<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)