Section 812.41. Disinfection, flushing and sampling.

 

(1)   Disinfection. When a potable well is entered for the purpose of installing, replacing or repairing equipment located within the well, the well and discharge piping shall be thoroughly disinfected by the pump installer or by the person who installed the pump using sodium hypochlorite or calcium hypochlorite. Chlorine compounds having additives may not be used.

(a) The disinfectant shall be dispersed throughout the entire water column and in the water system.

(b) A chlorine solution with a minimum of 100 mg/l of chlorine shall be used to disinfect wells and water systems.

(c) The disinfectant solution shall be prepared according to s. NR 812.22 (4) and shall remain in the system at least 8 hours, except for emergency situations when water is needed without delay. A contact time of at least 30 minutes shall be provided for emergency situations.

(2)   Flushing. The pump installer or his or her agent shall thoroughly flush the system of chlorine after disinfecting and before the pump is placed in normal service.

(3)   Sampling for coliform bacteria, nitrate, and arsenic.

(a) For potable wells, the pump installer or his or her agent or the owner shall collect a water sample to be analyzed for coliform bacteria no later than 30 days following completion of the original pump installation and before the system is placed into service. Water samples shall also be collected and analyzed for coliform bacteria, nitrate and arsenic no later than 30 days after the well is entered for the purpose of measuring or diagnosing any feature or problem within the well or after the well is entered for rehabilitation, redevelopment, reconditioning, or cleaning or if the well is entered for the purpose of installing, replacing, or repairing equipment located within the well or when the casing height is raised. If the pump installer uses the well owner as the agent to collect the water samples, the pump installer shall provide the owner with laboratory designated sample bottles and department specified forms. Regardless of whom the pump installer designates to collect and submit the samples for analysis, the responsibility to ensure these tasks are completed belongs to the pump installer. Water samples shall be collected no later than 30 days after completion of the work. If the installation is completed at a time when the sample will be received at a certified laboratory later than 48 hours after the sample was collected, the sample may instead be collected no later than 30 days after the well is placed in service. If the laboratory test report indicates that any test result is invalid for any reason, including improper sample bottle, improper collection technique, or longer than 48 hours between sample collection and arrival at the laboratory, the pump installer is required to collect replacement samples no later than 30 days of receiving the invalid test report(s).

(b) Water samples for coliform bacteria analysis shall be analyzed by a laboratory certified by DATCP under ch. ATCP 77 to perform coliform bacteriological examination of drinking water provided the laboratory has an agreement with the department for electronic submission of laboratory test reports to the department no later than 30 days after completion of each analysis or be analyzed by the Wisconsin state laboratory of hygiene.

(c) Water samples for nitrate analysis shall be analyzed by a laboratory certified by the department under ch. NR 149 , to perform nitrate analysis of drinking water provided the laboratory has an agreement with the department for electronic submission of laboratory test reports to the department no later than 30 days after completion of each analysis, or be analyzed by the Wisconsin state laboratory of hygiene.

(d) Water samples for arsenic analysis shall be analyzed by a laboratory certified by the department under ch. NR 149 , to perform arsenic analysis of drinking water provided the laboratory has an agreement with the department for electronic submission of laboratory test reports to the department no later than 30 days after completion of each analysis, or be analyzed by the Wisconsin state laboratory of hygiene.

(e) The certified laboratory and pump installer shall use forms specified by the department. The pump installer shall provide the well owner with a copy of the laboratory test reports no later than 10 days after the pump installer's receipt of the reports.

(4)   Well casing pipe depth verification. When required to measure well casing pipe depth, due to lack of a confirmable well construction report, the pump installer shall enter the well details, including location, well casing pipe depth, total well depth, distances to possible contaminant sources and well owner information on a form specified by the department and shall submit the report to the department no later than 30 days after performing the verification. A copy of the report shall also be provided to the well owner no later than 30 days after performing of the verification.

History: Cr. Register, January, 1991, No. 421 , eff. 2-1-91; am. (1) (intro.), (3) (a), (c), Register, September, 1994, No. 465 , eff. 10-1-94; CR 13-099 : r. and recr. (3), cr. (4) Register September 2014 No. 705 , eff. 10-1-14.

Note

In some instances arsenic test results may be temporarily high due to turbidity increases caused by changing a pump or by chlorination following work involving entry into the well. Before pursuing remedial reaction, the well owner is advised to collect a second water sample at least 30 days after the first sample. Microsoft Windows NT 6.1.7601 Service Pack 1