(1) The phrase "minimum general sanitary standards" as used in this part 2 and section 25-1-109 (1)(h) means the minimum standards reasonably consistent with assuring adequate protection of the public health, and, in the case of minimum general sanitary standards as to the quality of water supplied to the public, the same shall be established by rule and regulation and shall be appropriate to promote and protect the public health from endangerment presented by carcinogenic, mutagenic, teratogenic, pathogenic, or toxic contaminants or substances. Such standards shall be based on the best available endangerment assessment evidence and the best available treatment technology or methodology. The word "standards" as used in this part 2 and section 25-1-109 (1)(h) means standards reasonably designed to promote and protect the public health.

(2) Minimum general sanitary standards for the quality of water supplied to the public shall be no more stringent than the drinking water standards promulgated pursuant to the federal "Safe Drinking Water Act", if such standards exist. If no standards have been promulgated pursuant to the federal "Safe Drinking Water Act" regarding the permissible concentration of any contaminant or any substance in drinking water, the department may recommend to the water quality control commission for promulgation minimum general sanitary standards regarding such contaminant or substance.

(3) (a) The department shall annually establish and revise a priority list of contaminants or substances for which standards may be considered and shall submit said list to the water quality control commission for review and approval.

(b) The priority list of contaminants or substances, together with the department's evaluation of the considerations listed in this paragraph (b), shall be submitted to the water quality control commission for review and approval. The priority list shall be prepared according to a ranking process that incorporates the following considerations:

(I) The actual presence of a contaminant or substance in a drinking water supply system or the relative imminence of threat of contamination of a drinking water supply source;

(II) The identifiability of a potential pathway or continued pathway of contamination;

(III) The availability of analytical techniques for measuring and identifying the contaminant or substance in a reasonable manner;

(IV) Sufficient available information concerning the contaminant or substance to allow an appropriate standard to be developed, including information on the health effects of the contaminant or substance as well as available treatment technology;

(V) The magnitude of potential health risks of the contaminant or substance at reasonably anticipated exposure levels, utilizing the same exposure considerations, criteria for health risk, and criteria for data availability which are used by the criteria and standards division of the office of drinking water, United States environmental protection agency, in establishing the federal drinking water priority list;

(VI) The fact that the contaminant or substance will be the subject of a national primary drinking water regulation in the near future;

(VII) An analysis of the environmental fate and transport mechanisms within relevant environmental media;

(VIII) Identification, characterization, and analysis of the populations and drinking water supplies at risk; and

(IX) The level of effort and scope of work that will be necessary to develop sufficient data for the purpose of supporting an appropriate standard.

(4) (a) Following the department's submission of recommended standards to the water quality control commission, the commission may promulgate standards for contaminants or substances that are not the subject of a standard set pursuant to the federal "Safe Drinking Water Act".

(b) In the promulgation of such standards, the water quality control commission shall find that the standards are necessary to protect public health and have a demonstrated medical, technological, and scientific basis and that:

(I) Based on credible medical and toxicological evidence that has been subjected to peer review, there exists a substantial risk to the public health;

(II) The analytical techniques for measuring and identifying the contaminant or substance are reasonably available;

(III) The adverse health effects posed by the contaminant or substance are known to a reasonable degree of scientific certainty; and

(IV) Compliance with such standard is feasible utilizing the best technology or methodology which is generally available.

(5) All acts, orders, and rules adopted by the state board of health under the authority of this part 2 prior to July 1, 2006, that were valid prior to said date and not otherwise subject to judicial review shall, to the extent that they are not inconsistent with said provisions, be deemed and held to be legal and valid in all respects, as though issued by the water quality control commission under the authority of this part 2. No provision of this part 2 shall be construed to validate any actions, orders, or rules that were not valid when adopted by the board of health prior to such date.