September 15, 2005


By facsimile to (617) 523-6215 and U.S. Mail


Mr. Alan S. McKim
Chairman, President, and Chief Executive Officer
Clean Harbors, Inc.
1501 Washington Street
Braintree, MA 02184-7535

Re:	Clean Harbors, Inc.
	Pre-effective Amendment 1 to Registration Statement on Form
S-3
	Filed August 23, 2005
File No. 333-126205

Dear Mr. McKim:

	We reviewed the filing and have the comments below.

1. If applicable, comments on the S-4 filed by Clean Harbors, Inc.
or
Clean Harbors on June 28, 2005 and the 10-K filed by Clean Harbors
on
March 31, 2005 and subsequent Exchange Act reports are comments on
the S-3 and vice versa.

Exhibit 5.1

2. Delete the phrase "upon the issuance of an appropriate order by
the Commission allowing the Registration Statement to become
effective" in the fourth paragraph on page 1.

Closing

	File an amendment to the S-3 in response to the comments.  To
expedite our review, Clean Harbors may wish to provide us three
marked courtesy copies of the amendment.  Include with the filing
any
supplemental information requested and a cover letter tagged as
correspondence that keys the responses to the comments.  If Clean
Harbors thinks that compliance with any of the comments is
inappropriate, provide the basis in the letter.  We may have
additional comments after review of the amendment, the responses
to
the comments, and any supplemental information.

	We urge all persons responsible for the accuracy and adequacy
of
the disclosure in the registration statement reviewed by us to
ensure
that they have provided all information investors require for an
informed decision.  Since Clean Harbors and its management are in
possession of all facts relating to the disclosure in the
registration statement, they are responsible for the adequacy and
accuracy of the disclosures that they have made.

      If Clean Harbors requests acceleration of the registration
statement`s effectiveness, Clean Harbors should furnish a letter
at
the time of the request, acknowledging that:

* Should the Commission or the staff acting by delegated authority
declare the registration statement effective, it does not
foreclose
the Commission from taking any action on the filing.

* The action of the Commission or the staff acting by delegated
authority in declaring the registration statement effective does
not
relieve Clean Harbors from its full responsibility for the
adequacy
and accuracy of the disclosure in the registration statement.

* Clean Harbors may not assert our comments and the declaration of
the registration statement`s effectiveness as a defense in any
proceedings initiated by the Commission or any person under the
United States` federal securities laws.

	The Commission`s Division of Enforcement has access to all
information that Clean Harbors provides us in our review of the
registration statement or in response to our comments on the
registration statement.

	We will consider a written request for acceleration of the
registration statement`s effectiveness under Rule 461 of
Regulation C
under the Securities Act as confirmation that those requesting
acceleration are aware of their responsibilities under the
Securities
Act and the Exchange Act as they relate to the proposed public
offering of the securities specified in the registration
statement.
We will act on the request and by delegated authority grant
acceleration of the registration statement`s effectiveness.

	You may direct questions on accounting comments to Gustavo A.
Rodriguez, Staff Accountant, at (202) 551-3752 or Nudrat S. Salik,
Senior Staff Accountant, at (202) 551-3692.

You may direct questions on other comments and disclosure issues
to
Edward M. Kelly, Senior Counsel, at (202) 551-3728 or Christopher
B.
Edwards, Special Counsel, at (202) 551-3742.

Very truly yours,





Pamela A. Long

Assistant Director

cc:	C. Michael Malm, Esq.
	Davis, Malm & D`Agostine, P.C.
	1 Boston Place
	Boston, MA 02108



Mr. Alan S. McKim
September 15, 2005
Page 1








UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

         DIVISION OF
CORPORATION FINANCE