Changing nature of remediation

With contaminated soil streams now attracting expensive hazardous waste disposal rates at landfill, alternatives to dig and dump have become a necessity. Changes in landfill tariffs have encouraged companies to develop new ways of treating contaminated soil.

An example of this are the off site treatment centres established by Churngold Remediation. Branded as a soil surgery, these installations receive contaminated soil and treat it prior to disposal. Contaminated soil is removed from a developer’s site to the treatment centre where – once certain pre-agreed characterisation criteria have been satisfied – Churngold takes ownership of the contaminated soil, absolving the developer of liability for the soil thereby bringing the site back into use as quickly as the development dictates.

“A vast range of soils can be accepted at our soil surgeries,” says Craig Sillars, managing director of Churngold. “Transfer of ownership and liability for clean up of unremediated soil will appeal to landowners, contractors and environmental consultants.”

At the end of the 1980s, bioremediation was seen as the new wonder solution. By 1991 the honeymoon was over as the industry realised that success in a jar didn’t necessarily equate with success on site. However into the new millennium, the market has rallied, steadied and matured.

Remediation is now widely used, but the nature of the solutions is changing. Some believe the future lies with in-situ solutions such as chemical oxidisation or chemox. Companies such as QDS Environmental have long been using powerful oxidants such as Fenton’s reagent and permanganate as a key part of the remediation solution on large scale projects.

“On-site treatment-based remediation is now finding widespread use in UK as the previous low cost default option of dig and dump is seen to be less acceptable and increasingly costly,” says Clive Boyle, director at QDS.

With the majority of projects being development or disinvestment driven, speed and certainty of outcome are critical factors to those commissioning remediation work. The range of in-situ chemical oxidation techniques can deliver remediation objectives on appropriate sites in weeks rather than months.

New technologies mean that many efficient solutions now exist. They do not require specialist on-site chemical equipment, and work rapidly. Products such as Regenox supply an in-situ chemical oxidation product in a bucket – and no special equipment is required. In some domestic uses, simple gardening techniques have been all that were needed to transfer the product through the soil.

Regenox is one of a new generation of chemox products that have the oxidising power of a Fenton’s agent but can be handled as easily as an oxygen release product (ORP). Industry stalwarts such as Hydrock, Remedex and Belfor can testify to the success of these on a wide range of contaminants.