Coliforms [by first stage in monitoring by enzyme What to measure or E. coli substrate method]; or Heterotrophic Plate Count (HPC). observe: organic carbon (TOC). Disinfection by-products. Complaints of taste and odour from consumers. When the first stage [coliform] in monitoring in How often: E. coli water leaving the treatment plant using the enzyme substrate method indicates the presence of significant numbers of coliforms. TOC monitoring is for process control, and can be carried out at a frequency considered appropriate by the supplier (at monthly). Results need to be recorded to meet legislative What to do with the requirements or to allow water safety plan performance results: 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 laboratory results or indicate that poor water quality is reaching customers, then review the procedures for managing the trace organics removal process. Evaluate the monitoring results to see if the water safety plan needs modification eg, preventive measures are up – to date; and changes to the trace organics removal process are recognised in the plan. Manager designated responsible for the water supply. Responsibility:
What to measure or observe: Coliforms [by first stage in E. coli monitoring by enzyme substrate method]; or Heterotrophic Plate Count (HPC). organic carbon (TOC). Disinfection by-products. Complaints of taste and odour from consumers. How often: When the first stage [coliform] in monitoring E. coli in water leaving the treatment plant using the enzyme substrate method indicates the presence of significant numbers of coliforms. TOC monitoring is for process control, and can be carried out at a frequency considered appropriate by the supplier (at monthly). What to do with the results: Results need to be recorded 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 laboratory results or indicate that poor water quality is reaching customers, then review the procedures for managing the trace organics removal process. Evaluate the monitoring results to see if the water safety plan needs modification – eg, preventive measures are up to date; and changes to the trace organics removal process are recognised in the plan. Responsibility: Manager designated responsible for the water supply.
treatment-trace-organics-removal-feb14-v2.docx