California Code of Regulations › Title 22 - Social Security › Division 4 - Environmental Health › Chapter 15 - Domestic Water Quality and Monitoring Regulations › Article 5.5 - Primary Standards-Organic Chemicals › Section 64445 - Initial Sampling-Organic Chemicals

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) Each community and
				  nontransient-noncommunity water system shall collect four quarterly samples
				  during the year designated by the State Board of each compliance period
				  beginning with the compliance period starting January 1, 1993, from each water
				  source at a site prior to any treatment and test for all applicable organic
				  chemicals listed in Table 64444-A. The State Board will designate the year
				  based on historical monitoring frequency and laboratory capacity. For surface
				  sources, the samples shall be taken at each water intake. For groundwater
				  sources, the samples shall be taken at each well head. Where multiple intakes
				  or wells draw from the same water supply, the State Board will consider
				  sampling of representative sources as a means of complying with this section.
				  Selection of representative sources shall be based on evidence which includes a
				  hydrogeological survey and sampling results. Wells shall be allowed to flow for
				  a minimum of 15 minutes before sampling to insure that the samples reflect the
				  water quality of the source. In place of water source samples, a supplier may
				  collect samples at sites located at the entry points to the distribution
				  system. The samples shall be representative of each source after treatment. The
				  system shall collect each sample at the same sampling site, unless a change is
				  approved by the State Board.
(b)
				  For any organic chemical added to Table 64444-A, the water system shall
				  initiate the quarterly monitoring for that chemical in January of the calendar
				  year after the effective date of the MCL.
(c) A water system may request approval from
				  the State Board to composite samples from up to five sampling sites, provided
				  that the number of the sites to be composited is less than the ratio of the MCL
				  to the DLR in Section
				  64445.1. Approval will be based on
				  a review of three years of historical data, well construction and aquifer
				  information for groundwater, and intake location, similarity of sources, and
				  watershed characteristics for surface water. Compositing shall be done in the
				  laboratory and analyses shall be conducted within 14 days of sample collection.
(1) Systems serving more than 3,300 persons
				  shall composite only from sampling sites within a single system. Systems
				  serving 3,300 persons or less may composite among different systems up to the
				  5-sample limit.
(2) If any organic
				  chemical is detected in the composite sample, a follow-up sample shall be
				  analyzed within 14 days from each sampling site included in the composite for
				  the contaminants which were detected. The water supplier shall report the
				  results to the State Board within 14 days of the follow-up sample collection.
				  If available, duplicates of the original sample taken from each sampling site
				  used in the composite may be used instead of resampling.