01The verdict: is Arrowbear Lake water safe?
Based on EPA testing data, Arrowbear Lake's tap water is generally safe to drink. The water system earned a grade of A (94.7/100), meeting federal drinking water standards across key contaminant categories. The city's 1 water system serves approximately 1,856 residents using groundwater (wells).
Nothing over a legal limit
Every contaminant measured in Arrowbear Lake's water is within its EPA limit, and no violations are unresolved.
See the testing ↓Lead is well under the limit
90th-percentile lead is 5.0 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓A flood-prone service area
10 federal disaster declarations on record. After severe weather, watch for boil-water advisories.
See the risk factors ↓Arrowbear Lake's drinking water received a grade of A (94.7 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 1,856 residents using groundwater.
Lead levels were measured at 5.0 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 4 violations on record, including 1 health-based violation. All violations have been resolved.
Arrowbear Lake ranks #45 out of 690 cities in California for water quality, placing it one of the best in the state. Arrowbear Lake 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, Arrowbear Lake may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Arrowbear Lake's water
Every contaminant flagged in Arrowbear Lake, 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. | 5.0 | 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
03Arrowbear Lake'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 4 violations on record, including 1 health-based violation. All violations have been resolved.
All ten of the last ten years were clean — no EPA violations recorded for Arrowbear Lake.
▼ Down 13 ppb since 1993. Latest reading: 5 ppb (2023) — 33% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Arrowbear Lake's water comes from
Arrowbear Lake'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.
1 system
1 water system, operated under local government ownership.
1,856 people
Residents served across Arrowbear Lake'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 local government ownership and serves approximately 1,856 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| ARROWBEAR PARK CWD | CA3610110 | 1,856 | Groundwater |
Water bodies near Arrowbear Lake
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Arrowbear Lake'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.
Flood & storm history
10 federal disaster declarations on record for San Bernardino County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
San Bernardino County is in D1 (moderate drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Arrowbear Lake compares
Scores for nearby California cities on one line, with the average marked.
dashed line = California average (57/100)
Arrowbear Lake scores 94.7/100 — above the California average of 57/100. It outscores 10 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 Arrowbear Lake's water — not generic advice.
A basic carbon filter still helps
Arrowbear Lake'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 →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Arrowbear Lake 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 Arrowbear Lake, CA tap water safe to drink?
Arrowbear Lake's water quality earned a grade of A (94.7/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #45 out of 690 cities tested in California.
What contaminants are in Arrowbear Lake's water?
Lead was measured at 5.0 ppb (90th percentile). 4 violations are on record.
How is Arrowbear Lake'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 Arrowbear Lake?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Arrowbear Lake's water come from?
Arrowbear Lake's water is sourced from Groundwater. The city has 1 water system serving approximately 1,856 residents.
What health violations has Arrowbear Lake's water system had?
Arrowbear Lake has 1 health-based violation on record. The most recent violation was recorded in November 2009. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. All health violations have been resolved.
Is Arrowbear Lake's groundwater at risk of contamination?
Arrowbear Lake 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 4 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 Arrowbear Lake's water compare to other cities?
Arrowbear Lake ranks #45 out of 690 cities in California (better than 93% of state cities) and #442 out of 15382 cities nationally (97th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Arrowbear Lake's small water system affect quality?
Arrowbear Lake's system serves approximately 1,856 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 4 violations on record.