Domestic water storage tank annual maintenance checklist

Owner and occupants told of the outage and bypass

Owner and affected occupants told the outage window before isolation, bypass or alternate supply confirmed feeding the building at pressure first.

Fill and outlet valves closed and feeds locked out

Any fill solenoid, heat tracing, mixer or pump locked and tagged, valves tagged shut. Locks come off, by whoever hung them, only once everyone is out and the hatch is shut.

Any tank entry made only under a confined-space permit

Atmosphere tested, attendant posted, rescue plan in place and permit signed before anyone enters. A tank inspected from the hatch needs no entry.

Tank drained and inspected inside for sediment and biofilm

Interior cleaned of sediment and biofilm, coating or liner sound with no corrosion or delamination, no standing debris left in the bottom.

Inlet, outlet and overflow fittings checked inside the tank

Inlet, outlet and overflow pipes, internal supports and any ladder free of corrosion, scale and loose mounts, outlet and drain openings clear of sediment.

Fill valve and level sensors serviced with the tank down

Float, altitude or solenoid fill valve cleaned and serviced per the manufacturer, floats or probes cleaned and moving freely, worn seats or seals noted for replacement.

Cleaning and disinfection method matched to the authority

Qualified contractor's written method follows the applicable AWWA standard family and the water authority's or health department's requirements, on file before work.

Sanitizing agent label checked for potable water use

Product label shows certification for drinking water use, within its date, and matches the agent named in the written disinfection method.

Tank disinfected and cleared by sample before return to service

Tank disinfected and flushed per the manufacturer's and code guidance, and a clearing sample confirmed acceptable before the tank is put back on the potable supply.

Disinfection water dechlorinated before discharge

Flush and drain-down water dechlorinated before discharge, then sent only where the water authority or local rules allow.

Lab report for the clearing sample on file before the outlet opens

The certified laboratory report for that clearing sample on file and reviewed with the owner before the outlet opens. A field kit reading alone never returns the tank to service.

Bypass closed and tank returned to service on its controls

Outlet reopened, bypass closed, every lock and tag cleared by whoever hung it, tank filling and holding its working band on automatic.

High and low level alarms proven where fitted

Beyond the quarterly review: monitoring operator told first, level driven or sensor lifted to each alarm point, alarm seen locally and remotely where monitored, then reset.

Turnover and disinfection records confirmed current

Disinfection and sample results filed and current, turnover rate reviewed against demand, level set points confirmed to keep the water moving, log up to date.

Service results logged to the water management plan

Post-service residual and temperature, alarm results and next cleaning date logged, and the record sent to the health department where it requires one.