EMCON

                          EMPLOYEE STOCK PURCHASE PLAN

                         (As Amended February 24, 1995)


     1.  Purpose.  The  EMCON  Employee  Stock  Purchase  Plan (the  "Plan")  is
established  to provide  eligible  employees  of EMCON and any current or future
parent or subsidiary corporations of EMCON which the Board of Directors of EMCON
(the "Board")  determines should be included in the Plan (collectively  referred
to as the "Company"),  with an opportunity to acquire a proprietary  interest in
the Company by the purchase of common  stock of EMCON.  (EMCON and any parent or
subsidiary  corporation  designated by the Board as a participating  corporation
shall be  individually  referred  to herein as a  "Participating  Company."  For
purposes of the Plan, a parent corporation and a subsidiary corporation shall be
as defined in sections  424(e) and 424(f) of the Internal  Revenue Code of 1986,
as amended (the "Code").)

     It is intended that the Plan shall qualify as an "employee  stock  purchase
plan"  under  section  423 of the  Code  (including  any  future  amendments  or
replacements of such section), and the Plan shall be so construed.  Any term not
expressly  defined in the Plan but  defined  for  purposes of section 423 of the
Code shall have the same definition herein.

     An employee  participating in the Plan (a "Participant")  may withdraw such
Participant's  accumulated  payroll deductions and direct cash payments (if any)
therein at any time during an Offering Period (as defined  below).  Accordingly,
each  Participant  is, in  effect,  granted  an option  pursuant  to the Plan (a
"Purchase  Right")  which may or may not be  exercised at the end of an Offering
Period and which is intended to qualify as an option described in section 423 of
the Code.

     2. Administration.  The Plan shall be administered by the Board and/or by a
duly  appointed  committee of the Board having such powers as shall be specified
by the  Board.  Any  subsequent  references  to the  Board  shall  also mean the
committee if a committee has been  appointed.  The Board shall have the sole and
absolute  discretion  to  determine  from time to time what parent  corporations
and/or subsidiary corporations shall be Participating  Companies.  All questions
of  interpretation  of the Plan or of any Purchase  Right shall be determined by
the Board and shall be final and binding upon all persons  having an interest in
the Plan and/or any Purchase  Right.  Subject to the provisions of the Plan, the
Board shall  determine  all of the  relevant  terms and  conditions  of Purchase
Rights granted pursuant to the Plan;  provided,  however,  that all Participants
granted  Purchase  Rights  pursuant  to the Plan shall have the same  rights and
privileges  within the meaning of  section 423(b)(5)  of the Code.  All expenses
incurred in connection with the  administration of the Plan shall be paid by the
Company.


                                       


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     3. Share  Reserve.  The maximum  number of shares which may be issued under
the Plan shall be Seven Hundred Twenty-five Thousand (725,000) shares of EMCON's
authorized  but  unissued  common  stock (the  "Shares").  In the event that any
Purchase Right for any reason expires or is cancelled or terminated,  the Shares
allocable  to the  unexercised  portion  of such  Purchase  Right  may  again be
subjected to a Purchase Right. 

     4.  Eligibility.  Any  employee of a  Participating  Company is eligible to
participate  in the  Plan  except  the  following:  

         (a) employees  who have  not  completed  six (6)  months of  continuous
employment with the Company as of the commencement of an Offering Period;

         (b) employees who are customarily employed by the Company for less than
twenty (20) hours a week;

         (c) employees  whose  customary  employment with the Company is for not
more than five (5) months in any calendar year; and

         (d)  employees  who own or hold options to purchase or who, as a result
of participation  in the Plan,  would own or hold options to purchase,  stock of
the Company  possessing  five percent (5%) or more of the total combined  voting
power or value of all  classes of stock of the  Company  within  the  meaning of
section 423(b)(3) of the Code.

