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 March 31, 1997

                                       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: (415) 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 [ ]

8,535,372 shares of Common Stock Issued and Outstanding as of May 13, 1997.



                                       1
<PAGE>




                                      EMCON
                                      INDEX
                               REPORT ON FORM 10-Q
                      FOR THE QUARTER ENDED MARCH 31, 1997




                                                                         Page
                                                                        Number

FACING SHEET..........................................................     1

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

PART I.   FINANCIAL INFORMATION

    Item 1.      Financial Statements

                 Consolidated Balance Sheets -
                 March 31, 1997 and December 31, 1996.................     3

                 Consolidated Statements of Income -
                 Three months ended March 31, 1997 and 1996...........     4

                 Consolidated Statements of Cash Flows -
                 Three months ended March 31, 1997 and 1996...........     5 

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

   Item 2.       Management's Discussion and Analysis of
                     Financial Condition and Results of Operations....     9

PART II.   OTHER INFORMATION..........................................     12

Signatures............................................................     13

Index to Exhibits.....................................................     14


                             2
<PAGE>


<TABLE>
<CAPTION>

                                      EMCON
                           CONSOLIDATED BALANCE SHEETS
----------------------------------------------------------------------------------------------------------------------------------
                                                                                                         March 31,      December 31,
                                                                                                           1997             1996
(In thousands, except share amounts)                                                                    (Unaudited)      (Audited)
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                                                                       <C>                 <C>
ASSETS                   
Current Assets:
Cash and cash equivalents ....................................................................            $ 7,901            $ 5,331
Accounts receivable, net of allowance for doubtful accounts of $1,226
     and $951 at March 31, 1997 and December 31, 1996, respectively ..........................             34,615             32,860
Costs and estimated earnings in excess of billings on
     uncompleted contracts ...................................................................              1,250                904
Prepaid expenses and other current assets ....................................................              4,965              4,425
Assets held for sale .........................................................................               --                9,382
                                                                                                          -------            -------

    Total Current Assets .....................................................................             48,731             52,902

Net property and equipment, at cost ..........................................................             14,552             14,722

Other assets .................................................................................              7,811              4,800
Deferred tax assets ..........................................................................              4,818              4,818
Goodwill, net of amortization ................................................................             12,596             12,716
Other intangible assets, net of amortization .................................................                905                954
                                                                                                          -------            -------

    Total Assets .............................................................................            $89,413            $90,912
                                                                                                          =======            =======

LIABILITIES AND SHAREHOLDERS' EQUITY
Current Liabilities:
Accounts payable .............................................................................            $ 4,527            $ 5,483
Accrued payroll and related benefits .........................................................              3,671              6,020
Other accrued liabilities ....................................................................              5,333              4,454
Billings in excess of costs and estimated earnings
     on uncompleted contracts ................................................................              1,283                 94
Long-term obligations due within one year ....................................................              2,226              2,250
                                                                                                          -------            -------

    Total Current Liabilities ................................................................             17,040             18,301

Long-term debt ...............................................................................             14,023             14,667
 Other noncurrent obligations ................................................................              1,810              2,132

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;
    8,535,372 and 8,512,688 shares issued and outstanding at
    March 31, 1997 and December 31, 1996, respectively .......................................             42,059             42,001
Retained earnings ............................................................................             14,481             13,811
                                                                                                          -------            -------

    Total Shareholders' Equity ...............................................................             56,540             55,812
                                                                                                          -------            -------

    Total Liabilities and Shareholders' Equity ...............................................            $89,413            $90,912
                                                                                                          =======            =======
</TABLE>

See accompanying notes

                             3
<PAGE>

                                      EMCON

                        CONSOLIDATED STATEMENTS OF INCOME
                                   (Unaudited)
<TABLE>
<CAPTION>

-------------------------------------------------------------------------------
                                                           Three months ended
                                                                March 31,
                                                           ------------------
(In thousands, except per share amounts)                   1997          1996
                                                        
