Manage an E. coli detection at the Numurkah reservoir

What is going on

The laboratory has phoned through a presumptive E. coli detection of 3 per 100 millilitres on yesterday's verification sample at reservoir R-19 outlet in Numurkah, which serves about 4,800 people including a hospital, two schools and an aged care home. The free chlorine residual at the same site was 0.22 milligrams per litre, at the alert level. R-19 was the subject of a low residual incident in August and booster dosing was commissioned. The Control Centre and Water Quality Manager is running the event as a full exercise and is playing the health regulator and the Managing Director. You must work the procedure as if the event were real, from first notification through to the clearance plan and the incident report.

Your brief

Take control of the water quality incident under the Water Quality Incident Response Procedure, set the incident level, direct resampling and corrective actions, prepare the health regulator notification and a draft boil water advisory, brief critical customers, set clearance criteria and complete the Water Quality Incident Report Template.

Work through it

You do not need to do it all. Doing a few of these will show you what the work is like. Your ticks and notes stay on this device.

• Read the Water Quality Incident Response Procedure and the Drinking Water Quality Policy, and record the immediate actions, the incident levels and the notification obligations that apply to an E. coli detection.
• Log the event in the WHS and Environmental Incident Register as a water quality incident with time, site, result and population affected, and set and justify the incident level.
• Direct resampling at R-19 outlet, upstream at the bore field outlet and at two downstream reticulation sites with chlorine residual checks, and enter each sample in the Water Quality Sampling Register.
• Review the reticulation residual critical control point, the August incident INC-26-108 and the booster dosing performance, and identify the likely cause and the corrective actions to direct, such as increased boosting, reservoir turnover or flushing.
• Prepare the notification to the health regulator with the location, result, population, actions taken and proposed next steps, and record the time it is made and to whom.
• Draft the boil water advisory in plain language with the area defined in street terms, the actions customers must take and the next update time, and list the channels it will be issued through.
• Prepare a briefing for the hospital, schools and aged care home and record who will deliver it and when.
• Set the clearance criteria and the sampling plan to lift the advisory, and complete the Water Quality Incident Report Template with the timeline, cause, actions and lessons for the debrief.

What someone in this role would produce

• Incident register entry with level and justification
• Resampling plan and register entries
• Health regulator notification
• Draft boil water advisory and critical customer briefing
• Completed Water Quality Incident Report