THE SUBJECT CONSENT DECREE, WHICH WAS ORIGINALLY FILED ON FEB 12, 1980, WAS THE CULMINATION OF EXTENSIVE LITIGATION REGARDING VIOLATIONS OF THE NPDES PERMIT FOR EFFLUENTS FROM THE HOMESTAKE GOLD MINE IN LEAD, SOUTH DAKOTA. IT REQUIRED HOMESTAKE TO COMPLETE AND PLACE IN OPERATION A SAND FILTRA- TION SYSTEM FOR TITAL SUSPENDED SOLIDS BY SEP. 1, 1979, AND A TREATMENT SYSTEM FOR HEAVY METALS AND TOTAL CYANIDE BY SEP. 1, 1980. THE CONSENT DECREE (CD) IMPLICITLY RECOGNIZED HOWEVER, THAT THE PERMIT LIMITS FOR HEAVY METALS AND CYANIDE WERE TECHNOLOGY-FORCING AND THAT HOMESTAKE WAS INVESTIGATING A NUMBER OF CONVENTIONAL AND UNTRIED TREATMENT SYSTEMS. THE DECREE, THEREFORE, INCLUDED PROVISION FOR EXTENSION OF THE DATE STIPULATED FOR DECISION ON A PARTICULAR TREATMENT SYSTEM (MARCH 1, 1980), AND FOR SUBSEQUENT REVIEW OF THE AFFECTED WATER QUALITY AND NPDES STANDARDS BY SOUTH DAKOTA AND EPA, AFTER THE ACTUAL PERFORMANCE OF THE SYSTEM CHOSEN. ON JULY 14, 1980, THE ENFORCEMENT DIRECTOR OF REGION VIII APPROVED AN EXTENSION OF THE DECISION DATE TO JULY 1, 1981. THIS EXTENSION WAS BASED UPON PROGRESS BY HOMESTAKE TOWARDS A CHEMICAL AND BIOLOGICAL TREATMENT SYSTEM, AND UPON ASSURANCES THAT HOMESTAKE WOULD MAKE EFFORTS IN GOOD FAITH TO MEET THE ORIGINAL SCHEDULE WITH THAT SYSTEM. SUBSEQUENTLY, HOMESTAKE ACHIEVED A BREAKTHROUGH IN A PURELY BIOLOGICAL TREATMENT SYSTEM WHICH REGION VIII AND HQ TECH. STAFF FEEL WILL BE BOTH MORE EFFECTIVE