-------------------------------------------------------------------------------
<S>                                                       <C>           <C> 
Gross revenue ....................................      $ 31,363       $ 28,564
Outside services, at cost ........................         3,782          3,957
                                                        --------       --------

   Net revenue ...................................        27,581         24,607

Costs and expenses:
   Direct expenses ...............................        12,606          9,689
   Indirect expenses .............................        14,226         14,799
   Restructuring .................................           (75)          --
   Loss on disposition of laboratory .............           333           --
   Gain on sale of assets ........................          (826)          --
                                                        --------       --------

   Income from operations ........................         1,317            119

Interest income (expense), net ...................          (237)           (22)
Equity in gain (loss) of affiliates ..............            18            (22)
Minority interest ................................           (35)           (22)
                                                        --------       --------

Income before provision for income taxes .........         1,063             53

Provision for income taxes .......................           372             19
                                                        --------       --------

Net income .......................................      $    691       $     34
                                                        ========       ========

Income per share .................................      $   0.08       $   0.01
                                                        ========       ========




</TABLE>

See accompanying notes


                              4
<PAGE>


                                      EMCON

                      CONSOLIDATED STATEMENTS OF CASH FLOWS
                                   (Unaudited)
<TABLE>
<CAPTION>

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

                                                                                                              Three months ended
                                                                                                                    March 31,
                                                                                                              -------------------
Increase (decrease) in cash and cash equivalents (in thousands)                                               1997           1996
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                                                                             <C>           <C>

Cash flow from operating activities:
   Net income ......................................................................................        $   691         $    34
   Adjustments to reconcile net income to net cash
     used for operating activities:
     Depreciation and amortization .................................................................          1,044           1,463
     Gain (loss) on sale/disposal of property and equipment ........................................           (142)             29
     Loss on disposition of laboratories ...........................................................            333            --
     Gain on disposition of assets .................................................................           (826)           --
     Increase in salary continuation plan ..........................................................             17              11
     Changes in operating assets and liabilities:
       Accounts receivable .........................................................................         (1,755)             (8)
       Prepaid expenses and other current assets ...................................................           (450)           (902)
       Other assets ................................................................................           (147)           (384)
       Accounts payable ............................................................................           (416)           (472)
       Accrued payroll and related benefits ........................................................         (1,247)           (241)
       Other accrued liabilities ...................................................................          1,793             272
-----------------------------------------------------------------------------------------------------------------------------------
   Net cash used for operating activities ..........................................................         (1,105)           (198)
-----------------------------------------------------------------------------------------------------------------------------------
Cash flow from investing activities:
   Additions to property and equipment .............................................................         (1,157)           (621)
   Maturities of available for sale securities .....................................................           --               514
   Acquisitions,  net of cash acquired .............................................................           --            (4,007)
   Net cash on disposition of laboratory ...........................................................          3,794            --
   Net cash from disposition of assets .............................................................            840            --
   Proceeds from sale of property and equipment ....................................................            512               6
-----------------------------------------------------------------------------------------------------------------------------------
   Net cash provided by (used for) investing activities ............................................          3,989          (4,108)
-----------------------------------------------------------------------------------------------------------------------------------
Cash flow from financing activities:
   Dividend payments ...............................................................................            (21)           --
   Payment of current and noncurrent obligations ...................................................           (619)           (152)
   Issuance of common stock for cash ...............................................................             76             527
   Proceeds of new debt obligation .................................................................            250            --
-----------------------------------------------------------------------------------------------------------------------------------
   Net cash provided by (used for) financing activities ............................................           (314)            375
-----------------------------------------------------------------------------------------------------------------------------------
Increase (decrease) in cash and cash equivalents ...................................................          2,570          (3,931)
Cash and cash equivalents, beginning of year .......................................................          5,331           9,451
-----------------------------------------------------------------------------------------------------------------------------------
Cash and cash equivalents, end of period ...........................................................        $ 7,901         $ 5,520
-----------------------------------------------------------------------------------------------------------------------------------

</TABLE>

See accompanying notes


                             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 balance  sheets.  The  operating  results  for the  interim  periods
     presented  are not  necessarily  indicative of  performance  for the entire
     year.

