Permanent bin for temporary storage of hazardous materials

Claim 1

A storage bin for temporary storage of hazardous, non-volatile substances comprising: an excavation basin having an elevated periphery and a surface which slopes from said periphery along a collection path; a water-impervious liner for said basin comprising a water-impervious film; a water-impermeable covering for said liner comprising a monolithic layer of hardened cementitious material; a perimeter wall above and inside the rim of said water-impervious covering; said perimeter wall having a crest, an annular sloping outer surface and an annular sloping inner surface; a liquid-impervious coating over said annular sloping inner surface and over a continguous annular margin of the said water-impermeable covering; a monitoring drain comprising a collector conduit along the central region of said excavation basin beneath the said water-impermeable covering and above the said film; a collection sump located outside said perimeter wall; said collector conduit communicating with said collecting sump; said excavation basin being above the high water table level of the region.