(1) Where fluoridation is practiced, laboratory analysis must be made at least once daily of the water after fluoridation to assure an average fluoride content of not over 1.5 ppm in the finished water, using a control range from 0.9 ppm lower limits to 1.5 ppm upper limit.

(2) Proper records of the analyses must be kept on file and a copy forwarded to the department monthly. One sample of treated water must be submitted monthly to the department for analysis.