1 Starting Soon: Integrated DNAPL Site CharacterizationIntegrated DNAPL Site Characterization and Tools Selection (ISC-1, 2015) Download PowerPoint file Download files for reference during the training class Flowcharts: Excel file: Using Adobe Connect Related Links (on right) Select name of link Click “Browse To” Full Screen button near top of page Follow ITRC No associated notes.

2 Integrated DNAPL Site Characterization and Tools SelectionWelcome – Thanks for joining this ITRC Training Class Integrated DNAPL Site Characterization and Tools Selection Sites contaminated with dense nonaqueous phase liquids (DNAPLs) and DNAPL mixtures present significant environmental challenges. Despite the decades spent on characterizing and attempting to remediate DNAPL sites, substantial risk remains. Inadequate characterization of site geology as well as the distribution, characteristics, and behavior of contaminants -- by relying on traditional monitoring well methods rather than more innovative and integrated approaches -- has limited the success of many remediation efforts. The Integrated DNAPL Site Characterization Team has synthesized the knowledge about DNAPL site characterization and remediation acquired over the past several decades, and has integrated that information into a new document, Integrated DNAPL Site Characterization and Tools Selection (ISC-1, 2015). This guidance is a resource to inform regulators, responsible parties, other problem holders, consultants, community stakeholders, and other interested parties of the critical concepts related to characterization approaches and tools for collecting subsurface data at DNAPL sites. After this associated training, participants will be able to use the ITRC Integrated DNAPL Site Characterization and Tools Selection (ISC-1, 2015) guidance to develop and support an integrated approach to DNAPL site characterization, including: - Identify what site conditions must be considered when developing an informative DNAPL conceptual site model (CSM) - Define an objectives-based DNAPL characterization strategy - Understand what tools and resources are available to improve the identification, collection, and evaluation of appropriate site characterization data - Navigate the DNAPL characterization tools table and select appropriate technologies to fill site-specific data gaps For reference during the training class, participants should have a copy of Figure 4-1, the integrated site characterization flow diagram from the ITRC Technical and Regulatory Guidance document: Integrated DNAPL Site Characterization and Tools Selection (ISC-1, 2015) and available as a PDF at ITRC (Interstate Technology and Regulatory Council) Training Co-Sponsored by: US EPA Technology Innovation and Field Services Division (TIFSD) (www.clu-in.org) ITRC Training Program: Phone: Integrated DNAPL Site Characterization and Tools Selection (ISC-1, 2015) Sponsored by: Interstate Technology and Regulatory Council (www.itrcweb.org) Hosted by: US EPA Clean Up Information Network (www.cluin.org)

3 Housekeeping Course time is 2¼ hours This event is being recordedTrainers control slides Want to control your own slides? You can download presentation file on Clu-in training page Questions and feedback Throughout training: type in the “Q & A” box At Q&A breaks: unmute your phone with #6 to ask out loud At end of class: Feedback form available from last slide Need confirmation of your participation today? Fill out the feedback form and check box for confirmation and certificate Although I’m sure that some of you are familiar with these rules from previous CLU-IN events, let’s run through them quickly for our new participants. We have started the seminar with all phone lines muted to prevent background noise. Please keep your phone lines muted during the seminar to minimize disruption and background noise. During the question and answer break, press #6 to unmute your lines to ask a question (note: *6 to mute again). Also, please do NOT put this call on hold as this may bring unwanted background music over the lines and interrupt the seminar. Use the “Q&A” box to ask questions, make comments, or report technical problems any time. For questions and comments provided out loud, please hold until the designated Q&A breaks. Everyone – please complete the feedback form before you leave the training website. Link to feedback form is available on last slide. Copyright 2016 Interstate Technology & Regulatory Council, 50 F Street, NW, Suite 350, Washington, DC 20001 3

4 ITRC (www.itrcweb.org) – Shaping the Future of Regulatory AcceptanceDisclaimer Full version in “Notes” section Partially funded by the U.S. government ITRC nor US government warranty material ITRC nor US government endorse specific products ITRC materials copyrighted – see usage policy Available from Technical and regulatory guidance documents Internet-based and classroom training schedule More… Host organization Network State regulators All 50 states, PR, DC Federal partners ITRC Industry Affiliates Program Academia Community stakeholders Follow ITRC DOE DOD EPA The Interstate Technology and Regulatory Council (ITRC) is a state-led coalition of regulators, industry experts, citizen stakeholders, academia and federal partners that work to achieve regulatory acceptance of environmental technologies and innovative approaches. ITRC consists of all 50 states (and Puerto Rico and the District of Columbia) that work to break down barriers and reduce compliance costs, making it easier to use new technologies and helping states maximize resources. ITRC brings together a diverse mix of environmental experts and stakeholders from both the public and private sectors to broaden and deepen technical knowledge and advance the regulatory acceptance of environmental technologies. Together, we’re building the environmental community’s ability to expedite quality decision making while protecting human health and the environment. With our network of organizations and individuals throughout the environmental community, ITRC is a unique catalyst for dialogue between regulators and the regulated community. For a state to be a member of ITRC their environmental agency must designate a State Point of Contact. To find out who your State POC is check out the “contacts” section at Also, click on “membership” to learn how you can become a member of an ITRC Technical Team. Disclaimer: This material 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 and no official endorsement should be inferred.  The information provided in documents, training curricula, and other print or electronic materials created by the Interstate Technology and Regulatory Council (“ITRC” and such materials are referred to as “ITRC Materials”) is intended as a general reference to help regulators and others develop a consistent approach to their evaluation, regulatory approval, and deployment of environmental technologies. The information in ITRC Materials was formulated to be reliable and accurate. However, the information is provided "as is" and use of this information is at the users’ own risk.  ITRC Materials do not necessarily address all applicable health and safety risks and precautions with respect to particular materials, conditions, or procedures in specific applications of any technology. Consequently, ITRC recommends consulting applicable standards, laws, regulations, suppliers of materials, and material safety data sheets for information concerning safety and health risks and precautions and compliance with then-applicable laws and regulations. ITRC, ERIS and ECOS shall not be liable in the event of any conflict between information in ITRC Materials and such laws, regulations, and/or other ordinances. The content in ITRC Materials may be revised or withdrawn at any time without prior notice.  ITRC, ERIS, and ECOS make no representations or warranties, express or implied, with respect to information in ITRC Materials and specifically disclaim all warranties to the fullest extent permitted by law (including, but not limited to, merchantability or fitness for a particular purpose). ITRC, ERIS, and ECOS will not accept liability for damages of any kind that result from acting upon or using this information.  ITRC, ERIS, and ECOS do not endorse or recommend the use of specific technology or technology provider through ITRC Materials. Reference to technologies, products, or services offered by other parties does not constitute a guarantee by ITRC, ERIS, and ECOS of the quality or value of those technologies, products, or services. Information in ITRC Materials is for general reference only; it should not be construed as definitive guidance for any specific site and is not a substitute for consultation with qualified professional advisors.

