Abstract: A method of filling and sealing a hole extending a great distance into the earth and containing liquid contaminants, the steps comprising forming a cement slurry, continuously pumping the cement slurry through a conduit extending to the bottom of the hole, continuously forcing the cement slurry from the open end of the conduit while the conduit is being withdrawn from the hole, continuously monitoring the level of the cement slurry within the hole, controlling the rate of withdrawal of the conduit so as to maintain the open end thereof below the level of the cement slurry being deposited within the hole, and removing the contaminants from the opening of the hole as they are displaced by the cement slurry being deposited therein. Also, apparatus suitable for conducting the above method.