This is delivering significant improvements and is upgrading much of the infrastructure which was built in Victorian times

Ross Finnie, environment minister

"Reaching these standards involves working together with water authorities, councils and non government organisations as well as the farming and industrial sectors on a range of issues."

He added: "On the water and waste water treatment side of the equation the water authorities are nearing the completion of an unprecedented three-year investment programme costing �1.8 billion.

"This is delivering significant improvements and is upgrading much of the infrastructure which was built in Victorian times."

West of Scotland Water said the scheme, which has involved complex civil engineering work, will play a major part in cleaning up the beaches.

Scale of investment

The body said that up until as recently as 1997, unscreened raw sewage was being pumped into the bay from four short sea outfall pipes leading to sewage debris frequently washing up ashore.

Meanwhile, sewage from storm overflow pipes was also being discharged unchecked into the River Ayr.

The scheme will now mean that effluent from every household and business in the area, as well as several storm overflows, will be collected in one massive sewer pipe and transferred to Irvine for treatment.

Professor Alan Alexander, chairman of West of Scotland Water, said: "This �48 million project illustrates the scale of investment that West of Scotland Water is undertaking to play its part in improving the aquatic environment of the west coast.

"The water industry in Scotland has suffered from a historic under investment in new infrastructure, which has led to the totally unacceptable practice of raw sewage being pumped out to sea, in places such as Ayr, as recently as five years ago.

"It is only now major investments, such as the Ayr Sewerage Scheme, are coming on stream to reverse this appalling practice."