     5. Offering Dates.

        (a)  Offering  Periods.  Except as otherwise  set forth below,  the Plan
shall be implemented  by sequential  offerings  (individually  an "Offering") of
twelve (12) months  duration (an "Offering  Period").  An Offering  Period shall
commence on the first day of February  and end on the last day of January of the
following  year. The first Offering Period shall commence on February 1, 1990. A
new employee who first  becomes  eligible to  participate  in the Plan after the
beginning of an Offering  Period may  commence  participation  in such  Offering
Period on the  following  May 1, August 1, or November 1 that first occurs after
becoming  eligible.  A new employee who elects not to participate in the Plan on
the first entry date of the first Offering Period after becoming  eligible shall
not be eligible to  participate in such Offering  Period but may  participate in
any subsequent  Offering provided such employee is still eligible to participate
in the Plan as of the commencement of such subsequent Offering.  Notwithstanding
the  foregoing,  the  Board  may  establish  a  different  term  for one or more
Offerings  and/or different  commencing  and/or ending dates for such Offerings.




                                       19

                                       


The  first  day of an  Offering  Period  shall be the  "Offering  Date" for such
Offering Period. In the event the first and/or last day of an Offering Period is
not a business  day,  the Company  shall  specify the  business day that will be
deemed the first or last day, as the case may be, of the Offering Period.

        (b) Purchase  Periods.  Each  Offering  Period shall  consist of two (2)
consecutive purchase periods of six (6) months duration (the "Purchase Period"),
except for a new employee who  commences  participation  in the Plan on either a
May 1 or November 1, in which case such employee's initial Purchase Period shall
be three (3) months duration.  The last day of each Purchase Period shall be the
"Purchase  Date" for such  Purchase  Period.  Therefore,  for  Offering  Periods
commencing  on the first day of February,  the first  Purchase Date shall be the
last day of July of the same year and the second Purchase Date shall be the last
day of January of the following year.  Notwithstanding the foregoing,  the Board
may establish a different term for one or more Purchase Periods and/or different
commencing dates and/or Purchase Dates for such Purchase  Periods.  In the event
the first  and/or  last day of a  Purchase  Period is not a  business  day,  the
Company  shall  specify the  business  day that will be deemed the first or last
day, as the case may be, of the Purchase Period.

        (c) Governmental  Approval;  Shareholder  Approval.  Notwithstanding any
other provision of the Plan to the contrary, any Purchase Right granted pursuant
to the  Plan  shall be  subject  to (i)  obtaining  all  necessary  governmental
approvals  and/or  qualifications  of the sale and/or  issuance of the  Purchase
Rights and/or the Shares, and (ii) obtaining  shareholder  approval of the Plan.
Notwithstanding  the foregoing,  shareholder  approval shall not be necessary in
order to grant any Purchase  Right  granted on the  Offering  Date of the Plan's
initial  Offering  Period;  provided,  however,  that the  exercise  of any such
Purchase Right shall be subject to obtaining shareholder approval of the Plan.

     6. Participation in the Plan.

        (a)  Initial   Participation.   An  eligible  employee  shall  become  a
participant  in the Plan (a  "Participant")  on the first  Offering  Date  after
satisfying the eligibility  requirements and delivering to the Company not later
than the close of business on the last  business day before such  Offering  Date
(the  "Subscription  Date") an enrollment  agreement  indicating  the employee's
election to  participate  in the Plan and  authorizing  payroll  deductions.  An
eligible employee who does not deliver an enrollment agreement to the Company on
or before  the  Subscription  Date  shall not  participate  in the Plan for that
Offering  Period or for any  subsequent  Offering  Period  unless such  eligible
employee  subsequently  enrolls in the Plan by complying  with the provisions of
paragraph 4 and by filing an enrollment  agreement with the Company on or before
the Subscription Date for such subsequent Offering Period. The Company may, from
time to time, change the Subscription Date as deemed advisable by the Company in
its sole discretion for proper administration of the Plan.


                                       


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        (b) Continued  Participation.  Participation  in the Plan shall continue
until (i) the Participant  terminates employment as provided in paragraph 12, or
(ii) the end of the Offering  Period during which the  Participant  ceases to be
eligible as  provided in  paragraph  4. At the end of an Offering  Period,  each
Participant in such terminating Offering Period shall automatically  participate
in  the  first  subsequent  Offering  Period  according  to the  same  elections
contained in the Participant's  enrollment  agreement effective for the Offering
Period which has just ended,  provided  such  Participant  is still  eligible to
participate in the Plan as provided in paragraph 4. However,  a Participant  may
file an enrollment  agreement with respect to such subsequent Offering Period if
the Participant  desires to change any of the Participant's  elections contained
in the Participant's then effective enrollment agreement.

