NR 809.68(1)(b)3.3. The quarterly average of monthly samples taken during the previous quarter or the result of the quarterly sample.

NR 809.68(1)(c)(c) The department may choose to perform calculations and determine whether the MCL was exceeded or the public water system is eligible for reduced monitoring in lieu of having the water supplier report that information

NR 809.68(2)(2) Recordkeeping. The water supplier shall retain any s. NR 809.62 monitoring plans and monitoring results collected under s. NR 809.61 as required by s. NR 809.82.

NR 809.68 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; correction in (2) made under s. 13.92 (4) (b) 7., Stats., Register November 2010 No. 659; CR 15-049: am. (1) (a) 3., (2) Register March 2016 No. 723, eff. 4-1-16.

subch. IV of ch. NR 809Subchapter IV — Miscellaneous Chemical Monitoring Requirements, Raw Surface Water Standards, and Certified Laboratories

NR 809.70(1)(1) Secondary standards. Waters containing inorganic chemicals in quantities above the limits contained in this section are not hazardous to health but may be objectionable to an appreciable number of persons. The following secondary standards for inorganic chemicals are listed in Table AA:

NR 809.70(2)(2) Applicability of secondary standards. The secondary standards contained in this section apply to all public water systems.

NR 809.70(3)(3) Compliance with the secondary drinking water standard and public notification for fluoride. Water suppliers for community water systems that exceed the secondary maximum contaminant level for fluoride as determined by the last single sample taken in accordance with the requirement of s. NR 809.113, but do not exceed the maximum contaminant level for fluoride as specified in s. NR 809.11, shall provide the notice as specified in s. NR 809.957 to all billing units annually, all new billing units at the time service begins and annually to the department and the department of health services.

NR 809.70 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; corrections in (3) made under s. 13.92 (4) (b) 6. and 7., Stats., Register November 2010 No. 659; CR 15-049: am. (1) Table AA, (2) Register March 2016 No. 723, eff. 4-1-16.

NR 809.71(1)(1) Complaints on aesthetic water quality. If the department receives complaints regarding the aesthetic quality of the water, the water supplier may be required to implement a monitoring program to determine compliance with s. NR 809.70.

NR 809.71(2)(2) Department required remedial action. If it is determined by the department that physical or chemical substances or both in excess of those standards contained in s. NR 809.70 are objectionable to an appreciable number of persons and are detrimental to the public welfare, the department may, on its own motion, require remedial action by the water supplier to insure that the public receives the highest quality water practicably obtainable.

NR 809.71(3)(3) Laboratory requirements. The department may require that laboratory test results submitted to the department under this section be performed by a laboratory certified or registered under ch. NR 149.

NR 809.71 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 15-049: am. (1), (2) Register March 2016 No. 723, eff. 4-1-16.

NR 809.73(1)(1) Other chemical testing. If the department determines that the public health, safety or welfare requires testing for chemical or physical constituents in water which are not contained in this chapter, the department may order such testing as it deems necessary.

NR 809.73(1)(a)(a) The department shall provide public notice and an opportunity for public hearing within 90 days after any order under this subsection.

NR 809.73(1)(b)(b) Hearings under this subsection shall be class 1 hearings and shall be held in accordance with ch. 227, Stats.

NR 809.73(1)(c)(c) Such testing shall be done at a laboratory certified or registered by EPA or under ch. NR 149 as the department may require on a case-by-case basis.

NR 809.73(2)(2) Treatment control testing. Testing for other constituents shall be performed at public water systems as determined necessary by the department for design and control of treatment processes for contaminants which may affect public health or welfare. Such testing shall be done at a laboratory certified or registered by EPA or under ch. NR 149 as the department may require on a case-by-case basis.