Tom Colligan, LHG

Associate Principal

Tom Colligan is a licensed hydrogeologist and geologist with more than 30 years of experience managing and conducting hazardous waste site investigations and cleanups for commercial and industrial clients. He is adept at implementing and managing all aspects of site investigations and feasibility studies, with particular expertise in conducting field investigations and evaluating the resulting site characterization data to identify practical and cost-effective remediation alternatives in accordance with Washington State Model Toxics Control Act (MTCA) and federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) regulations.

Tom’s technical expertise has been applied to sites contaminated with chlorinated solvents, creosote and coal tar, heavy metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, and polychlorinated biphenyls (PCBs) at defense installations, industrial facilities, and waterways and ports throughout the Pacific Northwest. He is particularly experienced in remediation of contaminated groundwater and soil using a variety of methods including enhanced reductive dechlorination, in situ chemical oxidation and reduction, soil vapor extraction, air sparging, dual phase recovery, barrier walls, thermal remediation, pump and treat, bioventing, land farming, excavation, capping, and natural attenuation. Tom has also worked on numerous projects involving stormwater source control and stormwater contaminant remediation. His understanding of industrial processes and his practical, cost-effective approach to project management enable him to provide exceptional environmental expertise and regulatory support to achieve client objectives. Tom holds a graduate degree in Geological Sciences from the University of Washington and an undergraduate degree in Earth and Space Science from Stony Brook University and is a licensed hydrogeologist in the State of Washington.