(1) The provisions of this rule apply only to proposed non-public alternate water supply systems in subdivisions. Public water supply systems must meet the requirements of Title 75, chapter 6, MCA, and rules promulgated thereunder.

(2) A water source other than a well may be developed only if the applicant:

(a) shows that it is not economically feasible to develop a well or that ground water quality, quantity, or dependability is unacceptable; and

(b) complies with the other requirements set out in this rule.

(3) The applicant shall provide evidence to the reviewing authority that the alternate water source is sufficient in terms of quality, quantity, and dependability.

(4) Springs, when developed as an alternate water system, must be constructed in accordance with a plan approved by the reviewing authority and in accordance with Department Circular DEQ-11. Springs must also meet the requirements for wells regarding quality, quantity and dependability in ARM 17.36.331 and 17.36.332.

(5) The reviewing authority may require that the applicant collect information regarding quality, quantity, and dependability of the water supply at specified times of the year.

(a) The reviewing authority may require water quality sampling to test for direct influence by surface water. Such sampling may include:

(i) testing for pH, temperature, conductivity, and turbidity;

(ii) testing for parameters with human health standards listed in Department Circular DEQ-7;

(iii) testing for organisms that indicate direct influence by surface waters according to Department Circular PWS-5; and

(iv) seasonal bacteriological testing.

(b) The reviewing authority may determine the adequacy of water quantity and water dependability based upon flows during the seasonal low-flow period.

(6) Cisterns may be utilized only if:

(a) a potable water source is available for hauling within a reasonable distance from the cistern and:

(i) a licensed water hauler supplies water for the cistern and provides a letter verifying that the subdivision will be served by the hauler’s business; or

(ii) the water supply is from a public water system and the owner of the public water system certifies that water is available from the public water system to serve the applicant’s cistern;

(b) all water is hauled and disinfected in accordance with ARM Title 17, chapter 38, subchapter 5, or a reviewing authority-approved plan; and

(c) the cistern is constructed and installed in accordance with a plan approved by the reviewing authority and in accordance with department Circular DEQ-17.