The first significant changes to the Massachusetts Contingency Plan in more than eight years were published today and reflect a three-year effort by the Massachusetts Department of Environmental Protection to streamline requirements to allow the agency to “do more with less” and to update the regulations to reflect developments in science and technology.  Although the revisions do not alter the fundamental way in which the MCP governs site cleanup in Massachusetts, the changes will affect every site and potentially every decision made by Licensed Site Professionals on assessment and remediation.  The new regulations, available in unofficial form here, are effective June 20, 2014, except some provisions described below become effective immediately.   

New Names, Procedures, and Closure Requirements

Tier Classification and Tier I Permit.  The new MCP streamlines the old tier classification process by eliminating the Numerical Ranking System and replacing it with a limited set of criteria.  The MCP has always ranked sites based on certain criteria, with the goal of providing additional oversight to sites that pose the most risk to sensitive receptors.  Under the Numerical Ranking System, LSPs would complete a questionnaire for each site, which resulted in a number used to determine if the site should be classified as Tier I (resulting in greater oversight by MassDEP and the need for a permit) or Tier II (resulting in less oversight).  Now, sites that meet one or more of these new criteria are Tier I (with no permit requirement anymore):

• concentrations of oil or hazardous material in groundwater within a certain distance from an actual or potential drinking water supply exceed the reportable concentration for drinking water;

• an imminent hazard is present;

• remedial action is required under an Immediate Response Action (IRA); or

• response actions are required as part of an IRA to eliminate or mitigate a Critical Exposure Pathway.

All other sites are Tier II, except for those that are considered to be in default from the regulatory timelines, which are Tier ID.  A site may be reclassified at a later time from Tier I to Tier II, or from Tier II to Tier I.

These regulations will become effective today and include a transition provision to address existing sites.  Existing Tier IA, IB, and IC sites will become Tier I sites.  Existing Tier ID and II sites will remain unchanged.  Existing sites that were already classified as Tier II but have conditions that meet the inclusionary criteria for Tier I do not need to be re-classified as Tier I if the potentially responsible party had knowledge of and was conducting response actions to address that condition prior to today.

Fees.  MassDEP assesses fees for each site at which response actions are being conducted under the MCP.  These fees are not in the MCP, but are found in 310 CMR 4.00.  MassDEP has proposed to change the fee regulations to reflect the streamlining in the Tier Classification provisions.  Most sites will not see a significant change in fees, except sites previously classified as Tier IA will see substantially reduced fees.  

More Time for Completing Work at Some Sites.  The new MCP allows an additional year to complete the comprehensive site assessment, acknowledging the reality that more complicated sites often take longer than the two years previously allowed under the MCP to determine the nature and extent of the contamination.  However, there is no change in the total time (five years after Tier Classification) allowed to complete a cleanup and reach a Permanent or Temporary Solution. 

Numeric Standards.  The reportable concentrations and cleanup standards for many contaminants have changed, in most cases becoming more stringent, including for 1,4 dioxane, lead, PCBs, and trichloroethylene. 

Source Control.  MassDEP has reworked the requirements for showing that a source has been controlled so that a site may be closed.  The new MCP requires LSPs to address (1) “all Sources of OHM Contamination” and (2) the potential for migration. 

“Source(s) of OHM Contamination” refers to the original structure or thing from which oil or hazardous material (OHM) was released and contaminated media in that original location from which migration can occur.  The downgradient leading edge of a plume of dissolved OHM is not considered a source.  In order to achieve a Permanent Solution, such sources must be eliminated if feasible; if not, they must be controlled. 

 “Migration Control” requires that dissolved plumes of OHM in groundwater or in vapor phase must be stable or contracting (i.e., not getting larger) in order to achieve a Permanent Solution. 

Permanent Solutions and Temporary Solutions.  The new regulations jettison the phrase “Response Action Outcome Statement” or RAO and replace the various classes of RAOs with phrases that are more understandable to the public:  Temporary Solution, Permanent Solution without Conditions, and Permanent Solution with Conditions.  This change is intended to make clear to the public the type of closure that has been achieved.    

