SCIENTISTS from around the world have been arriving in Trafford to celebrate a rather unusual birthday.

Sewage treatment is 100 years old this month - and it all started in Davyhulme.

"It might not look like much - "but this brown goo revolutionised cities around the world, starting with Manchester," said Phil Sweeney, United Utilities area business manager, In 1914, two Manchester Corporation employees based at Davyhulme sewage works invented a new process called 'activated sludge'.

It harnassed the power of micro-organisms and meant that waste from millions of people could be treated in a relatively small space - which allowed cities to grow and develop on scale never seen before.

Every time we flush the loo is flushed or the dishwasher used, it can be taken for granted that the dirty water will be taken away and dealt with safely. But it wasn't always that simple.

Davyhulme works opened in 1894 to cope with all the waste from the growing city.

Parishes on the outskirts of Manchester were now queuing up to take advantage of the sanitation and, in just a generation from 1885 to 1909, the city of Manchester tripled in size.

Davyhulme treatment works was going to have to move up a gear if it was to stop rivers becoming seriously polluted.

The new process, discovered by Edward Ardern and William T Lockett, was published in a scientific paper in April 1914 and sewage treatment plants around the world use the system to this day.

United Utilities welcomed experts to the Davyhulme treatment plant as part of an international conference at the Point, Lancashire County Cricket Club.

The boffins took a tour of the plant to find out how it all started and see the scale of what's been achieved since.

Phil explained: "We're celebrating the innovation that has continued at Davyhulme over the past 100 years.

“Manchester's Victorian city fathers were excellent at joined-up thinking – they had the political will and the know-how to solve a sanitation crisis.

“These days United Utilities is working closely with the Environment Agency to ensure Davyhulme continues to serve the needs of the city for another 100 years and more.”

The new sludge recycling centre at Davyhulme is largest of its kind in the world. It takes a problem waste stream, the sludge left over after sewage treatment, and converts it into renewable electricity and a high quality fertiliser for farmers.

Later this spring a £200million modernisation project gets under way at the plant. By 2018 the oldest parts of the site, some dating back to the 1930s, will be replaced with the latest energy-efficient equipment.

Phil said: “It’s just the latest stage in the plant’s evolution. It will mean the waste is treated to the highest standards ever, using much less energy. That’s good news for the Manchester Ship Canal and good news for our customers’ bills.”