Severn, MD tap water
Supplied mostly by Anne Arundel County, Department of Public Works, plus 3 other utilities. 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
Nitrite (NO₂)
Not detected (Low)
Not detected in testing, so any nitrite in your tank comes from the tank itself.
From EPA monitoring data (2018–2019).
Nitrate (NO₃)
Up to 11 ppm (Low)
Typical 2.6 ppm
Low, so water changes lower your tank's nitrate well.
From Anne Arundel County, Department of Public Works' 2025 water quality report; EPA monitoring data (2012–2025).
Copper at home taps (first draw)
0.01–0.38 ppm (Low)
The 90th percentile of first-draw samples from homes: water that sat in household pipes for at least six hours.
Low. Water that sits in household pipes overnight can carry more than this.
Published by your utility: Anne Arundel County, Department of Public Works' 2025 water quality report.
Chlorine or chloramine at the tap
0.7–1.7 ppm
Typical 1.3 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: Anne Arundel County, Department of Public Works' 2025 water quality report.
Water chemistry
General hardness
Area estimate13–188 ppm
Typical 114 ppm
Moderately soft to medium. Suits most community fish and plants.
Area estimate from nearby wells: USGS well samples in your county (2000–2022).
Carbonate hardness (alkalinity)
Area estimate3–178 ppm
Typical 121 ppm
Strong buffering. pH stays steady and hard to lower without RO water.
Area estimate from nearby wells: USGS well samples in your county (2000–2022).
pH
7.2–8.7
Typical 8.1
Alkaline. Many utilities raise pH to protect pipes. Stability matters more than the exact number.
Published by your utility: Anne Arundel County, Department of Public Works' 2025 water quality report.
Total dissolved solids
Area estimate42–336 ppm
Typical 168 ppm
A rough measure of everything dissolved in the water. RO water reads near 0, so TDS is a quick way to compare waters.
Area estimate from nearby wells: USGS well samples in your county (2000–2022).
Who supplies Severn, MD
- 2025 water quality report
Anne Arundel County, Department of Public Works
Serves 73% of residents · Groundwater (wells) · Chlorine
Crofton-Odenton
Serves 7% of residents · Groundwater (wells) · Chlorine
The Provinces
Serves 7% of residents · Groundwater (wells) · Chlorine
Maryland American Water--Severn System
Serves 6% of residents · Groundwater (wells) · 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.
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.