AST Environmental’s overburden characterization approach fills those gaps with quantitative, high-resolution soil and groundwater data. Soil samples from both the unsaturated and saturated zones are analyzed for speciated volatile organic compounds (VOCs) and total mass fraction contaminants, including total petroleum hydrocarbons (TPH). With no-cost analytical services of the RPI Project Support Laboratory, this dense dataset refines the CSM and drives faster, more cost-effective remediation strategies.

Closing Data Gaps in Groundwater Profiling

Traditional monitoring well construction—long well screens designed simply to “make water”—often masks vertical contaminant gradients and aquifer variability. This practice, combined with sparse soil sampling above and below the water table, leaves major blind spots in the CSM.

AST solves this problem with discrete vertical profiling of overburden groundwater, enabling us to identify contaminant concentration changes and geological heterogeneity. During high-density soil sampling, we install:

• Short-interval screens (<5 ft) at selected depths within a common borehole using ½–1 inch PVC screen and riser casing
• Nested clusters of up to three separate casings with vertically offset screens in the same borehole
• Stainless steel screen-point samplers (hydropunch) to reduce costs and increase on-site efficiency without sacrificing quality

Groundwater samples from yielding intervals are sent to the RPI Project Support Laboratory in Golden, CO for both speciated and total mass fraction analysis.

High-Volume, High-Resolution Sampling

Every Remedial Design Characterization (RDC) is a collaborative effort with the consultant to refine the CSM. On average, we collect 150 soil and groundwater samples per RDC. For large contaminant plumes, we have collected and analyzed over 1,000 samples—producing the high-resolution datasets needed to accurately map contaminant distribution and guide successful in-situ remediation.