EXHIBIT 5
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                              OPINION RE LEGALITY



























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GRAY CARY WARE
   FREIDENRICH
   A PROFESSIONAL CORPORATION


Attorneys at Law
400 Hamilton Avenue 
Palo Alto, CA 94301-1825
Tel (415) 328-6561
Fax (415) 327-3699

                                                                   Our File No.
                                 July 26, 1995                    1050224-901802


                              





Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C.  20549

     Re:  EMCON Registration  Statement on Form S-8 Registering  Shares Issuable
          Under the Employee Stock Purchase Plan 

Ladies and Gentlemen:

          As legal counsel for EMCON, a California  corporation (the "Company"),
we are rendering  this opinion in  connection  with the  registration  under the
Securities Act of 1933, as amended,  of up to 350,000 shares of the Common Stock
of the Company which may be issued  pursuant to the exercise of purchase  rights
granted under the EMCON Employee Stock Purchase Plan (the "Plan").

          We have  examined  all  instruments,  documents  and records  which we
deemed  relevant  and  necessary  for  the  basis  of  our  opinion  hereinafter
expressed.  In  such  examination,  we  have  assumed  the  genuineness  of  all
signatures and the  authenticity  of all documents  submitted to us as originals
and the conformity to the originals of all documents submitted to us as copies.
                  
          We are  admitted to practice  only in the State of  California  and we
express  no  opinion  concerning  any law  other  than  the law of the  State of
California and the federal law of the United States.



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Securities and Exchange Commission
Page 2


          Based on such  examination,  we are of the  opinion  that the  350,000
shares of Common  Stock  which may be issued upon  exercise  of purchase  rights
granted under the Plan are duly authorized shares of the Company's Common Stock,
and, when issued  against  payment of the purchase  price therefor in accordance
with  the  provisions  of the  Plan,  will be  validly  issued,  fully  paid and
non-assessable.

          We hereby  consent to the filing of this  opinion as an exhibit to the
Registration  Statement  referred  to above and the use of our name  wherever it
appears in said Registration Statement.
                                                          

                                        Respectfully submitted,
               

                                        GRAY CARY WARE & FREIDENRICH
                                        A Professional Corporation













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