<PAGE>
                                                                   EXHIBIT 10.18
                                                                  EXECUTION COPY


                              AMENDMENT dated as of December 17, 2002 (this
                        "Amendment"), to the Credit Agreement dated as of July
                        21, 1999 (as amended, supplemented or otherwise modified
                        from time to time, the "Credit Agreement"), among ALLIED
                        WASTE INDUSTRIES, INC. ("Allied Waste"), ALLIED WASTE
                        NORTH AMERICA, INC. (the "Borrower"); the lenders party
                        thereto (the "Lenders"); and JPMORGAN CHASE BANK, as
                        administrative agent (in such capacity, the
                        "Administrative Agent") and collateral agent (in such
                        capacity, the "Collateral Agent") for the Lenders and as
                        collateral trustee (in such capacity, the "Collateral
                        Trustee") for the Shared Collateral Secured Parties.

            The Borrower has requested that the Lenders amend certain provisions
of the Credit Agreement, and the Lenders are willing so to amend the Credit
Agreement, on the terms and subject to the conditions set forth herein.
Capitalized terms used herein and not otherwise defined herein shall have the
meanings assigned to such terms in the Credit Agreement.

            Accordingly, in consideration of the mutual agreements herein
contained and other good and valuable consideration, the sufficiency and receipt
of which are hereby acknowledged, the parties hereto agree as follows:

            SECTION 1. Amendment of Credit Agreement. The Credit Agreement is
hereby amended, effective as of the Amendment Effective Date (as defined in
Section 4), as follows:

            (a) Amendment of Section 1.01. Section 1.01 is amended as follows:

            (i) The definition of "Consolidated EBITDA" is amended by replacing
      the first reference to "Allied Waste and its Restricted Subsidiaries" with
      a reference to "Allied Waste, its Restricted Subsidiaries and the
      Securitization Vehicles" and by revising clause (g) thereof to read as
      follows:
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                                                                               2

                  "(g) all non-recurring cash charges incurred in connection
            with Permitted Acquisitions, Investments permitted under Sections
            6.05A(a), (h) or (i) or Sections 6.05B(a), (h) or (i), Indebtedness
            permitted under Section 6.01A or Section 6.01B, and Securitizations
            permitted under Sections 6.05A and 6.06A,".

            (ii) The definition of "Consolidated Interest Expense" is amended by
      inserting "without duplication, (i)" after the first reference to "for any
      period," and adding a new clause (ii) after clause (e) as follows:

                  "and (ii) all interest in respect of Third Party Securities
                  issued by Securitization Vehicles in connection with
                  Securitizations permitted by Sections 6.05A and 6.06A and
                  accrued or capitalized during such period (whether or not
                  actually paid during such period), net of interest income of
                  the Securitization Vehicles."

            (iii) The definition of "Excess Cash Flow" is amended by:

            (A) replacing the reference in clause (a)(i) thereof to "Allied
      Waste and its Restricted Subsidiaries" with a reference to "Allied Waste,
      its Restricted Subsidiaries and the Securitization Vehicles";

            (B) inserting a new parenthetical at the end of clause (b)(vi)
      thereof to read as follows:

                  "(it being understood and agreed that the issuance of Third
            Party Securities in a Securitization permitted pursuant to Sections
            6.05A and 6.06A shall not be deemed to constitute a refinancing or
            replacement of any Loans outstanding under this Agreement)"; and
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                                                                               3

            (C) deleting the word "and" at the end of clause (b)(ix) thereof and
      replacing it with a comma and inserting a new clause (b)(xi) to read as
      follows:

                  "and (xi) repayments and prepayments of Third Party Securities
            made by Allied Waste, its Restricted Subsidiaries and the
            Securitization Vehicles during such fiscal year (excluding any
            repayments made by Securitization Vehicles from the proceeds from
            the issuance of securities by Securitization Vehicles); provided,
            however, that all such repayments and prepayments (other than
            scheduled and mandatory principal repayments) made pursuant to this
            clause (b)(xi) may be made only (A) with the proceeds of collections
            of accounts receivable and (B) in connection with the dissolution or
            winding-up of the Securitization Vehicle that issued such Third
            Party Securities".

