01The verdict: is Yorba Linda water safe?
Yorba Linda's drinking water has significant quality concerns based on EPA testing data. With a grade of B (75.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 8 water systems serve approximately 1,729 residents using groundwater (wells).
8 unresolved violations on record
EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓Lead is well under the limit
90th-percentile lead is 0.6 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓7 violations in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓Yorba Linda's drinking water received a grade of B (75.5 out of 100), indicating good water quality. The city's 8 water systems serve approximately 1,729 residents using groundwater.
Lead levels were measured at 0.6 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 87 violations on record, including 38 health-based violations. 8 remain unresolved.
Yorba Linda ranks #451 out of 690 cities in California for water quality, placing it below average in the state. Yorba Linda 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, Yorba Linda may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 7 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
02What's in Yorba Linda's water
Every contaminant flagged in Yorba Linda, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
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. | 0.6 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in California
Cities ranked by compounds detected Cu Copper in California
Cities ranked by 90th-percentile copper
03Yorba Linda's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 87 violations on record, including 38 health-based violations. 8 remain unresolved.
8 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▼ Down 59 ppb since 1992. Latest reading: 0 ppb (2025) — 0% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Yorba Linda's water comes from
Yorba Linda's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
8 systems
8 water systems, operated under private ownership.
1,729 people
Residents served across Yorba Linda's service area.
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 1,729 people through 8 water systems.
| System name | PWSID | Population | Source |
|---|---|---|---|
| OAK GLEN RETREAT | CA3600133 | 576 | Groundwater |
| SONORA ESTATES MOBILE HOME PARK | CA5500086 | 235 | Groundwater |
| DINGERVILLE USA PARK | CA0400051 | 220 | Groundwater |
| APPLE VALLEY VILLAGE MHE | CA3600400 | 180 | Groundwater |
| CAL ORE MOBILE ESTATES | CA4700546 | 146 | Groundwater |
| OAKHURST MOBILE HOME ESTATES | CA2000593 | 138 | Groundwater |
| ABRAMS LAKE MOBILE ESTATES | CA4700542 | 135 | Groundwater |
| BEND MOBILEHOME & RV PARK | CA5200512 | 99 | Groundwater |
Water bodies near Yorba Linda
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Yorba Linda's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Industrial discharge
5 facilities within 10 miles reported 14 lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.
Flood & storm history
10 federal disaster declarations on record for Orange County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Superfund proximity
1 National Priorities List site within 10 miles. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
06How Yorba Linda compares
Scores for nearby California cities on one line, with the average marked.
dashed line = California average (57/100)
Yorba Linda scores 75.5/100 — above the California average of 57/100. It outscores 7 of 10 nearby cities. Full California rankings →
42.8 / 100FSan Jose, CA
28 / 100BOakland, CA
77.9 / 100FSan Diego, CA
39.7 / 100FSacramento, CA
31.2 / 100ABurlingame, CA
89.2 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Yorba Linda's water — not generic advice.
A basic carbon filter still helps
Yorba Linda's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.
Compare tested filters →Read your utility's annual report
Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.
How to read a CCR →Watch for Yorba Linda alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Yorba Linda, CA tap water safe to drink?
Yorba Linda's water quality earned a grade of B (75.5/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #451 out of 690 cities tested in California.
What contaminants are in Yorba Linda's water?
Lead was measured at 0.6 ppb (90th percentile). 87 violations are on record.
How is Yorba Linda'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 Yorba Linda?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Yorba Linda's water come from?
Yorba Linda's water is sourced from Groundwater. The city has 8 water systems serving approximately 1,729 residents.
What health violations has Yorba Linda's water system had?
Yorba Linda has 38 health-based violations on record. The most recent violation was recorded in September 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 8 violations remain unresolved.
Is Yorba Linda's groundwater at risk of contamination?
Yorba Linda 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 87 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 Yorba Linda's water compare to other cities?
Yorba Linda ranks #451 out of 690 cities in California (better than 35% of state cities) and #9456 out of 15382 cities nationally (39th percentile). The grade of B reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.