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                                                                    EXHIBIT 4.10

                                SUPPORT AGREEMENT

                MEMORANDUM OF AGREEMENT made the 31st day of July, 2004,

AMONG:

                     WASTE SERVICES, INC., a corporation existing under the laws
                     of the State of Delaware (hereinafter referred to as "WSI")

                                     - and -

                     CAPITAL ENVIRONMENTAL HOLDINGS COMPANY, an unlimited
                     liability company existing under the laws of the Province
                     of Nova Scotia (hereinafter referred to as "CAPITAL
                     HOLDINGS")

                                     - and -

                     WASTE SERVICES (CA) INC., a corporation existing under the
                     laws of the Province of Ontario (hereinafter referred to as
                     "CERI")


                WHEREAS in connection with an arrangement agreement (the
"ARRANGEMENT AGREEMENT") made June 9, 2004 among CERI, WSI and Capital Holdings,
certain holders of common shares in the capital of CERI will receive and hold
exchangeable shares in the capital of CERI (the "EXCHANGEABLE SHARES") pursuant
to the plan of arrangement (the "ARRANGEMENT") contemplated by the Arrangement
Agreement;

                AND WHEREAS, pursuant to the Arrangement Agreement, WSI, Capital
Holdings and CERI have agreed to execute a support agreement substantially in
the form of this Agreement;

                NOW THEREFORE in consideration of the respective covenants and
agreements herein contained and for other good and valuable consideration (the
receipt and sufficiency of which are hereby acknowledged), the parties hereto
covenant and agree as follows:

                                   ARTICLE 1
                         DEFINITIONS AND INTERPRETATION

1.1             DEFINED TERMS

                "AGREEMENT" means this agreement, including any Schedule or
Exhibits to this agreement, as it may be amended or supplemented from time to
time in accordance with the provisions hereof. Unless there is something in the
subject matter or context inconsistent therewith, every other capitalized term
or expression used herein and not otherwise defined herein shall have the
meaning ascribed thereto in the rights, privileges, restrictions and conditions
(collectively, the "SHARE PROVISIONS") attaching to the Exchangeable Shares as
set out in the articles of arrangement of CERI in respect of the Arrangement.


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1.2             INTERPRETATION NOT AFFECTED BY HEADINGS

                The division of this Agreement into Articles, Sections and other
portions and the insertion of headings are for convenience of reference only and
shall not affect the construction or interpretation of this Agreement. Unless
otherwise indicated, all references to an "Article" or "Section" followed by a
number or a letter refer to the specified Article or Section of this Agreement.
The terms "this Agreement", "hereof", "herein" and "hereunder" and similar
expressions refer to this Agreement and not to any particular Article, Section
or other portion hereof and include any agreement or instrument supplementary or
ancillary hereto.

1.3             DATE, NUMBER, GENDER

                If any date on which any action is required to be taken under
this Agreement is not a Business Day, such action shall be required to be taken
on the next succeeding Business Day. Words importing the singular number only
shall include the plural and vice versa. Words importing any gender shall
include all genders.

                                   ARTICLE 2
                            COVENANTS OF WSI AND CERI

2.1             COVENANTS REGARDING EXCHANGEABLE SHARES, CERI OPTIONS AND CERI
                WARRANTS

                So long as any Exchangeable Shares, CERI Options or CERI
Warrants not owned by WSI or its affiliates are outstanding, WSI will:

         (a)    not take any action that will result in the declaration or
                payment of any dividend or other distribution on the WSI Common
                Shares unless (i) CERI shall simultaneously declare or pay, as
                the case may be, a dividend or distribution economically
                equivalent thereto (as provided for in the Share Provisions) on
                the Exchangeable Shares and CERI shall have sufficient money or
                other assets or authorized but unissued securities available to
                enable the due declaration and the due and punctual payment, in
                accordance with applicable law, of any such dividend or other
                distribution on the Exchangeable Shares, and (ii) if the
                dividend or other distribution is a stock dividend or other
                distribution of stock, in lieu of such dividend CERI effects a
                corresponding and contemporaneous and economically equivalent
                (as determined in accordance with Section 2.7(d)) subdivision of
                the outstanding Exchangeable Shares and CERI shall have
                sufficient authorized but unissued securities available to
                enable the subdivision;

