California Code of Regulations › Title 22 - Social Security › Division 4 - Environmental Health › Chapter 15 - Domestic Water Quality and Monitoring Regulations › Article 3 - Primary Standards-Bacteriological Quality › Section 64423 - Routine Sampling

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) A
				  public water system shall collect routine bacteriological water samples as
				  follows:
(1) The minimum number of samples
				  for community water systems shall be based on the known population served or
				  the total number of service connections, whichever results in the greater
				  number of samples, as shown in Table 64423-A;
(2) The minimum number of samples for
				  nontransient-noncommunity water systems shall be based on the known population
				  served as shown in Table 64423-A during those months when the system is
				  operating;
(3) The minimum number
				  of samples for transient-noncommunity water systems using only groundwater (not
				  GWUDI) and serving 1000 or fewer persons a month shall be one in each calendar
				  quarter during which the system provides water to the public;
(4) The minimum number of samples for
				  transient-noncommunity water systems using groundwater (not GWUDI) and serving
				  more than 1000 persons during any month shall be based on the known population
				  served as shown in Table 64423-A. For any quarter the system serves 1000 or
				  fewer persons in each month and uses only groundwater (not GWUDI), and if the
				  criteria in subsections (c)(2)(A) and (B) are met, the system may submit a
				  request to the State Board to monitor in accordance with paragraph (3). The
				  request shall include:
(A) Historical data
				  that demonstrates the system has served 1000 or fewer persons in each month of
				  the calendar quarter for which the request is being made; and
(B) A revised bacteriological sample siting
				  plan with an updated sampling schedule;
(5) The minimum number of samples for
				  transient-noncommunity water systems using approved surface water shall be
				  based on the population served as shown in Table 64423-A. A system using
				  groundwater under the direct influence of surface water shall begin monitoring
				  at this frequency by the end of the sixth month after the State Board has
				  designated the source to be approved surface water;
(6) The minimum number of samples for
				  seasonal systems, and in lieu of paragraphs (2) through (5), shall be based on
				  the population served as shown in Table 64423-A during those months when the
				  system is operating;
(7) Samples
				  shall be collected at regular time intervals throughout the month, except that
				  a system using only groundwater (not GWUDI) which serves 4,900 persons or fewer
				  may collect all required samples on a single day if they are taken from
				  different sites;
(8) At least the
				  minimum number of samples shall be taken even if the system has had an
E. coli
MCL violation or has exceeded the coliform treatment
				  technique triggers in Section
				  64426.7; and
(9) More than the minimum number of samples
				  may be taken provided the samples are included in the bacteriological sample
				  siting plan developed pursuant to Section
				  64422.