     7. Right to Purchase Shares.  Except as set forth below, during an Offering
Period each  Participant  in such  Offering  Period shall have a Purchase  Right
consisting  of the right to purchase  that number of whole Shares  arrived at by
dividing  Twenty-Five Thousand Dollars ($25,000) by the fair market value of the
Shares on the Offering Date of such Offering Period.

     8. Purchase  Price.  The purchase  price at which Shares may be acquired at
the end of an  Offering  pursuant  to the  exercise  of all or any  portion of a
Purchase Right granted under the Plan (the "Offering  Exercise  Price") shall be
set by the Board;  provided,  however, that the purchase price shall not be less
than eighty-five percent (85%) of the lesser of (a) the fair market value of the
Shares on the  Offering  Date of such  Offering  Period,  or (b) the fair market
value  of the  Shares  at the  time of  exercise  of all or any  portion  of the
Purchase Right. Unless otherwise provided by the Board prior to the commencement
of an Offering Period, the Offering Exercise Price shall be eighty-five  percent
(85%) of the lesser of (a) the fair market  value of the Shares on the  Offering
Date of such  Offering  Period or (b) the fair market value of the Shares at the
time of exercise of all or any portion of the  Purchase  Right.  The fair market
value of the Shares on the Offering  Date or on the date of exercise will be the
closing price quoted on the National Association of Securities Dealers Automated
Quotations System on such date.

     9. Payment of Purchase  Price.  Shares  which are acquired  pursuant to the
exercise of all or any portion of a Purchase Right for a given  Offering  Period
may be paid  for  only by means of  payroll  deductions  from the  Participant's
Compensation accumulated during the Offering Period. For purposes of the Plan, a
Participant's  "Compensation" with respect to an Offering shall include base pay
and  overtime.  Except as set forth  below,  the  amount of  Compensation  to be
withheld  from a  Participant's  Compensation  during  each pay period  shall be
determined by the Participant's enrollment agreement.


                                       


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        (a) Election to Change  Amount of  Withholding.  During an Offer may not
elect to increase or decrease the amount withheld from his or her  Compensation.
At the beginning of each subsequent  Offering  Period,  a Participant may change
the amount of Compensation to be withheld by delivering to the Company not later
than the Subscription Date a new enrollment agreement.

        (b)   Limitations  on  Payroll   Withholding.   The  amount  of  payroll
withholding  with respect to the Plan for any Participant  during any pay period
shall be at least one percent (1%) but shall not exceed five percent (5%) of the
Participant's  Compensation  for such pay period.  Amounts  shall be withheld in
whole  percentages  only and shall be reduced by any amounts  contributed by the
Participant  and applied to the purchase of Company stock  pursuant to any other
employee stock purchase plan qualifying under section 423 of the Code.

        (c) Payroll Withholding.  Payroll deductions shall commence on the first
payday following the Offering Date and shall continue to the end of the Offering
Period unless sooner altered or terminated as provided in the Plan.

        (d) Participant  Accounts.  Individual  accounts shall be maintained for
each Participant. All payroll deductions from a Participant's Compensation shall
be credited to such account and shall be deposited with the general funds of the
Company.  All payroll deductions  received or held by the Company may be used by
the Company for any corporate purpose.
                  
        (e) No Interest Paid. Interest shall not be paid on sums withheld from a
Participant's Compensation.

        (f) Exercise of Purchase  Right.  On each  Purchase  Date of an Offering
Period,  each Participant whose participation in the Offering has not terminated
on or before such last day shall automatically  acquire pursuant to the exercise
of the  Participant's  Purchase  Right the number of whole Shares  arrived at by
dividing the total amount of the Participant's  accumulated  payroll  deductions
for the Purchase Period by the Offering Exercise Price; provided, however, in no
event shall the number of Shares purchased by the Participant  exceed the number
of Shares  subject  to the  Participant's  Purchase  Right.  No Shares  shall be
purchased on behalf of a Participant whose  participation in the Offering or the
Plan has terminated on or before the date of such exercise.

        (g)  Return  of  Cash  Balance.   Any  cash  balance  remaining  in  the
Participant's  account shall be refunded to the Participant as soon as practical
after the Purchase  Date.  In the event the cash to be returned to a Participant
pursuant to the preceding  sentence is an amount less than the amount  necessary
to purchase a whole Share,  the Company may  establish  procedures  whereby such
cash is maintained in the Participant's  account and applied toward the purchase
of Shares in the subsequent Purchase or Offering Period.


