EXHIBIT 10.50B

                    FOURTH AMENDMENT TO THE CREDIT AGREEMENT

          This Amendment is made and entered into as of the 15th day of October,
2002,  by and between WELLS FARGO BANK, NATIONAL ASSOCIATION, successor to First
Security Bank ("Bank"), and AMERICAN ECOLOGY CORPORATION, a Delaware corporation
("Borrower").

                                R E C I T A L S

          A.     Borrower  and Bank  entered into  a Credit Agreement,  dated as
of August 17, 2000 (as amended, modified, or supplemented from time to time, the
"Credit  Agreement").

          B.     Borrower has asked Bank to amend the Credit Agreement to extent
the  maturity  date  and  adjust  the  interest  rate.

          C.     Bank is willing to amend the Credit Agreement upon the terms
and  conditions  of  this  Amendment.

                                A M E N D M E N T

          NOW, THEREFORE, the parties agree as follows.

          1.     DEFINITIONS

          Except as specifically defined otherwise in this Amendment, all of the
terms  herein  shall have the same meaning as contained in the Credit Agreement.

          2.     AMENDMENTS

               A.     AMENDMENTS TO ARTICLE 1 - DEFINITIONS.

                    (i)     The definition of "Commitment Amount" in Section 1.1
of  the  Credit  Agreement  is  amended to decrease the amount to $6,000,000 and
shall  provide  in  its  entirety  as  follows:

          "COMMITMENT AMOUNT" means Six Million Dollars ($6,000,000), less
     (i)the  aggregate  stated  amount of all Letters of Credit then outstanding
     and  available  for  drawing, and (ii) the aggregate amount of unreimbursed
     drawings  on  Letters  of  Credit.

                    (ii)     The definition of "Guarantor" in Section 1.1 of the
Credit Agreement is amended to reflect the dissolution of several guarantors and
shall  provide  in  its  entirety  as  follows:


FOURTH AMENDMENT TO CREDIT AGREEMENT - 1

          "GUARANTOR"  means,  jointly  and  severally, US Ecology, Inc., a
     California  corporation,  Texas Ecologists, Inc., a Texas corporation,
     American  Ecology  Recycle  Center,  Inc.,  a  Delaware  corporation,
     American  Ecology  Environmental  Services  Corporation,  a  Texas
     corporation,  American  Ecology  Management  Corporation,  a  Delaware
     corporation,  American Ecology Services Corp., a Delaware corporation,
     and  US  Ecology  Idaho,  Inc.,  a  Delaware  corporation.

                    (iii)     The  definition  of  "Letter  of Credit Commitment
Amount"  in  Section 1.1 of the Credit Agreement is amended to adjust the amount
of  Revolving  Loans  that will reduce the Letter of Credit Commitment Amount to
reflect  the decrease in the Commitment Amount and shall provide in its entirety
as  follows:

          "LETTER  OF CREDIT COMMITMENT AMOUNT" means Three Million Dollars
     ($3,000,000),  less the amount of the outstanding principal balance of
     the  Revolving  Loans in excess of Three Million Dollars ($3,000,000).

                    (iv)     The definition of "Maturity Date" in Section 1.1 of
the  Credit  Agreement is amended to extend the date to June 15, 2004, and shall
provide  in  its  entirety  as  follows:

          "MATURITY  DATE"  means June 15, 2004, or such other date as Bank
     and  Borrower  may  agree  upon  in  writing  from  time  to  time.

               B.     AMENDMENTS TO ARTICLE 2 - LOANS AND TERMS OF PAYMENT.

                    (i)     Subsection 2.1.2  of the Credit Agreement is amended
to  modify  the  interest rate for the Revolving Loans, and shall provide in its
entirety  as  follows:

               2.1.2 INTEREST  ON THE REVOLVING LOANS. Each Revolving Loan shall
     be a Prime Loan or a LIBOR Loan, as selected by Borrower in accordance with
     the  terms  of  this  Agreement.

                    2.1.2.1     Each  Revolving  Loan that is a Prime Loan shall
     bear  interest  at  a  fluctuating  per  annum rate equal to the Prime Rate
     increased by the applicable Prime Margin set forth below. Bank's Prime Rate
     may  change  from  time  to time, and the interest payable will continue to
     fluctuate at the rate as stated herein. Any changes to the Prime Rate shall
     become  effective without prior notice to Borrower on the date on which the
     Prime  Rate  changes.

                    2.1.2.2     Each  Revolving  Loan that is a LIBOR Loan shall
     bear  interest  at a fluctuating per annum rate equal to the Adjusted LIBOR
     Interest  Rate for the applicable Interest Period, as quotes are available,
     increased  by  the  applicable LIBOR Margin set forth below. Any changes to
     the  LIBOR Margin shall not apply to LIBOR Loans outstanding or requested
     on  the  date  the  LIBOR  Margin  is  adjusted.