5 Meet the ITRC Trainers Nathan Hagelin Tamzen Macbeth CDM SmithHelena, MT Nathan Hagelin AMEC Foster Wheeler Environment & Infrastructure Portland, ME Alec Naugle California Water Boards Oakland, CA waterboards.ca.gov Ryan Wymore CDM Smith Denver, CO Tamzen Macbeth is an Associate Engineer at CDM Smith out of Helena, Montana. She has worked for CDM since Previously, she worked for 7 years at North Wind Inc. Tamzen is an environmental engineer with an interdisciplinary academic and research background in microbiology and engineering. She specializes in the development, demonstration and application of innovative, cost-effective technologies for contaminated groundwater. Specifically, she is experienced in all aspects of remedies from characterization to remediation for DNAPLs, dissolved organic, inorganic, and radioactive contaminants under CERCLA and RCRA regulatory processes. She has expertise in a variety of chemical, biological, thermal, extraction and solidification/stabilization remediation techniques as well as natural attenuation. Her current work focuses developing combined technology approaches, and innovative characterization techniques such as mass flux and mass discharge metrics. Since 2004, Tamzen has contributed to the ITRC as a team member and instructor for the ITRC’s Bioremediation of DNAPLs, Integrated DNAPL Site Strategy, Molecular Diagnostics and DNAPL Characterization teams. Tamzen earned a bachelor's degree in Microbiology in 2000 and a master’s degree in Environmental Engineering in 2002 both from Idaho State University in Pocatello, Idaho, and a doctoral degree from in Civil and Environmental Engineering in 2008 from the University of Idaho in Moscow, Idaho. Alec Naugle is a Senior Engineering Geologist in the Groundwater Protection Division at the California Regional Water Quality Control Board, San Francisco Bay Region where he has worked since Alec leads a unit that oversees solvent and petroleum hydrocarbon cleanups at Department of Energy laboratories and closed military bases, many of which are undergoing conversion for civilian use. He is also co-chair of the Region's technical groundwater committee, which supports the Board's planning activities related to groundwater quality and beneficial use. Prior to joining the Board, Alec worked as a consultant on various military and private sites in California and the Northeast and as a regulator in the UST program. Alec has been a member of ITRC since 2000 participating in the Permeable Reactive Barriers, Enhanced Attenuation: Chlorinated Organics, and Integrated DNAPL Site Strategy teams. Alec earned a bachelor’s degree in chemistry and geology from Marietta College in Marietta, Ohio in 1986 and a master’s degree in groundwater hydrology from the University of California at Davis in Alec is a Registered Professional Geologist in California. Nathan Hagelin is the Practice Area Leader for Environmental Remediation for Amec Foster Wheeler Environment and Infrastructure, Inc. in Portland, Maine and has been with the company since Nathan leads Amec Foster Wheeler's environmental remediation resources, drives technical quality in the delivery of remediation services, develops client technical symposiums and internal training programs, attracts and retains key remediation resources, and leads AMEC's participation in key conferences and trade groups. He is a Senior Principal Geologist with environmental consulting experience in both the public and private sectors, and prior experience as a U.S. Geological Survey Hydrologist (1986 to 1989). His experience includes hydrogeologic investigations, remedial action planning, remedial technology selection and implementation, solid- and hazardous-waste landfill closures, PCB Remediation, RCRA corrective action, industrial facility closure, litigation support, brownfields redevelopment, consent agreement/order negotiations. He serves as project manager, technical leader and senior technical reviewer on projects ranging from site assessments to remedial investigations, RCRA facility investigations, remedial designs and remedial actions, and long term operation, maintenance, and monitoring programs. His areas of expertise include: RCRA, CRCLA, TSCA/Megarule, PCB and VOC remediation, hydrogeology - contamination assessments, DNAPL Investigations, remedial investigations, landfill closure, landfill post-closure monitoring and maintenance programs, RCRA Facility Investigations, RCRA facility closures, voluntary corrective actions, technical writing, environmental site assessments, regulatory negotiations, and technical support for litigation. He has contributed to ITRC since 2012 as a member and trainer for the DNAPL Site Characterization team and since 2015 as a member of the Characterization and Remediation in Fractured Rock team. Nathan earned a bachelor's degree in Geology from the University of Connecticut in Storrs, Connecticut in 1983 and a master's degree in Geology from the City College of New York in New York City in He is a Certified Geologist in the State of Maine and a Licensed Site Professional in the State of Connecticut. Ryan A. Wymore, P.E., rejoined CDM Smith in Denver, CO in He serves as a national resource for evaluation, selection, and implementation of remediation strategies and solutions. Ryan has specialized in innovative groundwater remediation technologies, particularly bioremediation, monitored natural attenuation and chemical oxidation. Previously, he work at Geosyntec Consultants in , CDM Smith from , at North Wind Inc. from , and at the Idaho National Laboratory from He has given over eighty presentations at various local, regional, national, and international symposia and meetings. Since 2002, he has worked with various ITRC teams that addressed DNAPLs, bioremediation, enhanced attenuation, and Environmental Molecular Diagnostics. He was an instructor on the ITRC Internet-based training courses: DNAPL Performance Assessment, Bioremediation of DNAPLs, and Integrated DNAPL Site Strategy. Ryan earned a bachelor's degree in Biological Systems Engineering from the University of Nebraska-Lincoln in 1997 and a master's degree in Civil/Environmental Engineering from the University of Idaho in Moscow, Idaho in He is a registered Professional Engineer in the state of Idaho and Colorado in the environmental discipline.

6 The Problem: Dense Non-Aqueous Phase Liquid (DNAPL) SitesNot achieving cleanup goals Spending time and money, but substantial risk remains Common site challenges Incomplete understanding of DNAPL sites Complex matrix – manmade and natural Unrealistic remedial objectives Selected remedy is not satisfactory Restoring sites contaminated by chlorinated solvents to typical regulatory criteria (low parts-per-billion concentrations) within a generation (~20 years) has proven exceptionally difficult, although there have been successes. Site managers must recognize that complete restoration of many of these sites will require prolonged treatment and involve several remediation technologies. To make as much progress as possible requires a thorough understanding of the site, clear descriptions of achievable objectives, and use of more than one remedial technology. Making efficient progress will require an adaptive management approach, and may also require transitioning from one remedy to another as the optimum range of a technique is surpassed. Targeted monitoring should be used and re-evaluation should be done periodically. Coal Tar

7 Poll Question For sites that you work on, what year did cleanup activities begin? Please provide a short answer Poll Question No associated notes.

8 The Problem: Outdated DNAPL Site Characterization ConceptsConsidered contaminant flow was similar to groundwater flow Simplifying assumptions in equations based on Darcy flow led to inadequate characterization of Site geologic heterogeneity Contaminant Distribution Characteristics Behavior This approach limited success of site remediation activities 1980’s view When we began to address subsurface contamination in the 1970’s, many practitioners came from the water supply industry We used a series of during site characterization and remedial design. These simplifications in many cases led to inadequate characterization of the site geologic heterogeneity and distribution, characteristics, and behavior of contaminants This approach has helped to limit the success of many site remediation activities Receptor Receptor Plume

9 The Solution: An Integrated DNAPL Site StrategyITRC Technical and Regulatory Guidance Document: Integrated DNAPL Site Strategy (IDSS-1, 2011) Comprehensive site management Use at any point in site lifecycle Key topics Conceptual site model (CSM) Remedial objectives Remedial approach Monitoring approach Evaluating your remedy Associated Internet-based training ITRC’s Integrated Dense Nonaqueous Phase Liquid Site Strategy (IDSS-1, 2011) technical and regulatory guidance document will assist site managers in development of an integrated site remedial strategy. This course highlights five important features of an IDSS including: A conceptual site model (CSM) that is based on reliable characterization and an understanding of the subsurface conditions that control contaminant transport, reactivity, and distribution Remedial objectives and performance metrics that are clear, concise, and measureable Treatment technologies applied to optimize performance and take advantage of potential synergistic effects Monitoring based on interim and final cleanup objectives, the selected treatment technology and approach, and remedial performance goals Reevaluating the strategy repeatedly and even modifying the approach when objectives are not being met or when alternative methods offer similar or better outcomes at lower cost ITRC IDSS-1, Figure 1-2

10 Adding to the Solution: Integrated DNAPL Site CharacterizationHandout provided ITRC Technical and Regulatory Guidance Document: Integrated DNAPL Site Characterization (ISC-1, 2015) Benefits More accurate conceptual site models (CSMs) Improved predictability of plume behavior and risks More defensible knowledge of contaminant distribution Facilitates communication Reduced uncertainty Better performing remedies Benefits of using ITRC Technical and Regulatory Guidance Document: Integrated DNAPL Site Characterization (ISC-1, 2015) Better performing remedies and improved predictability of plume behavior and risks. Increased spatial precision and accuracy of characterization data, leading to more accurate CSMs. More defensible knowledge of contaminant distribution. Improved selection of remedial measures to address subsurface zones that feed plumes and drive up potential exposure. Use of real-time field screening tools for site characterization that may minimize the number of permanent monitoring wells, thus providing more optimal use of available personnel and financial resources. Facilitates communication of site conditions and improves enhanced stakeholder understanding and involvement. Reduced uncertainty in risk evaluation, remedy selection, and site management decisions, leading to better reductions in risk and protection of natural resources. ITRC ISC-1, Figure 4-1

11 Incorporated into the Solution: New DNAPL Site Characterization ApproachesHeterogeneity replaces homogeneity Anisotropy replaces isotropy Diffusion replaces dispersion Back-diffusion is a significant source of contamination and plume growth Non-Gaussian distribution Transient replaces steady-state conditions Nonlinear replaces linear sorption Non-ideal sorption replaces ideal sorption No associated notes.

