WaterVerge

Is Corcoran, CA Tap Water Safe to Drink?

Graded A — but Chlorate was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓

23K residents served 1 water system PWSID: CA1610004
Overall Score
90.8 / 100
Violations
None active
Last Updated
May 2026
Source
Groundwater
#119 of 694 in California Top 13% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
AGRADE
Water Quality Grade
90.8/100
waterverge.com
A 90.8/100

Corcoran, CA — Water Quality Report

Corcoran's drinking water received a grade of A (90.8 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 22,808 residents using groundwater.

Lead levels were measured at 9.3 ppb (90th percentile), which is within EPA limits but above recommended levels. PFAS testing under UCMR 5 found no detectable forever chemicals.

The system has 10 violations on record, including 3 health-based violations. All violations have been resolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Corcoran's water

Corcoran ranks #119 out of 694 cities in California for water quality, placing it above average in the state.

Corcoran 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.

Hexavalent chromium (chromium-6) was detected at 0.97 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.

While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection.

Quality Breakdown

Water quality score

See methodology →
90.8 out of 100 Grade A
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
44.2/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
13/20
C
Lead at 9.3 ppb (90th percentile).
Contaminants
18.6/20
A
No PFAS compounds detected.
Compliance
10/10
A
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Corcoran, CA water safe to drink?

Generally Safe

Based on EPA testing data, Corcoran's tap water is generally safe to drink. The water system earned a grade of A (90.8/100), meeting federal drinking water standards across key contaminant categories. The city's 1 water system serves approximately 22,808 residents using groundwater (wells).

None
Violations
9.3 ppb
Lead (90th %ile)
None
PFAS Detected
9 events
Disaster History

Recent water quality updates for Corcoran

A timeline of significant water quality events, violations, and data updates.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Corcoran's water quality assessment. Grade: A (90.8/100).

Disaster
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES

Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.

Disaster
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES

Federal disaster declaration (FEMA DR-3591). Flood event — may have impacted local water infrastructure.

Violation
2 drinking water violations recorded

Contaminants: Total Haloacetic Acids (HAA5), TTHM.

Violation
1 drinking water violation recorded

Contaminants: Coliform (TCR).

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Coliform (TCR).

Key contaminant findings

Based on the most recent EPA sampling data for Corcoran's water supply.

Lead Elevated
Detected: 9.3 ppb Limit: 15 ppb (EPA Action Level)

Within EPA limits but above the American Academy of Pediatrics recommended level of 1 ppb. An NSF 53-certified filter provides additional protection.

Violation history

Corcoran's water system has 10 total violations on record, including 3 health-based violations. All violations have been resolved.

MRMCL
Most recent violations:
Jan 2014 Total Haloacetic Acids (HAA5) Resolved
Jan 2014 TTHM Resolved
Apr 2011 Coliform (TCR) Resolved
Jul 2010 Coliform (TCR) Resolved
Oct 2004 TTHM Resolved

Flood & environmental risk

Kings County has experienced 9 federally declared disasters since 1969. 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 Cross C A Kansas Ave Nr Hanford.

SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA DR-3592
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA DR-3591
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA DR-4308

Where does Corcoran's water come from?

Corcoran's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 22,808 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Cross C A Kansas Ave Nr Hanford (river).

What Corcoran residents can do

Request your utility's CCR

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.

Flush your taps

Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.

Monitor alerts during storms

Corcoran'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.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
9.3 ppb
EPA Action Level: 15 ppb · 62% of limit
Safe Level
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
9.4 µg/L
EPA MCL: 60 µg/L · 16% of limit
Within LimitUCMR 4 DataHAA6Br: 9.1 µg/LHAA9: 16.5 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Detected
0.97 µg/L
CA MCL (no federal MCL): 10 µg/L · 10% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Detected
110.0 µg/L
EPA Health Ref Level: 1,500 µg/L · 7% of limit
DetectedUCMR 3 Data
Manganese
Inorganic
Detected
1.4 µg/L
EPA Secondary MCL: 50 µg/L · 3% of limit
DetectedUCMR 4 Data
Vanadium
Inorganic
Detected
4.20 µg/L
EPA Short-term HA: 21 µg/L · 20% of limit
DetectedUCMR 3 Data
Chlorate
Disinfection Byproduct
Over HA
330.0 µg/L
EPA Lifetime HA: 210 µg/L · +20% over limit
Over Health AdvisoryUCMR 3 Data
Molybdenum
Inorganic
Detected
5.90 µg/L
EPA Lifetime HA: 40 µg/L · 15% of limit
DetectedUCMR 3 Data
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
0
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

