CAL-WATER SERVICE CO.-CHICOlikely match

City water report · 2026

Is Chico Tap Water Safe? 2026 Water Quality Report

Short answer: Three PFAS, PFHxS, PFOA and PFOS, are above their federal limits (2024 limits that water systems have until at least 2029 to meet); lithium sits above a screening level. Cal-Water Service Co.-Chico serves 110,473 residents.

Explore the findings What can I do?Follow

Likely match, check your bill

CAL-WATER SERVICE CO.-CHICO serves Chico

Your water bill or annual water quality report names your actual supplier.

Source: Groundwater

CAL-WATER SERVICE CO.-CHICOThis report
CA0410002 · 110,473 served

What stands out

Three PFAS above the 2024 federal limit

Each bar is drawn in blocks of its own limit, so the length shows how far above it the result sits.

PFOS

Perfluorooctanesulfonic acid

5.6× the limit

22.5ng/L

Each block = 4.0 ng/L federal MCL (2024)

EPA UCMR 5 · sampled 2023Evidence

PFHxS

Perfluorohexanesulfonic acid

2.2× the limit

22.1ng/L

Each block = 10 ng/L federal MCL (2024)

EPA UCMR 5 · sampled 2023Evidence

PFOA

Perfluorooctanoic acid

1.7× the limit

6.8ng/L

Each block = 4.0 ng/L federal MCL (2024)

EPA UCMR 5 · sampled 2023Evidence

Coverage by group

31 results on record

PFAS (forever chemicals)
3 above · 3 detected · 23 not detected
Metals & lead
1 not detected
Disinfection by-productsNot monitored
Other
1 above

Every detected result

7 detected results, by distance from their limit

CAL-WATER SERVICE CO.-CHICO (EPA PWSID CA0410002) delivers groundwater to 110,473 residents. This report reflects 29 individual PFAS result(s) from the source UCMR5 observations and the latest Lead & Copper Rule 90th-percentile result. Water hardness and disinfectant type are pending the utility's own annual report.

Perfluorooctanesulfonic acid (PFOS)EPA UCMR 5 · 2023
4.0 ng/L federal MCL (2024)
22.5ng/L
Above limit
Perfluorohexanesulfonic acid (PFHxS)EPA UCMR 5 · 2023
10 ng/L federal MCL (2024)
22.1ng/L
Above limit
Perfluorooctanoic acid (PFOA)EPA UCMR 5 · 2023
4.0 ng/L federal MCL (2024)
6.8ng/L
Above limit
LithiumEPA UCMR 5 · 2023
10 µg/L EPA health reference level (screening, not a legal limit)
11.7µg/L
Above screening
Perfluorobutanesulfonic acid (PFBS)EPA UCMR 5 · 2023
2,000 ng/L EPA health advisory (screening, not a legal limit)
9.6ng/L
Within reference
Perfluorohexanoic acid (PFHxA)EPA UCMR 5 · 2023
400,000 ng/L Michigan EGLE state MCL (strictest US state)
6ng/L
Within reference
Perfluoropentanoic acid (PFPeA)EPA UCMR 5 · 2023
No federal or state limit; shown for transparency
5.3ng/L
Detected · no limit

24 other contaminants tested, none detected

11Cl-PF3OUdS
4:2 FTS
6:2 FTS
8:2 FTS
9Cl-PF3ONS
ADONA
HFPO-DA (GenX)
NEtFOSAA
NFDHA
NMeFOSAA
PFBA
PFDA
PFDoA
PFEESA
PFHpA
PFHpS
PFMBA
PFMPA
PFNA
PFPeS
PFTA
PFTrDA
PFUnA
Lead (90th percentile)

Track record

0health-based violations in the last 10 years

From EPA SDWIS. A clean violation history means no enforcement action was recorded; it does not cover contaminants without a limit.

Not in this recordDisinfection by-products weren't monitored in this dataset

No result is not a pass. Your utility's annual water quality report may list them, and a certified lab test covers your own tap.

