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WaterSafeCheck

ZIP Code 99336 Water Quality Report

Kennewick, WA · Benton County County

Safety Score
C

Water Safety Grade

Fair — Some compliance concerns

Health Violations

7

Total Violations

13

Lead Risk

Moderate

Contaminants

2

⚠

Active Water Quality Issues Detected

EPA records show 10 unresolved violations. Contact City of Kennewick for current status.

About Tap Water in ZIP Code 99336

Tap water in ZIP code 99336 (Kennewick, WA) receives a C grade (score: 58/100) based on EPA monitoring data. While the water from City of Kennewick is treated and regulated, this area has a moderate violation history that residents should be aware of.

Water System

City of Kennewick

EPA ID: WA5338100

Water Source

Surface Water

Population Served

114,468 residents

County

Benton County County, Washington

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Lead Levels in ZIP 99336

EPA action level: 15 ppb | Public health goal: 0 ppb

Lead Level: 1.9 ppb — Very Low

The 90th percentile lead level in 99336 is 1.9 ppb, well below the EPA action level of 15 ppb. While this is a reassuring result, the EPA's public health goal for lead is actually zero — no amount of lead is considered completely safe, particularly for children under 6 and pregnant women. Running your tap for 30 seconds before use and using a certified NSF/ANSI 53 filter adds an extra layer of protection.

Lead exposure risk in 99336 is rated Moderate. EPA models estimate a 41% probability of lead exposure risk in this ZIP code based on housing age, infrastructure age, and water system data. This may reflect a mix of older and newer housing stock and infrastructure. Families with young children should test their home's water and consider a certified NSF/ANSI 53 water filter.

Lead Level (90th percentile)
1.90 ppb (0.0019 mg/L)
Lead (Consumer Confidence Report)

From annual CCR filing

1.4 ppb
Copper (Consumer Confidence Report)

From annual CCR filing

0.2 ppb
Lead Exposure Risk Rating
Moderate
Lead Exposure Probability

EPA model estimate based on housing age and infrastructure

41%
Note: Lead levels above are the 90th percentile from EPA monitoring — meaning 90% of samples were at or below this level. Even "undetected" tap water lead doesn't account for lead leaching from home plumbing. If your home was built before 1986, individual tap testing is recommended.
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Violation History

Past 5 years — EPA SDWIS data

City of Kennewick has recorded 7 health-based violations in the past 5 years — significantly above the national average. This volume of violations indicates serious and recurring compliance issues. Independent water testing and in-home filtration are strongly recommended. 10 violations are currently unresolved — meaning the issue has not yet been formally corrected in EPA records. This is a serious concern that residents should follow up on with their water utility.

Total Violations (5 yr)
13
Health-Based Violations
7
Unresolved Violations
10
Boil Water Advisories
0
Compliance Risk
Critical

Regulatory compliance risk is rated Critical — the highest risk category. City of Kennewick has an extensive history of unresolved violations and enforcement actions. Independent water testing is highly recommended.

⚗️

Contaminants Detected

Contaminants with health-based violations on record

EPA records identify 2 contaminants associated with health-based violations in ZIP code 99336: Haloacetic Acids (HAA5), Total Trihalomethanes (TTHM). These contaminants exceeded the Maximum Contaminant Levels (MCLs) established by the EPA under the Safe Drinking Water Act at some point in the 5-year monitoring period. The presence of these violations does not necessarily mean water is currently unsafe — water systems are often required to increase monitoring and treatment when violations occur. Review the annual Consumer Confidence Report for the most current status.

Haloacetic Acids (HAA5)Total Trihalomethanes (TTHM)

From Consumer Confidence Report:

Trihalomethane (TTHM) (42.6 ppb)

⚖ Enforcement Actions

7 enforcement actions have been issued against City of Kennewick — a high number that reflects sustained compliance struggles. Enforcement actions escalate from administrative orders to financial penalties when utilities repeatedly fail to meet safe drinking water standards.
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Water Source & Environmental Factors

Surface Water

This system draws water from lakes, rivers, or reservoirs. Surface water is treated to remove sediment, microorganisms, and chemical contaminants before reaching taps.