10
Total violations
3
Health-based
0
Active / unresolved
Jan 2014
Most recent violation
Compliance Record

Violations & advisories

10 Total
0 Active
3 Health-based
10 Resolved
Violations by category
Total Coliform Rule
5
Stage 2 Disinfectants and Disinfection Byproducts Rule
2
Stage 1 Disinfectants and Disinfection Byproducts Rule
2
Nitrate Rule
1
Jan 2014 Resolved
Total Haloacetic Acids (HAA5)
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 2014
Jan 2014 Resolved
TTHM
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 2014
Apr 2011 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved Apr 2011
Jul 2010 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Jul 2010
Oct 2004 Resolved
TTHM
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
Oct 2004 Resolved
Total Haloacetic Acids (HAA5)
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2004
May 2003 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved May 2003
May 2003 Resolved
Coliform (TCR)
Monitoring & Reporting
Monitoring & Reporting Resolved May 2003
Jan 2000 Resolved
Nitrate
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2000
Jul 1993 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Jul 1993
Industrial pollution

Top industrial polluters within 10 miles of Corcoran

Industrial polluters nearby

Reported releases to surface water by facilities near Corcoran, ranked by pounds discharged annually.

FacilityTop chemicalTo surface water (lbs/yr)Distance
JG BOSWELL CO OIL MILL
Food · JG BOSWELL CO
CORCORAN, CA93212
0.5 mi
J.G. BOSWELL CO - KINGS TOMATO
Food · JG BOSWELL CO
CORCORAN, CA93212
1.4 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Environmental Risk

Flood & disaster history

9
Declared disasters
Mar 2023
Most recent
Flood
Most common type

Kings County has experienced 9 federally declared disasters since 1969. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Mar 2023
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA #3592
Jan 2023
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA #3591
Apr 2017
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA #4308
Jan 2011
SEVERE WINTER STORMS, FLOODING, AND DEBRIS AND MUD FLOWS
Flood FEMA #1952
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3248
Feb 1983
COASTAL STORMS, FLOODS, SLIDES & TORNADOES
Coastal Storm FEMA #677

Recommended water filters

Based on contaminants detected in Corcoran's water supply, we recommend the following filter types.

🚰
For Lead
Reverse Osmosis or NSF 53-Certified Pitcher
Lead detected at 9.3 ppb
Read our guide →

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 9.3 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium ND HI µg/L PFAS Not Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has increased by 5.3 ppb from 1992 (4.0 ppb) to 2024 (9.3 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Local Government
Population Served
22,808
Water Systems
1
Water Source

Where Corcoran's water comes from

Groundwater

Corcoran'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 22,808 people through 1 water system.

Local Hydrology

Water bodies near Corcoran

Corcoran is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

Cross C A Kansas Ave Nr Hanford
river
Infrastructure

Water systems serving Corcoran

System Name PWSID Population Source
CORCORAN, CITY OF CA1610004 22,808 GW
Regional Comparison

How Corcoran compares

Full California rankings →

Corcoran's score of 90.8/100 is above the average of 57/100 among major California cities. It outscores 9 of 10 nearby cities.

Corcoran (this city)
90.8
Oakland
77.9
San Diego
39.7
Sacramento
31.2
California avg
57
City Profile

About Corcoran, CA

Economic Profile
$53,103
Median Income
$207,052
Median Home Value
$994/mo
Median Rent
11.2%
Unemployment
Community
34
Median Age
1,181
People / sq mi
3.9%
College Educated
51.3%
Homeownership
Share this reportHelp others learn about their water quality
WhatsAppXFacebookLinkedInEmail

Frequently asked questions

Is Corcoran, CA tap water safe to drink?

Corcoran's water quality earned a grade of A (90.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #119 out of 694 cities tested in California.

What contaminants are in Corcoran's water?

Lead was measured at 9.3 ppb (90th percentile). No PFAS compounds were detected. 10 violations are on record.

How is Corcoran'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 Corcoran?

While lead levels are within EPA limits, a filter adds extra protection. Based on current data, basic filtration should suffice for additional peace of mind.

Where does Corcoran's water come from?

Corcoran's water is sourced from Groundwater. The city has 1 water system serving approximately 22,808 residents.

What health violations has Corcoran's water system had?

Corcoran has 3 health-based violations on record. The most recent violation was recorded in January 2014. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. All health violations have been resolved.

Is Corcoran's groundwater at risk of contamination?

Corcoran 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 10 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 Corcoran's water compare to other cities?

Corcoran ranks #119 out of 694 cities in California (better than 83% of state cities) and #2005 out of 15744 cities nationally (87th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.