How does Kennewick's water compare to the national average?

The USA national average is 151 mg/L. Kennewick (≈ 120–179 mg/L) is 1 mg/L softer than average.

Kennewick Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

reservoir

pH Level

7.7

neutral = 7.0

Lead

0.008 mg/L

✓ Below action level

TDS

193.9 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · est.

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In Kennewick, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In Kennewick	Soft Water City	Efficiency Loss
Kettle	6.8 yrs	8.5 yrs	-20%
Washing Machine	9.6 yrs	12 yrs	-20%
Water Heater	12 yrs	15 yrs	-20%

Regional Water Comparison

How Kennewick compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Kennewick, Washington	≈ 120–179 mg/L	162.6 ppt	🟠 Hard	reservoir
Pasco, Washington	≈ 0–60 mg/L	0 ppt	🟢 Soft	reservoir
Tri-Cities, Washington	≈ 120–179 mg/L	1.6 ppt	🟠 Hard	reservoir
Richland, Washington	≈ 120–179 mg/L	114.7 ppt	🟠 Hard	reservoir
West Richland, Washington	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir

National Benchmark

How Kennewick compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Kennewick	≈ 120–179 mg/L	🟠 Moderate
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Kennewick's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 193.9 mg/LpH: 7.7

The City of Kennewick Water Division supplies potable water to customers in Kennewick, Washington, primarily within Benton County. Water sources include the Columbia River, treated at the Columbia River Water Treatment Plant (39% of production), and Ranney Collector 4 and Ranney Collector 5 Wells (61% combined), which undergo riverbank filtration. River water is treated via flocculation, sedimentation, membrane filtration, UV disinfection, and chlorination; Ranney wells receive UV treatment and chloramination due to their classification under direct groundwater influence.

The Columbia River watershed drains the Cascade Range and Columbia Plateau, with headwaters in British Columbia and flow through volcanic and sedimentary terrains before reaching the Pasco Basin near Kennewick. Local geology features the Wanapum and Saddle Mountains Formations of Miocene basalt, capped by thick Quaternary loess, sand, and gravel from repeated glacial outburst floods. This aquifer system imparts a hard character to the blended supply through natural mineral dissolution, with riverbank filtration enhancing contact with mineral-rich sediments.

Hard water promotes limescale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan. Affected appliances show white deposits, reduced flow, and higher energy use. Regular vinegar descaling, installing drain screens, and using high-temperature settings help mitigate issues. A water softener is recommended to prevent scaling and protect plumbing. Water quality scores D+ overall per third-party analysis, with arsenic detected above health guidelines from natural soil sources — long-term exposure risks are monitored per regulation. The utility provides CCR links for full compliance details.

Geology & Source: Pasco Basin; Miocene Wanapum and Saddle Mountains basalt overlain by Quaternary loess and Lake Missoula flood gravels; basalts and alluvial sediments dissolve calcium and magnesium — hard blended supply

Other Washington Water Reports

Pasco

≈ 0–60 mg/L

🟢 Soft

Tri-Cities

≈ 120–179 mg/L

🟠 Hard

Richland

≈ 120–179 mg/L

🟠 Hard

West Richland

≈ 120–179 mg/L

🟠 Hard

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Frequently Asked Questions

Is Kennewick's water safe to drink?

Yes. Kennewick's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Kennewick?

At ≈ 120–179 mg/L (Hard), Kennewick's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.

How does Kennewick compare to the USA average?

The USA national average is 151 mg/L. Kennewick (≈ 120–179 mg/L) is 1 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Kennewick is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.