The Department must be notified of a release or threat of a release as soon as possible but not more than two hours after obtaining knowledge when the release or threat of a release to the environment is indicated by:

• the measurement of one or more hazardous materials in soil or groundwater in an amount equal to or greater than the applicable Reportable Concentration;
• the measurement of oil and/or waste oil in soil in an amount equal to or greater than the applicable Reportable Concentration where the total contiguous volume of the oil and/or waste oil contaminated soil is equal to or greater than two cubic yards;
• the measurement of oil in groundwater in an amount equal to or greater than the applicable Reportable Concentration described in 310 CMR 40.0360 through 40.0369 and listed at 40.01600; or
• the presence of a subsurface Non-Aqueous Phase Liquid (NAPL) having a measured thickness equal to or greater than 1/8 inch and less than 1/2 inch.

A Release Notification Form is used to provide written notification of a release or threat of release to the Department on a form established by the Department for such purposes and provides information such as the location and address where the release or threat of release occurred, the time and date when the release or threat of release occurred, and the names and amounts of oil and/or hazardous material released or threatened to be released.