Dept. of Trans.       SUPPLEMENTAL   Serial No.  Contract No.                           
                                          07-284-14-32  08-334844                       
                PROGRESS PAYMENT VOUCHER  %complete:   %time:                           
Location:                                  82%          76%                             
08-RIV-215-R37.7/43.9                    Federal Project:                               
08-RIV-91-20.3/21.6                                     ACNH-215-1(219)                 
08-RIV-60-11.5/13.7                             I-215-1(219)                            
                             ACNH-X065(80)                                              
Progress payment No. 56            Payment period ending: 09-20-07                      
WASHINGTON GROUP INTERNATIONAL                                                          
INC OBAYASHI CORPORATION A                                                              
JOINT VENTURE                                                                           
P O BOX 600                                                                             
HIGHLAND CA 92346                                                                       
Escrow No.  02171                                                                       
                                    Total Estimate   This Estimate                      
1. Contract Itms Without Mobil.     138,561,852.95      399,959.72                      
2.a. Extra Work                      16,105,399.61      307,119.92                      
  b. Adjustment Comp.                32,746,230.26        1,585.03                      
3. Materials on Hand                  1,488,021.40            0.00                      
4. Earned Subject to Retention      188,901,504.22      708,664.67                      
5. Mobilization                      18,343,064.95            0.00                      
6. Total Work Completed  205,756,547.77                                                 
7. Deductions                          -407,252.40            0.00                      
8. a.Contract Retentions             -9,445,075.21      -35,433.23                      
   b. Unsatisfactory Prog.                                                              
   c. Reduction after 95% Comp.                                                         
9. Total pay to Contractor          197,392,241.56      673,231.44                      
10. Reduction Amt to Escrow                                                             
11. Payment to Escrow     9,445,070.00                                                  
12. Net Pymt. this Estimate                             673,231.44