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Big Oak Marina

What EPA’s and CDC’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves
30 people
Connections
25
Water source
Groundwater
Based in
Portland, OR
County
Multnomah
Owner
Private
The ZIP code it serves

97231

The short answer

1 result is above the health goal. The worst: Lead, above the health goal. 2 health-based violations since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2023 to 2024.

Nitrate, arsenic and uranium: Oregon’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2022 to 2023.

Above the health goal1

Lead

Comes from pipes, often your own

Above the health goal

10ppb

90th percentile, 2024

In the latest period, 9 in 10 homes sampled were at or below 10 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027, and this result is at or above that. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits1

Nitrate

Comes from the source

Below EPA’s limits

0.07ppm

Highest yearly average, 2022 to 2023

Averaged by year, the highest was 0.07 ppm, in 2023, below EPA’s legal limit of 10 ppm. That was also the latest year on file.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Uranium

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. How whole-house systems compare.

Filters with those claims on a certifier’s listing

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Compare five-year costs

The best water filters for lead, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Revised Total Coliform RuleE. coli was confirmed in the water system.EPA: Maximum Contaminant Level Violation, E. coli (RTCR)Sept. 1, 2024 to Sept. 30, 2024—Resolved
Revised Total Coliform RuleE. coli was confirmed in the water system.EPA: Maximum Contaminant Level Violation, E. coli (RTCR)Aug. 1, 2024 to Aug. 31, 2024—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 80 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Nitrate, arsenic and uranium results here are Oregon’s yearly averages as CDC publishes them, from 2022 on, with EPA’s national file for 2012 to 2019. Big Oak Marina’s own annual report, which it must send you every year, has the contaminants this page does not show.

  • Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.

  • What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.

  • Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; CDC’s yearly averages for Oregon cover 2022 to 2023.

Testing your own tap

Big Oak Marina’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Oregon certifies.

The 3 labs Oregon certifies closest to the area Big Oak Marina serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • BSK Associates ?Vancouver

    Vancouver, WA · about 10 miles

    Certified for bacteria, nitrate, minerals and other inorganics

    (360) 869-6344

  • OMIC USA Inc.

    Portland, OR · about 11 miles

    (503) 223-1497

  • Alexin Analytical Laboratories, Inc.

    Tigard, OR · about 17 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts

    (503) 639-9311

Oregon State University Extension Well Water Program: Nitrate screening of well water at many of its groundwater education events. The screening is free. Water Testing Guidance for Private Wells, OSU Well Water Program.

All 91 certified labs for Oregon

Sources

PWSID OR4106054. Rebuilt from EPA data on Oct. 18, 2026.

Also in Multnomah County

All Oregon utilities

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