**EXHIBIT 10.18.1**

THIS SECOND AMENDMENT AGREEMENT (1997 L/C) (this “Agreement”) is dated as of May 1, 2007, by and between West Valley MRF, LLC, aCalifornia limited liability company (the “Borrower”) and Union Bank of California, N.A. (the “Bank”) and is being entered into in connection with the following: 

A. The Bank and the Borrower are party to a Reimbursement Agreement dated as of June 1, 1997 as amended by that certain Extension and AmendmentAgreement dated as of May 5, 2005 (as so amended, the “Reimbursement Agreement”), pursuant to which the Bank has issued its Irrevocable Letter of Credit No. 306S230625, dated June 25, 1997 (as heretofore amended, the“Letter of Credit”) in favor of BNY Western Trust Company, as Trustee. Capitalized terms used herein without definition shall have the respective meanings ascribed thereto in the Reimbursement Agreement. 

B. Under Section 1(g) of the Reimbursement Agreement, the Borrower is required to make monthly deposits into the Deposit Account so that theaggregate annual amount of such deposits is equal to the respective amounts shown on the bond amortization/reimbursement deposit schedule attached as Exhibit B to the Reimbursement Agreement. The Borrower has requested that the bondamortization/reimbursement deposit schedule be amended to reduce both the monthly deposit requirement and the amount required for the annual partial redemption of Bonds. The Bank has approved this request subject to the terms and conditionshereinafter set forth. 

NOW, THEREFORE, the Bank and the Borrower do hereby agree as follows: 

1. Effective as of the Effective Date (as defined below), the Bank and the Borrower agree that the bond amortization/reimbursement deposit scheduleattached as Exhibit B to the Reimbursement Agreement is hereby deleted and is replaced by a new Exhibit B in the form attached hereto. This Agreement and such written consent may be executed in counterparts and the Bank may accept execution ofcounterparts via facsimile transmission. 

2. The Borrower hereby represents and warrants to the Bank as follows: 

(a) No Default or Event of Default under the Reimbursement Agreement, the Deed of Trust or any Related Document has occurred and iscontinuing; 

(b) The execution, delivery and performance by the Borrower of this Agreement have been duly authorized by allnecessary company action and do not and will not require any registration with, consent or approval of, notice to or action by, any person (including any governmental agency) in order to be effective and enforceable. The Deed of Trust constitutesthe legal, valid and binding obligation of the Borrower, enforceable against it in accordance with its terms, without defense, counterclaim or offset; and 

(c) All representations and warranties of the Borrower under the Reimbursement Agreement and the Deed of Trust are true and correct fully as if made on the date hereof. 

3. When both of the following conditions precedent have been satisfied or waived by the Bank, this Agreement will be deemed effective as of May 1,2007 (“Effective Date”): 

(a) The Bank has received from the Borrower a counterpart of this Agreement duly executedby the Borrower together with a fully executed copy of a Guarantors’ Acknowledgment and Consent in form and substance satisfactory to the Bank; and 

(b) All representations and warranties of the Borrower contained herein and in the Reimbursement Agreement are true and correct as of the Effective Date and no Event of Default, and no event which with notice or lapseof time or both would become an Event of Default, shall have occurred and be continuing under the Reimbursement Agreement. 

4. This SecondAmendment Agreement may be executed in multiple counterparts which taken together shall constitute one and the same document. As modified hereby, the Reimbursement Agreement is hereby ratified, approved and confirmed and remains in full force andeffect. 

IN WITNESS WHEREOF, the Bank and the Borrower have executed this Second Amendment Agreement effective as of the date first setforth above. 

 

WEST VALLEY MRF, LLC,

a California limitedliability company
By: Kaiser Recycling, LLC, a Delaware limited liability company, member By: /s/ James F. Verhey  Name: James F. Verhey  Title: Vice PresidentBy: 
West Valley Recycling & Transfer, Inc.,

a California corporation, member
 By: /s/ Cole Burr  Name: Cole Burr  Title: President
 
UNION BANK OF CALIFORNIA, N.A.By: /s/ Myra Juetten Name: Myra Juetten Title: Vice President
 

-2- 

EXHIBIT B 

**REIMBURSEMENT DEPOSIT SCHEDULE**

 

**Twelve Months Ending in June**
  
**Annual DSR Deposit Amount**

2007
  630,000
2008
  630,000
2009
  630,000
 

-3-