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CHEHALIS WATER DEPARTMENT

PWS ID: WA5312250 · Chehalis, Washington 98532

CHEHALIS WATER DEPARTMENT serves 11,426 people in Chehalis, Washington using Surface Water water sources. It has 42 recorded EPA violations, including 6 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: CHEHALIS WATER DEPARTMENT

CHEHALIS WATER DEPARTMENT is a local-owned community water system that delivers drinking water to 11,426 residents in Chehalis, Washington (Lewis County) through 3,853 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 42 total violations for this system , of which 6 (14%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 33 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.

The most frequently cited contaminant at this system is Surface Water Treatment Rule, recorded in 3 violations (TT, health-based). This system was sampled under EPA's UCMR5 PFAS monitoring program and no PFAS compounds were detected above the minimum reporting level.

Across Washington, EPA tracks 4,557 public water systems serving 9,736,844 people, with 314,648 cumulative violations and 20,590 health-based violations on record. About 92% of systems in the state carry at least one violation, and state-wide the average per system is 69 violations. CHEHALIS WATER DEPARTMENT's 42 violations sit below the Washington average. Statewide, 98 of 247 UCMR5-tested systems have reported PFAS detections (39.7%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
11,426
Total Violations
42
Health-Based Violations
6
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
3,853
County
Lewis
School/Daycare
No
MCL Violations
3
Monitoring Violations
33
Treatment Tech Violations
3

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Surface Water Treatment Rule TT 3 2005
Coliform (TCR) MCL 3 1992
Endrin MR 2 2006
Methoxychlor MR 2 2006
Toxaphene MR 2 2006
Hexachlorocyclopentadiene MR 2 2006
Atrazine MR 2 2006
Heptachlor MR 2 2006
Pentachlorophenol MR 2 2006
Chlordane MR 2 2006
BHC-GAMMA MR 2 2006
Di(2-ethylhexyl) adipate MR 2 2006
Simazine MR 2 2006
Di(2-ethylhexyl) phthalate MR 2 2006
LASSO MR 2 2006
Benzo(a)pyrene MR 2 2006
HEXACHLOROBENZENE MR 2 2006
Consumer Confidence Rule Other 2 2024
Heptachlor epoxide MR 2 2006
Gross Alpha, Excl. Radon and U MR 1 1979

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 30 samples detected PFAS.

Contaminant Date Result MRL Status
6:2 FTS 11/7/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFHpA 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFNA 11/7/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 11/7/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFOA 11/7/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFDA 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFUnA 11/7/2024 <0.002 µg/L 0.002 µg/L Not Detected
11Cl-PF3OUdS 11/7/2024 <0.005 µg/L 0.005 µg/L Not Detected
9Cl-PF3ONS 11/7/2024 <0.002 µg/L 0.002 µg/L Not Detected
ADONA 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFBS 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
NMeFOSAA 11/7/2024 <0.006 µg/L 0.006 µg/L Not Detected
NEtFOSAA 11/7/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 11/7/2024 <0.007 µg/L 0.007 µg/L Not Detected
PFTA 11/7/2024 <0.008 µg/L 0.008 µg/L Not Detected
PFHpS 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 11/7/2024 <0.005 µg/L 0.005 µg/L Not Detected
NFDHA 11/7/2024 <0.02 µg/L 0.02 µg/L Not Detected
PFBA 11/7/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFMBA 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 11/7/2024 <0.004 µg/L 0.004 µg/L Not Detected
8:2 FTS 11/7/2024 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 11/7/2024 <0.003 µg/L 0.003 µg/L Not Detected
lithium 11/7/2024 <9 µg/L 9 µg/L Not Detected
PFPeS 11/7/2024 <0.004 µg/L 0.004 µg/L Not Detected

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records — or to file a complaint, request a Consumer Confidence Report, or check current monitoring status — go directly to the federal and state regulators that enforce the Safe Drinking Water Act for CHEHALIS WATER DEPARTMENT.

Federal Source of Truth

EPA SDWIS — Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID WA5312250 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Washington Drinking Water Authority

Washington State Department of Health — Office of Drinking Water is the primacy agency that licenses and inspects CHEHALIS WATER DEPARTMENT under EPA-delegated authority.

Open WA regulator portal

Source: Washington State Department of Health — Office of Drinking Water

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2024 Consumer Confidence Rule Other 2 SDWIS / WA5312250 / 7000
2006 Endrin MR 2 SDWIS / WA5312250 / 2005
2006 Methoxychlor MR 2 SDWIS / WA5312250 / 2015
2006 Toxaphene MR 2 SDWIS / WA5312250 / 2020
2006 Hexachlorocyclopentadiene MR 2 SDWIS / WA5312250 / 2042
2006 Atrazine MR 2 SDWIS / WA5312250 / 2050
2006 Heptachlor MR 2 SDWIS / WA5312250 / 2065
2006 Pentachlorophenol MR 2 SDWIS / WA5312250 / 2326
2006 Chlordane MR 2 SDWIS / WA5312250 / 2959
2006 BHC-GAMMA MR 2 SDWIS / WA5312250 / 2010
2006 Di(2-ethylhexyl) adipate MR 2 SDWIS / WA5312250 / 2035
2006 Simazine MR 2 SDWIS / WA5312250 / 2037
2006 Di(2-ethylhexyl) phthalate MR 2 SDWIS / WA5312250 / 2039
2006 LASSO MR 2 SDWIS / WA5312250 / 2051
2006 Benzo(a)pyrene MR 2 SDWIS / WA5312250 / 2306

How CHEHALIS WATER DEPARTMENT Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric CHEHALIS WATER DEPARTMENT Washington avg Federal benchmark
Total violations 42 69 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 6 4.5 Indicates a contaminant exceeded a federal MCL
PFAS detection None 39.7% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 11,426 2,137 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 4,557 regulated public water systems in Washington.

Federal MCL reference — Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is CHEHALIS WATER DEPARTMENT water safe to drink? ▼
CHEHALIS WATER DEPARTMENT (PWS ID: WA5312250) has 42 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 11,426 people using Surface Water sources.
How many people does CHEHALIS WATER DEPARTMENT serve? ▼
CHEHALIS WATER DEPARTMENT serves 11,426 people in Chehalis, Washington. It is a Local-owned system using Surface Water water sources with 3,853 service connections.
What type of violations does CHEHALIS WATER DEPARTMENT have? ▼
CHEHALIS WATER DEPARTMENT has 42 total violations: 6 health-based violations (MCL exceedances or treatment failures), 33 monitoring/reporting violations, and 3 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in CHEHALIS WATER DEPARTMENT water? ▼
No. CHEHALIS WATER DEPARTMENT was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.
What water source does CHEHALIS WATER DEPARTMENT use? ▼
CHEHALIS WATER DEPARTMENT uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by Kiznis Studio Editorial