Thames Water, Britain's largest water and wastewater company, has become the first British utility to be re-accredited with the Carbon Trust Standard.

In 2007/2008 Thames Water became the first UK utility to receive the Carbon Trust Standard. Two years on, the company has reduced carbon emissions by further 4.9 per cent (39,000 tonnes) - equivalent to taking 15,000 cars off the road. Based on a rigorous, independent assessment, the Carbon Trust Standard is awarded to organisations for their sustained commitment to tackle climate change by measuring, managing and actively reducing their carbon emissions.

To achieve the Carbon Trust Standard, organisations must as a first step measure their direct carbon footprint - for example, on-site fuel and electricity use, prove to have good carbon management practices in place and demonstrate genuine reductions in their emissions over a three-year period.

Upon initial certification organisations also commit to continually reduce both their direct and indirect - for example, business travel - carbon emissions over the next two years before reassessment.

Martin Baggs, Thames Water's Chief Executive, said:

"For a company the size of ours to reduce its greenhouse emissions nearly 5 per cent in almost three years requires a great team effort. From generating £15m a year in renewable energy from sewage to making sure we turn off lights when we leave the room, everyone across our business plays a part.

"Receiving re-certification with the Carbon Trust Standard is proof we are heading in the right direction - but there is still a way to go yet before we hit our goal of cutting our greenhouse emissions by 20 per cent on 1990 levels by 2015."

Thames Water supplies water to 8.7 million people and takes away and treats 13.8 million people's sewage across London and Thames Valley, . Energy-intensive water and sewage transport and treatment results in carbon emissions  ofabout 750,000 tonnes a year  for the company.

Thames said the reduction in emissions has been achieved by focusing on reducing energy consumption, improving pumping efficiency and generating more renewable power at sewage works across the region.

Harry Morrison, General Manager of the Carbon Trust Standard, commented:

"We congratulate Thames Water on being the first in their industry, and only the second company in the UK, to attain recertification with the Carbon Trust Standard. It's great to see them continuing to lead the way in the utility industry when it comes to carbon management best practices.

"Achieving the Carbon Trust Standard allows Thames Water to talk with integrity about their ongoing commitment to consistently measure, manage and reduce carbon emissions across their operations. It is a true testament to the company's genuine efforts to reduce their impact on climate change."