Common questions
Short answers about ZIP matching, confidence, filters, and help requests.
Is this a test of my faucet?
No. Reports summarize curated detections from California SDWIS monitoring extracts for a matched public water system. Home plumbing (especially lead) can differ.
How do you match my ZIP to a utility?
We prefer official service-area boundaries (SABL) using the ZIP centroid. If needed we fall back to utility HQ ZIP or a county-constrained city estimate. Overlaps show a chooser ā confirm the name on your bill.
What do high / multi / medium / low confidence mean?
High = unique SABL hit. Multi = overlapping service areas. Medium = HQ ZIP fallback. Low = city-level estimate. Details on the methodology page.
Why is my ZIP missing?
We focus on community systems with curated detections in the current extract window. Private wells and some small/wholesale systems may not appear. Try a neighboring ZIP or a region guide.
Do you sell plumber plans here?
No. TapCheck CA is the consumer report. Optional āAsk a local installerā may share your request with a local partner. We do not show plumber plan pricing on this site.
Can I open TapCheck on my phone from a public link?
Not until a public domain is pointed at a deployed host with HTTPS. Local demo ports on the build machine are not a phone URL. See DEPLOY-READINESS.md in the project for the checklist.
Where can I learn contaminant terms?
See the contaminant glossary and Filters 101.