FOURTH AMENDMENT TO CREDIT AGREEMENT - 2

                    2.1.2.3     The  Prime  Margins,  the  LIBOR  Margins,  the
     Commitment  Margins,  and  the  L/C  fees  are  as  follows:

         FUNDED DEBT RATIO      PRIME    LIBOR   COMMITMENT   L/C FEE
     ------------------------  -------  -------  -----------  --------
     less than 1.00:1.00          0.0%    2.00%        0.15%     1.25%
     ------------------------  -------  -------  -----------  --------
     less than 2.00: 1.00 but   0.125%    2.25%        0.25%    1.375%
     greater than or equal to
     1.00:1.00
     ------------------------  -------  -------  -----------  --------
     less than 3.00: 1.00 but    0.25%    2.50%        0.30%     1.50%
     greater than or equal to
     2.00:1.00
     ------------------------  -------  -------  -----------  --------
     less than 3.50: 1.00 but    0.50%    2.75%        0.40%     1.75%
     greater than or equal to
     3.00:1.00
     ------------------------  -------  -------  -----------  --------
     less than or equal to       1.00%    3.25%        0.50%     2.00%
     4.00: 1.00 but greater
     than or equal to
     3.50:1.00
     ------------------------  -------  -------  -----------  --------
     greater than 4.00: 1.00   1.00%*   3.25%*         0.50%     2.00%
     ------------------------  -------  -------  -----------  --------
*Plus increase for an Event of Default pursuant to Section 2.5, if applicable.

                    2.1.2.4     The  Prime  Margin,  LIBOR  Margin,  Commitment
     Margin,  and  L/C  Fee shall be based upon the Borrower's Funded Debt Ratio
     (defined  in  paragraph 2.1.2.5) determined on a rolling four quarter basis
     from the Borrower's financial statements delivered to Bank and adjusted, if
     necessary,  on  the  first  day of the second month after Bank's receipt of
     financial  statements  that  show  an  adjustment  is  necessary.

                    2.1.2.5     Borrower's  Funded Debt Ratio shall be the ratio
     of  Borrower's Funded Debt to EBITDA. The term "Funded Debt" shall mean, as
     of  the  date  of  determination as applied to Borrower, the sum of (i) all
     indebtedness  of  Borrower  owing  to  third  parties  for  money borrowed,
     including capitalized leases of Borrower having a final maturity of one (1)
     year  or  more  from  the  date  of creation (including that portion of the
     principal  of  such  indebtedness  due within one (1) year from the date of
     such  determination),  (ii) any indebtedness of the Borrower having a final
     maturity  within  one  (1)  year  from  such  date  which may be renewed or
     extended at the option of the Borrower for more than one (1) year from such
     date,  (iii)  the  outstanding  balance  of  the  Revolving Loans, (iv) all
     obligations  for  the  deferred  purchase  price of any property or assets,
     including, without limitation, operating leases for such purpose (excluding
     trade payables), (v) all obligations for deferred closure/post closure, and
     (vi)  all  obligations  of  Borrower  created  or  arising  with respect to
     property  or  assets acquired under any conditional sales contract or other
     title  retention  agreement  or  incurred  as financing, less the amount of
     Borrower's short term investments as of the date of determination. The term
     "EBITDA"  shall  mean,


FOURTH AMENDMENT TO CREDIT AGREEMENT - 3

     for  any  period,  as  applied to Borrower, the sum of Borrower's earnings,
     excluding  any  extraordinary  and nonoperating income, before (a) interest
     expense,  (b) depreciation, (c) dividends, (d) taxes, (e) amortization, and
     (f)  other  noncash  charges.

                    (ii)     Subsection 2.6.4 of the Credit Agreement is amended
to have the interest for all Loans  computed on the basis of a 360-day year, and
shall  provide  in  its  entirety  as  follows:

               2.6.4     The actual interest to be charged on the Loans shall be
     calculated  daily  on the outstanding balance for the actual number of days
     elapsed  on  the basis of a year consisting of 360 days. Should the rate of
     interest  exceed  that allowed by law, the applicable rate of interest will
     be  the  maximum  rate  of  interest lawfully allowed. The principal amount
     outstanding  on  which  the  interest  rate(s)  shall  be  charged shall be
     determined from the Bank's records, which shall at all times be conclusive,
     absent  manifest  error.

