Point, click and evaluate site soil contaminants - New technology

An Australian company is bringing a handheld soil scanner to North America which can detect total petroleum hydrocarbon contamination at levels as low as 68 ppm in 20 seconds. The RemScan was developed in part by the Australian national technology agency, the Commonwealth Science and Industrial Research Organisation (CSIRO) and industry and waste remediation specialist Ziltek.

"We started working on it around 2010 and by 2014 we had a proven model and we started selling all around the world," said Dr. Richard Stewart, managing director of Ziltek. "Right now we're dealing with the big oil companies directly through their head offices but at some point we're looking to offer it at retail through our North American partner Tersus Environmental."

The device is about the size of a large hair dryer, weighs about three kilograms and is hand carried on-site to test locations. It can process about 120 samples an hour and there's no soil extraction or physical sampling required. It has rechargeable batteries which run eight hours and connects wirelessly to a proprietary PDA (personal digital assistant) which is mounted on the back of the device but can be easily removed to review the data.

How does it work?

"It uses an infrared signal which is then directed at the location, they pull the trigger and within about 20 seconds they have a result," said Dr. Stewart. "The advantage, of course, is that you can get instant results rather than having to pack jars with samples and send them off to a lab which takes another week or more to get results. In fact, the more remote and isolated the location you're working at, the more value the RemScan offers."

The infrared pulse detects the unique signatures of hydrocarbons and the onboard software separates them out and provides levels. The device can measure as low as 68 ppm which is almost as sensitive as the laboratory benchmark of 55 ppm, explained Stewart. The red flag levels for hydrocarbon soil contamination are about 1,000 ppm for residential and 10,000 ppm for industrial, he said.

The readings are accurate within 10 per cent of a laboratory test. The only downside is that the device is sensitive to moisture and at water levels above five per cent the soil must be dried before testing for accuracy. The tolerances and performance have been certified by the independent agency Batelle in the U.S. using their Environmental Technology Verification (ETV) program standards.

The device can be used to map contamination levels across a site and locate the epicentre of a spill or leak location in the event of contemplated new construction or in the field to track live leaks in storage facilities or pipelines.

Where does it function most effectively?

It's particularly effective in an emergency response, Stewart said, because of the instant read out and the ability to get multiple readings in a short time. For example, an Australian client used it to track a diesel leak at a storage facility, sampling more than 200 times a day. This meant the evaluation phase was wrapped in four days. It was also used after the event to check the effectiveness of the subsequent remediation.

In another case, it was used to survey the site of an old transformer which had been removed for replacement. Oil was obvious on the ground after removal so the location was excavated and the RemScan confirmed the contamination had been removed.

How much does it cost?

The RemScan isn't cheap at about US$68,000 but for big oil companies looking for leaks along pipelines or hydrocarbon contamination on sites it will pay for itself within a couple of years, he said. "There are no moving parts, no consumables and we've not yet had one come back for repair," he said. "Buyers can also get a package which provided all software upgrades and if they have a software problem we can send them updated software either to their mobile or to a Dropbox."

He said the price is comparable to a similar device, the S1 Titan Handheld XRF analyzer made by Bruker Corp which measures metal contamination in the soil which was also priced initially at US$68,000 but has since dropped to US$30,000 to US$40,000. He said the next tier they want to address is the construction equipment rental market where they think it will retail for about $1,200 a week with options for daily and monthly leasing.