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 45,000 releases have been reported to the Department.

  • 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

Sites Cleaned Up

  • How many sites have been cleaned up since 1993?
    33,139 sites, averaging over 1500 per year. 

  • How many sites have been cleaned up to background levels?
    10,446 sites (32%) have received a Class A-1 RAO or a Permanent Solution with No Conditions, indicating that the site was cleaned up to background conditions.
  • How many sites have achieved temporary solutions?
    3% (1,127) of the sites cleaned up to date (6/30/14) have achieved Temporary Solutions (Class C RAOs prior to Spring 2014) .

  • How many of the cleaned-up sites require deed notices or use restrictions as part of the remedy?
    7% (2,344) included an Activity and Use Limitation (AUL) or other conditions as part of the final remedy. The vast majority of sites (29668, 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