Wisconsin Administrative Code › Department of Natural Resources › NR 800 - Environmental Protection - Water Supply › Chapter NR 809 - Safe Drinking Water › Subchapter III - Maximum Contaminant Levels, Maximum Residual Disinfectant Levels, Monitoring, Analytical Requirements and Control of Disinfection Byproducts, Disinfection Residuals and Stage 1 and Stage 2 DBP › Section NR 809.60 - General requirements for Stage 2 DBP disinfection byproducts control

Current through June 24, 2024
(1) GENERAL.
				  The following establish monitoring and other requirements for achieving
				  compliance with maximum contaminant levels based on locational running annual
				  averages (LRAA) for total trihalomethanes (TTHM) and haloacetic acids five
				  (HAA5), and for achieving compliance with maximum residual disinfectant levels
				  for chlorine and chloramine for certain consecutive systems.
(2) APPLICABILITY. A public water system is
				  subject to these requirements if the public water system is a community water
				  system or a nontransient noncommunity water system that uses a primary or
				  residual disinfectant other than ultraviolet light or delivers or receives
				  water that has been treated with a primary or residual disinfectant other than
				  ultraviolet light.
(3) SCHEDULE.
				  Public water systems shall comply with the requirements on the schedule in
				  Table X based on public water system population:
Table X
Public Water System
								  Population
Monitoring Compliance
								  Dates:1
Public water systems that are not part of a
								  combined distribution system and public water systems that serve the largest
								  population in the combined distribution system
(1) PWS serving >= 100,000
April 1, 2012.
(2) PWS serving 50,000-99,999
October 1, 2012.
(3) PWS serving 10,000-49,999
October 1, 2013.
(4) PWS serving < 10,000
October 1, 2013 if no
Cryptosporidium
monitoring is required under s.
								  NR 809.331(1)
								  (d), or
October 1, 2014 if
Cryptosporidium
monitoring is required under s.
								  NR 809.331(1) (d)
								  or (f)
Public water systems that are part of a
								  combined distribution system
(5) Consecutive system or wholesale system
Water suppliers shall sample using the earliest
								  compliance date of all the public water systems in the combined distribution
								  system determined by the public water system with the largest population using
								  the dates indicated in (1) to (4) of this table.
1 The department
					 may grant up to an additional 24 months for compliance with MCLs and
					 operational evaluation levels if the public water system requires capital
					 improvements to comply with an MCL.
(4) MONITORING FREQUENCY. The frequency of
				  monitoring is specified in s.
				  NR 809.61(1)
				  (c), Table Y.
(a) Water suppliers for public water systems
				  required to be monitored quarterly shall begin monitoring in the first full
				  calendar quarter that includes the compliance date in the table in sub.
				  (3).
(b) Water suppliers for public
				  water systems required to be monitored at a frequency less than quarterly shall
				  begin monitoring in the calendar month recommended in the initial distribution
				  system evaluation (IDSE) report they prepared for the EPA under Subpart U of 40
				  CFR part 141 or in the calendar month identified in the monitoring plan
				  developed under s.
				  NR
				  809.62 which shall be no later than 12 months after
				  the compliance date in the table in par. (3).
(c) Water suppliers for public water systems
				  required to be monitored quarterly, shall make compliance calculations at the
				  end of the fourth calendar quarter that follows the compliance date and at the
				  end of each subsequent quarter or earlier if the LRAA calculated based on fewer
				  than four quarters of data would cause the MCL to be exceeded regardless of the
				  monitoring results of subsequent quarters.
(d) If the public water system is required to
				  be monitored at a frequency that is less than quarterly, the water supplier
				  shall make compliance calculations beginning with the first compliance sample
				  taken after the compliance date.