Release Tracking Number (RTN): 

The number assigned to every site /reportable release. This number is preceded by 1, 2, 3, or 4 depending on the region where the release/site is located (e.g., 3-0001234). Corresponding regions are:

Western Region

Central Region

Northeast Region

Southeast Region

Additional information about RTNs may be found here .

City/Town:

The city or town where the release of oil or hazardous material occurred. Boston and Barnstable are also broken down by neighborhood or village (e.g., Boston-Brighton, Barnstable-Hyannis)

Release Address:

The number and street that most accurately describe the site/release location.

Site Name/Location Aid:

Describes the site in terms of its location, use, or type ("Bob's Gas Station" or "Across from Building 1").

Reporting Category:

How quickly a release must be reported to DEP. The potential severity of a release dictates how soon it must be reported. Reporting categories are 2 hours, 72 hours, and 120 days.

Notification Date:

The date DEP uses to establish 21E deadlines. This date is usually the date when the site/release was reported to DEP. However, for some sites, especially those dating before 1993, the notification date may be later than the date DEP first learned about the site.

Compliance Status:

  • 21E sites compliance status definitions:
  • ADEQUATE REG (Adequately Regulated): A site/release where response actions are deemed adequately regulated under another DEP program or by another government agency.
  • DEPMOU (Memorandum of Understanding): A site/release where DEP has a Memorandum of Understanding or other written agreement with a responsible party.
  • DPS (Downgradient Property Status): A site where a DPS Submittal to DEP has stated that contamination on the property is coming from an upgradient property.
  • DPSTRM (Downgradient Property Status Terminated): A site where Downgradient Property Status has been terminated.
  • INVSUB (Invalid Submittal): An RAO Statement that was submitted for the site has been determined to be invalid by DEP.
  • RAO (Response Action Outcome): A site/release where a Permanent or Temporary Solution Statement  (formerly RAO Statement)  was submitted. This statement asserts that response actions were sufficient to achieve a level of no significant risk or at least ensure that all substantial hazards were eliminated.
    • PSNC - Permanent Solution with No Conditions
    • PSC - Permanent Solution with Conditions
    • TMPS - Temporary Solution
    • RAORCD RAO Statement Received (Retired June 20, 2014)
  • REMOPS (Remedy Operation Status): A site where a remedial system which relies upon Active Operation and Maintenance is being operated for the purpose of achieving a Permanent Solution.
  • ROSTRM: A site where Remedy Operation Status has been terminated.
  • RTN Closed: Future response actions addressing the release associated with this Release Tracking Number (RTN) will be conducted as part of the response actions planned for the site under another "primary" RTN.
  • SPECPR (Special Project): The site has Special Project status.
  • STMRET (Statement Retracted): An RAO Statement that had been submitted for the site has been retracted.
  • TCEXT: A Tier Classification Extension has been received.
  • TCLASS (Tier Classification): A site/release where a Tier Classification Submittal was received, but the classification type has not been confirmed by DEP.
  • TIER 1: Site has been classified as Tier 1
  • TIER 2: Site has been classified as Tier 2
  • TIER 1D: A site/release where the responsible party fails to provide a required submittal to DEP by a specified deadline. Formerly Default Tier 1B.
  • URAM: A Release Tracking Number has been assigned to a release where a Utility-abatement Measure is being or was performed.
  • UNCLASSIFIED: A release that has not reached its Tier Classification deadline (usually one year after it was reported), and where a Permanent or Temporary  
    Solution Statement, DPS Submittal, or Tier Classification Submittal has not been received by DEP.

Note: Sites are usually Tier Classified based on a variety of factors. These include the site's complexity, the type of contamination, and the potential for human or environmental exposure to the contamination. 

The following definitions apply to sites that were reported to DEP prior to October 1993 and which were regulated under an older version of the MCP:

  • DEPNDS: DEP Not a Disposal Site means that DEP has determined that these locations did not need to be reported and are not disposal sites.
  • DEPNFA: DEP No Further Action means that response actions were conducted and DEP determined that no further action was needed for the site.
  • LSPNFA: LSP No Further Action means that response actions were conducted and an LSP has determined that no further action was needed for the site.
  • PENNDS: Pending Not a Disposal Site means a document was submitted to DEP asserting that these locations did not need to be reported and are not disposal sites. These submittals are considered pending until DEP audits them.
  • PENNFA: Pending No Further Action means a document was submitted to DEP asserting that a site assessment had determined that no further action was required. These submittals are considered pending until DEP audits them.
  • WCSPRM: A Waiver Completion Statement has been submitted to DEP.

