Hydrogeological Investigations and Remediation Projects
Oilfield Production Facility
Rio Blanco County, CO
Hydrocarbons were identified seeping into a perennial stream that resulted in the state regulatory agency issuing an administrative order to determine sources for the seeps, as well as the extent of impact to groundwater and surface water. Direct push technology was employed to collect groundwater samples, which were analyzed in the field to map the contaminant plume and identify potential sources. Monitoring wells were installed to assess phase-separated hydrocarbon (PSH), and demonstrate plume stability. Air injection was proposed as the remediation technology to treat the dissolved-phase plume, while an eductor-pump was proposed to address PSH recovery.
Natural Gas Pipeline Spill Assessments
Lea County, NM
Subsurface investigations were performed at seventeen spill sites involving the release of natural gas liquids (NGL) from underground pipelines. Investigations were conducted using direct-push, hollowstem auger and rotary drilling techniques to collect soil samples to define the vertical and horizontal extent of impact. Soil samples were analyzed by field and laboratory methods, and proposed remediation ranged from noaction to blending impacted soil with clean soil to achieve recommended standards.
Oil and Gas Production Facility Assessment and Closure
Moffett County, CO
A complaint filed with the state oil and gas regulatory agency alleged potential impacts to soil and groundwater from a plugged oil well located in an environmentally sensitive area. Direct-push sampling technology was employed to collect groundwater samples from a shallow aquifer, which was analyzed in the field to efficiently map the contaminant plume, and reduce laboratory costs. The extent of groundwater impact was determined, and a risk assessment was performed to allow the limited benzene plume to naturally attenuate. Soil impacted above the regulatory threshold was treated offsite. No further action was required by the state regulatory agency.
NPDES Discharge Pit Closure and Groundwater Assessment
Big Horn County, WY
Several pits were permitted under the National Pollution Discharge Elimination System (NPDES) and were used as oil and gas separation pits. A subsurface investigation was performed using direct-push technology to assess potential impacts to soil and shallow groundwater, and concluded a groundwater impact to a limited area. A risk assessment was performed and natural attenuation selected as a remedy. Site closure was granted by the regulatory agency.
Methanol Spill Investigation and Remediation
Lincoln County, WY
This project involved delineating the extent of a methanol release at an oil and gas production facility. A soil gas survey was performed using directpush technology to initially assess the extent of shallow impacts, and deeper impacts to soil and rock were evaluated using hollowstem auger techniques. The limit of impact was defined, and a corrective action plan (CAP) was developed to comply with the Resource Conservation and Recovery Act (RCRA). Impacted soil exceeding the state mandated threshold was excavated and treated using low temperature thermal desorption technology.