Biofer-rem remediation technology involves the application of iron microparticles and easily fermentable substrates into the contaminated geological environment. This creates favourable thermodynamic conditions for (1) both abiotic and biological reduction of chlorinated ethenes and (2) the formation of reactive FeSₓ-based minerals, which also facilitate abiotic contaminant degradation. This technology is especially suitable for sulphate-rich sites. It was developed with financial support from TAČR (project TH01030851 "BIOGEOCHEM") and tested through a long-term pilot-scale trial. The project resulted in a validated technology and a functional prototype of the remediation product.