In the event that contaminants have seeped into the groundwater, additional treatment may be necessary. Hazardous wastes can generally be excavated without exposing people near the site to contamination. Wastes can be removed for further treatment or disposal at an approved landfill. Excavation uses common construction equipment and is a widely used and accepted method of dealing with hazardous waste. Excavation is also relatively inexpensive compared to other, more complicated treatment technologies.
Excavation is very effective in removing contamination and is commonly used at remediation sites.
There are no strict limits on the types of wastes that can be excavated and removed. Concern for worker health and safety, however, may prevent excavation of explosive, reactive, or highly toxic waste material. Incineration involves burning hazardous wastes to destroy such organic compounds as dioxins and PCBs. Incinerators can handle many forms of waste, including contaminated soils, sludges, solids, and liquids. Incineration is not effective in treating inorganic substances such as hydrochloric acid, salts, and metals.