Historic Oil/Gas Drilling Waste Sump Siku C-55 appears to be eroding. The sump is partially (70 %) flooded. The substance of a drilling waste appearance was found in cracks on the remaining tip of the sump cap. The substance had distinct petroleum hydrocarbon smell. A sheen of distinct petroleum origin iridescence was noted on the surface water in this area. Electrical conductivity measurement had shown that it was significantly higher in the standing water above the sump than in other surface water bodies in the area. This evidence is sufficient to conclude that the historic drilling waste sump has lost containment and is continually releasing drilling waste into the open environment.