What you can do

Test first, then treat what was found

01 · TestTest your own tap
A tap test can confirm levels at your home before you choose treatment.
Certified lab
How to test your tap →
02 · Treat PFASReverse osmosis, or carbon certified for PFAS
PFOS 22.5 ng/L, above the 4 ng/L limit (+5 more PFAS detected)
NSF/ANSI 58 or 53, with PFHxS/PFOA/PFOS/PFBS/PFHxA/PFPeA named on the listing
Treatment for PFAS →
03 · LithiumDepends on the contaminant
Lithium 11.7 µg/L, above the 10.0 µg/L EPA health reference level
The certifier's listing for each named contaminant
Treatment for Lithium →

Understand water treatment technologies →

Test your own tap

Screening tells you if something is worth a closer look; a lab result is the number you can act on.

As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure.

Screening: quick check, not lab-grade
Watersafe Drinking Water Test Kit
Silver Lake Research
Lead, bacteria, nitrate, copper, iron, chlorine, hardness and pH
- Turnaround: Minutes; the bacteria test can take up to 48 hours
What it can't tell you: Each test gives a yes/no or a rough range, not a lab number, and it cannot detect PFAS or arsenic.
Check price on Amazon
Lab-certified results
ETR Labs Basic Water Quality Test Kit
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
- Analyzed by Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638
- Turnaround: 2–4 business days after the lab receives it
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Check price on Amazon

When your results arrive, read them here →

Commercial

Certified for a concern found here

Each card names which Chico findings its current certification covers, and which it doesn't.

As an Amazon Associate, PurityMap earns from qualifying purchases. A product appears here only when a current certification record covers at least one identified concern; every concern stays listed. The retail offer is looked up afterwards and never changes which products appear or their order. Affiliate disclosure.

Under-Sink Filter

Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200)

PFOA: eligible, evidence match
PFOS: eligible, evidence match
Not established: PFHxS, Lithium, Perfluorobutanesulfonic acid (PFBS) and 2 more

Not suitable for (5)

Treating every tap in the home
A whole-home hard-water or scale problem
All PFAS: its evidence covers only the compounds it names
Anyone who can't plumb, drill or hire an installer
Renters who can't modify plumbing

See the evidence Check price on Amazon

Under-Sink Filter

Aquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M)

PFOA: eligible, evidence match
PFOS: eligible, evidence match
Not established: PFHxS, Lithium, Perfluorobutanesulfonic acid (PFBS) and 2 more

Not suitable for (5)

Treating every tap in the home
A whole-home hard-water or scale problem
All PFAS: its evidence covers only the compounds it names
Anyone who can't plumb, drill or hire an installer
Renters who can't modify plumbing

See the evidence Check price on Amazon

See all 9 products certified for a Chico concern →

Countertop System

Aquasana Clean Water Machine Countertop Filter (AQ-CWM2)

PFOA: eligible, evidence match
PFOS: eligible, evidence match
Not established: PFHxS, Lithium, Perfluorobutanesulfonic acid (PFBS) and 2 more

Not suitable for (3)

Treating every tap in the home
A whole-home hard-water or scale problem
All PFAS: its evidence covers only the compounds it names

See the evidence Check price on Amazon

Countertop System

Patriot Pure Ultimate Water Filtration System

PFOA: eligible, evidence match
PFOS: eligible, evidence match
Not established: PFHxS, Lithium, Perfluorobutanesulfonic acid (PFBS) and 2 more

Not suitable for (3)

Treating every tap in the home
A whole-home hard-water or scale problem
All PFAS: its evidence covers only the compounds it names

See the evidence Check price on Amazon

Countertop System

AquaTru Carafe Countertop Reverse-Osmosis Purifier (AT100)

PFOA: eligible, evidence match
PFOS: eligible, evidence match
Not established: PFHxS, Lithium, Perfluorobutanesulfonic acid (PFBS) and 2 more

Not suitable for (3)

Treating every tap in the home
A whole-home hard-water or scale problem
All PFAS: its evidence covers only the compounds it names

See the evidence Check price on Amazon

Countertop System

AquaTru Classic Countertop Reverse-Osmosis Purifier (AT2000)

