Mid Yell is one of the Shetland communities set to benefit

Scottish Water is set to invest the money in what it said was a demonstration of its commitment to remoter areas.

The upgrades could range from equipment maintenance to larger overhauls.

The treatment works are Unst, Mid Yell, Sandy Loch, Cullivoe, Whalsay, Bressay, Eela, South Yell, Fetlar, Skerries, Fair Isle, Foula and Papa Stour.

Bad weather

Malcolm Hulme, Scottish Water co-ordinator for Shetland, said: "We have already invested heavily to improve drinking water supplies and waste water treatment.

"The upgrades announced will safeguard supplies for around 20,000 people.

"Customers throughout Shetland deserve modern supplies that meet the latest standards."

The upgrades announced are aimed at improving the quality of drinking water, including reducing instances where bad weather stirs up sediment within lochs and streams, causing supplies to appear coloured.

It is hoped that work will begin next year.