Manage "Transition Zone Characterization and Remediation & “The Passaic Gap” Series I"

Описание: One of the most challenging regimes for in situ remediation is a transition zone; this is a zone that separates the overburden from competent bedrock and is typically partially weathered bedrock, weathered bedrock, or saprolite. There is no better example of this geologic setting than the Passaic Formation- a mapped bedrock unit that is predominantly located in New Jersey, Pennsylvania, and New York states. As an example, in New Jersey, much of the historical manufacturing and industrial sector was situated above this geologic unit and, typically, their historical impacts are realized as volatile organic compounds (VOCs) in overburden, transition zone, and bedrock.

While most remediation efforts in the Passaic Formation have focused primarily on overburden impacts, and to a limited extent the competent bedrock, the transition zone is typically not well characterized or remediated. At AST, we call that transition zone the “Passaic Gap”. For many sites, this is the most problematic zone keeping a site from closure or monitored natural attenuation.

Yet, as many of our clients know well, AST has unlocked the secret to treating this geologic zone with specific approaches and equipment. This presentation will describe how to characterize the Passaic Gap, and other analogous formations, using both conventional and modern techniques, and design successfully and succinctly for high-energy injections. Considerations and planning during the characterization phase will work towards the intent to inject specific reactants utilizing high-capacity pumps, with deference to the necessary overburden and/or competent bedrock remediation efforts. Multiple case studies from the “Passaic Gap” setting will be reviewed, including in the second part of this webinar series a focus on a performance-based contract site with serious transition zone and overburden impacts, including dense non-aqueous phase liquid (DNAPL).