EPA is considering establishing an alternative treatment standard for high-concentration mercury wastes. The Agency is reviewing Republic Services’ petition for a Land Disposal Restrictions (LDR) treatment variance that would allow it to stabilize elemental mercury extracted from high-level mercury-containing wastes through a process of conversion to mercuric sulfide followed by double encapsulation and monofill disposal. If the petition is approved, EPA will develop a rulemaking to establish an alternative treatment standard for the land disposal of high-concentration mercury wastes after public notice and comment.