            (iv) The definition of "Net Available Proceeds" is amended by
      deleting the word "and" after clause (a)(2) thereof, replacing the period
      at the end of clause (a)(3) thereof with "; and" and inserting a new
      clause (a)(4) to read as follows:

                  "(4) in the case of a Securitization permitted by Sections
            6.05A and 6.06A, such Net Available Proceeds shall be net of,
            without duplication, (x) any amounts incurred in connection with
            such Securitization by the Borrower or any of its Subsidiaries set
            forth in clause (1) of this definition and (y) any other fees, costs
            or expenses paid in cash by the applicable Securitization Vehicle in
            connection with such Securitization; provided, however, that any
            Sellers' Retained Interests shall not be deemed to constitute a cost
            or expense for purposes of calculating such Net Available Proceeds."

            (v) The definition of "Prepayment Event" is amended (A) by deleting
      the word "and" between clauses (i) and (ii) of clause (a) thereof,
      inserting a comma in place thereof and adding a new
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                                                                               4

      clause (iii) at the end of clause (a) to read as follows:

                  ", and (iii) Securitizations permitted by Sections 6.05A and
            6.06A hereunder"; and

                  (B) by deleting the word "or" at the end of clause (c),
            replacing the period at the end of clause (d) with "; or" and adding
            a new clause (e) to read as follows:

                  "(e) any Asset Sale consisting of a Securitization permitted
            by Sections 6.05A and 6.06A hereunder."

            (vi) The definition of "Total Indebtedness" is amended by deleting
      the word "and" at the end of clause (a) thereof, replacing the period at
      the end of clause (b) with a reference to "; and" and inserting a new
      clause (c) to read as follows:

                        "(c) the aggregate principal, stated or invested amount
                  of any Third Party Securities outstanding at such time."

            (vii) The definition of "2001 Indenture" is amended to read as
      follows:

                  "'2001 Indenture' means (i) one or more supplemental
            indentures, dated on or after January 25, 2001 and prior to December
            31, 2004, to the AWNA Senior Note Indenture and (ii) any other
            indenture governing Senior Indebtedness entered into on or after
            January 25, 2001 and prior to December 31, 2004."

            (viii) The definition of "2001 Senior Notes" is amended to read as
      follows:

                  "'2001 Senior Notes' means senior secured notes of AWNA or
            Allied Waste issued on or prior to December 31, 2004, pursuant to
            the 2001 Indenture, provided that the 2001 Senior Notes do not have
            a maturity date or any scheduled
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                                                                               5

            amortization until after the Tranche C Maturity Date."

            (ix) The following definitions are added in their appropriate
      alphabetical order:

                  "'Securitization' means any transaction or series of
            transactions entered into by the Borrower or any Restricted
            Subsidiary pursuant to which the Borrower or such Restricted
            Subsidiary, as the case may be, sells, conveys or otherwise
            transfers to a Securitization Vehicle Securitization Assets of the
            Borrower or such Restricted Subsidiary (or grants a security
            interest in such Securitization Assets transferred or purported to
            be transferred to such Securitization Vehicle), and which
            Securitization Vehicle finances the acquisition of such
            Securitization Assets (i) with proceeds from the issuance of Third
            Party Securities, (ii) with Sellers' Retained Interests or (iii)
            with proceeds from the sale or collection of Securitization Assets
            previously purchased by such Securitization Vehicle."

                  "'Securitization Assets' means any accounts receivable owed to
            the Borrower or any Restricted Subsidiary (whether now existing or
            arising or acquired in the future) arising in the ordinary course of
            business from the sale of goods or services, all collateral securing
            such accounts receivable, all contracts and contract rights and all
            guarantees or other obligations in respect of such accounts
            receivable, all proceeds of such accounts receivable and other
            assets (including contract rights) which are of the type customarily
            transferred in connection with securitizations of accounts
            receivable and which are sold by the Borrower or a Restricted
            Subsidiary to a Securitization Vehicle in connection with a
            Securitization permitted by Sections 6.05A and 6.06A."

