Site Assessment and Investigations

EA’s projects have included numerous investigations and characterization assessments for soil, soil vapor, groundwater, and surface water involving solvents, metals, pesticides, 1,4-dioxane, petroleum hydrocarbons/fuels, uranium, hexavalent chromium, perchlorate, polychlorinated biphenyls (PCBs), fertilizers, explosives, radionuclides, and emergent chemicals. The projects have included assessments and investigations under the Resource Conservation and Recovery Act (RCRA), Federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), state Superfund, and state, county and local governments. Projects have ranged in complexity from simple focused evaluations at small sites to sites with multiple potentially responsible parties spanning many square miles

 

Soil and Groundwater Contamination Studies 

EA’s engineers are extremely knowledgeable in proven and innovative assessment methods to determine the quality of soil, soil vapor, ambient air, groundwater, unsaturated zone pore fluids, and surface water. EA has designed and executed subsurface characterization approaches from minimally intrusive investigations to full RCRA/CERCLA-based remedial investigations. These investigations delineate the nature and extent of environmental impacts in soil, soil vapor, groundwater and/or surface water, including dense and light non-aqueous phase liquids. EA staff utilizes targeted information collection methods to reduce long-term commitments and often unnecessary data collection efforts.   

Emergent Contaminants

Emerging contaminants are becoming a greater concern for many states in the protection of their groundwater supplies. Locations such as airports, highly industrialized areas, and groundwater recharge facilities are likely sites that will require groundwater monitoring to stay ahead of any potential future contamination. EA’s staff have evaluated existing assessments, remediation approaches, and former industrial sites for compounds including hexavalent chromium, perchlorate, N-Nitrosodimethylamine (NDMA), 1,4-dioxane, and per-and polyfluoroalkyl substances (PFAS). Key activities have included evaluation of former site operations and potential for use, storage, and discharge of these contaminants at industrial facilities in California and preparation of PFAS Investigation Work Plans pursuant to California Water Code Section 13267 and 13383 Orders administered by the California State Water Resources Control Board (SWRCB).

Vapor Intrusion

EA’s staff are well versed in assessing vapor intrusion potential through screening level evaluations, predictive models, and empirical data sets. EA has implemented many indoor air assessment projects for industrial, commercial, and residential properties under the oversight of Regional Water Quality Control Board (RWQCB), Department of Toxic Substances Control (DTSC), and U.S. Environmental Protection Agency (EPA). EA’s staff have prepared assessment work plans incorporating use of soil vapor, sub-slab, and indoor air sampling programs.

Conceptual Site Model and Numerical Modeling

EA staff have developed many conceptual site models (CSM’s) for projects in multiple states to support site assessment and remediation strategies, fate and transport models, human health and ecological risk assessments, vapor intrusion evaluations, and groundwater basin water supply studies. Many of the CSM’s have been reviewed by oversight agencies including EPA, DTSC, RWQCB, etc. as well as technical peer review committees. The CSM’s have included complex weathered/fractured bedrock systems, epikarst/karst systems, complex structural deformation of sediments, and regional groundwater basins covering areas of over one hundred square miles.

Groundwater, Vadose Zone and Surface Water Modeling

EA’s engineers have prepared and managed groundwater flow, vadose zone, and surface water flow contaminant transport models for numerous projects in various phases at CERCLA, RCRA and state-lead sites. EA has extensive experience modeling contaminant conditions for soil, groundwater, and surface water while assessing their fate and transport in these media. This experience has taught us the importance of matching the model and overall strategy to the goals of the modeling effort at the beginning of the process to save money and time. Often, simple models can achieve the project objectives but when more complex models are necessary, EA has the experience to identify the model that will produce the most accurate results.

Public Participation/Community Outreach

EA staff have prepared public participation plans, community surveys, community notices, responses to frequently asked questions and to community inquiries. EA has also established document repositories and toll-free information hot-lines for the public. In addition, EA has prepared and transmitted public outreach communications to state senators, legislators, governors, and other state and local officials, community and environmental groups, and nearby residents.

Forensic Investigations

EA offers regulatory and legal support services to our clients for a variety of environmental programs. Our licensed professional engineers and professional geologists also perform forensic investigations and provide litigation support to clients and their insurers on a host of construction-defect related issues. Using sound science and engineering, we advocate on behalf of our clients in the public, regulatory, and legal arenas.

 

Site Assessment and Investigation Services:

Engineering & Design
  • Site civil design
  • Structural design
  • Hydraulics and hydrology
  • Geotechnical design
  • Geologic analyses, geologic hazards
  • Hydrogeology, geochemistry
  • Forensic studies, litigation support
  • Feasibility analyses, costing
  • Construction management
Environmental Monitoring & Compliance
  • Permitting, compliance
  • Vapor assessment and mitigation
  • SPCC and SWPPP plans
  • Remedial investigations and site characterization
  • Groundwater remediation
  • Feasibility studies
  • Stormwater management
  • Health & safety
Construction Materials Testing
  • Field engineering
  • Soil, concrete, asphalt testing
  • Quality assurance/quality control
  • Geotechnical laboratory testing

Site Assessment & Remediation

We provide cost-efficient, risk-based solutions for rehabilitating contaminated properties.