Geology & Investigations
Geology controls how and where contaminants move once they enter the ground. Determining soil and rock types and the flow of contaminants, water, and vapor through them dictates how a site is remediated.
Investigations take different forms, from collecting a few shallow soil samples by hand in a farmer’s field to installing multiple deep wells to conduct an extensive aquifer test; the right size of an investigation is one that answers the questions.
Investigation elements typically include:
- Identifying sample locations & media (soil, sediment, soil vapor, or groundwater).
- Selecting the right equipment to obtain the samples.
- Preparing a workplan for the regulator, including a health and safety plan.
- Implementing field work while minimizing its effect on ongoing site operations.
- Evaluating data obtained and interpreting the results.
- Preparing a report documenting the field work, with conclusions and recommendations based on the data.
All EnvApps investigations are performed under the direction of a professional geologist, hydrogeologist, or engineering geologist. Our field personnel make decisions onsite, adjusting project activities and expenditures to fit the latest findings and field conditions.
Example Projects:
Extensive Quick Turnaround Assessment - Completed 195 Geoprobe borings inside and outside a warehouse, and collected over 400 soil, 56 soil vapor, and 9 groundwater samples to assess the extent of chlorinated solvent impact. Extensive and high levels of PCE and vinyl chloride were found, along with hazardous concentrations of cadmium, lead, and copper. EnvApps also performed an indoor air quality assessment to determine the suitability for future occupancy. The final report (including a remedial action plan) was submitted to the client less than four months from project initiation.
Aquifer Testing & Hydrogeologic Modeling - Performed aquifer testing and hydrogeologic modeling to design an extraction well network for hydraulic control of a dissolved nitrate plume. The plume extended approximately one-mile down gradient by a quarter mile in width, with concentrations of up to 3,000 mg/L of nitrate.
Offshore Sediment Sampling - Prior to dredging and sea disposal operations, EnvApps sampled sediments at 25 stations at up to 45 foot depths from a vessel in Long Beach Harbor. The project included evaluation of existing sediment cap applied over previously dredged sediments.
Quick Site Closure - Obtained closure of a PCE-impacted dry-cleaner site from the LARWQCB within three months, including groundwater monitoring well installation, sampling, and reporting.
Expedited Assessment - Conducted an expedited (one month from contract signing to report submittal) assessment of a major oil company research facility prior to property sale and redevelopment for residential and commercial use. |
