Section 64535.4 - Determining Disinfectant Residuals Compliance(a) During the first year of monitoring for disinfection residuals under section 64534.4 the system shall comply with the following: (1) The sum of the first quarter's results, divided by four, shall not exceed the MRDLs specified in section 64533.5;(2) The sum of the first and second quarter's results, divided by four, shall not exceed the MRDLs specified in section 64533.5; and(3) The sum of the first, second, and third quarter's results, divided by four, shall not exceed the MRDLs specified in section 64533.5.(b) Chlorine and chloramines MRDL compliance is determined as follows: (1) Compliance shall be based on a running annual arithmetic average, computed quarterly, of monthly averages of all samples collected by the system under section 64534.4(a). If the average covering any consecutive four-quarter period exceeds the MRDL, the system is in violation of the MRDL and shall notify the public pursuant to sections 64463, 64463.4, and 64465, including language in appendix 64465-G, in addition to reporting to the State Board pursuant to sections 64537 through 64537.6; and(2) In cases where systems switch between the use of chlorine and chloramines for residual disinfection during the year, compliance shall be determined by including together all monitoring results of both chlorine and chloramines. Reports submitted pursuant to sections 64537 through 64537.6 shall clearly indicate which residual disinfectant was analyzed for each sample.(c) Compliance for chlorine dioxide shall be based on consecutive daily samples collected by the system under section 64534.4(b). (1) If any daily sample taken at the entrance to the distribution system exceeds the MRDL, and one (or more) of the three samples taken in the distribution system exceed the MRDL, the system is in violation of the MRDL and shall take immediate corrective action to reduce the concentration of chlorine dioxide to a level below the MRDL. The system shall notify the State Board within 48 hours of the determination, notify the public pursuant to the procedures for acute health risks in sections 64463, 64463.1, and 64465, including language in appendix 64465-G, in addition to reporting to the State Board pursuant to sections 64537 through 64537.6. Failure to take samples in the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system is also an MRDL violation and the system shall notify and report as described in this paragraph;(2) If any two consecutive daily samples taken at the entrance to the distribution system exceed the MRDL and all distribution system samples taken are less than or equal to the MRDL, the system is in violation of the MRDL and shall take corrective action to reduce the concentration of chlorine dioxide to a level below the MRDL at the point of sampling. The system shall notify the public pursuant to the procedures for nonacute health risks in sections 64463, 64463.4, and 64465, including language in appendix 64465-G, in addition to reporting to the State Board pursuant to sections 64537 through 64537.6. Failure to monitor at the entrance to the distribution system the day following an exceedance of the chlorine dioxide MRDL at this site is also an MRDL violation and the system shall notify and report as described in this paragraph.Cal. Code Regs. Tit. 22, § 64535.4
1. New section filed 5-18-2006; operative 6-17-2006 (Register 2006, No. 20).
2. Amendment of section and NOTE filed 5-22-2012; operative 6-21-2012 (Register 2012, No. 21).
3. Amendment of subsections (a)(1)-(3) filed 5-28-2014; operative 7-1-2014 (Register 2014, No. 22).
4. Change without regulatory effect amending subsections (a)(1) and (c)(1)-(2) and amending NOTE filed 6-2-2015 pursuant to section 100, title 1, California Code of Regulations (Register 2015, No. 23). Note: Authority cited: Sections 116271, 116350 and 116375, Health and Safety Code. Reference: Sections 116350, 116450 and 116460, Health and Safety Code.
1. New section filed 5-18-2006; operative 6-17-2006 (Register 2006, No. 20).
2. Amendment of section and Note filed 5-22-2012; operative 6-21-2012 (Register 2012, No. 21).
3. Amendment of subsections (a)(1)-(3) filed 5-28-2014; operative 7/1/2014 (Register 2014, No. 22).
4. Change without regulatory effect amending subsections (a)(1) and (c)(1)-(2) and amending Note filed 6-2-2015 pursuant to section 100, title 1, California Code of Regulations (Register 2015, No. 23).