A RECORD number of industrial sites across Scotland have been named and shamed by the government's green watchdog for failing to curb pollution risks.

The Scottish Environment Protection Agency (Sepa) has fingered 25 sites for their poor performances in 2007. They comprise 11 waste facilities, eight animal businesses, and six energy or manufacturing plants, including well-known companies such as Shanks, Ineos, ScottishPower and Lafarge.

Many of the sites have broken environmental rules, leaked hazardous pollution or spread nasty smells. Some have been taken to court or been hit with legal enforcement action, while others have been guilty of management failures.

For the fourth year in a row, Sepa has released details of its "operator performance assessments" for Scotland's main industrial enterprises. The total number of sites officially rated as "unsatisfactory" for failing to properly manage pollution risks is the highest to date.

While the number of sites assessed is rising, so is the proportion failing. In 2007, with 25 out of 313 sites declared unsatisfactory, the failure rate was 8%. This compares to 6% in 2006, when 17 of 277 sites failed.

As many as 11 of the sites failing in 2007 were repeat offenders, with four having failed twice before. This has prompted calls for Sepa to consider closing down the worst offenders.

"Companies that repeatedly fail these pollution assessments are a blot on Scotland's green reputation - and so harm our economy," said Duncan McLaren, chief executive of Friends of the Earth Scotland.

"Sepa has the power to shut down repeat offenders by withdrawing their permits. It's time it took decisive action."

One of the sites assessed as unsatisfactory three times is the Sacone animal incinerator at Brechin in Angus. According to Sepa, it suffered "numerous breaches" of its operating permit in 2007 and was fined £10,000 in December for spilling animal waste.

Another three-time offender is the oil waste treatment plant run by Total Waste Management Alliance in Peterhead, against which Sepa took enforcement action in 2007. Neither company responded to requests for comments.

A plant manufacturing carbon fibres run by the German company SGL at Muir of Ord in Ross-shire has also been rated as unsatisfactory for three years. In 2007, it suffered "numerous incidents" including an explosion in an oven, Sepa said.

But, according to SGL's site director, John Pritchard, the problems were in the past, thanks to a £2.5 million investment earlier this year.

The other facility to have performed badly for three years was the Garlaff landfill at Skares in East Ayrshire, taken over by Barr Environmental in May 2007. It was said to have suffered from a "persistent offensive odour".

Barr Environmental's director, Bill Weir, said: "We have made management changes and invested £500,000 in improvements with the aim of winning a positive assessment from Sepa for 2008."

Among other repeat offenders last year were the Ineos oil refinery at Grangemouth, ScottishPower's Longannet power station in Fife, Argent Energy's new biodiesel plant near Motherwell, and the Marshall chicken plant run by Grampian Country Food Group at Coupar.

Ineos said it was "disappointed" to have failed due to an oil pollution incident in the Firth of Forth caused by heavy rain. "We are working closely with Sepa on improvements to further reduce the likelihood of a similar event," said a company spokesman.

ScottishPower's unsatisfactory performance was caused by the continued illegal burning of sewage sludge pellets at Longannet. "This course of action represents the best practicable environmental option," argued a company spokesman.

Argent Energy's chief executive, Andy Hunter, blamed "teething problems" at its biodiesel plant - the first of its kind in Scotland. The company and Sepa were both on a "learning curve", he said.

One of the more embarrassing failures in 2007 occurred at the Blue Circle cement works run by French firm Lafarge, near Dunbar in East Lothian. The company is in partnership with the environmental organisation WWF.

According to Sepa, air pollution limits had been frequently breached. Works manager David Chrystall insisted these were now being dealt with as part of a £22m investment in pollution control equipment.

Dr Richard Dixon, director of WWF Scotland, was upset by Lafarge's poor performance. "We will be taking up these issues," he said.