Skip to content
TapBuff
ZIP

North Slope Estates Property

What EPA’s and Washington’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
97 people
Connections
30
Water source
Groundwater
Based in
Pasco, WA
County
Franklin
Owner
Private
The ZIP code it serves

99301

The short answer

1 result is above EPA’s legal limit. The worst: Arsenic, above the legal limit. 2 health-based violations since 2016.

What handles it

What was found

Arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate: Washington’s own results, samples taken from Jan. 9, 2020 to Sept. 14, 2026, with EPA’s 2012 to 2019 file for earlier years.

Fluoride and chromium (total): EPA’s compliance monitoring file, samples taken from June 11, 2019 to June 11, 2019. Newer results are in the utility’s annual water quality report.

Above the legal limit1

Arsenic

Comes from the source

Above the legal limit

10.2ppb

Highest yearly average, 2020 to 2026

2026 average: 0.14 ppb

Averaged by year, the highest was 10.2 ppb, in 2024, which EPA rounds to 10 ppb to compare: at its legal limit of 10 ppb, not above it. Its highest single sample was 11.5 ppb. In 2026, the latest year on file, its eight samples averaged 0.14 ppb. EPA judges this limit at each sampling point, and recorded violations for arsenic at this utility in 2024 and 2025. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 9.0 ppb, in 2019.

What handles it

  • NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
  • NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”

Below EPA’s limits4

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

14.2ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 14.2 ppb, in 2026, below EPA’s legal limit of 80 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 38 ppb, in 2013.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.24ppm

Highest yearly average, 2019

Averaged by year, the highest was 0.24 ppm, in 2019, below EPA’s legal limit of 4.0 ppm. That is the only year on file.

What handles it

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

2.8ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 2.8 ppb, in 2026, below EPA’s legal limit of 60 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.6 ppb, in 2017.

What handles it

No certification claim covers this compound yet.

Nitrate

Comes from the source

Below EPA’s limits

0.41ppm

Highest sample; found in 1 of 9

2026: not found

The highest sample, in 2021, was 0.41 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, it wasn’t found in any of its two samples. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.6 ppm, in 2013.

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.
  • Chromium (total)
  • Lead

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.”

  • NSF/ANSI 53

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

    Other certifiers’ wording: Arsenic (III) (50 ppb influent level)

  • NSF/ANSI 58

    Claim: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

    Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)

At the tap, or for the whole house?

These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. 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 reverse osmosis systems, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
ArsenicA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJuly 1, 2025 to Sept. 30, 20250.011 MG/LArchived
ArsenicA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleApril 1, 2024 to June 30, 20240.012 MG/LArchived
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 3 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate results here are Washington’s own from 2020 on, with EPA’s national file for 2012 to 2019. Fluoride and chromium (total) come from EPA’s file alone, which ends in 2019. North Slope Estates Property’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; Washington’s results run from Jan. 9, 2020 to Sept. 14, 2026; EPA’s compliance samples are from June 11, 2019 to June 11, 2019.

Testing your own tap

North Slope Estates Property’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 Washington certifies.

The 3 labs Washington certifies closest to the area North Slope Estates Property serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Matrix Sciences International Inc. dba KTL

    Pasco, WA · under a mile

    Certified for nitrate, lead and copper, metals, minerals and other inorganics

    (509) 547-3838

  • RJ Lee Group, Inc. Columbia Basin Analytical Laboratories

    Pasco, WA · under a mile

    Certified for nitrate, lead and copper, metals, minerals and other inorganics

    (509) 792-1951

  • Benton-Franklin Health District Lab

    Kennewick, WA · about 16 miles

    Certified for bacteria, nitrate, minerals and other inorganics

    (509) 460-4206

All 84 certified labs for Washington

Sources

PWSID WA5310761. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Franklin County

All Washington utilities

What to do next