Under the Land Disposal Restrictions (LDR) program of the Resource Conservation and Recovery Act (RCRA), EPA is extending the current national capacity variance for spent potliners from primary aluminum production (Hazardous Waste Number K088) for six (6) months. Thus, K088 wastes do not have to be treated to meet LDR treatment standards until July 8, 1997, six months from the current treatment standard effective date of January 8, 1997. EPA is extending the national capacity variance due to unanticipated performance problems by the treatment technology which provides most of the available treatment capacity for these wastes. As a result, the Agency does not believe that sufficient treatment capacity which minimizes short and long-term threats to human health and the environment posed by land disposal of the potliners is presently available. The length of the extension of the national capacity variance is based on EPA's best current estimate of the time it will take to modify, evaluate, and correct the current deficiencies in treatment performance.