Jarrod P. Yoder, PG, LSP
Woodard & Curran, Inc.
Jarrod Yoder is an Associate Principal at Woodard & Curran. He has been working as a strategic environmental consultant with 20 years of practical industry experience working with national defense contractors, Superfund PRP Groups, the oil and gas industry, municipalities, and commercial/industrial clients. He specializes in project planning, assessment techniques, and the selection, design, and implementation of remedial technologies for releases of petroleum and hazardous materials. A majority of his experience includes sites with commingled recalcitrant contaminants, non-aqueous phase liquids, sensitive receptors, vapor intrusion, and property development. Throughout his career, Jarrod has been the project and technical manager for developing innovative alternatives for assessing and remediating soil and groundwater contamination and mitigating vapor intrusion concerns at sites in New England. He has directed and implemented numerous site investigations and remediation strategies with a proven track record for reducing project expenses and environmental liabilities. Jarrod is a past chairman for the Regulations Committee of the Licensed Site Professional Association where he provided technical comments and support for the development of regulations and guidance documents for remediation technologies and vapor intrusion in Massachusetts.
FLASH POSTER PRESENTER – Vapor Intrusion: Don't Hold Your Breath
Vapor Intrusion Mitigation and Source Area Reduction for Large and Active Buildings
With the continued emergence of vapor intrusion issues at large manufacturing plants, greater technical challenges are being faced with source identification/mitigation below buildings and designing and implementing effective remediation/mitigation systems for occupied buildings. The objective of this presentation is to provide a discussion of the remedial strategies, feasibility of implementing the remedial strategies, design considerations (vertical versus horizontal well remediation, locations, length of wells, etc.), and real-world data illustrating the effectiveness of horizontal well remediation versus vertical well remediation for vapor extraction and in-situ remediation below active manufacturing plants and occupied buildings.
The presentation will provide information regarding the need for strong remedial investigation and conceptual site model and detailed conceptual design for vapor mitigation and remediation below the building. Discussion of the factors influencing the design of the remedial strategy, building construction and operations, hydrogeology, plume characteristics and dynamics, exposure pathways (particularly indoor air) and subsurface improvements (utilities, footings, etc.) will be provided. Detailed design of air flows, extraction leg locations and lengths, and extraction points will be examined. The critical use of remote sensing and selective demolition/observation before and during installation will also be detailed.
Case Study Details: Horizontal drilling was employed to install more than 3,500 linear feet of horizontal wells that were designed to extract vapor for vadose zone source reduction, vapor intrusion mitigation, and in-situ injections to reduce residual mass in the saturated zone below the building. The remedial strategy effectively eliminated the vapor intrusion risk, reduced residual mass of volatile LNAPL, and reduced PCE, TCE, and TCA concentrations in source areas below a 600,000+ s.f. industrial building. Site logistics (building configuration, occupancy, utilities) necessitated blind installation of horizontal wells. Depth of utilities below the building slab in many locations created challenges that needed to be managed during installation in active manufacturing areas. Remote sensing and mapping techniques were used to plan the extraction well routes, and air flow design was modified to account for sometimes eccentric routing of pipes and the relatively long horizontal well lengths that were required to achieve remedial objectives.
Aerobic Bioremediation of Recalcitrant Organic Solvents in Densely Populated Areas
Identification of recalcitrant organic solvents like PCE and TCE in the subsurface of many urban sites often requires an evaluation of innovative treatment technologies to meet remedial goals. Receptors, buildings, and utilities, limit the use of intrusive methods or oxidizers. In-situ bioremediation is one technology that is capable of degrading solvents in densely populated areas.
Anaerobic processes have been documented to take longer than aerobic processes and it can be difficult to maintain microbial populations and nutrients/electron donors necessary to support biological processes. The degradation of solvents through aerobic cometabolic processes creates oxygenase enzymes that form an epoxide, which converts ethenes into organic acids. The enzyme is produced as the microbes digest simple-chain sugars. This approach includes “low volume” injections of pathogen-free microbes that have metabolic diversity and the ability to pass plasmid encoding between strains.
Case studies with aerobic processes conducted by the author achieved remedial goals faster and have less risks (chemical exposure and safety) to nearby human receptors, utilities and buildings. Reduction of solvents by 50 to 90% within 6 months was achieved with limited rebound. This presentation will describe the approach, design, implementation and real world data from 2 case studies conducted at urban sites and provide data from other similar sites.