Mesocosm Experiments at a Tunnelling Construction Site for Assessing Re-Use of Spoil Material as a By-Product

Mechanized excavation of tunnels with Earth Pressure Balance-Tunnel Boring Machines requires the use foaming agents. The latter contain anionic surfactant sodium lauryl ether sulphate (SLES) as main compound. re-use a by-product excavated soil containing agents (spoil material) can pose risk for and particularly aquatic ecosystems if they are close to spoil material final destination site. This work reports chemical results (SLES residual concentrations) ecotoxicological effects (battery five tests) 28 day-mesocosm studies performed at tunnelling construction mesocosms were set up two different lithologies, which contained four agent products highest amounts used excavation. decrease in SLES concentrations tests its water extract (elutriate) times (0, 7, 14, d). Elutriates prepared order simulate possible leaching from water. showed over time responses depending not only on initial amount each product, but also lithology organism tested (aquatic or terrestrial). study how site-specific evaluations ensure safe management material, making avoiding production waste.