PFOA: eligible, evidence match
PFOS: eligible, evidence match
Not established: PFHxS, Lithium, Perfluorobutanesulfonic acid (PFBS) and 2 more

Not suitable for (3)

Treating every tap in the home
A whole-home hard-water or scale problem
All PFAS: its evidence covers only the compounds it names

See the evidence Check price on Amazon

Under-Sink Filter

Waterdrop G3P600 Tankless Reverse-Osmosis System

PFOA: eligible, evidence match
PFOS: eligible, evidence match
Not established: PFHxS, Lithium, Perfluorobutanesulfonic acid (PFBS) and 2 more

Not suitable for (5)

Treating every tap in the home
A whole-home hard-water or scale problem
All PFAS: its evidence covers only the compounds it names
Anyone who can't plumb, drill or hire an installer
Renters who can't modify plumbing

See the evidence Check price on Amazon

Under-Sink Filter

Waterdrop G3P800 Tankless Reverse-Osmosis System

PFOA: eligible, evidence match
PFOS: eligible, evidence match
Not established: PFHxS, Lithium, Perfluorobutanesulfonic acid (PFBS) and 2 more

Not suitable for (5)

Treating every tap in the home
A whole-home hard-water or scale problem
All PFAS: its evidence covers only the compounds it names
Anyone who can't plumb, drill or hire an installer
Renters who can't modify plumbing

See the evidence Check price on Amazon

Refrigerator Filter

Whirlpool Filter 3 Refrigerator Water Filter (WHR3RXD1)

PFOA: eligible, evidence match
PFOS: eligible, evidence match
Not established: PFHxS, Lithium, Perfluorobutanesulfonic acid (PFBS) and 2 more

Not suitable for (3)

Treating every tap in the home
A whole-home hard-water or scale problem
All PFAS: its evidence covers only the compounds it names

See the evidence Check price on Amazon

Questions

Frequently asked questions

Is Chico tap water safe to drink?

PurityMap does not give a safe/unsafe verdict; it shows what the public records measured. For Chico, PFOS 22.5 ng/L (limit 4 ng/L), PFHxS 22.1 ng/L (limit 10 ng/L) and PFOA 6.8 ng/L (limit 4 ng/L) were measured above their limits in EPA's 2024 testing. CAL-WATER SERVICE CO.-CHICO (PWSID CA0410002) has a Purity Score of 57/100 (confidence: moderate), assessed at the water-system level and computed only from contaminants that were measured. Water can change in your own pipes, so a certified test is the only way to know what comes out of your tap.

Who provides tap water in Chico?

CAL-WATER SERVICE CO.-CHICO (PWS ID CA0410002) is the public water system on record for Chico, California, serving about 110,473 people. Confirm the utility on your water bill before acting on a specific finding.

Where does Chico get its drinking water?

Groundwater (primary source of record in EPA SDWIS).

Are PFAS "forever chemicals" in Chico's water?

Yes. In EPA's UCMR 5 testing (2023-09-18 to 2024-07-23), PFOS was measured at 22.5 ng/L against a 4 ng/L federal limit, PFHxS was measured at 22.1 ng/L against a 10 ng/L federal limit and PFOA was measured at 6.8 ng/L against a 4 ng/L federal limit. PFBS (9.6 ng/L, below the 2,000 ng/L EPA health advisory) and PFHxA (6 ng/L, below the 400,000 ng/L state limit) were also detected. PFPeA (5.3 ng/L) was also detected; it has no federal or state limit. Reverse osmosis and filters certified to NSF/ANSI 53 for PFOA/PFOS reduce them at the tap.

Is there lead in Chico's tap water?

Lead is not in Chico's current published record. Lead usually enters from a building's own pipes and fixtures, so a certified home test is the way to know yours.

What does the latest Chico water report show?

PurityMap's current record for Chico holds 31 findings: 4 above a reference, 2 detected within the reference, 1 detected with no limit and 24 not detected. Each finding links to its dated public record; a parameter that was never monitored is shown as pending, not as a pass.

