On January 17, 2013, Clean Harbors, Inc. (the "Company") and one of the Company's Canadian subsidiaries (the "Canadian Borrower") entered into a fourth amended and restated credit agreement providing for a revolving credit facility under which Bank of America, N.A. ("BofA") is the administrative agent (the "Agent") for the lenders and BofA, JP Morgan Chase Bank, N.A. or their respective affiliates are the issuing banks for letters of credit issued under the facility. Under the amended and restated facility, the Company has the right to obtain revolving loans and letters of credit for a combined maximum of up to $300.0 million (with a sub-limit of $250.0 million for letters of credit) and the Canadian Borrower has the right to obtain revolving loans and letters of credit for a combined maximum of up to $100.0 million (with a $75.0 million sub-limit for letters of credit). Availability under the U.S. line is subject to a borrowing base comprised of 85% of the eligible accounts receivable of the Company and its U.S. subsidiaries plus 100% of cash deposited in a controlled account with the Agent, and availability under the Canadian line is subject to a borrowing base comprised of 85% of the eligible accounts receivable of the Company's Canadian subsidiaries plus 100% of cash deposited in a controlled account with the Agent's Canadian affiliate. The facility will expire on January 17, 2018.

Borrowings under the revolving credit facility will bear interest at a rate of, at the Company's option, either (i) LIBOR plus an applicable margin ranging from 1.50% to 2.00% per annum based primarily on the level of the Company's consolidated fixed charge coverage ratio for the most recently completed four fiscal quarter measurement period or (ii) BofA's base rate plus an applicable margin ranging from 0.50% to 1.00% per annum based primarily on such consolidated fixed charge coverage ratio. There is also an unused line fee, calculated on the then unused portion of the lenders' $400.0 million maximum commitments, ranging from 0.25% to 0.375% per annum of the unused commitment. For outstanding letters of credit, the Company will pay to the lenders a fee equal to the then applicable LIBOR margin described above, and to the issuing banks a standard fronting fee and customary fees and charges in connection with all amendments, extensions, draws and other actions with respect to letters of credit.

The Company's obligations under the revolving credit facility (including revolving loans and reimbursement obligations for outstanding letters of credit) are guaranteed by all of the Company's U.S. subsidiaries and secured by a first lien on substantially all of the Company's and its U.S. subsidiaries' assets. The Canadian Borrower's obligations under the facility are guaranteed by substantially all of the Company's Canadian subsidiaries and secured by a first lien on the accounts receivable of the Canadian subsidiaries. The Company and its U.S. subsidiaries guarantee the obligations of the Canadian subsidiaries under the facility, but the Canadian subsidiaries do not guarantee and are not otherwise responsible for the obligations of the Company and its U.S. subsidiaries.

Under the revolving credit facility, the Agent would have the right to exercise dominion over the Company's and its subsidiaries' cash (to the extent such cash represents the proceeds of accounts receivable) if the Company's "Liquidity" is less than the greater of (i) $50.0 million and (ii) 12.5% of the aggregate commitments of the lenders under the facility. Liquidity is defined as the sum of (a) the Company's then availability under the facility and (b) the lesser of
(i) the Canadian Borrower's then availability under the facility and (ii) 60% of the lenders' aggregate commitments to the Canadian Borrower. If Liquidity should be less than the greater of (i) $40.0 million and (ii) 10.0% of the aggregate commitments, the Company will be required to thereafter maintain a consolidated fixed charge coverage ratio of at least 1.00 to 1.00. In addition, the facility contains covenants which will restrict the Company's future ability to make certain types of acquisitions, debt prepayments, investments and distributions if Liquidity (on a pro forma basis after giving effect to such events) is less than between 35% and 15% (depending upon the type of restricted event) of the lenders' aggregate commitments or, if the Company's consolidated fixed charge coverage ratio for the most recently completed four fiscal quarters is at least 1.00 (or, in certain cases, 1.10) to 1.00, less than 17.5% or 15% (depending upon the type of restricted event) of the aggregate commitments.

A copy of the credit agreement is filed as an exhibit to this report and is incorporated herein by reference. The foregoing description of the terms of the credit agreement is qualified in its entirety by reference to the full text of such agreement.

(d) Exhibits

4.33 E-1   Fourth Amended and Restated Credit Agreement dated as of January 17,
           2013 among Clean Harbors, Inc., as the U.S. Borrower, Clean Harbors
           Industrial Services Canada, Inc., as the Canadian Borrower, Bank of
           America, N.A., as Administrative Agent and the Lenders party thereto

4.33I      Security Agreement (U.S. Domiciled Loan Parties) dated as of January 17,
           2013 among Clean Harbors, Inc., as the U.S. Borrower and a Grantor, the
           subsidiaries of Clean Harbors, Inc. listed on Annex A thereto or that
           thereafter become a party thereto as Grantors, and Bank of America,
           N.A., as Agent