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WaterSafeCheck
Official EPA SDWIS Verified ReportWater Quality & Testing GuideStatus: Active Advisories Noted

ZIP Code 97035 Water Quality & Testing Report

Lake Oswego, OR · Clackamas County County · Updated for 2026

Quick EPA Verified Answer

Is Tap Water Safe to Drink in ZIP 97035 (Lake Oswego, OR)?

Yes, tap water in ZIP code 97035 (Lake Oswego, OR) is safe to drink under EPA Safe Drinking Water Act standards. Supplied by Lake Oswego Municipal Water, the area earns an EPA Safety Grade of A (88/100) with 0 health violations, 1.5 ppb lead, and soft (48 mg/L / 2.8 GPG) water.

Safety Score
A

Water Safety Grade

Excellent — Meets all EPA standards

Health Violations

0

Total Violations

5

Lead Risk

Moderate

Contaminants

0

About Tap Water in ZIP Code 97035

Tap water in ZIP code 97035 (Lake Oswego, OR) is distributed by Lake Oswego Municipal Water (EPA ID: OR4100457), serving approximately 40,000 residents. Based on EPA Safe Drinking Water Act compliance records, this system receives a water safety grade of A with a composite quality score of 88/100.

Water System

Lake Oswego Municipal Water

EPA ID: OR4100457

Water Source

Surface Water

Population Served

40,000 residents

County

Clackamas County County, Oregon

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Lead Levels in ZIP 97035

EPA action level: 15 ppb | Public health goal: 0 ppb

Lead Level: 1.5 ppb — Very Low

The 90th percentile lead level in 97035 is 1.5 ppb. This meets the EPA action level of 15 ppb. Health experts recommend a target of 0 ppb for optimal safety.

Lead exposure risk in 97035 is rated Moderate. EPA models estimate a 39% exposure probability based on housing and infrastructure age.

Lead Level (90th percentile)
1.50 ppb (0.0015 mg/L)
Lead Exposure Risk Rating
Moderate
Lead Exposure Probability

EPA model estimate based on housing age and infrastructure

39%
Note: Lead levels above are the 90th percentile from EPA monitoring — meaning 90% of samples were at or below this level. Even "undetected" tap water lead doesn't account for lead leaching from home plumbing. If your home was built before 1986, individual tap testing is recommended.
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Water Hardness & Mineral Content

Grains per gallon (GPG) & Parts per million (PPM / mg/L)

Classification: Soft2.8 GPG · 48 mg/L

Water in ZIP 97035 is classified as Soft (48 mg/L / 2.8 GPG). Soft water produces abundant soap lather, prevents scale buildup in water heaters, and does not leave spots on dishes.

Recommendation: No water softener is needed. Standard carbon filtration is sufficient for taste and chlorine reduction.
Hardness (GPG)

Grains per gallon

2.8 GPG
Hardness (PPM / mg/L)

Parts per million CaCO3

48 mg/L
Appliance Scaling Risk
Very Low

Official EPA SDWIS Database Entry

Utility: Lake Oswego Municipal Water · PWSID: OR4100457

Verify on EPA.gov
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Violation History

Past 5 years — EPA SDWIS data

Lake Oswego Municipal Water has recorded 5 violations, but none are health-based (e.g., administrative or monitoring infractions). Additionally, 1 boil water advisory/advisories were active during this period.

Total Violations (5 yr)
5
Health-Based Violations
0
Unresolved Violations
0
Boil Water Advisories
1
Compliance Risk
Moderate

Regulatory compliance risk for this utility is rated Moderate based on past reporting and enforcement records.

⚗️

Contaminants Detected

Contaminants with health-based violations on record

No health-based contaminant violations are on record for ZIP code 97035 under the Safe Drinking Water Act.

⚖ Enforcement Actions

EPA or state regulators have issued 10 enforcement actions to address compliance lapses.
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Water Source & Environmental Factors

Surface Water

This system draws water from lakes, rivers, or reservoirs. Surface water is treated to remove sediment, microorganisms, and chemical contaminants before reaching taps.

