Waste soil may be classed as either hazardous or non-hazardous as governed by waste legislation. The producer is required to undertake a waste characterisation exercise prior to disposal. In some cases, waste soil may be disposed of as inert waste. However this needs to be demonstrated through assessment and appropriate analysis. The use of Waste Acceptance Criteria (WAC) testing alone cannot classify waste. As detailed in the Environment Agency’s Technical Guidance WM3 Ver.1 (2015) entitled ‘Guidance on the Classification and Assessment of Waste’, waste classification is a two stage process. Wastes are presented in the List of Wastes Directory (LOWD, 2014/955/EU) and grouped according to generic industry, process or waste types. Wastes within the LoWD are either Hazardous or NonHazardous. Some wastes are Hazardous without further assessment (absolute entries) or are ‘mirror’ entries that require further assessment as to hazardous properties in order to determine whether the waste is hazardous or nonhazardous. Waste soil has mirror entries on the LoWD and, as such, the first phase of the waste classification process is to determine if the waste is Hazardous or not i.e. a Hazard Assessment and to identify the Hazard Properties of the waste. Certain contaminants (e.g. asbestos, diesel) have prescribed concentration thresholds that, if breached, will automatically render the material as Hazardous waste. Therefore, the concentrations of plausible contaminants within the soil should be determined. This is carried out by routine analysis at a MCerts lab (sometimes called acid extractable, air dried results). Results of this assessment should help to determine the likely fate of the soil (reuse elsewhere or disposal) and whether or not the soil is Hazardous or NonHazardous.
Once the soil has been assessed as either Hazardous or Non-Hazardous, then the results of the WAC test can be used to assess the correct disposal route. Given that current landfill tax for non-Inert waste is £88.95 per tonne (compared to £2.80 for Inert waste), plus the cost of transporting to, and disposal at, a hazardous waste landfill, significant savings can be produced if waste can be classified for disposal at an Inert waste facility. Stansted Environmental Services Limited can provide advice on waste characterisation and disposal of soils from site.