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                                                                   EXHIBIT 10.30



                   THIRD AMENDMENT TO EMPLOYMENT AGREEMENT

         This Third Amendment to Employment Agreement (the "Amendment") is made
and entered into as of this 11th day of November, 1996, by and between
Allwaste, Inc., a Delaware corporation (the "Company"), and Robert M. Chiste
(the "Employee").

         WHEREAS, the Company and the Employee are parties to an Employment
Agreement dated October 17, 1994 (the "Agreement") which is attached hereto as
Addendum 1 and is incorporated herein in its entirety by reference, pursuant to
which the Employee has performed certain services to the Company; and

         WHEREAS, the Company and the Employee amended the Agreement pursuant
to that certain First Amendment to Employment Agreement dated October 26, 1995
(the "First Amendment") and that certain Second Amendment to Employment
Agreement dated October 25, 1996 (the "Second Amendment"); and

         WHEREAS, the Company and the Employee desire to further amend the
Agreement as provided herein.

         NOW, THEREFORE, for and in consideration of the mutual covenants and
promises and representations contained herein, and other good and valuable
consideration, the receipt and sufficiency of which are acknowledged herein,
the Company and the Employee agree as follows:

1.       Subparagraph 1(a) of the Agreement is hereby amended by deleting the
subparagraph in its entirety and substituting the following in replacement
thereof:

                          (a)     EMPLOYMENT.  The Company hereby employs
                 Employee as its President and Chief Executive Officer.  The
                 Board of Directors may request that the Employee serve in
                 various capacities for the Company's subsidiaries; however, in
                 connection with such service, the Employee shall not be
                 requested to undertake duties and responsibilities that are
                 substantially different than those assigned to the Employee as
                 a result of his primary position with the Company or that are
                 unreasonable (or inconsistent with those given to
                 similarly-situated employees) considering the skills and
                 expertise of the Employee and the condition of the Company.
                 The Employee hereby accepts this employment under the terms
                 and provisions herein contained and agrees to devote his full
                 time, attention and efforts to promote and further the
                 business and services of the Company.  The Employee shall
                 faithfully adhere to, execute and fulfill all policies
                 (written and unwritten) established by the Company.

2.       Section 2(a) of the Agreement is hereby amended by deleting the
subparagraph in its entirety and substituting the following in replacement
thereof:

                 (a)      BASE SALARY.  The base salary payable to the Employee
                 under this Agreement shall be $325,000 per year, payable in
                 equal bi-weekly installments or



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                 on any other periodic basis consistent with the Company's
                 payroll procedures, which amount may be increased from time to
                 time.

3.       Subparagraph 2(b)(iv) of the Agreement is hereby amended by deleting
the subparagraph in its entirety and substituting the following in replacement
thereof:

                          (iv)    The Employee shall be eligible to participate
                 in the Company's incentive bonus plan, deferred compensation
                 plan, and supplementary executive retirement plan, as each may
                 be in effect from time to time.

4.       Section 6 of the Agreement is hereby amended by deleting the
subparagraph in its entirety and substituting the following in replacement
thereof:

                 6.       TERM; TERMINATION; COMPENSATION AND OTHER RIGHTS ON
         TERMINATION.

                 The term of this Agreement shall begin on the date of this
         Agreement and, unless terminated as herein provided, continue for a
         term of five (5) years and thereafter on a year-to-year basis on the
         same terms and conditions contained herein.

                 (a)      TERMINATION AS A RESULT OF THE EMPLOYEE'S DEATH.
                                  
                                  (1)  This Agreement will terminate
                          automatically on the death of the Employee.

                                  (2)  Compensation and Benefits. The Company
                          shall pay to the Employee's beneficiary an amount
                          equal to accrued compensation owing to the Employee
                          on the date of his death (including, without
                          limitation, salary, pro rata bonus (if any and
                          subject to the terms and conditions of any applicable
                          bonus or incentive compensation plans), deferred
                          compensation and accrued vacation pay), together with
                          applicable death benefits, if any.  In accordance
                          with the Company's Amended and Restated 1989
                          Replacement Non-Qualified Stock Option Plan (as the
                          same may be amended from time to time, the "Option
                          Plan"), the Employee's beneficiary shall be entitled
                          to exercise all exercisable stock options held by the
                          Employee as of the date of death until the earlier of
                          (i) the one-year period following the date of death
                          or (ii) the date the option would otherwise expire.

                 (b)      TERMINATION BY THE COMPANY ON ACCOUNT OF DISABILITY.

