Processed resistivity survey lines. Lines 4 and 5 with notes from trial pit data. - .PDF file.
The Environment Agency (EA) has unveiled its latest weapon to tackle serious waste crime without the need to perform expensive dig operations.
The agency claims its new scanner will help speed up the prosecution process for illegal polluters and save tax payers thousands of pounds each year.
Steve Openshaw, chief executive of Bentham Geophysical Consulting and contractor of the device, said that the technology could provide a more effective tool for distinguishing between different materials below the surface compared to current bore-hole drilling methods.
‘This is an improvement on traditional techniques,’ he added. ‘For the EA’s application we’ve used a large number of electrodes to collect more detailed data… If you know roughly where an illegal landfill site is, you will be able to detect it with this device.’
Bentham’s scanner uses a technique known as resistive tomography, which collects data from up to 256 electrodes placed at regular intervals in the ground. An electrical current is passed between the electrodes to measure the resistivity in the soil, rock and surrounding material.
Data from the electrodes is then sent to an on-site computer to reveal static images of the subsurface environment. These images can show the depth and shape of most potential landfill zones, however, problems still remain in identifying materials with similar properties.
‘It’s not uncommon to try to detect waste sands that have been put into a sandstone quarry,’ said Openshaw. ‘The waste sands have a very similar chemical property to the in situ sandstone. So at that point there’s no contrast to measure. Used alongside other techniques however, this is something that can be overcome.’
The technology is expected to add to the Agency’s existing techniques, which include forensics, handwriting analysis and smart water tracking – an invisible liquid that highlights waste items and contaminates anyone in contact with them.
Dr Paul Leinster, chief executive of the Environment Agency, said: ‘This is just one of the many state-of-the-art technologies that the Environment Agency uses to make sure that waste criminals are caught, prosecuted and made to pay to clean up the land they have polluted.
‘By dumping waste illegally, waste criminals avoid landfill charges and undercut legitimate waste businesses, but more importantly they put the environment and human health at risk. We are making sure that waste crime does not pay. We have set up specialist crime teams to catch criminals and confiscate the assets they’ve gained from crime.’
On its first use for the agency in October, the technology uncovered a large area of buried waste in the New Forest National Park. It is estimated that clean-up of the site will cost in the region of £500,000.
Since 2008 the EA’s crime team has closed 1,500 illegal waste sites, with fines for committing waste offences increasing since 2003, from £1.4m to more than £3m. The Agency hopes the new technology will help close around 800 illegal sites that are still in operation.