<ARTICLE> 5 <CIK> 0000822818 <NAME> CLEAN HARBORS, INC. <MULTIPLIER> 1,000 <PERIOD-TYPE> YEAR <FISCAL-YEAR-END> DEC-31-1999 <PERIOD-START> JAN-01-1998 <PERIOD-END> DEC-31-1998 <CASH> 1,895 <SECURITIES> 2,366 <RECEIVABLES> 42,422 <ALLOWANCES> 1,013 <INVENTORY> 2,858 <CURRENT-ASSETS> 50,703 <PP&E> 130,290 <DEPRECIATION> 73,157 <TOTAL-ASSETS> 145,910 <CURRENT-LIABILITIES> 39,458 <BONDS> 68,774 <PREFERRED-MANDATORY> 0 <PREFERRED> 1 <COMMON> 104 <OTHER-SE> 36,205 <TOTAL-LIABILITY-AND-EQUITY> 145,910 <SALES> 0 <TOTAL-REVENUES> 197,439 <CGS> 0 <TOTAL-COSTS> 146,860 <OTHER-EXPENSES> 44,442 <LOSS-PROVISION> 559 <INTEREST-EXPENSE> 9,631 <INCOME-PRETAX> (3,494) <INCOME-TAX> 360 <INCOME-CONTINUING> (3,854) <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> (3,854) <EPS-PRIMARY> (.42) <EPS-DILUTED> (.42)