01The verdict: is Buttonwillow water safe?
Buttonwillow's drinking water has significant quality concerns based on EPA testing data. With a grade of A (91.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 1,534 residents using groundwater (wells).
7 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 0.7 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 ↓Buttonwillow's drinking water received a grade of A (91.5 out of 100), indicating excellent water quality. The city's 2 water systems serve approximately 1,534 residents using groundwater.
Lead levels were measured at 0.7 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 36 violations on record, including 14 health-based violations. 7 remain unresolved.
Buttonwillow ranks #107 out of 690 cities in California for water quality, placing it above average in the state. Buttonwillow 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, Buttonwillow may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Buttonwillow's water
Every contaminant flagged in Buttonwillow, 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. | 0.7 | 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
03Buttonwillow'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 36 violations on record, including 14 health-based violations. 7 remain unresolved.
All ten of the last ten years were clean — no EPA violations recorded for Buttonwillow.
▼ Down 0 ppb since 1995. Latest reading: 0 ppb (2025) — 0% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Buttonwillow's water comes from
Buttonwillow'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.
2 systems
2 water systems, operated under local government ownership.
1,534 people
Residents served across Buttonwillow'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 1,534 people through 2 water systems.
| System name | PWSID | Population | Source |
|---|---|---|---|
| BUTTONWILLOW CWD | CA1510011 | 1,508 | Groundwater |
| MIRASOL COMPANY WATER SYSTEM | CA1500152 | 26 | Groundwater |
05Pressure on Buttonwillow'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
3 facilities within 10 miles reported 0 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 Kern County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Buttonwillow compares
Scores for nearby California cities on one line, with the average marked.
dashed line = California average (57/100)
Buttonwillow scores 91.5/100 — above the California average of 57/100. It outscores 9 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 Buttonwillow's water — not generic advice.
A basic carbon filter still helps
Buttonwillow'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 Buttonwillow 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 Buttonwillow, CA tap water safe to drink?
Buttonwillow's water quality earned a grade of A (91.5/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #107 out of 690 cities tested in California.
What contaminants are in Buttonwillow's water?
Lead was measured at 0.7 ppb (90th percentile). 36 violations are on record.
How is Buttonwillow'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 Buttonwillow?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Buttonwillow's water come from?
Buttonwillow's water is sourced from Groundwater. The city has 2 water systems serving approximately 1,534 residents.
What health violations has Buttonwillow's water system had?
Buttonwillow has 14 health-based violations on record. The most recent violation was recorded in January 2015. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 7 violations remain unresolved.
Is Buttonwillow's groundwater at risk of contamination?
Buttonwillow 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 36 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 Buttonwillow's water compare to other cities?
Buttonwillow ranks #107 out of 690 cities in California (better than 84% of state cities) and #1657 out of 15382 cities nationally (89th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.