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 I - General Operations › Section NR 810.12 - Distribution system loss of pressure

Current through June 24, 2024
The water supplier for community water systems shall be
					 responsible for taking corrective action when positive distribution system
					 pressure is lost in an area affecting 25% or more of the overall distribution
					 system or in an entire pressure zone. In addition to restoring system pressure,
					 the water supplier shall perform all of the following:
(1) Notify the appropriate regional office of
				  the department as soon as possible, but no later than one working day after the
				  loss of pressure, as to the extent of the problem, cause and corrective actions
				  taken.
(2) Start emergency
				  disinfection of the water supply if the water system is not already
				  continuously disinfected. At a minimum, the free chlorine residual shall be 0.2
				  mg/l at the entry point to the distribution system and detectable throughout
				  the distribution system or the total combined chlorine residual shall be 1.0
				  mg/l at the entry point and detectable throughout the distribution system. If
				  loss of pressure was limited to one pressure zone, the above disinfection
				  requirements may be restricted to target the affected pressure zone. Higher
				  disinfectant residuals may be required by the department if deemed necessary to
				  ensure a safe water supply. Water mains and storage facilities in the area that
				  lost pressure shall be flushed to remove contaminated water and to quickly
				  establish an adequate disinfectant residual. Emergency disinfection shall be
				  maintained until approval is obtained from the department to cease.
(3) Collect distribution system water samples
				  for bacteriological analyses from the pressure loss area as soon as adequate
				  pressure is returned to the water system. The number of samples collected shall
				  increase as the extent of problem areas increases, but in no case may less than
				  2 samples be collected. The department shall be contacted to determine the
				  number of samples and sampling locations. The water supplier shall comply with
				  s.
				  NR
				  809.31 when water system sampling indicates the
				  presence of coliform organisms.
(4)
				  Issue an immediate boil water notice to all affected water consumers unless it
				  is determined by the department that an acute threat to public health does not
				  exist. The boil water notice shall be maintained until approval is obtained
				  from the department to cease. In this subsection "boil water notice" means a
				  special type of public notice that informs consumers that the water is
				  bacteriologically unsafe and should be boiled prior to consumption. A boil
				  water notice shall include all the following information:
(a) The water has tested bacteriologically
				  unsafe for drinking.
(b) All water
				  used for washing of eating utensils, drinking, or cooking should be boiled at a
				  rolling boil for at least one minute.
(c) Ice and any beverages prepared with
				  unboiled water should be discarded.
(d) Precautions listed in subd. 1 to 3 are in
				  effect until further notice.