If, after public hearing it finds that any public water supply is or is likely to be contaminated, or if waters designated as Class A by 10 V.S.A. § 1253 are reclassified by order of the Secretary of Natural Resources, the Board of Health shall order the municipality or person using or supplying such public water supply to construct and install filtration and disinfection facilities to protect the public health or convert to a new source of public water supply. Any such order shall specify a reasonable time schedule for such construction or conversion and shall specify any interim measures necessary for the protection of the public health. (Added 1969, No. 252 (Adj. Sess.), § 23, eff. April 4, 1970; amended 2011, No. 138 (Adj. Sess.), § 27, eff. May 14, 2012.)