Water supplies for automatic sprinkler systems shall comply with this section and the standards referenced in Section 903.3.1. The potable water supply shall be protected against backflow in accordance with Health and Safety Code 13114.7. For connections to public waterworks systems, the water supply test used for design of fire protection systems shall be adjusted to account for seasonal and daily pressure fluctuations based on information from the water supply authority and as approved by the fire code official.
Where the domestic service provides the water supply for the automatic sprinkler system, the supply shall be in accordance with this section.
A single combination water supply shall be allowed provided that the domestic demand is added to the sprinkler demand as required by NFPA 13R.