Department of Health Seal

TGM for the Implementation of the Hawai'i State Contingency Plan
Section 5.11


The field investigation team should restore the investigation site once soil sampling and associated field investigation is completed to as close to pre-investigation condition as possible. This includes, but is not limited to the following:

  • Demobilization of all equipment (e.g. drill rigs);
  • Removal of field-related structures (e.g. temporary field trailers);
  • Proper management or disposal of IDW;
  • Repair of structural changes made to the site as a result of investigation (e.g., patching or resurfacing of concrete/asphalt surfaces cut for borings).

In particular, after any subsurface soil sampling is completed and if no other field investigation activity is to be conducted within a boring location (e.g., monitoring well installation, product removal) the borehole must be securely closed and sealed. If not properly closed and sealed, boreholes may otherwise act as a conduit for contamination. All procedures and materials for sealing boreholes should be outlined in the SAP for review prior to initiation of the field investigation. The procedures for closing and sealing boreholes recommended by the HEER Office follow those for abandoning and closing monitoring wells, as described in Section 6.2.5.

In some instances where follow-on activity at the site is planned but not yet initiated (e.g., subsequent soil removal) or if a potential exposure pathway or other hazard exists (e.g., unstable structure), retaining some structures such as temporary fencing or signage onsite is appropriate and should be implemented and documented in the site investigation report.

The HEER Office strongly recommends that site restoration as close as possible to pre-investigation conditions be documented in photographs, and the photographs be included as part of the site investigation report.