               C.     AMENDMENTS TO ARTICLE 5 - AFFIRMATIVE COVENANTS.

                    (i)     Subsection  5.8.2 of the Credit Agreement is amended
to  require  a  Borrowing  Base Certificate only when the outstanding borrowings
exceed  60%  of  Borrower's  net  accounts  receivable, and shall provide in its
entirety  as  follows:

               5.8.2     BORROWING  BASE  CERTIFICATE. Borrower shall furnish to
     Bank on or before the 20th day of each month reporting as of the end of the
     last  Business  Day  of  the  prior month statements of accounts receivable
     aging  and  a  certificate  setting  forth  information with respect to the
     Borrowing Base, executed and certified as accurate by an authorized officer
     of Borrower. The certificate shall be in substantially the form attached to
     the  Agreement as EXHIBIT 5.8.2 or such other form as Borrower and Bank may
     agree  upon  in writing. Borrower shall not be required to furnish Bank the
     statements  and  certificates  required by this subsection on any reporting
     date  if  the  aggregate  total  of  the Revolving Loans and the Letters of
     Credit  on  such  date  does not exceed 60% of the amount of Borrower's net
     accounts  receivable  as  reported  in the most recent SEC Report or Annual
     Financial  Statements  of  Borrower  furnished  to  Bank.

                    (ii)     Subsection 5.8.8 of the Credit Agreement is amended
to  establish  an absolute date by which a coy of Borrower's 1OQ reports must be
furnished  to  Bank,  and  shall  provide  in  its  entirety  as  follows:

               5.8.8     SEC REPORTS.  Borrower shall furnish to Bank as soon as
     possible  and  in  any event within five (5) Business Days after the filing
     thereof,  copies  of  all  regular,  periodic, and special reports, and all
     registration  statements  that  the


FOURTH AMENDMENT TO CREDIT AGREEMENT - 4

     Borrower  or  any  Subsidiary  files  with  the  Securities  and  Exchange
     Commission  or any governmental authority that may be substituted therefor,
     or  with  any  national securities exchange, including, without limitation,
     10Q, 10K, and 8K reports. Notwithstanding anything in this Agreement to the
     contrary,  Borrower  furnish  Bank  with a copy of Borrower's 10Q report no
     later  than  45  days  after  the  end  of  each  fiscal  quarter.

               D.     AMENDMENTS TO ARTICLE 7 - FINANCIAL COVENANTS.

                    Article 7 of the Credit Agreement is amended by the addition
of  a  new Section 7.4 to establish a maximum Funded Debt Ratio to be maintained
by  Borrower,  and  the  section  shall  provide  in  its  entirety  as follows:

          7.4     FUNDED DEBT RATIO.

          Borrower  shall  maintain  at  the end of each fiscal quarter and each
     fiscal  year  a  Funded Debt Ratio (as defined in Paragraph 2.1.2.5) of not
     greater  than  4.00  to  1.00.

               E.     AMENDMENTS TO ARTICLE 9 - BANK'S RIGHTS AND REMEDIES.

                    Article 9 of the Credit Agreement is amended by the addition
of  a  new Section 9.4 to establish procedure for resolution of disputes through
arbitration,  and  the  section  shall  provide  in  its  entirety  as  follows:

          9.4     ARBITRATION.

               9.4.1     ARBITRATION.  The  parties  shall,  upon  demand by any
     party, submit to binding arbitration all claims, disputes and controversies
     between or among them (and their respective employees, officers, directors,
     attorneys,  and  other  agents),  whether  in  tort,  contract or otherwise
     arising  out  of  or  relating  to  in  any  way (i) the Loans and the Loan
     Documents  and  their  negotiation,  execution,  collateralization,
     administration,  repayment,  modification,  extension,  substitution,
     formation,  inducement,  enforcement,  default  or  termination;  or  (ii)
     requests  for  additional  credit.

               9.4.2     GOVERNING RULES.  Any  arbitration  proceeding will (i)
     proceed  in  a  location  in  Idaho  selected  by  the American Arbitration
     Association ("AAA"); (ii) be governed by the Federal Arbitration Act (Title
     9 of the United States Code), notwithstanding any conflicting choice of law
     provision  in  any  of  the  documents  between  the  parties; and (iii) be
     conducted  by  the  AAA,  or  such other administrator as the parties shall
     mutually  agree  upon,  in  accordance  with  the  AAA's commercial dispute
     resolution  procedures,  unless  the  claim  or  counterclaim  is  at least
     $1,000,000.00  exclusive of claimed interest, arbitration fees and costs in
     which  case the arbitration shall be conducted in accordance with the AAA's
     optional  procedures


FOURTH AMENDMENT TO CREDIT AGREEMENT - 5

     for  large,  complex commercial disputes (the commercial dispute resolution
     procedures  or  the  optional  procedures  for  large,  complex  commercial
     disputes to be referred to, as applicable, as the "Rules"). If there is any
     inconsistency  between  the  terms  hereof  and  the  Rules,  the terms and
     procedures  set  forth herein shall control. Any party who fails or refuses
     to  submit  to arbitration following a demand by any other party shall bear
     all  costs  and  expenses  incurred  by  such  other  party  in  compelling
     arbitration  of any dispute. Nothing contained herein shall be deemed to be
     a  waiver  by  any  party  that is a bank of the protections afforded to it
     under  12  U.S.C.  Sec.91  or  any  similar  applicable  state  law.