     These financial statements and notes should be read in conjunction with the
     Company's  consolidated  financial  statements  for the  fiscal  year ended
     December 31, 1996.

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 March 31, 1997,  $98,000 relating to the  restructuring  were
     incurred and charged  against the established  reserve.  At March 31, 1997,
     $940,000 of accrued  restructuring costs, net of a $75,000 reduction due to
     earlier than anticipated  subleasing of abandonded  office space,  remained
     and were  included  in other  accrued  liabilities.  To-date,  $217,000  of
     restructuring costs related to these actions have been incurred.

    In December 1994, as a result of changes in senior management, the Company's
    Board of Directors  approved a corporate  restructuring  plan which included
    the write off of  employment  contracts  with no  current  or future  value,
    termination of personnel,  and the  elimination or abandonment of excess and
    underperforming  assets and  facilities.  During the quarter ended March 31,
    1997,  $27,000  of cash  charges  related  to the  1994  restructuring  were
    incurred and charged against the established  reserve,  bringing the reserve
    to a zero balance.  To-date,  $1,169,000 of  restructuring  costs related to
    these actions have been incurred.



                             6
<PAGE>



3.   Acquisition

     On February 29, 1996,  EMCON acquired all of the outstanding  capital stock
     of  Organic  Waste   Technologies,   Inc.   ("OWT"),   a  Cleveland   based
     construction,   equipment  and  operations  and  maintenance  company  with
     significant expertise in solid waste management.

     The following  summarizes  the unaudited pro forma net revenue,  net income
     (loss) and net income  (loss) per share for the  combined  company  for the
     three  month  periods  ended  March 31,  1997 and 1996 had the  acquisition
     occurred at the beginning of each period presented.

                                                    (unaudited)
                                             Three months ended March 31,
                                             ----------------------------
       (in thousands)                        1997                 1996
       ----------------------------------------------------------------------
       Net revenue                         $27,581              $27,506
       Net income (loss)                       691                 (282)
       Income (loss) per share             $  0.08             $ (0.03)
       -------------------------------------------------------------------

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,
     replacing its previous $10,000,000  unsecured line of credit. Under the new
     agreement,  the Company  borrowed  $10,000,000 on a long term basis with an
     interest  rate not to exceed the prime rate.  Principal  is to be amortized
     over seven  years,  but with any unpaid  amount  finally due and payable on
     June 30, 2001.  The  remaining  $10,000,000  under the credit  agreement is
     available on a line of credit basis for working  capital  purposes (with up
     to $5,000,000  available for  non-working  capital  purposes).  The line of
     credit component of the credit agreement expires on May 31, 1997.

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 financial position,  results
    of operations or cash flows.

6.   Income Per Share

    Income per share for the three  months  ended March 31, 1997 is based on the
    weighted common and dilutive common equivalent shares  outstanding using the
    treasury stock method.  Common  equivalent  shares  include shares  issuable
    under the Company's stock option plans.  Primary and fully diluted  earnings
    per share are substantially the same.

                             7
<PAGE>

    Income per share for the three  months  ended March 31, 1996 is based on the
    weighted  average  number of common and dilutive  common  equivalent  shares
    outstanding using the modified treasury stock method.

    In February 1997, the Financial  Accounting Standards Board issued Statement
    No. 128,  "Earnings  per Share," which is required to be adopted on December
    31,  1997.  At that time,  the Company will be required to change the method
    currently  used to  compute  earnings  per  share and to  restate  all prior
    periods.  Under the new  requirements  for calculating  primary earnings per
    share, the dilutive effect of stock options will be excluded.  The impact is
    expected  to result in no change to the primary  earnings  per share for the
    first  quarter  ended  March 31,  1997 and a $0.01  decrease  to the primary
    earnings per share for the first quarter ended March 31, 1996. The impact of
    Statement 128 on the  calculation  of fully  diluted  earnings per share for
    these quarters is not expected to be material.

