An LSP’s Opinion – MassDEP’s Similar Soils Provision Guidance

Under the Massachusetts Contingency Plan (MCP; 310 CMR 40.0000), there’s 4 basic criteria that must be met in order for a Licensed Site Professional (or LSP) to transport soil from a disposal site (I.e., a hazardous waste site) without prior notice or approval from the Massachusetts Department of Environmental Protection (MassDEP).  These 4 criteria are:

1. The managed soil must not be a hazardous waste under state or federal regulations.
2. The managed soil must have concentrations of oil or hazardous materials less than their associated Reportable Concentrations.
3. The managed soil must not create a condition at the receiving location which would require notification to the MassDEP (i.e., soil acceptable for use at an industrial site being reused at a residential site).
4. The soil at the receiving site must not have contaminant concentrations that are “significantly lower” than the contaminant concentrations in the soil being brought to the receiving site.

These criteria are specified at 310 CMR 40.0032(3).

In October 2013, the MassDEP issued the Similar Soils Provision Guidance.  The guidance is to clarify the last bullet above – that is, at what point does the soil at the receiving site have “significantly lower” contaminant concentrations than the soil being brought in from the disposal site.

The Similar Soils Provision Guidance recognizes several approaches to address the “significantly lower” evaluation criteria required by the MCP. These approaches include the following:

• Assume the soils at the receiving site are naturally occurring background concentrations. The most practical way of evaluating this is to compare concentrations in the managed soil with the MassDEP’s May 2002 Background Levels of Polycyclic Aromatic Hydrocarbons and Metals in Soil guidance.
• Sample soils at the receiving site.  The sampling plan would need to include a sufficient number of discrete soil samples to understand the concentrations and distribution of oil and/or hazardous materials throughout the receiving site. This data can then be used in a “rule of thumb” comparison which is outlined in the Similar Soils Provision Guidance document to simplify the evaluation.
• Provide technical justification for an alternative approach. The MassDEP recognizes that adequate analytical and non-analytical information may be available for both the managed soil and the receiving site whereby it sufficient to conclude that the not “significantly lower” criteria is met.

This may be potentially significant guidance.  A lot of soil, especially from urban redevelopment projects, with contaminant concentrations less than the Reportable Concentrations is reused as cover material in landfills when it could be reused at other locations.  The past lack of clear guidance on how to interpret the “significantly lower” criterion have made soil generators choose landfill reuse as a more conservative and safe measure. This issuance of the Similar Soils Provision Guidance may allow this type of soil to be more readily reused at other locations.  Time will tell how this gets put into practice.

The MassDEP cautions that the Similar Soils Provision Guidance is not applicable to the transport of soil from locations other than disposal sites regulated under the MCP or to the management of soil considered Remediation Waste under the MCP.

If you need more information about how the Similar Soils Provision Guidance might help you, please contact Omni Environmental Group’s Licensed Site Professional (LSP) at 978-256-6766 or solutions@www.omnieg.com.

“An LSP’s Opinion” is an occasional feature here in the Omni Environmental Group blog where we talk about the Massachusetts Contingency Plan along with the roles and responsibilities of Licensed Site Professionals.