                  "'Securitization Vehicle' means a Person that is a direct
            wholly owned Subsidiary of the
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                                                                               6

            Borrower or a Restricted Subsidiary formed for the purpose of
            effecting one or more Securitizations to which the Borrower or
            Restricted Subsidiaries transfer Securitization Assets and which, in
            connection therewith, issues Third Party Securities; provided that
            (i) such Securitization Vehicle shall engage in no business other
            than the purchase of Securitization Assets pursuant to
            Securitizations permitted by Sections 6.05A and 6.06A, the issuance
            of Third Party Securities or other funding of such Securitizations
            and any activities reasonably related thereto, (ii) such
            Securitization Vehicle is an Unrestricted Subsidiary under this
            Agreement and an "Unrestricted Subsidiary" under each of the AWNA
            Senior Note Indenture and the 2001 Indenture and (iii) such
            Securitization Vehicle shall not be a Subsidiary of BFI or any
            Restricted Subsidiary that is or becomes a party to the Shared
            Collateral Pledge Agreement or the Shared Collateral Security
            Agreement."

                  "'Sellers' Retained Interests' means the debt or equity
            interests held by the Borrower or any Restricted Subsidiary in a
            Securitization Vehicle to which Securitization Assets have been
            transferred in a Securitization permitted by Sections 6.05A and
            6.06A, including any such debt or equity received in consideration
            for the Securitization Assets transferred."

                  "'Third Party Securities' means, with respect to any
            Securitization, notes, bonds or other debt instruments, beneficial
            interests in a trust, undivided ownership interests in receivables
            or other securities issued for cash consideration by the relevant
            Securitization Vehicle to banks, financing conduits, investors or
            other financing sources (other than Allied Waste and the
            Subsidiaries) the proceeds of which are used to finance, in whole or
            in part, the purchase by such Securitization Vehicle of
            Securitization Assets in a Securitization. The amount of any Third
            Party Securities shall be
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                                                                               7

            deemed to equal the aggregate principal, stated or invested amount
            of such Third Party Securities which are outstanding at such time."

            (b) Amendment of Section 2.11. Section 2.11(c) is amended by:

            (i) inserting "or Section 6.01A(xix)" immediately after the
      reference to "Section 6.01A(xvi)" in the second proviso to the first
      sentence thereof;

            (ii) replacing the reference to "Specified Assets" with a reference
      to "Securitization Assets" in the second proviso to the first sentence
      thereof; and

            (iii) deleting the last sentence thereof (dealing with the
      application of Net Available Proceeds from issuances of 2001 Senior Notes)
      and inserting in place thereof the following:

                  "Notwithstanding any provision of this Agreement to the
            contrary, in the case of a Prepayment Event referred to in clause
            (e) of the definition of "Prepayment Event", the Borrower and/or any
            applicable Restricted Subsidiary will for purposes hereof (i) be
            deemed to have received a cash payment in respect of such Prepayment
            Event to the extent that the Borrower or such Restricted Subsidiary,
            as the case may be, receives a cash payment in respect of the
            applicable Securitization Assets from the applicable Securitization
            Vehicle and such cash payment is derived from proceeds from the
            issuance of Third Party Securities and (ii) will not be deemed to
            have received a cash payment from such Prepayment Event to the
            extent that such Prepayment Event occurs in connection with ongoing
            sales of Securitization Assets to such Securitization Vehicle that
            are purchased by it with the proceeds from collections of
            Securitization Assets previously purchased by it pursuant to such
            Securitization."
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                                                                               8

            (c) Amendment of Section 5.10A. Section 5.10A is amended by
inserting "(other than a Securitization Vehicle)" immediately after the
reference to "any Unrestricted Subsidiary" in clause (iv) of the final sentence
of such Section.

