HERMISTON, CITY OF

Q: Is HERMISTON, CITY OF water safe to drink?

HERMISTON, CITY OF (PWS ID: OR4100372) has 168 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 6 PFAS compounds found. This system serves 20,000 people using Surface Water sources.

Q: What type of violations does HERMISTON, CITY OF have?

HERMISTON, CITY OF has 168 total violations: 9 health-based violations (MCL exceedances or treatment failures), 157 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.

Q: Has PFAS been detected in HERMISTON, CITY OF water?

Yes. UCMR5 testing detected 6 PFAS compounds in HERMISTON, CITY OF's water supply: lithium, PFBS, PFHxS, PFOS, PFPeA, and others. PFAS are persistent "forever chemicals" that do not break down in the environment.

Q: What water source does HERMISTON, CITY OF use?

HERMISTON, CITY OF uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.

Q: 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.

Reviewed byPlainWater Editorial, Drinking Water Quality Editorial Team · June 4, 2026

PWS ID: OR4100372 · HERMISTON, Oregon 97838

HERMISTON, CITY OF serves 20,000 people in HERMISTON, Oregon using Surface Water water sources. It has 168 recorded EPA violations, including 9 health-based violations. PFAS "forever chemicals" were detected in UCMR5 testing (6 compounds found).

Water Quality Snapshot: HERMISTON, CITY OF

HERMISTON, CITY OF is a local-owned community water system that delivers drinking water to 20,000 residents in HERMISTON, Oregon (Umatilla County) through 5,979 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 168 total violations for this system , of which 9 (5%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 157 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 10 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 6 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 32 ppt. PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across Oregon, EPA tracks 2,518 public water systems serving 4,005,242 people, with 206,659 cumulative violations and 20,339 health-based violations on record. About 99% of systems in the state carry at least one violation, and state-wide the average per system is 82.1 violations. HERMISTON, CITY OF's 168 violations sit above the Oregon average. Statewide, 30 of 125 UCMR5-tested systems have reported PFAS detections (24%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

6 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served

20,000

Total Violations

168

Health-Based Violations

Water Source

Surface Water

System Details

System Type: Community
Owner Type: Local
Connections: 5,979
County: Umatilla
School/Daycare: No
MCL Violations: 7
Monitoring Violations: 157
Treatment Tech Violations: 2

Violation History

Contaminant violations recorded by EPA.

Contaminant	Category	Count	Latest
Coliform (TCR)	MR	10	1993
TTHM	MR	10	2016
Total Haloacetic Acids (HAA5)	MR	10	2016
Surface Water Treatment Rule	MR	9	2013
Coliform (TCR)	MCL	7	1998
COLIPHAGE	MR	6	2022
Interim Enhanced Surface Water Treatment Rule	MR	5	2013
Arsenic	MR	3	2009
Endrin	MR	2	2002
BHC-GAMMA	MR	2	2002
Toxaphene	MR	2	2002
Dalapon	MR	2	2002
Diquat	MR	2	2002
Endothall	MR	2	2002
Glyphosate	MR	2	2002
Di(2-ethylhexyl) adipate	MR	2	2002
OXAMYL	MR	2	2002
Simazine	MR	2	2002
Picloram	MR	2	2002
Dinoseb	MR	2	2002
Hexachlorocyclopentadiene	MR	2	2002
Atrazine	MR	2	2002
LASSO	MR	2	2002
Heptachlor	MR	2	2002
Heptachlor epoxide	MR	2	2002
2,4,5-TP	MR	2	2002
HEXACHLOROBENZENE	MR	2	2002
Total Polychlorinated Biphenyls (PCB)	MR	2	2002
1,2-DIBROMO-3-CHLOROPROPANE	MR	2	2002
ETHYLENE DIBROMIDE	MR	2	2002

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 22 of 327 samples detected PFAS.

