<ARTICLE> 5 <CIK> 0000822818 <NAME> CLEAN HARBORS <MULTIPLIER> 1,000 <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> DEC-31-1998 <PERIOD-START> JAN-01-1998 <PERIOD-END> JUN-30-1998 <CASH> 5,115 <SECURITIES> 1,747 <RECEIVABLES> 47,213 <ALLOWANCES> 940 <INVENTORY> 3,135 <CURRENT-ASSETS> 60,844 <PP&E> 131,100 <DEPRECIATION> 70,111 <TOTAL-ASSETS> 163,584 <CURRENT-LIABILITIES> 44,471 <BONDS> 77,862 <PREFERRED-MANDATORY> 0 <PREFERRED> 1 <COMMON> 102 <OTHER-SE> 37,189 <TOTAL-LIABILITY-AND-EQUITY> 163,584 <SALES> 93,967 <TOTAL-REVENUES> 93,967 <CGS> 70,319 <TOTAL-COSTS> 70,319 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 342 <INTEREST-EXPENSE> 4,658 <INCOME-PRETAX> (2,623) <INCOME-TAX> 180 <INCOME-CONTINUING> (2,803) <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> (2,803) <EPS-PRIMARY> (.30) <EPS-DILUTED> (.30)