Waste Site Cleanup at MassDEP

The Waste Site Cleanup program at MassDEP is responsible for ensuring timely and effective responses to over 1,500 environmental emergencies (e.g. oil spills, chemical fires) per year, as well as timely assessment and cleanup of the more than 44,000 confirmed and suspected hazardous waste sites across Massachusetts by the private parties responsible for them.

Table of Contents

Encouraging Cleanup

Key Features

  • Reliance on Licensed Site Professionals (LSPs), experts in assessment and cleanup who are licensed by the Commonwealth and can be hired by the private sector to manage/oversee cleanups, allowing assessments and cleanups to proceed at most sites without delays due to the need to get MassDEP approvals.
  • Opportunities and incentives for cleaning up small problems quickly, and avoiding more structured and expensive response action requirements. In some cases, "Limited Removal Actions" performed before a notification deadline can keep a site out of the system entirely. "Release Abatement Measures" can be conducted to reduce risks, limit the spread of contamination at sites that have been reported to MassDEP, and in some cases remove the need for additional response actions.
  • A level of MassDEP oversight of response actions that fits the nature of the problem. For example, MassDEP oversees cleanup of spills and situations presenting "imminent hazards" when appropriate.
  • MassDEP audits of response actions at sites to ensure that private sector cleanups are done properly.

A Streamlined Process

MassDEP has streamlined requirements for response actions, providing greater certainty and a more flexible process:

  • Clear notification thresholds for historical contamination that screen out problems that are not likely to cause a significant risk to public health and the environment;
  • No upfront MassDEP approvals for most sites; and one for many others, reducing processing time and costs for the private sector;
  • Performance standards that allow the level of investigation to be set by the nature of the problem;
  • Numerical standards for deciding "how clean is clean enough" for 107 of the most common contaminants, and the ability to factor in site-specific information where appropriate;
  • Ability to tailor cleanup decisions to fit the current and planned use of a property and to use "Activity and Use Limitations" (deed restrictions and deed notices) that lock in these uses and to provide critical information to future property owners about the cleanup; and
  • Providing clear endpoints to the process ("Permanent Solutions”, “Permanent Solutions with Conditions” and “Temporary Solutions") so that lenders, future owners and tenants (etc.) can find out what cleanup has been done at a site – with the documentation available on-line upon submittal to DEP.

Incentives for Cleanup

Other incentives for private parties to undertake response actions were also included in the amendments to M.G.L. c. 21E:

  • Clarified liability of secured lenders and fiduciaries to ensure that, as long as they meet certain requirements, they will not be held responsible for cleanup costs. These clarifications should encourage lending and trust management of contaminated properties.
  • Clarified rights of liable parties and others who respond to releases to make it easier for other liability parties to contribute to response actions.
  • A dispute resolution mechanism has been provided that private parties must use to obtain participation from other possibly liable parties.
  • Private parties conducting response actions have the right to gain access to contaminated property for assessment and cleanup work.

The Regulatory Process

56,302   Releases Reported since 1984

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 criterion 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 follow-up. 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 types of actions.


  • 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.


  • 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 choose 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.


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.


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!

Key Actions   for The Regulatory Process

Additional Resources   for The Regulatory Process

The Privatized Program

408   Active Licensed Site Professionals (LSPs) in 2023

Since October 1, 1993, the cleanup of contaminated sites in Massachusetts has been largely "privatized". This approach was adopted to enable (and compel) the private sector to take more responsibility for remedial obligations, and to free up agency staff to address the most pressing public health and environmental threats facing the Commonwealth. Under this system, most sites are investigated and cleaned up with little or no up-front MassDEP involvement.

The idea behind this approach is to use limited government resources in a manner which achieves the greatest environmental benefit. Three important elements constitute the underpinnings of this program:

Comprehensive Regulations

Detailed procedures and requirements on how to clean up sites in the privatized system are contained in the Massachusetts Contingency Plan (MCP). These rules specify the process that should be followed to evaluate and document site conditions and needed remedial activities. Because MassDEP is not overseeing response actions at most sites, a number of documentation and submittal "check in" points have been stipulated, so that all will be aware of the progress that is being made (or not being made) at every site. There are also extensive requirements on when and how to notify local officials and the public on conditions and actions of particular concern, including opportunities and mechanisms for the public to become more involved in any site by requesting a Public Involvement Plan. It is important to note, however, that while the regulations specify how clean a site needs to be for a particular use, they do not specify how to demonstrate or achieve this level of cleanliness - this is something that must be decided on a case-by-case basis by Licensed Site Professionals, in conformance with the performance standards specified in the MCP, and subject to possible future audit by MassDEP.

Licensed Site Professionals (LSP)s

Just as most building codes require the use of a Registered Professional Engineer to interpret, apply, and document compliance with structural design standards, the Massachusetts Contingency Plan requires the use of Licensed Site Professionals (LSPs) to evaluate and oversee the remediation of contaminated sites. Similar to Professional Engineers, LSPs are licensed and policed by a state board (independent from MassDEP). To qualify and practice as an LSP, a person must possess a minimum number of years experience and/or specialized training and education in environmental assessment and/or cleanup, and must abide by specified standards of practice. The required use of LSPs attempts to ensure a minimum level of competence, ethical conduct, and professional accountability in a privatized process. A list of LSPs and other relevant information can be obtained from the Board of Registration of Hazardous Waste Cleanup Professionals.

MassDEP Audit and Oversight Programs

While the agency has delegated considerable authority to the private sector to oversee the cleanup of contaminated sites, it has by no means removed itself from the process, nor absolved itself from the responsibility of ensuring that all contaminated sites in Massachusetts are adequately assessed and cleaned up. To meet its obligations in this regard, MassDEP performs three important oversight functions:

  • Oversight of Immediate Response Actions - BWSC staff perform limited, short-term oversight of emergency and/or time-critical pollution situations. Once the site has been sufficiently stabilized, further assessment and cleanup actions may then be delegated solely to a Licensed Site Professional.
  • Audits- To "keep people honest", the agency performs both random and targeted inspections and audits on assessment and cleanup activities at sites being addressed by the private sector without direct MassDEP oversight. The nature of these audits range from screening and/or focused reviews, to formal, detailed, and comprehensive evaluations of conducted activities.
  • Enforcement - In cases where responsible parties have failed to meet their assessment and cleanup obligations, MassDEP undertakes a variety of enforcement actions to penalize past performance, and ensure adequate responses in the future. These actions range from the issuance of a Notice of Non Compliance to the issuance of orders and/or penalties, and for particularly egregious cases, seeking imprisonment and criminal penalties.

Key Actions   for The Privatized Program

Additional Resources   for The Privatized Program

Cleanup Process Diagram

> 42,000   Sites Closed Since 1993

This diagram illustrates the path a site may take through notification, assessment, cleanup and closure. Some actions - like the identification of an Imminent Hazard - may occur at any point in the process. A site may be closed when there is sufficient evidence to document a condition of No Significant Risk has been achieved and other requirements for closure are met.

flow chart of the MCP site cleanup process

(click on image to enlarge)

Additional Resources   for Cleanup Process Diagram

Image credits:  The Graves Light Station from MassDCR's Middlesex Fells Reservation (Paul Locke)

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