12 After this training you should be able to:Apply the ITRC document to develop and support an Integrated DNAPL Site Characterization approach Understand what characteristics of site conditions must be considered when developing an informative DNAPL conceptual site model (CSM) Defining an integrated DNAPL characterization strategy Understand what tools and resources are available to improve the identification, collection, and evaluation of appropriate site characterization data Navigate the DNAPL characterization tools table and select appropriate technologies to fill site-specific data gaps No associated notes.

13 If you gain nothing else: Geology Controls DNAPL Mobility!Soil heterogeneity leads to differences in subsurface pore structure and capillary properties Significant variations can occur over very small distances/ intervals NAPL migration is strongly influenced by the topography of geologic layers No associated notes. Photo Courtesy of Fred Payne, Arcadis, Inc ISC-1, Chapter 2

14 Training Overview DNAPL Characteristics Life Cycle of a DNAPL SiteIntegrated Site Characterization Plan Tools Selection Implementation Summary Understanding the subsurface behavior of DNAPLs is technically-challenging and methods for site characterization have evolved. The objective of this document is to describe the tools and resources that can improve the identification, collection, and evaluation of appropriate site characterization data to prepare more accurate CSMs. This guidance describes how, with the current understanding of subsurface contaminant behavior, both existing and new tools and techniques can be used to measure physical, chemical, and hydrologic subsurface parameters to better characterize the subsurface. The expected results of using this guidance are more accurate site-specific CSMs, which can then be applied in the ITRC Integrated DNAPL Site Strategy (ITRC 2011). ISC-1, Chapter 2

15 DNAPLs – Not Just Chlorinated Solvents!PCE in Soil Core Mixed Aged Motor Oil/Bunker, Aryl Phosphate and PCB in Soil Core Heterogeneity replaces homogeneity. Anisotropy replaces isotropy. Coal Tar

16 DNAPL Types Common types of DNAPLs Chlorinated solvents Coal tarCreosote Heavy petroleum such as some #6/Bunker fuel oil products Oils containing Polychlorinated biphenyls (PCBs) Chapter 2 of this document reviews DNAPL types and the characteristics that control their distribution, fate, and transport in the subsurface. Although these issues are addressed in peer-reviewed literature, they are also summarized in this document because they are crucial to designing an adequate characterization program.

17 See Table 2.1 Physical properties of example NAPLs & reference fluidsPoll Question What DNAPLs do you have at your sites? (select all the apply) Chlorinated solvents Coal tar Creosote Heavy petroleum hydrocarbons PCBs Pesticides Mercury Other None Poll Question Physical properties of Example NAPLs & reference fluids See Table 2.1 Physical properties of example NAPLs & reference fluids

18 Important DNAPL Properties Affecting MobilityDNAPL Chemical & Physical Properties Volatility No associated notes. Composition Modified from ISC-1, Chapter 2

19 DNAPL Density Describes the mass per unit volume of the DNAPL and is sometimes expressed as specific gravity (SG), which is the density relative to water By definition, all DNAPLs have a SG greater than 1.0 Some DNAPLs have a SG >1.5 (e.g., PCE) While others have a SG barely greater than water Higher density DNAPLs have a greater driving force for downward movement, while in other cases other DNAPLs may be almost neutrally buoyant. KEY POINT: Gravitational forces overwhelm hydraulic gradients

20 DNAPL Aqueous Solubility (Cw,sol)Amount of a compound that dissolves in water at equilibrium Often different in site groundwater than in the laboratory DNAPL Component Density (g/mL) Solubility (mg/L) Types of Sites Trichloroethylene (TCE) 1.46 1,100 Solvent Pentachlorophenol (PCP) 1.98 20 Wood Treatment Acid Tar (H2SO4 & Hydrocarbons) 1.84 Miscible Refineries Mention effects of pure vs mixed DNAPLs: effect on dissolution etc KEY POINT: Influences loss of mass to plume and trapped soil water

21 DNAPL Viscosity (Dynamic)Represents the resistance to shear (flow) of the fluid Temperature dependent µw = cP 25 oC µw = cP 20 oC Coal Tar 1 Coal Tar 2 Coal Tar 3 400 200 Viscosity, µ (cP) No associated notes. Temperature, T (oC) KEY POINT: Influences mobility in the subsurface

22 DNAPL Volatility Volatility - Henry’s Constant (KH)Vapor Pressure (VPsat or P0) See also ITRC’s Vapor Intrusion Pathway: A Practical Guideline (VI-1, 2007) Vapor (gas phase) Water (+ dissolved contaminant) - Vapor Pressure (VPsat or P0) Maximum amount of a pure compound that can exist in the gas phase - Henry’s Law (KH) Amount of dissolved organic contaminant that will exist in the gas phase KEY POINT: Influences mass loss in the unsaturated zone and risk of vapor intrusion (VI)

23 DNAPL Composition Properties of mixed DNAPL are different from pure component properties Chlorinated solvents often include other compounds such as grease, oils or stabilizers For mixed sources, chlorinated compounds from DNAPL could partition into LNAPL NAPL weathering occurs in subsurface Coal Tar – Water Interfacial Films Loss of the soluble fraction of the NAPL The properties we have just discussed can “be found” in published literature. HOWEVER It is important to stress that the properties of pure laboratory grade chemicals can be very different from what may be present at a site. KEY POINT: Analysis of both the chemical and physical properties of your NAPL is recommended, if a NAPL sample can be collected

24 DNAPL Interactions with the Sub-Surface Media Affecting MobilityThe following properties significantly affect the interactions between DNAPLs and sub-surface media: DNAPL Migration is to a large extent controlled by the following DNAPL Properties and the DNAPL interactions with the Sub-Surface Media Modified from ISC-1, Chapter 2

25 Interfacial Tension and WettabilityInteract to control the capillary forces that govern NAPL migration Non Wetting Wetting Graphic from Stone Environmental Wettability Represents whether a fluid is wicked into or repelled out of the subsurface media, defined by the contact angle  of the DNAPL fluid against the matrix materials in the presence of water. Wettability is a combined property of the NAPL and the subsurface formation materials, chemistry, presence of co-contaminants Interfacial Tension Represents the force parallel to the interface of one fluid with another fluid (usually air or water), which leads to the formation of a meniscus and the development of capillary forces and a pressure difference between different fluids Wettability of soils may change after exposure to NAPL KEY POINT: Influences capillary pressure and vertical migration

26 Capillary Pressure (Pc)Represents the pressure difference between two fluids sharing pore space Pc = Pn + Pw (Bear, 1972) Where Pn is the NAPL pressure and Pw is the water pressure Pc is a non-linear function of S, with Pc increasing at greater saturation of the non-wetting fluid (Lenhard and Parker, 1987) No associated notes. KEY POINT: Variance of pore spaces within geologic media can dictate vertical DNAPL migration

27 Capillary Pressure of Coarser Layers and DNAPL Entry5 3 1 DNAPL Pool Capillary Barrier DNAPL Pool Height (m) No associated notes. Silt Fine Sand Medium Sand Coarse Sand Creosote Coal tar Chlorinated Solvent Mixed DNAPL Kueper et. Al. 2003, An illustrated Handbook of DNAPL Transport and Fate in the Subsurface

