“Monthly” means once every calendar month, with at least one test or inspection, as applicable, occurring not sooner than 15 days after and not later than 45 days after:

1. (a) The date in the prior month on which the corresponding test or inspection occurred, if only one test or inspection, as applicable, occurred in the prior month; or
2. (b) The date in the prior month on which any corresponding test or inspection occurred, if an owner or AST operator performed the test or inspection more frequently than once in the prior calendar month.

Source. (See Revision Note at chapter heading for Env-Or 300) #10487, eff 2-7-14; ss by #14094, eff 10-4-24 (formerly Env-Or 302.26)