Exhibit 3.766

STATE OF DELAWARE

SECRETARY OF STATE

DIVISION OF CORPORATIONS

FILED 12:30 PM 02/23/2000

001090493 – 3181816

CERTIFICATE OF FORMATION

OF

RS/WM HOLDING COMPANY, LLC

1. The name of the limited liability company is RS/WM Holding Company, LLC

2. The address of its registered office in the State of Delaware is Corporation Trust Center. 1209 Orange Street, in the City of Wilmington, County of New Castle. The name of its registered agent at such address is The Corporation Trust Company.

     IN WITNESS WHEREOF, the undersigned has executed this Certificate of Formation of RS/WM Holding Company, LLC, this 23rd day of February, 2000.

/s/ David A. Barclay  

David A. Barclay, Authorized Person 

State of Delaware

Secretary of State

Division of Corporations

Delivered 05:06 PM 03/02/2004

FILED 04:48 PM 03/02/2004

SRV 040159672 – 3181816 FILE

CERTIFICATE OF AMENDMENT

OF

RS/WM HOLDING COMPANY, LLC

     1. The name of the limited liability company is RS/WM HOLDING COMPANY, LLC.

     2. The Certificate of Formation of the limited liability company is hereby amended as follows:

     The name of the limited liability company shall be Republic Services Group, LLC.

     IN WITNESS WHEREOF, the undersigned has executed this Certificate of Amendment of RS/WM Holding Company, LLC this 2^nd day of March, 2004.

RS/WM HOLDING COMPANY, LLC

By: it’s sole member

REPUBLIC SERVICES, INC.

/s/ David A. Barclay

David A. Barclay, Vice President &

Assistant Secretary