County water report

Multnomah County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Multnomah County, Oregon.

Water grade

Water score

66.8

State rank

of 36

Health violations

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

107

28,680 recent measurements

Live streamflow

54%

WILLAMETTE RIVER AT PORTLAND, OR

Water at a glance

Key Water Indicators for Multnomah County

EPA SDWIS

Safety Grade

Score: 66.8 / 100

EPA SDWIS

Active Violations

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

54% of mean

WILLAMETTE RIVER AT PORTLAND, OR

EPA WQP

Monitoring Sites

107

28,680 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

66.8/100

Health violations

Health-based violations

Violations per 100K served

2.5

Population-normalized SDWIS rate

Data center water stress

Multnomah County has 4 facilities in the DCWSI dataset.

ByCounty's DCWSI ranks this county #88 nationally by combining its water score with mapped data center density.

DCWSI

67.2

0-100 index

Facility count

67.8 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

+16.8

Compared with US county median

Named operators

Digital Fortress, IncH5 Data CentersAlco Properties

Mapped facilities

Digital Fortress - Portland 1
Portland · Digital Fortress, Inc
OSM
H5 DC - Portland
Portland · H5 Data Centers
OSM
Pittock Block
Portland
OSM
The Pittock Internet Exchange
Portland · Alco Properties
OSM

See the Multnomah County data-center report Review methodology

Data Center Water Budget Calculator

Estimate daily water use for a hypothetical facility in Multnomah County.

Facility size: 100 MW

1 MW1,000 MW

Cooling type

Utilization: 70%

40%100%

799K gallons/dayHigh Impact

Your facility would use 21.0% of this county's industrial water baseline. Verify water rights and long-term drought projections before committing.

21.0% of county industrial baseline3.01 Mgal/day remaining headroom

Based on USGS 2020 water-use data and EPA-standard cooling intensity constants. Not a substitute for site-specific water rights analysis.

Editorial analysis

Understanding Multnomah County’s Water

Drinking Water Quality Overview

EPA SDWIS

Multnomah County earns a B grade for drinking water quality, scoring 66.8 out of 100. Over the past five years, EPA SDWIS records 21 health-based violations — a pattern that public water utilities are required to disclose and correct.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T11:45:00.000-07:00) puts WILLAMETTE RIVER at 17.5k cfs — well below its long-term average at 54% of mean — low-flow conditions worth noting for water-dependent ecosystems. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Multnomah County has extensive coverage with 107 active monitoring sites with 28,680 recent measurements on record. Predominant monitoring categories include organics, pesticide and physical. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for Multnomah County

Water Verdict

Multnomah County receives a fair water quality assessment with a grade of B and a score of 66.8 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring.

Violation Context

Multnomah County has recorded 21 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 2.5 violations per 100,000 people served, this rate is relatively low compared to many U.S. counties.

Consumer Guidance

Tap water in Multnomah County meets baseline safety standards, though the compliance record shows some violations worth watching. Multnomah County's drinking-water compliance score is 66.8 out of 100. The violation rate for Multnomah County is 2.5 per 100,000 people served. Running tap water for 30 seconds before drinking can reduce any localized lead exposure from household plumbing. Requesting your utility's most recent Consumer Confidence Report is the fastest way to identify which specific contaminants were flagged. With 107 active water-quality monitoring sites in Multnomah County, data coverage is strong. A pipeline streamflow snapshot from the WILLAMETTE RIVER gauge is also available on this page.

Regional Context

Multnomah County has better water quality than the average county in Oregon. Its water score is 22.2 points higher than the state average, indicating stronger water system performance relative to neighboring counties.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in Multnomah County's water environment

Official EPA Resources for Multnomah County

EPA How's My Waterway

Interactive watershed health data for Multnomah County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Multnomah County

Consumer Confidence Reports (OR)

Annual water quality reports from utilities in Oregon

Past 5 years

Water Quality Monitoring

Monitoring Sites

107

Active in the past 5 years

Measurements Recorded

29K

28,680 total readings

Most Measured

Organics, Pesticide
Physical
Organics, Other

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

17.5Kcfs

May 14, 6:45 PM UTC

vs Long-Term Average

54%

Well below typical

Primary Streamgage

WILLAMETTE RIVER AT PORTLAND, OR

USGS site: 14211720
Drainage area: 11,200 sq mi
Long-term mean: 32.5K cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

Free tool

Estimate Your Water Costs

Water Cost Estimate

Household size

3 people · ~225 gal/day

Filter type

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Multnomah County:C — Moderate

Some violations or watershed impairment detected.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

Try the full calculator →

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Frequently Asked Questions

What is the water quality in Multnomah County, Oregon?

Multnomah County, Oregon has a drinking-water quality grade of B with a score of 66.8/100, based on EPA SDWIS compliance data. The county has 21 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.

Are there any water violations in Multnomah County?

Multnomah County has 21 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.

How much water-quality monitoring happens in Multnomah County?

EPA's Water Quality Portal records 28,680 measurements from 107 monitoring sites in Multnomah County over the past five years. The most frequently measured characteristic groups are Organics, Pesticide, Physical, Organics, Other. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.

What's happening with rivers in Multnomah County right now?

Multnomah County's primary USGS streamgage on the WILLAMETTE RIVER has a pipeline snapshot of 17,500 cubic feet per second — 54% of the long-term mean of 32,501.13 cfs. This is well below typical — often a signal of drought stress on source water. For the latest gauge feed, visit waterdata.usgs.gov.

How does Multnomah County water compare to the Oregon average?

Multnomah County's SDWIS water quality score of 66.8/100 is higher than the Oregon state average of 44.6. The average water quality grade across Oregon is D, based on data from 36 counties with available SDWIS data.

Is tap water safe to drink in Multnomah County?

Based on EPA SDWIS data, Multnomah County has a water quality grade of B (66.8/100). This indicates good to excellent water quality with strong SDWIS compliance. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).

Why does Multnomah County have so many water violations?

Multnomah County has 21 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.

How does Multnomah County rank for water quality in Oregon?

Multnomah County ranks #9 out of 36 counties in Oregon by SDWIS water quality score (1 = best). With a score of 66.8/100, it falls in the top third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Washington County

Oregon

67.7

Water score

Deschutes County

Oregon

60.1

Water score

Linn County

Oregon

53.8

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

By Evan Brooks, Data EditorUpdated May 14, 2026Reviewed by Evan Brooks, Data Editor

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