                                       


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        (h) Withholding.  At the time the Purchase Right is exercised,  in whole
or in part,  or at the time  some or all of the  Shares  are  disposed  of,  the
Participant  shall make adequate  provision  for foreign,  federal and state tax
withholding obligations of the Company, if any, which arise upon exercise of the
Purchase Right and/or upon disposition of Shares. The Company may, but shall not
be  obligated  to,  withhold  from the  Participant's  Compensation  the  amount
necessary to meet such withholding obligations.

        (i) Company Established Procedures.  The Company may, from time to time,
establish or change (i) a minimum required  withholding amount for participation
in any Offering,  (ii)  limitations on the frequency and/or number of changes in
the amount  withheld during an Offering,  (iii) an exchange ratio  applicable to
amounts withheld in a currency other than U.S. dollars, (iv) payroll withholding
in excess of or less than the amount  designated  by a  Participant  in order to
adjust  for  delays  or  mistakes  in the  Company's  processing  of  enrollment
agreements,  (v) the date(s)  and manner by which the fair  market  value of the
Shares is determined for purposes of the administration of the Plan, and/or (vi)
such other  limitations or procedures as deemed  advisable by the Company in the
Company's sole discretion  which are consistent with the Plan and section 423 of
the Code.

        (j)  Expiration  of  Purchase  Right.  Any  portion  of a  Participant's
Purchase Right  remaining  unexercised  after the end of the Offering  Period to
which such Purchase Right relates shall expire  immediately upon the end of such
Offering Period.

     10. Limitations on Purchase of Shares; Rights as a Shareholder.

        (a) Fair Market Value Limitation. Notwithstanding any other provision of
the Plan, no Participant shall be entitled to purchase Shares under the Plan (or
any other  employee stock purchase plan within the meaning of section 423 of the
Code which is sponsored by EMCON or a parent or subsidiary corporation of EMCON)
at a rate which  exceeds  $25,000 in fair  market  value,  determined  as of the
Offering Date for each Offering Period (or such other limit as may be imposed by
the Code),  for each calendar year in which the Participant  participates in the
Plan (or any other  employee  stock  purchase plan within the meaning of section
423  of the  Code  which  is  sponsored  by  EMCON  or a  parent  or  subsidiary
corporation of EMCON).


                                       


                                       23



        (b) Allocation of Shares.  In the event the number of Shares which might
be  purchased  by all  Participants  in the Plan  exceeds  the  number of Shares
available  in the Plan,  the  Company  shall make a pro rata  allocation  of the
remaining  Shares  in as  uniform a manner  as shall be  practicable  and as the
Company shall determine to be equitable.

        (c) Rights as a Shareholder  and Employee.  A Participant  shall have no
rights as a shareholder by virtue of the Participant's participation in the Plan
until the date of the  issuance  of a stock  certificate  for the  Shares  being
purchased  pursuant to the  exercise of the  Participant's  Purchase  Right.  No
adjustment shall be made for cash dividends or distributions or other rights for
which the  record  date is prior to the date such stock  certificate  is issued.
Nothing  herein  shall  confer upon a  Participant  any right to continue in the
employ of the Company or  interfere  in any way with any right of the Company to
terminate the Participant's employment at any time.

     11.  Withdrawal  from the Plan. A Participant may withdraw from the Plan by
signing a written  notice of  withdrawal  on a form  provided by the Company for
such purpose and delivering such notice to the Company. Withdrawals made after a
Purchase  Date of an Offering  Period  shall not affect  shares  acquired by the
Participant on a Purchase Date. In the event a Participant voluntarily elects to
withdraw from the Plan, the Participant may not resume participation in the Plan
during the same Offering Period, but may participate in any subsequent  Offering
under the Plan by again  satisfying the requirements of paragraph 6. The Company
may impose, from time to time, a requirement that the notice of withdrawal be on
file with the Company for a reasonable  period prior to the effectiveness of the
Participant's withdrawal from the Plan.

