The Department must be notified of a release or threat of a release as soon as possible but not more than 72 hours after obtaining knowledge when the release or threat of a release meets one or more of the following sets of criteria:

• a release to the environment indicated by the presence of a subsurface Non-Aqueous Phase Liquid (NAPL) having a measured thickness equal to or greater than � inch;
• a release to the environment indicated by the presence of oil and/or hazardous material within ten feet of the exterior wall of an underground storage tank, as established by measurement of equal to or greater than 100 parts-per-million (ppm) by volume of total organic vapors "as benzene" and where such sample was obtained:
  • greater than two feet below the ground surface; and
  • as part of a closure assessment or in connection with the removal or closure of an underground storage tank;
• a release to the environment indicated by the measurement of oil and/or hazardous material in the groundwater at concentrations equal to or greater than a Category RCGW-1 Reportable Concentration within:
  • the Zone I of a public water supply well; or
  • 500 feet of a private water supply well; or
  • measurement within the groundwater of equal to or greater than five milligrams per liter of total volatile organic compounds at any point located within 30 feet of a school or occupied residential structure, where the groundwater table is less than 15 feet below the surface of the ground; or
  • a condition of Substantial Release Migration;
• a release from an underground storage tank where there is a substantial likelihood of a leak:
  • equal to or greater than 0.05 gallons per hour in a single walled tank or the inner wall of a double?walled tank; or
  • in the outer wall of a double?walled tank.

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.