06/30/90: SYNOPSIS OF CASE: STRUCTURAL METALS IS A STEEL MANUFACTURING PROCESS, SMI GENERATES LARGE AMOUNTS OF PARTICULATE EMISSIONS FROM ITS ELECTRIC ARE FURNACES, WHICH ARE COLLECTED IN A DRY SCRUBBING SYSTEM. THE RESULTING ELECTRIC ARC FURNACE BAGHOUSE DUST (EPA HAZARDOUS WASTE NUMBER KO61--HEREINAFTER, K061 ), IS THE HAZARDOUS WASTE OF CONCERN IN THIS CASE. ON AUGUST 17, 1988, EPA PROMULGATE LAND DISPOSAL PROHIBITIONS AND TREATMENT STANDARDS FOR SO- CALLED FIRST THIRD WASTES, INCLUDING SUBCATEGORIES THE LOW ZINC SUBCATEGORY (GREATER THAN OR EQUAL TO 15% TOTAL ZINC AND THE HIGH ZINC SUBCATEGORY. SMI GENERATES HAIGH ZINC SUB -CATEGORY KO61 WASTE. SMI LAND DISPOSED OF SOME OF ITS HIGH ZINC SUBCATEGORY KO61 WASTE WITHOUT TREATING IT AS REQUIRED BY THE LAND DISPOSAL RESTRICTIONS.