Johnstonville, CA tap water
About 15% of Johnstonville is inside a utility's service area. Homes outside it likely use private wells, which no utility tests.
Disinfectant
Not confirmed
We couldn't confirm how utility water here is disinfected. US utilities use chlorine or chloramine, and chloramine doesn't gas off when water sits out. Private wells aren't treated by a utility, so there's no chlorine or chloramine unless a treatment system adds it.
Safety for fish and shrimp
Nitrate (NO₃)
Not detected (Low)
Not detected in testing, so water changes lower your tank's nitrate well.
From California Water Board lab results, measured before treatment (2023–2026).
Copper at home taps
Not detected (Low)
Not detected in testing. Water that sits in household pipes overnight can still pick some up.
From California Water Board lab results (2024).
Water chemistry
General hardness
95 ppm
Moderately soft to medium. Suits most community fish and plants.
From California Water Board lab results, measured before treatment (2025).
Carbonate hardness (alkalinity)
140 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results, measured before treatment (2025).
pH
7.8
Most community fish do well here. Stable water matters more than the exact number.
From California Water Board lab results, measured before treatment (2025).
Total dissolved solids
160 ppm
A rough measure of everything dissolved in the water. RO water reads near 0, so TDS is a quick way to compare waters.
From California Water Board lab results, measured before treatment (2025).
Who supplies Johnstonville, CA
Susan River Park Water Co.
Serves 13% of residents · Groundwater (wells) · Disinfectant not listed
Lassen Mobile Home Park
Serves 5% of residents · Groundwater (wells) · Disinfectant not listed
Our data comes from public records and is still incomplete. Many utilities don't publish every number, so we're adding more all the time. Your city's range is a starting point: testing your own tap is the only way to know exactly what's in it.
Tap water lookup covers US cities only for now. Want to know why it matters? Read our story on tap water.
Compiled by Shoal & Stem from public records. Free to cite with a link.