         (b)    advise CERI sufficiently in advance of the declaration by WSI of
                any dividend or other distribution on WSI Common Shares and take
                all such other actions as are reasonably necessary, in
                co-operation with CERI, to ensure that (i) the respective
                declaration date, record date and payment date for a dividend or
                other distribution on the Exchangeable Shares shall be the same
                as the declaration date, record date and payment date for such
                dividend or other distribution on the WSI Common Shares, and
                (ii) the record date, if any, and effective date for the
                subdivision referred to in Section 2.1(a) shall be the same as
                the record date and payment date for such dividend or other
                distribution on the WSI Common Shares;


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         (c)    ensure that the record date for any dividend or other
                distribution declared on WSI Common Shares is not less than 10
                Business Days after the declaration date of such dividend;

         (d)    take all such actions and do all such things as are reasonably
                necessary or desirable to enable and permit CERI, in accordance
                with applicable law, to pay and otherwise perform its
                obligations with respect to (i) the satisfaction of the
                Liquidation Amount, the Retraction Price or the Redemption Price
                in respect of each issued and outstanding Exchangeable Share
                (other than Exchangeable Shares owned by WSI or its affiliates)
                upon the liquidation, dissolution or winding-up of CERI or any
                other distribution of assets of CERI among its shareholders for
                the purpose of winding up its affairs, the delivery of a
                Retraction Request by a holder of Exchangeable Shares or a
                redemption of Exchangeable Shares by CERI, as the case may be,
                including without limitation all such actions and all such
                things as are necessary or desirable to enable and permit CERI
                to cause to be delivered WSI Common Shares to the holders of
                Exchangeable Shares in accordance with the provisions of Article
                5, 6 or 7, as the case may be, of the Share Provisions, and (ii)
                the CERI Options and the CERI Warrants, including without
                limitation all such actions and all such things as are necessary
                or desirable to enable or permit CERI to cause to be delivered
                WSI Common Shares to the holders of CERI Options and CERI
                Warrants upon exercise thereof in accordance with the terms
                thereunder;

         (e)    take all such actions and do all such things as are reasonably
                necessary or desirable to enable and permit Capital Holdings, in
                accordance with applicable law, to pay or otherwise perform its
                obligations arising upon the exercise by it of the Liquidation
                Call Right, the Retraction Call Right or the Redemption Call
                Right, including without limitation all such actions and all
                such things as are necessary or desirable to enable and permit
                Capital Holdings to cause to be delivered WSI Common Shares to
                the holders of Exchangeable Shares in accordance with the
                provisions of the Liquidation Call Right, the Retraction Call
                Right or the Redemption Call Right, as the case may be, and cash
                in respect of declared and unpaid dividends; and

         (f)    except in connection with any event, circumstance or action
                which causes or could cause the occurrence of a Redemption Date,
                not exercise its vote as a shareholder to initiate the voluntary
                liquidation, dissolution or winding up of CERI or any other
                distribution of the assets of CERI among its shareholders for
                the purpose of winding up its affairs, nor take any action or
                omit to take any action that is designed to result in the
                liquidation, dissolution or winding up of CERI or any other
                distribution of the assets of CERI among its shareholders for
                the purpose of winding up its affairs.

2.2             SEGREGATION OF FUNDS

                WSI will cause CERI to deposit a sufficient amount of funds in a
separate account of CERI and segregate a sufficient amount of such other assets
and property as is necessary to enable CERI to pay dividends when due and to pay
or otherwise satisfy its respective obligations under Articles 5, 6 or 7 of the
Share Provisions, as applicable.


