Site Investigation
A comprehensive site investigation, along with risk assessment, is critical to identifying the nature and extent of contamination, the potential source(s), and in development of a cost effective remedial action. ETG utilizes a phased approach for site assessment and characterization, and provides a wide spectrum of hydrogeological, air quality, soil gas, and applicable investigation services tailored to the specific needs and objectives of each client and their site(s). ETG always completes site investigations with a focus on the likely interim and final remedial actions that will be required for the site. Site investigation work plans are developed with input from both risk assessors and remediation personnel. This results in site investigations that more efficiently gather data for completing a risk assessment and selecting the appropriate remedial action.
ETG personnel have performed site assessments and contaminant characterizations for private clients, utilities, and local and federal agency clients on large and small projects throughout the United States and Canada. ETG personnel have performed over 200 groundwater investigations for chlorinated solvents, heavy metals, nitrates, nitrites, and phosphates, and petroleum hydrocarbon contaminated sites. ETG is experienced with investigating and remediating both anaerobic (reductive dehalogenation) and aerobic aquifers for tetrachloroethene (PCE) and daughter products. ETG has worked with the United States Environmental Protection Agency (USEPA) sub-slab vapor intrusion guidance and State guidance for soil gas evaluation, and has completed numerous sub-slab soil gas sampling and indoor air quality investigations.
ETG frequently conducts investigations using a variety of techniques, including the following: borings and monitoring wells installed with direct-push, hollow-stem auger, air-hammer, air rotary, and sonic drilling rigs; single and multiple completion monitoring wells, low-flow groundwater sampling; and soil gas sampling utilizing dedicated vapor probes and direct-push techniques of both truck mounted direct-push, and hand-held rotary hammers.
ETG develops quality assurance/quality control (QA/QC) procedures specific to each project in an effort to limit the introduction of error into project data. Data quality objectives will be developed appropriate to each project site. Laboratory and field data are reviewed to verify that sampling and chain-of-custody procedures were followed, complete and accurate laboratory reports were prepared, holding times were met, quantification limits did not exceed established values, and that data quality objectives were met.
EXAMPLE PROJECTS BY GEOGRAPHIC AREA