Contaminant	Date	Result	MRL	Status
PFTA	9/11/2023	<0.008 µg/L	0.008 µg/L	Not Detected
lithium	9/11/2023	<9 µg/L	9 µg/L	Not Detected
NMeFOSAA	9/11/2023	<0.006 µg/L	0.006 µg/L	Not Detected
NEtFOSAA	9/11/2023	<0.005 µg/L	0.005 µg/L	Not Detected
PFTrDA	9/11/2023	<0.007 µg/L	0.007 µg/L	Not Detected
PFTA	6/20/2023	<0.008 µg/L	0.008 µg/L	Not Detected
PFTrDA	6/20/2023	<0.007 µg/L	0.007 µg/L	Not Detected
NEtFOSAA	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
NMeFOSAA	6/20/2023	<0.006 µg/L	0.006 µg/L	Not Detected
lithium	6/20/2023	29.0000 µg/L	9 µg/L	Detected
PFPeS	6/20/2023	<0.004 µg/L	0.004 µg/L	Not Detected
PFPeA	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
4:2 FTS	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
PFHpS	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
PFMBA	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
PFDA	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
PFMPA	6/20/2023	<0.004 µg/L	0.004 µg/L	Not Detected
8:2 FTS	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
NFDHA	6/20/2023	<0.02 µg/L	0.02 µg/L	Not Detected
PFBS	6/20/2023	0.0034 µg/L	0.003 µg/L	Detected
PFEESA	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
6:2 FTS	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
PFDoA	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
PFTA	6/20/2023	<0.008 µg/L	0.008 µg/L	Not Detected
PFTrDA	6/20/2023	<0.007 µg/L	0.007 µg/L	Not Detected
NEtFOSAA	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
lithium	6/20/2023	32.0000 µg/L	9 µg/L	Detected
PFHpA	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
PFHxS	6/20/2023	0.0080 µg/L	0.003 µg/L	Detected
9Cl-PF3ONS	6/20/2023	<0.002 µg/L	0.002 µg/L	Not Detected
PFBA	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
HFPO-DA	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
NMeFOSAA	6/20/2023	<0.006 µg/L	0.006 µg/L	Not Detected
ADONA	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
PFNA	6/20/2023	<0.004 µg/L	0.004 µg/L	Not Detected
11Cl-PF3OUdS	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
PFUnA	6/20/2023	<0.002 µg/L	0.002 µg/L	Not Detected
PFHxA	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
PFOA	6/20/2023	<0.004 µg/L	0.004 µg/L	Not Detected
PFOS	6/20/2023	0.0060 µg/L	0.004 µg/L	Detected
8:2 FTS	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
NEtFOSAA	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
NMeFOSAA	6/20/2023	<0.006 µg/L	0.006 µg/L	Not Detected
lithium	6/20/2023	<9 µg/L	9 µg/L	Not Detected
PFBS	6/20/2023	0.0100 µg/L	0.003 µg/L	Detected
PFHpA	6/20/2023	<0.003 µg/L	0.003 µg/L	Not Detected
PFHxS	6/20/2023	0.0084 µg/L	0.003 µg/L	Detected
11Cl-PF3OUdS	6/20/2023	<0.005 µg/L	0.005 µg/L	Not Detected
PFNA	6/20/2023	<0.004 µg/L	0.004 µg/L	Not Detected
PFOS	6/20/2023	0.0078 µg/L	0.004 µg/L	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 HERMISTON, CITY OF.

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 OR4100372 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Oregon Drinking Water Authority

Oregon's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find OR regulator via EPA SDWIS

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
2025	Revised Total Coliform Rule	MON	1	SDWIS / OR4100372 / 8000
2023	Nitrate	MR	1	SDWIS / OR4100372 / 1040
2022	COLIPHAGE	MR	6	SDWIS / OR4100372 / 3028
2016	TTHM	MR	10	SDWIS / OR4100372 / 2950
2016	Total Haloacetic Acids (HAA5)	MR	10	SDWIS / OR4100372 / 2456
2013	Surface Water Treatment Rule	MR	9	SDWIS / OR4100372 / 0200
2013	Interim Enhanced Surface Water Treatment Rule	MR	5	SDWIS / OR4100372 / 0300
2009	Arsenic	MR	3	SDWIS / OR4100372 / 1005
2009	Xylenes, Total	MR	2	SDWIS / OR4100372 / 2955
2009	o-Dichlorobenzene	MR	2	SDWIS / OR4100372 / 2968
2009	p-Dichlorobenzene	MR	2	SDWIS / OR4100372 / 2969
2009	1,1-Dichloroethylene	MR	2	SDWIS / OR4100372 / 2977
2009	trans-1,2-Dichloroethylene	MR	2	SDWIS / OR4100372 / 2979
2009	1,1,1-Trichloroethane	MR	2	SDWIS / OR4100372 / 2981
2009	Carbon tetrachloride	MR	2	SDWIS / OR4100372 / 2982

How HERMISTON, CITY OF Compares

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

Metric	HERMISTON, CITY OF	Oregon avg	Federal benchmark
Total violations	168	82.1	SDWA compliance — any non-zero count is a recorded breach
Health-based violations	9	8.1	Indicates a contaminant exceeded a federal MCL
PFAS detection	6 compounds	24%	EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served	20,000	1,591	Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,518 regulated public water systems in Oregon.

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 HERMISTON, CITY OF water safe to drink? ▼

HERMISTON, CITY OF (PWS ID: OR4100372) has 168 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 6 PFAS compounds found. This system serves 20,000 people using Surface Water sources.

How many people does HERMISTON, CITY OF serve? ▼

HERMISTON, CITY OF serves 20,000 people in HERMISTON, Oregon. It is a Local-owned system using Surface Water water sources with 5,979 service connections.

What type of violations does HERMISTON, CITY OF have? ▼

HERMISTON, CITY OF has 168 total violations: 9 health-based violations (MCL exceedances or treatment failures), 157 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.

Has PFAS been detected in HERMISTON, CITY OF water? ▼

Yes. UCMR5 testing detected 6 PFAS compounds in HERMISTON, CITY OF's water supply: lithium, PFBS, PFHxS, PFOS, PFPeA, and others. PFAS are persistent "forever chemicals" that do not break down in the environment.

What water source does HERMISTON, CITY OF use? ▼

HERMISTON, CITY OF 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.

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