MassDEP Enforcement Discretion Directive for UST Tightness Testing

Sep 18, 2017

MassDEP is exercising enforcement discretion on the tightness testing standard in the Underground Storage Tank (UST) regulation that is scheduled to take effect on January 1, 2018.  310 CMR 80.32(1) establishes the standard for tightness tests performed on USTs and piping.  It states:

  1. Until January 1, 2018, tank and piping/line tightness testing shall be capable of detecting a release or leakage of 0.1 gallon per hour, accounting for the effects of thermal expansion or contraction of regulated substance, vapor pockets, tank deformation, evaporation, condensation, and the location of the water table.  The probability of detection shall be no less than 95 percent and the probability of a false alarm shall be no more than five percent.
  2. On and after January 1, 2018, tank and piping/line tightness testing shall be capable of detecting a release or leakage of 0.05 gallon per hour, accounting for the effects of thermal expansion or contraction of regulated substance, vapor pockets, tank deformation, evaporation, condensation, and the location of the water table.  The probability of detection shall be no less than 95 percent and the probability of a false alarm shall be no more than five percent.

MassDEP is not aware of any tank tightness testing company in the United States that has equipment certified to meet a 0.05 gallon per hour leak rate with a 95% probability of detection. Therefore, MassDEP will not enforce the standard at 310 CMR 80.32(1)(b) that is scheduled to take effect on January 1, 2018.

The standard at 310 CMR 80.32(1)(a) will stay in effect until further notice.

CommTank technician testing a UST in Newton Ma This document does not constitute “final agency action,” and is not “regulation” as that term is used in M.G.L. c.30A. It may not be relied upon to create rights, duties, obligations or defenses, implied or otherwise, enforceable by any party in any administrative proceeding with the Commonwealth. In addition, this enforcement discretion directive does not exempt any person from complying with the other requirements in 310 CMR 80.00 or any other applicable local, state or federal law, including but not limited to the State Fire Code at 527 CMR 1.00.