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2.3             RESERVATION OF WSI COMMON SHARES

                WSI hereby represents, warrants and covenants in favour of CERI
and Capital Holdings that WSI has reserved for issuance and will, at all times
while any Exchangeable Shares (other than Exchangeable Shares held by WSI or its
affiliates), CERI Options or CERI Warrants are outstanding, keep available, free
from pre-emptive and other rights, out of its authorized and unissued capital
stock such number of WSI Common Shares (or other shares or securities into which
WSI Common Shares may be reclassified or changed as contemplated by Section
2.7): (a) as is equal to the sum of (i) the number of Exchangeable Shares issued
and outstanding from time to time, (ii) the number of Exchangeable Shares
issuable upon the exercise of all rights to acquire Exchangeable Shares
outstanding from time to time, and (iii) the number of WSI Common Shares
issuable upon the exercise of all CERI Options and CERI Warrants, and (b) as are
now and may hereafter be required to enable and permit WSI to meet its
obligations under the Voting and Exchange Trust Agreement and under any other
security or commitment pursuant to which WSI may now or hereafter be required to
issue WSI Common Shares, to enable and permit Capital Holdings to meet its
obligations under each of the Liquidation Call Right, the Retraction Call Right
and the Redemption Call Right and to enable and permit CERI to meet its
obligations hereunder and under the Share Provisions.

2.4             NOTIFICATION OF CERTAIN EVENTS

                In order to assist WSI to comply with its obligations hereunder
and to permit Capital Holdings to exercise the Liquidation Call Right, the
Retraction Call Right and the Redemption Call Right, CERI will notify WSI and
Capital Holdings of each of the following events at the time set forth below:

         (a)    in the event of any determination by the board of directors of
                CERI to institute voluntary liquidation, dissolution or
                winding-up proceedings with respect to CERI or to effect any
                other distribution of the assets of CERI among its shareholders
                for the purpose of winding up its affairs, at least 30 days
                prior to the proposed effective date of such liquidation,
                dissolution, winding-up or other distribution;

         (b)    promptly, upon the earlier of receipt by CERI of notice of, and
                CERI otherwise becoming aware of, any threatened or instituted
                claim, suit, petition or other proceeding with respect to the
                involuntary liquidation, dissolution or winding-up of CERI or to
                effect any other distribution of the assets of CERI among its
                shareholders for the purpose of winding up its affairs;

         (c)    immediately, upon receipt by CERI of a Retraction Request;

         (d)    on the same date on which notice of redemption is given to
                holders of Exchangeable Shares, upon the determination of a
                Redemption Date in accordance with the Share Provisions;

         (e)    as soon as practicable upon the issuance by CERI of any
                Exchangeable Shares or rights to acquire Exchangeable Shares
                (other than the issuance of Exchangeable Shares and rights to
                acquire Exchangeable Shares in exchange for outstanding common
                shares of CERI pursuant to the Arrangement); and

         (f)    at such other time and in such other manner and with respect to
                such other events as may be contemplated by the Share
                Provisions.


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2.5             DELIVERY OF WSI COMMON SHARES TO CERI AND CAPITAL HOLDINGS

                In furtherance of its obligations under Sections 2.1(d) and (e)
hereof, upon notice from CERI or Capital Holdings of any event that requires
CERI or Capital Holdings to cause to be delivered WSI Common Shares to any
holder of Exchangeable Shares, CERI Options or CERI Warrants, WSI shall
forthwith allot, issue and deliver or cause to be delivered to CERI or Capital
Holdings (unless CERI or Capital Holdings already has sufficient WSI Common
Shares) the requisite number of WSI Common Shares to be allotted to, received
by, and issued to or to the order of, the former holder of the surrendered
Exchangeable Shares, as CERI or Capital Holdings shall direct, or the holder of
the exercised CERI Option or CERI Warrant, as CERI may direct. All such WSI
Common Shares shall be duly authorized and validly issued as fully paid and
non-assessable and shall be free and clear of any lien, claim or encumbrance.

