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Guidance Resources

This web page was developed to promote a consistent and informed approach for Michigan Department of Environment, Great Lakes, and Energy (EGLE) for the volatilization to the indoor air pathway (VIAP). This document is a ready-reference tool for anyone trying to address the VIAP in Michigan. The information contained in this document is drawn from existing manuals, various reference documents, and a broad range of colleagues with considerable practical experience and diverse educational backgrounds. The information provided on these web pages are available as a technical reference to assist any party conducting investigations and evaluating the VIAP to support risk management decisions.

The Guidebook

The Guidebook is developed into different topic specific volumes so that when the document is completed, it is easier to identify where the information on a specific topic may be found.

NOTE: The use of the information in these volumes requires that the data collected be representative of the actual conditions and for the purpose that it is intended. It is the user’s responsibility to understand the strengths and weakness of the sampling method prior to utilizing and that the resulting data is what the decision is based on.

How to use this guidance document

Each volume this is intended to be a stand-alone document, it references material that is contained in other volumes that directly relate to the VIAP. Users of this guidance should become familiar with each volume and how it may impact the investigative approach described.

NOTE: Currently there are several volumes being drafted. Prior to completing, each volume will be released as a draft that EGLE will receive comments on. The times frames, forms, more information, and the process that EGLE will use can be found on each volume’s landing page. Once completed, Volume 7 will document any modifications from the final version.


  • Volume 1 – Volatilization to the Indoor Air Pathway (VIAP) Overview – Under Development
  • Volume 2 – Investigation Methods for the Volatilization to the Indoor Air Pathway (VIAP) – Under Development
  • Volume 3 – Investigation Approach for Volatilization to the Indoor Air Pathway (VIAP) – Under Development
  • Volume 4 – Investigative Approach for Petroleum Volatilization to the Indoor Air Pathway (VIAP)Public Review Draft
  • Volume 5 – Response Activity – Under Development
  • Volume 6 – Volatilization to the Indoor Air Criteria – Under Development
  • Volume 7 – Updates – Under Development

These web pages are explanatory and outlines an approach to demonstrate compliance when the generic criteria under Part 201, Environmental Remediation, of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended (NREPA), and Part 213, Leaking Underground Storage Tanks, of the NREPA, do not apply. By following the process outlined in this document, a party can achieve the performance standards required by Part 201 and Part 213. The process outlined in this document is not the only means by which a party can meet the requirements of Part 201 and Part 213 and is provided as a reference tool and not as a mandatory requirement. .

NOTE: Site conditions, contaminants, and geology may require modifications of this approach. The methods outlined in this document will produce reliable data that can support the various decisions required throughout the environmental process.

A policy guidance document cannot establish regulatory requirements for parties outside of the EGLE. It is explanatory and provides direction to staff, guidance to the regulated community, and consistency in enforcing the NREPA, but does not have the force and effect of law and is not legally binding on the public or the regulated community. These web pages do not establish or affect the legal rights or obligations for management of the VIAP. It does not have the force or effect of law and is not legally binding on the public or the regulated community. Any regulatory decisions made by EGLE will be made by applying the governing statutes and Administrative Rules to relevant facts.