Water Source Type
Surface Water
CCR Source Classification
Mixed
EPA Radon Zone

Moderate potential

Zone 2
Annual Flood Risk Cost

Estimated annual flood-related costs per property

$0
Energy Burden

% of household income spent on energy — indicator of older infrastructure

6.9%

EPA Radon Zone 2 — moderate radon potential. The EPA recommends testing your home regardless of zone designation.

🛡 What Should You Do? — ZIP 99336 Recommendations

  • ⚠ Use a certified NSF/ANSI 53 filter for drinking and cooking water if you have young children
  • ⚠ Never give unfiltered tap water to infants in formula — use certified bottled or filtered water
  • ⚠ Request a copy of the Consumer Confidence Report to see what was detected and when
  • ⚠ Call the EPA Safe Drinking Water Hotline: 1-800-426-4791

Frequently Asked Questions — ZIP 99336 Water Quality

Is tap water safe to drink in ZIP code 99336?+
Tap water in 99336 (Kennewick, WA) is treated and regulated, but has a grade of C due to past violations. For most healthy adults, treated tap water is generally safe. Families with infants, young children, or immunocompromised individuals may want to use a certified water filter as a precaution.
What is the lead level in 99336 tap water?+
The 90th percentile lead level in 99336 is 1.9 ppb (parts per billion). The EPA action level is 15 ppb. This is a low level, well below the EPA action level of 15 ppb.
Who provides tap water to 99336?+
Tap water in ZIP code 99336 is provided by City of Kennewick (EPA ID: WA5338100). This system serves approximately 114,468 residents. You can contact them directly for Consumer Confidence Reports, current advisories, and billing information.
What is the water source for 99336?+
ZIP code 99336 is served by surface water. Surface water systems draw from rivers, lakes, or reservoirs and must meet strict EPA treatment requirements including filtration and disinfection.
Does 99336 have any active water quality violations?+
Yes — there are currently 10 unresolved violations on record for this water system. Unresolved violations indicate issues that have not yet been formally corrected in EPA tracking systems. Contact City of Kennewick for the latest update.
How do I get a copy of my water quality report for 99336?+
Your water utility — City of Kennewick — is required by law to send you an annual Consumer Confidence Report (CCR) by July 1 each year. You can also request it directly from the utility or find it online by searching "City of Kennewick Consumer Confidence Report." The EPA's ECHO database also has historical compliance data.
What water filter should I use in 99336?+
The right filter depends on what contaminants are present. For lead, look for a filter certified to NSF/ANSI Standard 53. For chlorine byproducts (like THMs), NSF/ANSI 42 filters work well. For a broad range of contaminants including PFAS, look for NSF/ANSI 58 (reverse osmosis) systems. For ZIP code 99336, with detected contaminants including Haloacetic Acids (HAA5) and Total Trihalomethanes (TTHM), a multi-stage filter or reverse osmosis system is recommended.
Is 99336 tap water safe for babies and infants?+
Infants are especially vulnerable to lead, nitrates, and microbial contaminants in drinking water. Current EPA data for 99336 shows a lead level of 1.9 ppb — below the action level, but as an extra precaution, run your tap for 30 seconds before use and consider a certified lead filter for infant formula. Always consult your pediatrician for guidance specific to your child's health.

Data Sources & Methodology

Water quality data for ZIP code 99336 is compiled from the EPA Safe Drinking Water Information System (SDWIS), EPA ECHO enforcement database, UCMR5 unregulated contaminant monitoring, and Consumer Confidence Reports filed by City of Kennewick. Safety scores are composite metrics derived from violation history, lead levels, enforcement actions, and infrastructure risk indicators. Data reflects a 5-year monitoring window. Last dataset update: 2024. View EPA source data →