2.6             QUALIFICATION OF WSI COMMON SHARES

                If any WSI Common Shares (or other shares or securities into
which WSI Common Shares may be reclassified or changed as contemplated by
Section 2.7) to be issued and delivered hereunder require registration or
qualification with or approval of or the filing of any document, including any
prospectus or similar document or the taking of any proceeding with or the
obtaining of any order, ruling or consent from any governmental or regulatory
authority under any Canadian or United States federal, provincial, territorial
or state securities or other law or regulation or pursuant to the rules and
regulations of any securities or other regulatory authority in the United States
or Canada or the fulfillment of any other United States or Canadian legal
requirement before such shares (or such other shares or securities) may be
issued by WSI and delivered by WSI at the direction of Capital Holdings or CERI,
if applicable, to the holder of surrendered Exchangeable Shares or in order that
such shares (or such other shares or securities) may be freely traded thereafter
(other than any restrictions of general application on transfer by reason of a
holder being a "control person" for purposes of Canadian provincial securities
law or an "affiliate" of WSI for purposes of United States federal or state
securities law), WSI will in good faith expeditiously take all such actions and
do all such things as are reasonably necessary or desirable to cause such WSI
Common Shares (or such other shares or securities) to be and remain duly
registered, qualified or approved under United States and/or Canadian law, as
the case may be. WSI will in good faith expeditiously take all such actions and
do all such things as are reasonably necessary or desirable to cause all WSI
Common Shares (or such other shares or securities) to be delivered hereunder to
be listed, quoted or posted for trading on all stock exchanges and quotation
systems on which outstanding WSI Common Shares (or such other shares or
securities) have been listed by WSI and remain listed and are quoted or posted
for trading at such time.

2.7             ECONOMIC EQUIVALENCE

                So long as any Exchangeable Shares not owned by WSI or its
affiliates are outstanding:

         (a)    WSI will not without prior approval of CERI and the prior
                approval of the holders of the Exchangeable Shares given in
                accordance with section 10.2 of the Share Provisions:

                (i)     issue or distribute WSI Common Shares (or securities
                        exchangeable for or convertible into or carrying rights
                        to acquire WSI Common Shares) to the holders of all or
                        substantially all of the then outstanding WSI Common
                        Shares by way of stock dividend or other distribution,
                        other than an issue of WSI Common Shares (or securities
                        exchangeable for or convertible into or carrying rights
                        to acquire WSI Common Shares) to holders of WSI Common
                        Shares who



<PAGE>

                        exercise an option to receive dividends in WSI Common
                        Shares (or securities exchangeable for or convertible
                        into or carrying rights to acquire WSI Common Shares)
                        not issued at a discount and without financial
                        preference to the corresponding cash dividend in lieu of
                        receiving cash dividends or pursuant to any dividend
                        reinvestment plan or similar arrangement; or

                (ii)    issue or distribute rights, options or warrants to the
                        holders of all or substantially all of the then
                        outstanding WSI Common Shares entitling them to
                        subscribe for or to purchase WSI Common Shares (or
                        securities exchangeable for or convertible into or
                        carrying rights to acquire WSI Common Shares); or

                (iii)   issue or distribute to the holders of all or
                        substantially all of the then outstanding WSI Common
                        Shares (A) shares or securities of WSI of any class
                        other than WSI Common Shares (other than shares
                        convertible into or exchangeable for or carrying rights
                        to acquire WSI Common Shares, subject to Section
                        2.7(a)(i) hereof), (B) rights, options or warrants other
                        than those referred to in Section 2.7(a)(ii) above, (C)
                        evidences of indebtedness of WSI or (D) assets of WSI,

                unless the economic equivalent of such WSI Common Shares (or
                securities exchangeable for or convertible into or carrying
                rights to acquire WSI Common Shares), rights, options, warrants,
                shares, securities, evidences of indebtedness or other assets is
                issued or distributed or otherwise provided by CERI
                simultaneously to holders of the Exchangeable Shares; provided
                that, for greater certainty, the above restrictions shall not
                apply to any securities issued or distributed by WSI in order to
                give effect to and to consummate the transactions contemplated
                by, and in accordance with, the Arrangement Agreement.

