CHANGE OF CONTROL AGREEMENT

This CHANGE OF CONTROL AGREEMENT (this “ Agreement ”) is entered into this  5th  day of  February, 2007 (the “ Effective Date ”) between John M. Cooper (“ Employee ”) and AMERICAN ECOLOGY CORPORATION, a Delaware corporation (the “ Company ”).  This Agreement is intended to provide Employee with the compensation and benefits described herein upon the occurrence of specific events following a change of control of the ownership of the Company (defined as “ Change of Control ”).  Certain capitalized terms used in this Agreement are defined in Article 6 .

WHEREAS , it is expected that the Company from time to time may consider or may be presented with the need to consider the possibility of an acquisition by another company or other change in control of the ownership of the Company.  The Board of Directors of the Company (the “ Board ”) recognizes that such considerations can be a distraction to Employee and can cause the Employee to consider alternative employment opportunities or be influenced by the impact of such possible change in control on Employee’s personal circumstances.  The Board has determined that it is in the best interests of the Company and its stockholders to assure that the Company will have the continued dedication and objectivity of Employee, notwithstanding the possibility or occurrence of a Change of Control of the Company; and

WHEREAS , the Board believes that it is in the best interests of the Company and its shareholders to provide Employee with an incentive to continue his or her employment and to motivate Employee to maximize the value of the Company upon a Change of Control for the benefit of its stockholders.

NOW, THEREFORE , the Company and Employee hereby agree as follows:

Article 1.                        EMPLOYMENT BY THE COMPANY.

1.1            Effect of Agreement .   This Agreement shall commence on the Effective Date and shall remain in full force and effect so long as Employee is employed by Company.

1.2            “ At-Will” Employment .   The Company and Employee each agree and acknowledge that Employee is employed by the Company as an “at-will” employee and that either Employee or the Company has the right at any time to terminate Employee’s employment with the Company, with or without cause or advance notice, for any reason or for no reason.  The Company and Employee wish to set forth the compensation and benefits which Employee shall be entitled to receive in the event that Employee’s employment with the Company terminates under the circumstances described in Article 3 below.

1.3            Consideration .   The duties and obligations of the Company to Employee under this Agreement shall be in consideration for Employee’s past services to the Company, Employee’s continued employment with the Company and Employee’s execution of the general waiver and release described in Section 5.2 .  The Company and Employee agree that Employee’s execution of the general waiver and release described in Section 5.2 is a precondition to Employee’s entitlement to the receipt of benefits under this Agreement and that these benefits shall not be earned unless all such conditions have been satisfied through the scheduled date of payment.  The Company hereby declares that it has relied upon Employee’s commitments under this Agreement to comply with the requirements of Article 5 , and would not have been induced to enter into this Agreement or to execute this Agreement in the absence of such commitments.

Article 2.                      PAYMENT UPON CHANGE OF CONTROL.

Upon a Change of Control of the Company, Employee shall receive an amount equal to 100% of Employee’s then current Base Salary.  Such payment shall be paid in a single lump-sum payment, within forty-five (45) days following the date of the Change of Control.

Article 3.                      TERMINATION EVENTS.

3.1            Involuntary Termination Upon or Following Change of Control .   In the event Employee’s employment with the Company or one of its subsidiaries is involuntarily terminated at any time by the Company without Cause either (i) at the time of or within twelve (12) months following the occurrence of a Change of Control, or (ii) at any time prior to a Change of Control, if such termination is at the request of an “Acquiror,” then such termination of employment will be a Termination Event and the Company shall pay Employee the compensation and benefits described in Article 3 .  In addition, the Company shall pay Employee the Accrued Obligations.  An “ Acquiror ” is either a person or a member of a group of related persons representing such group that in either case obtains effective control of the Company in a transaction or a group of related transactions constituting the Change of Control.