28 DNAPL Saturation Saturation, Relative Permeability, and Capillary Pressure Saturation (S) S is the proportion (percentage) of the pore space occupied by a fluid (NAPL, air, or water) Ranges from 0 to 1.0 (0 to 100%) Residual Saturation (Sr) Sr is the saturation of NAPL remaining when NAPL is no longer mobile No associated notes. KEY POINT: Strongly affected by geologic heterogeneity

29 NAPL Saturation and MobilityWhen S < Sr NAPL will be immobile unless NAPL or solid phase properties change When S > Sr NAPL may be mobile or potentially mobile NAPL may be potentially mobile but not moving (Pennell et al., 1996, ES&T) No associated notes. Figure modified from ISC-1, Chapter 2 KEY POINT: A continuous NAPL phase must be connected to transmit pressure head that overcomes the entry pressure and allows DNAPL to migrate

30 Groundwater Movement Through a DNAPL ZoneRelative permeability (kr) kr for groundwater = 1.0 at DNAPL S = 0 kr for DNAPL approaches 1 at as DNAPL S approaches 1 (Parker and Lenhard 1987) The value of kr, ranges from 0 to 1.0 as a non-linear function of saturation (S) No associated notes. figure modified from ISC-1, Chapter 2 KEY POINT: The presence of NAPL reduces the effective hydraulic conductivity of the media

31 Training Overview DNAPL Characteristics Life Cycle of a DNAPL SiteIntegrated Site Characterization Plan Tools Selection Implementation Summary Understanding the subsurface behavior of DNAPLs is technically-challenging and methods for site characterization have evolved. The objective of this document is to describe the tools and resources that can improve the identification, collection, and evaluation of appropriate site characterization data to prepare more accurate CSMs. This guidance describes how, with the current understanding of subsurface contaminant behavior, both existing and new tools and techniques can be used to measure physical, chemical, and hydrologic subsurface parameters to better characterize the subsurface. The expected results of using this guidance are more accurate site-specific CSMs, which can then be applied in the ITRC Integrated DNAPL Site Strategy (ITRC 2011). ISC-1, Chapter 3

32 DNAPL Life Cycle – Classical ModelSource Zone Evolution Active source Migrating DNAPL DNAPL vaporization DNAPL dissolution No associated notes. Kueper et al., 2013

33 Secondary Sources within Groundwater PlumesWe are now revising our definition of “DNAPL Source Zone” The hunt for DNAPL is often distracting DNAPL is no longer considered the only source of groundwater contamination Sorption/desorption from aquifer matrix Matrix diffusion into/out of low K zones No associated notes. KEY POINT: These mechanisms may control the longevity of dissolved phase plumes at DNAPL or former DNAPL sites

34 Redefining the DNAPL Source Term: Apparent Secondary SourcesAreas impacted by DNAPL DNAPL Source Areas Unsaturated (Vadose) Zone Secondary Sources DNAPL may have dissolved or the DNAPL may be remediated Molecular diffusion into low k zones Matrix Diffusion from sources within plume Sorption/ desorption to aquifer matrix These actions may control the longevity long term migration of the dissolved phase plumes at DNAL sites Slow Desorption from aquifer solids Modified from ISC-1, Chapter 2

35 “Sorption” - Adsorption & AbsorptionA portion of the contaminant mass will adsorb/sorb to the aquifer matrix at equilibrium based on contaminant concentration and the contaminant’s affinity to the matrix Contaminant mass will desorb from matrix into groundwater as “cleaner” groundwater migrates through system CWater Water CSolid Solid (Soil) Chapter 2 of this document reviews DNAPL types and the characteristics that control their distribution, fate, and transport in the subsurface. Although these issues are addressed in peer-reviewed literature, they are also summarized in this document because they are crucial to designing an adequate characterization program. KEY POINT: Desorption contributes to retardation and longevity of dissolved phase contaminant plumes

36 Matrix Diffusion: “Back Diffusion”Early time Molecular Diffusion into low permeability zones in the aquifer matrix: “Matrix Diffusion” Late time “Back Diffusion” out of low permeability zones into higher permeability zones No associated notes. ITRC IDSS-1, Figure 2-5 & 2-6 KEY POINT: Back Diffusion contributes to retardation and longevity of dissolved phase contaminant plumes

37 Controlling Role of Geology in Matrix DiffusionNo associated notes. Figure courtesy of Fred Payne, Arcadis

38 14-Compartment Model: Phase Distribution and Mass TransferSource Zone Plume Phase/Zone Low Perm. Transmissive Vapor DNAPL NA Aqueous Sorbed Vapor Intrusion Capillary Barrier Matrix Diffusion Matrix Diffusion No associated notes. Sorption ITRC IDSS-1, Table 2-2 from Sale and Newell 2011 KEY POINT: The 14-Compartment Model helps Stakeholders align on the Life Cycle of the Site and Characterization Objectives

39 DNAPL Life Cycle – Early StageNo associated notes. ZONE SOURCE PLUME Lower-K Transmissive Vapor LOW MODERATE DNAPL HIGH Aqueous Sorbed Kueper et al., 2013

40 Prolonged Early Stage BehaviorLow solubility and high viscosity DNAPLs High DNAPL saturations and still immobile. Highly DNAPL saturation causes flow by-passing No associated notes. KEY POINT: Coal tar and creosote sites may remain as Early Stage for generations

41 DNAPL Life Cycle – Middle StageNo associated notes. ZONE SOURCE PLUME Lower-K Transmissive Vapor MODERATE DNAPL Aqueous Sorbed Kueper et al., 2013

42 Diffusion Replaces Dispersion in Dissolved Phase PlumesAs the length scale of interest decreases Diffusion replaces Dispersion in plume behavior Geologic heterogeneity and anisotropy also lead to numerous small plumes within each groundwater plume Diffusion replaces dispersion. Figures courtesy of Fred Payne, Arcadis

43 Heterogeneity Replaces HomogeneitySimplifying the subsurface as homogeneous & isotropic has not worked well for remediation-scale plume geometry Anisotropy replaces isotropy Non-ideal behavior is as pronounced in the vertical Borden Tracer Simulation – Combined Heterogeneity and Diffusivity Effects 3 Depth (m) Anisotropy replaces isotropy Heterogeneity replaces homogeneity 0 5 10 Distance (m) Figure courtesy of Fred Payne, Arcadis

44 DNAPL Life Cycle – Late StageNo associated notes. ZONE SOURCE PLUME Lower-K Transmissive Vapor LOW DNAPL Aqueous MODERATE Sorbed Kueper et al., 2013

45 Poll Question Based on what we have just presented, and remembering that life-cycle phase is not only dependent on age of the site; what phase is your site? Early Middle Late Select more than one if you have multiple sites in different phases Poll Question No associated notes.

46 Understanding Your DNAPL CSMCharacterizing sites contaminated with DNAPLs needs to take into account Geology Depositional environment, media properties Orientation of fractures, bedding planes Characteristics of the released DNAPL Distribution DNAPL in Subsurface Media Life-cycle of your DNAPL site Roles of Matrix Diffusion and Non-ideal Sorption The objectives of the characterization and decisions that need to be made No associated notes.

47 Q&A Follow ITRC Handout provided ITRC IDSS-1, Figure 1-2No associated notes. ITRC IDSS-1, Figure 1-2 ITRC ISC-1, Figure 4-1

48 Training Overview DNAPL Characteristics Life Cycle of a DNAPL SiteIntegrated Site Characterization Plan Tools Selection Implementation Summary Now that you’ve heard about DNAPL characteristics and the life cycle of a DNAPL site, we want to discuss a process that we’re calling integrated site characterization for DNAPL sites. It’s a process that integrates the planning, collection, and evaluation of characterization data. One major highlight of this process is a module on new and existing data collection tools and techniques for DNAPL sites, including the physical, chemical, and hydrologic parameters that they measure. The integrated site characterization process is presented in Chapters 4 through 6 in pour guidance document. The purpose is to help users prepare more accurate conceptual site models. And that translates to a more effective Integrated DNAPL Site Strategy, which was the subject of our 2011 guidance.

