Risk Information Table Reliable information about water quality is essential for the proper management of a water supply. Knowledgeable and skilled staff are also essential for minimising the public health risks associated with water supplies. Please read the staff training Guide (Guide G1) as well as this Guide. Abbreviations: DWSNZ – Drinking-Water Standards for New Zealand Causes Preventive measures Checking preventive measures Corrective action What to check Signs that action is needed Event: INCORRECT WATER QUALITY DATA USED FOR SUPPLY MANAGEMENT Possible hazards: Germs; chemical determinands. Level of risk: High1 G2.1.1 Inappropriate/ incorrect sampling. Prepare a sampling plan (WINZ can assist here). Ensure purpose of taking the sample is established. Periodically review sampling plan to ensure it will still achieves its purpose. Determine that the following are correct: sampling location sampling frequency sampling procedure. See the appropriate section of DWSNZ:2000 or consult WINZ if monitoring is for compliance purposes. Audit of sampling plan and sampling procedures. Poor records/ data entry checks not signed off. Unacceptable number of errors detected during audits. Process control failures. Outliers in inter-lab quality control studies. Audit of sampling plan and procedures not undertaken. Unexplained compliance test failures. Improve sampling plan. Find out the reason for taking the sample (compliance, process control, etc). Undertake review. Consult DWSNZ:2000. Ensure (check with approved laboratory in use) that the sampling container is correct and correctly preserved (if appropriate), and that sample transport procedures are satisfactory. Ensure staff carrying out sampling are properly trained. Check with laboratory. Identify staff training needs and provide training. 1 The risks associated with this event are not direct. However, without reliable information about the quality of the water being produced and distributed to consumers, good management and operational decisions to protect public health cannot be reached.
Causes Preventive measures Checking preventive measures Corrective action What to check Signs that action is needed Event: INCORRECT WATER QUALITY DATA USED FOR SUPPLY MANAGEMENT cont’d G2.1.2 Inadequate/ incorrect test equipment or incorrectly calibrated test equipment. Use equipment that meets the requirements of the Referee Methods (or methods calibrated against the Referee Method) contained in DWSNZ:2000. Carry out routine maintenance as specified by the manufacturer. Undertake calibration procedures as set out in the Referee Method, or as specified by the manufacturer, or have them carried out independently. Audit of equipment calibration and maintenance records. quality control results. Poor comparison performance. No, or incomplete, record of calibration and maintenance. Consult Referee Method for guidance concerning equipment specifications. Put maintenance schedule in place. Consult Referee Method for guidance concerning calibration. G2.1.3 Inadequate reagents Ensure shelf-lives of reagents are known and date at which they need to be prepared again noted on the container. Ensure reagents are stored appropriately (usually this is in the dark and cool). Maintain records for the preparation of reagent solutions and calibration standards. Preparation calculations should be independently Cross check reagent quality by repeat analysis of a sample using old and newly-prepared reagents when new reagents have been prepared. quality control results. Reagent preparation records. Poor comparison performance. Reagent preparation records indicate reagents are too old. Consult Referee Method for reagent stability information. Provide and use appropriate storage. Start keeping records. G2.1.4 Inappropriate method or incorrect calibration. See DWSNZ:2000 to find out which methods can be used, and if necessary use the referee method to validate an alternative method. Ensure that the calibration procedures specified in the method are followed. Ensure staff are adequately trained in calibration procedures required in the method. quality control results. Poor comparison performance. Check DWSNZ:2000 for acceptable methods. Improve documentation of method. Identify staff training needs and provide training. G2.1.5 Inadequate or incorrect monitoring records. Undertake regular audits of records. Ensure staff are trained in the maintenance of records. Ensure that independent checks are made on data entry. Audit of monitoring and training records Poorly kept monitoring records (eg, sampling location, date, sample identification number, etc) Start audits. Identify staff training needs and provide training. Start independent checks. laboratory laboratory
Modify the water safety plan if necessary. Responsibility: Manager designated responsible for the water supply. Water Safety Plan Performance Assessment To make sure that your supply’s water safety plan (formerly known as a Public Health Risk Management Plan, PHRMP) is working properly, periodic checks are needed. The overview document outlines what needs to be done. The following table provides the detailed information for checking this particular supply element. What to measure or observe: Record audits. Maintenance and calibration logs. Inter-laboratory study data. Internal quality control checks. How often: Records should be audited every six months. Inter-laboratory study data should be reviewed after each study. Quality control checks should be undertaken at the frequency required by the accreditation registration schedule. What to do with the results: Record results to meet legislative requirements or to allow water safety plan performance assessment. The WINZ database is good for this. The collected data need to be periodically reviewed to see whether problems with this supply element are developing. This should be done as frequently as the manager responsible considers necessary to minimise risk to public health arising from this supply element. Should this review show any unusual incidents, indicate that proper procedures are not being carried out, highlight poor results or indicate that poor water quality is reaching customers, then review the procedures for managing monitoring activities. Evaluate the monitoring results, and any actions taken as the result of having to implement a contingency plan, to see if the water safety plan needs modification – eg, preventive measures are up to date; the contingency plan steps are still adequate; and changes to monitoring protocols are recognised in the plan.