
                                  Exhibit 10.9

                AGREEMENT AND THIRD AMENDMENT TO CREDIT AGREEMENT
                                 (May 31, 1994)


     THIS AGREEMENT AND THIRD AMENDMENT TO CREDIT AGREEMENT (this "Amendment")
is made and entered into as of May 31, 1994 by and among ALLWASTE, INC. (the
"Company"), a Delaware corporation, EACH OF THE FINANCIAL INSTITUTIONS SIGNATORY
HERETO (individually, a "Bank" and collectively, the "Banks") and TEXAS COMMERCE
BANK NATIONAL ASSOCIATION, a national banking association acting as agent for
the Banks (in such capacity, together with its successors in such capacity, the
"Agent").

RECITALS:

     A.  The  Company,  the  Agent  and the  Banks  have  entered  into a Credit
Agreement  dated as of November  30, 1993 (which such Credit  Agreement,  as the
same may have heretofore been amended, modified,  supplemented and restated from
time to time, is hereinafter called the "Credit Agreement").

     B. The Company, the Agent and the Banks now desire to amend the Credit
Agreement in certain respects to, among other things, modify certain financial
covenants contained in Section 5.3 of the Credit Agreement, modify the limit on
capital expenditures contained in Section 6.14 of the Credit Agreement, and make
certain other changes to the Credit Agreement, all as is more fully described
hereinbelow, which shall control over any conflicting or inconsistent recitals
above.

AGREEMENTS:

     NOW, THEREFORE, in consideration of the premises and the mutual agreements,
representations and warranties herein set forth, and for other good and valuable
consideration, the receipt and sufficiency of which are acknowledged, the
parties hereto do hereby agree as follows:

     1. FINANCIAL TESTS MODIFIED.  Section 5.3 of the Credit Agreement is hereby
amended in its entirety to be and read as follows:

          "5.3 Financial Tests.

          "(a) Have at all times a QUICK RATIO of not less than 1.00 to 1.00;

          "(b) have at all times during the periods indicated below, a TANGIBLE
NET WORTH TO DEBT RATIO of not less than (i) 0.25 to 1.00 from and including
August 1, 1994 to, but not including, November 4, 1994; (ii) 0.40 to 1.00 from
and including November 4, 1994 to, but not including, February 28, 1995, and
(iii) 0.45 to 1.00 on February 28, 1995 and at all times thereafter; provided,
that on the Step Up Date (whenever such date may occur) and at all times
thereafter, have a Tangible Net Worth to Debt Ratio of not less than 0.50 to
1.00;

          "(c) have at all times during the periods indicated below, a TANGIBLE
NET WORTH of not less than (i) $23,000,000 from and including August 1, 1994 to,
but not including, November 4, 1994, and (ii) the Tangible Net Worth Floor plus
the Tangible Net Worth Floor Adjustment, on November 4, 1994 and at all times
thereafter; and

          "(d) have at all times during the periods indicated below, a CASH FLOW
RATIO of not less than (i) 1.60 to 1.00 from and including August 1, 1994 to,
but not including, November 4, 1994, and (ii) 1.75 to 1.00 on November 4, 1994
and at all times thereafter.

     "As used in this Section, "Step Up Date" shall mean the date occurring
after the date hereof on which any issuance of any Stock of the Company (or any
Subsidiary of the Company to any Person other then the Company or another of its
Subsidiaries) pursuant to a public or private placement offering is completed."

     2. CAPITAL  EXPENDITURES.  The first sentence of Section 6.14 of the Credit
Agreement is hereby amended in its entirety to be and read as follows:

     "Make expenditures for fixed or capital assets on a consolidated basis
during any fiscal year of the Company (beginning with its 1994 fiscal year) in
excess of (i) $38,000,000 in the aggregate for the 1994 fiscal year, and (ii)
$30,000,000 in the aggregate for all fiscal years thereafter (provided, that, in
calculating said amount for any fiscal year, expenditures for fixed or capital
assets made by Subsidiaries of the Company, which were acquired during such
fiscal year and accounted for as a pooling of interest, shall not be included to
the extent that such expenditures were made prior to the time of acquisition)."

     3.  CONDITIONS.  No part of this Amendment shall become effective until the
Company shall have delivered (or shall have caused to be delivered) to the Banks
each of the following, in Proper Form:

          (a) the written  consent of all of the Guarantors to the execution and
     delivery of this Amendment and such other related  matters as the Banks may
     reasonably require; and

          (b) a Notice of Entire  Agreement,  DTPA  Waiver and Release of Claims
     executed by the Company and each of the Guarantors as of the date hereof.