49 Integrated Site CharacterizationFlexible, iterative 8-step process for CSM refinement Focus areas Data resolution matches scale of heterogeneity Objectives are clear and actionable Tools are optimal for site conditions and data needs So, what is integrated site characterization? Well, basically it’s A Flexible, iterative, 8-step process to encourage refinement of the Conceptual Site Model over the project lifecycle with information obtained during any phase. That’s what’s shown in the roadmap on the right side. The process was developed to focus on particular aspects that are common to DNAPL site characterization. This includes matching spatial data resolution with the scale of subsurface heterogeneity that is controlling contaminant distribution and movement. As discussed earlier, discounting the effects of heterogeneity on contaminant distribution and matrix diffusion, is a major issue for DNAPL sites and why remedies fail. It also includes: developing clear, actionable data collection objectives, and selecting appropriate tools for optimal data collection considering site conditions and data needs I should take a moment to emphasize that data collection objectives are not to be confused with remedial action objectives. Data collection objectives are the reasons why you are collecting the data, what kind of data, how much data, and the quality of the data in order to answer specific questions about site characterization. Remedial action objectives are all about the reasons why remediation is needed and the specific goals for implementing it. ******** NEW CONCEPTS FOR CONTAMNANT FATE AND TRANSPORT Heterogeneity replaces homogeneity Anisotropy replaces isotropy Diffusion replaces dispersion Matrix back diffusion must be evaluated as a source Lognormal replaces gaussian Transient replaces steady state conditions Non-linear replaces linear sorption Non-ideal replaces ideal sorption

50 Benefits of Integrated Site CharacterizationReduces uncertainties to improve CSM Enables more efficient remedies ITRC Integrated DNAPL Site Strategy (IDSS-1, 2011) Avoids costly do-overs Supports stakeholder needs and confidence The benefits of integrated site characterization are best understood in light of common problems with DNAPL sites. Often the controlling heterogeneities have not been fully characterized, which has led to inadequate data resolution and undervaluing the need to fully assess contaminant distribution, particularly in storage zones that account for back diffusion. And that has lead to many remedy failures. So the benefits include: Reducing uncertainty and enabling development of more accurate Conceptual Site Models Improving identification, collection, and evaluation of site characterization data to develop appropriate and achievable remedial objectives and more efficient remedies. The ITRC’s Integrated DNAPL Site Strategy document does a good job summarizing why developing appropriate and achievable objectives is so critical…and it is worth noting that the integrated site characterization approach we’re discussing today is really part of an overall Integrated DNAPL Site Strategy. So if you are not familiar with our 2012 document, you can download it from the ITRC’s website. Another major benefit is what we call “avoiding costly do-overs” prompted by ineffective remedies. As I said, too often this is the result of insufficient data resolution, data gaps, or unfocused characterization objectives.

51 Integrated Site CharacterizationPlan characterization (1-4) Define the problem Identify data needs and resolution Develop data collection objectives Design data collection and analysis plan Select tools (5) Implement investigation and update CSM (6-8) In this training we’re going to present the 8-step approach as three modules. The first is a module for planning your site characterization, which is covered by the first four steps of the ISC module that are shown here. I’ll go into more detail about each step later on, but for now I just want to preview what the planning module includes. Defining the uncertainties and deficiencies in the Conceptual Site Model Identifying data needs and resolution appropriate for site conditions Developing clear, actionable data collection objectives Designing a data collection and analysis plan The second module is for selecting your investigation tools, which is based on your data needs and the hydrogeologic environment. Nathan/Jeremy will present that module after I’m done. The third module is about implementing the investigation. This also includes evaluating and interpreting the data and then circling back to update the Conceptual Site Model. Heather/Ryan will present that module after the Tools Selection module.

52 Poll Question Do you have a DNAPL site that is being characterized for the first time or where prior characterization was insufficient? Yes – first time Yes – insufficient No Poll Question So before we go any further, please take a few moments to respond to our poll question. “Do you have a DNAPL site that is being characterized for the first time or where prior characterization was insufficient?” There are three possible responses – Yes, I have a site that is being characterized for the first time; or, Yes, my site is being re-characterized, perhaps because it’s just a second or third iteration that as planned, or perhaps you’re at the remedial design stage and need to have better delineation for targeting the source zone; or perhaps because the initial resolution was insufficient or there were unanswered questions. Or maybe you don’t have a site that’s being characterized. Either way, this guidance provides an optimal planning approach for planning a DNAPL site characterization, and minimizing the chances of collecting insufficient or inadequate data.

53 Data Quality Objectives are “Built in”USEPA Data Quality Objectives Step 1: State Problem Step 2: Identity Goal of Study Step 3: Identify Information Inputs Step 4: Define Boundaries of Study Step 5: Develop Analytical Approach Step 6: Specify Performance or Acceptance Criteria Step 7: Develop Plan for Obtaining Data Most of us are familiar with U.S. Environmental Protection Agency’s seven step Data Quality Objectives Process. And you might be thinking that integrated site characterization sounds a lot like data quality objectives. So this slide simply shows that the Data Quality Objectives process is meant to be fully captured within the planning module of integrated site characterization. It’s just that we wanted to design an approach that would focus attention on specific DNAPL site problems, such as insufficient data resolution and lack of appropriate objectives. ****** Directly from EPA “The DQO Process may be applied to all programs involving the collection of environmental data and apply to programs with objectives that cover decision making, estimation, and modeling in support of research studies, monitoring programs, regulation development, and compliance support activities. When the goal of the study is to support decision making, the DQO Process applies systematic planning and statistical hypothesis testing methodology to decide between alternatives. When the goal of the study is to support estimation, modeling, or research, the DQO Process develops an analytic approach and data collection strategy that is effective and efficient.”

54 Step 1: Define Problem and Assess CSM UncertaintiesAssess existing CSM Define problem Define uncertainties Now I’m going to walk through the first four steps of integrate site characterization. In between each step I’m going to switch to a case example of a small drycleaner site that illustrates how each step was applied. Step 1 is about defining the problem and assessing the uncertainties with the Conceptual Site Model. The challenge is to define the problem in terms of uncertainties to better understand what’s missing and what’s needed. For example, if the problem is that the extent of contamination is not fully defined, the uncertainty might about low data density in a particular direction, or misunderstanding of groundwater flow direction. If the problem is about ineffective remediation, then their may be uncertainty about the true extent of the source area or presence of undefined preferential pathways. Critically review existing information: If your site has already been characterized to some degree, and many DNAPL sites have, then it’s critical to review what is known or suspected and assess the existing data quality and data gaps. Some of the key areas you’ll want to focus on include: Lithologic and structural heterogeneity – that’s what’s controlling groundwater flow and contaminant distribution and movement. For example, it includes soil type, permeability, presence or absence of buried channels and aquitards, fractures, fracture density, and depth to base units. Vertical sampling resolution – for example, was continuous coring done for soil? Were different groundwater intervals sampled? What are the well screen lengths? What are the gaps? Historic sources, including the contaminants, and the nature of the source and source area – for example was it a mixture or pure NAPL release? Is there any data to suggest the remaining presence of DNAPL? Chemical signatures in the groundwater data – for example, what’s the relative abundance of parent and daughter contaminants at different locations. Does that suggest anything about the source, distribution, or attenuation? As you heard earlier, the use of tools such as the 14-compartment model can help assess the relative strengths and weaknesses of existing data for each compartment….which can help identify uncertainties and data needs.

