Section NR 809.74 - Additional requirements for public water systems which chlorinate or fluoridate water(1) PUBLIC WATER SYSTEMS WHICH ADD FLUORIDE. (a) The water supplier for a community water system artificially fluoridating the water shall establish a monitoring program in order to maintain the fluoride concentration within the range of 0.6 to 0.8 milligrams per liter recommended by the dental health section of the department of health services for optimum dental benefits.(b) The monitoring program shall include: 1. Submission of the results of daily fluoride tests of samples from the distribution system.2. One sample per month taken from a representative location in the distribution system and submitted to the state laboratory of hygiene. The sample submitted to the state laboratory of hygiene shall be a portion of a split sample so that the operator can determine the fluoride concentration with the operator's equipment and compare it to the state laboratory results. The fluoride concentration obtained by the operator shall be noted on the data sheet prior to submission to the state laboratory.3. For public water systems with large distribution systems and multiple sources, more than one fluoride test per day may be necessary to assure proper feed rates. See s. NR 811.51(7) for testing equipment requirements.4. The department may approve exceptions to the daily fluoride test requirement if the water supplier is able to demonstrate that the optimum fluoride concentration in par. (a) can be maintained utilizing a reduced monitoring program. (2) CHLORINE. The water suppliers for all waterworks which chlorinate water shall test chlorine residuals at locations and intervals necessary to control the chlorination process. At groundwater supplies, the chlorine residual of a sample from a representative location in the distribution system shall be checked at least twice per week. Water suppliers for public water systems having surface water treatment plants or GWUDI systems shall determine the chlorine residual in the plant effluent continuously and in the distribution system at least daily in representative locations. Where water quality changes rapidly, residuals shall be tested at more frequent intervals as specified by the department and in those individual cases, continuous monitoring equipment may be required if the department determines it is necessary to protect public health. Chlorine residual testing is required when bacteriological samples are taken.Wis. Admin. Code Department of Natural Resources NR 809.74
CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.Amended by, CR 15-049: am. (1) Register March 2016 No. 723, eff.4/1/2016