The Mining Remediation Authority used ochre from its Deerplay mine water treatment scheme to bind lead‑contaminated soil at a 5,200‑square‑metre former lead works site in Chester.
The brownfield, once a lead smelting plant and later a municipal car park, has sat idle since the 1990s because of soil that still contains lead and asbestos fragments, stalling any redevelopment plans.
Ochre, a by‑product of iron‑rich mine water treatment, reacts with soil particles to lock heavy metals in place, preventing them from leaching into groundwater.
James White, Mining Remediation Authority project lead, said the move demonstrates circular‑economy principles by turning waste into a stabilising agent.
The remediation work will pave the way for a 126‑apartment residential block, slated to break ground in late 2026 and complete by 2027.