UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                    FORM 10-Q

(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.

                                       1
<PAGE>



                                      EMCON
                                      INDEX
                               REPORT ON FORM 10-Q
                       FOR THE QUARTER ENDED JUNE 30, 1998



                                                                        Page
                                                                       Number
                                                                      -------
FACING SHEET...........................................................   1

TABLE OF CONTENTS......................................................   2

PART I.   FINANCIAL INFORMATION

          Item 1.     Financial Statements

                      Consolidated Balance Sheets -
                      June 30, 1998 and December 31, 1997..............   3

                      Consolidated Statements of Income -
                      Three and six months ended
                      June 30, 1998 and 1997...........................   4

                      Consolidated Statements of Cash Flows -
                      Six months ended June 30, 1998 and 1997..........   5

                      Notes to Consolidated Financial Statements.......   6

        Item 2.       Management's Discussion and Analysis of
                      Financial Condition and Results of
                      Operations.......................................  12

PART II.   OTHER INFORMATION...........................................  16

Signatures.............................................................  17

Index to Exhibits......................................................  18

                                       2

<PAGE>
<TABLE>
<CAPTION>



   EMCON
   CONSOLIDATED BALANCE SHEETS
 ----------------------------------------------------------------------------------- ---------------- ----------------
                                                                                        June 30,       December 31,
                                                                                          1998             1997
 (In thousands, except share amounts)                                                  (Unaudited)       (Audited)
 ----------------------------------------------------------------------------------- ---------------- ----------------
<S>                                                                                 <C>                <C>

ASSETS
 Current Assets:
 Cash and cash equivalents                                                           $   2,356         $  6,106
 Accounts Receivable:
     Billed accounts receivable, net of allowance for doubtful accounts
       of $708 and $634 at June 30, 1998 and December 31, 1997, respectively            37,552           31,413
     Unbilled accounts receivable, net of allowance for doubtful accounts
       of $333 and $295 at June 30, 1998 and December 31, 1997, respectively             7,203            5,310
 Costs and estimated earnings in excess of billings on
     uncompleted contracts                                                               1,526              678
 Prepaid expenses and other current assets                                               3,703            3,401
 Inventory                                                                               2,698            2,238
 Deferred taxes, current portion                                                         3,235            4,235
                                                                                     ---------          -------
     Total Current Assets                                                               58,273           53,381
 Net property and equipment, at cost                                                    16,576           16,182
 Notes receivable                                                                        2,471            2,811
 Cash surrender value of insurance policies                                              3,120            2,346
 Other assets                                                                            2,417            2,597
 Deferred tax assets                                                                     1,028            1,028
 Goodwill, net of amortization                                                          14,904           13,916
 Other intangible assets, net of amortization                                              882              814
                                                                                     ----------       ---------
     Total Assets                                                                      $99,671          $93,075
                                                                                       =======          =======
 LIABILITIES AND SHAREHOLDERS' EQUITY
 Current Liabilities:
 Accounts payable                                                                      $11,225         $  8,391
 Accrued payroll and related benefits                                                    4,927            4,356
 Other accrued liabilities                                                               4,366            2,969
 Billings in excess of costs and estimated earnings
     on uncompleted contracts                                                            4,527            2,732
 Long-term obligations due within one year                                               2,262            2,350
                                                                                     ---------         --------
     Total Current Liabilities                                                          27,307           20,798
 Long-term debt                                                                         10,281           11,441
  Other noncurrent obligations                                                           2,715            2,736
 Commitments and contingencies                                                              --               --
 Shareholders' Equity:
 Preferred stock, no par value, 5,000,000 shares authorized;
     no shares issued or outstanding                                                        --               --
 Common stock, no par value, 15,000,000 shares authorized;
     8,722,725 and 8,571,764 shares issued and outstanding at
     June 30, 1998 and December 31, 1997, respectively                                  42,874           42,184
 Retained earnings                                                                      16,494           15,916
                                                                                      --------          -------
     Total Shareholders' Equity                                                         59,368           58,100
                                                                                      --------          -------
     Total Liabilities and Shareholders' Equity                                        $99,671          $93,075
                                                                                       =======          =======
See accompanying notes.

</TABLE>
                                       3
<PAGE>

<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               (20)         183
                                                                  ---------       -------            ------       ------

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                                        $    0.07       $  0.06           $  0.07      $  0.14
                                                                  =========       =======           =======      =======

Shares used in computing basic earnings per share                     8,618         8,534             8,596        8,534
                                                                  =========       =======           =======      =======

Shares used in computing diluted earnings per share                   8,830         8,554             8,829        8,545
                                                                  =========       =======           =======      =======

See accompanying notes.
</TABLE>

                                       4

<PAGE>

<TABLE>
<CAPTION>



EMCON
CONSOLIDATED STATEMENTS OF CASH FLOWS

----------------------------------------------------------------------------------------------------------
                                                                                  Six months ended
                                                                                      June 30,
                                                                                    (Unaudited)
                                                                           -------------------------------
Increase (decrease) in cash and cash equivalents (in thousands)                 1998             1997
-------------------------------------------------------------------------- ---------------- --------------
<S>                                                                            <C>               <C>
Cash flow from operating activities:
Net income                                                                      $  594           $1,185
Adjustments to reconcile net income to net cash provided by (used for)
operating activities:
   Depreciation                                                                  1,895            1,908
   Amortization                                                                    316              312
   Bad debt expense                                                                250              499
   Gain on sale/disposal of property and equipment                                (256)             (15)
   Loss on disposition of laboratory                                                --              333
   Gain on disposition of assets                                                    --             (826)
   Increase in salary continuation plan                                            118               42
   Changes in operating assets and liabilities:
       Accounts receivable                                                      (7,924)          (4,213)
       Costs and estimated earnings in excess of billings on uncompleted          (848)            (929)
       contracts
       Inventory                                                                  (460)            (517)
       Prepaid expenses and other assets                                          (329)            (494)
       Notes receivable                                                            340           (2,849)
       Cash surrender value of insurance policies                                 (774)            (200)
       Other assets                                                                187            2,631
       Deferred tax assets                                                       1,000               --
       Accounts payable                                                          2,611              988
       Accrued payroll and related benefits                                        556           (1,235)
       Billings in excess of costs and estimated earnings on uncompleted         1,795            3,472
       projects
       Other accrued liabilities                                                 1,190              382
----------------------------------------------------------------------------------------------------------