            (d) Amendment of Section 6.01A. Section 6.01A(a) is amended by:

            (i) revising clause (xix) thereof to read as follows:

                  "(xix) up to $3,150,000,000 (which includes the aggregate
            principal amount of 2001 Senior Notes issued prior to December 17,
            2002) aggregate principal amount of 2001 Senior Notes issued by the
            Borrower or Allied Waste pursuant to the 2001 Indenture, and the
            related Guarantees, if any, by Allied Waste and/or its Subsidiaries
            of the issuer's obligations with respect to such 2001 Senior Notes;
            provided, however, that no more than $1,500,000,000 aggregate
            principal amount of 2001 Senior Notes may be issued on or after
            January 1, 2003; and provided further, however, that the Net
            Available Proceeds from the issuance of 2001 Senior Notes shall be
            applied to the prepayment of Term Loans in accordance with Section
            2.11(c);" and

            (ii) deleting the word "and" at the end of clause (xx), adding the
      word "and" at the end of clause (xxi), and adding a new clause (xxii) to
      read as follows:

                  "(xxii) Indebtedness consisting of representations,
            warranties, covenants and indemnities made by, and repurchase and
            other obligations of, the Borrower or any Restricted Subsidiary in
            connection with Securitizations permitted by Sections 6.05A and
            6.06A; provided that such representations, warranties, covenants,
            indemnities and repurchase and other obligations are of the type
            customarily included in securitizations of accounts receivable
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                                                                               9

            intended to constitute true sales of such accounts receivable to a
            securitization vehicle."

            (e) Amendment of Section 6.02A. Section 6.02A is amended by deleting
the word "and" at the end of clause (i), inserting "; and" in place of the
period after clause (l), and adding a new clause (m) to read as follows:

                  "(m) Liens in favor of any Securitization Vehicle or any
            collateral agent on Securitization Assets transferred or purported
            to be transferred to such Securitization Vehicle in connection with
            Securitizations permitted by Sections 6.05A and 6.06A."

            (f) Amendment of Section 6.05A. Section 6.05A is amended by deleting
the word "and" at the end of clause (r), inserting "; and" in place of the
period after clause (s), and adding a new clause (t) to read as follows:

            "(t) investments consisting of Sellers' Retained Interests in
      Securitizations permitted by Section 6.06A."

            (g) Amendment of Section 6.06A. Section 6.06A is amended by deleting
the word "and" at the end of clause (e), inserting "; and" in place of the
period after clause (f), and adding a new clause (g) to read as follows:

            "(g) the Borrower or any Restricted Subsidiary may sell
      Securitization Assets to one or more Securitization Vehicles in
      Securitizations; provided that (i) each such Securitization is effected on
      market terms, (ii) the aggregate amount of Third Party Securities in
      respect of all such Securitizations does not exceed $200,000,000 at any
      time outstanding, (iii) the aggregate amount of the Sellers' Retained
      Interests in such Securitizations does not exceed $125,000,000 at any time
      outstanding, (iv) the proceeds to each such Securitization Vehicle from
      the issuance of Third
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                                                                              10

      Party Securities are applied substantially simultaneously with receipt
      thereof to the purchase from the Borrower or Restricted Subsidiaries of
      Securitization Assets and an amount equal to 100% of the Net Available
      Proceeds from each such Securitization is applied to the mandatory
      repayment of Loans in accordance with Section 2.11(c) and (v) the Equity
      Interests and Sellers' Retained Interests in respect of each such
      Securitization Vehicle shall be pledged to the Shared Collateral Secured
      Parties pursuant to the Shared Collateral Pledge Agreement or Shared
      Collateral Security Agreement or the Secured Parties pursuant to the
      Non-Shared Collateral Pledge Agreement or Non-Shared Collateral Security
      Agreement, as the case may be."

            (h) Amendment of Section 6.07A. Section 6.07A is amended by deleting
the word "and" at the end of clause (c) and inserting a comma in place thereof
and adding a new clause (e) to read as follows:

                  "and (e) Hedging Agreements entered into the ordinary course
            of business in connection with any Securitizations permitted by
            Sections 6.05A and 6.06B."

            (i) Amendment of Section 6.09A. Clause (c) of Section 6.09A is
amended by deleting the word "and" at the end of clause (vi) and inserting a
comma in place thereof and by adding a new clause (viii) to read as follows:

                  "; or (viii) Securitizations permitted by Sections 6.05A and
            6.06A."

