Tier 2 Assessment

The purpose of Tier 2 assessment is to collect additional site-specific data and, with the use of Tier 2 fate and transport modeling, determine what actual and potential receptors could be impacted by chemicals of concern.

A Tier 2 Site assessment must be conducted and a Site Cleanup Report submitted for all sites when any of the following conditions occur:

  • Free phase petroleum product is present at the site.
  • The site owner or tank owner/operator has decided to bypass the Tier 1 assessment and go directly to the Tier 2 assessment phase.
  • A pathway has failed the Tier 1 assessment.
  • During drilling, bedrock was encountered before groundwater.
  • Explosive vapor levels were measured during a Tier 1 assessment or recent investigation of the site.

Tier 2 Guidance along with application will help you to fill out the assessment report.The application will perform the same functions as the former software in essentially the same ways. The Tier 2 SMR Version 2.51 User’s Manual may also be helpful.

Web-Based Risk Based Corrective Action (RBCA) Application

The web-based application will be used for new and revised Tier 2 Site Cleanup Reports, and Site Monitoring Reports.This does not apply to non-granular bedrock and granular bedrock sites. Please review the FAQ document posted on the DNR UST web page prior to using the application for RBCA purposes.

The Tier 2 Site Cleanup Report Guidance has been updated.  This update of the Tier 2 Guidance was undertaken in an effort to make the document more user-friendly and to better reflect current practice.  You will find most items unchanged; however, some of the updates include:

  • Tier 2 Guidance is now a searchable document in a user-friendly format with embedded links.
  • New guidance on surface water risk assessment.
  • The stabilization time for soil gas sampling (Option 2) has been changed to 24 hours.  This change will take effect 60 days after the new Tier 2 Guidance is posted to allow for projects already in progress.   This is effective September 6, 2015.
  • A section on diving plumes and free product has been added.

Tier 2 Guidance

Tier 2 Report Form - The pages for the Tier 2 Report which are not printed from the application are now fillable PDF forms.