     12.  Termination of Employment.  Termination of a Participant's  employment
with the Company for any reason, including retirement or death or the failure of
a Participant to remain an employee  eligible to participate in the Plan,  shall
terminate the Participant's participation in the Plan immediately. A Participant
whose  participation  has  been so  terminated  may  again  become  eligible  to
participate in the Plan by again satisfying the requirements of paragraphs 4 and
6.

     13. Repayment of Payroll Deductions.  In the event a Participant's interest
in the Plan or any Offering  therein is terminated  for any reason,  the balance
held in the  Participant's  account shall be returned as soon as practical after
such termination to the Participant (or, in the case of the Participant's death,
to the Participant's legal  representative) and all of the Participant's  rights
under the Plan shall  terminate.  Such account balance may not be applied to any
other  Offering  under the Plan. No interest shall be paid on sums returned to a
Participant pursuant to this paragraph 13.


                                       


                                       24



     14.  Transfer of Control.  A "Transfer of Control"  shall be deemed to have
occurred in the event any of the  following  occurs.with  respect to the Control
Company. For purposes of applying this paragraph 14, the "Control Company" shall
mean the Participating Company whose stock is subject to the Purchase Right.
                  
        (a) the direct or indirect sale or exchange by the  shareholders  of the
Control Company of all or substantially  all of the stock of the Control Company
where the  shareholders  of the Control  Company before such sale or exchange do
not  retain,  directly  or  indirectly,  at least a majority  of the  beneficial
interest in the voting stock of the Control Company;

        (b) a merger in which the  shareholders  of the Control  Company  before
such merger do not retain,  directly or  indirectly,  at least a majority of the
beneficial interest in the voting stock of the Control Company; or

        (c) the sale,  exchange,  or transfer of all or substantially all of the
Control Company's assets (other than a sale, exchange, or transfer to one (1) or
more  corporations  where the  shareholders  of the Control  Company before such
sale, exchange, or transfer retain, directly or indirectly,  at least a majority
of the beneficial  interest in the voting stock of the  corporation(s)  to which
the assets were transferred).

     In the event of a Transfer of Control,  the Board, in its sole  discretion,
shall either (i) provide that  Purchase  Rights  granted under the Plan shall be
fully  exercisable to the extent of each  Participant's  account balance for the
Offering  Period as of a date prior to the Transfer of Control,  as the Board so
determines  or (ii)  arrange  with  the  surviving,  continuing,  successor,  or
purchasing  corporation,  as the case may be, that such  corporation  assume the
Company's  rights and  obligations  under the Plan.  All  Purchase  Rights shall
terminate effective as of the date of the Transfer of Control to the extent that
the  Purchase  Right is  neither  exercised  as of the date of the  Transfer  of
Control nor assumed by the surviving, continuing, successor, or purchasing
corporation, as the case may be.

     15.  Capital  Changes.  In the event of changes in the common  stock of the
Company due to a stock split, reverse stock split, stock dividend,  combination,
reclassification,  or like  change in the  Company's  capitalization,  or in the
event of any merger, sale or other reorganization, appropriate adjustments shall
be made by the Company in the Plan's share reserve, the number of Shares subject
to a Purchase Right and in the purchase price per share.

     16.  Non-Transferability.  A Purchase  Right may not be  transferred in any
manner  otherwise than by will or the laws of descent and distribution and shall
be exercisable during the lifetime of the Participant only by the Participant.


                                       


                                       25



     17.   Reports.   Each   Participant  who  exercised  all  or  part  of  the
Participant's  Purchase  Right for a Purchase  Period  shall  receive as soon as
practical  after  the  last  day of  such  Purchase  Period  a  report  of  such
Participant's  account setting forth the total payroll  deductions  accumulated,
the number of Shares  purchased and the remaining cash balance to be refunded or
retained in the Participant's account pursuant to paragraph 9(g), if any.

     18. Plan Term.  This Plan shall continue  until  terminated by the Board or
until all of the Shares reserved for issuance under the Plan have been issued.
         
