"There is a risk that the water in Olsfors and Hultafors is unfit for consumption", writes Bollebygd Municipality on its website and urges residents to only use the water for flushing toilets for the time being.
On Tuesday, the municipality instead began placing out water tanks, reports P4 Sjuhärad.
It was just before 11 am on Tuesday that it was discovered that the water reservoir was unlocked. The municipality fears that unauthorized persons may have gained access.
The recommendation not to drink the water will apply until all test results have been received, which may take up to two weeks.
We don't know exactly what happened. But our technicians are absolutely sure that it was locked when they left, says Ulf Krüger, technical manager at the municipality, to Borås Tidning.
The police report that they have filed a report on suspected sabotage.
