(a) Department may authorize variances from a maximum contaminant level.--The department may authorize variances from a maximum contaminant level under conditions and in such manner as are deemed necessary and desirable; provided, however, that such variances shall be granted only upon finding that:

Notwithstanding the foregoing, variances may be granted for no longer than two years, subject to one or more renewals of no longer than two years each.

(b) Variances from treatment technique requirements.--The department may authorize variances from a treatment technique required under the drinking water standards if the public water system applying for the variance demonstrates to the satisfaction of the department that the treatment technique is not necessary to protect the health of persons because of the nature of the raw water sources of the system.

(c) Department may authorize exemptions.--The department may exempt any public water system from any requirement of an applicable drinking water standard upon finding that:

All exemptions granted with respect to a contaminant level or treatment technique prescribed by the Federal regulation shall expire no later than the dates prescribed in the Federal act.

(d) Public notice.--The department shall provide public notice of a request for a variance or exemption provided for in subsections (a), (b) and (c). This notice shall provide for at least a 30-day public comment period and a public hearing before a variance or exemption is granted.

(e) Board to adopt regulations governing variances and exemptions.--Before the department shall grant any variance or exemption, the board shall first adopt regulations governing the procedures and conditions under which variances or exemptions may be granted.