55 Case Example – Dry Cleaner SiteCommercial & residential location Shallow groundwater (<20’ bgs) Five MWs; 10-ft screens 18 soil borings; 5-ft samples No soil-gas evaluation In situ chemical oxidation (ISCO) & enhanced in situ bioremediation (EISB) injections in source area & plume N Groundwater Plume Area Garage Dry Cleaner Gasoline Station Case Example Garage In this case example, a dry cleaner site in was initially investigated with 18 soil borings and 5 monitoring wells from 2004 through Groundwater flow is toward the southeast, and there are commercial and residential buildings nearby. Soil borings were sampled every five feet and monitoring wells were set with ten-foot screens from 15 to 25 feet below ground surface. The small circles represent soil borings and the triangles are monitoring wells. Red indicates that the results exceeded compliance standards, green means the results were below standards. The black dashed line represents the initial interpretation of the gw plume area. The blue dashed line represents the initial interpretation of the source area. In 2008, remediation was performed on both the source and plume areas using in-situ chemical oxidation (in the source area) and enhanced in-situ bioremediation (in the plume area). But in 2010, the monitoring data showed that the plume still remained above standards. So the first problem is that while this may seem like a relatively high number of sample locations, no attempt was made to match the sample resolution with the scale of the controlling heterogeneities. Furthermore, groundwater was sampled using 10-ft well screens, which may not be sufficient to provide sufficient vertical delineation. In our guidance document we caution against the use of monitoring wells for DNAPL site characterization because they tend to average concentrations over large vertical distances, they’re an expensive compared to other characterization methods, and once installed, they usually required to be monitored and can bias the site characterization picture for a long time to come. Monitoring wells are best used to monitor contaminants trends once delineation is complete, not for characterization. The second problem is that no effectiveness evaluation was planned after remediation was conducted in So when monitoring data showed that the groundwater plume remained above standards two years after remediation, there was no consensus about where the problem lay. The third problem is that the vapor intrusion pathway had not been assessed despite the existence of nearby residential buildings. This was probably because vapor intrusion has been an evolving concern in recent years and may not have been given much thought when the investigation began in But now it’s a big concern. In 2011 when the site was revisited, uncertainties remained about the completeness of source and plume delineation, remedy effectiveness, and vapor intrusion threats to nearby residential and commercial building occupants. Garage Garage Vacant Residence Apartments GW 40 ft (approx.) Monitoring Well Garage Residence Soil Boring exceeds criteria below criteria

56 Step 1: Define Problem and Assess UncertaintiesUncertain plume delineation; no down-gradient control Source area inferred, not confirmed No remedy evaluation No soil gas or VI assessment N Groundwater Plume Area Garage Dry Cleaner Gasoline Station Case Example Garage In this case example, a dry cleaner site in was initially investigated with 18 soil borings and 5 monitoring wells from 2004 through Groundwater flow is toward the southeast, and there are commercial and residential buildings nearby. Soil borings were sampled every five feet and monitoring wells were set with ten-foot screens from 15 to 25 feet below ground surface. The small circles represent soil borings and the triangles are monitoring wells. Red indicates that the results exceeded compliance standards, green means the results were below standards. The black dashed line represents the initial interpretation of the gw plume area. The blue dashed line represents the initial interpretation of the source area. In 2008, remediation was performed on both the source and plume areas using in-situ chemical oxidation (in the source area) and enhanced in-situ bioremediation (in the plume area). But in 2010, the monitoring data showed that the plume still remained above standards. So the first problem is that while this may seem like a relatively high number of sample locations, no attempt was made to match the sample resolution with the scale of the controlling heterogeneities. Furthermore, groundwater was sampled using 10-ft well screens, which may not be sufficient to provide sufficient vertical delineation. In our guidance document we caution against the use of monitoring wells for DNAPL site characterization because they tend to average concentrations over large vertical distances, they’re an expensive compared to other characterization methods, and once installed, they usually required to be monitored and can bias the site characterization picture for a long time to come. Monitoring wells are best used to monitor contaminants trends once delineation is complete, not for characterization. The second problem is that no effectiveness evaluation was planned after remediation was conducted in So when monitoring data showed that the groundwater plume remained above standards two years after remediation, there was no consensus about where the problem lay. The third problem is that the vapor intrusion pathway had not been assessed despite the existence of nearby residential buildings. This was probably because vapor intrusion has been an evolving concern in recent years and may not have been given much thought when the investigation began in But now it’s a big concern. In 2011 when the site was revisited, uncertainties remained about the completeness of source and plume delineation, remedy effectiveness, and vapor intrusion threats to nearby residential and commercial building occupants. Garage Garage Vacant Residence Apartments GW 40 ft (approx.) Monitoring Well Garage Residence Soil Boring exceeds criteria below criteria

57 Step 2: Identify Data Needs & Spatial ResolutionTranslate uncertainties into data needs Determine resolution needed to assess controlling heterogeneities Step 2 in the integrated site characterization planning process is about identifying specific data needs and the spatial resolution needed for data collection. The first concern is to translate the uncertainties in the conceptual site model into data needs. This is typically straight forward. For example, if there is uncertainty in the contaminant distribution, it might be because you’re lacking soil or groundwater data in a particular direction or depth. If plume stability is uncertain, you might need more time-series groundwater data. The second concern is to determine sufficient spatial resolution. This is a bit more challenging because you may not know the scale of the controlling heterogeneities at your site. What you want is spatial resolution that enables you to assess the nature of the subsurface heterogeneity that is effectively controlling contaminant distribution and transport. For DNAPL sites it’s particularly important to distinguish among transport and storage zones to determine if there may a matrix diffusion problem. Also, we’re using the concept of sufficient resolution rather than saying you must have high resolution. That’s because once you have captured the appropriate resolution and know where to look, you may find that you don’t need the same resolution everywhere. The big question is how do I know what level of resolution to characterize to? Ans: While there may be many techniques, including use of geophysical methods, you’ll never really know until you’ve tried. So one way is to pick a small, off-source area and do what is typically considered high resolution, to get a spot assessment of the heterogeneity scale. Keep in mind that contaminant distribution in DNAPL source areas can vary widely over small distances and can easily be missed. ******* My site has been characterized using conventional techniques. Do I need to redo this work using the higher resolution methods? If you think your existing site conceptual model is sound and the site management strategy has been successful, an extensive supplemental site characterization program is not needed. If questions remain about key components of the site conceptual model—e.g., hydrogeology; contaminant distribution, fate, and transport properties; and risk—additional characterization using high-resolution techniques can be both beneficial and cost-effective. Some sites may not have been precisely delineated by conventional characterization methods (e.g., soil borings and monitoring wells); in such cases, high-resolution techniques can provide clarity on how to move forward in the site remediation/ management process.

58 Step 2: Identify Data Needs & Spatial ResolutionAdditional groundwater samples needed to define plume extent N Garage Dry Cleaner Gasoline Station Case Example Garage Additional soil samples needed to confirm source area Switching back to the drycleaner case example, there were three primary data gaps identified that naturally flow from the uncertainties. Recall that the uncertainties existed about 1) completeness of source zone and plume delineation, 2) the effectiveness of the in-situ remedies that were attempted, and 3) the degree of vapor intrusion threat to occupants of nearby buildings, including commercial and residential structures. So the data gaps that were identified include: First, contaminant concentrations in soil and groundwater to bound the source area and plume both laterally and vertically. This was particularly true to the south and west because that is the direction of groundwater flow, and the initial investigation was limited by property access issues in that direction – a fence line along the southern property boundary. Second, soil and groundwater data to demonstrate the effect of the in-situ remedy. Recall that ISCO was used in the source area and EISB was used for the plume. And third, lack of soil-gas (and potentially indoor air data) to assess potential vapor intrusion threats. Garage Garage Vacant Residence GW Apartments 40 ft (approx.) Monitoring Well Garage Residence Soil Boring exceeds criteria below criteria Soil-gas samples needed to assessment VI threat

59 Step 2: Identify Data Needs & Spatial ResolutionGarage Dry Cleaner Gasoline Station Garage Garage Garage Vacant Case Example Residence Apartments exceeds criteria below criteria 40 ft (approx.) GW This slide shows the uncertainty in the vertical directions across the plume and source area. Monitoring Well Garage Residence Soil Boring 10 20 Original vertically-delineated plume ?? Depth (ft) Uncertain vertical delineation in source area

60 Step 3: Establish Data Collection ObjectivesSpecific, Clear, Actionable Consider data types, quality, density, and resolution Step 3 in the integrated site characterization planning process is about establishing data collection objectives. The real point here is to emphasize that objectives need to be specific, clear, and actionable, and must consider the data types, data quality, density, and spatial resolution.

