DEF IS SUBSIDARY OF ASARCO, INC AND OPERATES A METAL REFINING PLNT IN N.J. ONE PROD IS MAGNESIUM ANODES. A BAG- HOUSE CNTRLS EMISSIONS FR MAGNESIUM KETTLES THAT PROD ANODES BAGHOUSE IS REQ BY NJDEP. ON 11-2-83, AN INSP OF DEF REVEALED THAT DEF WAS USING IMPORTED, CONTAMINATED MAGNESIUM SCRAP WHICH CLOGGED BAGHOUSE. AS A RESULT, CAPTURE SYSTEM AND BAGHOUSE WERE INEFFECTIVE AND FUMES EXITED DIRECTLY. AFTER 11/25/83 MTG W/EPA, DEF SAID IT WOULD QUIT USING IMPORTED SCRAP BUT WOULD USE SCRAP IN STOCK AND IN TRANSIT. AFTER MTG W/EPA ON 02/27/84, DEF SAID IT WOULD NOT USEANY IMPORTED SCRAP OR USE KETTLES UNTIL NEW BAGS INSTALLED, CLEANER SCRAP IS OBTAINED, AND THE OPERATION CAN RUN IN ACCORD W/ CERT TO OPERATE AND ALL APPLIC REGS.