               9.4.3     NO  WAIVER  OF PROVISIONAL REMEDIES,   Self-Help  and
     Foreclosure.  The  arbitration  requirement does not limit the right of any
     party  to  (i) foreclose against real or personal property collateral; (ii)
     exercise  self-help  remedies  relating  to  collateral  or  proceeds  of
     collateral  such  as setoff or repossession; or (iii) obtain provisional or
     ancillary  remedies  such as replevin, injunctive relief, attachment or the
     appointment  of  a  receiver,  before  during  or after the pendency of any
     arbitration  proceeding. This exclusion does not constitute a waiver of the
     right  or  obligation  of any party to submit any dispute to arbitration or
     reference  hereunder,  including  those  arising  from  the exercise of the
     actions  detailed  in  sections  (i),  (ii)  and  (iii)  of this paragraph.

               9.4.4     ARBITRATOR QUALIFICATIONS AND POWERS.   Any arbitration
     proceeding in which the amount in controversy is $5,000,000.00 or less will
     be  decided by a single arbitrator selected according to the Rules, and who
     shall  not  render  an  award of greater than $5,000,000.00. Any dispute in
     which  the  amount in controversy exceeds $5,000,000.00 shall be decided by
     majority  vote  of a panel of three arbitrators; provided however, that all
     three  arbitrators  must  actively  participate  in  all  hearings  and
     deliberations.  The  arbitrator  will be a neutral attorney licensed in the
     State of Idaho or a neutral retired judge of the state or federal judiciary
     of  Idaho,  in  either  case  with a minimum of ten years experience in the
     substantive  law  applicable  to  the  subject  matter of the dispute to be
     arbitrated.  The  arbitrator  will  determine  whether  or  not an issue is
     arbitratable  and  will  give  effect  to  the  statutes  of  limitation in
     determining  any  claim.  In any arbitration proceeding the arbitrator will
     decide (by documents only or with a hearing at the arbitrator's discretion)
     any pre-hearing motions which are similar to motions to dismiss for failure
     to  state a claim or motions for summary adjudication. The arbitrator shall
     resolve  all  disputes  in accordance with the substantive law of Idaho and
     may  grant  any  remedy or relief that a court of such state could order or
     grant  within the scope hereof and such ancillary relief as is necessary to
     make effective any award. The arbitrator shall also have the power to award
     recovery  of all costs and fees, to impose sanctions and to take such other
     action  as  the arbitrator deems necessary to the same extent a judge could
     pursuant  to the Federal Rules of Civil Procedure, the Idaho Rules of Civil
     Procedure  or other applicable law. Judgment upon the award rendered by the
     arbitrator may be entered in any court having jurisdiction. The institution
     and  maintenance  of  an  action  for


FOURTH AMENDMENT TO CREDIT AGREEMENT - 6

     judicial  relief  or pursuit of a provisional or ancillary remedy shall not
     constitute  a waiver of the right of any party, including the plaintiff, to
     submit  the controversy or claim to arbitration if any other party contests
     such  action  for  judicial  relief.

               9.4.5     DISCOVERY.  In  any  arbitration  proceeding  discovery
     will  be  permitted  in  accordance  with the Rules. All discovery shall be
     expressly  limited  to  matters  directly  relevant  to  the  dispute being
     arbitrated  and  must be completed no later than 20 days before the hearing
     date  and  within  180  days of the filing of the dispute with the AAA. Any
     requests  for  an  extension  of  the  discovery  periods, or any discovery
     disputes,  will  be subject to final determination by the arbitrator upon a
     showing  that  the  request  for  discovery  is  essential  for the party's
     presentation  and  that  no  alternative means for obtaining information is
     available.

               9.4.6     CLASS  PROCEEDINGS  AND CONSOLIDATIONS.  The resolution
     of  any  dispute  arising  pursuant to the terms of this Agreement shall be
     determined  by a separate arbitration proceeding and such dispute shall not
     be  consolidated  with  other disputes or included in any class proceeding.

               9.4.7     PAYMENT OF ARBITRATION COSTS AND FEES.   The arbitrator
     shall  award  all  costs  and  expenses  of  the  arbitration  proceeding.