3.2            Involuntary Termination for Cause .   In the event Employee’s employment with the Company or one of its subsidiaries is involuntarily terminated by the Company for Cause at any time, then such termination of employment will not be a Termination Event, Employee will not   be entitled to receive any payments or benefits under the provisions of this Agreement, and the Company will cease paying compensation or providing benefits to Employee as of Employee’s termination date.  In addition, in the event of termination for Cause, Employee shall immediately and automatically forfeit all vested and unvested Stock Options and all unvested shares of Restricted Stock, if any.

3.3            Voluntary Termination .   Employee may voluntarily terminate his or her employment with the Company and/or its subsidiaries at any time.  In the event (i) Employee voluntarily terminates his or her employment for any reason, or (ii) Employee’s employment terminates on account of either death or physical or mental disability, then such termination of employment will not be a Termination Event, Employee will not be entitled to receive any payments or benefits under the provisions of this Agreement, and the Company will cease paying compensation or providing benefits to Employee as of the Employee’s termination date; provided, however , that pursuant to Company policy, the Employee’s health benefits shall extend to the last day of the calendar month in which employment termination occurs; and provided, further , that the Company shall pay Employee (or his or her estate or personal representative, in the event of Employee’s death) the Accrued Obligations.

Article 4.                      COMPENSATION AND BENEFITS PAYABLE.

4.1            Right to Benefits .   If a Termination Event occurs, Employee shall be entitled to receive the benefits described in this Agreement so long as Employee complies with the conditions set forth in Article 5 . If a Termination Event does not occur, Employee shall not be entitled to receive any benefits described in this Agreement, except as otherwise specifically set forth herein.

4.2            MIP Bonus; Accrued Obligations .   Upon the occurrence of a Termination Event, Employee shall receive his or her pro rata portion (based on the number of calendar months or portion thereof elapsed during the year as of the date of the Termination Event) of that year’s target/base bonus amount under the Company’s Management Incentive Plan, accrued as of the date of the Termination Event, if any, less any applicable withholding of federal, state or local taxes.  Such MIP bonus payment, if any, shall be paid in a single, lump-sum payment, within forty-five (45) days following the date of the Termination Event, subject to the limitations set forth in Section 4.6 , if applicable.  Employee shall also be entitled to receive payment of the Accrued Obligations.

4.3            Health Insurance Coverage .   Following the occurrence of a Termination Event, Employee shall be entitled, at the Company’s expense, to continue to receive the health insurance coverage to which Employee and his or her dependents were entitled as of the date of the Termination Event and for a period of twelve (12) months thereafter.

4.4            Equity Award Acceleration .

(a)           Employee’s stock options, if any, which are outstanding as of the date of the Termination Event (the “ Stock Options ”) shall become fully (100%) vested upon the occurrence of the Termination Event.  The maximum period of time during which the Stock Options shall remain exercisable, and all other terms and conditions of the Stock Options, shall be as specified in the relevant Stock Option agreements and relevant stock plans under which the Stock Options were granted.

(b)           Employee’s restricted stock awards, if any, that are outstanding as of the date of the Termination Event (“ Restricted Stock ”) shall become fully vested and free from any contractual rights of the Company to repurchase or otherwise reacquire the Restricted Stock as a result of Employee’s termination of employment.  Certificates representing all shares of Restricted Stock which have not yet been delivered to Employee or his designee (whether because the shares are uncertificated or subject to joint escrow instructions or otherwise) shall be promptly delivered to Employee or his or her designee upon the occurrence of a Termination Event.

4.5            Mitigation.   Except as otherwise specifically provided herein, Employee shall not be required to mitigate damages or the amount of any payment provided under this Agreement by seeking other employment or otherwise, nor shall the amount of any payment provided for under this Agreement be reduced by any compensation earned by Employee as a result of employment by another employer or by retirement benefits after the date of the Termination Event, or otherwise.

