San Gabriel, CA tap water
Supplied mostly by San Gabriel County WD, plus 1 other utility. Here's what the water means for your fish.
Disinfectant
Chlorine or chloramine
Utilities here use chlorine or chloramine, depending on which one serves your address. Chlorine slowly gases off from standing water; chloramine doesn't.
Safety for fish and shrimp
Nitrite (NO₂)
Not detected (Low)
Not detected in testing, so any nitrite in your tank comes from the tank itself.
From EPA monitoring data (2014–2019).
Nitrate (NO₃)
6.2–15 ppm (Low)
Typical 6.2 ppm
Water changes can't take your tank's nitrate below this level.
From California Water Board lab results (2023–2026).
Copper at home taps
0.06–0.07 ppm (Low)
Typical 0.07 ppm
Low. Water that sits in household pipes overnight can carry more than this.
From California Water Board lab results (2023–2025).
Water chemistry
General hardness
17–291 ppm
Typical 95 ppm
Moderately soft to medium. Suits most community fish and plants.
From California Water Board lab results, measured before treatment; Metropolitan Water Dist. of So. Cal. and Sierra Madre-City, Water Dept., which supplies Cal/Am Water Company - San Marino (2023–2026).
Carbonate hardness (alkalinity)
68–160 ppm
Typical 118 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results, measured before treatment; Metropolitan Water Dist. of So. Cal. and Sierra Madre-City, Water Dept., which supplies Cal/Am Water Company - San Marino (2023–2026).
pH
8–8.4
Typical 8.4
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From EPA monitoring data (2014–2019).
Total dissolved solids
160–666 ppm
Typical 250 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; Metropolitan Water Dist. of So. Cal. and Sierra Madre-City, Water Dept., which supplies Cal/Am Water Company - San Marino (2023–2026).
Who supplies San Gabriel, CA
San Gabriel County WD
Serves 63% of residents · Groundwater (wells) · Chlorine
Cal/Am Water Company - San Marino
Serves 21% of residents · Buys water from Metropolitan Water Dist. of So. Cal. · Chloramine
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.
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Compiled by Shoal & Stem from public records. Free to cite with a link.