Pleasanton, CA tap water
Supplied mostly by Zone 7 Water Agency, plus 1 other utility. Here's what the water means for your fish.
Disinfectant
Chloramine
Your water is treated with chloramine. Unlike chlorine, it doesn't gas off when water sits out, and many pitcher and fridge filters aren't rated to remove it. Conditioners that list chloramine on the label break it apart, which frees a little ammonia. Some utilities switch to plain chlorine for a few weeks a year.
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 California Water Board lab results (2023–2026).
Nitrate (NO₃)
Up to 18 ppm (Low)
Typical 2.5 ppm
Low, so water changes lower your tank's nitrate well.
From California Water Board lab results; Zone 7 Water Agency, which supplies City of Pleasanton (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 (2023–2026).
Water chemistry
General hardness
79–368 ppm
Typical 146 ppm
Moderately hard. Great for livebearers, and most community fish adapt.
From California Water Board lab results; Zone 7 Water Agency, which supplies City of Pleasanton (2023–2026).
Carbonate hardness (alkalinity)
80–274 ppm
Typical 138 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results; Zone 7 Water Agency, which supplies City of Pleasanton (2023–2026).
pH
7.4–8.8
Typical 8
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From California Water Board lab results; Zone 7 Water Agency, which supplies City of Pleasanton (2023–2026).
Total dissolved solids
210–568 ppm
Typical 239 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; Zone 7 Water Agency, which supplies City of Pleasanton (2023–2026).
- Zone 7 Water Agency and City of Pleasanton soften their water at the plant, so it may be softer than the local groundwater.
Who supplies Pleasanton, CA
Zone 7 Water Agency
Serves 52% of residents · Lake or river water · Chloramine
City of Pleasanton
Serves 51% of residents · Buys water from Zone 7 Water Agency · 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.