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Sources and dataAll 31 records and their sourcesEPA UCMR 5 · EPA SDWIS (Lead & Copper Rule)

Contaminant	Result	Benchmark	Status	Sampled	Source
Perfluorooctanesulfonic acid (PFOS)	22.5 ng/L	4.0 ng/L federal MCL (2024)	Above a historical reference; current applicability unverified	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorohexanesulfonic acid (PFHxS)	22.1 ng/L	10 ng/L federal MCL (2024)	Above a historical reference; current applicability unverified	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorooctanoic acid (PFOA)	6.8 ng/L	4.0 ng/L federal MCL (2024)	Above a historical reference; current applicability unverified	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Lithium	11.7 µg/L	10 µg/L EPA health reference level (screening, not a legal limit)Screening level, not a legal limit	Above the referenced health-based guidance value	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorobutanesulfonic acid (PFBS)	9.6 ng/L	2,000 ng/L EPA health advisory (screening, not a legal limit)Screening level, not a legal limit	Within the referenced health-based guidance value	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorohexanoic acid (PFHxA)	6 ng/L	400,000 ng/L Michigan EGLE state MCL (strictest US state)	Within a historical reference; current applicability unverified	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluoropentanoic acid (PFPeA)	5.3 ng/L	No federal or state limit; shown for transparency	Detected, no limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

24 other contaminants tested — none detected

Contaminant	Result	Benchmark	Status	Sampled	Source
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)	< 5 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)	< 5 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)	< 3 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)	< 5 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)	< 3 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)	< 2 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)	< 5 ng/L	10 ng/L federal MCL (2024)	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Lead (90th percentile)	Non-Detect (ND)	15 µg/L federal action level	Not detected above the reporting limit	2024–2026 monitoring period (still open)	Lead & Copper Rule 90th-percentile: CAL-WATER SERVICE CO.-CHICO (CA0410002)
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)	< 5 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)	< 6 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)	< 20 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)	< 3 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluoro-3-methoxypropanoic acid (PFMPA)	< 4 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluoro-4-methoxybutanoic acid (PFMBA)	< 3 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorobutanoic acid (PFBA)	< 5 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorodecanoic acid (PFDA)	< 3 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorododecanoic acid (PFDoA)	< 3 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluoroheptanesulfonic acid (PFHpS)	< 3 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluoroheptanoic acid (PFHpA)	< 3 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorononanoic acid (PFNA)	< 4 ng/L	10 ng/L federal MCL (2024)	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluoropentanesulfonic acid (PFPeS)	< 4 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorotetradecanoic acid (PFTA)	< 8 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluorotridecanoic acid (PFTrDA)	< 7 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
Perfluoroundecanoic acid (PFUnA)	< 2 ng/L	No federal or state limit; shown for transparency	Not detected above the reporting limit	2023-09-18 to 2024-07-23	UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorooctanesulfonic acid (PFOS)

Result: 22.5 ng/L
Benchmark: 4.0 ng/L federal MCL (2024)
Status: Above a historical reference; current applicability unverified
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorohexanesulfonic acid (PFHxS)

Result: 22.1 ng/L
Benchmark: 10 ng/L federal MCL (2024)
Status: Above a historical reference; current applicability unverified
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorooctanoic acid (PFOA)

Result: 6.8 ng/L
Benchmark: 4.0 ng/L federal MCL (2024)
Status: Above a historical reference; current applicability unverified
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Lithium

Result: 11.7 µg/L
Benchmark: 10 µg/L EPA health reference level (screening, not a legal limit)Screening level, not a legal limit
Status: Above the referenced health-based guidance value
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorobutanesulfonic acid (PFBS)

Result: 9.6 ng/L
Benchmark: 2,000 ng/L EPA health advisory (screening, not a legal limit)Screening level, not a legal limit
Status: Within the referenced health-based guidance value
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorohexanoic acid (PFHxA)

Result: 6 ng/L
Benchmark: 400,000 ng/L Michigan EGLE state MCL (strictest US state)
Status: Within a historical reference; current applicability unverified
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluoropentanoic acid (PFPeA)

Result: 5.3 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Detected, no limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

24 other contaminants tested — none detected

11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)

Result: < 5 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)

Result: < 5 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)