                                  (1)  If, as a result of the Employee's
                          inability to perform his duties under this Agreement
                          (with or without reasonable accomodation) because of
                          illness, physical or mental disability, or other
                          incapacity which continues for





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                          an uninterrupted period in excess of three (3) months
                          or a cumulative period of six (6) months in any
                          twelve (12) month period, and if, within thirty (30)
                          days after the Company has given the Employee written
                          notice of the Company's intention to terminate the
                          Employee's employment hereunder as a result of such
                          incapacity, the Employee shall not have returned to
                          the full-time performance of his duties hereunder,
                          then the Company may thereafter terminate the
                          Employee's employment on account of "DISABILITY";
                          provided, however, such termination shall not by
                          itself alter or impair the Employee's rights as a
                          "disabled employee" or otherwise under any of the
                          Company's employee benefit plans.

                                  (2)  Compensation and Benefits.  The Company
                          shall pay to the Employee an amount equal to accrued
                          compensation owing to the Employee as of the date of
                          termination (including, without limitation, salary,
                          pro rata bonus (if any and subject to the terms and
                          conditions of any applicable bonus or incentive
                          compensation plans), deferred compensation and
                          accrued vacation pay).  Subject to approval by the
                          Compensation Committee, the Company shall cause all
                          stock options held by the Employee to be regranted
                          under the Company's 1992 Limited Non-Qualified Stock
                          Option Plan (the "1992 Plan") so that such options
                          continue to vest and remain exercisable for a period
                          of twelve months following the date of termination.
                          Whenever compensation is payable to the Employee
                          hereunder during a period in which he is partially or
                          totally disabled, and such Disability would (except
                          for the provisions hereof) entitle the Employee to
                          Disability income or salary continuation payments
                          from the Company according to the terms of any plan
                          or program presently maintained or hereafter
                          established by the Company, the Disability income or
                          salary continuation paid to the Employee pursuant to
                          any such plan or program shall be considered a
                          portion of the payment to be made to the Employee
                          pursuant to this Section 7(b)(2) and shall not be in
                          addition hereto.  If Disability income is payable
                          directly to the Employee by an insurance company
                          under the terms of an insurance policy paid for by
                          the Company, the amounts paid to the Employee by such
                          insurance company shall be considered a portion of
                          the payment to be made to the Employee pursuant to
                          this Section 7(b)(2) and shall not be in addition
                          hereto.

                 (c)      TERMINATION BY THE COMPANY FOR CAUSE.

                                  (1)  The Company may at any time during the
                          term of this Agreement, in its sole discretion,
                          terminate the Employee's employment with the Company
                          for "Cause."  For purposes of this Agreement, the
                          following shall constitute "CAUSE": (1) the Employee
                          willfully and continually fails to perform
                          substantially the Employee's duties with the Company
                          (other than any such





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                          failure resulting from the Employee's incapacity due
                          to physical or mental illness), which failure
                          continues unabated after a written demand for
                          substantial performance is delivered to the Employee
                          by the President or the Chairman of the Board that
                          specifically identifies the manner in which the
                          President or the Board believes that the Employee has
                          not substantially performed the Employee's duties;
                          (2) the Employee willfully engages in gross
                          misconduct that is materially and demonstrably
                          injurious to the Company; or (3) the Employee is
                          convicted of a felony crime by a court of competent
                          jurisdiction.

                                  For purposes of this Section 6(c), an act or
                          failure to act on the Employee's part shall be
                          considered "willful" if done or omitted to be done by
                          the Employee otherwise than in good faith and without
                          reasonable belief that the Employee's action or
                          omission was in the best interest of the Company.
                          Notwithstanding the foregoing, the Employee shall not
                          be deemed to have been terminated by the Company for
                          Cause unless and until the Company shall have
                          delivered to the Employee a copy of a resolution duly
                          adopted by the affirmative vote of not less than a
                          majority of the entire membership of the Board, at a
                          meeting of the Board called and held for the purpose
                          (after reasonable notice to the Employee and an
                          opportunity for the Employee, together with the
                          Employee's counsel, to be heard before the Board),
                          finding that, in the good faith opinion of the Board,
                          the Employee was guilty of conduct set forth in
                          clauses (a) or (b) of the second sentence of this
                          Section 7(c) and specifying the particulars thereof
                          in reasonable detail.

                                  (2)  Compensation and Benefits. The Company
                          shall pay to the Employee an amount equal to accrued
                          compensation owing to the Employee as of the date of
                          termination (including, salary and accrued vacation
                          pay).  In accordance with the Company's Option Plan,
                          the Employee shall be entitled to exercise all
                          exercisable stock options held by the Employee as of
                          the date of termination until the expiration of the
                          three-month period following such date of
                          termination.

