Water Quality in Walla Walla, WA: 10 Violations — Grade C
Grade C · Score 69/100 · 5 water systems · Updated 2026-05-03
Walla Walla's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
EPA files for Walla Walla, WA document 10 water violations — a record that encompasses health-based exceedances, monitoring and reporting failures, and any other compliance events registered for local public water systems across all available federal compliance records for this area.
Water Quality by ZIP Code in Walla Walla
Water quality varies across Walla Walla's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 99362 | C | 69 | 10 | 0 | View report → |
Water Quality Overview
Walla Walla, Washington receives a water quality grade of C with an overall score of 69 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Walla Walla have accumulated 10 EPA violations (all monitoring/reporting type). These violations are tracked across 1 ZIP codes serving approximately 47,127 people.
What Grade C Means
A grade of C indicates moderate compliance issues. Walla Walla's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.
Lead Levels
The average 90th percentile lead level across Walla Walla water systems is 0.0025 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 68% of homes built before 1986, Walla Walla has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Walla Walla is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Walla Walla
Walla Walla is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 47,127 people across 1 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 10 enforcement actions against water systems serving Walla Walla. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Walla Walla
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Walla Walla Water Systems
The following contaminants have been detected or caused violations across Walla Walla's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 2 | 1 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 1 | 1 | No |
| Surface Water Treatment Rule | Treatment Technique | N/A | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Walla Walla. Recent actions:
| Date | Action Type |
|---|---|
| 2025-09-26 | State Order Extension |
| 2025-07-08 | State Order Extension |
| 2024-11-25 | State Order Extension |
| 2024-09-03 | State Order Extension |
| 2024-08-05 | State Order Extension |
| 2024-06-11 | State Order Extension |
| 2023-07-05 | State Order Extension |
| 2022-02-16 | State Order Extension |
| 2021-10-05 | State Order Extension |
| 2021-08-24 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-09-26.
Walla Walla vs. Nearby Washington Cities
How Walla Walla's water quality compares to similar cities in Washington:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Walla Walla | C | 10 | 5 | 47,127 |
| Poulsbo | A | 2 | 5 | 48,334 |
| Longview | B | 4 | 2 | 49,301 |
| Edmonds | A | 2 | 2 | 50,426 |
Common Questions About Walla Walla Water
These are the most common questions residents search for about water quality in Walla Walla, Washington:
Is Walla Walla water hard or soft? Water hardness varies by source. Walla Walla's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Walla Walla tap water? Walla Walla's water receives a grade of C (69/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Walla Walla? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Walla Walla vs. Washington Average
Understanding how Walla Walla compares to the broader Washington average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Walla Walla.
ZIP Codes in Walla Walla
Walla Walla spans 1 ZIP code. The ZIP with the lowest water quality score is 99362. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.