Result: < 3 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)

Result: < 5 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

4,8-Dioxa-3H-perfluorononanoic acid (ADONA)

Result: < 3 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)

Result: < 2 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)

Result: < 5 ng/L
Benchmark: 10 ng/L federal MCL (2024)
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Lead (90th percentile)

Result: Non-Detect (ND)
Benchmark: 15 µg/L federal action level
Status: Not detected above the reporting limit
Sampled: 2024–2026 monitoring period (still open)
Source: Lead & Copper Rule 90th-percentile: CAL-WATER SERVICE CO.-CHICO (CA0410002)

N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)

Result: < 5 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)

Result: < 6 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)

Result: < 20 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)

Result: < 3 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluoro-3-methoxypropanoic acid (PFMPA)

Result: < 4 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluoro-4-methoxybutanoic acid (PFMBA)

Result: < 3 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorobutanoic acid (PFBA)

Result: < 5 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorodecanoic acid (PFDA)

Result: < 3 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorododecanoic acid (PFDoA)

Result: < 3 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluoroheptanesulfonic acid (PFHpS)

Result: < 3 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluoroheptanoic acid (PFHpA)

Result: < 3 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorononanoic acid (PFNA)

Result: < 4 ng/L
Benchmark: 10 ng/L federal MCL (2024)
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluoropentanesulfonic acid (PFPeS)

Result: < 4 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorotetradecanoic acid (PFTA)

Result: < 8 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluorotridecanoic acid (PFTrDA)

Result: < 7 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Perfluoroundecanoic acid (PFUnA)

Result: < 2 ng/L
Benchmark: No federal or state limit; shown for transparency
Status: Not detected above the reporting limit
Sampled: 2023-09-18 to 2024-07-23
Source: UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)

Every value is the published result from the cited public record. A reporting limit is the lowest level the method could reliably quantify; a non-detect is not a guarantee of zero.

UCMR5 Analytical Results
UCMR5 Analytical Results: CAL-WATER SERVICE CO.-CHICO (CA0410002)
US EPA
Published
2026-01-15
Newest sample
2024-07-23
Findings here
30
View source ↗Source record
State SDWIS Compliance Record
Lead & Copper Rule 90th-percentile: CAL-WATER SERVICE CO.-CHICO (CA0410002)
US EPA SDWIS
Published
2026-07-09
Newest sample
2026
Findings here
1
View source ↗Source record

Methodology: how we analyze water.

Data & methodologyHow we analyze waterData integrity policy

Something off with your water's smell, color or taste?

Start with the hot-or-cold tap check. Where Cal-Water Service Co.-Chico reported something related, it's shown below.

Rotten-egg smell
Cloudy or milky water
Chlorine smell
Brown or yellow water
Metallic taste
Lead at Cal-Water Service Co.-Chico: not detected (90th percentile, 2024–2026 monitoring period (still open)). Lead has no taste, so a taste neither shows nor rules it out.

ZIP codes in Chico

A ZIP code is a postal area, not a water service area. Your water bill names your supplier.

CAL-WATER SERVICE CO.-CHICO serves Chico

Three PFAS above the 2024 federal limit

Perfluorooctanesulfonic acid

Perfluorohexanesulfonic acid

Perfluorooctanoic acid

Coverage by group

7 detected results, by distance from their limit

Test first, then treat what was found

Test your own tap

Watersafe Drinking Water Test Kit

ETR Labs Basic Water Quality Test Kit

Certified for a concern found here

Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200)

Aquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M)

Aquasana Clean Water Machine Countertop Filter (AQ-CWM2)

Patriot Pure Ultimate Water Filtration System

AquaTru Carafe Countertop Reverse-Osmosis Purifier (AT100)

AquaTru Classic Countertop Reverse-Osmosis Purifier (AT2000)

Waterdrop G3P600 Tankless Reverse-Osmosis System

Waterdrop G3P800 Tankless Reverse-Osmosis System

Whirlpool Filter 3 Refrigerator Water Filter (WHR3RXD1)

Frequently asked questions

Something off with your water's smell, color or taste?

ZIP codes in Chico