          Net cash provided by operating activities                                261              474
----------------------------------------------------------------------------------------------------------
Cash flow from investing activities:
   Additions to property and equipment                                          (2,384)          (2,341)
   Acquisitions, net of cash acquired                                             (719)            (858)
   Addition to other intangible assets                                             (99)              --
   Net cash on disposition of laboratory                                            --            3,794
   Net cash from dispositions of assets                                             --              840
   Proceeds from sale of property and equipment                                    358              114
----------------------------------------------------------------------------------------------------------

          Net cash (used for) provided by investing activities                  (2,844)           1,549
----------------------------------------------------------------------------------------------------------
Cash flow from financing activities:
   Proceeds of new debt obligation                                                  --               69
   Payments of current and long term portion of debt                            (1,248)          (4,344)
   Issuance of common stock for cash, net of cancellations                          97               71
   Dividend payments                                                               (16)             (30)
----------------------------------------------------------------------------------------------------------

          Net cash used for financing activities                                (1,167)          (4,234)
----------------------------------------------------------------------------------------------------------
Decrease in cash and cash equivalents                                           (3,750)          (2,211)
Cash and cash equivalents, beginning of year                                     6,106            5,331
----------------------------------------------------------------------------------------------------------
Cash and cash equivalents, end of period                                        $2,356           $3,120
----------------------------------------------------------------------------------------------------------
See accompanying notes.
</TABLE>

                                       5
<PAGE>



                                      EMCON

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

1.   Basis of Presentation

     The accompanying  consolidated financial statements include the accounts of
     the Company and its  wholly-owned  subsidiaries  after  elimination  of all
     significant intercompany accounts and transactions.

     While the financial information is unaudited, the statements in this report
     reflect all adjustments, which are normal and recurring, that are necessary
     for a fair  presentation  of the  results  of  operations  for the  interim
     periods covered and of the financial  condition of the Company at the dates
     of the consolidated balance sheets. The consolidated  operating results for
     the interim periods presented are not necessarily indicative of performance
     for the entire year.

     These  consolidated  financial  statements  and  notes  should  be  read in
     conjunction with the Company's  consolidated  financial  statements for the
     fiscal year ended December 31, 1997.

2.   Restructuring Charges

     In the fourth  quarter of 1996,  senior  management  reviewed the Company's
     operational  and  administrative  functions  for  the  purpose  of  further
     improving the Company's competitiveness and overall profitability. Based on
     this  review,  the  Company's  Board  of  Directors  approved  a  strategic
     restructuring  plan to  reposition  the  Company to fully  exploit its core
     strengths in engineering, design, construction, operations and maintenance.
     The  plan  included  closure  or  downsizing  of  underperforming  offices,
     write-off  of  employment   contracts   for  former   employees  no  longer
     participating in the Company's affairs and employee  severance.  During the
     quarter ended June 30, 1998,  $13,000  relating to the  restructuring  were
     incurred  and charged  against the  established  reserve.  Through June 30,
     1998,  $392,000  of  restructuring  costs have been  incurred  and  charged
     against the  reserve and  $293,000  remains in other  accrued  liabilities,
     which includes present value adjustments during 1998 of $12,000.

3.   Acquisitions

     On April 3, 1998,  EMCON  acquired  all the  outstanding  capital  stock of
     Advanced  Analytical  Solutions,  Inc.  ("A2S"),  a Denver,  Colorado based
     provider,  with an office in  Philadelphia,  Pennsylvania,  of  alternative
     dispute resolution,  cost allocation, cost recovery, and litigation support
     services for, primarily,  superfund projects. The Company purchased A2S for
     $1,194,000,  in  stock  ($593,000),   cash  and  direct  acquisition  costs
     ($601,000).  The transaction  was accounted for as a purchase.  Goodwill of
     approximately  $1,150,000  is being  amortized  over thirty years using the
     straight  line  method.  Accumulated  amortization  at June 30,  1998,  was
     approximately  $10,000.  Additional  consideration  may  be  paid  for  the
     purchase  of A2S  subject to the  achievement  of  predetermined  operating
     performance  goals over the next two years. This acquisition would not have
     had a material  affect on net revenue,  net income,  or earnings per share,
     had it been effective at January 1, 1998.

                                       6

<PAGE>



     Effective May 1, 1997,  Organic Waste Technology,  Inc.  ("OWT"),  a wholly
     owned subsidiary of EMCON,  acquired all of the equity interest in National
     Earth Products, Inc. ("NEP"), a Lancaster,  Pennsylvania-based company with
     significant  expertise in landfill  civil  construction  and related  soils
     processing.  NEP was  acquired  for  $933,000 in cash and $800,000 in notes
     payable.  The  transaction  was accounted  for as a purchase.  Specifically
     identifiable  intangible  assets and goodwill of  approximately  $1,601,000
     resulting  from this  acquisition  are  included in goodwill  and are being
     amortized   over   twenty-five   years  using  the  straight  line  method.
     Accumulated  amortization as of June 30, 1998, was  approximately  $70,000.
     Included in goodwill,  is an additional $125,000 cash payment that was made
     to NEP  shareholders in May, 1998, as a result of their  attaining  certain
     predetermined operating performance goals. Additional  consideration may be
     paid for the purchase of NEP subject to the  achievement of certain earnout
     goals over the next year to be measured as of April, 1999. This acquisition
     would  not have had a  material  effect  on net  revenue,  net  income,  or
     earnings per share, had it been effective at January 1, 1997.

