Calcium Polysulfide can be injected directly into and under existing Coal Ash storage impoundments, Engineered Landfills and contaminated Ground Water supplies  providing immediate reduction of toxic materials and/or immediate treatment of contaminated Ground Water supplies.  This method limits surface disruption, avoids movement of hazardous waste, is economically feasible and provides immediate, testable results of successful remediation. Capping in place, landfilling of hazardous materials and drying out of Coal Ash impoundments do not actively address water contamination caused by toxic materials.