Hazardous Materials Investigations

Phase I/II Environmental Site Assessments

Our hazardous materials team specializes in the preparation of Phase I Environmental Site Assessments (ESAs) to support environmental review of projects under CEQA/NEPA. The purpose of these assessments is to identify contaminants of potential concern in soil, groundwater, soil gas, and/or building materials that could pose an environmental or human health risk. Typical projects include major transportation improvements (see below) and infill and Brownfield redevelopment. Our staff are thoroughly familiar with the contaminants of potential concern in urban and rural environments and can recommend measures to minimize potential effects to the project cost, scope, and/or schedule.


Based on the findings of the Phase I ESA, Baseline performs Phase II site investigation to evaluate the chemical quality of soils and groundwater to determine future management and/or remediation options. We handle all aspects of the investigation, including oversight of drilling operations (when needed), traffic control, permitting, and laboratory analysis of soil and water samples. Baseline geologists and engineers also have experience with site remediation, such as soil excavations, tank removals, chemical injections, and soil vapor extraction.  

Transportation Improvement Projects –

Initial Site Assessments and Investigations


Baseline has worked on numerous highway and roadway improvement projects in the Bay Area and is familiar with Caltrans procedures. Our hazardous materials services for transportation projects include the evaluation of contaminants of concern in soil (e.g., aerially-deposited lead), groundwater, and structural materials (e.g., lead-based paint). Soil analytical results are often statistically analyzed prior to excavation to evaluate potential risks to human health and to minimize the generation of hazardous wastes for offsite disposal. By working closely with Caltrans and local transportation authorities, Baseline has developed a unique knowledge related to large highway/roadway improvement projects and can implement assessment and investigation activities in a timely and cost-effective manner.