Is Palomar Mountain, CA Tap Water Safe to Drink?
Graded A, with 1 unresolved violation on record. See what was cited — and what it means for your tap. What to do next ↓
93.4/100
waterverge.com Palomar Mountain, CA — Water Quality Report
Palomar Mountain's drinking water received a grade of A (93.4 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 4,416 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 16 violations on record, including 1 health-based violation. 1 remains unresolved.
What to know about Palomar Mountain's water
Palomar Mountain ranks #71 out of 694 cities in California for water quality, placing it above average in the state.
Palomar Mountain 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.
Water quality score
See methodology →Is Palomar Mountain, CA water safe to drink?
Palomar Mountain's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (93.4/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 4,416 residents using groundwater (wells).
Recent water quality updates for Palomar Mountain
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Palomar Mountain's water quality assessment. Grade: A (93.4/100).
Federal disaster declaration (FEMA DR-4758). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-4683). Flood event — may have impacted local water infrastructure.
Contaminants: Revised Total Coliform Rule.
Contaminants: Revised Total Coliform Rule.
Contaminants: Coliform (TCR).
Key contaminant findings
Based on the most recent EPA sampling data for Palomar Mountain's water supply.
Well within EPA limits.
Violation history
Palomar Mountain's water system has 16 total violations on record, including 1 health-based violation. 1 remain unresolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
San Diego County has experienced 10 federally declared disasters since 1980. 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 Temecula C Nr Aguanga.
Where does Palomar Mountain's water come from?
Palomar Mountain's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 4,416 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Temecula C Nr Aguanga (river).
What Palomar Mountain residents can do
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.
Palomar Mountain'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
San Diego County has experienced 10 federally declared disasters since 1980. 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 Palomar Mountain compares by contaminant
Explore where Palomar Mountain ranks among all California cities for specific contaminants.
Water source & infrastructure
Where Palomar Mountain's water comes from
Palomar Mountain'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 state ownership and serves approximately 4,416 people through 1 water system.
Water bodies near Palomar Mountain
Palomar Mountain is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Palomar Mountain
| System Name | PWSID | Population | Source |
|---|---|---|---|
| PALOMAR OBSERVATORY | CA3702236 | 4,416 | GW |
How Palomar Mountain compares
Full California rankings →Palomar Mountain's score of 93.4/100 is above the average of 57/100 among major California cities. It outscores 10 of 10 nearby cities.
Nearby cities
View California rankings →About Palomar Mountain, CA
Wikipedia →Palomar Mountain is an unincorporated community in San Diego County, California.
Learn more about your water
Guides and resources related to Palomar Mountain's water quality findings.
Explore water quality across San Diego
Frequently asked questions
Is Palomar Mountain, CA tap water safe to drink?
Palomar Mountain's water quality earned a grade of A (93.4/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #71 out of 694 cities tested in California.
What contaminants are in Palomar Mountain's water?
Lead was measured at 0.0 ppb (90th percentile). 16 violations are on record.
How is Palomar Mountain'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 Palomar Mountain?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Palomar Mountain's water come from?
Palomar Mountain's water is sourced from Groundwater. The city has 1 water system serving approximately 4,416 residents.
What health violations has Palomar Mountain's water system had?
Palomar Mountain has 1 health-based violation on record. The most recent violation was recorded in November 2022. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
Is Palomar Mountain's groundwater at risk of contamination?
Palomar Mountain 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 16 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 Palomar Mountain's water compare to other cities?
Palomar Mountain ranks #71 out of 694 cities in California (better than 90% of state cities) and #844 out of 15744 cities nationally (95th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.