Is San Simeon, CA Tap Water Safe to Drink?
Graded B- — but Lead was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
74.2/100
waterverge.com San Simeon, CA — Water Quality Report
San Simeon's drinking water received a grade of B- (74.2 out of 100), indicating fair water quality. The city's 2 water systems serve approximately 601 residents using groundwater.
Lead levels were measured at 45.0 ppb (90th percentile), which exceeds the EPA action level of 15 ppb. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 5 violations on record, including 3 health-based violations. All violations have been resolved.
What to know about San Simeon's water
San Simeon ranks #466 out of 694 cities in California for water quality, placing it below average in the state.
San Simeon 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.
Lead levels exceed the EPA action level of 15 ppb, which typically indicates aging lead service lines or lead solder in the distribution system. An NSF 53-certified filter is strongly recommended for drinking and cooking water.
As a small community water system, San Simeon may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is San Simeon, CA water safe to drink?
San Simeon's tap water meets most EPA standards but has areas that warrant attention. With a grade of B- (74.2/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 2 water systems serve approximately 601 residents using groundwater (wells).
Recent water quality updates for San Simeon
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into San Simeon's water quality assessment. Grade: B- (74.2/100).
1 health-based. Contaminants: Surface Water Treatment Rule.
1 health-based. Contaminants: Surface Water Treatment Rule.
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.
1 health-based. Contaminants: Surface Water Treatment Rule.
Key contaminant findings
Based on the most recent EPA sampling data for San Simeon's water supply.
Exceeds EPA action level. Lead service line replacement and point-of-use filtration recommended.
Violation history
San Simeon's water system has 5 total violations on record, including 3 health-based violations. All violations have been resolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
San Luis Obispo County has experienced 10 federally declared disasters since 1973. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does San Simeon's water come from?
San Simeon's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 601 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What San Simeon residents can do
Recommended: NSF 53-certified pitcher or under-sink filter. This addresses the specific contaminants found in San Simeon'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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
San Simeon'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 Luis Obispo County has experienced 10 federally declared disasters since 1973. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in San Simeon's water supply, we recommend the following filter types.
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. | 45.0 | 15 | ppb | Inorganic | Over Limit |
Lead level trend (90th percentile)
See how San Simeon compares by contaminant
Explore where San Simeon ranks among all California cities for specific contaminants.
Water source & infrastructure
Where San Simeon's water comes from
San Simeon'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 local government ownership and serves approximately 601 people through 2 water systems.
Water systems serving San Simeon
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SAN SIMEON CSD | CA4000568 | 462 | GW |
| GRAN CIELO MUTUAL WATER COMPANY | CA4000853 | 139 | GW |
How San Simeon compares
Full California rankings →San Simeon's score of 74.2/100 is above the average of 57/100 among major California cities. It outscores 7 of 10 nearby cities.
Nearby cities
View California rankings →About San Simeon, CA
Wikipedia →San Simeon is an unincorporated community on the Pacific coast of San Luis Obispo County, California, United States. As of the 2020 census, San Simeon had a population of 445. Its position along State Route 1 is about halfway between Los Angeles and San Francisco, each of those cities being roughly 230 miles (370 km) away. A key feature of the area is Hearst Castle, a hilltop mansion built for William Randolph Hearst in the early 20th century that is now a tourist attraction. The area is also home to a large northern elephant seal rookery, known as the Piedras Blancas rookery, located 7 miles (11 km) north of San Simeon on Highway 1.
Learn more about your water
Guides and resources related to San Simeon's water quality findings.
Explore water quality across San Luis Obispo
Frequently asked questions
Is San Simeon, CA tap water safe to drink?
San Simeon's water quality earned a grade of B- (74.2/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #466 out of 694 cities tested in California.
What contaminants are in San Simeon's water?
Lead was measured at 45.0 ppb (90th percentile). 5 violations are on record.
How is San Simeon'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 Simeon?
Yes — lead levels exceed the EPA action level of 15 ppb. We recommend an NSF 53-certified filter or reverse osmosis system. Based on current data, basic filtration should suffice for additional peace of mind.
Where does San Simeon's water come from?
San Simeon's water is sourced from Groundwater. The city has 2 water systems serving approximately 601 residents.
What health violations has San Simeon's water system had?
San Simeon has 3 health-based violations on record. The most recent violation was recorded in February 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. All health violations have been resolved.
Is San Simeon's groundwater at risk of contamination?
San Simeon 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 5 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 Simeon's water compare to other cities?
San Simeon ranks #466 out of 694 cities in California (better than 33% of state cities) and #9924 out of 15744 cities nationally (37th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.