Remedial Investigations, Feasibility Studies, and Corrective Action Plans

Remedial Investigation (RI)
At a certain point in the process of assessing site contamination, a final investigation phase is conducted that has the purpose of filling all remaining data gaps in creating a full picture of the contamination. Both the lateral and vertical extents of the contamination must be determined. For example, there may be a need to define one or more of the edges of a groundwater contamination plume by finding areas of no detectable contamination. The state regulator may be involved at this point, and may have also requested a few additional pieces of site data be collected.

Additional soil or groundwater chemistry information (e.g. dissolved oxygen and organic carbon content) may be valuable to collect at this point, so that different remediation techniques can be better evaluated. Because this is hoped to be the “final” investigation – or data collection – phase prior to remediation, it is often call the Remedial Investigation, or RI. The RI includes some level of Risk Assessment to identify contamination exposure risks.

Feasibility Study (FS)
Assuming an adequate amount of site data has been collected, and we feel confident in our Conceptual Site Model of the contamination, the Feasibility Study is an evaluation process that selects four to six or so potential cleanup solutions including No Action, and then submits each to a number of scoring, or balancing, criteria. These criteria are:

  • Effectiveness (considers the certainty that the remedy will work, the timeframe and reliability of success)
  • Long-term reliability (will the remedy maintain protection over the long term)
  • Implementability (what is the ease or difficulty of implementation; can the success be verified)
  • Implementation risk (is there a human health or environmental risk associated with the remedy)
  • Cost reasonableness (is the cost of the remedy proportionate to the benefits)

The conclusion of the FS is to assign scores to the remedy options, then make a recommendation based on the best score. At this point, the project stakeholders and regulator agree to a clean-up option.

Corrective Action Plan (CAP)
This is a more streamlined approach often used by Underground Storage Tank Programs and contains all site assessment information and details for remediation of the contamination. Remedial Action is designed and implemented.

Request a Bid