1. A reduced pressure principle backflow prevention assembly shall be installed on all new and existing fire protection systems, which are determined to have any one of the following:
A. Direct connections from public water mains with an auxiliary water supply on or available to the premises for pumper connection.
B. Interconnections with auxiliary supplies such as reservoirs, rivers, ponds, wells, mills, or other industrial water systems.
C. Use of antifreezes or other additives in the fire protection system.
D. Combined industrial and fire protection systems supplied from public water mains only, with or without gravity storage or pump suction tanks.
E. Any other facility, connection, or condition, which may cause contamination.
2. A double check valve assembly will be required for all other fire protection systems. The double check valve assembly shall be required on all new systems at the time of installation and on existing systems at the time that they are upgraded.
3. Submittal of proposed backflow prevention devices to Des Moines Water Works does not relieve the designer or the sprinkler contractor of the responsibility of submitting plans, including backflow prevention devices to the City of Windsor Heights for approval.