     4. AMENDMENT FEE WAIVED. Each of the Banks hereby waives the payment of the
amendment  fee  contemplated  in Section 2.16 of the Credit  Agreement,  as such
amendment fee pertains to this Amendment, only.

     5. REPRESENTATIONS TRUE; No Default. The Company represents and warrants
that the representations and warranties contained in Section 4 of the Credit
Agreement and in the other Loan Documents are true and correct in all material
respects on and as of the date hereof as though made on and as of such date. The
Company hereby certifies that no Default or Event of Default under the Credit
Agreement or any of the other Loan Documents has occurred and is continuing as
of the date hereof.

     6. RATIFICATION. Except as expressly amended hereby, the Credit Agreement
and the other Loan Documents shall remain in full force and effect. In the event
of any conflict between this Amendment and the Credit Agreement or any of the
other Loan Documents (or any earlier modification of any o them), this Amendment
shall control. The Credit Agreement, as hereby amended, and all rights and
powers created thereby or thereunder and under the other Loan Docu ments are in
all respects ratified and confirmed and remain in full force and effect.

     7.  DEFINITIONS AND REFERENCES.  Terms used herein which are defined in the
Credit  Agreement or in the other Loan Documents shall have the meanings therein
ascribed to them. The term "Credit  Agreement" as used in the Credit  Agreement,
the other Loan Documents or any other  instrument,  documen or writing furnished
to the Agent or any of the Banks by the Company shall mean the Credit  Agreement
as hereby amended.

     8. MISCELLANEOUS. This Amendment (a) shall be binding upon and inure to the
benefit of the Company, the Banks and the Agent and their respective successors,
assigns, receivers and trustees (provided, however, that the Company shall not
assign its rights hereunder without the prior written consent of the Agent); (b)
may be modified or amended only by a writing signed by each party; (c) SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS AND
THE UNITED STATES OF AMERICA; (d) may be executed in several counterparts, and
by the parties hereto on separate counterparts, and each counterpart, when so
executed and delivered, shall constitute an original agreement, and all such
separate counterparts shall constitute but one and the same agreement; and (e)
together with the other Loan Documents, embodies the entire agreement and
understanding between the parties with respect to the subject matter hereof and
supersedes all prior agreements, consents and understandings relating to such
subject matter. The headings herein shall be accorded no significance in
interpreting this Amendment.

     IN WITNESS WHEREOF, the Company, the Banks and the Agent have caused this
Amendment to be signed by their respective duly authorized officers, effective
as of the date which first appears hereinabove.

                                                         ALLWASTE, INC.,
                                                         a Delaware corporation


 
                                                       By:_____________________
                                                            R. L. Nelson, Jr.
                                                            President

ATTEST:

_________________
Douglas M. Cerny,
Secretary
   
                                       -5-

                                             TEXAS COMMERCE BANK NATIONAL
                                             ASSOCIATION, a national banking
                                             association, as a Bank and as Agent


                                             By:_______________________________
                                                Richard L. Esdorn, III,
                                                Senior Vice President



                                      -6-

                                             NATIONSBANK OF TEXAS, N.A.,
                                             a national banking association


                                             By:_______________________________
                                                Frank T. Hundley,
                                                 Vice President





                                       -7-
   

                                             CITIBANK, N.A., a national
                                             banking association

                                             By:   ____________________________

                                             Name: ____________________________

                                             Title:____________________________



                                      -8-

                                             FIRST INTERSTATE BANK OF TEXAS,
                                             N.A, a national banking association


                                             By:_______________________________
                                                Carol D. Birkofer,
                                                Corporate Banking Officer

                                      -9-

    



                                             THE BANK OF NOVA SCOTIA,


               
                                             By:   ____________________________

                                             Name: ____________________________

                                             Title:____________________________


                                      -10-

                                             COMERICA BANK - TEXAS,
                                             a Texas banking association


                                             By:_______________________________
                                                Mitchell Schulman,
                                                Vice President

              


                                      -11-

                                             LTCB TRUST COMPANY, a New York
                                             Trust Company

                                             By:   ____________________________

                                             Name: ____________________________

                                             Title:____________________________

                                      -12-
