(1) Factors that may be used in establishing priority for selection of sampling sites include, but are not limited to:

(a) local cropping practices;

(b) agricultural chemical use patterns;

(c) soil characteristics;

(d) depth to water table;

(e) ground water usage:

(i) public or private drinking water supply;

(ii) non-potable use;

(f) existing water quality;

(g) previous detections of agricultural chemical residues in ground water;

(h) the potential for adverse impact of impaired or degraded ground water on human health or the environment:

(i) number of wells per unit area;

(ii) volume of ground water used for human consumption per unit area.

(i) impairment or degradation of irrigation water;

(j) agricultural chemical user activities which may lead to ground water impairment or degradation;

(k) suspected misuse of chemicals, violation of Title 80, chapter 15, MCA, or violation of a SMP.

(2) The department will consider seasonal changes in ground water recharge and flux and irrigation scheduling when determining appropriate times to sample water.

(3) The department will re-evaluate site prioritization based on new or updated information.