Sonora Tap Water Quality Report
No test results on file for TUD - TUOLUMNE WATER SYSTEM, Sonora's water system. Results from other water systems on this page are listed under each system's name; they are not TUD - TUOLUMNE WATER SYSTEM's results and do not make a verdict for Sonora. Check TUD - TUOLUMNE WATER SYSTEM's latest Consumer Confidence Report for its current test results.
No single water system serves most of Sonora (4,855 residents, Census 2024 estimate). Its large systems are TUD - TUOLUMNE WATER SYSTEM (EPA counts 1,761 people served, about 36% of Sonora's population); TUD - SONORA/JAMESTOWN WATER SYSTEM (EPA counts 11,620 people served, more than Sonora's population); TUD - COLUMBIA WATER SYSTEM (EPA counts 4,917 people served, more than Sonora's population). EPA's counts may include people served outside Sonora, so each share is at most that. Check which one bills you: each system's figures are shown separately below.
- TUD - TUOLUMNE WATER SYSTEM: No contaminant results on file; health-based violations since 2020: 0
- TUD - SONORA/JAMESTOWN WATER SYSTEM: 78 contaminants tested, 1 above EPA MCLGs; health-based violations since 2020: 0
- TUD - COLUMBIA WATER SYSTEM: 74 contaminants tested, 0 above EPA MCLGs; health-based violations since 2020: 0
Other systems listed for Sonora with results above guidelines: TUD - SONORA/JAMESTOWN WATER SYSTEM (1 above guidelines), BLUEBELL VALLEY MWC (2 above guidelines), TUD-WARDS FERRY RANCHES (1 above guidelines)
Water systems
3 large systems
Residents (Census 2024)
4,855
Health-based violations since 2020
0
TUD - TUOLUMNE WATER SYSTEM. EPA SDWA violation data as of Q2 2026 (downloaded 2026-07-09).
Is Sonora Tap Water Safe to Drink?
Everything we hold on Sonora's water is below — a thin record, not a clean one. Testing your own water is the way to find out what your tap is actually delivering.
TUD - TUOLUMNE WATER SYSTEM, Sonora's water system, serves 1,761 people. 6 other systems are listed for Sonora. Each system's results are listed under its own name, never added to TUD - TUOLUMNE WATER SYSTEM's.
Boil water advisories are issued by water systems and state agencies, and they change from day to day. Boil water advisories in California
Sonora Water Service Areas
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General-Purpose Water Filters for Sonora
No test results are on file for TUD - TUOLUMNE WATER SYSTEM, Sonora's water system, so these are general-purpose NSF/ANSI 53 certified filters, not chosen for any contaminant.
Pentair Residential Filtration, LLC
Everpure Residential H-300-NXT
NSF Certified:
Capacity
3001 gal
Filter Life
10 mo
Flow Rate
0.5 gpm
Removes 5 contaminants:
Whirlpool Corporation
W11256135
NSF Certified:
Capacity
1001 gal
Filter Life
3 mo
Flow Rate
0.7 gpm
Removes 19 contaminants:
+14 more
Benzene, Carbofuran, Chlorine (Free), Chlorine (Total), Chlorine Dioxide, Chlorobenzene, Cryptosporidium, Ethylbenzene, Lead, Mercury, Metolachlor, Tetrachloroethylene, Toxaphene, Turbidity
Whirlpool Corporation
W11569861
NSF Certified:
Capacity
1001 gal
Filter Life
3 mo
Flow Rate
0.52 gpm
Removes 22 contaminants:
+17 more
Atrazine, Benzene, Carbofuran, Chlorine (Free), Chlorine (Total), Chlorine Dioxide, Chlorobenzene, Cryptosporidium, Ethylbenzene, Lead, Mercury, Metolachlor, Styrene, Tetrachloroethylene, Toxaphene, Trichloroethylene, Turbidity
Santevia
Bath Filter
NSF Certified:
Flow Rate
0.36 gpm
Highlights:
- Organic cotton design reduces plastic used in construction
- Affordable upfront & ongoing cost
- The only bath filter that removed 100% chlorine with “normal” faster faucet flow
Removes 1 contaminants:
No test results on file — test your own tap
We don't hold water-quality results for this system yet, so nobody can tell you what is in your water from published data. A certified lab test is the way to find out.
SimpleLab
Advanced Home Water Test
$269
Comprehensive water analysis testing over 200 contaminants including bacteria, heavy metals, and chemical compounds.
Tap Score
Advanced Microplastics Test
$829
Cutting-edge testing for microplastics particles in drinking water using advanced laboratory techniques.
Tap Score
Haloacetic Acids (HAA9) Test
$275
Tests for disinfection byproducts formed when chlorine reacts with organic matter in water treatment.
What Sonora's water readings can explain
We publish a city-level hardness figure for Sonora, resolved from its water systems where they report one and estimated from county sampling where they do not. Each page starts with the hot-tap and cold-tap check, then shows what your own water system reported.
On a private well near Sonora? Public-water results do not apply to private wells. See Tuolumne County well water testing and USGS risk data — modeled arsenic, nitrate, and the tests to run.
Water softener cost and installation in Sonora
Sonora's tap water has an estimated 0.2 grains per gallon (2.8 mg/L, county sampling in Tuolumne County) — soft on the USGS scale, below the range where scale is usually worth treating.
Water softener cost for an estimated 0.2 gpg water in Sonora — equipment and local installation labour for your ZIP code, with the sizing arithmetic shown in full. For the national picture first, read what a water softener costs — equipment, installation labour and ten-year ownership, each separated out. For California as a whole, read water softener cost in California — priced against the plumber wage published for the state.
Frequently Asked Questions About Sonora Tap Water
No test results on file for TUD - TUOLUMNE WATER SYSTEM, Sonora's water system. Results from other water systems on this page are listed under each system's name; they are not TUD - TUOLUMNE WATER SYSTEM's results and do not make a verdict for Sonora. Check TUD - TUOLUMNE WATER SYSTEM's latest Consumer Confidence Report for its current test results.
Spotted something off on this page?
Residents keep our data honest.
This form corrects our data; it does not reach TUD - TUOLUMNE WATER SYSTEM. For a problem with your water now (discolored water, no water, low pressure, a leak), contact TUD - TUOLUMNE WATER SYSTEM directly.
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