               9.4.8     REAL  PROPERTY  COLLATERAL.  Notwithstanding  anything
     herein to the contrary, no dispute shall be submitted to arbitration if the
     dispute  concerns  indebtedness secured directly or indirectly, in whole or
     in  part,  by any real property unless (i) the holder of the mortgage, lien
     or  security  interest  specifically  elects in writing to proceed with the
     arbitration,  or  (ii)  all  parties to the arbitration waive any rights or
     benefits  that  might  accrue  to  them by virtue of the single action rule
     statute of Idaho, thereby agreeing that all indebtedness and obligations of
     the  parties, and all mortgages, liens and security interests securing such
     indebtedness  and  obligations,  shall  remain fully valid and enforceable.

               9.4.9     MISCELLANEOUS.  To  the maximum extent practicable, the
     AAA,  the  arbitrators  and  the  parties shall take all action required to
     conclude  any  arbitration  proceeding within 180 days of the filing of the
     dispute  with  the  AAA.  No  arbitrator  or  other party to an arbitration
     proceeding  may  disclose the existence, content or results thereof, except
     for  disclosures  of information by a party required in the ordinary course
     of  its  business  or  by  applicable  law  or regulation. If more than one
     agreement  for arbitration by or between the parties potentially applies to
     a  dispute,  the  arbitration  provision  most directly related to the Loan
     Documents  or  the  subject  matter  of  the  dispute  shall  control. This
     arbitration provision shall survive termination, amendment or expiration of
     any  of  the  Loan  Documents  or  any  relationship  between  the parties.


FOURTH AMENDMENT TO CREDIT AGREEMENT - 7

          3.     CONDITIONS PRECEDENT

          As  conditions  precedent to Bank's obligation to extend the financial
accommodations  provided  for  in  this  Amendment,  Borrower  shall execute and
deliver,  or  cause to be executed and delivered, to Bank, in form and substance
satisfactory  to  Bank  and  its  counsel,  the  following:

               A.     REVOLVING NOTE.

               The  new  Revolving  Note  required  by  this  Amendment  in
substantially the form attached as Exhibit 3A, duly executed by Borrower.

               B.     EVIDENCE OF ALL CORPORATE ACTION BY BORROWER.

               Certified  copies  of  all  corporate  action  taken  by Borrower
authorizing its execution and delivery of this Amendment and each other document
to be delivered pursuant to this Amendment and its performance of its agreements
thereunder.

               C.     CERTIFICATES OF EXISTENCE.

               Certificates  of  good  standing  or  existence  that  Bank  may
reasonably  require  showing that Borrower is in good standing under the laws of
the  state  of  its  incorporation.

               D.     PUBLIC RECORD SEARCHES.

               Uniform Commercial Code financing statement searches, federal and
state  income  tax  lien  searches,  judgment  or  litigation searches, or other
similar  searches  that Bank may reasonably require and in such form as Bank may
reasonably  require.

               E.     PAYMENT OF LOAN AMENDMENT FEE.

               Payment  of  the  Loan  Amendment Fee as required by Section 4 of
this  Amendment.

               F.     ADDITIONAL DOCUMENTATION.

               Such  other  approvals,  opinions,  or  documents  as  Bank  may
reasonably request.

          4.     LOAN AMENDMENT FEE.

          Upon  the  execution of this Amendment, Borrower shall pay Bank a loan
amendment  fee  of Twelve Thousand Dollars ($12,000.00). The fee shall represent
an  unconditional payment to Bank in consideration of Bank's agreement to extend
financial  accommodations  to  Borrower  pursuant  to  this  Amendment.


FOURTH AMENDMENT TO CREDIT AGREEMENT - 8

          5.     REAFFIRMATION OF LOAN DOCUMENTS.

          Borrower  acknowledges and reaffirms all existing security agreements,
financing  statements,  and  any other documents executed in connection with the
Credit  Agreement. Borrower further acknowledges and agrees that the Obligations
shall  be  secured  by  all  collateral  to  be  granted by Borrower to secure a
proposed  term  loan  from  Bank  to  Borrower.

          6.     BORROWER'S COVENANTS, REPRESENTATIONS, AND WARRANTIES.

          In  order to induce Bank to enter into this Amendment and to amend the
Credit  Agreement  in  the  manner  provided  herein,  Borrower acknowledges and
reaffirms  as  true, correct, and complete in all material respects on and as of
the  date  of this Amendment all covenants, representations, and warranties made
by  Borrower  in  the  Credit Agreement and the other Loan Documents to the same
extent  as  though  made  on  and as of the date of execution of this Amendment.
Borrower  represents  and warrants that the execution, delivery, and performance
by  the  Borrower  of  this  Amendment has been duly authorized by all necessary
corporate  action.  Borrower  further  represents and warrants that there are no
Events  of  Default  or  facts which constitute, or with the passage of time and
without  change  will  constitute, an Event of Default under the Loan Documents.
Borrower  further  represents  that there has been no material adverse change in
Borrower's  business  or  financial  condition  from  that reflected in the most
recent  of  Borrower's  financial  statements  that have been delivered to Bank.
Borrower  further  represents and warrants that Borrower has no claims or causes
of action of any kind whatsoever against Bank or any of Bank's present or former
employees,  officers,  directors,  attorneys,  or  agents  of  any kind in their
capacity  as  such  (collectively, the "Released Parties") and further, that the
Released  Parties  have  performed  all  of the respective obligations under the
Credit  Agreement and other Loan Documents and have complied with all provisions
therein  set  forth.  Borrower  acknowledges  that  as  of October 11, 2002, the
outstanding principal balance of the Revolving Loans is $0.00, and the aggregate
stated  amount of all Letters of Credit outstanding and available for drawing is
$1,150,000.