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 1997.  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  financial statements have been shown as ending on the last
    day of the calendar period.



                             8
<PAGE>


                                      EMCON

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

RESULTS OF OPERATIONS

NET REVENUE. Net revenue for the first quarter of 1997 totalled  $27,581,000,  a
12.1% increase from  $24,607,000  for the first quarter of 1996. The increase in
net revenue is due in part to the  inclusion of OWT for all of the first quarter
of 1997,  as compared to only one month of the first  quarter of 1996  following
its acquisition on February 29, 1996.  Excluding the net revenue contribution of
OWT  ($6,417,000  and  $1,675,000 in the quarters ended March 31, 1997 and 1996,
respectively), net revenue for the quarter totalled $21,164,000; a 7.7% decrease
from net revenue of  $22,932,000  in the first quarter of 1996.  The decrease in
net  revenue  is  primarily  attributable  to  lower  demand  for the  Company's
professional  services in the Company's  South and Southwest areas combined with
the planned reduction in headcount  companywide  throughout 1996, offset in part
by stronger demand for such services in the Company's North and Northwest areas.

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  laboratory  testing and  construction
activities.  Direct expenses for the first quarter of 1997 totalled $12,606,000,
a 30.1% increase from the $9,689,000 for the same period in 1996.  Excluding the
impact of OWT,  direct  expenses  for the quarter  totalled  $8,105,000,  a 5.1%
decrease compared to direct expenses of $8,544,000 in the first quarter of 1996.
Excluding  the  impact  of OWT,  direct  expenses  as a percent  of net  revenue
increased to 38.3% in the first  quarter of 1997  compared to 37.3% in the first
quarter of 1996.

INDIRECT EXPENSES. Indirect expenses include salary compensation for nonbillable
hours  for  professional,   technical  and  administrative  staff,  and  general
administrative expenses such as rent, bonuses,  benefits,  insurance,  legal and
depreciation.   Indirect  expenses  for  the  first  quarter  of  1997  totalled
$14,226,000,  a 3.9% decrease from indirect expenses of $14,799,000 in the first
quarter of 1996.  Excluding the impact of OWT, indirect expenses for the quarter
totalled  $12,648,000,  a  12.5%  decrease  compared  to  indirect  expenses  of
$14,459,000 in the first quarter of 1996.

Excluding  the impact of OWT,  indirect  expenses  as a percent  of net  revenue
decreased to 59.7% in the first  quarter of 1997  compared to 63.1% in the first
quarter of 1996.  The  decrease  was  attributable  to improved  utilization  of
technical  and  professional  staff  as  well  as the  positive  impact  of cost
containment and restructuring measures put in place at the end of 1996.

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.

                                       9
<PAGE>

LOSS ON DISPOSITION OF LABORATORY. During the first quarter of 1997, the Company
completed the sale of its laboratory  subsidiary,  Columbia Analytical Services,
Inc.  ("CAS"),  to the employees of CAS for  $4,000,000 in cash,  CAS promissory
notes for $3,219,000 and a continuing  preferred stock interest in CAS valued at
$500,000.  The  Company  paid to CAS  $206,000  in  cash  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 $333,000.

GAIN ON SALE OF ASSETS.  During the quarter  ended March 31,  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 of $826,000.

INCOME FROM OPERATIONS. Income from operations for the first quarter of 1997 was
$1,317,000 compared to $119,000 during the comparable period last year.

INTEREST INCOME (EXPENSES) NET. The Company recorded  interest  expense,  net of
interest  income of $237,000 in the first quarter of 1997 compared to $22,000 in
the comparable quarter last year. The increase was due primarily to increases in
long term debt  incurred  for purposes of financing  the  acquisition  of OWT in
February  of  1996  and  the  subsequent  expansion  of  one of  OWT's  landfill
gas-to-energy projects.

