Determine California requirements for a company hauling water to serve as or supply a domestic water system

Steps

1. Identify whether the served properties constitute a 'public water system' under the California Safe Drinking Water Act (based on number of service connections or people served)
2. If so, the water board's Division of Drinking Water requires submitting a domestic water supply permit application and technical report before operating, per the permit application form on waterboards.ca.gov
3. Note that many California cities/counties restrict issuing building permits for new residential development when a water hauler is the primary water source — check local planning requirements in parallel
4. Source water only from an already-approved public water system or state-approved source
5. Route the completed application and technical report to the appropriate Division of Drinking Water district engineer for review
6. Distinguish this drinking-water permit track from a water rights permit/registration (Division of Water Rights), which governs the right to divert water, not its distribution safety