Knappa Water Association
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
- 1,800 people
- Connections
- 605
- Water source
- Groundwater
- Based in
- Astoria, OR
- County
- Clatsop
- Owner
- Private
The ZIP code it serves
The short answer
Nothing in EPA’s and CDC’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.
What was found
Nitrate, arsenic, haloacetic acids (HAA5) and total trihalomethanes (TTHM): Oregon’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2023, with EPA’s 2012 to 2019 file for earlier years.
Uranium: EPA’s compliance monitoring file, samples taken from Aug. 9, 2017 to Aug. 23, 2017. Newer results are in the utility’s annual water quality report.
Below EPA’s limits1
Nitrate
Comes from the source
0.6ppm
Highest yearly average, 2020 to 2023
2023 average: 0.24 ppm
Averaged by year, the highest was 0.6 ppm, in 2022, below EPA’s legal limit of 10 ppm. In 2023, the latest year on file, it averaged 0.24 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.9 ppm, in 2013.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
5 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Haloacetic acids (HAA5)
- Lead
- Total trihalomethanes (TTHM)
- Uranium
Violations since 2016
No health-based violations on file with EPA since 2016. There are 6 monitoring or reporting violations: a sample missed, late or not reported.
What this report can’t tell you
Everything else. Nitrate, arsenic, haloacetic acids (HAA5) and total trihalomethanes (TTHM) results here are Oregon’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Uranium comes from EPA’s file alone, which ends in 2019. Knappa Water Association’s own annual report, which it must send you every year, has newer results for those and 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 2020 to 2023; EPA’s compliance samples are from Aug. 9, 2017 to Aug. 23, 2017.
Testing your own tap
The 3 labs Oregon certifies closest to the area Knappa Water Association serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Camp Rilea Laboratory
Warrenton, OR · about 11 miles
Certified for bacteria, nitrate
ALS Environmental, Kelso
Kelso, WA · about 45 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, PFAS
BSK Associates ?Vancouver
Vancouver, WA · about 62 miles
Certified for bacteria, nitrate, minerals and other inorganics
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 OregonSources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- CDC Environmental Public Health Tracking Network, yearly averages Oregon supplied to CDC, 2020 to 2023, read Oct. 8, 2026. TapBuff’s comparisons with EPA’s limits are its own, not CDC’s or Oregon’s.
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: Oregon Environmental Laboratory Accreditation Program, drinking water labs, as listed in TNI LAMS, read Oct. 13, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID OR4100061. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and CDC’s records for this utility. They don’t cover everything, which is why the next step matters.Every contaminant TapBuff tracks
- Get the utility’s own reportKnappa Water Association must send you a water quality report every year. It covers contaminants this page does not show, and has newer results than EPA’s national file for the ones here that come from it.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Decide if you want a filter at allA filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.NSF/ANSI standards, decoded