61 Step 3: Example Data Collection ObjectivesDelineate extent of dissolved-phase plume; determine stability and attenuation rate Grab groundwater samples at X and Y depths Soil borings every X feet to capture subsurface variability Delineate to drinking water standards Install three to five wells; monitor along axis of flow Quarterly for two years Evaluate C vs T and C vs. distance trends Specify COCs and geochemical parameters The idea with developing data collection objectives is to start with a broad statement or question that you are trying to answer about what is needed. Then, continually refine it until you have something that is as clear and detailed as possible. Our IDSS document includes a section about developing remedial action objectives that are Specific, Measureable, Achievable, Relevant, and Timebound, which is what the SMART acronym means. The same idea applies to data collection objectives to make them as SMART as possible. Here is an example…

62 Poll Question Have you ever collected data types that were not optimal for deciding what to do next? Yes No Poll Question Let’s take a moment to respond to another poll question: “Have you ever collected data types that were not optimal for deciding what to do next?” This might be because your data needs weren’t fully determined, as in Step 2, or because your data collection objectives were not clear or specific enough.

63 Step 3: Drycleaner Site Data Collection ObjectivesDefine plume extent exceeding standards Assess remedy progress – soil and GW samples Assess shallow soil vapor & VI threat Streamline assessment – days not weeks Data types & resolution Continuous cores; samples at lithologic boundaries Groundwater samples every 4’ Soil gas at 5 and 10 feet Case Example Switching back to the drycleaner case example, these are the broad objectives that were established. The key objectives were to define the soil and groundwater volumes exceeding the compliance standards Assess remedy progress to date, and Assess shallow soil vapor concentrations. A key objective was to complete the work in a short time period, not drag out the duration with multiple sampling mobilizations. These objectives were further refined to identify the data types and resolution, including: Continuous coring with a direct push to a depth of about 25 feet Soil samples at lithologic boundaries Grab groundwater samples every 4’ Shallow soil gas samples at two depths

64 Step 4: Data Collection & Analysis PlanWrite work plan Recognize data limitations Select data management tool Develop data analysis process Consider real-time analysis Step 4 is where Steps 1 -3 are documented – in a work plan. Goal is to achieve your characterization objectives and manage site specific uncertainties to the point that decisions about the site can be made. Items to consider while figuring out how to collect data include: Recognize data limitations Select data management tool Develop data analysis process Given the necessary dynamic nature of characterization – consider real-time analyses and how that data will be interpreted! Screening Method Qualitative tools Direct subsequent data collection Fill in the Gaps Contaminant flux Horizontal and vertical resolution vital Map Extent Delineate source Decision making

65 Step 4: Drycleaner Site Data Collection & Analysis PlanSoil vapor sampling Case Example With the objectives in mind, a plan was developed for the dry cleaner site using the TRIAD approach, two Geoprobes and a mobile laboratory to collect high-resolution samples in the source area, grab groundwater samples, and soil vapor samples across the site. Direct sampling ion trap mass spectrometry (SW846 Method 8265) with mobile lab provides up to 80 soil/groundwater and 60 soil vapor VOC analyses per day Triad ES mobile lab and Geoprobe

66 Step 4: Data Collection & Analysis PlanUpdated Groundwater Plume Area 16 borings 80 soil samples (~5 per boring) 48 grab groundwater samples (~3 per boring) N Soil sampling to confirm source area Garage Dry Cleaner Gasoline Station Garage Case Example Garage Garage Vacant The drycleaner site plan included 16 direct push, continuous cored boring locations. Borings were planned for advancement to about 25 feet with soil samples to be collected at lithologic boundaries and grab groundwater samples to be collected every four feet. The planned number of soil samples to be collected for laboratory analysis was about 80, and the planned number of groundwater samples was 48. Residence Apartments 40 ft (approx.) GW Monitoring Well Garage Residence Soil Boring Proposed sample location GW sampling to better define plume extent to southeast exceeds criteria below criteria

67 Step 4: Data Collection & Analysis PlanShallow soil vapor results Soil gas 12 points 24 samples N Garage Dry Cleaner Gasoline Station Garage Case Example Garage Garage Vacant The plan also included shallow soil gas collection at two depths at 12 locations. Samples depths would be about 5 and 10 feet. So the overall data collection plan for the drycleaner site was fairly robust. But that’s what was needed to capture the effects of the subsurface variability on the distribution of the contaminants in the soil. Groundwater, and soil gas. Keep in mind, this was essentially do-over. So this planning phase benefited from a lot of prior knowledge about the site, such as lithology, groundwater flow direction, and some initial understanding of contaminant distribution, albeit somewhat in error. This kind of planning done from the start would almost certainly have saved time and money, particularly when it came to the remediation. Residence GW Apartments 40 ft (approx.) Monitoring Well Garage Residence Soil Boring Soil-gas samples needed to assessment VI threat Proposed soil-gas sample location

68 Summary – Integrated Site CharacterizationIntegrated Site Characterization flow chart Planning Tool Selection Implementation Planning module Step 1: Define problem and uncertainties Step 2: Identify data gaps & resolution Step 3: Develop data collection objectives Step 4: Design data collection & analysis plan Similar to DQO process; focus on DNAPL sites No associated notes.

69 Training Overview DNAPL Characteristics Life Cycle of a DNAPL SiteIntegrated Site Characterization Plan Tools Selection Implementation Summary No associated notes. ISC-1, Chapter 4

70 Tools Selection Process: Contents of this SectionOrientation to the tools matrix Tools selection framework Tools matrix functionality Case studies Summary No associated notes.

71 Poll Question Which of these tools have been used on your sites? Check all that apply. Split Spoon Sampler Hydraulic Profiling Tool Membrane Interface Probe Portable GC/MS Colorimetric Screening Electrical Resistivity Tomography Raman Spectroscopy Fluorescence In-situ Hybridization (FISH) Partitioning Interwell Tracer Test (PITT) Poll Question No associated notes.

72 Tools Matrix Format and LocationThe tools matrix is a downloadable excel spreadsheet located in Section 4.6 Tools segregated into categories and subcategories, selected by subject matter experts A living resource intended to be updated periodically Tool Geophysics Surface Geophysics Downhole Testing Hydraulic Testing Single well tests Cross Borehole Testing Vapor and Soil Gas Sampling Solid Media Sampling and Analysis Methods Solid Media Sampling Methods Solid Media Evaluation and Testing Methods Direct Push Logging (In-Situ) Discrete Groundwater Sampling & Profiling Multilevel sampling DNAPL Presence Chemical Screening Environmental Molecular Diagnostics Microbial Diagnostics Stable Isotope and Environmental Tracers On-site Analytical No associated notes.

73 Orientation to the Tools MatrixContains over 100 tools Sorted by: Characterization objective Geology Hydrogeology Chemistry Effectiveness in media Unconsolidated/Bedrock Unsaturated/Saturated Ranked by data quality Quantitative Semi-quantitative Qualitative No associated notes.

74 Tools Matrix FunctionalityClick any box for a description or definition Click No associated notes.

75 Detailed Tool Descriptions (Appendix D)Click on any tool Additional reference material Description Applicability Limitations No associated notes. Click

76 Shaded Boxes Denote Tool Meets ObjectiveTools collect these types of information No associated notes. Green shading indicates that tool is applicable to characterization objective

77 Using the Tools Matrix Down-selecting appropriate tools to meet your characterization objectives A systematic process Select your categories: geology, hydrogeology, chemistry Select parameters of interest Identify geologic media (e.g., unconsolidated, bedrock) Select saturated or unsaturated zone Choose data quality (quantitative, semi-quantitative, qualitative) Apply filters, evaluate tools for effectiveness, availability, and cost Ultimately, final tools selection is site-specific, dependent upon team experience, availability, and cost No associated notes.

78 1. Select Category All Geology Hydrogeology Chemistry – All – Soil Gas– Groundwater – Solid Media No associated notes.

79 2. Select Parameters of InterestAll Lithology Contacts Porosity Permeability Dual Permeability Faults Fractures Fracture Density Fracture Sets Rock Competence Mineralogy No associated notes.

