Remediation of Contaminated Land

Chelmer believe that remediation of contaminated land doesn’t have to prevent the development of a site, rather it can unlock hidden potential. Sites once considered condemned or financially unsuitable, can now be quickly and economically transformed for redevelopment.

A scheme of remediation will depend heavily on the sites history and the quality of site investigation works undertaken at the site. Various remediation techniques can be utilised, individually or collectively, to achieve the ultimate end goal of a site suitable for its prosed end use. These technologies can help retain soils on-site, thus reducing the site to export off-site and incur haulage and landfill charges, or they can assist in reducing hazardous soils to a less onerous stable-non reactive or even inert classification, again reducing the cost of export off-site. Below is a brief summary of a few of the possible remediation options;

Bioremediation involves the enhancement of natural degradation of contamination by controlling features such as the moisture, temperature, oxygen and pH levels of the material, as well as by adding specific nutrients to speed up the bacterial process. This process has proven particularly effective with hydrocarbon contaminants such as petrol and diesel range organics, polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). This process often involves the excavation and stockpiling of soils, but can be utilised in-situ through boreholes or trenches.

Current UK asbestos guidance is very complex, thus Chelmer can assist through investigations, assessment and management of asbestos contaminated soils. Asbestos contaminated soils can be handpicked, sorted and managed to reduce risks to human health and reduce the costs of off-site disposal.

Soil washing is a technique where soils of different particle sizes are separated by high pressure washing before treatment, resulting in only relatively small amounts of heavily contaminated fine grained material requiring off-site removal.

Soil Stabilisation is ustilised to reduce the permeability and/or increased the strength of the soil and involves the introduction of cementitious or specially formulated solutions directly into the ground, or into stockpiled soils. For contaminated soils, a physical bond is created which immobilises contaminants, lowering the permeability of the treated soils and reducing or even preventing leaching.

A Permeable Reactive Barrier (PRB) can be installed below ground to remediate contaminated groundwater. These are designed to absorb or adsorb contamination from the groundwater or to convert harmful contamination to harmless by-products. They can be installed as a wall to intercept a migrating plume of contaminated groundwater, or funneled to a gate containing the reactive media – ‘funnel and gate’ method. These are often a cost effective solution to groundwater treatment, with minimal visual impacts and long term effectiveness.

Water treatment systems can be designed and built to treat contaminated groundwater or surface water, which are site specific to each site depending on the type of contamination encountered and the sites specific requirements.

Chelmer have a wide range of experiences and knowledge and are capable of guiding the client through each required stage, both in planning and undertaking the remediation schemes, to assit the client with achieving their time and financial targets.