     19.  Restriction on Issuance of Shares.  The issuance of shares pursuant to
the  Purchase  Right  shall  be  subject  to  compliance   with  all  applicable
requirements  of  federal  or state law with  respect  to such  securities.  The
Purchase Right may not be exercised if the issuance of shares upon such exercise
would constitute a violation of any applicable  federal or state securities laws
or other law or  regulations.  In addition,  no Purchase  Right may be exercised
unless  (i) a  registration  statement  under  the  Securities  Act of 1933,  as
amended,  shall at the time of exercise of the Purchase  Right be in effect with
respect to the shares  issuable upon exercise of the Purchase  Right, or (ii) in
the opinion of legal counsel to the Company,  the shares  issuable upon exercise
of the  Purchase  Right  may be  issued  in  accordance  with  the  terms  of an
applicable  exemption  from the  registration  requirements  of said  Act.  As a
condition  to the exercise of the  Purchase  Right,  the Company may require the
Participant to satisfy any qualifications  that may be necessary or appropriate,
to evidence  compliance  with any  applicable  law or regulation and to make any
representation  or warranty  with  respect  thereto as may be  requested  by the
Company.

     20. Legends. The Company may at any time place legends or other identifying
symbols referencing any applicable federal and/or state securities  restrictions
and any provision convenient in the administration of the Plan on some or all of
the  certificates  representing  shares of stock  issued  under  the  Plan.  The
Participant  shall,  at the  request  of the  Company,  promptly  present to the
Company any and all  certificates  representing  shares  acquired  pursuant to a
Purchase Right in the  possession of the  Participant in order to effectuate the
provisions of this paragraph.

     21. Transfer  Restrictions.  The Company, in its absolute  discretion,  may
impose such restrictions on the  transferability  of the shares purchasable upon
the  exercise  of a  Purchase  Right  as  it  deems  appropriate  and  any  such
restriction shall be set forth in the respective enrollment agreement and may be
referred to on the certificates  evidencing such shares. The Company may require
the employee to give the Company  prompt notice of any  disposition of shares of
stock acquired by exercise of a Purchase Right within two years from the date of
granting  such  Purchase  Right or one year  from the date of  exercise  of such
Purchase Right. The Company may direct that the certificates  evidencing  shares
acquired  by  exercise of a Purchase  Right  refer to such  requirement  to give
prompt notice of disposition.


                                       


                                       26



     22.  Amendment or  Termination of the Plan. The Board may at any time amend
or  terminate  the Plan,  except  that (i) such  termination  shall  not  affect
Purchase  Rights  previously  granted  under the Plan except as permitted by the
Plan,  and (ii) no amendment may adversely  affect a Purchase  Right  previously
granted under the Plan (except to the extent  permitted by the Plan or as may be
necessary to qualify the Plan as an employee  stock  purchase  plan  pursuant to
section 423 of the Code). In addition, an amendment to the Plan must be approved
by the  shareholders  of the  Company,  within the meaning of section 423 of the
Code,  within  twelve (12)  months of the  adoption  of such  amendment  if such
amendment  would  authorize  the sale of more  shares  than are  authorized  for
issuance under the Plan or would change the definition of the corporations  that
may be  designated  by the Board as a  corporation  the  employees  of which are
eligible to participate in the Plan.  Notwithstanding any other provision of the
Plan to the  contrary,  the  Board may at any time  amend  the  Plan;  provided,
however,  that if such  amendment  affects the rights and privileges of Purchase
Rights to be  offered  under  the Plan,  each  Participant  with an  outstanding
Purchase Right shall have the right to exercise such outstanding  Purchase Right
on the effective  date of the amendment and to  participate  in the Plan for the
remaining  term of such  outstanding  Purchase  Right  pursuant to the terms and
conditions of the Plan as amended.  If in accordance with the preceding sentence
a Participant elects to exercise such outstanding Purchase Right and to commence
participation  in the Plan as amended on the effective  date of such  amendment,
the  Participant  shall be deemed to have received a new Purchase  Right on such
effective  date, and such effective date shall be deemed to be the Offering Date
for such new Purchase Right.

     IN WITNESS WHEREOF, the undersigned Secretary of the Company certifies that
the foregoing  EMCON  Employee Stock Purchase Plan was duly adopted by the Board
of  Directors  of the Company on November  15, 1989 and last amended on February
24, 1995.




                                               








                                       


                                       27



                                  Plan History
                                  ------------


November 15, 1989      Board of Directors adopted the Plan with a share reserve
                       of 250,000 shares.

May 30, 1990           The shareholders approved the Plan with a share reserve
                       of 250,000 shares.

August 6, 1991         The Board approved a 3-2 stock split of the Common Stock
                       of the Company which increased the initial 250,000 share
                       reserve to 375,000 shares.