4.   Credit Agreement

     In  conjunction  with the  acquisition  of OWT, the Company  entered into a
     $20,000,000 secured credit agreement with its existing commercial bank (the
     "Credit Agreement"),  replacing its previous $10,000,000  unsecured line of
     credit. Under the new agreement, the Company borrowed $10,000,000 on a term
     loan basis with  interest  at a managed  rate not to exceed the prime rate.
     Principal is to be amortized  over seven years with any unpaid  amounts due
     and payable on June 30, 2001. In April 1997, following the infusion of cash
     upon  the  sale of CAS,  the  Company  prepaid,  on an  accelerated  basis,
     $3,000,000 of the then outstanding  principal balance of the term loan. The
     remaining  $10,000,000  under the Credit Agreement is available for working
     capital   purposes  (with  up  to  $5,000,000   also  being  available  for
     non-working  capital purposes).  The line of credit component of the Credit
     Agreement expires on August 27, 1998. The Company expects to renew the line
     of credit  component of the Credit  Agreement prior to its expiration.  The
     Credit  Agreement  contains  provisions  with  respect  to the  payment  of
     dividends  and  the  level  of  capital   expenditures   and  requires  the
     maintenance of specific levels of working  capital,  tangible net worth and
     continued quarterly profitability.

5.   Litigation

    As a professional  services firm engaged in  environmental-related  matters,
    the Company encounters potential liability, including claims for significant
    environmental damage in the normal course of business.  The Company is party
    to lawsuits and is aware of potential  exposure  related to certain  claims,
    but in the opinion of  management  the  resolution of these matters will not
    have a  material  adverse  effect on the  Company's  consolidated  financial
    position, results of operations or cash flows.


                                       7
<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                                   8,618            8,534          8,596            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                                               8,830            8,554          8,829            8,545
                                                                ========         ========        =======         ========
    Basic earnings per share                                    $   0.07         $   0.06        $  0.07         $   0.14
                                                                ========         ========        =======         ========
    Diluted earnings per share                                  $   0.07         $   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>

7.   Other

    In 1994, the Company converted to a  fifty-two/fifty-three  week fiscal year
    which will result in a fifty-two  week year in 1998.  The Company's year end
    falls  on the  Friday  closest  to the last day of the  calendar  year.  The
    Company also follows a five-four-four week quarterly cycle. For convenience,
    the accompanying consolidated financial statements have been shown as ending
    on the last day of the calendar period.

8.   Adoption of Statement 131

     Effective  January 1, 1998,  the Company  adopted the Financial  Accounting
     Standards  Board's  Statement of Financial  Accounting  standards  No. 131,
     Disclosure  about  Segments  of  an  Enterprise  and  Related  Information,
     ("Statement  131").  Statement 131 superseded FASB Statement 14,  Financial
     Reporting for Segments of a Business Enterprise.  Statement 131 establishes
     standards for the way that public business  enterprises  report information
     about operating  segments in annual financial  statements and requires that
     those enterprises  report selected  information about operating segments in
     interim  financial  reports.  The adoption of Statement  131 did not affect
     consolidated  results of operations or financial  position,  but did affect
     the disclosure of segment information. See note 9.

                                       8

<PAGE>



9.   Segment Reporting

     Description  of the types of services  from which each  reportable  segment
     derives its revenues.

     EMCON   provides   comprehensive    environmental   engineering,    design,
     construction,   operations  and  maintenance,   and  equipment  fabrication
     services  to a variety of public and  private  industrial  and solid  waste
     clients.  The  Company  is  comprised  of two  reportable  segments  -- the
     Operations and Construction  Division (EOC) and the  Professional  Services
     Division (PSD) -- and services three key service lines:  Solid Waste,  Site
     Restoration and Facility Services.

     In the first  quarter of 1997,  the  Company  had,  in  addition to the two
     reportable  segments listed above, a third reportable segment which was its
     laboratory  operations known as Columbia Analytical  Services,  Inc. (CAS).
     During the first quarter of 1997, the Company completed the sale of CAS.

     Measurement of segment profit or loss and segment assets.

     The Company evaluates performance of its reportable segments,  EOC and PSD,
     based on  operating  income or loss  before  and after  corporate  overhead
     allocations, but before interest income, interest expense, equity in income
     of affiliates  and minority  interest  income  (loss).  Corporate  overhead
     expenses are  substantially  allocated to the reporting  segments  based on
     revenue and/or  headcount when an item cannot be specifically  identifiable
     to a reporting segment.  The accounting policies of the reportable segments
     are the same as those  described in the summary of  significant  accounting
     policies as disclosed in EMCON's Form 10K as of December 31, 1997.

     Intersegment  sales consist primarily of labor and are marked up to provide
     the  supplying  reportable  segment  a measure  of  profit.  The  receiving
     reportable  segment records the transfer as an "Outside Service" and may or
     may not further mark up the labor cost prior to passing the cost through to
     its  customer.  If the cost is not  passed  through  to the  customer,  the
     receiving  reportable  segment records the transaction as an indirect cost.
     All intersegment accounts are eliminated in consolidation.

     Factors management used to identify the enterprise's reportable segments.

     EMCON's  reportable  segments  are  divisional  units that offer  different
     services.  The  reportable  segments are each managed  separately.  The PSD
     reportable  segment  concentrates on professional  engineering,  design and
     consulting  services  in  solid  waste,  site  restoration  and  facilities
     services.  The PSD reportable segment has regional  operations  situated in
     the North,  South,  Northwest  and  Southwest  of the United  States,  each
     overseen by an Area Operations Manager.  These regional operations have the
     same  operating   parameters   (services  offered  and  required  operating
     margins),  may serve the same national customers and often share personnel.
     For reportable segment reporting, these regional operations are aggregated.
     The  EOC  reportable  segment   concentrates  on  construction,   equipment
     fabrication  and  operations  and  maintenance  services,  primarily to the
     Company's solid waste clients.

     In  1997,  there  was  a  third  reportable  segment,  Columbia  Analytical
     Services,  Inc.,  a  laboratory  division  that was sold  during  the first
     quarter of 1997.

