EXHIBIT 3.71
                                   RESTATED
                           ARTICLES OF INCORPORATION
                                      OF
                                     EMCON





          The undersigned certify that:

          1.  They are the President and the Secretary, respectively, of EMCON a
     California corporation (this "Corporation").

          2.  The Articles of Incorporation of this Corporation, as amended or
     amended and restated to the date of the filing of this Certificate, are
     amended and restated to read in full as follows:

                                   Article I
                                   ---------

          The name of this Corporation is:  EMCON.

                                   Article II
                                   ----------

          The purpose of this Corporation is to engage in any lawful act or
     activity for which a corporation may be organized under the General
     Corporation Law of California other than the banking business, the trust
     company business or the practice of a profession permitted to be
     incorporated by the California Corporations Code.

                                  Article III
                                  -----------

          This Corporation is authorized to issue only one class of shares of
     stock; and the total number of shares which this Corporation is authorized
     to issue is one thousand (1,000).

                                   Article IV
                                   ----------

          The liability of the directors of this Corporation for monetary
     damages shall be eliminated to the fullest extent permissible under
     California law.

                                   Article V
                                   ---------


          This Corporation is authorized to provide indemnification of its
     agents (as such term is defined in Section 317 of the California General
     Corporation Law) to the fullest extent permissible under California law.

          3.  The foregoing amendment and restatement of Articles of
     Incorporation has been duly approved by the board of directors of this
     Corporation.

          4.  The foregoing amendment and restatement of Articles of
     Incorporation has been duly approved by the required vote of shareholders
     of this Corporation in accordance with Section 902 of the California
     Corporations Code.  The total number of outstanding shares of this
     Corporation is one hundred (100).  The number of shares voting in favor of
     the amendment equaled or exceeded the vote required.  The percentage vote
     required was more than 50%.

          We further declare under penalty of perjury under the laws of the
     State of California that the matters set forth in this certificate are true
     and correct of our own knowledge.


     Dated: June 21, 1999
                            /s/ James G. Kirk
                            ----------------------------------
                            James G. Kirk, Chief Executive Officer and President

                            /s/ James M. Redwine
                            ---------------------------------
                            James M. Redwine, Secretary


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