Constituent concentrations of leachates from standardised leaching tests using deionised water and seawater in contact with legacy waste materials collected from coastal areas of the UK between 2020 and 2024

Each waste sample comprised five sub-samples of approximately 500 g, collected from an approximately 5 - 10 m2 area of waste at the location within the site. Sub-samples were collected in plastic bags using a plastic trowel. In the lab, sub-samples were combined to form a composite, which was then mixed (coned and quartered) before sub-sampling for analysis. Sample preparation and analysis from that point forwards followed the methodology of a British Standard leaching test (British Standards Institution (BSI) (2002) BS EN 12457-2:2002 Characterisation of waste - leaching - compliance test for leaching of granular waste materials and sludges - Part 2: One part batch test at a liquid to solid ratio of 10 L / kg for materials with particle size below 4 mm (without or with size reduction) (British Standards Institution, London).
Analysis of leachates following 24 hours of end-over-end mixing of the waste sample with either deionised water or seawater was completed using the following equipment:

- A pre-calibrated Myron L 6P Ultrameter: Temperature, pH, Eh, Conductivity
- Agilent 5800 Series ICP-OES and / or Agilent 7700 Series ICP-MS: Metals concentrations
- Thermo Scientific Dionex Integrion Ion Chromatograph: Anions (sulphate and chloride)

Both total and filtered concentrations are reported for most constituents. In all cases filtering of leachate was through a 0.45 um cellulose nitrate filter (prior to acidification with 2% v/v concentrated nitric acid in the case of samples for metals analysis). Concentrations of constituents, reported in mg/kg, were converted from units of mg/L as detailed in BSI (2002).

Related datasets

List of legacy waste deposits (including historical landfill sites) across England and Wales, ranked by environmental risk to the coastal environment under future climate scenarios