The Massachusetts Department of Environmental Protection (MassDEP) is proposing some significant changes to the Massachusetts Contingency Plan (MCP).  The MCP is the regulation which governs the assessment and remediation of contaminated sites in Massachusetts.

The proposed changes to the MCP encompass these 5 areas:

Permits, Tier Classification and the Numerical Ranking System – The MassDEP proposes eliminating Tier permits and using a much simplified process to classify sites as either Tier I or Tier II based on whether disposal site conditions meet any one of 4 criteria.

Activity and Use Limitations – The MassDEP proposes eliminating the AUL Opinion from the Notice of AUL and allowing the use of Notices of AUL at federal Superfund sites.

Vapor Intrusion and Site Closure Provisions – This is the area with the biggest changes.  The proposed changes clarify when a site with vapor intrusion can be closed and provides a clear pathway to close sites with an active subslab depressurization system (used to mitigate vapor intrusion).  Site closure categories and terms will be simplified to include either a Permanent Solution or a Temporary Solution.  Permanent Solutions will either be a Permanent Solution with Conditions or a Permanent Solution with No Conditions.  A Permanent Solution with Conditions will include sites with AULs and subslab depressurization systems.

Non-Aqueous Phase Liquid and Source Control – The MassDEP proposes eliminating the Upper Concentration Limit for NAPL of 1/2-inch and using more specific performance standards to demonstrate source elimination or control, not just for NAPL but for all oil and hazardous materials.

Numerical Standards and Risk Characterization – The MassDEP proposes changes to select numerical standards (Reportable Concentrations and Method 1 Standards) to reflect current information about chemical properties and toxicity.

“An LSP Opinion” will be an occassional feature here in the Omni blog.  We’ll talk about the Massachusetts Contingency Plan along with the roles and responsibilities of Licensed Site Professionals.  Next time, we’ll discuss some of these proposed MCP changes in more detail.

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