Under The Landfill Directive, in order to dispose of any material at landfill there is a requirement to classify the waste as Hazardous, Non-Hazardous or Inert. In order to comply with this requirement you may need to undertake Waste Acceptance Criteria (WAC) analysis in line with British Standard European Norm (BS EN) 12457 part 1, part 2 or part 3.

ALS Laboratories supported the consultation in the production of the new guidance alongside other key organisations involved in the Waste Management Industry. The new guidance alongside the EA’s Hazardous Waste Technical Guidance WM3 allows waste to be disposed of to landfill to be characterised to ensure that waste management operators fully understand the nature of the waste they will be receiving.

The guidance includes: Classification and Characterisation requirements for waste, actions that could be undertaken in the event of failing a test criterion and sampling schedules and testing requirements. It is changes to Appendix 3 (Key Laboratory Process Steps) which we at ALS Laboratories l believe would be of specific interest to our clients, such as:

• Waste Producers
• Waste Managers
• Landfill Operators

Previously the requirement was for the leaching of samples using method BS EN 12457-3 which involves a 2 stage leaching process (a moisture corrected 2:1 liquid to solid ratio leaching step for 6 hours followed by a moisture corrected 8:1 liquid to solid ratio leaching step on the remaining material for 18 hours).

The new requirement for method BS EN 12457-2 allows a single stage leaching process (moisture corrected 10:1 liquid to solid ratio leaching step for 24 hours).  This will mean that by selecting  the  BS EN 12457-2 method, ALS Laboratories will be able to turnaround the analytical WAC reports quicker than the previous 2-stage leaching procedure outlined in BS EN 12457-3.

The BS EN 12457 WAC standards and each Part of the regulations is outlined below:

BS EN 12457 Part 1

BS EN12457-1 is a single stage leaching process at a liquid: solid ratio of 2:1. Analytical data is reported as mg/kg dry weight, calculated by using the dry ratio. The breadth of analysis is not specified under BS EN 12457-1 can be tailored to site specific requirements.

BS EN 12457 Part 2

BS EN 12457-2 is a single stage leaching process at a liquid: solid ratio of 10:1. Analytical data is reported as mg/kg dry weight, calculated by using the dry ratio. Similarly to the National Rivers Authority (NRA) 10:1 leaching method, BS EN 12457-2 does not have a specific suite of analysis and can be tailored to site specific requirements.

BS EN 12457 Part 3

BS EN 12457-3 utilises a two stage leaching process at liquid: solid ratios of 2:1 and 8:1, the combined results from which are calculated to provide analytical data reported as mg/kg dry weight at 10:1, moisture content corrected. The suite of analysis under BS EN 12457-3 is descriptive to a minimum point, however, additional analysis can be undertaken to address any site specific requirements.

The UK Environment Agency's “Waste Sampling and Testing for Disposal to Landfill” states that BS EN 12457-2 should be used for all waste types, unless rapid leaching of contaminants is expected, when BS EN 12457 – 1 is considered to be appropriate.