<ARTICLE> 5 <CIK> 0000822818 <NAME> CLEAN HARBORS <MULTIPLIER> 1,000 <PERIOD-TYPE> 9-MOS <FISCAL-YEAR-END> DEC-31-1998 <PERIOD-START> JAN-01-1998 <PERIOD-END> SEP-30-1998 <CASH> 1,970 <SECURITIES> 2,266 <RECEIVABLES> 44,611 <ALLOWANCES> 952 <INVENTORY> 3,019 <CURRENT-ASSETS> 55,588 <PP&E> 131,740 <DEPRECIATION> 71,917 <TOTAL-ASSETS> 156,812 <CURRENT-LIABILITIES> 41,325 <BONDS> 75,315 <PREFERRED-MANDATORY> 0 <PREFERRED> 1 <COMMON> 104 <OTHER-SE> 36,088 <TOTAL-LIABILITY-AND-EQUITY> 156,812 <SALES> 144,851 <TOTAL-REVENUES> 144,851 <CGS> 108,012 <TOTAL-COSTS> 108,012 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 519 <INTEREST-EXPENSE> 7,010 <INCOME-PRETAX> (3,668) <INCOME-TAX> 270 <INCOME-CONTINUING> (3,938) <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> (3,938) <EPS-PRIMARY> 0.42 <EPS-DILUTED> 0.42