Wisconsin Administrative Code
Department of Natural Resources
NR 800 - Environmental Protection - Water Supply
Chapter NR 810 - Requirements for the operation and maintenance of public water systems
Subchapter II - Surface Water Treatment and Groundwater Under the Direct Influence of Surface Water Treatment Operations
Section NR 810.33 - Enhanced treatment requirements for Cryptosporidium

(a) Wholesale systems shall comply with the requirements of this section based on the population of the largest system in the combined distribution system.

(b) The requirements of this section for filtered systems apply to water systems required by s. NR 810.29 to provide filtration treatment, whether or not the system is currently operating a filtration system.

(c) The requirements of this section for unfiltered groundwater systems under the direct influence of surface water apply only to unfiltered systems that timely met and continue to meet the filtration avoidance criteria in s. NR 810.30.

(a) Water suppliers shall conduct an initial and a second round of source water monitoring for each plant that treats a surface water or GWUDI source. This monitoring may include sampling for Cryptosporidium, E. coli, and turbidity as described in s. NR 809.331, to determine what level, if any, of additional Cryptosporidium treatment they shall provide.

(b) Water suppliers for systems that plan to make a significant change to their disinfection practice shall develop disinfection profiles and calculate disinfection benchmarks, as described in s. NR 810.32.

(c) Water suppliers for filtered systems shall determine their Cryptosporidium treatment bin classification as described in s. NR 810.34 and provide additional treatment for Cryptosporidium, if required, as described in s. NR 810.35. All unfiltered GWUDI systems shall provide treatment for Cryptosporidium as described in s. NR 810.36. Filtered systems and unfiltered GWUDI systems shall implement Cryptosporidium treatment according to the schedule in s. NR 810.37.

(d) Water systems with uncovered finished water storage facilities shall comply with the requirements to cover the facility as described in s. NR 810.28. Finished water is that water which has received all required treatment.

(e) Water systems required to provide additional treatment for Cryptosporidium shall implement microbial toolbox options that are designed and operated as described in ss. NR 810.41 to 810.46.

(f) Water suppliers for water systems shall comply with the applicable recordkeeping and reporting requirements described in ss. NR 810.39 and 810.40.