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                                                                     EXHIBIT 24

                                POWER OF ATTORNEY

       Know all by these presents, that the undersigned hereby constitutes
and appoints each of Alan S. McKim and Stephen H. Moynihan, signing singly,
the undersigned's true and lawful attorney-in-fact to:

       (1) execute for and on behalf of the undersigned, in the undersigned's
capacity as an officer and/or director of Clean Harbors, Inc. (the
"Company"), any and all documents required by the Securities and Exchange
Commission pursuant to the Securities Exchange Act of 1934 and the rules
thereunder, including, without limitation, Form 10-K;

       (2) do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and execute any
such document filing and timely file such form with the United States
Securities and Exchange Commission and any stock exchange or similar
authority; and

       (3) take any other action of any type whatsoever in connection with
the foregoing which, in the opinion of such attorney-in-fact, may be of
benefit to, and in the best interest of, or legally required by, the
undersigned.

       The undersigned hereby grants to each such attorney-in-fact full power
and authority to do and perform any and every act and thing whatsoever
requisite, necessary, or proper to be done in the exercise of any of the
rights and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's substitute or substitutes, shall
lawfully do or cause to be done by virtue of this power of attorney and the
rights and powers herein granted. The undersigned acknowledges that the
foregoing attorneys-in-fact, in serving in such capacity at the request of
the undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934.

       This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required with respect to the undersigned's capacity
as an officer and/or director and/or holdings of and transactions in
securities issued by the Company, unless earlier revoked by the undersigned
in a signed writing delivered to the foregoing attorneys-in-fact.

       IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney
to be executed as of this 26th day of March, 2005.


                                  Signature
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                              /s/ John D. Barr
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                           /s/ John P. DeVillars
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                            /s/ John F. Kaslow
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                         /s/ Daniel J. McCarthy
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                          /s/ John T. Preston
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                          /s/ Andrea Robertson
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                          /s/ Thomas J. Shields
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                           /s/ Lorne R. Waxlax
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