<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE C0NSOLIDATED FINANCIAL STATEMENTS OF CLEAN HARBORS, INC. AND SUBSIDIARIES FOR THE YEAR ENDED DECEMBER 31, 1999, AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. </LEGEND> <MULTIPLIER> 1,000 <PERIOD-TYPE> YEAR <FISCAL-YEAR-END> DEC-31-1999 <PERIOD-START> JAN-01-1999 <PERIOD-END> DEC-31-1999 <CASH> 2,783 <SECURITIES> 1,116 <RECEIVABLES> 44,937 <ALLOWANCES> 1,157 <INVENTORY> 2,808 <CURRENT-ASSETS> 51,703 <PP&E> 137,061 <DEPRECIATION> 80,849 <TOTAL-ASSETS> 145,247 <CURRENT-LIABILITIES> 37,138 <BONDS> 72,683 <PREFERRED-MANDATORY> 0 <PREFERRED> 1 <COMMON> 108 <OTHER-SE> 34,062 <TOTAL-LIABILITY-AND-EQUITY> 145,247 <SALES> 0 <TOTAL-REVENUES> 202,965 <CGS> 0 <TOTAL-COSTS> 149,637 <OTHER-EXPENSES> 46,008 <LOSS-PROVISION> 683 <INTEREST-EXPENSE> 8,599 <INCOME-PRETAX> (1,962) <INCOME-TAX> 282 <INCOME-CONTINUING> (1,982) <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> (2,244) <EPS-BASIC> (0.25) <EPS-DILUTED> (0.25)