         (b)    WSI will not without the prior approval of CERI and the prior
                approval of the holders of the Exchangeable Shares given in
                accordance with section 10.2 of the Share Provisions:

                (i)     subdivide, redivide or change the then outstanding WSI
                        Common Shares into a greater number of WSI Common
                        Shares;

                (ii)    reduce, combine, consolidate or change the then
                        outstanding WSI Common Shares into a lesser number of
                        WSI Common Shares; or

                (iii)   reclassify or otherwise change WSI Common Shares or
                        effect an amalgamation, merger, reorganization or other
                        transaction affecting WSI Common Shares,

                unless the same or an economically equivalent change shall
                simultaneously be made to, or in the rights of the holders of,
                the Exchangeable Shares and at least 7 days prior written notice
                thereof is given to the holders of the Exchangeable Shares.

         (c)    WSI will ensure that the record date for any event referred to
                in Sections 2.7(a) or 2.7(b) above, or (if no record date is
                applicable for such event) the effective date for any such
                event, is not less than five Business Days after the date on
                which such event is declared or announced by WSI (with
                contemporaneous notification thereof by WSI to CERI).


<PAGE>

         (d)    The board of directors of CERI shall determine, in good faith
                and in its sole discretion, economic equivalence for the
                purposes of any event referred to in Sections 2.7(a) or 2.7(b)
                above and each such determination shall be conclusive and
                binding on WSI. In making each such determination, the following
                factors shall, without excluding other factors determined by the
                board of directors of CERI to be relevant, be considered by the
                board of directors of CERI:

                (i)     in the case of any stock dividend or other distribution
                        payable in WSI Common Shares, the number of such shares
                        issued in proportion to the number of WSI Common Shares
                        previously outstanding;

                (ii)    in the case of the issuance or distribution of any
                        rights, options or warrants to subscribe for or purchase
                        WSI Common Shares (or securities exchangeable for or
                        convertible into or carrying rights to acquire WSI
                        Common Shares), the terms of such rights, options or
                        warrants and the relationship between the exercise price
                        of each such right, option or warrant and the Current
                        Market Price of a WSI Common Share;

                (iii)   in the case of the issuance or distribution of any other
                        form of property (including without limitation any
                        shares or securities of WSI of any class other than WSI
                        Common Shares, any rights, options or warrants other
                        than those referred to in Section 2.7(d)(ii) above, any
                        evidences of indebtedness of WSI or any assets of WSI),
                        the relationship between the fair market value (as
                        determined by the board of directors of CERI, acting
                        reasonably) of such property to be issued or distributed
                        with respect to each outstanding WSI Common Share and
                        the Current Market Price of a WSI Common Share; and

                (iv)    in the case of any subdivision, redivision or change of
                        the then outstanding WSI Common Shares into a greater
                        number of WSI Common Shares or the reduction,
                        combination, consolidation or change of the then
                        outstanding WSI Common Shares into a lesser number of
                        WSI Common Shares or any amalgamation, merger,
                        reorganization or other transaction affecting WSI Common
                        Shares, the effect thereof upon the then outstanding WSI
                        Common Shares.

         (e)    CERI agrees that, to the extent required, upon due notice from
                WSI, CERI will use its best efforts to take or cause to be taken
                such steps as may be necessary for the purposes of ensuring that
                appropriate dividends are paid or other distributions are made
                by CERI, or subdivisions, redivisions or changes are made to the
                Exchangeable Shares, in order to implement the required economic
                equivalent effect with respect to the WSI Common Shares and
                Exchangeable Shares as provided for in this Section 2.7.

