Is San Ardo, CA Tap Water Safe to Drink?
Graded A-, with 3 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
88.2/100
waterverge.com San Ardo, CA — Water Quality Report
San Ardo's drinking water received a grade of A- (88.2 out of 100), indicating good water quality. The city's 1 water system serves approximately 575 residents using groundwater.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 15 violations on record, including 4 health-based violations. 3 remain unresolved.
What to know about San Ardo's water
San Ardo ranks #198 out of 694 cities in California for water quality, placing it mid-range in the state.
San Ardo relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, San Ardo may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is San Ardo, CA water safe to drink?
San Ardo's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (88.2/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 575 residents using groundwater (wells).
Recent water quality updates for San Ardo
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into San Ardo's water quality assessment. Grade: A- (88.2/100).
1 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS.
Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4683). Flood event — may have impacted local water infrastructure.
Contaminants: Nitrate.
1 health-based. Contaminants: Coliform (TCR).
Key contaminant findings
Based on the most recent EPA sampling data for San Ardo's water supply.
Well within EPA limits.
Violation history
San Ardo's water system has 15 total violations on record, including 4 health-based violations. 3 remain unresolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
Monterey County has experienced 10 federally declared disasters since 1967. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Salinas R Nr Bradley.
Where does San Ardo's water come from?
San Ardo's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 575 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Salinas R Nr Bradley (river).
What San Ardo residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in San Ardo's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
San Ardo's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Flood & disaster history
Monterey County has experienced 10 federally declared disasters since 1967. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how San Ardo compares by contaminant
Explore where San Ardo ranks among all California cities for specific contaminants.
Water source & infrastructure
Where San Ardo's water comes from
San Ardo's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by private ownership and serves approximately 575 people through 1 water system.
Water bodies near San Ardo
San Ardo is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving San Ardo
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SAN ARDO WD | CA2700728 | 575 | GW |
How San Ardo compares
Full California rankings →San Ardo's score of 88.2/100 is above the average of 57/100 among major California cities. It outscores 8 of 10 nearby cities.
Nearby cities
View California rankings →About San Ardo, CA
Learn more about your water
Guides and resources related to San Ardo's water quality findings.
Explore water quality across Monterey
Frequently asked questions
Is San Ardo, CA tap water safe to drink?
San Ardo's water quality earned a grade of A- (88.2/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #198 out of 694 cities tested in California.
What contaminants are in San Ardo's water?
Lead was measured at 0.0 ppb (90th percentile). 15 violations are on record.
How is San Ardo's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in San Ardo?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does San Ardo's water come from?
San Ardo's water is sourced from Groundwater. The city has 1 water system serving approximately 575 residents.
What health violations has San Ardo's water system had?
San Ardo has 4 health-based violations on record. The most recent violation was recorded in October 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.
Is San Ardo's groundwater at risk of contamination?
San Ardo uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 15 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does San Ardo's water compare to other cities?
San Ardo ranks #198 out of 694 cities in California (better than 71% of state cities) and #3615 out of 15744 cities nationally (77th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does San Ardo's small water system affect quality?
San Ardo's system serves approximately 575 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 15 violations on record.