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WEST SLOPE WATER DISTRICT

PWS ID: OR4100660 · PORTLAND, Oregon 97298

WEST SLOPE WATER DISTRICT serves 11,000 people in PORTLAND, Oregon using Surface Water water sources. It has 32 recorded EPA violations, including 11 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: WEST SLOPE WATER DISTRICT

WEST SLOPE WATER DISTRICT is a local-owned community water system that delivers drinking water to 11,000 residents in PORTLAND, Oregon (Washington County) through 3,234 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 32 total violations for this system , of which 11 (34%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 16 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 13 violations (MR). This system was sampled under EPA's UCMR5 PFAS monitoring program and no PFAS compounds were detected above the minimum reporting level.

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. WEST SLOPE WATER DISTRICT's 32 violations sit below 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.

Population Served
11,000
Total Violations
32
Health-Based Violations
11
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
3,234
County
Washington
School/Daycare
No
MCL Violations
10
Monitoring Violations
16
Treatment Tech Violations
1

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 13 2013
Coliform (TCR) MCL 10 2011
Revised Total Coliform Rule MON 3 2018
Lead and Copper Rule TT 1 2018
Consumer Confidence Rule Other 1 2023

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 120 samples detected PFAS.

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

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 OR4100660 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
2023 Consumer Confidence Rule Other 1 SDWIS / OR4100660 / 7000
2018 Revised Total Coliform Rule MON 3 SDWIS / OR4100660 / 8000
2018 Lead and Copper Rule TT 1 SDWIS / OR4100660 / 5000
2013 Coliform (TCR) MR 13 SDWIS / OR4100660 / 3100
2011 Coliform (TCR) MCL 10 SDWIS / OR4100660 / 3100

How WEST SLOPE WATER DISTRICT Compares

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

Metric WEST SLOPE WATER DISTRICT Oregon avg Federal benchmark
Total violations 32 82.1 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 11 8.1 Indicates a contaminant exceeded a federal MCL
PFAS detection None 24% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 11,000 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 WEST SLOPE WATER DISTRICT water safe to drink? ▼
WEST SLOPE WATER DISTRICT (PWS ID: OR4100660) has 32 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 11,000 people using Surface Water sources.
How many people does WEST SLOPE WATER DISTRICT serve? ▼
WEST SLOPE WATER DISTRICT serves 11,000 people in PORTLAND, Oregon. It is a Local-owned system using Surface Water water sources with 3,234 service connections.
What type of violations does WEST SLOPE WATER DISTRICT have? ▼
WEST SLOPE WATER DISTRICT has 32 total violations: 11 health-based violations (MCL exceedances or treatment failures), 16 monitoring/reporting violations, and 1 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in WEST SLOPE WATER DISTRICT water? ▼
No. WEST SLOPE WATER DISTRICT was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.
What water source does WEST SLOPE WATER DISTRICT use? ▼
WEST SLOPE WATER DISTRICT 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 PlainWater Editorial