            (j) Amendment of Section 6.11A. Clause (b) of Section 6.11A is
amended by inserting a new clause (w) immediately after the words "other than"
to read as follows:

                  "(w) payments of Indebtedness incurred pursuant to Section
            6.01A(a)(xxii),".

            (k) Article VI-A of the Credit Agreement is amended by adding a new
Section 6.17A to read as follows:
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                                                                              11

            "SECTION 6.17A. Commingling of Accounts. The Borrower will not, nor
will it cause or permit any Restricted Subsidiary to, commingle amounts relating
to Securitization Assets sold pursuant to a Securitization with cash or any
other amounts of the Borrower and its Subsidiaries other than the temporary
commingling of collections on and proceeds of any accounts receivable or related
assets of the Borrower and its Subsidiaries, in each case as may be necessary to
identify and sort such collections and proceeds."

            (l) Article IX of the Credit Agreement is amended by adding a new
Section 9.16 to read as follows:

            "SECTION 9.16. Securitization Vehicles. (a) Each Lender, the
      Administrative Agent, the Collateral Agent and the Collateral Trustee
      agrees that, prior to the date that is one year and one day after the
      payment in full of all the obligations in respect of any Third Party
      Securities, (i) the Collateral Agent and other Secured Parties shall not
      be entitled, whether before or after the occurrence of any Event of
      Default, to (A) institute against, or join any other Person in instituting
      against, any Securitization Vehicle any bankruptcy, reorganization,
      arrangement, insolvency or liquidation proceeding under the laws of the
      United States or any State thereof, (B) transfer and register the capital
      stock of any Securitization Vehicle in the name of a Secured Party or any
      designee or nominee of a Secured Party, (C) foreclose such security
      interest regardless of the bankruptcy or insolvency of any Loan Party, (D)
      exercise any voting rights granted or appurtenant to such capital stock of
      any Securitization Vehicle or (E) enforce any right that the holder of any
      such capital stock of any Securitization Vehicle might otherwise have to
      liquidate, consolidate, combine, collapse or disregard the entity status
      of such Securitization Vehicle and (ii) the Collateral Agent and other
      Secured Parties hereby waive and release any right to require (A) that any
      Securitization Vehicle be in any manner merged, combined, collapsed or
      consolidated with or into any Loan Party, including
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                                                                              12

      by way of substantive consolidation in a bankruptcy case or (B) that the
      status of any Securitization Vehicle as a separate entity be in any
      respect disregarded; provided, however, that the provisions of this
      Section 9.16 shall cease to be of any force or effect when the Obligations
      have been paid in full and the Revolving Commitments have been terminated
      or expired; and provided further, that the provisions hereof will not
      apply to a Lender, the Administrative Agent, the Collateral Agent or the
      Collateral Trustee in its capacity as a holder of Third Party Securities.

            (b) Upon the transfer by the Borrower or any Restricted Subsidiary
      of Securitization Assets to a Securitization Vehicle in a Securitization
      permitted by Sections 6.05A and 6.06A, the Liens with respect to such
      Securitization Assets under the Security Agreements shall automatically be
      released."

            SECTION 2. Representations and Warranties. To induce the other
parties hereto to enter into this Amendment, each of the Borrower and Allied
Waste represents and warrants to each of the Lenders, the Administrative Agent,
the Collateral Agent and the Collateral Trustee that, as of the Amendment
Effective Date:

            (a) This Amendment has been duly authorized, executed and delivered
      by it and constitutes its legal, valid and binding obligation, enforceable
      against it in accordance with its terms except as such enforceability may
      be limited by bankruptcy, insolvency, reorganization, moratorium or other
      similar laws affecting creditors' rights generally and by general
      principles of equity (regardless of whether such enforceability is
      considered in a proceeding at law or in equity).

            (b) The representations and warranties set forth in Article III of
      the Credit Agreement are true and correct in all material respects on and
      as of the Amendment Effective Date with the same effect as though made on
      and as of the Amendment Effective Date, except to the extent such
      representations and warranties expressly relate to an earlier date (in
      which case they were true
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                                                                              13

and correct in all material respects as of such earlier date).