A Permanent Solution with Conditions refers to site closures with one of two types of condition:  (1) a deed restriction known as a Notice of Activity and Use Limitation (AUL); or (2) a new type of closure, where conditions are imposed but no AUL is required.  This second type of condition can be used in the following situations:

• elevated contaminants remain under roadways;

• elevated contaminants pose a significant risk for residential use only if residential gardening for food occurs without following best management practices;

• Historic Fill, as defined, remains in place; and

• the potential for future buildings in areas that are potentially susceptible to indoor air concerns based on site data.

Sites with Nonaqueous Phase Liquid (NAPL)

For the first time, the new MCP allows sites with light nonaqueous phase liquid (LNAPL) in any well above ½-inch thick to achieve closure.  MassDEP developed a new vocabulary to define when and how such sites can be closed: a Permanent Solution is not achieved for any NAPL site unless response actions ensure that “Non-Stable NAPL” is not present under current site conditions and for the foreseeable future and all NAPL with “Micro-Scale Mobility” is removed if and to the extent feasible based upon Conceptual Site Model principles.  In other words, the MCP goal is to remove all NAPL when feasible, but if some NAPL with Micro-Scale Mobility remains, an AUL must be implemented. 

Non-Stable NAPL is  “NAPL that is expanding laterally or vertically by:  (a) migrating along or within a preferred flow path; (b) discharging or periodically discharging to a building, utility drinking water supply well, or surface water body; or (c) spreading as a bulk fluid through or from subsurface strata.”  Non-Stable NAPL is sometimes referred to as having macro-scale mobility.  NAPL with Micro-Scale Mobility is “a NAPL with a footprint that is not expanding, but which is visibly present in the subsurface in sufficient quantities to migrate or potentially migrate as a separate phase over a short distance and visibly impact an excavation, boring or monitoring well.” Stable NAPL is any NAPL that is not Non-Stable NAPL. 

MassDEP has indicated that it will be providing guidance on how to determine whether NAPL is stable or not, and that this determination will be based on a multiple lines of evidence approach.

Vapor Intrusion

The new MCP builds on MassDEP’s 2011 Interim Final Vapor Intrusion Guidance and discussions with stakeholders that began in 2009 to better address vapor intrusion in occupied commercial and residential buildings by addressing issues that could not be handled by guidance alone. 

Notification.  The final rules expand the conditions that trigger notice to MassDEP associated with the potential for vapor intrusion.  Notification within 72 hours of the potentially responsible party (PRP) gaining knowledge is required for any release that has resulted or is likely to result in indoor air contamination at a school, day care, child care center, or occupied residence including the following situations:

• soil or soil gas contamination by VOCs has been identified within 6 feet horizontally and 10 feet vertically from the structure at concentrations likely to discharge vapors into the structure;

• VOCs have been identified in groundwater at concentrations that exceed the GW-2 standard within 30 feet of the structure and the average annual depth to groundwater is 15 feet or less; and

• evidence has been identified of vapor migration along preferential pathways at a location likely to result in the discharge of vapors within the structure.

Assessment.  There has been confusion over when modeling of indoor air concentrations from soil gas is allowed for purposes of determining whether the indoor air condition poses a significant risk.   Consistent with the 2011 Interim Final Vapor Intrusion Guidance, the revised rules state that risk evaluations should be based on the measured indoor air concentration.  Modeling remains available to rule out the existence of a vapor intrusion pathway, and when necessary to distinguish site-related contamination from commercial or industrial operations inside the building.  However, it may not be used to evaluate indoor air for future buildings.

Closure with Active Systems.  The new MCP allows sites with an active system for addressing indoor air contamination to obtain a permanent solution with an AUL with required operation and maintenance of the system.  These closures are called Permanent Solutions with Conditions.  MassDEP had considered requiring a permit for such systems, but has decided that the AUL is sufficient to ensure compliance.

