Maple Valley, WA tap water
Supplied mostly by Covington Water District, plus 1 other utility. Here's what the water means for your fish.
Disinfectant
Chlorine
Your water is treated with chlorine. It slowly gases off from standing water, and any water conditioner removes it.
Safety for fish and shrimp
Nitrate (NO₃)
Supplier's figureUp to 44 ppm (Low)
Typical 8.9 ppm
Water changes can't take your tank's nitrate below this level.
From the utility that supplies yours: Cedar River Water & Sewer District and City of Tacoma Water Division, which supplies Covington Water District, measured before treatment; Seattle Public Utilities and Covington Water District, which supplies Cedar River Water & Sewer District (2012–2025).
Water chemistry
General hardness
Supplier's figure25 ppm
Soft. Good for tetras, rasboras and most shrimp. Livebearers, snails and African cichlids prefer harder water.
From the utility that supplies yours: Seattle Public Utilities, which supplies Covington Water District; Seattle Public Utilities, which supplies Cedar River Water & Sewer District.
Carbonate hardness (alkalinity)
Supplier's figure23–28 ppm
Typical 26 ppm
Little buffering. pH can drop quickly between water changes, especially with CO₂ or an older tank.
From the utility that supplies yours: City of Tacoma Water Division, which supplies Covington Water District; Seattle Public Utilities, which supplies Cedar River Water & Sewer District (2012–2019).
pH
Supplier's figure7.5–8.5
Typical 8.3
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
From the utility that supplies yours: Seattle Public Utilities, which supplies Covington Water District; Seattle Public Utilities, which supplies Cedar River Water & Sewer District.
Total dissolved solids
Supplier's figure36 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 the utility that supplies yours: Seattle Public Utilities, which supplies Covington Water District; Seattle Public Utilities, which supplies Cedar River Water & Sewer District.
Who supplies Maple Valley, WA
Covington Water District
Serves 64% of residents · Buys water from Cedar River Water & Sewer District · Chlorine
Cedar River Water & Sewer District
Serves 24% of residents · Buys water from Seattle Public Utilities · Chlorine
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.