<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REGISTRANT'S FINANCIAL STATEMENTS AND RELATED NOTES CONTAINED IN FORM 10-Q AS
FILED HEREWITH, AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS AND RELATED NOTES.
</LEGEND>
<CIK> 0000822818
<NAME> CLEAN HARBORS,INC.

                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               SEP-30-1999
<CASH>                                           2,219
<SECURITIES>                                     1,096
<RECEIVABLES>                                   47,880
<ALLOWANCES>                                     1,333
<INVENTORY>                                      2,839
<CURRENT-ASSETS>                                55,692
<PP&E>                                         135,772
<DEPRECIATION>                                  78,854
<TOTAL-ASSETS>                                 149,403
<CURRENT-LIABILITIES>                           40,077
<BONDS>                                         75,818
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          1
<COMMON>                                           107
<OTHER-SE>                                      34,467
<TOTAL-LIABILITY-AND-EQUITY>                   149,403
<SALES>                                              0
<TOTAL-REVENUES>                               150,368
<CGS>                                                0
<TOTAL-COSTS>                                  144,749
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                   512
<INTEREST-EXPENSE>                               6,735
<INCOME-PRETAX>                                (1,628)
<INCOME-TAX>                                       192
<INCOME-CONTINUING>                            (1,820)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   (1,820)
<EPS-BASIC>                                      (.20)
<EPS-DILUTED>                                    (.20)