                 (d)      TERMINATION BY THE EMPLOYEE.

                                  (1)  At any time after the execution of this
                          Agreement, the Employee may elect to terminate this
                          Agreement and the Employee's employment hereunder.

                                  (2)  Compensation and Benefits.  In the event
                          the Employee terminates this Agreement for any
                          reason, the Employee shall be entitled to receive an
                          amount equal to accrued compensation owing to the
                          Employee as of the date of termination (including,
                          without limitation, salary, pro rata





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                          bonus (if any and subject to the terms and conditions
                          of any applicable bonus or incentive compensation
                          plans), deferred compensation and accrued vacation
                          pay).  In accordance with the Company's Option Plan,
                          the Employee shall be entitled to exercise all
                          exercisable stock options held by the Employee as of
                          the date of termination until the expiration of the
                          three-month period following such date of
                          termination.

                 (e)      TERMINATION BY THE COMPANY FOR OTHER THAN CAUSE.

                                  (1)      At any time after the execution of
                          this Agreement, the Company may, without Cause, elect
                          to terminate this Agreement and the Employee's
                          employment hereunder.

                                  (2)      Compensation and Benefits.  In the
                          event the Company elects to terminate this Agreement
                          pursuant to this Section 7(e), the Employee shall be
                          entitled to receive his monthly base salary for 24
                          months (the "Severance Period"), payable in
                          accordance with the Company's customary payroll
                          procedures, as severance.  In addition, the Company
                          shall pay to the Employee an amount equal to accrued
                          compensation owing to the Employee as of the date of
                          termination (including, without limitation, salary,
                          pro rata bonus (if any and subject to the terms and
                          conditions of any applicable bonus or incentive
                          compensation plans), deferred compensation and
                          accrued vacation pay).  Subject to the approval of
                          the Compensation Committee, the Company shall cause
                          all stock options held by the Employee to be
                          regranted under the Company's 1992 Plan so that such
                          options continue to vest in accordance with the terms
                          of the original grants during the Severance Period
                          and shall remain exercisable until three months
                          following the earlier of the date of final vesting of
                          any such option grant or the final date of the
                          Severance Period.  The Company shall also pay to the
                          Employee an amount equal to (a) the amount of of the
                          monthly premium payment to continue coverage for the
                          Employee and the Employee's eligible dependents under
                          the Company's health insurance plan under COBRA,
                          multiplied by (b) 24 months.  Further, the Employee
                          shall be credited with an additional 24 months of
                          service credit under the Company's Supplemental
                          Executive Retirement Plan.

                 (f)      SURVIVING OBLIGATIONS FOLLOWING TERMINATION.

                                  (1)      In the event of termination of this
                          Agreement for any reason provided in this Section 6
                          herein or if Employee resigns prior to the expiration
                          of the term of this Agreement, all rights and
                          obligations of the Company and the Employee under
                          this Agreement shall cease immediately, except that
                          Employee's obligations under Sections 3, 4, 5 and 7
                          herein shall survive such





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                          termination, and except as otherwise provided in this
                          Section 6, the Employee shall thereafter have no
                          right to receive any compensation hereunder.

5.       This Amendment shall be governed by and construed in accordance with
the laws of the State of Texas.

6.       The Agreement, as amended by the First Amendment and this Amendment,
supersedes any and all other agreements, either oral or in writing, between
Company and the Employee with respect to the employment of the Employee by the
Company and contains all of the representations, covenants and agreements
between the Company and the Employee with respect to such employment.  The
Agreement, as amended, may not be later modified except by a further writing
signed by the Company and the Employee, and no term of this Agreement may be
waived except by writing signed by the party waiving the benefit of such term.

7.       Except as modified by this Amendment, all other terms of the Agreement
shall continue in full force and effect without modification.

         IN WITNESS WHEREOF, the parties have executed this Third Amendment to
Employment Agreement in duplicate originals, effective as of November 11, 1996.

                     ALLWASTE, INC.
                     
                     
                     By:     /s/ William L. Fiedler                       
                        ---------------------------------------------------
                             William L. Fiedler
                             Vice President, General Counsel, Secretary and
                             Corporate Compliance Officer
                     
                     
                     ROBERT M. CHISTE
                     
                     
                             /s/ Robert M. Chiste                         
                     ------------------------------------------------------
                     Robert M. Chiste
                     
                     
                           


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