            (c) After giving effect to the agreements and waivers herein, no
Default or Event of Default has occurred and is continuing.

            SECTION 3. Shared Collateral Security Documents. Allied Waste, the
Borrower and the Required Lenders hereby acknowledge that the amendments dated
as of January 25, 2001 to each of the Shared Collateral Security Agreement, the
Shared Collateral Pledge Agreement and the Collateral Trust Agreement will
permit the Liens on the collateral under the Shared Collateral Security
Agreement and the Shared Collateral Pledge Agreement to secure 2001 Senior Notes
in an aggregate principal amount of up to $3,150,000,000 on a pari passu basis
with the Senior Obligations, the AWNA Senior Notes and the BFI Indenture Debt.

            SECTION 4. Effectiveness. This Amendment shall become effective on
the first date on which the Administrative Agent shall have received
counterparts of this Amendment that, when taken together, bear the signatures of
the Required Lenders, the Borrower and Allied Waste which date shall in no event
be later than 30 days after the execution of this Amendment (the "Amendment
Effective Date").

            SECTION 5. Effect of Amendment. Except as expressly set forth
herein, this Amendment shall not by implication or otherwise limit, impair,
constitute a waiver of or otherwise affect the rights and remedies of the
Lenders, the Administrative Agent, the Collateral Agent or the Collateral
Trustee under the Credit Agreement or any other Loan Document, and shall not
alter, modify, amend or in any way affect any of the terms, conditions,
obligations, covenants or agreements contained in the Credit Agreement or any
other provision of the Credit Agreement or of any other Loan Document, all of
which are ratified and affirmed in all respects and shall continue in full force
and effect. Nothing herein shall be deemed to entitle the Borrower or Allied
Waste to a consent to, or a waiver, amendment, modification or other change of,
any of the terms,
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                                                                              14

conditions, obligations, covenants or agreements contained in the Credit
Agreement or any other Loan Document in similar or different circumstances. This
Amendment shall apply and be effective only with respect to the provisions of
the Credit Agreement specifically referred to herein.

            SECTION 6. Costs and Expenses. The Borrower and Allied Waste,
jointly and severally, agree to reimburse the Administrative Agent for its
reasonable out-of-pocket expenses in connection with this Amendment, including
the reasonable fees, charges and disbursements of counsel for the Administrative
Agent.

            SECTION 7. Counterparts. This Amendment may be executed in any
number of counterparts and by different parties hereto in separate counterparts,
each of which when so executed and delivered shall be deemed an original, but
all such counterparts together shall constitute but one and the same instrument.
Delivery of any executed counterpart of a signature page of this Amendment by
facsimile transmission shall be as effective as delivery of a manually executed
counterpart hereof.

            SECTION 8. Applicable Law. THIS AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

            SECTION 9. Headings. The headings of this Amendment are for purposes
of reference only and shall not limit or otherwise affect the meaning hereof.
<PAGE>
            IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be duly executed by their duly authorized officers, all as of the date and year
first above written.

                                               ALLIED WASTE INDUSTRIES, INC.,

                                                 by
                                                   -----------------------------
                                                   Name:
                                                   Title:

                                               ALLIED WASTE NORTH AMERICA, INC.,

                                                 by
                                                   -----------------------------
                                                   Name:
                                                   Title:

                                               JPMORGAN CHASE BANK,
                                               individually and as
                                               Administrative Agent, Collateral
                                               Agent and Collateral Trustee,

                                                 by
                                                   -----------------------------
                                                   Name:
                                                   Title:
<PAGE>
                                                                              16

                                               SIGNATURE PAGE TO AMENDMENT DATED
                                               AS OF DECEMBER 17, 2002 TO THE
                                               ALLIED WASTE NORTH AMERICA, INC.
                                               CREDIT AGREEMENT DATED AS OF
                                               JULY 21, 1999, AS AMENDED

                                               Name of Institution:

                                               ---------------------------------

                                                       by

                                               ------------------------------
                                                   Name:
                                                   Title: