected from a CoaFired Power Plant in Puerto Rico. EPA/600/R-12/724.
•	US EPA. (2014a). Coal Combustion Residual Beneficial Use Evaluation: Fly Ash Concrete and FGD Gypsum Wallboard. Office of Sod Waste and
Emergency Response, Office of Resource Conservation and Recovery Washington, D.C.
•	US EPA. (2014b). Human and Ecological Risk Assessment of Coal Combustion Residuals. Regulation Identifier Number: 205CAE8I. December.
•	US EPA. (2014c). Leaching Test Relationships, Laborator»jto-Field Comparisons and Recommendations for Leaching Evaluation using the Leaching
Environmental Assessment Framework (LEAF). EPA-600/R-14/061.
•	US EPA. (20l4d). Method 1313 LiquidSolid Partitioning as Function of Extract pH using a Parallel Batch Extraction Procedure SW-846 UpdateV.
•	US EPA. (20l4e). Method 1314 LiquidSolid Partitioning as a Function of Liquid-Solid Ratio for Constituents in Solid Materials Using an Up-Flow
Percolation Column Procedure SW-846 Update V.
•	US EPA. (20l4f). Method 1315 Mass Transfer Rates in Monolithic and Compacted Granular MaterialsSW-846 UpdateV.
•	US EPA. (20l4g). Method 1316 LiquidSolid Partitioning as a Function of Liquid-Solid Ratio using a Parallel Batch Extraction Procedure SW-846
Update V.
•	US EPA (2016) Workshop Report: Considerations for Developing Leaching Tests for Semiand Non-Volatile Organic Compounds, EPA/600/R-
16/057, April 1016.
•	van der Sloot, H. A., and Kosson, D. S. (2012). Use characterization leaching tests and associated modelling tools in assessing the hazardous nature
of wastes. Journal of Hazardous Materials (Vol. 207-208, pp. 36-43).
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