The Massachusetts Contingency Plan (the MCP, 310 CMR 40.0000) lays out a detailed process on when and how contaminated sites must be assessed and cleaned up:


  • Section 40.0300 of the MCP contains explicit criteria on the types and magnitude of releases that must be reported to MassDEP; who is required to make those notification; and the timeframes and procedures for those notifications.
  • Reportable Quantities (RQs) have been established for sudden spills of oil and hazardous materials; Reportable Concentrations (RCs) have been established for soil and groundwater contaminants. RQs and RCs are provided for each of the (several thousand) oils and hazardous materials covered by The Massachusetts Oil and Hazardous Material List (MOHML) .  The most commonly triggered notification criteria is the sudden spill of more than 10 gallons of a petroleum product. There are also additional notification triggers to address other emergency and time-critical environmental conditions, such as the presence of explosive vapors, oil sheens on surface waters, and fish kills.
  • Three types of notifications thresholds have been established: those spills/conditions requiring notification within 2 hours of obtaining knowledge; site conditions requiring notification within 72 hours of obtaining knowledge; and site conditions requiring notification within 120 days of obtaining knowledge. Notifications required within 2 or 72 hours are provided by telephone, with a written followup. Notifications required within 120 days of obtaining knowledge of a reporting trigger are provided in writing. In all cases, the written notification must be submitted using a Release Notification Form (RNF).


  • Once a release or threatened release of oil or hazardous material is reported to MassDEP, a regulatory clock starts, and Preliminary Response Actions must occur. Within 1 year, the site must either be cleaned up, or it must be classified as either Tier I or Tier II, and undergo a comprehensive assessment and cleanup program.
  • The first year following notification of a release is sometimes referred to as the Front End of the process. It is during this time that Risk Reduction measures are taken to address serious and localized problems, in an attempt to stabilize site conditions, and completely remediate smaller sites, respectively. A Phase I assessment is also done, if necessary, and for larger sites, a Phase II and Phase III may also be conducted, if it is possible to do so in this limited time period. The whole idea is to reduce risk at serious sites, and close out smaller problems with as little process and within as little time as possible.
  • The MCP mandates risk reduction measures in some cases, and encourages their use elsewhere. An Immediate Response Action (IRA) is a mandatory risk reduction measure, and it must be taken at all sites which have spill or site conditions requiring notification to MassDEP within 2 or 72 hours. A Release Abatement Measure (RAM) is a voluntary remedial measure taken to totally clean up small problems, or reduce the magnitude of larger problems.
  • Risk Reduction measures require submittal of a plan before it is implemented and certain notices to local officials. There are also opportunities for the public to become more involved in these type of actions, as further detailed in Public Involvement .


  • If a site is not closed out within 1 year of notification,a Tier Classification Submittal must be filed. 
  • Sites are classified as Tier I or Tier II, depending upon information obtained from a Phase I Initial Site Investigation. 
  • A series of notifications to local officials and Legal Notices are required for Tier Classified sites. The public also has an opportunity to become more involved in sites that have been Tier Classified by filing a petition to designate a site a Public Involvement Plan (PIP) site. Details in this regard are provided at Public Involvement .


  • The nature and extent of contamination must be sufficiently determined at each site, and a risk assessment must be undertaken to determine whether a condition of No Significant Risk exists, needs to be achieved, or has been achieved. The MCP provides for a tiered risk assessment approach, similar to the Risk-Based Corrective Actions (RBCA) process advocated by the American Society for Testing and Materials (ASTM), a national standards-setting organization:

    • Method 1 - allows for the comparison of concentrations of site contaminants to generic risk-based cleanup standards that have been developed by MassDEP for 111 common environmental contaminants;
    • Method 2 - allows for the limited modification of Method 1 standards, based upon site-specific fate and transport considerations (i.e., how a contaminant acts and migrates in the environment), as well as the development of standards for chemicals without Method 1 standards; or
    • Method 3 - allows for a completely site-specific risk assessment. The promulgated risk management standards for the protection of human health are: for non-cancer (threshold) effects, a cumulative Hazard Index equal to or less than 1.0; for cancer (non-threshold) effects, a cumulative Excess Lifetime Cancer Risk (ELCR) level equal to or less than 1 in 100,000.

    With a few exceptions, parties conducting an assessment are free to chose any of these risk assessment methods.


  • Once a condition of No Significant Risk has been demonstrated or achieved, all releases and threats of release that require notification to MassDEP must be closed out by filing a Permanent or Temporary Solution Statement. The MCP allows for the achievement of different levels of cleanliness, depending upon existing and future land uses. Three types of Solution have been structured: those where a cleanup was conducted; those where a cleanup was deemed unnecessary; and those where a Temporary Solution was achieved because a Permanent Solution is not feasible. Further refinements have been established:

  • A Remedy Operation Status (ROS) may be achieved at sites where contamination has been controlled, but where active cleaning measures (e.g., pumping and treating groundwater) will be required for many years.
  • A Permanent Solution is still required to be achieved at sites filing a Temporary Solution Statement; whenever it becomes feasible to do so.
  • In all cases, site cleanups must attempt to remove contamination to levels that achieve or approach a "background" condition, to the extent technologically and economically feasible.
  • Site closure may be achieved at any point in the assessment process where the site has been sufficiently characterized, and all applicable MCP performance standards have been met. It is even permissible to file a Release Notification Form concurrent with a Permanent or Temporary Solution Statement, to simultaneously report and close-out a site.
  • In cases where cleanup was not achieved to the most protective use (i.e., a "residential" standard), a Notice of Activity and Use Limitation (AUL) must be attached to the deed of the contaminated property(ies) to document and provide notice of residual contamination, to minimize the possibility of future exposures to these contaminants.


If contamination that originated from a neighboring or nearby property migrates onto your (downgradient) property, you may be able to file for a Downgradient Property Status under the provisions of 310 CMR 40.0180. If you successfully obtain this status, you will not be required to cleanup this problem, at least for the time being, though you may be responsible to address any immediate concerns on your property (e.g., explosive vapors seeping into a building) if the party responsible for the contamination refuses to do so. For more details, read Overview of Downgradient Property Status .


Sites that are not actively overseen by MassDEP are subject to audit by the agency. In general, MassDEP may conduct a random audit of a Permanent or Temporary Solution Statement within 2 years of filing, or, where evidence exists indicating a potential problem with a site or filing, a targeted audit of a Permanent or Temporary Solution Statement within 5 years of filing. Unless and until a site/submittal is audited by the agency, the opinions/findings of the Licensed Site Professional are considered to be valid and complete. For more details, check the Audits Fact Sheet


At any point in the process, if the party responsible for the assessment and cleanup of a contaminated site is either unable or unwilling to take needed actions, MassDEP can draw money from the state "superfund" to hire contractors to start and/or finish the job. MassDEP also has state contractors on standby 24 hours a day to respond to emergency and spill conditions, if necessary. If state money is spent in this manner, the law allows the agency to recover up to 3 times its expenses from responsible parties - which provides a strong incentive for those parties that are financially capable to undertake the work themselves!

For full details, consult the Massachusetts Contingency Plan. For additional details on the "privatized" nature of the waste site cleanup program, see The Privatized Waste Site Cleanup Program .