Significant changes to the Massachusetts cleanup regulations, known locally as the “MCP,” became effective June 20, 2014. As we described in our April 2014 alert, these changes substantially revised numeric standards and closure requirements and modified the assessment and remediation of sites with vapor intrusion, historic fill, and nonaqueous phase liquid. Since then, the Massachusetts Department of Environmental Protection (MassDEP) has been developing guidance materials to assist with implementation. These guidance documents touch on the most important changes in the regulations, and provide insight into anticipated implementation challenges:

New MCP Questions and Answers. In June 2014, MassDEP issued “New MCP Questions and Answers” relating to the 2014 revisions to the MCP. These highlight some areas of uncertainty in interpreting the new requirements. If your project involves remedial additives near sensitive receptors, historic fill,  nonaqueous phase liquid (NAPL), or vapor intrusion issues, this guidance may contain useful clarifications. In addition, the guidance discusses transition requirements. Of particular importance, some sites that have open Immediate Response Actions must now be classified as Tier I sites.

Draft Guidance on Assessment and Closure of Sites with Light NonAqueous Phase Liquid (LNAPL). During the summer, MassDEP issued draft guidance on the 2014 changes to the MCP relating to LNAPL and its revised understanding of how LNAPL moves in the environment. This guidance is intended to assist LSPs to investigate, assess, understand and address the presence and migration of LNAPL at sites under the 2014 MCP. The guidance includes a simplified approach to demonstrating compliance with the LNAPL performance standards, as well as information that could be used to support alternative approaches. MassDEP has opened an informal comment period on the draft guidance, which ends October 20, 2014.

Note, the 2014 MCP amendment substantially changed reporting requirements for NAPL. In the New MCP Questions and Answers guidance described above, MassDEP clarified that if an existing, known NAPL condition triggers 2-hour or 72-hour reporting then it must be reported within that time frame unless that condition already was reported as a 2-hour or 72-hour condition. Under this interpretation, many existing sites triggered additional reporting as of the effective date of the regulations. If you are working on a NAPL site and you have not yet evaluated this provision, it would be appropriate to evaluate it now.

Draft Guidance on Notices of Activity and Use Limitations. MassDEP has issued draft guidance on implementing Notices of Activity and Use Limitations (AULs). This guidance addresses both when an AUL is appropriate and implementation issues. Among the issues being clarified are when a survey is necessary and what should be included in the new AUL Narrative section. MassDEP has opened an informal comment period on the draft guidance, which ends September 22, 2014.

Best Management Practices for Gardening. One of the changes made in the 2014 MCP is to allow elevated levels of contamination to remain in place without requiring an AUL when the contamination could lead to significant risks to human health due to home gardening. Instead of requiring an AUL, MassDEP now requires that the Permanent Solution recommend that homeowners follow Best Management Practices (“BMPs”) when gardening to reduce these risks. MassDEP has issued draft guidance on these BMPS, which includes use of raised beds. MassDEP has opened an informal comment period on the draft guidance, but has not announced a due date for comments.  We anticipate that comments will be due this fall.

Draft Vapor Intrusion. MassDEP has indicated that it will issue guidance on addressing vapor intrusion under the revised MCP, but it has not yet been issued. MassDEP has indicated that it plans to issue the guidance in draft and provide a public comment period.