                                       9
<PAGE>

<TABLE>
<CAPTION>



     Segment Information
       ---------------------------------------------------------------------------------------------------
       (Three months ended June 30, 1998)                       PSD        EOC        Other         Total
       ---------------------------------------------------------------------------------------------------
       <S>                                                  <C>        <C>           <C>          <C>
       Gross revenues from:
            External subcontractors                         $20,284    $20,243       $  458       $40,985
            Intersegment revenues                               675        629           --         1,304
       Outside services from:
            External subcontractors                           4,742         18           16         4,776
            Intersegment services                               676        643            5         1,324
       Net revenues                                          15,541     20,211          457        36,209
       Depreciation expense                                     528        335           65           928
       Amortization expense                                      --         15          148           163
       Segment operating profit (loss) before                   474      2,393          126         2,993
       allocations
       Segment operating profit (loss) after allocations       (538)      1,860        (132)        1,190
       ---------------------------------------------------------------------------------------------------
       (Three months ended June 30, 1997)
       ---------------------------------------------------------------------------------------------------
       Gross revenues from:
            External customers                              $20,190    $12,920        $   4       $33,114
            Intersegment revenues                               362        511           --           873
       Outside services from:
            External subcontractors                           4,134      4,513           --         8,647
            Intersegment services                               584        268           --           852
       Net revenues                                          15,834      8,650          (17)       24,467
       Depreciation expense                                     559        365           91         1,015
       Amortization expense                                      --         26          135           161
       Segment operating profit (loss) before                 1,645      1,206           --         2,851
       allocations
       Segment operating profit (loss) after allocations        434        595           55         1,084
       ---------------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<CAPTION>


       ----------------------------------------------------------------------------------------------------------------
       (Six months ended June 30, 1998)                         PSD        EOC          CAS        Other         Total
       ----------------------------------------------------------------------------------------------------------------
       <S>                                                  <C>        <C>              <C>       <C>          <C>
       Gross revenues from:
            External customers                              $38,331    $30.975          N/A       $  458       $69,764
            Intersegment revenues                               872      1,153          N/A           --         2,025
       Outside services from:
            External subcontractors                           7,614        103          N/A           16         7,733
            Intersegment services                             1,248        794          N/A            5         2,047
       Net revenues                                          30,341     31,231          N/A          459        62,031
       Depreciation expense                                   1,081        678          N/A          136         1,895
       Amortization expense                                      --         30          N/A          286           316
       Segment operating profit (loss) before                 1,195      3,274          N/A          126         4,595
       allocations
       Segment operating profit (loss) after allocations       (795)     2,231          N/A         (103)        1,333
       Segment assets (1)
           Accounts receivable, net                          23,485     20,904          N/A          366        44,755
       ----------------------------------------------------------------------------------------------------------------

</TABLE>

                                       10
<PAGE>

<TABLE>
<CAPTION>



       -----------------------------------------------------------------------------------------------------------------
       (Six months ended June 30, 1997)                         PSD        EOC           CAS         Other        Total
       -----------------------------------------------------------------------------------------------------------------
       <S>                                                  <C>        <C>            <C>           <C>         <C>
       Gross revenues from:
            External customers                              $41,106    $18,908        $4,453        $  10       $64,477
            Intersegment revenues                               693      1,091           734           --         2,518
       Outside services from:
            External subcontractors                           7,641      4,513           275           --        12,429
            Intersegment services                             2,063        400             8           --         2,471
       Net revenues                                          32,095     15,086         4,904         (37)        52,048
       Depreciation expense                                   1,119        646           462          143         2,370
       Amortization expense                                      --         41            --          271           312
       Restructuring/other charges                               --         --            --         (75)          (75)
       Loss on disposition of laboratory                         --         --            --          333           333
       Gain on sale of assets                                    --        826            --           --           826
       Segment operating profit (loss) before                 3,029      2,278           108           --         5,415
       allocations
       Segment operating profit (loss) after allocations      1,266      1,332          (59)        (138)         2,401
       Segment assets(1)
            Accounts receivable, net                         26,689     11,201           N/A           --        37,890
       -------------------------------------------------- ---------- ---------- ------------- ------------ -------------
       (1)The Company  reviews its  consolidated  balance sheet and reviews only
          accounts receivable on a segment basis.
</TABLE>

<TABLE>
<CAPTION>

       -----------------------------------------------------------------------------------------------------------------

                                                                          Three months ended         Six months ended
                                                                               June 30,                  June 30,
       -----------------------------------------------------------------------------------------------------------------
       Three months ended June 30,                                            1998        1997          1998       1997
       -----------------------------------------------------------------------------------------------------------------
       <S>                                                                 <C>         <C>           <C>        <C>
       Revenues
       Total external revenues for reportable segments                     $40,527     $33,110       $69,306    $64,467
       Intersegment revenues for reportable segments                         1,304         873         2,025      2,518
       Other revenues                                                          458           4           458         10
       Elimination of intersegment revenues                                 (1,304)       (873)       (2,025)    (2,518)
                                                                           -------     -------       -------    -------
            Total gross consolidated revenues                               40,985      33,114        69,764     64,477
       Less outside services                                                (4,776)     (8,647)       (7,733)   (12,429)
                                                                           -------     -------       -------    -------
             Total net revenue                                             $36,209     $24,467       $62,031    $52,048
       -----------------------------------------------------------------------------------------------------------------
       Profit or Loss
       Total operating profit for reportable segments before               $ 2,993     $ 2,851       $ 4,595    $ 5,415
       allocations
       Overhead allocations expense                                         (1,545)     (1,836)       (3,033)    (2,876)
       Unallocated overhead                                                   (258)         69          (229)      (138)
                                                                           -------      ------       -------    -------
             Total operating profit after allocations                        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)           20       (183)
                                                                           --------     ------       -------    -------
            Income before provision for income taxes                       $ 1,035     $   760       $ 1,090    $ 1,823
       -----------------------------------------------------------------------------------------------------------------

       June 30,                                                                                  1998              1997
       -----------------------------------------------------------------------------------------------------------------
       Assets
       Accounts receivable for reportable segments                                           $44,755            $37,890
       Other current assets                                                                   13,518             10,867
       Net property and equipment at cost                                                     16,576             15,429
       Goodwill, net of amortization                                                          14,904             13,922
       Other assets                                                                            9,918             13,773
                                                                                             -------            -------
            Total consolidated assets                                                        $99,671            $91,881
       -----------------------------------------------------------------------------------------------------------------
</TABLE>

                                       11
<PAGE>




                                      EMCON

ITEM 2.       Management's  Discussion  and  Analysis of Financial Condition and
              Results Of Operations.

