NR 809.950(3)(c)5.5. Other violations and situations determined by the department to require a public notice under this subchapter, not listed in Appendix A.

NR 809.950(4)(a)(a) Public notice tiers. Public notice requirements are divided into 3 tiers, to take into account the seriousness of the violation or situation and of any potential adverse health effects that may be involved. The public notice requirements for each violation or situation listed in sub. (3) are determined by the tier to which it is assigned. The definition of each tier is provided in par. (b). Appendix A identifies the tier assignment for each specific violation or situation.

NR 809.950(4)(b)(b) Definition of public notice tiers.

NR 809.950(4)(b)1.1. Tier 1 public notice is required for NPDWR violations and situations with significant potential to have serious adverse effects on human health as a result of short-term exposure.

NR 809.950(4)(b)2.2. Tier 2 public notice is required for NPDWR violations and situations with potential to have serious adverse effects on human health.

NR 809.950(4)(b)3.3. Tier 3 public notice is required for NPDWR violations or situations not included in Tier 1 and Tier 2.

NR 809.950(5)(a)(a) Each water supplier for a public water system shall provide public notice to persons served by the public water system, in accordance with this subchapter. All water suppliers for public water systems that sell or otherwise provide drinking water to consecutive systems are required to give public notice to the water supplier for the consecutive system. The water supplier for a consecutive system is responsible for providing public notice to the persons it serves.

NR 809.950(5)(b)(b) If a public water system has a violation in a portion of the distribution system that is physically or hydraulically isolated from other parts of the distribution system, the department may allow the water supplier to limit distribution of the public notice to only persons served by that portion of the public water system which is out of compliance. If the department grants permission for limiting distribution of the notice, permission shall be granted in writing.

NR 809.950(5)(c)(c) A copy of the notice shall also be sent to the department, in accordance with the requirements under s. NR 809.80 (5).

NR 809.951(1)(a)(a) Appendix A identifies the tier assignment for each specific violation or situation requiring a Tier 1 public notice.

NR 809.951(1)(b)(b) Violation categories and other situations requiring a Tier 1 public notice include all of the following:

NR 809.951(1)(b)2.2. Violation of the MCL for nitrate, nitrite, or total nitrate and nitrite, as defined in s. NR 809.11, or when the water supplier for the public water system fails to take a confirmation sample within 24 hours of the water supplier’s receipt of the first sample showing an exceedance of the nitrate or nitrite MCL, as specified in s. NR 809.115 (6) (b).

NR 809.951(1)(b)3.3. Exceedance of the nitrate MCL by non-community water systems, where permitted to exceed the MCL by the department under s. NR 809.11 (3), as required under s. NR 809.958.

NR 809.951(1)(b)4.4. Violation of the MRDL for chlorine dioxide, as defined in s. NR 809.561 (2), when one or more samples taken in the distribution system the day following an exceedance of the MRDL at the entrance of the distribution system exceed the MRDL, or when the water supplier for the public water system does not take the required samples in the distribution system, as specified in s. NR 809.566 (3) (b) 1.

NR 809.951(1)(b)5.5. Violation of the turbidity treatment technique MCL under s. NR 810.29 (1), where the department determines after consultation that a Tier 1 notice is required or where consultation does not take place within 24 hours after the public water system learns of the violation.

NR 809.951(1)(b)6.6. Violation of the surface water treatment rule (SWTR) or interim enhanced surface water treatment rule (IESWTR) treatment technique requirement resulting from a single exceedance of the maximum allowable turbidity limit as identified in Appendix A, if the department determines after consultation that a Tier 1 notice is required or if consultation does not take place within 24 hours after the water supplier for the public water supply learns of the violation.

NR 809.951(1)(b)7.7. Occurrence of a waterborne disease outbreak, as defined in s. NR 809.04 (90), or other waterborne emergency, such as a failure or significant interruption in key water treatment processes, a natural disaster that disrupts the water supply or distribution system, or a chemical spill or unexpected loading of possible pathogens into the source water that significantly increases the potential for drinking water contamination.

NR 809.951(1)(b)8.8. Other violations or situations with significant potential to have serious adverse effects on human health as a result of short-term exposure, as determined by the department either in its regulations or on a case-by-case basis.

NR 809.951(1)(b)9.9. Detection of E. coli, enterococci, or coliphage in source water samples as specified under s. NR 809.325 (2).

NR 809.951(2)(2) Timing of a tier 1 public notice and additional steps. Water suppliers public water systems shall do all of the following if Tier 1 public notice is required:

NR 809.951(2)(a)(a) Provide a public notice as soon as practical but no later than 24 hours after the water supplier learns of the violation.

NR 809.951(2)(b)(b) Initiate consultation with the department as soon as practical, but no later than 24 hours after the public water system learns of the violation or situation, to determine additional public notice requirements.