EXHIBIT
99.1





FIRST
AMENDMENT TO THE


REVOLVING
CREDIT AGREEMENT




This
First Amendment to the Revolving Credit Agreement (this “Amendment”) is made and
entered into effective as of April 8, 2009, by and between WELLS FARGO BANK, NATIONAL
ASSOCIATION (“Bank”), and AMERICAN ECOLOGY CORPORATION,
a Delaware corporation (“Borrower”).




R E C I T
A L S




A.           Borrower
and Bank entered into a Revolving Credit Agreement, dated as of June 30,
2008 (as amended, modified, or supplemented from time to time, the “Credit
Agreement”).




B.           Borrower
and Bank want to amend the Credit Agreement to modify the interest rate, modify
the computation of the Minimum Tangible Net Worth Covenant, and add US Ecology
Field Services, Inc. as a new guarantor (“New Guarantor”).




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 and Accounting Terms.




(i) The
definition of the term “Base Rate” in Section 1.1 of the Credit Agreement is
amended to use the Daily One Month LIBOR Rate, and the definition shall provide
in its entirety as follows:




“Base Rate” means the rate per
annum equal to the quotient of (i) the Daily One Month LIBOR Rate divided by
(ii) one (1) minus the LIBOR Reserve Percentage.  Each change in the
Base Rate shall become effective each Business Day that the Bank determines that
the Daily One Month LIBOR Rate has changed.




(ii)
Section 1.1 of the Credit Agreement is amended to add the definition “Daily One
Month LIBOR Rate,” and the definition shall provide in its entirety as
follows:




“Daily One Month LIBOR Rate”
means for any day the rate per annum for United States dollar deposits quoted by
Bank and the Inter-Bank Market Offered Rate in effect from time to time for
delivery of funds for one (1) month in amounts approximately equal to the
principal amount of the applicable Loan.  Borrower understands and
agrees that Bank may base its quotation of the Inter-Bank Market Offered Rate
upon such offers or other market indicators of the Inter-Bank Market as Bank in
its discretion deems appropriate including, but not limited to, the rate offered
for U.S. dollar deposits on the London Inter-Bank Market.









(iii) The
definition of the term “Guarantors” in Section 1.1 of the Credit Agreement is
amended to add New Guarantor, and the definition shall provide in its entirety
as follows:




“Guarantors” mean, jointly and
severally, each of Borrower’s Subsidiaries, including, without limitation, US
Ecology, Inc., a California corporation, US Ecology Texas, Inc., a Delaware
corporation, American Ecology Recycle Center, Inc., a Delaware corporation,
American Ecology Environmental Services Corporation, a Texas corporation, US
Ecology Idaho, Inc., a Delaware corporation, US Ecology Nevada, Inc., a Delaware
corporation, US Ecology Washington, Inc., a Delaware corporation, and US Ecology
Field Services, Inc., a Delaware corporation.




B.  Amendment
to Article 7 – Financial Covenants.




(i)
Section 7.2 of the Credit Agreement is amended to modify the computation of the
Minimum Tangible Net Worth Covenant, and the Section shall provide in its
entirety as follows:




7.2           Minimum Tangible Net
Worth.  Borrower shall maintain on a consolidated basis at the
end of each fiscal quarter a Tangible Net Worth of not less than the sum of (1)
Seventy-five Million and No/100 Dollars ($75,000,000.00), plus (2) 40% of
Borrower’s Adjusted Net Income.  “Tangible Net Worth” means the sum of
(i) Borrower’s total consolidated assets excluding all intangible assets (such
as goodwill, trademarks, patents, copyrights, and similar items), plus (ii) all
indebtedness of Borrower (including, without limitation, capital lease
obligations) that is subordinated to payment in full of the Obligations pursuant
to a written agreement in form and substance acceptable to Bank (“Subordinated
Debt”), less (iii) all of Borrower’s liabilities other than Subordinated
Debt.  “Adjusted Net Income” means Borrower’s consolidated net income
for all periods after March 31, 2008, without regard to any consolidated net
losses.




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.  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.




B.  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.




C.  Evidence
of all Corporate Action by New Guarantor.




Certified
copies of all corporate action taken by New Guarantor authorizing its execution
and delivery of the Guaranty and the performance of its agreements
thereunder.




D.  Certificate
of Existence of New Guarantor.




Certificates
of existence or good standing dated a reasonable date before the effective date
of this Amendment showing that New Guarantor is in good standing under the laws
of the state of its incorporation and all other states in which it is doing
business.









E.  Articles
of Incorporation and Bylaws of New Guarantor.




Copies of
the articles of incorporation and bylaws of New Guarantor certified by an
officer of New Guarantor to be true and correct.




F.  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.




G.  Additional
Documentation.




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




4.  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.




5.  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 March 5, 2009, there is no outstanding principal
balance of the Revolving Loans, and the aggregate stated amount of all Letters
of Credit outstanding and available for drawing is $4,027,105.




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




7.  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.









8.  COSTS AND
      EXPENSES.




Borrower
shall pay on demand by Bank all 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.




9.  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.




10.  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.




11.  COUNTERPARTS.




This
Amendment may be 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.




[Signature
Page Follows]









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






BORROWER:
              
              AMERICAN ECOLOGY
      CORPORATION
              
              
              By  /s/ Jeffrey R.
      Feeler
              Jeffrey
      R. Feeler
              Vice
      President and Chief Financial
Officer











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.




Dated as
of April 8, 2009.




GUARANTORS:
                
                US
      ECOLOGY TEXAS, INC.By:
              /s/ Jeffrey
      R. FeelerJeffrey
      R. FeelerVice
      President


AMERICAN ECOLOGY RECYCLE CENTER, INC.By:
                  /s/ Jeffrey
      R. FeelerJeffrey
      R. FeelerVice
      President
  AMERICAN ECOLOGY
      ENVIRONMENTAL SERVICES CORPORATIONBy:
                    /s/ Jeffrey
      R. FeelerJeffrey
      R. FeelerVice
      President
 US
      ECOLOGY, INC.By:
                      /s/ Jeffrey
      R. FeelerJeffrey
      R. FeelerVice
      President
 US
      ECOLOGY IDAHO, INC.By:
                        /s/ Jeffrey
      R. FeelerJeffrey
      R. FeelerVice
      President
 US
      ECOLOGY NEVADA, INC.By:
                            /s/ Jeffrey
      R. FeelerJeffrey
      R. FeelerVice
      President









US ECOLOGY
      WASHINGTON, INC.By:
                    /s/ Jeffrey
      R. FeelerJeffrey
      R. FeelerVice
      President
 US
      ECOLOGY FIELD SERVICES, INC.By:
                        /s/ Jeffrey
      R. FeelerJeffrey
      R. FeelerVice
      President


BANK’S
ACCEPTANCE


Accepted
and effective as of April 8, 2009, in the State of Idaho.


WELLS
      FARGO BANK, NATIONAL ASSOCIATIONBy:
                    /s/ Brian
      W. CookBrian
      W. Cook, Vice President