310 CMR, § 6.01
Ambient Air means that portion of the atmosphere, external to buildings, to which the general public has access.
Department means the Department of Environmental Protection.
Equivalent Method means a method of sampling and analyzing the ambient air for an air pollutant that has been designated as an equivalent method in accordance with 40 CFR Part 53; it does not include a method for which an equivalent method designation has been canceled in accordance with 40 CFR Part 53.11 or 53.16.
Reference Method means a method of sampling and analyzing the ambient air for an air pollutant that is specified as a reference method in an appendix to 40 CFR Part 50, or a method that has been designated as a reference method in accordance with 40 CFR Part 53; it does not include a method for which a reference method designation has been cancelled in accordance with 40 CFR Part 53.11 or 53.16.
310 CMR, § 6.01