80 3. Identify Geologic MediaAll Bedrock Unconsolidated No associated notes.

81 4. Identify Zone All Unsaturated Saturated No associated notes.

82 5. Choose Data Quality (Q) quantitative (SQ) semi-quantitative(QL) qualitative No associated notes.

83 6. Apply Filters, Evaluate ToolsClick No associated notes.

84 Perform Additional Searches to Find More Tools for Different ObjectivesAdditional parameters can be added or removed from any given search No associated notes.

85 Add Parameters to a previous searchMultiple searches can be saved on one matrix No associated notes.

86 Apply Selected Tool(s)Incorporate selected tool(s) into characterization plan Implement plan, evaluate data, update CSM, reassess characterization objectives Repeat tool selection process as necessary No associated notes.

87 Case Example – Characterization ObjectivesReturning to Case Example from prior section – Characterization Objective: Delineate lateral and vertical extent of dissolved-phase plume; determine stability and rate of attenuation. Goal: Define boundary exceeding groundwater standards Assess remedy progress – soil and groundwater samples Assess shallow soil vapor impacts Case Example No associated notes.

88 Case Example – Select Tools Matrix FiltersType Chemistry - All Parameter Contaminant Concentration Subsurface Media Unconsolidated Subsurface Zone All Data Quality (Q) Quantitative Case Example No associated notes.

89 Case Example – Apply FiltersNo associated notes.

90 Case Example – Applicable ToolsNo associated notes.

91 Case Example – Tools SelectionSearch returns 22 tools Considering desire to expedite the assessment, project team selected Direct Push borings with continuous soil sampling and GW grab sampling on 4-foot intervals Active Soil Gas Survey at two depth intervals Direct Sampling Ion Trap Mass Spectrometer (DSITMS) mobile field lab Active Soil Gas Survey Case Example No associated notes. DSITMS Mobil Lab

92 Example #2 Characterization Objective – Determine the porosity of a fractured bedrock formation in a DNAPL source zone to evaluate the potential storage capacity of the rock Type Geology Parameter Porosity Subsurface Media Bedrock Subsurface Zone Saturated Data Quality (Q) Qualitative No associated notes.

93 Example #2 – Bedrock PorosityNo associated notes. Over 100 tools distilled to 10 that are applicable to the Characterization Objective

94 Example #3 Characterization Objective – Evaluate potential matrix diffusion issues associated with variations in hydraulic conductivity Type Hydrogeology Parameter Hydraulic Conductivity Subsurface Media Unconsolidated Subsurface Zone Saturated Data Quality All No associated notes.

95 Example #3 – Hydraulic Conductivity21 tools returned. Can we refine? No associated notes.

96 Example #3 – Hydraulic Conductivity (refined)No associated notes. Change data quality to QL 7 tools returned

97 ITRC Tools Matrix SummaryCharacterization objectives guide selection of tools Interactive tools matrix - over 100 tools with links to detailed descriptions A systematic tools selection process Select tools, implement work plan, evaluate results Align data gaps with characterization objectives, update CSM Repeat as necessary until consensus that objectives have been met No associated notes.

98 Training Overview DNAPL Characteristics Life Cycle of a DNAPL SiteIntegrated Site Characterization Plan Tools Selection Implementation Summary No associated notes. ISC-1, Chapter 4

99 Conducting Step 6: Implement investigationStep 7: Perform data evaluation and interpretation Step 8: Update CSM No associated notes.

100 Step 6. Implement InvestigationTime to conduct the investigation Go into field Use flexible plan Collect data Often concurrent with data evaluation (Step 7) No associated notes.

101 Step 7. Data Evaluation and InterpretationGain understanding of site Integrate all data types Generate collaborative datasets Multiple line of evidence Contaminant transport Storage Attenuation No associated notes.

102 Step 7. Soil and Groundwater Data Evaluation and InterpretationSource area concentrations remain elevated Depth PCE mg/kg Lab 0-2 3.25 Mobile 2-4 2.232 4-6 <0.37 6-8 3.298 8-10 11.5 10-12 0-2’ 21 Fixed Garage Dry Cleaner Gasoline Station Garage Case Example Garage Garage Vacant No associated notes. Residence Apartments 40 ft (approx.) Monitoring Well Garage Residence Soil Boring Result exceeds criteria Result does not exceed criteria

103 Step 7. Soil Vapor Data Evaluation and InterpretationGarage Residence Dry Cleaner N Depth PCE units Lab 3-4’ 3720 Mobile 4-5’ 2398 3800 Fixed Gasoline Station Case Example Vacant No associated notes. Apartments 40 ft (approx.) Monitoring Well Soil Boring Result below vapor screening level Result exceeds chronic vapor screening level Result exceeds sub-chronic vapor screening level Shallow soil vapor results

104 Poll Question When do you typically update your CSM at sites where you work? Whenever new data is collected When a remedial technology fails Whenever the CSM is determined to be inaccurate Every five years Never Poll Question No associated notes.

105 Step 8. Update the CSM Data collected from all phases of a project can be used As a project progresses, data needs shift In late phases, additional data collection often driven by specific questions ISC continues as the CSM evolves No associated notes.

106 Step 8: Dry Cleaners – CSM Update< vapor screening level > chronic vapor screening level > sub-chronic vapor screening level Garage Dry Cleaner Gasoline Station > soil/GW criteria < soil/GW criteria Garage Garage Garage Vacant 10 20 Depth (ft) Original vertically-delineated plume With additional data, the source area was found to extend west further than previously delineated Case Example Residence Apartments 40 ft (approx.) No associated notes. Monitoring Well Garage Residence Soil Boring

107 Integrated Site Characterization Benefits for Dry Cleaners SitesConfirmed need for residential indoor air evaluation and VI mitigation for commercial buildings Optimized data density in specific areas; avoided unnecessary / inconclusive data collection Accurately determined source zone and remediation target area Completed ahead of schedule; saved $50k of $150k budget (33%) Case Example No associated notes.

108 Training Overview DNAPL Characteristics Life Cycle of a DNAPL SiteIntegrated Site Characterization Plan Tools Selection Implementation Summary Understanding the subsurface behavior of DNAPLs is technically-challenging and methods for site characterization have evolved. The objective of this document is to describe the tools and resources that can improve the identification, collection, and evaluation of appropriate site characterization data to prepare more accurate CSMs. This guidance describes how, with the current understanding of subsurface contaminant behavior, both existing and new tools and techniques can be used to measure physical, chemical, and hydrologic subsurface parameters to better characterize the subsurface. The expected results of using this guidance are more accurate site-specific CSMs, which can then be applied in the ITRC Integrated DNAPL Site Strategy (ITRC 2011).

109 Summary Integrated Site CharacterizationPlanning Tools selection Implementation No associated notes.

110 Integrated Site Characterization is the Path ForwardToo many DNAPL sites are stalled or unresolved Examining DNAPL mobility in heterogeneous environments promoted better remedy selection Better characterization builds trust and confidence in site decisions Better characterization builds trust and confidence in site decisions: Stakeholder participation Risk mitigation; site restoration Cost optimization

111 Thank You 2nd question and answer break Links to additional resourcesFollow ITRC 2nd question and answer break Links to additional resources Feedback form – please complete Poll Question Links to additional resources: Your feedback is important – please fill out the form at: The benefits that ITRC offers to state regulators and technology developers, vendors, and consultants include: Helping regulators build their knowledge base and raise their confidence about new environmental technologies Helping regulators save time and money when evaluating environmental technologies Guiding technology developers in the collection of performance data to satisfy the requirements of multiple states Helping technology vendors avoid the time and expense of conducting duplicative and costly demonstrations Providing a reliable network among members of the environmental community to focus on innovative environmental technologies How you can get involved with ITRC: Join an ITRC Team – with just 10% of your time you can have a positive impact on the regulatory process and acceptance of innovative technologies and approaches Sponsor ITRC’s technical team and other activities Use ITRC products and attend training courses Submit proposals for new technical teams and projects Need confirmation of your participation today? Fill out the feedback form and check box for confirmation and certificate.