SYNOPSIS OF THE CASE MARTIN MARIETTA (COMPANY) OPERATES A PRIMARY ALUMINUM REDUCTION PLANT NEAR GOLDENDALE, WASHINGTON. (ATTACHMENT 1) IN MARCH OF 1978, MARTIN MARIETTA APPLIED FOR A PSD PER- MIT TO MODIFY THE GOLDENDALE FACILITY. THE PLANNED MODIFI- CATION INCLUDED THE ADDITION OF A NEW POTLINE AND VARIOUS TECHNICAL CHANGES TO THEIR EXISTING POTLINES TO REFLECT THE NEW SUMITOMO DESIGN. THE NET RESULT WAS TO BE ADDITIONAL PRODUCTION OF 65,000 T/YR OF ALUMINUM AND A REDUCTION IN EMISSIONS OF ALL POLLUTANTS. THE SUMITOMO DESIGN WAS EX- PECTED TO RESULT IN A LOWER EMISSION RATE FROM THE CELLS, SMOOTHER OPERATION AND A MAJOR INCREASE IN THE CAPTURE EFFI- CIENCY, THAT IS, THE PERCENTAGE OF EMISSIONS THAT GO TO THE PRIMARY CONTROL SYSTEM. ON AUGUST 30, 1978, EPA GRANTED THE COMPANY A PSD PERMIT FOR AN ADDITIONAL POTLINE UTILIZING THE NEW SUMITOMO TECHNOLOGY. (ATTACHMENT 2) THE EMISSION LIMITATIONS IN THE PSD PERMIT WERE BASED ON THE EXPECTED EMISSION CONTROL PRESENTED BY MARTIN MARI- ETTA IN THE PSD PERMIT APPLICATION. HOWEVER, EPA USED A MORE CONSERVATIVE EMISSIONS CONTROL OUTCOME TO DEVELOP THE EMISSION LIMITATIONS RATHER THAN RELY EXCLUSIVELY ON THE COMPANY'S PROJECTED EMISSIONS WHICH WERE LOWER THAN EPA'S AND APPEARED TOO OPTIMISTIC. THE PSD PERMIT REQUIRES THE COMPANY TO DEMONSTRATE COMPLIANCE WITH ITS PERMIT EMISSION LIMITS WITHIN 180 DAYS AFTER STARTUP (