              The following  discussion  should be read in conjunction  with the
              consolidated  financial  statements  and notes  thereto  appearing
              elsewhere  in  this  Form  10-Q.   Certain   statements   in  this
              "Management's  Discussion and Analysis of Financial  Condition and
              Results  of  Operations,"   including   statements  regarding  the
              Company's  beliefs,   expectations  or  strategies  regarding  the
              future, constitute  forward-looking  statements within the meaning
              of Section  27A of the  Securities  Act of 1933 and Section 21E of
              the Securities Exchange Act of 1934. Although the Company believes
              that the expectations reflected in such forward-looking statements
              are based on reasonable  assumptions,  such statements are subject
              to risks and  uncertainties,  including  those discussed under the
              heading "Risk Factors" in the Company's Annual Report on Form 10-K
              for the year ended December 31, 1997 (the "1997 Form 10-K"),  that
              could  cause  actual  results  to  differ  materially  from  those
              projected.

RESULTS OF OPERATIONS

Current  Year-to-Date  ended June 30, 1998 versus Prior  Year-to-Date ended June
30, 1997.

Net Revenue:  Net revenue for the first six months of 1998 totaled $62,031,000 a
19.2% increase from  $52,048,000 for the first six months of 1997. At the end of
the first  quarter of 1997,  the Company  divested  its  laboratory  subsidiary,
Columbia Analytical Services,  Inc. (CAS); a reportable segment. CAS contributed
$4,904,000  to net revenue in the first  quarter of 1997.  Excluding net revenue
contributed  by CAS in the first  quarter of 1997,  net revenue from  continuing
operations  actually  increased  31.6% in the  first  six  months  of 1998  from
$47,144,000  in the same  period  in  1997.  The  increase  in net  revenue  was
primarily due to a 107.0%  increase in net revenue from EMCON's  Operations  and
Construction  (EOC) reportable  segment as the demand for its services continued
to  increase.  This  was  offset  by a 5.5%  decrease  in net  revenue  from the
Professional  Services  Division  reportable  segment (PSD) due to unanticipated
project  delays,  unusually  severe  weather  conditions and the impact from the
contraction of the PSD's West Coast operations throughout the course of 1997 and
the first six months of 1998.

Direct  Expenses:  Direct expenses  include  compensation for billable hours for
technical and professional staff and other project related expenses,  as well as
direct labor and materials  for in-house  testing and  construction  activities.
Direct  expenses for the first six months of 1998 totaled  $35,801,000,  a 44.3%
increase compared to direct expenses of $24,812,000  during the first six months
of 1997.  Excluding  the  impact  of CAS  (which  incurred  direct  expenses  of
$2,267,000 in the first quarter of 1997) direct  expenses  increased  58.8% from
$22,545,000  in the first six months of 1997.  As a  percentage  of net revenue,
direct expenses as reported increased from 47.7% in the first six months of 1997
to 57.7% in the first six months of 1998.  The increase was due in large part to
a shift in business mix resulting from the  divestiture of CAS, the  contraction
of the PSD reportable segment and the continued  expansion of the EOC reportable
segment.

                                       12

<PAGE>



Indirect Expenses: Indirect expenses include salary compensation for nonbillable
hours  of  professional,   technical  and   administrative   staff  and  general
administrative  expenses  such as rent,  bonuses,  benefits,  insurance,  legal,
depreciation  and  amortization.  Indirect  expenses for the first six months of
1998  totaled  $24,897,000,  a 2.0%  decrease  compared to indirect  expenses of
$25,403,000 for the first six months of 1997. Excluding the impact of CAS (which
incurred  indirect expenses of $2,529,000 in the first quarter of 1997) indirect
expenses  during the first six months of 1998  increased  8.8% from  $22,874,000
during the first six months of 1997.  As a percentage  of net revenue,  indirect
expenses  decreased  from  48.8% in the first six  months of 1997  (48.5%  after
excluding  the  impact  of CAS) to 40.1% in the first  six  months of 1998.  The
decrease was due in part to the above-noted shift in business mix, the expansion
of the EOC reportable segment, the contraction of the PSD reportable segment and
the continued positive impact of cost containment measures.

Adjustment  of  Restructuring  Accrual:  During the first  quarter of 1997,  the
Company reversed an accrual of $75,000 made as part of the restructuring actions
taken in the fourth quarter of 1996. The year end accrual was revised to reflect
lower than  anticipated  costs  associated  with the  abandonment and subsequent
sublease of certain office space.

Loss on Disposition of Laboratory: During the first quarter of 1997, the Company
completed the sale of CAS to the employees of CAS for  $4,000,000 in cash,  CAS'
promissory notes for $3,219,000  ("CAS Notes") and a continuing  preferred stock
interest in CAS valued at $500,000. The Company paid $206,000 in cash to CAS for
retired  employee  contracts  and for  accelerated  vesting of stock options and
other non vested stock  rights.  In  anticipation  of completing  the sale,  the
Company  recognized  impairment  in  the  value  of  its  investment  in  CAS of
$3,327,000 at the end of 1996.  As a result of several pre closing  adjustments,
the Company  recognized an additional  loss on  disposition  of CAS in the first
quarter of 1997 of $333,000.

Gain on Sale of Assets:  During the first quarter of 1997, the Company completed
the sale of one of its landfill  gas-to-energy  projects,  including the related
leasehold production rights and associated machinery and equipment.  The Company
recognized a gain on disposition of the project in the first quarter of 1997, of
$826,000.

Income From Operations:  Income from operations for the first six months of 1998
was $1,333,000,  a 44.5% decrease  compared to $2,401,000  during the comparable
period last year. Income from operations,  as a percent of net revenue decreased
to 2.1% for the first six months of 1998 from 4.6% in the  comparable  period in
1997.

Interest Income:  The Company recorded  interest income of $319,000 in the first
six months of 1998  compared to  $219,000  in the first six months of 1997.  The
increase  in  interest  income in the first six months of 1998  compared  to the
first six months of 1997 was primarily due to the recognition of interest income
on the CAS Notes.

Interest Expense. The Company incurred interest expense of $597,000 in the first
six months of 1998 compared to $648,000 in the first six months of 1997.



