Louisiana Administrative Code › Title 51 - PUBLIC HEALTH-SANITARY CODE › Part XII - Water Supplies › Chapter 11 - Surface Water Treatment Rule › Subchapter A - General Requirements and Definitions › Section XII-1109 - Calibrationdra/Validation of Disinfectant Residual Analyzers

Current through Register Vol. 50, No. 6, June 20, 2024
A. Validation of Bench Top Disinfectant
				  Residual Spectrophotometers/Colorimeters. The accuracy of bench top
				  spectrophotometers/colorimeters used for disinfectant residual monitoring,
				  particularly for validation of continuous disinfectant residual monitors, shall
				  be determined at a frequency of no less than once every 90 days by use of a
				  NIST traceable standard solution which has been obtained from an approved
				  source (e.g., certificate of analysis by manufacturer). Deviations of +-10
				  percent or more shall be cause for calibrationdra of the
				  equipment. The instruments shall be calibrated in accord with the
				  manufacturer's instructions. After calibrationdra the
				  instrument's accuracy shall be validated prior to return to service.
B. Validation/Standardization Using Other
				  Methods. For approved methods for disinfectant residual analysis other than
				  spectrophotometric/colorimetric methods, validation/standardization of
				  disinfectant residual analyzers shall be performed in accord with procedures
				  outlined in the particular method [see §1105 C].
C. Validation of Continuous Disinfectant
				  Residual Monitors. The accuracy of residual disinfectant measurements from any
				  continuous disinfectant residual monitor shall be validated weekly. Validation
				  shall be performed by collecting a grab sample from the tubing supplying water
				  to the monitor (e.g., via a tee connection which is normally capped or valved
				  closed) at a location immediately upstream (less than 5 feet) of the continuous
				  disinfectant residual monitor. Such grab sample shall be analyzed using a bench
				  top spectrophotometer/colorimeter which has been calibrated according to §1109.
				  A of this Chapter. If the spectrophotometer/colorimeter reading indicates +-10
				  percent or more deviation as compared to the continuous disinfectant residual
				  monitor reading, the cause of the disparity shall be investigated and resolved
				  within five working days. In the meantime, grab samples shall be collected and
				  analyzed every two hours as per §1125. B of this Chapter. The accuracy of
				  residual disinfectant measurements from any replacement instrument shall be
				  validated prior to service or return to service.
D. Records of Calibrations/Validations.
				  Records of calibrations/validations on each bench top
				  spectrophotometer/colorimeter used for disinfectant residual monitoring and on
				  each continuous disinfectant residual monitor shall be maintained for at least
				  three years, as follows.
1. Records of bench
				  top spectrophotometers/colorimeters shall include meter location, meter
				  identification, dates and results of NIST traceable standard solution, dates of
				  calibrationdra/validation and the name of the person
				  performing the calibrationdra/validation.
2. Records of continuous disinfectant
				  residual monitors shall include meter location, unique meter identification
				  (e.g., model and serial number), dates and results of calibration/validation,
				  and the corrective actions taken when deviations of +-10 percent or more
				  occur.