          7.     SUBSIDIARIES AND OWNERSHIP OF STOCK.

          Borrower represents and warrants to Bank that set forth m Exhibit 7 is
a  complete  and  accurate list of the Subsidiaries of the Borrower, showing the
jurisdiction  of  incorporation  of  each  and  showing  the  percentage  of the
Borrower's  ownership  of  the  outstanding stock of each Subsidiary. All of the
outstanding  capital  stock  of each such Subsidiary has been validly issued, is
fully paid and nonassessable, and is owned by the Borrower free and clear of all
Liens.

          8.     COURSE OF DEALING.

          No  course  of  dealing  heretofore  or hereafter between Borrower and
Bank,  or  any  failure or delay on the part of Bank in exercising any rights or
remedies under the Credit Agreement or existing by law shall operate as a waiver
of  any right or remedy of Bank with respect to said indebtedness, and no single
or  partial  exercise  of  any  right  or  remedy  hereunder  shall operate as a


FOURTH AMENDMENT TO CREDIT AGREEMENT - 9

waiver  or  preclusion  to the exercise of any other rights or remedies Bank may
have  in  regard  to  said  indebtedness.

          9.     GOVERNING LAW.

          This  Amendment is made in the State of Idaho, which state the parties
agree  has  a  substantial  relationship  to  the  parties and to the underlying
transaction  embodied  hereby.  Accordingly, in all respects, this Amendment and
the Loan Documents and the obligations arising hereunder and thereunder shall be
governed  by,  and  construed in accordance with, the laws of the State of Idaho
applicable  to contracts made and performed in such state and any applicable law
of  the  United  States  of  America.  Each  party  hereby  unconditionally  and
irrevocably  waives, to the fullest extent permitted by law, any claim to assert
that  the  law  of  any  jurisdiction other than the State of Idaho governs this
Amendment  and  the  Loan  Documents.

          10.     COSTS AND EXPENSES.

          Borrower  shall  pay  on  demand by Bank all Bank Expenses incurred by
Bank in connection with the preparation, execution, delivery, filing, recording,
and  administration  of  this  Amendment  or  any  of the documents contemplated
hereby,  including,  without  limitation,  the reasonable fees and out of pocket
expenses  of  counsel  for Bank with respect to this Amendment and the documents
and  transactions  contemplated  hereby.

          11.     ENTIRE AGREEMENT.

          The  Credit  Agreement  as amended by this Amendment together with the
other  Loan  Documents  supersedes  all  prior negotiations, understandings, and
agreements  between  the  parties,  whether  oral  or  written,  and  all  such
negotiations,  understandings,  and agreements are evidenced by the terms of the
Loan  Documents.  The  Credit Agreement may not be further altered or amended in
any  manner  except  by  a  writing  signed  by  Bank  and  Borrower.

          12.     EFFECTS OF THIS AMENDMENT.

          This  Amendment  shall  be  binding  and  deemed  effective when it is
executed  by  Borrower,  accepted  and  executed  by  Bank,  and  all conditions
precedent  set  forth in Section 3 have been fulfilled. All terms, covenants and
conditions  of  the  Credit  Agreement  that have not been modified, amended, or
otherwise  changed by this Amendment are reaffirmed and remain in full force and
effect.

          13.     COUNTERPARTS.

          This  Amendment maybe executed in counterparts and may be delivered by
facsimile  transmission. Each such counterpart shall constitute an original, but
all  such  counterparts  shall  constitute  but  one  Amendment.


FOURTH AMENDMENT TO CREDIT AGREEMENT - 10

          IN WITNESS WHEREOF, Borrower has executed this Amendment as of the
Date first written above.

                              BORROWER:

                              AMERICAN ECOLOGY CORPORATION

                              By
                                ------------------------------
                                James R. Baumgardner
                                Sr. Vice President and CFO

                               GUARANTOR'S CONSENT

          Each  Guarantor  consents  to,  acknowledges, and accepts the forgoing
Amendment.  Each Guarantor affirms and ratifies its Continuing and Unconditional
Guaranty  made  by  Guarantor  for  the  benefit  of  Bank (the "Guaranty"), and
confirms that the Guaranty remains in full force and effect and binding upon the
Guarantor  without  any  setoffs,  defenses,  or  counterclaims  of  any  kind
whatsoever. Each Guarantor also acknowledges and reaffirms all existing security
agreements, financing statements, and any other documents the Guarantor executed
in  connection  with  the  Guaranty  or  the  Credit  Agreement.