                                       13

<PAGE>



Quarters Ended June 30, 1998 and 1997

Net  Revenue.  Net  revenue  for  the  quarter  ended  June  30,  1998,  totaled
$36,209,000,  a 48.0%  increase from net revenue of  $24,467,000  for the second
quarter of 1997.  The  increase  in net revenue  was  primarily  due to a 133.7%
increase in net revenue from EMCON's Operations and Construction  Division (EOC)
reportable segment as the demand for its services continues to expand.  This was
offset by a 1.6% decrease in net revenue from the PSD reportable  segment due to
continued project delays,  and the impact from the contraction of the PSD's West
Coast operations throughout the course of 1997 and the first six months of 1998.

Direct  Expenses.  Direct expenses for the quarter ended June 30, 1998,  totaled
$21,979,000,  an 80.1%  increase from  $12,206,000  during the second quarter of
1997. As a percentage of net revenue,  direct  expenses  increased from 49.9% in
the second  quarter of 1997 to 60.7% in the second quarter of 1998. The increase
was due in large part to a shift in business mix resulting from the  divestiture
of  CAS,  the  contraction  of the PSD  reportable  segment  and  the  continued
expansion of the EOC reportable segment.

Indirect Expenses. Indirect expenses for the quarter ended June 30, 1998 totaled
$13,040,000,  a 16.7% increase from indirect expenses of $11,177,000  during the
second  quarter of 1997.  As a  percentage  of net  revenue,  indirect  expenses
decreased  from  45.7% in the  second  quarter  of 1997 to  36.0% in the  second
quarter  of  1998.  The  decrease  was due in part to the  above-noted  shift in
business mix, the expansion of the EOC reportable  segment,  the  contraction of
the PSD reportable segment and the continued positive impact of cost containment
measures.

Income From  Operations.  Income from  operations for the quarter ended June 30,
1998, was $1,190,000,  a 9.8% increase  compared to $1,084,000 during the second
quarter of 1997.  Income from operations,  as a percent of net revenue decreased
to 3.3% in the  second  quarter  of 1998 from 4.4% in the  comparable  period in
1997.

Interest Income. The Company recorded interest income of $151,000 in the quarter
ended June 30, 1998 compared to $125,000 in the second quarter of 1997.

Interest  Expense.  The  Company  incurred  interest  expense of $304,000 in the
quarter ended June 30, 1998 compared to $317,000 in the first quarter of 1997.

LIQUIDITY AND CAPITAL RESOURCES

During  the  first  six  months  of  1998,   the  Company's  uses  of  cash  for
non-operating  activities primarily consisted of repayment of debt in the amount
of  $1,248,000  and  additions  to  property  and  equipment  in the  amount  of
$2,384,000;   mainly  computers  and  field  equipment  and  developed  leachate
evaporation  system (LES)  projects.  Net cash provided by operating  activities
during the period was $261,000.


                                       14
<PAGE>



In  conjunction  with  the  acquisition  of  OWT,  the  Company  entered  into a
$20,000,000  secured  credit  agreement with its existing  commercial  bank (the
"Credit  Agreement"),  replacing  its  previous  $10,000,000  unsecured  line of
credit. Under the new agreement, the Company borrowed $10,000,000 on a term loan
basis with interest at a managed rate not to exceed the prime rate. Principal is
to be amortized over seven years with any unpaid amounts due and payable on June
30, 2001.  In April 1997,  following  the infusion of cash upon the sale of CAS,
the Company prepaid, on an accelerated basis, $3,000,000 of the then outstanding
principal  balance of the term loan. The remaining  $10,000,000 under the Credit
Agreement is available for working capital  purposes (with up to $5,000,000 also
being available for non-working capital purposes).  The line of credit component
of the Credit Agreement expires on August 27, 1998. The Company expects to renew
the line of credit  component of the Credit  Agreement  prior to its expiration.
The  Credit  Agreement  contains  provisions  with  respect  to the  payment  of
dividends and the level of capital  expenditures and requires the maintenance of
specific levels of working capital,  tangible net worth and continued  quarterly
profitability.

The Company  believes that its cash on hand and cash generated from  operations,
together  with its  available  bank  financing  will be  sufficient  to meet the
Company's capital needs for at least the next twelve months.






                                       15

<PAGE>




                                      EMCON

                            PART II OTHER INFORMATION

Items 1. - 3.     Not applicable.

Item 4.           Submission of Matters to a Vote of Security-Holders

On May 28, 1998,  the Annual Meeting of  Shareholders  of EMCON was held at 1921
Ringwood Ave., San Jose,  California.  Of the 8,572,862 shares outstanding as of
the record date,  7,697,769 shares were present or represented by proxies at the
meeting.

Election of  Directors.  An election of  directors  was held with the  following
individuals being elected to the Board of Directors:

                                                 For                 Withheld
        Douglas P. Crane                      6,803,314              894,455
        Eugene M. Herson                      7,137,548              560,221
        Richard A. Peluso                     7,143,053              554,716
        Donald R. Kerstetter                  6,801,098              896,671
        Peter Vardy                           6,803,798              893,971
        Franklin J. Agardy                    6,800,855              896,914

Approval of 1998 Stock Option Plan. The  shareholders  voted to approve the 1998
Stock Option Plan. The proposal  received  2,770,870 votes for,  2,753,927 votes
against, 160,888 abstentions and 2,012,084 broker non-votes.

Ratification of Appointment of Independent  Auditors.  The shareholders voted to
ratify the appointment of Ernst & Young LLP as EMCON's independent  auditors for
the fiscal year ending December 31, 1998. The proposal received  7,589,152 votes
for, 91,388 votes against, and 17,229 abstentions.

Item 5.           Not applicable.

Item 6.           Exhibits and Reports

      (a)         Exhibits - See Index to Exhibits on Page 18

      (b)         Reports  on Form 8-K - No  reports on Form 8-K were filed with
                  the  Securities  and  Exchange  Commission  during the quarter
                  ended June 30, 1998.