2.8             TENDER OFFERS

                In the event that a tender offer, share exchange offer, issuer
bid, take-over bid or similar transaction with respect to WSI Common Shares (an
"OFFER") is proposed by WSI or is proposed to WSI or its shareholders and is
recommended by the board of directors of WSI, or is otherwise effected or to be
effected with the consent or approval of the board of directors of WSI, and the
Exchangeable Shares are not redeemed by CERI or purchased by Capital Holdings
pursuant to the Redemption Call Right, WSI will expeditiously and in good faith
take all such actions and do all such things as are necessary or



<PAGE>

desirable to enable and permit holders of Exchangeable Shares (other than WSI
and its affiliates) to participate in such Offer to the same extent and on an
economically equivalent basis as the holders of WSI Common Shares, without
discrimination. Without limiting the generality of the foregoing, WSI will
expeditiously and in good faith take all such actions and do all such things as
are reasonably necessary or desirable to ensure that holders of Exchangeable
Shares may participate in each such Offer without being required to retract
Exchangeable Shares as against CERI (or, if so required, to ensure that any such
retraction, shall be effective only upon, and shall be conditional upon, the
closing of such Offer and only to the extent necessary to tender or deposit to
the Offer). Nothing herein shall affect the rights of CERI to redeem (or Capital
Holdings to purchase pursuant to the Redemption Call Right) Exchangeable Shares,
as applicable, in the event of a WSI Control Transaction.

2.9             OWNERSHIP OF OUTSTANDING SHARES

                Without the prior approval of CERI and the prior approval of the
holders of the Exchangeable Shares given in accordance with section 10.2 of the
Share Provisions, WSI covenants and agrees in favour of CERI that, as long as
any outstanding Exchangeable Shares are owned by any Person other than WSI or
any of its affiliates, WSI will be, and remain, the direct or indirect
beneficial owner of all issued and outstanding CERI Common Shares and all of the
issued and outstanding shares in the capital of Capital Holdings.

2.10            WSI AND AFFILIATES NOT TO VOTE EXCHANGEABLE SHARES

                WSI covenants and agrees that it will appoint and cause to be
appointed proxyholders with respect to all Exchangeable Shares held by it and
its affiliates for the sole purpose of attending each meeting of holders of
Exchangeable Shares in order to be counted as part of the quorum for each such
meeting. WSI further covenants and agrees that it will not, and will cause its
affiliates not to, exercise any voting rights which may be exercisable by
holders of Exchangeable Shares from time to time pursuant to the Share
Provisions or pursuant to the provisions of the OBCA (or any successor or other
corporate statute by which CERI may in the future be governed) with respect to
any Exchangeable Shares held by it or by its affiliates in respect of any matter
considered at any meeting of holders of Exchangeable Shares.

2.11            RULE 10B-18 PURCHASES

                For certainty, nothing contained in this Agreement, including
without limitation the obligations of WSI contained in Section 2.8 hereof, shall
limit the ability of WSI or CERI to make a "Rule 10b-18 Purchase" of WSI Common
Shares pursuant to Rule 10b-18 of the United States Securities Exchange Act of
1934, as amended, or any successor provision thereof.

                                   ARTICLE 3
                                 WSI SUCCESSORS

3.1             CERTAIN REQUIREMENTS IN RESPECT OF COMBINATION, ETC.

                WSI shall not consummate any transaction (whether by way of
reconstruction, reorganization, consolidation, merger, transfer, sale, lease or
otherwise) whereby all or substantially all of its undertaking, property and
assets would become the property of any other Person or, in the case of a
merger, of the continuing corporation resulting therefrom unless:

         (a)    such other Person or continuing corporation (the "WSI
                SUCCESSOR") by operation of law, becomes, without more, bound by
                the terms and provisions of this Agreement or, if not so



<PAGE>

                bound, executes, prior to or contemporaneously with the
                consummation of such transaction, an agreement supplemental
                hereto and such other instruments (if any) as are reasonably
                necessary or advisable to evidence the assumption by the WSI
                Successor of liability for all moneys payable and property
                deliverable hereunder and the covenant of such WSI Successor to
                pay and deliver or cause to be delivered the same and its
                agreement to observe and perform all the covenants and
                obligations of WSI under this Agreement;

         (b)    in the event that WSI Common Shares are reclassified or
                otherwise changed as part of such transaction, the same or an
                economically equivalent change is simultaneously made to, or in
                the rights of the holders of, the Exchangeable Shares; and

         (c)    such transaction shall be upon such terms and conditions as to
                substantially preserve and not impair in any material respect
                any of the rights, duties, powers and authorities of the other
                parties hereunder or the holders of Exchangeable Shares.

