The inter-agency group also identified the need for independent experts to draw up an expert plan for the remediation of the tailings pond and other areas, particularly in view of the fact that these sites contain toxic material, including lead, cadmium, arsenic, mercury and other substances. One of the sites leaks leachate into local streams. Another site is highly toxic, containing residues from mining, with which no human or animals should be in contact. Clearly expert advice was required.