ARSD 74:04:01:06. Samples shall be tested by a certified laboratory -- Frequency

Representative samples of fluoridated water shall be collected from the distribution system and submitted for testing to a laboratory certified by the department for fluoride testing. Sample results from the laboratory shall be reported to the department monthly either as a hardcopy report or electronic means acceptable by the department. Samples shall be collected in accordance with the following schedule: (1) Population over 10,000: one sample per week; (2) Population of 3,000 to 10,000: two samples per month; and (3) Population less than 3,000: one sample each month.