3.2             VESTING OF POWERS IN SUCCESSOR

                Whenever the conditions of Section 3.1 have been duly observed
and performed, the parties, if required by Section 3.1, shall execute and
deliver the supplemental agreement provided for in Section 3.1(a) and thereupon
the WSI Successor shall possess and from time to time may exercise each and
every right and power of WSI under this Agreement in the name of WSI or
otherwise and any act or proceeding by any provision of this Agreement required
to be done or performed by the board of directors of WSI or any officers of WSI
may be done and performed with like force and effect by the directors or
officers of such WSI Successor.

3.3             WHOLLY-OWNED SUBSIDIARIES

                Nothing herein shall be construed as preventing (i) the
amalgamation or merger of any wholly-owned direct or indirect subsidiary of WSI
with or into WSI, (ii) the winding-up, liquidation or dissolution of any
wholly-owned subsidiary of WSI, provided that all of the assets of such
subsidiary are transferred to WSI or another wholly-owned direct or indirect
subsidiary of WSI or (iii) any other distribution of the assets of any
wholly-owned direct or indirect subsidiary of WSI among the shareholders of such
subsidiary for the purpose of winding up its affairs and any such transactions
are expressly permitted by this Article 3.

                                   ARTICLE 4
                                     GENERAL

4.1             TERM

                This Agreement shall come into force and be effective as of the
date hereof and shall terminate and be of no further force and effect at such
time as no Exchangeable Shares (or securities or rights convertible into or
exchangeable for or carrying rights to acquire Exchangeable Shares) are held by
any Person other than WSI and any of its affiliates.

4.2             CHANGES IN CAPITAL OF WSI AND CERI

                At all times after the occurrence of any event contemplated
pursuant to Sections 2.7 and 2.8 hereof or otherwise, as a result of which
either WSI Common Shares or the Exchangeable Shares or



<PAGE>

both are in any way changed, this Agreement shall forthwith be amended and
modified as necessary in order that it shall apply with full force and effect,
mutatis mutandis, to all new securities into which WSI Common Shares or the
Exchangeable Shares or both are so changed and the parties hereto shall execute
and deliver an agreement in writing giving effect to and evidencing such
necessary amendments and modifications.

4.3             SEVERABILITY

                If any provision of this Agreement is held to be invalid,
illegal or unenforceable, the validity, legality or enforceability of the
remainder of this Agreement shall not in any way be affected or impaired thereby
and this Agreement shall be carried out as nearly as possible in accordance with
its original terms and conditions.

4.4             AMENDMENTS, MODIFICATIONS

                Subject to Sections 4.2, 4.3 and 4.5, this Agreement may not be
amended or modified except by an agreement in writing executed by CERI, Capital
Holdings and WSI and approved by the holders of the Exchangeable Shares in
accordance with section 10.2 of the Share Provisions.

4.5             MINISTERIAL AMENDMENTS

                Notwithstanding the provisions of Section 4.4, the parties to
this Agreement may in writing at any time and from time to time, without the
approval of the holders of the Exchangeable Shares, amend or modify this
Agreement for the purposes of:

         (a)    adding to the covenants of any or all parties, provided that the
                board of directors of each of CERI, Capital Holdings and WSI
                shall be of the good faith opinion that such additions will not
                be prejudicial to the rights or interests of the holders of the
                Exchangeable Shares;

