Potable Water Reservoir Tank Lining

The challenge

A potable water reservoir tank corrodes on the inside where stored water sits against steel, and the original lining that held that corrosion back starts to break down. As the lining fails, the bare steel underneath pits and loses wall thickness, and the breakdown can carry into the water the tank is supposed to keep clean. Left untreated, the corrosion spreads, the tank can no longer protect the stored water, and it has to be taken out of the supply. The owner needed the interior brought back to a clean, protected condition with a lining suited to drinking-water contact, without replacing the tank.

Our approach

We drain and ventilate the tank, then grit-blast the interior back to clean, profiled steel so the old failing lining and the corrosion product come off and the new system bonds to bare metal. We rebuild the pitted and thinned areas with a cold-applied composite to bring the steel back to profile, working cold so the tank sees no hot work. Then we apply an immersion-grade lining keyed to potable water contact across the full interior, so the steel and the rebuilt areas sit under one continuous barrier. We finish and inspect the lining before the tank goes back into the supply.

1. Assess and mapWe enter the drained tank to map pitting, metal loss, and the condition of the old lining, and confirm the interior is suited for a drinking-water-contact system.
2. Grit-blast prepWe grit-blast the full interior to a clean, profiled surface so the failed lining and corrosion product come off and the new system bonds to bare steel.
3. Rebuild pitted steelWe rebuild the pitted and thinned areas with a cold-applied composite, restoring the steel to profile with no hot work.
4. Apply immersion liningWe apply an immersion-grade lining suited to drinking-water contact across the steel and rebuilt areas as one continuous barrier.
5. Inspect and return to serviceWe confirm the lining is sound and continuous, then hand the tank back for return to the potable water supply.