                                     16

<PAGE>



                                      EMCON


                                   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:  July 27, 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)



                                       17
<PAGE>



                                INDEX TO EXHIBITS
                                                                  Sequentially
   Exhibit                                                         Numbered
   Number                                                            Page
--------------                                                   --------------
     2.1       Stock  Purchase  Agreement  dated January 30,            *
               1996, among Organic Waste Technologies,  Inc.
               ("OWT"),    Registrant    and   the   selling
               shareholders   and  option  holders  of  OWT,
               incorporated by reference from Exhibit 2.1 of
               the  Current  Report on Form 8-K dated  March
               14, 1996, (the "March 1996 8-K").

     2.2       Asset   Purchase   Agreement   between   Yolo           *
               Energy  Partners,  Inc.,  Yolo  Landfill  Gas
               Corporation,   EMCON,   Yolo  Neo  LLC,   and
               Minnesota  Methane  LLC  dated  December  31,
               1996,  incorporated by reference from Exhibit
               10.20 of the  Annual  Report on Form 10-K for
               the fiscal year ended  December 31, 1996 (the
               "1996 10-K").

     2.3       Acquisition   Agreement   between  EMCON  and           *
               its   wholly   owned   subsidiary,   Monterey
               Landfill Gas Corporation,  and Biomass Energy
               Partners  V,  L.P.,   dated  March  6,  1997,
               incorporated  by reference from Exhibit 10.22
               of the 1996 10-K.

     2.4       Stock   Purchase  Agreement  dated  April  4,           *
               1997 among  Registrant,  Columbia  Analytical
               Services,  Inc.  (`CAS"),  Northwest Trust as
               trustee of the CAS Employee  Stock  Ownership
               Trust and certain senior management employees
               of  CAS,   incorporated   by  reference  from
               Exhibit  2.4  of the  Registrant's  Quarterly
               Report  on Form 10-Q for the  fiscal  quarter
               ended March 31, 1997 (the "March 1997 10-Q").

     2.5       Stock  Purchase  Agreement  dated  April  30,          *
               1997 among  Registrant,  OWT,  National Earth
               Products,   Inc.   ("NEP")  and  the  selling
               stockholders   of   NEP,    incorporated   by
               reference  from Exhibit 2.5 of the March 1997
               10-Q.

     2.6       Agreement  and Plan of  Reorganization  among          *
               Registrant,  Advanced  Analytical  Solutions,
               Inc.  ("A2S") and certain other parties dated
               April 3, 1998, incorporated by reference from
               Exhibit 2.6 of the  Quarterly  Report on Form
               10-Q for the fiscal  quarter  ended March 31,
               1998 (the "March 1998 10-Q").

     3.1       Articles   of   Incorporation,   as  amended,          *
               incorporated by reference from Exhibit 3.1 of
               the  Registrant's  Registration  Statement on
               Form  S-1  (File  No.   33-16337)   effective
               September    16,    1987   (the   "Form   S-1
               Registration Statement").

     3.2       Certificate of Amendment of Restated Articles          *
               of  Incorporation  as filed on May 24,  1988,
               incorporated by reference from Exhibit 3.2 of
               the Annual Report on Form 10-K for the fiscal
               year  ended  December  31,  1988  (the  "1988
               10-K").

     3.3       Certificate of Amendment of Restated Articles          *
               of  Incorporation  as filed on June 4,  1991,
               incorporated by reference from Exhibit 4.1 of
               the  Quarterly  Report  on Form  10-Q for the
               fiscal quarter ended June 30, 1991 (the "June
               1991 10-Q").


                             18
<PAGE>







                                                                   Sequentially
   Exhibit                                                           Numbered
   Number            INDEX TO EXHIBITS (Continued)                     Page
--------------                                                   ---------------
    3.3        Bylaws, as amended, incorporated by reference            *
               from Exhibit 4.2 of the June 1991 10-Q. 

    10.1       EMCON 1986  Incentive  Stock  Option Plan and            *(1)
               Amendment,  incorporated  by  reference  from
               Exhibit  10.15 of the  Form S-1  Registration
               Statement.

    10.2       Form  of   Agreement   pursuant   to   Salary            *(1)
               Continuation Plan,  incorporated by reference
               from   Exhibit   10.17   of  the   Form   S-1
               Registration Statement.

    10.3       Schedule  identifying  Agreements pursuant to            *(1)
               Salary  Continuation Plan between  Registrant
               and  certain   employees,   incorporated   by
               reference    from   Exhibit   10.3   of   the
               Registrant's  Annual  Report on Form 10-K for
               the fiscal year ended  December 31, 1997 (the
               "1997 10-K").

    10.4       Form  of  Indemnity   Agreement  between  the            *
               Registrant  and  each  of  the   Registrant's
               officers  and  directors,   incorporated   by
               reference   from   Exhibit   10.20   of   the
               Registrant's  Annual  Report on Form 10-K for
               the fiscal year ended  December 31, 1988 (the
               "1988 10-K").

    10.5       EMCON  1988  Stock  Option  Plan,  amended by            *(1)
               shareholder   approval   on  May  25,   1994,
               including form of  Nonqualified  Stock Option
               Agreement (Outside  Directors),  incorporated
               by    reference    from   Exhibit   10.9   of
               Registrant's  Quarterly  Report  on Form 10-Q
               for the fiscal  quarter  ended June 30,  1994
               (the "June 30, 1994 10-Q").

    10.6       EMCON    Employee    Stock    Purchase   Plan            *(1)
               incorporated  by reference from Exhibit 10.10
               of the Registrant's  Quarterly Report on Form
               10-Q for the  fiscal  quarter  ended June 30,
               1995.

    10.7       EMCON  Restricted   Stock  Plan  incorporated            *(1)
               by reference from Exhibit 10.15 of the Annual
               Report on Form 10-K for the fiscal year ended
               December 31, 1990.

    10.8       EMCON  Deferred  Compensation  Plan effective            *(1)
               January 1, 1994,  incorporated  by  reference
               from Exhibit 10.12 of the Registrant's Annual
               Report on Form 10-K for the fiscal year ended
               December 31, 1993 (the "1993 10-K").

