Hungry bugs clean up housing site

Contractors are working on site to clean up Rochester Riverside

Developers on a brownfield site where 2,000 homes are to be built have begun cleaning up the ground with the help of billions of microscopic bugs.

Industrial, maritime and commercial use since the early 19th Century has left Rochester Riverside contaminated with chemicals such as oil and creosote.

It would take decades for the soil to become safe if left untreated.

But bioremediation, in which natural bacteria in the ground is stimulated to speed up the process, takes 16 weeks.

The soil is first excavated and collected into huge mounds known as biopiles.

"We are adding nutrients and air to give the bacteria a balanced diet to stimulate the bacteria in the soil to degrade the contamination," said Graham Holton of site treatment firm Biogenie.

"It is a natural process where we take advantage of the bacteria already in the ground."

The method is one of several new technologies being used to clean up brownfield sites along the Thames Gateway development area.

"One of the main benefits is that we don't have to take any contaminated material off site," said Sarah Beck, project manager of 74-acre Rochester Riverside.

"It means we can save lorry movements through the Medway towns, which is of environmental benefit."