Before revision: The preferred method of firewater containment is to use pneumatic bladders/drain stoppers that block the outflow from the drain or pneumatic non-return valves, both of which can convert the drains into containment vessels (called sumps) from which the firewater can be pumped away into tankers for safe disposal .
After revision: or stored temporaritily in mobile firewater tanksThe preferred method of firewater containment is to use pneumatic bladders/drain stoppers that block the outflow from the drain or pneumatic non-return valves, both of which can convert the drains into containment vessels (called sumps) from which the firewater can be pumped away into tankers for safe disposal .