          Dated as of October 15, 2002.

                              GUARANTORS:

                              AMERICAN ECOLOGY SERVICES CORPORATION


                              By
                                ------------------------------
                                James R Baumgardner
                                Vice President and Treasurer


                              AMERICAN ECOLOGY MANAGEMENT CORPORATION


                              By
                                ------------------------------
                                James R Baumgardner
                                Vice President and Treasurer


FOURTH AMENDMENT TO CREDIT AGREEMENT - 11

                              TEXAS ECOLOGISTS, INC


                              By
                                ------------------------------
                                James R. Baumgardner
                                Vice President and Treasurer


                              AMERICAN ECOLOGY RECYCLE CENTER, INC.


                              By
                                ------------------------------
                                James R, Baumgardner
                                Vice President and Treasurer


                              AMERICAN ECOLOGY ENVIRONMENTAL SERVICES
                              CORPORATION


                              By
                                ------------------------------
                                James R, Baumgardner
                                Vice President and Treasurer


                              US ECOLOGY, INC.


                              By
                                ------------------------------
                                James R, Baumgardner
                                Vice President and Treasurer


                              US ECOLOGY IDAHO, INC.


                              By
                                ------------------------------
                                James R, Baumgardner
                                Vice President and Treasurer


FOURTH AMENDMENT TO CREDIT AGREEMENT - 12

                                BANK'S ACCEPTANCE

          Accepted  and  effective  as  of the 15th day of October, 2002, in the
State of Idaho.

                              WELLS FARGO BANK, NATIONAL ASSOCIATION

                              By
                                ------------------------------
                                Brian W. Cook, Vice President




FOURTH AMENDMENT TO CREDIT AGREEMENT - 13

                                   EXHIBIT 3A

                             Form of Revolving Note

                                  See attached




EXHIBIT 3A - 1

                                 REVOLVING NOTE

Borrower:            AMERICAN ECOLOGY CORPORATION                October 15,2002
                                                                    Boise, Idaho

Address:             805 W. Idaho, Suite 200
                     Boise, Idaho 83702

Principal Amount:    Six Million Dollars ($6,000,000)

          FOR  VALUE  RECEIVED,  AMERICAN  ECOLOGY  CORPORATION,  a  Delaware
corporation  ("Borrower"),  promises  to  pay  to the order of WELLS FARGO BANK,
NATIONAL  ASSOCIATION  ("Bank")  the  total principal amount outstanding on this
note  (the  "Note")  together  with  interest thereon as stated below, in lawful
money  of  the  United  States  of  America.

          This  Note  is executed pursuant to and is the Revolving Note referred
to in that certain Credit Agreement, dated August 17, 2000, between Borrower and
Bank  (as  amended,  modified,  or  supplemented  from time to time, the "Credit
Agreement").  Capitalized terms used but not defined in this Note shall have the
same  definitions  as  are  ascribed to such terms in the Credit Agreement. This
Note  is  governed  by  the  provisions  of  the  Credit  Agreement.

          This  Note  is  a  revolving promissory note and evidences a revolving
line  of  credit  not to exceed the maximum principal amount stated above at any
one  time. The amount outstanding on this Note at any specific time shall be the
total  amount  advanced  by Bank less the amount of principal payments made from
time  to  time,  plus  any  interest  due  and  payable.

          Borrower  agrees that any and all advances made hereunder shall be for
Borrower's  benefit,  whether  or  not said advances are deposited to Borrower's
account.  Advances  may be made at the request of those persons so identified in
the  Credit Agreement and such persons are hereby authorized to request advances
and to direct the disposition of any such advances in the manner provided in the
Credit  Agreement  until  written  notice  of  revocation  of  this authority is
received  by  Bank  from  Borrower.

          The  outstanding  unpaid balance of this Note shall bear interest at a
fluctuating per annum rate as set forth in the Credit Agreement. This Note shall
be  repaid  in  the  manner  set  forth  in  the  Credit  Agreement.

          This  Note  is  secured,  in  part,  by  a Security Agreement covering
accounts  and  other collateral as provided therein and in the Credit Agreement.