         (b)    making such amendments or modifications not inconsistent with
                this Agreement as may be necessary or desirable with respect to
                matters or questions which, in the good faith opinion of the
                board of directors of each of CERI, Capital Holdings and WSI, it
                may be expedient to make, provided that each such board of
                directors shall be of the good faith opinion that such
                amendments or modifications will not be prejudicial to the
                rights or interests of the holders of the Exchangeable Shares;
                or

         (c)    making such changes or corrections which, on the advice of
                counsel to CERI, Capital Holdings and WSI, are required for the
                purpose of curing or correcting any ambiguity or defect or
                inconsistent provision or clerical omission or mistake or
                manifest error, provided that the boards of directors of each of
                CERI, Capital Holdings and WSI shall be of the good faith
                opinion that such changes or corrections will not be prejudicial
                to the rights or interests of the holders of the Exchangeable
                Shares.

4.6             MEETING TO CONSIDER AMENDMENTS

                CERI, at the request of WSI, shall call a meeting or meetings of
the holders of the Exchangeable Shares for the purpose of considering any
proposed amendment or modification requiring approval pursuant to Section 4.4
hereof. Any such meeting or meetings shall be called and held in accordance with
the articles and by-laws of CERI, the Share Provisions and all applicable laws.


<PAGE>

4.7             AMENDMENTS ONLY IN WRITING

                No amendment to or modification or waiver of any of the
provisions of this Agreement otherwise permitted hereunder shall be effective
unless made in writing and signed by all of the parties hereto.

4.8             ENUREMENT

                This Agreement shall be binding upon and enure to the benefit of
the parties hereto and their respective successors and permitted assigns. No
party may assign or transfer all or any part of its rights and obligations under
this Agreement without the prior written consent of the other parties hereto and
the consent of the holders of Exchangeable Shares given in accordance with
section 10.2 of the Share Provisions.

4.9             NOTICES TO PARTIES

                All notices and other communications required or permitted to be
given pursuant to any provision of this Agreement shall be given or made in
writing and shall be deemed to be validly given if served personally, including
by prepaid courier delivery, or by telecopy, in each case addressed to the
particular party at:

                in the case of each of WSI, Capital Holdings and CERI:

                Waste Services (CA) Inc.
                1122 International Blvd
                Suite 601
                Burlington, Ontario
                L7L 6Z8

                Attention:        General Counsel
                Fax No.:          (905) 319-9408

or at such other address of which any party may, from time to time, advise the
other parties by notice in writing given in accordance with the foregoing. Any
notice or other communication given personally shall be deemed to have been
given and received upon delivery thereof and if given by telecopy shall be
deemed to have been given and received on the date of receipt thereof, unless
such day is not a Business Day or unless such delivery occurs after 5:00 p.m.
(local time), in which case it shall be deemed to have been given and received
on the immediately following Business Day.

4.10            JURISDICTION

                This Agreement shall be construed and enforced in accordance
with the laws of the Province of Ontario and the laws of Canada applicable
therein.

4.11            ATTORNMENT

                Each of the parties hereto agrees that any action or proceeding
arising out of or relating to this Agreement may be instituted in the courts of
Ontario, waives any objection which it may have now or hereafter to the venue of
any such action or proceeding, irrevocably submits to the jurisdiction of the
said courts in any such action or proceeding, agrees to be bound by any judgment
of the said courts and not to seek, and hereby waives, any review of the merits
of any such judgment by the courts of any other

<PAGE>

jurisdiction and WSI hereby appoints CERI at its registered office in the
Province of Ontario as attorney for service of process.




<PAGE>

4.12            COUNTERPARTS

                This Agreement may be executed in counterparts, each of which
shall be deemed an original, and all of which taken together shall constitute
one and the same instrument.

                IN WITNESS WHEREOF, the parties hereto have caused this
Agreement to be duly executed as of the date first above written.


                                   WASTE SERVICES, INC.


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


                                   CAPITAL ENVIRONMENTAL HOLDINGS COMPANY


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


                                   WASTE SERVICES (CA) INC.


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