LIQUIDITY AND CAPITAL RESOURCES

During  the  first  quarter  of  1997,  the  Company   financed  its  operations
principally from cash and marketable securities on hand, cash generated from the
disposition  of assets,  and from the  return on  investment  on its cash,  cash
equivalents and marketable  securities.  Net cash used for operating  activities
during the first quarter of 1997 was $1,105,000.  At March 31, 1997, the Company
had cash and cash equivalents of $7,901,000.

In  conjunction  with  the  acquisition  of  OWT,  the  Company  entered  into a
$20,000,000   secured  credit  agreement  with  its  existing  commercial  bank,
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, but with any unpaid amount finally 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


                                       10
<PAGE>

of the Credit  Agreement  expires on May 31, 1997. 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  invested  $1,157,000  in the first  quarter of 1997 in additions to
property and equipment;  mainly computers,  field equipment and the expansion of
its equipment fabrication facilities.

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.


                                       11
<PAGE>




                                      EMCON

                            PART II OTHER INFORMATION

Items 1. - 4.     Not applicable.

Item 5.           Other Information

       On April  30,  1997,  EMCON  acquired  all of the  outstanding  equity of
       National  Earth  Products,  Inc.  ("NEP")  for cash of  $860,780  and the
       issuance  of  EMCON's  convertible  promissory  notes  in  the  aggregate
       principal amount of $800,000.  Approximately 50% of the convertible notes
       are  due on  May 1,  2000  with  the  balance  due  on May 1,  2002.  The
       indebtedness  bears  interest  at  the  rate  of  8%  per  annum  and  is
       convertible  into EMCON Common  Stock at a conversion  price of $6.50 per
       share.  The  former  shareholders  of NEP are also  eligible  to  receive
       additional  earn out payments in each of the three  twelve month  periods
       immediately  following the acquisition;  which earn out payments are tied
       to the financial  performance of NEP. NEP is a  Pennsylvania-based  solid
       waste  construction  company with  specialized  expertise in securing and
       processing  natural landfill cover and liner materials,  such as dirt and
       clay.

Item 6.           Exhibits and Reports

(a)   Exhibits - See Index to Exhibits on Page 14

(b)   Reports  on Form  8-K - No  reports  on  Form  8-K  were  filed  with  the
      Securities  and  Exchange  Commission  during the quarter  ended March 31,
      1997.


                                       12
<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:   May 14, 1997                 EMCON


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

                                       13
<PAGE>


                                                                   Sequentially
Exhibit                                                               Numbered
Number            INDEX TO EXHIBITS                                     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               18
          Registrant,  Columbia  Analytical  Services,  Inc.
          (`CAS"),  Northwest  Trust as  trustee  of the CAS
          Employee Stock  Ownership Trust and certain senior
          management employees of CAS.

 2.5      Stock  Purchase  Agreement  dated  April 30,  1997               43
          among  Registrant,  OWT,  National Earth Products,
          Inc. ("NEP") and the selling stockholders of NEP.

 3.1      Articles    of    Incorporation,    as    amended,               *
          incorporated  by referenc  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").

3.4       Bylaws, as amended, incorporated by reference from               *
          Exhibit 4.2 of the June 1991 10-Q.


                             14
<PAGE>

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

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

10.3      Schedule identifying Agreements pursuant to Salary               81(1)
          Continuation  Plan between  Registrant and certain
          employees.

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 incorporated by               *(1)
          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  by               *(1)
          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 January               *(1)
          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 Registrant               *(1)
          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").


                             14
<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               82
          EMCON to Dennis Grimm and Charles  Gearhart in the
          principal  amounts of $400,798.40 and $399,201.60,
          respectively.


                             15
<PAGE>

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


10.23     Lease Agreement dated April 4, 1997, between EMCON               96
          and Columbia Analytical Services, Inc.

11.1      Computation of Income (Loss) Per Share.                          127

27        Financial Data Schedule, included herein.                        128

*   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.

                             16

<PAGE>