Water Source Type
Surface Water
EPA Radon Zone

Lower potential

Zone 3
Annual Flood Risk Cost

Estimated annual flood-related costs per property

$2
Energy Burden

% of household income spent on energy — indicator of older infrastructure

1.1%

EPA Radon Zone 3 — lower radon potential, though the EPA still recommends testing all homes.

Water Quality Testing in ZIP 97035

Tap Water & Well Testing Recommendations

Residents in ZIP code 97035 served by Lake Oswego Municipal Water can test tap water or private well systems to verify water purity. Testing detects hidden contaminants before they impact family health.

Tap Water Testing Steps

  • 1.Conduct a certified lead check if your home was constructed before 1986.
  • 2.Use certified lab testing kits rather than uncalibrated test strips for regulated compliance.
  • 3.Sample water from both your kitchen faucet and water heater to compare line purity.

Private Well Testing Steps

  • •Test for Coliform bacteria and Nitrates annually.
  • •Test for heavy metals, radon, and PFAS every 3 years.
  • •Send samples to a state-certified drinking water laboratory recognized by Oregon Health Authority.
Certified Lab Testing: Always use an EPA-certified drinking water laboratory in OR for formal legal or real estate compliance testing.

🛡 What Should You Do? — ZIP 97035 Recommendations

  • ✓ Run cold water for 30 seconds each morning before use — especially if pipes are old
  • ✓ Request your annual Consumer Confidence Report from Lake Oswego Municipal Water
  • ✓ If your home was built before 1986, consider testing your own tap for lead
  • ✓ Use a pitcher filter (NSF/ANSI 42 certified) for improved taste

Recommended Taste & Safety Filter:

🚰

NSF/ANSI 53 Certified Pitcher Filter

Best for removing aesthetic chlorine, odors, and low-level heavy metals.

Filter Selection Guide →

Frequently Asked Questions — ZIP 97035 Water Quality

Is tap water safe to drink in ZIP code 97035?+
Yes — tap water in 97035 (Lake Oswego, OR) meets EPA standards with a water safety grade of A. No health-based violations are on record in the past 5 years.
How do I get my water tested in ZIP 97035 (Lake Oswego, OR)?+
To test water quality in ZIP 97035, you can order a certified drinking water test kit or send water samples to an EPA/NELAP certified laboratory in OR. Certified testing checks for lead, coliform bacteria, nitrates, hardness, and PFAS that standard test strips miss. Contact Oregon Health Authority for a list of certified regional labs.
How hard is the tap water in 97035?+
Tap water in 97035 is classified as Soft with an estimated mineral hardness of 48 mg/L (2.8 GPG). No water softener is needed. Standard carbon filtration is sufficient for taste and chlorine reduction.
Should I test private well water in 97035?+
Yes. Unlike municipal systems, private wells in 97035 are not regulated by the EPA or local utilities. Private well owners should test their water annually for coliform bacteria and nitrates, and every 3 to 5 years for heavy metals (lead, arsenic) and volatile organic compounds.
What is the lead level in 97035 tap water?+
The 90th percentile lead level in 97035 is 1.5 ppb. The EPA action level is 15 ppb. This is below the EPA action level.
Is there an active boil water notice in 97035?+
EPA historical records indicate 1 boil water event(s) occurred within this system. Always check with your local water provider (Lake Oswego Municipal Water) for real-time emergency advisories.
Who provides tap water to 97035?+
Tap water in ZIP code 97035 is provided by Lake Oswego Municipal Water (EPA ID: OR4100457), serving approximately 40,000 residents.
What water filter should I use in 97035?+
Based on water metrics for 97035, we recommend None / Standard Pitcher. Look for certifications such as NSF/ANSI 42 (Chlorine, Taste & Odor).

Data Sources & Methodology

Water quality data for ZIP code 97035 is compiled from the EPA Safe Drinking Water Information System (SDWIS), EPA ECHO enforcement database, UCMR5 unregulated contaminant monitoring, and Consumer Confidence Reports filed by Lake Oswego Municipal Water. Safety scores are composite metrics derived from violation history, lead levels, enforcement actions, and infrastructure risk indicators. Data reflects a 5-year monitoring window. Last dataset update: 2024. View EPA source data →