Enviro-Core - A Dual-Tube Direct Push System For Rapid Site Characterization

Enviro-Core® is a patented dual-tube or “cased” soil coring system that uses small-diameter<br>temporary drive casing to prevent the probe hole from collapsing between sampling runs. The<br>small-diameter drive casing and inner sample barrel are simultaneously pushed, pounded, or<br>vibrated into the ground. Soil cores are collected in liners inside the sample barrel. After being<br>advanced, the sample barrel is retrieved, while the drive casing is left in place to prevent the<br>borehole from collapsing. The drive casing ensures that subsequent samples are collected from the<br>targeted interval, rather than potentially contaminated slough from higher up in the probe hole. The<br>Enviro-Core system is most commonly used with portable sampling rigs that combine percussion<br>hammer and high-frequency vibration to advance the tool, although the system can be used with any<br>direct push (DP) sampling vehicle or conventional drilling rig. The design of the dual-tube<br>sampling system allows consultants to collect depth-discrete soil gas samples, groundwater samples,<br>and install small-diameter temporary or permanent monitoring wells. The system facilitates<br>retraction grouting, the most effective method of sealing DP probe holes.<br>The Enviro-Core® system was used during an accelerated environmental site investigation at<br>Alameda Naval Air Station in Alameda, California. The site geology and contaminant plume were<br>quickly defined in three dimensions, providing the design data necessary to install an experimental<br>in situ funnel-and-gate remediation system.