Modesto Tap Water Quality Report
Modesto's water has 3 contaminants above EPA MCLGs. Consider using a certified water filter for additional protection.
Other systems listed for Modesto with results above guidelines: COUNTRY VILLA APTS (1 above guidelines), RIVERVIEW MOBILE HOME ESTATES (1 above guidelines), MODESTO IRRIGATION DISTRICT (1 above guidelines), COUNTRY WESTERN MOBILE HOME PARK (1 above guidelines), HAKAM MISSON (3 above guidelines)
Water system
MODESTO, CITY OF
4 other systems also serve parts of Modesto. 12 other systems are listed for Modesto. See their figures
People Served
218,464
Health-based violations since 2020
0
MODESTO, CITY OF. EPA SDWA violation data as of Q2 2026 (downloaded 2026-07-09).
Latest sample on file
Aug 2024 · MODESTO, CITY OF
Utilities publish newer results in their annual water quality report (Consumer Confidence Report).
Is Modesto Tap Water Safe to Drink?
We recommend using a certified water filter for additional protection, especially for vulnerable populations like children, pregnant women, and those with compromised immune systems. Modesto's water has 3 contaminants above EPA health-based guidelines (MCLGs), while it meets federal legal limits.
MODESTO, CITY OF, Modesto's water system, serves 218,464 people. 4 other systems also serve parts of Modesto. 12 other systems are listed for Modesto. Each system's results are listed under its own name, never added to MODESTO, CITY OF's. Water quality testing is conducted regularly and reported to the EPA. The latest sample on file for MODESTO, CITY OF is from Aug 2024.
In EPA's 2023–2026 UCMR 5 testing, MODESTO, CITY OF measured lithium at up to 21 µg/L, which EPA counts as above its health reference level of 10 µg/L. That level is a screening value EPA uses to decide what to study further, not a legal limit, and this result does not change this page's water-quality summary.
Boil water advisories are issued by water systems and state agencies, and they change from day to day. Boil water advisories in California
Modesto Water Service Areas
What these numbers actually mean for Modesto, CA
We read Modesto, CA’s published record and send you a short report — which findings warrant a decision, which to ignore, and what to do about it. Including when the answer is nothing.
- 3 contaminants above EPA MCLGs and 14 contaminants with an EPA health goal detected in some samples (no level on file)
- 123 results on file
- 23 PFAS compounds on record
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Recommended Water Filters for Modesto
Based on Modesto's water quality data, these NSF-certified filters are recommended to remove contaminants above EPA MCLGs.
Culligan
ZeroWater
NSF Certified:
Flow Rate
1.9 gpm
Daily Production
1 gpd
Highlights:
- Compact design
- Easy to set up
- Affordable
- NSF-42, NSF-53, NSF-401 certified
Removes 19 contaminants:
+14 more
Strontium, Molybdenum, Fluoride, Uranium, Lead, Total PFAS, Chlorine, 25, Phosphorus, Bicarbonate, Calcium, Carbonate, Magnesium, Sodium
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:
Waterdrop
A1
NSF Certified:
Flow Rate
1 gpm
Highlights:
- Performance certified
- Lower price than Philips
- Hot water dispensing
- Compact design
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
Verify Your Water Quality with Independent Testing
With 3 contaminants above EPA MCLGs and 14 contaminants with an EPA health goal detected in some samples (no level on file), independent laboratory testing provides a second opinion and can track changes over time.
SimpleLab
Advanced Home Water Test
$269
Comprehensive water analysis testing over 200 contaminants including bacteria, heavy metals, and chemical compounds.
Tap Score
PFAS Forever Chemicals Test
$339.95
Specialized test for PFOA, PFOS, and 24 other forever chemicals. Essential for areas near military bases, airports, or industrial sites.
Tap Score
Advanced Microplastics Test
$829
Cutting-edge testing for microplastics particles in drinking water using advanced laboratory techniques.
With 3 contaminants above health guidelines, you may want to explore water purification options. Learn how to make distilled water at home for applications like humidifiers, CPAP machines, and baby formula.
What Modesto's water readings can explain
Utility-reported data for Modesto includes sulfate and a chlorine-based disinfectant — the readings behind these common tap water questions. We publish a city-level hardness figure for Modesto, 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 Modesto? Public-water results do not apply to private wells. See Stanislaus County well water testing and USGS risk data — modeled arsenic, nitrate, and the tests to run.
Water softener cost and installation in Modesto
Modesto's tap water measures 2.6 grains per gallon (44.5 mg/L) — soft on the USGS scale, below the range where scale is usually worth treating.
Water softener cost for 2.6 gpg water in Modesto — 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 Modesto Tap Water
Modesto's water has 3 contaminants above EPA MCLGs. While the water meets federal legal limits, we recommend using a certified water filter for additional protection, especially for vulnerable populations like children, pregnant women, and those with compromised immune systems.
Spotted something off on this page?
Residents keep our data honest.
This form corrects our data; it does not reach MODESTO, CITY OF. For a problem with your water now (discolored water, no water, low pressure, a leak), contact MODESTO, CITY OF directly.
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