Compliance Status Date:

The date a release/site was listed as its current compliance status.

Phase: Indicates the release/site cleanup phase.

  • No Phase: Phase report not required or not submitted.
  • Phase I: Initial Site Investigation, including Tier Classification. In this phase, samples are collected and analyzed to determine the types, amounts, and location of contaminants.
  • Phase II: Comprehensive Site Assessment. During Phase II, the risks posed to public health, welfare, and the environment are determined.
  • Phase III: Identification, Evaluation, and Selection of Comprehensive Remedial Action Alternatives and the Remedial Action Plan. In Phase III, cleanup options are assessed and a cleanup plan is selected.
  • Phase IV: Implementation of the Selected Remedial Action Alternative and Remedy Implementation Plan. The cleanup plan is implemented in Phase IV.
  • Phase V: Operation, Maintenance, and/or Monitoring. During Phase V, long-term treatment processes are implemented and monitored to track cleanup progress.

RAO Type:

  • PSARCD: Permanent Solution with Conditions and AUL
  • RPSAREV Revised Permanent Solution with Conditions and AUL
  • PSCRCD Permanent Solution with Conditions and no AUL
  • PSCREV Revised Permanent Solution with Conditions and no AUL
  • PSNRCD Permanent Solution with No Conditions
  • PSNREV Revised Permanent Solution with No Conditions
  • TSFRCD Temporary Solution Permanent Solution Feasible
  • TSFREV Revised Temporary Solution Permanent Solution Feasible
  • TSNRCD Temporary Solution Permanent Solution Not Feasible
  • TSNREV Revised Temporary Solution Permanent Solution Not Feasible
  • RAORCD RAO Statement Received (Retired June 20, 2014)

Note: Activity and Use Limitations (AULs) are legal restrictions used in the context of the Massachusetts Contingency Plan to limit future exposure to contaminants remaining at a site.

RAO Classes below have been discontinued as part of 2014 Regulatory Changes

  • Class A RAO- Remedial work was completed and a level of "no significant risk" has been achieved.

A1: A permanent solution has been achieved. Contamination has been reduced to background or a threat of release has been eliminated.

A2: A permanent solution has been achieved. Contamination has not been reduced to background.

A3: A permanent solution has been achieved. Contamination has not been reduced to background and an Activity and use Limitation (AUL) has been implemented.

A4: A permanent solution has been achieved. Contamination has not been reduced to background and an Activity and use Limitation (AUL) has been implemented. Contamination is located at a depth of >15 feet but evaluation has determined that it is not feasible to reduce it.

  • Class B RAO- Site assessment indicates that "no significant risk" exists. No remedial work was necessary.

B1: Remedial actions have not been conducted because a level of No Significant Risk exists.

B2: Remedial actions have not been conducted because a level of No Significant Risk exists, but that level is contingent upon one or more Activity and use Limitations (AULs) that have been implemented.

B3: Remedial actions have not been conducted because a level of No Significant Risk exists, but that level is contingent upon one or more Activity and use Limitations (AULs) that have been implemented, and contamination is located at a depth of >15 feet but evaluation has determined that it is not feasible to reduce it.

  • Class C RAO- A temporary cleanup. Although the site does not present a "substantial hazard", it has not reached a level of no significant risk. The site must be evaluated every five years to determine whether a Class A or Class B RAO is possible. All sites are expected eventually to receive a Class A or B RAO.

The Numerical Ranking Scoresheet (NRS) and Tier 1 Permits have been discontinued as part of 2014 Regulatory changes.  Tier Classifications below are no longer used.  

  • TIER 1A: A site/release receiving a total NRS score equal to or greater than 550. These sites/releases require a permit and the person undertaking response actions must do so under direct DEP supervision.
  • TIER 1B: A site/release receiving an NRS score of less than 550 and equal to or greater than 450. These sites/releases also require a permit, but response actions may be performed under the supervision of a Licensed Site Professional (LSP) without prior DEP approval.
  • TIER 1C: A site/release receiving a total NRS score of less than 450 and equal to or greater than 350. A site/release receiving a total NRS score of less than 350, but which meets any of the Tier 1 Inclusionary Criteria specified in 310 CMR 40.0520(2)(a), is also classified a Tier 1C. These sites/releases also require a permit, but response actions may be performed under the supervision of an LSP without prior DEP approval.