Guy N. Smith – Thirst

Guy N. Smith – Thirst (NEL, Feb. 1980)

Blurb:

It was the most deadly weedkiller ever invented.

There had already been an accident — an inquisitive child found
foaming at the mouth, clamouring for water, his body a mass of pustulating sores. Now a whole tanker-load had gone astray — crashed into a reservoir feeding one of the most densely populated areas in Britain.
It was too late to cut off the supply. They could only wait for the horror to strike.
Thousands were already doomed to the terrible, lingering death — thousands more would die in the ensuing pandemonium as the people panicked and the authorities declared martial law …