Marrero, LA tap water
Supplied mostly by Jefferson Parish Water Department, 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 about 0.44 ppm of ammonia here. Some utilities switch to plain chlorine for a few weeks a year.
Safety for fish and shrimp
Ammonia (with conditioner)
Estimate0.05–0.54 ppm (Low)
Typical 0.44 ppm
This is what a conditioner frees when it breaks the chloramine apart. A cycled filter clears it within a day.
Estimated from the chloramine level Jefferson Parish Water Department reports (2024).
Nitrate (NO₃)
0.1–0.6 ppm (Low)
Typical 0.6 ppm
Low, so water changes lower your tank's nitrate well.
From Jefferson Parish Water Department's 2024 water quality report; W Jefferson WW District 2, which supplies Westwego Waterworks.
Copper at home taps (first draw)
Up to 1.55 ppm (Worth knowing)
The 90th percentile of first-draw samples from homes: water that sat in household pipes for at least six hours.
Shrimp and snails are sensitive to copper. Water that sits in household pipes picks up the most; it drops once the tap has run for a minute.
Published by your utility: Jefferson Parish Water Department's 2024 water quality report.
Chlorine or chloramine at the tap
0.2–2.2 ppm
Typical 1.8 ppm
At tap levels, chlorine and chloramine are toxic to fish, shrimp and the bacteria in a filter. Water conditioners are made for this range.
Published by your utility: Jefferson Parish Water Department's 2024 water quality report.
Water chemistry
General hardness
Not published yet
We haven't found this number yet. A drop test kit gives you your exact reading.
Carbonate hardness (alkalinity)
75–82 ppm
Typical 75 ppm
Moderate buffering. pH should stay fairly steady.
From EPA monitoring data (2012–2016).
pH
6.9–7
Typical 7
Most community fish do well here. Stable water matters more than the exact number.
From EPA monitoring data (2012–2019).
- Jefferson Parish Water Department and Westwego Waterworks add phosphate to protect pipes. It can feed algae in tanks without much plant growth.
Who supplies Marrero, LA
- 2024 water quality report
Jefferson Parish Water Department
Serves 82% of residents · Lake or river water · Chloramine
Westwego Waterworks
Serves 17% of residents · Buys water from W Jefferson WW District 2 · 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.
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.