Multnomah County, Oregon has about 795,897 residents (Census 2024 estimate) and 25 community water systems in EPA records. The largest local system is Portland Water Bureau, serving about 666,200 people from surface water.
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
Portland Water Bureau Measured (utility report, 2025) · High confidence
7–80 mg/L (varies by area; no single average published)
Source: PORTLAND WATER BUREAU water quality report, 2025
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
For a 3-person home using 57 gallons per person per day and regenerating weekly, you'd remove about 5,626 grains between regenerations. Suggested size: 24,000 grain. Hardness varies by area here, so this uses the harder plant's figure (4.7 gpg). If your address gets softer water, a smaller unit may do; check your area in the utility report or test your tap.
Estimate only. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
The 6 biggest of 25 community water systems on EPA records for this county. Service areas don't follow county lines; your water bill names your provider.
OR4100657 · serves about 666,200 people · Surface water
Lead 90th percentile: 5 ppb (period starting 2026-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
OR4100357 · serves about 73,932 people · Surface water
Lead 90th percentile: 3.8 ppb (period starting 2026-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
OR4100668 · serves about 65,443 people · Surface water
Lead 90th percentile: 3.4 ppb (period starting 2026-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
OR4100901 · serves about 16,185 people · Groundwater
Lead 90th percentile: 1.2 ppb (period starting 2024-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
OR4100296 · serves about 9,963 people · Groundwater
Lead 90th percentile: 6.9 ppb (period starting 2025-01-01). Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
OR4100904 · serves about 4,388 people · Groundwater
Lead 90th percentile: 1.4 ppb (period starting 2021-01-01) Older result. Action level: 15 ppb (drops to 10 ppb on Nov 1, 2027).
Public-record figures, not a test of your tap. Not 100% accurate or guaranteed. Confirm with a water test, your utility or a qualified pro before you buy or act.
A PFAS detection is not a violation. Federal limits (4 ppt for PFOA and PFOS) apply to running annual averages, with compliance required by 2029. In May 2026 EPA proposed extending the PFOA/PFOS deadline to 2031 and removing other PFAS limits; not final as of 2026-10-21.
These are public records for whole systems. Your home's pipes, fixtures and any private well can change what you drink. A certified lab test or a hardness test strip gives you your own numbers. Then use our PFAS and lead filter selector to see which certifications to look for.
1 of the 6 largest systems here have at least one health-based violation in EPA records since October 2021 (see each system below for status). Portland Water Bureau's most recent lead 90th percentile was 5 ppb (2026), below the 15 ppb action level. Public records can't guarantee what comes out of your tap, especially with older plumbing, so a home test is the surest check.
Portland Water Bureau reports hardness from 7 to 80 mg/L depending on where you live, with no single system-wide average, so check your area in its report or test your water. For a 3-person home at 4.7 gpg (the harder plant's figure, since your address may get either), our softener calculator suggests a 24,000 grain unit as a starting point.
None of the 6 sampled systems listed here detected PFAS above EPA's reporting levels in UCMR 5 testing.
Most homes are served by Portland Water Bureau or one of the other systems listed on this page, but service areas don't follow county lines. Your water bill names your provider, and its annual Consumer Confidence Report has the full test results.
Data as of October 21, 2026. Figures are copied from public records and combined with our own calculations; they can be out of date or wrong. Tapped Out isn't affiliated with any utility or the EPA. Written and reviewed by the Tapped Out team. How we calculate · All sources.