On April 8, 1996, EPA published treatment standards (the ``Phase III'' final rule) for a number of hazardous wastes associated with the production of carbamate pesticides (``carbamate wastes'') (61 FR 15566, April 8, 1996). The treatment standards were expressed as levels of chemical constituents that had to be measured in treatment residues before land disposal. They became effective July 8, 1996. The Agency recently has become aware, however, of a serious analytic monitoring problem associated with the carbamate constituent treatment standards. Laboratory standards (chemicals used to calibrate laboratory instruments) do not exist for every carbamate constituent. Since commercial laboratories currently are unable to analyze all of the carbamate waste constituents, treatment facilities cannot certify that the LDR treatment standards have been achieved. Today's final rule revises the carbamate waste treatment standards for one year from the date of publication by allowing carbamate wastes to be treated either by any technology which achieves the constituent concentration levels promulgated in the Phase III rule, or by treatment technologies specified in this final rule as alternative treatment standards. This rule also suspends the requirement to treat carbamate waste constituents when they are expected to be present in ignitable, corrosive, reactive or toxic hazardous wastes as ``underlying hazardous constituents.'' The Agency believes that these temporary alternative treatment standards will assure that carbamate wastes are adequately treated prior to land disposal, while providing time for analytic chemical standards to be developed. At the end of the year EPA expects that laboratories will be able to perform the analyses necessary to measure compliance with treatment levels. At that time, therefore, the LDR treatment standards for carbamate wastes will revert to those originally promulgated in the Phase III rule.