Westlake Village, CA tap water
Supplied mostly by Las Virgenes MWD, 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)
1.7–2.2 ppm (Low)
Typical 1.7 ppm
Low, so water changes lower your tank's nitrate well.
From California Water Board lab results (2023–2026).
Copper at home taps
0.09–0.1 ppm (Low)
Typical 0.09 ppm
Low. Water that sits in household pipes overnight can carry more than this.
From California Water Board lab results (2024).
Water chemistry
General hardness
140–161 ppm
Typical 140 ppm
Moderately soft to medium. Suits most community fish and plants.
From California Water Board lab results; Calleguas Municipal Water Dist, which supplies California Water Service Co - Westlake (2023–2026).
Carbonate hardness (alkalinity)
110–170 ppm
Typical 140 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
From California Water Board lab results; Calleguas Municipal Water Dist, which supplies California Water Service Co - Westlake (2023–2026).
pH
7.5–8.1
Typical 8.1
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From California Water Board lab results (2023–2026).
Total dissolved solids
340–420 ppm
Typical 340 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; Calleguas Municipal Water Dist, which supplies California Water Service Co - Westlake (2023–2026).
Who supplies Westlake Village, CA
Las Virgenes MWD
Serves 77% of residents · Lake or river water · Chloramine
California Water Service Co - Westlake
Serves 22% of residents · Buys water from Calleguas Municipal Water Dist · 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.