WAC 246-290-638   Analytical requirements.  (1) The purveyor shall ensure that only qualified persons conduct measurements for pH, temperature, turbidity, and residual disinfectant concentrations. In this section, qualified shall mean:

     (a) A person certified under chapter 246-292 WAC;

     (b) An analyst, with experience conducting these measurements, from the state public health laboratory or another laboratory certified by the department; or

     (c) A state or local health agency professional experienced in conducting these measurements.

     (2) The purveyor shall ensure that measurements for temperature, turbidity, pH, and residual disinfectant concentration are made in accordance with "standard methods," or other EPA approved methods.

     (3) The purveyor shall ensure that samples for coliform and HPC analysis are:

     (a) Collected and transported in accordance with department-approved methods; and

     (b) Submitted to the state public health laboratory or another laboratory certified by the department to conduct the analyses.

     (4) Turbidity monitoring.

     (a) The purveyor shall equip the system's water treatment facility laboratory with a:

     (i) Bench model turbidimeter; and

     (ii) Continuous turbidimeter and recorder if required under WAC 246-290-664 or 246-290-694.

     (b) The purveyor shall ensure that bench model and continuous turbidimeters are:

     (i) Designed to meet the criteria in "standard methods," EPA Method 180.1, or Great Lakes Instruments Method 2; and

     (ii) Properly operated, calibrated, and maintained at all times in accordance with the manufacturer's recommendations.

     (c) The purveyor shall validate continuous turbidity measurements for accuracy as follows:

     (i) Calibrate turbidity equipment based upon a primary standard in the expected range of measurements; and

     (ii) Verify continuous turbidimeter performance on a weekly basis, not on consecutive days, with grab sample measurements made using a properly calibrated bench model turbidimeter.

     (d) When continuous turbidity monitoring equipment fails, the purveyor shall measure turbidity on grab samples collected at least every four hours from the combined filter effluent and individual filters while the system serves water to the public and the equipment is being repaired or replaced. The purveyor shall have continuous monitoring equipment on-line within five working days of failure.

     (5) Purveyors monitoring for Cryptosporidium or E. coli as required under 40 CFR 141.701 shall collect samples and have them analyzed under 40 CFR 141.704 and 141.705.



[Statutory Authority: RCW 70.119A.180 and 43.20.050. 08-03-061, § 246-290-638, filed 1/14/08, effective 2/14/08. Statutory Authority: RCW 43.20.050 (2) and (3) and70.119A.080 . 03-08-037, § 246-290-638, filed 3/27/03, effective 4/27/03. Statutory Authority: RCW 43.02.050 [43.20.050]. 99-07-021, § 246-290-638, filed 3/9/99, effective 4/9/99. Statutory Authority: RCW 43.20.050. 93-08-011 (Order 352B), § 246-290-638, filed 3/25/93, effective 4/25/93.]