Soil contamination is caused by the presence of man-made chemicals or harmful fibres in the natural soil environment. It is often caused by some form of industrial activity, the improper disposal of waste (fly-tipping) or remnants of waste building materials (including asbestos) from the lands original use.
The biggest concern associated with soil contamination is the harm it can cause to human health. There are significant health risks involved with direct contact with contaminated soil, and even secondary contamination of water supplies.
Soil remediation is the reduction of contaminant concentrations within the soil. The aim of soil remediation, in the majority of cases, is to reduce contaminants to levels which are ‘suitable for use’, essentially resulting in the use of the affected site without environmental risks or danger to health.
Types of soil remediation:
ION Environmental offers 5 types of soil remediation, the use of which is dependent case-by-case and will depend on several factors, including the amount of asbestos found and the planned use of the area following remediation. Remediation options we offer include:
Leave in situ:
This option is most common when asbestos is present but there is little probability of the soil being disturbed and it may be appropriate to leave the asbestos buried and undisturbed. In this instance we use marker membrane and cover systems including capping, and ensure accurate survey and asbestos locations are added to the health and safety file informing all follow-on trades that asbestos is present.
Our on-site treatment consists of a detailed six-part process (identification > segregation > planning > methodologies > air monitoring and waste) to ensure thorough and compliant removal of asbestos contaminated materials from site. Asbestos cleared from the soil leaves the site safely under a consignment note, carried by licenced waste carrier only.
Once treated and all visible asbestos contaminated materials are removed, the soil can be reused (subject to the MMP agreed by the regulators), but with certain restrictions:
- The reused soil will need to be capped.
- The location will need to be identified in the health and safety file for follow on works.
- Consideration needs to be made as to the future use of the proposed reuse location.
Here, asbestos contaminated soil is collected and sent to a facility where it is ‘cleaned’, during which asbestos and any other contaminants are removed from the soil, ensuring the soil is clean and fit for re-use on site. This approach is more costly, but it has environmental benefits as it stops the contaminated soil from going to landfill and the ‘cleaned’ soil is available for re-use.
This is the safest method of remediation. The asbestos contaminated materials and soils are removed from site by a licenced carrier and sent to land fill, ensuring there are no problems with follow on works. However, there is an environmental impact of sending the soil to land fill and the additional cost of buying more soil to replace that which has been disposed of.