The Massachusetts Contingency Plan was significantly revised effective October 1, 1993 when a new, privatized approach was adopted. Since then, DEP has worked with private-sector Licensed Site Professionals (LSPs) to assess and cleanup sites. This page asks and answers questions about the progress of cleanups since 1993.


  • How many releases have been reported to DEP?
    Since 1984, over 44,000 releases have been reported to the Department. Eighty-six percent of the notifications have been received since the privatized program took effect in 1993, averaging over 1,400 per year. (as of 6/30/13)

  • What accounts for the most notifications: sudden releases (spills) or historic contamination?
    Two-hour notifications, generally resulting from spills, account for over 40 percent of all the notifications received. The remaining amount is split between 72-Hour and 120-Day notifications, generally associated with leaking oil tanks and historic contamination, respectively.

  • Are the numbers of spills increasing each year?
    No. With the exception of 1999, when new federal rules governing underground storage tanks went into effect, and 2011, when there was a small increase, there has been a steady decline in release notifications. This trend is consistent with upgrades in underground storage tanks, better environmental management practices and a diminishing universe of undiscovered "historic" contamination.
  • Is the year-by-year data available to the public?
    Yes - by following this link

Response Action Outcomes (RAOs)

  • How many sites have been cleaned up (received an RAO) since 1993?
    31,944 sites, averaging over 1500 per year. (10/1/93-6/30/13)

  • How many sites have been cleaned up to background levels?
    9,948 sites (31%) have received a Class A-1 RAO, indicating that the site was cleaned up to background conditions. (10/1/93-6/30/13)

  • How many sites have achieved temporary solutions?
    3% (1065) of the sites cleaned up to date (6/30/13) have achieved temporary solutions, or Class C RAOs.

  • How many of the cleaned-up sites require deed notices or use restrictions as part of the remedy?
    7% (2,249) included an Activity and Use Limitation (AUL) as part of the final remedy. The vast majority of sites (28630, or 90%) are clean enough for unrestricted use. (The remaining 3% are Temporary Solutions.)

  • Is the year-by-year data available to the public?
    Yes - by following this link