Rural disinfection rebuild

The challenge

A rural system serving a few hundred connections was running disinfection equipment older than most of its operators. Dosing was manual, the residual was managed by experience rather than instrumentation, and the spare parts had stopped being made.

The board had been quoted for a full replacement twice and had declined twice, because the number was most of a year's revenue and there was nowhere to put it.

What we did

The system qualified for a USDA programme aimed at exactly this: small rural communities with a median household income below the state figure. Nobody had told them, because the people quoting the equipment were not the people who read those rules.

We staged the rebuild so the plant never stopped producing: new dosing and instrumentation first, running alongside the old train, then the changeover inside a single night, then removal. The application was written against that staging, so the cost breakdown matched how the work would actually be invoiced.

The outcome

The rebuild was delivered across one season with no boil notice and no interruption to supply. Residual is now instrumented and logged rather than judged, which is also what the state wanted to see.

The grant share meant the board could approve it out of the capital plan they already had, rather than the one they were dreading.

Equipment supplied

• Packaged disinfection skid with duty and standby trains
• Automatic dosing control with residual analysers
• Chemical storage, containment and safety equipment
• Telemetry into the existing SCADA, with alarms that reach a person

Figures are from the project file and the award documentation. The customer is not named at their request. Results depend on the site and are not a prediction for any other project.