          This Note is made in the state of Idaho, which state the parties agree
has  a substantial relationship to the parties and to the underlying transaction
embodied  hereby.  Accordingly,  in  all respects, this Note and the obligations
arising  hereunder  shall  be governed by, and construed in accordance with, the
laws  of  the  state of Idaho applicable to contracts made and performed in such
state  and any applicable law of the United States of America. Each party hereby
unconditionally  and irrevocably waives, to the fullest extent permitted by law,
any  claim  to  assert  that  the  law  of  any


EXHIBIT 3A - 2

jurisdiction  other  than  the  state  of Idaho governs this Note. All disputes,
controversies,  or  claims  arising  out  of,  or  in connection with, this note
shall be litigated  in  any  court of competent jurisdiction within the state of
Idaho. Each party hereby accepts jurisdiction of such state and agrees to accept
service of process as if it were personally served within such state. Each party
irrevocably  waives,  to the fullest extent permitted by law, any objection that
the  party  may  now or hereafter have to the jurisdiction of the courts of such
state  and any claim that any such litigation brought in any such court has been
brought  in  an  inconvenient  forum.

          Except  as  expressly  provided  in  the Credit Agreement, the makers,
sureties,  guarantors  and  endorsers  of  this note jointly and severally waive
presentment  for payment, protest, notice of protest and notice of nonpayment of
this  Note,  and consent that this Note or any payment due under this Note maybe
extended or renewed without demand or notice, and further consent to the release
of  any  collateral  or  part  thereof,  with  or  without  substitution.

                              AMERICAN ECOLOGY CORPORATION

                              By
                                ------------------------------
                                James R. Baumgardner
                                Sr. Vice President and CFO


EXHIBIT 3A - 3



                                       EXHIBIT 7

                     AMERICAN ECOLOGY CORPORATION AND SUBSIDIARIES

                                    (as of 10/15/02)

                                                       PERCENTAGE
                                                        OF STOCK
                                            PARENT      OWNED BY
COMPANY NAME/ADDRESSES                       CORP        PARENT        INCORP.
- ----------------------------------------  -----------  -----------  -------------
                                                           
American Ecology Corporation (AEC)        N/A          N/A          Delaware
300 E. Mallard, Suite 300                                           3/23/87
Boise ID 83706
                        BIN 95-3889638
- ----------------------------------------  -----------  -----------  -------------
American Ecology Environmental Services   AEC                 100%  Texas
Corporation (AEESC)                                                 6/12/80
13640 Highway 155 North
Tyler TX 75708                                                      f/k/a
P.O. Box 248                                                        Gibraltar
WinonaTX 75792                                                      Chemical
                        BIN 75-1747175                              Resources, Inc.
                                                                    (name change
                                                                    1/4/95)
- ----------------------------------------  -----------  -----------  -------------
American Ecology Management Corporation   AEC                 100%  Delaware
(AEMC)                                                              9/22/94
805 W. Idaho
Suite 200
Boise ID 83702
                        Inactive Pending
- ----------------------------------------  -----------  -----------  -------------
American Ecology Recycle Center, Inc.     AEC                 100%  Delaware
(AERC)                                                              3/31/94
109 Flint Road
Oak Ridge TN 37830                                                  d/b/a US Ecology
                        BIN 62-1568988                              Nuclear
                                                                    Equipment Service
                                                                    Center (4/8/96)
                                                                    d/b/a US Ecology
                                                                    Nuclear Materials
                                                                    Management
                                                                    Center (4/8/96)
- ----------------------------------------  -----------  -----------  -------------
American Ecology Services Corporation     AEC                 100%  Delaware
(AESC)                                                              2/24/93
13 IN. RicheyRoad
Pasadena TX 77506
                        BIN 76-0400703
- ----------------------------------------  -----------  -----------  -------------
Texas Ecologists, Inc. (TECO)             USE                 100%  Texas
P.O. Box 307                                                        11/22/71
RobstownTX 78380
                        BIN 94-2 1643 12
- ----------------------------------------  -----------  -----------  -------------


EXHIBIT 7 - 1

                                                       PERCENTAGE
                                                        OF STOCK
                                            PARENT      OWNED BY
COMPANY NAME/ADDRESSES                       CORP        PARENT        INCORP.
- ----------------------------------------  -----------  -----------  -------------
US Ecology, Inc. (USE)                    AEC                 100%  California
300 E. Mallard Drive, Suite 300                                     9/22/52
Boise ID 83706
                                                                    f/k/a
                                                                    Nuclear
                                                                    Engineering
                        BIN 94-1406536                              Company, Inc.
                                                                    (name change
                                                                    12/11/80)
- ----------------------------------------  -----------  -----------  -------------
US Ecology Idaho, Inc. (USEI)             AEC                 100%  Delaware
P.O. Box 400                                                        12/26/01
Lemley Road
Grand View, ID 83624                                                f/k/a
                        BIN 82-0365987                              Envirosafe
                                                                    Services of Idaho,
                                                                    Inc.
                                                                    (name change
                                                                    5/1/01)
- ----------------------------------------  -----------  -----------  -------------



EXHIBIT 7 - 2