Who owns the water service line in Hercules, CA

The threads are the line, and it is worth knowing because that is exactly where a leak tends to show and where two plumbers will disagree. EBMUD keeps the meter and the threads on your side of it; the pipe that screws on to those threads is yours. Two further things. Your two pipes divide in very different places across most of the East Bay: the water line stops being yours at the meter near the boundary, while the sewer lateral commonly stays yours all the way under the road to the main, so a quotation for "the line to the street" means different work depending on which pipe is meant - check your own city's sewer page rather than assuming. And a handful of East Bay addresses are not EBMUD's at all even inside these cities: Alameda Point in Alameda, Wildwood Acres Resort in Lafayette and the East Bay Regional Park District's Piedmont Stables in Oakland are separate water systems on the State's own register, so check whose name is on your water bill before relying on any of this. The same register also leaves some ground inside these cities with no published water service area over it - about a sixth of Richmond and a twentieth of Hercules - which is not a rival utility and not necessarily unserved, but is another reason to check the bill. And if you are offered a service line protection plan on the strength of EBMUD's own page, read who is selling it: EBMUD points customers at "optional coverage plans, offered by SLWA Insurance Services (SLWA), an independent company" and says plainly that it "does not endorse any coverage provider". That is insurance from a third party, not a utility scheme.