Where did the Amendment Go? Using Multiple Techniques to Monitor Injection Effectiveness
The in-situ remediation industry has advanced significantly over the past decades with the introduction of new remedial amendments and improved delivery techniques. However, despite these advances in-situ remediation, field applications continues to face challenges with how to ensure proper delivery of amendments in the subsurface. It has been demonstrated that in-situ amendments have a tendency to migrate along preferential, high conductivity pathways, yet contamination from historical contamination releases may be located in low permeable zones. To understand and overcome these challenges, advancements in real-time field monitoring of in-situ injections are required. Vertex has completed hundreds of in-situ injections across Canada and as field practitioners have experimented with many approaches for evaluating amendment delivery. The objective of this talk is to present recent advances in the field techniques to monitor the effectiveness of in situ injection delivery.
An overview of field monitoring techniques is presented including injection parameters, pressure signatures, tracer tests, adjacent well monitoring, high resolution sampling, soil core assessments, and high resolution characterization verification. Field data are presented from two (2) case studies where a variety of field monitoring techniques were implemented to understand delivery and improve injection effectiveness. Both sites involved the injection of amendments using a grid of interlocking, depth-targeted, temporary injection intervals for the remediation of chlorinated solvent impacts.
The presentation summarizes principles for the effective field monitoring of in situ injections, including the benefits and limitations of various field monitoring techniques. An overview of cost implications for the various techniques is also presented.