Inspection report number 06. All distribution water system chemical injection equipment must be constructed and installed in accordance with recommended engineering practices.
Inspection report number 04; critical item. The halogenation injection equipment must provide continuous halogenation of the potable water distribution system and must maintain a free residual halogen of ≥ 0.2 mg/L (ppm) and ≤ 5.0 mg/L (ppm) throughout the distribution system.
5.4.1.2.2 Controlled
Inspection report number 08. The amount of chemicals injected into the potable water system must be analyzer controlled.
5.4.1.2.3 Halogen Backup Pump
Inspection report number 06. At least one backup halogen pump must be installed with an active, automatic switchover feature to maintain the free residual halogen in the event that the primary pump fails, an increase in demand occurs, or the low chlorine alarm sounds.
5.5 Potable Water System Halogen Monitoring
5.5.1 Halogen Analyzer-Chart Recorder
5.5.1.1 Installation
5.5.1.1.1 Distant Point
Inspection report number 06. A halogen analyzer-chart recorder must be installed at a distant point in the potable water distribution system where a significant water flow exists and represents the entire distribution system. In cases where multiple distribution loops exist, and no pipes connect the loops, there must be an analyzer and chart recorder for each loop.
5.5.1.1.2 Data Logger
Electronic data loggers with certified data security features may be used in lieu of chart recorders.
5.5.1.2 Operation
5.5.1.2.1 Maintenance
Inspection report number 06. The halogen analyzer-chart recorder must be properly maintained, and operated in accordance with the manufacturer’s instructions.
A manual comparison test must be conducted daily to verify calibration. Calibration must be made whenever the manual test value is > 0.2 ppm higher or lower than the analyzer reading.
5.5.1.2.2 Calibration
Inspection report number 06. The daily, manual comparison test or calibration must be recorded either on the recorder chart or in a log.
5.5.1.2.3 Accuracy
Inspection report number 06. The free residual halogen measured by the halogen analyzer must be ±0.2 mg/L (ppm) of the free residual halogen measured by the manual test.
5.5.1.2.4 Test Kit
Inspection report number 06. The halogen test kit used to calibrate the halogen analyzer must be accurate to within 0.2 mg/L (ppm) for halogen and graduated in increments no greater than 0.2 mg/L (ppm) in the range of free residual halogen normally maintained in the potable water system.
Ensure that all reagents used with the test kit are within the expiration date.
Where available, ensure that appropriate secondary standards are onboard for electronic test kits to verify test kit operation.
Inspection report number 06. Halogen analyzer-chart recorder charts must have a range of 0.0 to 5.0 mg/L (ppm) and have a recording period of, and limited to, 24 hours.
5.5.2.1.2 Data Logger
Inspection report number 06. Electronic data loggers with certified data security features used in lieu of chart recorders must produce records that conform to the principles of operation and data display required of the analog charts, including printing the records.
5.5.2.1.3 Increments
Inspection report number 06. Electronic data logging must be in increments of ≤15 minutes.
5.5.2.2 Operation
5.5.2.2.1 Charts
Inspection report number 06. Halogen analyzer-chart recorder charts must be changed, initialed, and dated daily. Charts must contain notations of any unusual events in the potable water system.
Inspection report number 06. Halogen analyzer-chart recorder charts must be retained for at least 12 months and must be available for review during inspections.
5.5.2.2.3 Chart Review
Inspection report number 06. Records from the halogen analyzer-chart recorder must verify the free residual halogen of ≥ 0.2 mg/L (ppm) and ≤ 5.0 mg/L (ppm) in the water distribution system for at least 16 hours in each 24-hour period since the last inspection of the vessel.
5.5.3 Manual Halogen Monitoring
5.5.3.1 Equipment Failure
5.5.3.1.1 Every 4 hours
Inspection report number 06. Free residual halogen must be measured by a manual test kit at the halogen analyzer at least every 4 hours in the event of equipment failure.
5.5.3.1.2 Recording
Inspection report number 06. Manual readings must be recorded on a chart or log, retained for at least 12 months, and available for review during inspections.
5.5.3.1.3 Limit
Inspection report number 06. Repairs on malfunctioning halogen analyzer-chart recorders must be completed within 10 days of equipment failure.
5.5.3.1.4 Alarm
Inspection report number 06. Provide an audible alarm in a continuously occupied watch station (e.g., the engine control room) to indicate low and high free halogen readings at the distant point analyzer.
Inspection report number 06. A minimum of four potable water samples per month must be collected and analyzed for the presence of Escherichia coli. Samples must be collected from the forward, aft, upper, and lower decks of the vessel.
Sample sites must be changed each month ensure that all of the potable water distribution system is effectively monitored.
Follow-up sampling must be conducted for each positive test result.
Microbiological samples from ice machines and potable water storage tanks do not count towards the monthly routine distribution system monitoring.
5.6.1.1.2 Analysis
Inspection report number 06. Samples must be analyzed utilizing a method accepted in Standard Methods for the Examination of Water and Wastewater.Test kits, incubators, and associated equipment must be operated and maintained in accordance with the manufacturers’ specifications.
5.6.1.2 Records
5.6.1.2.1 Records
Inspection report number 06. Sample results must be maintained onboard the vessel for at least 12 months, and must be available for review during inspections.
