ZIP 94123
Water quality in San Francisco, CA (94123)
Drinking water in ZIP 94123 (San Francisco, City And County Of San Francisco County) comes from 1 public water system on EPA's records. The list below is ranked by population served: the largest regional authority for your area appears first, smaller subdivisions and private systems below.
Public water systems serving ZIP 94123
Ranked by population served. Tier badges show how EPA records each utility's service area: "Serves your city" means EPA's geographic-areas table specifically lists San Francisco; "Serves your county" means the utility serves City And County Of San Francisco County (regional authorities are usually filed this way); "Billing address at this ZIP" means the utility files paperwork from this ZIP but EPA does not confirm it serves you.
- Billing address at this ZIP
More for CA
How we matched ZIP 94123: we translate the ZIP to a city and county via the Geonames postal database, then match against service-area cities and counties EPA has on file for each public water system. EPA does not publish authoritative service-area boundary maps for most systems, so there is still some guesswork; large regional authorities (e.g., county-wide water and sewer authorities) are usually filed at the county level even when they serve specific cities. Your water bill names the authoritative utility. Methodology.