Benefits of Laboratory Treatability Studies in Support of Full-Scale Design for In Situ Remedies Michaye McMaster Geosyntec Consultants Sandra Dworatzek SIREM Lab October

Bottom Line Up Front – What are the Benefits  Can evaluate multiple remedial options prior to field implementation  Obtain site specific data to confirm technology can work for your site/compounds  Studies are flexible allowing changes “on the fly” and you are not dealing with field logistic challenges  Incremental risk taking between lab study and field  $ - lab work is typically less costly than field studies

First - Know where you are 1 Source On 2 DNAPL Redistribution 3 Distribution and Aging 4 DNAPL Depletion 5 Back Diffusion and Desorption

Then Make a Plan 4 Follow NRC 2005

What is Attainable The Conceptual Site Model (CSM) or Site Conceptual Model (SCM) should be developed first 1. Are there enough data to select technologies?  Treatment  Flux reduction  Longevity reduction  Containment  Flux reduction

Selecting Remedies The Conceptual Site Model (CSM) or Site Conceptual Model (SCM) should be developed first 1. Are there enough data to select technologies?  Treatment  Flux reduction  Longevity reduction  Containment  Flux reduction 2. Are there enough site specific data to select technologies? REMEDY SELECTION

Design and Implement The Conceptual Site Model (CSM) or Site Conceptual Model (SCM) should be developed first 1. Are there enough data to select technologies?  Treatment  Flux reduction  Longevity reduction  Containment  Flux reduction 2. Are there enough site specific data to select technologies? REMEDY SELECTION 3. Are there enough data to design and implement?

Technology Evaluation Chemical Oxidation Persulfate Permanganate Percarbonate Peroxide (Fentons) Ozone Chemical Reduction Granular, micro and nano scale zero valent iron Zero valent zinc, zero valent magnesium Other reduced iron minerals (e.g., siderite) Other Substrates (e.g., mulch) Bioremediation Aerobic Anaerobic Cometabolic Abiotic - Mediated Thermal ERH TCH STAR

What Compound Classes Can Be Evaluated  Chlorinated solvents (PCE, TCE, TCA)  Petroleum hydrocarbons (BTEX)  Pesticides (lindane)  Metals (selenium chromium)  sVOCs (naphthalene)  PAHs  PCBs C C C C C C Cl H H H C C C C C C H H

Oxidants Various oxidants:  Catalyzed hydrogen peroxide  Ozone  Permanganates  Persulfate  Solid phase peroxygens Testing includes:  Natural oxidant demand  Oxidant reactivity with contaminants  Activation chemistry

Bio/Treatability Studies CategoryTechnologyExample Target Contaminants Aerobic Oxygen Addition Nutrient Addition Petroleum Hydrocarbons, Pesticides Anaerobic Electron Donor Addition Chlorinated Solvents, Perchlorate, Oxidized Metals, Explosives, Nitrate Bioaugmentation (KB-1 ® / KB-1 ® Plus) PCE, TCE, DCE, VC and 1,2-DCA Chlorinated ethanes and methanes such as 1,1,1-TCA, carbon tetrachloride and chloroform CFC-113 Electron Acceptor AdditionPetroleum Hydrocarbons CometabolicGas inFusion 1,4-Dioxane, NDMA, Chloroform, TCE, DCE, VC, MTBE, Creosote, >300 different compounds Abiotic Natural Attenuation Reduced Metals Chlorinated solvents, Oxidized metals,

Most Common Approach Batch Microcosm Treatability Testing  Batch reactors constructed using site materials (soil, sediment or rock, and groundwater)  Monitor contaminant reduction over time  Customize treatment variables to meet site specific needs

Column Treatability Testing  Use site soil, sediment or reduced metal packed into columns  Pump groundwater through columns  Monitor contaminant reduction along flow path of column  More realistic to in situ flowing conditions – simulate mass transfer conditions and geochemical gradients in the aquifer  Can to Bio or Chemical

Column Treatability Testing  ZVI PRBs are a proven remedial technology for treatment of chlorinated solvent plumes  Simulate groundwater movement through a PRB  Evaluate key PRB design parameters including:  Degradation half-lives and assessment of breakdown products  PRB residence time  PRB design thickness  Treatment longevity, potential for passivation and fouling of ZVI  Product selection Reduced Metals Testing

Costs Batch Tests  pH buffering  Oxidant NOD  Reduced Metals Batch tests  Oxidant treatability  Biotreatability Column Tests  ZVI/reduced metals  Bioremediation Increasing cost

Where Do You get the job done??? Commercial Labs  Known Commodity  More Standardized Protocols  Local? University Researchers  Good place to start  Local access  Collaboration drives innovation  Results may not be as ‘acceptable’ to stakeholders Joint Ventures – Between Commercial Labs and University Researchers

Conclusions  Lab treatability studies allow for evaluating multiple remedial options prior to field implementation  Obtain site specific data to confirm technology can work for your site/compounds  Studies are flexible allowing changes “on the fly” and you are not dealing with field logistic challenges  Incremental risk taking between lab study and field  $ - lab work is typically less costly than field studies

Questions “If you don’t know where you are going you might not get there.” – Yogi Berra