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To ensure proper operation and accessibility of all backflow prevention assemblies, the following requirements shall apply:

A. No part of the backflow prevention assembly shall be submerged in water or installed in a location subject to flooding. If a backflow prevention assembly is installed in a vault or basement, adequate drainage shall be provided. Reduced Pressure Principle Assemblies shall be installed above ground.

B. Assemblies must be installed at the point of use. Alternate locations must be requested in writing and approved by the City of Snohomish prior to installation.

C. The assembly must be protected from freezing and other severe weather conditions.

D. All backflow prevention assemblies to be installed shall be of a type and model pre-approved by the Washington State Department of Health and the City of Snohomish.

E. The assembly shall be readily accessible with adequate room for maintenance and testing. All devices shall have a minimum of twelve inches clearance on all sides of the device.

F. If written permission is granted to install the backflow assembly inside a building, the assembly shall be readily accessible during regular working hours of 8:00 a.m. to 4:30 p.m., Monday through Friday.

G. If an assembly is approved for installation inside of the premises, and it is installed five feet above the floor, it must be equipped with rigid and permanently installed scaffolding or platforms acceptable to the City of Snohomish. The installation must also meet the requirements set out by the U.S. Occupational Safety and Health Administration and the State of Washington Occupational Safety and Health Codes.

H. Reduced Pressure Principle Assemblies shall be installed above ground level only if a relief valve discharge can be drained to daylight through a “boresight” type drain. The drain shall be of adequate capacity to carry the full rated flow of the device and shall be screened on both ends.

I. An approved air gap shall be at least twice the inside diameter of the incoming supply line as measured vertically above the top rim of the drain and in no case less than one inch.

J. Where a backflow device is deemed necessary, the model of the assembly and installation plans shall be submitted to the City of Snohomish for approval prior to installation.

K. Upon backflow device installation, the City of Snohomish shall be notified and all devices shall be inspected and tested. All backflow devices must be registered with the City of Snohomish by means of the initial test report.

L. Prior to installation, any variances from these installation requirements shall be requested in writing by the owner and approved by the City of Snohomish.

M. The City shall be notified within twenty-four (24) hours of the installation of a backflow assembly, and an inspection scheduled with the Cross-Connection Control Specialist and the local administrative authority to ensure compliance. All backflow assemblies shall be tested upon installation and annually thereafter, and following any retrofit, by a Certified Backflow Assembly Tester, and a copy of all test reports submitted to the purveyor for approval within five (5) working days of the test.