February 24, 1995      The Board amended the Plan to increase the share reserve
                       by 350,000 shares from 375,000 shares to 725,000 shares.

May 24, 1995           The shareholders approved the share reserve increase.



                                      


                                       28




                                ENROLLMENT FORM

                                     EMCON
                          EMPLOYEE STOCK PURCHASE PLAN


     As an employee of EMCON or one of its wholly owned  subsidiaries,  I hereby
elect to  participate  in the Employee Stock Purchase Plan (the "Plan") of EMCON
("the  "Company")  and enroll to purchase  shares of the Company's  common stock
(the "Shares") as determined in accordance  with the terms of the Stock Purchase
Plan.

     I hereby authorize  payroll  deductions in the amount of % (1% to 5%) of my
base pay and any overtime from each paycheck  throughout  the "Offering  Period"
(as defined in the Plan) in  accordance  with the terms of the Plan.  The amount
deducted  each pay period must be between 1% and 5% of base pay and any overtime
and must be  stated  in whole  percentages.  I  understand  that  these  payroll
deductions will be accumulated for the purchase of shares of common stock of the
Company at the applicable purchase price determined in accordance with the Plan.
I further  understand  that,  except as otherwise set forth in the Plan,  shares
will be purchased for me  automatically  on the last day of each purchase period
unless I  withdraw  from the Plan by giving  written  notice to the  Company  or
unless I terminate  employment or otherwise become  ineligible to participate in
the Plan.

     I  understand  that I will  automatically  participate  in each  subsequent
Offering  Period  under the Plan  until  such time as I file with the  Company a
notice of withdrawal from the Plan or I terminate employment or otherwise become
ineligible to participate in the Plan.

     Shares  purchased  for me under  the Plan  should be issued in the name set
forth below.  I understand  that Shares may be issued either in my name alone or
together  with my spouse.  If a spouse is listed,  please  indicate  whether the
Shares should be issued in joint tenancy or as community property.

     NAME:  _________________________________________                   

     ADDRESS: _______________________________________
              _______________________________________ 


     MY SOCIAL SECURITY NUMBER: _____________________                         

     I am familiar with the terms and provisions of the Plan and hereby agree to
participate in the Plan subject to all of its terms and provisions. I understand
that the Board of Directors of the Company  reserves the right to amend the Plan
and my right to purchase stock under the Plan as may be necessary to qualify the


                                      


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Plan as an  employee  stock  purchase  plan as  defined  in  section  423 of the
Internal Revenue Code of 1986, as amended.  I understand that the  effectiveness
of this  subscription  agreement is dependent upon my eligibility to participate
in the Plan.

Date:___________________                          Signature:___________________



                                       


                                       30


                              NOTICE OF WITHDRAWAL

                                     EMCON
                          EMPLOYEE STOCK PURCHASE PLAN

     I hereby elect to withdraw from the current  offering (the  "Offering")  to
purchase the common  stock of EMCON (the  "Company")  under the  Employee  Stock
Purchase Plan (the "Plan"),  and I request that all payroll deductions  credited
to my account  under the Plan with  respect to the  Offering  (if any),  and not
previously  used to purchase  shares of common  stock of the  Company  under the
Plan,  be paid to me as soon as is practical.  I understand  that this Notice of
Withdrawal automatically terminates my interest in the Offering.

     As to participation in future offerings of stock under the Plan, I elect as
follows:

________          I elect to participate in future offerings under the Plan.

                  I  understand  that by making the  election  set forth above I
                  will  automatically  participate in each  subsequent  Offering
                  under the Plan  until  such time as I file with the  Company a
                  notice  of  withdrawal  from the  Plan or any such  subsequent
                  offering on such form as may be established  from time to time
                  by the Company or I terminate  employment or otherwise  become
                  ineligible to participate in the Plan.

________          I elect not to participate in future offering under the Plan.

                  I  understand  that by making the  election  set forth above I
                  terminate my interest in the Plan and that no further  payroll
                  deductions  will be made unless I elect in accordance with the
                  Plan to become a  participant  in another  offering  under the
                  Plan.

________          I understand  that if no election is made as to  participation
                  in future  offerings  under the Plan, I will be deemed to have
                  elected to participate in such offerings.


Date:_____________________                      Signature:_____________________



                                       



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