A Marlborough council will be chlorinating some drinking water - to stop the spread of Covid-19

The Tasman District Council has announced it'll add chlorine to its Richmond and Riwaka supplies.

Richmond Councillor Dana Wensley says both supplies have had contamination incidents in recent years.

She says it's just a precaution.

But Wensley says if there was a contamination incident with a water-borne disease like Covid-19 on the loose - it could cause significant harm in their community.