There are typically two methods that can be employed to significantly reduce indoor air contamination.  First, soil containing VOCs can be excavated and removed, especially where this material is not located under a building.  Second, the path by which volatiles move from the soil through the building slab and into the indoor air can be blocked or eliminated.  This is typically done by installing a vapor barrier and sub-slab depressurization system.  When these systems have blowers to maintain the appropriate pressure, they are active systems.  The revised rules create a new phrase for systems that prevent vapor intrusion: Exposure Pathway Mitigation Measures.  These can be “active” systems, meaning they rely on continual or periodic use of a mechanical or electro-mechanical device, or “passive” systems, which do not rely on such devices.

The AUL for an active system must include certain specific provisions, including the use of remote monitoring technology that will immediately notify the owner and operator of a building and MassDEP of a failure of such system such as loss of power, mechanical failure or significant disruption of the effectiveness of the system.  If the failure is not corrected within 30 days, the PRP must notify MassDEP and non-transient occupants of the failure.  An annual certification is also required.

Future Buildings.  Previously, the MCP did not require that LSPs address vapor intrusion that may occur when a new building is built unless a new building is being planned or constructed at the time of closure.  Instead, when a new building is later built on a site that had been closed, an LSP must be hired to evaluate the existing closure.  MassDEP has expressed concern that in some cases the risk posed by vapor intrusion is not identified and therefore these evaluations may not be occurring.  The new MCP requires that the Permanent Solution be “with Conditions.”  The Condition may be an AUL, but does not have to be.  The AUL or the condition will provide notice to any future owner that the site should be evaluated for vapor intrusion before any building is constructed.

Historic Fill

The new MCP balances the recognition that in some cases clean up of Historic Fill should not be required and yet may pose a risk to current or future occupants of the property.  The new MCP identifies Historic Fill as a type of “Anthropogenic Background” that does not require remediation.  Closure is achieved with a Permanent Solution with Conditions to ensure future landowners are aware of the potential risks associated with Historic Fill.

The MCP has long recognized that concentrations of contaminants that are consistent with background do not require remediation.  Background was defined to include naturally occurring contamination that was ubiquitous and consistently present in the vicinity of the site, as well as contaminants that result from certain specific common processes such as petroleum residues from motor vehicles.  Historic fill, which is common in urban settings, was generally not considered background and required significant assessment and in some cases remediation to achieve closure.

What qualifies as “Historic Fill” is very fact-specific.  Historic Fill is defined as:

Fill Material that based on the weight of the evidence and consistent with the Conceptual Site Model:

• was emplaced before January 1, 1983;

• may contain, but is not primarily composed of, construction and demolition debris, reworked soils, dredge spoils, coal ash, wood ash, or other solid waste material;

• was contaminated with metals, hydrocarbons, and/or polycyclic aromatic hydrocarbons prior to emplacement, at concentrations consistent with the pervasive use and release of such materials prior to 1983;

• does not contain oil or hazardous materials originating from operation or activities at the location of emplacement;

• is not and does not contain a generated hazardous waste, other than Oil or Waste Oil;

• does not contain chemical production waste, manufacturing waste, or waste from processing of metal or mineral ores, residues, slags or tailings; and

• does not contain waste material disposed in a municipal solid waste dump, burning dump, landfill, waste lagoon or other waste disposal location.

We believe that application of this concept at sites will pose significant challenges because evaluation of these criteria requires detailed site histories of the type not available at most sites.   We anticipate that MassDEP will issue guidance on how to approach these criteria when limited information is available. 

Deed Restrictions

MassDEP has made simplifying changes to the AUL requirements, including: 

• The AUL Opinion is no longer required.  Instead, MassDEP will rely on the other MCP submittals for the LSP’s opinion that an AUL is appropriate.  Because the AUL Opinion will no longer be recorded with the AUL, a brief discussion of site conditions and why an AUL is being implemented will need to be provided with the AUL.

• Clarification of what types of documents can be used to show that the person signing the AUL has authority to do so on behalf of a company, partnership or other entity, as appropriate.

The MCP has long required that AULs be referenced in the deed if the property is later sold.  MassDEP has indicated that failure to do so is a common violation of the MCP.  MassDEP has changed the AUL form to highlight this requirement.  In addition, the revised regulations require that documentation be submitted to MassDEP after a property transaction in order to confirm that this requirement has been met.