CheckPFAS

ZIP Code 90270

High Risk
High Risk PFAS Risk Level

PFAS above EPA limits detected

4 compounds exceed EPA Maximum Contaminant Levels in water serving this ZIP code. Standard pitcher filters like Brita do not remove PFAS. See filter recommendations below.

8
PFAS Detected
4
Above EPA Limits
3
Water Systems
660%
Highest % of MCL

Compounds Exceeding EPA Limits

PFOS Exceeds EPA limit
0 ppt MCL: 4 ppt 283% of limit
Detected: 11.30 ppt
PFOA Exceeds EPA limit
0 ppt MCL: 4 ppt 183% of limit
Detected: 7.30 ppt

What this means for you

One or more PFAS compounds were measured above the EPA's enforceable drinking water limit at a utility serving ZIP 90270. The EPA set these limits because long-term exposure at higher concentrations is associated with health effects including immune suppression, thyroid changes, and cancer risk increases. Standard pitcher filters (Brita, PUR) are not certified to remove PFAS. The most reliable at-home options are under-sink reverse osmosis systems or activated carbon block filters with an NSF/ANSI 58 certification specifically listing PFOA/PFOS reduction. Your water utility is required to bring levels into compliance by 2029 — filtering at the tap is the practical interim step if you'd like additional protection now.

MAYWOOD MUTUAL WATER CO. #1

CA1910084 High Risk
Water Type
Groundwater
PFAS Detected
2
Above MCL
1
State
California
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
11.30ppt
283% of limit
4 ppt⚠ Exceeds MCL
lithium
12600.00pptNo federal limitUnregulated

MAYWOOD MUTUAL WATER CO. #2

CA1910085 High Risk
Water Type
Groundwater
PFAS Detected
2
Above MCL
1
State
California
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
4.30ppt
108% of limit
4 ppt⚠ Exceeds MCL
lithium
14800.00pptNo federal limitUnregulated

MAYWOOD MUTUAL WATER CO. #3

CA1910086 High Risk
Water Type
Groundwater
PFAS Detected
4
Above MCL
2
State
California
Data Period
2023–2025

PFAS Test Results

CompoundDetectedvs. EPA LimitEPA LimitStatus
PFOS
Perfluorooctane sulfonic acid
26.40ppt
660% of limit
4 ppt⚠ Exceeds MCL
PFOA
Perfluorooctanoic acid
7.30ppt
183% of limit
4 ppt⚠ Exceeds MCL
PFHxS
Perfluorohexane sulfonic acid
6.10ppt
61% of limit
10 pptBelow limit
lithium
21800.00pptNo federal limitUnregulated
Note: ZIP code 90270 is served by 3 separate water utilities. Results above show data for each system independently.
About this data
Source
EPA UCMR 5 (Unregulated Contaminant Monitoring Rule, 5th cycle)
Data released
January 2026
Sampling period
January 2023 – December 2025
Systems tested
~10,000 public water systems serving > 25 people
Water systems (PWSID)
CA1910084, CA1910085, CA1910086
Detection threshold (MRL)
~1.5–2 ppt — "Not detected" means below this floor, not zero

Values shown are the highest single-sample concentration measured at entry points to the distribution system. Results reflect water quality at the treatment plant — aging pipes, building plumbing, and on-site storage can affect what actually reaches your tap.