MINE SAFETY APPLIANCES COMPANY (MSA) IS THE OWNER & OPER- ATOR OF AN EXISTING HAZARDOUS WASTE MANAGEMENT FACILITY LO- CATED ON MARS ROAD IN EVANS CITY, PA. MSA SUBMITTED TO EPA A TIMELY NOTIFICATION OF HAZARDOUS WASTE ACTIVITY FOR THE FA- CILITY, PURSUANT TO RCRA SEC 3010(A), 42 USC SEC 6930(A), & A TIMELY PART A PERMIT APPLICATION FOR THE FACILITY, PURSU- ANT TO 40 CFR SEC 270.10 & 270.70 AND THEREBY OBTAINED IN- TERIM STATUS UNDER RCRA SEC 3005(E), 42 USC SEC 6925(E), FOR SEVERAL HAZARDOUS WASTE STORAGE & TREATMENT UNITS AT THE FA- CILITY. MSA FAILED TO IDENTIFY 2 HAZARDOUS WASTE MANAGEMENT UNITS IN ITS PART A PERMIT APPLICATION: 1) A SURFACE IMPOUNDMENT USED FOR THE TREATMENT AND/OR STORAGE OF ACID WASTES & SEW- AGE GENERATED AT THE MSA FACILITY (ACID POND); AND 2) A 2ND SURFACE IMPOUNDMENT USED FOR TREATMENT AND/OR STORAGE OF CAUSTIC WASTES GENERATED AT THE MSA FACILITY (CAUSTIC POND). AS A RESULT OF MSA'S FAILURE TO INCLUDE THESE UNITS ON ITS PART A, THESE UNITS NEVER TECHNICALLY QUALIFIED FOR INTERIM STATUS. DESPITE ITS FAILURE TO OBTAIN INTERIM STATUS FOR THE A- BOVE DESCRIBED UNITS, MSA HAS CONTINUED TO TREAT AND/OR STORE HAZARDOUS WASTES IN THOSE UNITS SINCE 11/19/80, THE EFFECTIVE DATE OF EPA'S REGULATIONS IMPLEMENTING RCRA SUB- TITLE C, AND CONTINUES TO TREAT AND/OR STORE HAZARDOUS WASTES IN THOSE UNITS AT THE PRESENT TI