Groundwater Professional Bulletin Board

Plume Maps

This note updates the guidance concerning what contamination "plume maps" need to be submitted in a Tier 1 or Tier 2 when chemical of concern concentrations are less than action levels. The changes are in bold print:

• A map must be submitted for any chemical of concern that exceeds action levels.
• A benzene map must be submitted regardless of concentration.
• A TEH map must be submitted, regardless of concentration, if TEH was included in the site sampling. The exception to this is TEH-Waste Oil in soil. TEH-Waste Oil in soil maps are not required.

The above applies even if an SCR has been previously approved for the site. Maps must be submitted if replacement soil borings and/or soil gas points have been installed.

Please contact Elaine Douskey at (515)281-8011 or elaine.douskey@dnr.state.ia.us if you have any questions.