UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                   FORM 10-Q/A
                                (Amendment No. 1)

(Mark One)

[ X ]    QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                  For the quarterly period ended June 30, 1998

                                       OR

[    ]   TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                         Commission file number 0-16225

                                      EMCON

             (Exact name of Registrant as specified in its charter)


             California                                        94-1738964
 ----------------------------------                       ----------------------
(State or other jurisdiction of                             (I.R.S. Employer
incorporation or organization)                               Identification No.)

400 South El Camino Real, Suite 1200
San Mateo, California
                                                                 94402
----------------------------------------------                ------------
(Address of  principal executive offices)                      (Zip Code)


       Registrant's telephone number, including area code: (650) 375-1522

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12 months (or for such  shorter  period that the  registrant  was
required  to file  such  reports),  and  (2) has  been  subject  to such  filing
requirements for the past 90 days. Yes [ X ] No [ ]

8,723,100 shares of Common Stock Issued and Outstanding as of July 27, 1998.



<PAGE>



                    INFORMATION TO BE INCLUDED IN THE REPORT
                                 Amendment No. 1

        The undersigned registrant hereby amends the following items of its Form
10-Q for the period ended June 30, 1998:  Form 10Q filed with the Securities and
Exchange Commission on August 5, 1998. The Consolidated  Statements of Income on
page 4 and the Earnings Per Share on page 8 for the quarter  ended June 30, 1998
have been amended due to a calculation error for weighted shares outstanding for
1998.  The  recalculation  did not  affect  earnings  per share  during the 1998
periods stated except for diluted  earnings per share for the quarter ended June
30, 1998. The revised  calculations  changes diluted earnings per share to $0.06
from the previously reported $0.07.
<TABLE>
<CAPTION>
EMCON
CONSOLIDATED STATEMENTS OF INCOME
-------------------------------------------------------------------------------------------------------------------------
                                                                   Three months ended              Six months ended
                                                                        June 30,                       June 30,
                                                                      (Unaudited)                     (Unaudited)
                                                               ---------------------------     --------------------------
(In thousands, except per share amounts)                             1998          1997             1998          1997
-------------------------------------------------------------------------------------------------------------------------
<S>                                                                 <C>           <C>               <C>          <C>

Gross revenue                                                       $40,985       $33,114           $69,764      $64,477
Outside services at cost                                              4,776         8,647             7,733       12,429
                                                                    -------       -------           -------      -------

         Net revenue                                                 36,209        24,467            62,031       52,048

Costs and expenses:
     Direct expenses                                                 21,979        12,206            35,801       24,812
     Indirect expenses                                               13,040        11,177            24,897       25,403
     Restructuring/other charges                                         --            --                --          (75)
     Loss on disposition of laboratory                                   --            --                --          333
     Gain on sale of assets                                              --            --                           (826)
                                                                    -------       -------           -------      -------
                                                                                                         --

         Income from operations                                       1,190         1,084             1,333        2,401

Interest income                                                        (151)         (125)             (319)        (219)
Interest expense                                                        304           317               597          648
Equity in earnings of affiliates                                         --           (16)              (15)         (34)
Minority interest (income) expense                                        2           148                            183
                                                                    -------       -------           -------      -------
                                                                                                        (20)

Income before provision for income taxes                              1,035           760             1,090        1,823
Provision for income taxes                                              461           266               496          638
                                                                    -------       -------           -------      -------

Net income                                                          $   574       $   494           $   594      $ 1,185
                                                                    =======       =======           =======      =======

Basic earnings per share                                            $  0.07       $  0.06           $  0.07      $  0.14
                                                                    =======       =======           =======      =======

Diluted earnings per share                                          $  0.06       $  0.06           $  0.07      $  0.14
                                                                    =======       =======           =======      =======

Shares used in computing basic earnings per share                     8,712         8,534             8,643        8,534
                                                                    =======       =======           =======      =======

Shares used in computing diluted earnings per share                   8,924         8,554             8,876        8,545
                                                                    =======       =======           =======      =======
See accompanying notes.
</TABLE>


<PAGE>

<TABLE>
<CAPTION>

6.  Earnings Per Share

                                                                 Three months ended               Six months ended
                                                                       June 30                         June 30
                                                           -----------------------------    ------------------------------
    (In thousands, except for earnings per share)                1998             1997            1998         1997
    ----------------------------------------------------------------------------------------------------------------------
    <S>                                                         <C>              <C>             <C>           <C>
    Numerator:
     Net income                                                 $  574           $  494         $  594         $1,185
                                                                ------           ------         ------         ------
     Numerator for basic earnings per share -
         income available to common stockholders                   574              494            594          1,185
     Effect of dilutive securities:
         8% convertible debentures                              N/A(1)           N/A(1)         N/A(1)          N/A(1)
                                                                ------           ------         ------          ------
     Numerator for diluted earnings per share -
         income available to common stockholders
         after assumed conversions                              $  574           $  494        $  594           $1,185
                                                                ======           ======        ======           ======
    Denominator:
    Denominator for basic earnings per share -
         weighted-average shares                                 8,712            8,534         8,643            8,534
    Effect of dilutive securities:
         Employee stock options                                    212               20           233               11
         8% convertible debentures                              N/A(1)           N/A(1)         N/A(1)           N/A(1)
    Dilutive potential common shares
    Denominator for diluted earnings per share -
         adjusted weighted average shares and assumed
         conversions                                             8,924            8,554         8,876            8,545
                                                                ======           ======        ======           ======
    Basic earnings per share                                    $ 0.07           $ 0.06        $ 0.07           $ 0.14
                                                                ======           ======        ======           ======
    Diluted earnings per share                                  $ 0.06           $ 0.06        $ 0.07           $ 0.14
                                                                ======           ======        ======           ======
    ------------------------------------------------------ --------------- ---------------- -------------- ---------------
  (1)Excluded from the above  reconciliations were approximately  269,000 shares
  of common stock that may be issued at $6.50 per share to convert $1,747,000 of
  indebtedness  to certain  senior  management  of OWT because  such shares were
  antidilutive  at June 30, 1998.  Conversion  of debt,  if it occurs,  would be
  within  ninety days after  November 30,  2001.  Also  excluded  from the above
  reconciliations were approximately  123,000 shares of common stock that may be
  issued at $6.50 per share to  convert  $800,000  of  indebtedness  to  certain
  senior  management  of NEP because such shares were  antidilutive  at June 30,
  1998.  Conversion of debt, if it occurs,  would be 50% at May 1, 2000, and 50%
  at May 1, 2002.

</TABLE>

<PAGE>



                                   SIGNATURES

Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.



Date:  August 21, 1998                     EMCON


                                           \s\  R. Michael Momboisse
                                           -------------------------------------
                                           R. MICHAEL MOMBOISSE
                                           Chief Financial Officer,
                                           Vice President - Legal, and Secretary
                                           (Duly authorized and principal
                                            financial and accounting officer)