WaterVerge

Is Corning, CA Tap Water Safe to Drink?

Graded B-, with 10 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

9K residents served 4 water systems PWSID: CA5210001
Overall Score
71 / 100
Violations
10 active
Last Updated
May 2026
Source
Groundwater
#502 of 694 in California Top 68% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
B-GRADE
Water Quality Grade
71/100
waterverge.com
B- 71/100

Corning, CA — Water Quality Report

Corning's drinking water received a grade of B- (71 out of 100), indicating fair water quality. The city's 4 water systems serve approximately 8,541 residents using groundwater.

Lead levels were measured at 1.1 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 59 violations on record, including 17 health-based violations. 10 remain unresolved.

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

What to know about Corning's water

Corning ranks #502 out of 694 cities in California for water quality, placing it below average in the state.

Corning 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.

PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.

The system has seen 8 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
71 out of 100 Grade B-
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
19.8/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 1.1 ppb (90th percentile).
Contaminants
18.2/20
A
1 PFAS compound detected.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Corning, CA water safe to drink?

Concerns Identified

Corning's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (71/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 8,541 residents using groundwater (wells).

10
Active Violations
1.1 ppb
Lead (90th %ile)
1 compound
PFAS Detected
10 events
Disaster History

Recent water quality updates for Corning

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

PFAS
1 PFAS "forever chemical" compound detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Corning's water quality assessment. Grade: B- (71/100).

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Violation
1 drinking water violation recorded

Contaminants: LEAD AND COPPER RULE REVISIONS.

Violation
6 drinking water violations recorded

3 health-based. Contaminants: LEAD AND COPPER RULE REVISIONS.

Disaster
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES

Federal disaster declaration (FEMA DR-4683). Flood event — may have impacted local water infrastructure.

Key contaminant findings

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

Lead Within Limits
Detected: 1.1 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 10.2000 µg/L Limit: 0.004 µg/L (EPA MCL)

Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.

Violation history

Corning's water system has 59 total violations on record, including 17 health-based violations. 10 remain unresolved. 8 violations were issued in the last 5 years.

MRRPTTTMCLOther
Most recent violations:
Oct 2025 Lead and Copper Rule Open
Jul 2025 LEAD AND COPPER RULE REVISIONS Open
Oct 2024 LEAD AND COPPER RULE REVISIONS Open
Oct 2024 LEAD AND COPPER RULE REVISIONS Open
Oct 2024 LEAD AND COPPER RULE REVISIONS Open

Flood & environmental risk

Tehama County has experienced 10 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.

SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA DR-4683
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA DR-3591
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA DR-4308

Where does Corning's water come from?

Corning's drinking water comes from groundwater (wells), supplied by 4 water systems serving approximately 8,541 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.

What Corning residents can do

Install a water filter

Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in Corning's water.

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.

Monitor alerts during storms

Corning'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
1.1 ppb
EPA Action Level: 15 ppb · 7% of limit
Safe Level
lithium
PFAS / Forever Chemical
Near MCL
10.2000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
Lithium
Inorganic
Detected
10.2 µg/L
State screening level: 60 µg/L · 17% of limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
1
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

59
Total violations
17
Health-based
10
Active / unresolved
Oct 2025
Most recent violation
Compliance Record

Violations & advisories

59 Total
10 Active
17 Health-based
49 Resolved
Violations by category
Miscellaneous Other Rules
30
Total Coliform Rule
14
Lead and Copper Rule Revisions
7
Radionuclides and Revised Rad Rule
4
Lead and Copper Rule
2
Oct 2025 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2025 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Active
Compliance Violation
Monitoring 0
Active
Compliance Violation
Monitoring 0
Dec 2014 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Dec 2014
Oct 2013 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Oct 2013
Feb 2004 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Feb 2004
Jul 2002 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Jul 2002
May 2002 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved May 2002
Jun 2000 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Jun 2000
Nov 1997 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Nov 1997
Nov 1994 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Nov 1994
Oct 1994 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Oct 1994
Nov 1993 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Nov 1993
Showing 20 of 59 violations
Environmental Risk

Flood & disaster history

10
Declared disasters
Jan 2023
Most recent
Flood
Most common type

Tehama County has experienced 10 federally declared disasters since 1969. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Jan 2023
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA #4683
Jan 2023
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA #3591
Apr 2017
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA #4308
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3248
Feb 1993
SEVERE WINTER STORM, MUD & LAND SLIDES, & FLOODING
Flood FEMA #979
Feb 1986
SEVERE STORMS & FLOODING
Flood FEMA #758

Recommended water filters

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

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
1 PFAS compound detected

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 1.1 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 10.200 HI µg/L PFAS 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 decreased by 1.4 ppb from 1992 (2.5 ppb) to 2025 (1.1 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Local Government
Population Served
8,541
Water Systems
4
Water Source

Where Corning's water comes from

Groundwater

Corning'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 8,541 people through 4 water systems.

Infrastructure

Water systems serving Corning

System Name PWSID Population Source
CITY OF CORNING CA5210001 8,244 GW
MAYWOOD MOBILE HOME PARK CA5200556 140 GW
CORNING RV PARK CA5200255 112 GW
WOODSON BRIDGE RV PARK CA5200010 45 GW
Regional Comparison

How Corning compares

Full California rankings →

Corning's score of 71/100 is above the average of 57/100 among major California cities. It outscores 7 of 10 nearby cities.

Corning (this city)
71
Oakland
77.9
San Diego
39.7
Sacramento
31.2
California avg
57
City Profile

About Corning, CA

Economic Profile
$54,766
Median Income
$245,124
Median Home Value
$1,060/mo
Median Rent
3.6%
Unemployment
Community
33.3
Median Age
892
People / sq mi
10.2%
College Educated
52.2%
Homeownership
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Frequently asked questions

Is Corning, CA tap water safe to drink?

Corning's water quality earned a grade of B- (71/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #502 out of 694 cities tested in California.

What contaminants are in Corning's water?

Lead was measured at 1.1 ppb (90th percentile). 1 PFAS compound was detected. 59 violations are on record.

How is Corning'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 Corning?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does Corning's water come from?

Corning's water is sourced from Groundwater. The city has 4 water systems serving approximately 8,541 residents.

What health violations has Corning's water system had?

Corning has 17 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 10 violations remain unresolved.

Is Corning's groundwater at risk of contamination?

Corning 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 59 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 Corning's water compare to other cities?

Corning ranks #502 out of 694 cities in California (better than 28% of state cities) and #10636 out of 15744 cities nationally (32th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.