4.6   Compliance with Section 409A .   In the event that (i) one or more payments of compensation or benefits received or to be received by Employee pursuant to this Agreement (“ Agreement Payment ”) would constitute deferred compensation subject to Section 409A of the Internal Revenue Code of 1986, as amended (the “ Code ”) and (ii) Employee is deemed at the time of such termination of employment to be a “specified employee” under Section 409A(a)(2)(B)(i) of the Code, then such Agreement Payment shall not be made or commence until the earlier of (i) the expiration of the six (6)-month period measured from the date of Employee’s “separation from service” (as such term is at the time defined in Treasury Regulations under Section 409A of the Code) with the Company or (ii) such earlier time permitted under Section 409A of the Code and the regulations or other authority promulgated thereunder; provided, however , that such deferral shall only be effected to the extent required to avoid adverse tax treatment to Employee under Section 409A of the Code, including (without limitation) the additional twenty percent (20%) tax for which Employee would otherwise be liable under Section 409A(a)(1)(B) of the Code in the absence of such deferral.  During any period in which an Agreement Payment to Employee is deferred pursuant to the foregoing, Employee shall be entitled to interest on the deferred Agreement Payment at a per annum rate equal to the highest rate of interest applicable to six (6)-month non-callable certificates of deposit with daily compounding offered by the following institutions: Citibank N.A., Wells Fargo Bank, N.A. or Bank of America, on the date of such separation from service.  Upon the expiration of the applicable deferral period, any Agreement Payment which would have otherwise been made during that period (whether in a single sum or in installments) in the absence of this paragraph shall be paid to Employee or his or her beneficiary in one lump sum, including all accrued interest.

Article 5.                      LIMITATIONS AND CONDITIONS ON BENEFITS.

5.1            Reduction in Payments and Benefits; Withholding Taxes .   The benefits provided under this Agreement are in lieu of any benefit provided under any other severance plan, program or arrangement of the Company in effect at the time of a Termination Event.  The Company shall withhold appropriate federal, state or local income, employment and other applicable taxes from any payments hereunder.

5.2            Employee Release Prior to Receipt of Benefits . Upon the occurrence of a Termination Event, and prior to the receipt of any benefits hereunder, Employee shall, as of the date of a Termination Event, execute an employee release in the form attached hereto as Exhibit A .  Such employee release shall specifically relate to all of Employee’s rights and claims in existence at the time of such execution relating to Employee’s employment with the Company, but shall not include (i) Employee’s rights under this Agreement; (ii) Employee’s rights under any employee benefit plan sponsored by the Company; or (iii) Employee’s rights to indemnification under the Company’s charter, bylaws or other governing instruments or under any agreement addressing such subject matter between Employee and the Company.  It is understood that Employee has twenty-one (21) days to consider whether to execute such employee release and Employee may revoke such employee release within seven (7) business days after execution of such employee release. In the event Employee does not execute such employee release within the twenty-one (21) day period, or if Employee revokes such employee release within the seven (7) business day period, no benefits shall be payable under this Agreement and this Agreement shall be null and void.  Nothing in this Agreement shall limit the scope or time of applicability of such employee release once it is executed and not timely revoked.

5.3            Amendment or Termination of This Agreement . This Agreement may be changed or terminated only upon the mutual written consent of the Company and Employee; provided, however , that only prior to the period commencing three (3) months before the occurrence of a Change of Control, the Company may unilaterally terminate this Agreement following eighteen (18) months’ prior written notice to Employee. The written consent of the Company to a change or termination of this Agreement must be signed by an authorized officer of the Company, after such change or termination has been approved by the Company’s Board of Directors or the Compensation Committee of the Company’s Board of Directors.

5.3            Non-Alienation of Benefits .   No benefit hereunder shall be subject to anticipation, alienation, sale, transfer, assignment, pledge, encumbrance or charge, and any attempt to do so shall be void.

Article 6.                        OTHER RIGHTS AND BENEFITS NOT AFFECTED.

6.1            Nonexclusivity . Nothing in the Agreement shall prevent or limit Emplo