     10.9      Trust   Agreement  for  the  EMCON   Deferred            *(1)
               Compensation  Plan  and  Salary  Continuation
               Plan Trust dated  February 19, 1994,  between
               Registrant   and  Wells  Fargo   Bank,   N.A.
               incorporated  by reference from Exhibit 10.13
               of the 1993 10-K.

     10.10     Agreement   between   Eugene  M.  Herson  and            *(1)
               Registrant    dated    November   30,   1995,
               incorporated  by reference from Exhibit 10.21
               of  Registrant's  Annual  Report on Form 10-K
               for the fiscal year ended  December  31, 1995
               (the "1995 10-K").

                             19
<PAGE>







                                                                  Sequentially
   Exhibit                                                         Numbered
   Number          INDEX TO EXHIBITS (Continued)                     Page
--------------                                                   ---------------
    10.12      Credit   Agreement   between   The   Bank  of           *
               California,   N.A.   and   Registrant   dated
               February 29, 1996,  incorporated by reference
               from Exhibit 10.2 of the March 1996 8-K.

    10.13      Security   Agreement   between  The  Bank  of           *
               California,   N.A.   and   Registrant   dated
               February 29, 1996,  incorporated by reference
               from Exhibit 10.3 of the March 1996 8-K.

    10.14      Pledge   Agreement   between   The   Bank  of           *
               California,   N.A.   and   Registrant   dated
               February 29, 1996,  incorporated by reference
               from Exhibit 10.4 of the March 1996 8-K.

    10.15      Eurodollar Rate Option Agreement  between The           *
               Bank of California, N.A. and Registrant dated
               February 29, 1996,  incorporated by reference
               from Exhibit 10.5 of the March 1996 8-K.

    10.16      Fixed  Rate  Amortization   Option  Agreement           *
               between  The  Bank of  California,  N.A.  and
               Registrant    dated    February   29,   1996,
               incorporated  by reference  from Exhibit 10.6
               of the March 1996 8-K.

    10.17      Note Agreement among the Registrant, OWT, and          *
               certain  employees of OWT ,  incorporated  by
               reference from Exhibit 10.1 of the March 1996
               8-K.

    10.18      Rescission and  Reformation  Agreement  dated          *
               effective  November 1, 1996 among EMCON, OWT,
               and certain employees of OWT, incorporated by
               reference  from  Exhibit  10.18  of the  1996
               10-K.

    10.19      New Note Agreement dated  effective  November          *
               1,  1996  among   EMCON,   OWT  and   certain
               employees of OWT,  incorporated  by reference
               from Exhibit 10.19 of the 1996 10-K.

    10.20      Second  Amendment to Credit  Agreement  dated          *
               effective  January  27,  1997 among EMCON and
               Union  Bank  of  California,  N.A.  (formerly
               known  as  The  Bank  of  California,  N.A.),
               incorporated  by reference from Exhibit 10.21
               of the 1996 10-K.

    10.21      Third  Amendment  to Credit  Agreement  dated          *
               effective  March  27,  1997  among  EMCON and
               Union  Bank  of  California,  N.A.  (formerly
               known  as  The  Bank  of  California,  N.A.),
               incorporated  by reference from Exhibit 10.23
               of the 1996 10-K.

    10.22      Convertible Notes dated April 30, 1997 issued          *
               by EMCON to Dennis Grimm and Charles Gearhart
               in the principal  amounts of $400,798.40  and
               $399,201.60,  respectively,  incorporated  by
               reference  from  Exhibit  10.22 of the  March
               1997 10-Q.


                             20
<PAGE>




                                                                  Sequentially
   Exhibit                                                          Numbered
   Number         INDEX TO EXHIBITS (Continued)                       Page
--------------                                                    --------------

    10.23      Lease Agreement dated April 4, 1997,  between            *
               EMCON and Columbia Analytical Services, Inc.,
               incorporated  by reference from Exhibit 10.23
               of the March 1997 10-Q.

    10.24      Amendment    1997-I    to   EMCON    Deferred            *(1)
               Compensation  Plan dated  effective  February
               22,  1997,  incorporated  by  reference  from
               Exhibit 10.24 of the  Registrant's  Quarterly
               Report  on Form 10-Q for the  fiscal  quarter
               ended  June 30,  1997  (the  "June  30,  1997
               10-Q").

    10.25      Fourth  Amendment to Credit  Agreement  dated            *
               effective June 24, 1997 among EMCON and Union
               Bank of  California,  N.A.,  incorporated  by
               reference  from Exhibit 10.25 of the June 30,
               1997 10-Q.

    10.26      Amended and Restated Agreement between Eugene            *(1)
               M. Herson and  Registrant  dated  November 3,
               1997,  incorporated by reference from Exhibit
               10.26 of the 1997 10-K.

    10.27      Amended  and  Restated  Agreement  between R.            *(1)
               Michael   Momboisse  and   Registrant   dated
               November 3, 1997,  incorporated  by reference
               from Exhibit 10.27 of the 1997 10-K.

    10.28      Deferred   Compensation   Plan,  Amended  and            *(1)
               Restated    effective    January   1,   1998,
               incorporated  by reference from Exhibit 10.28
               of the 1997 10-K.

    10.29      Registration     Rights    Agreement    among            *
               Registrant,  and the former  shareholders  of
               A2S  dated  April 3,  1998,  incorporated  by
               reference  from  Exhibit  10.29 of the  March
               1998 10-Q.

    10.30      Secured  Promissory Note of Timothy M. Keaten            *
               dated April 3, 1998, in the principal  amount
               of $225,000,  incorporated  by reference from
               Exhibit 10.30 of the March 1998 10-Q.

    10.31      EMCON 1998 Stock Option Plan,  with  standard           22
               form of  Incentive  Stock  Option  Agreement,
               Non-Statutory   Stock  Option  Agreement  and
               Non-Statutory Stock Option Agreement (outside
               Director Option) attached.

    10.32      Sixth  Amendment  to Credit  Agreement  among           76(1)
               Registrant and Union Bank of California dated
               June 1, 1998.


      27       Financial Data Schedule, included herein.               81

 *  Incorporated by reference
(1)  Management  contract or  compensatory  plan or  arrangement  required to be
     filed as an exhibit to this form pursuant to Item 14(c) of the instructions
     to Form 10-K.

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