Is Zillah, WA Tap Water Safe to Drink?
Graded D+, with 23 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
50/100
waterverge.com Zillah, WA — Water Quality Report
Zillah's drinking water received a grade of D+ (50 out of 100), indicating poor water quality. The city's 2 water systems serve approximately 3,563 residents using groundwater.
Lead levels were measured at 1.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 240 violations on record, including 11 health-based violations. 23 remain unresolved.
What to know about Zillah's water
Zillah ranks #215 out of 294 cities in Washington for water quality, placing it below average in the state.
Zillah relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
The system has seen 18 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Zillah, WA water safe to drink?
Zillah's drinking water has significant quality concerns based on EPA testing data. With a grade of D+ (50/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 3,563 residents using groundwater (wells).
Recent water quality updates for Zillah
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Zillah's water quality assessment. Grade: D+ (50/100).
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-3629). Flood event — may have impacted local water infrastructure.
Contaminants: Lead and Copper Rule.
Contaminants: Chlorine, Revised Total Coliform Rule.
Federal disaster declaration (FEMA DR-1817). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Zillah's water supply.
Well within EPA limits.
Violation history
Zillah's water system has 240 total violations on record, including 11 health-based violations. 23 remain unresolved. 18 violations were issued in the last 5 years.
Flood & environmental risk
Yakima County has experienced 10 federally declared disasters since 1964. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Granger Drain.
Where does Zillah's water come from?
Zillah's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 3,563 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Granger Drain (river).
What Zillah residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Zillah's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Zillah's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Zillah
Industrial polluters nearby
Reported releases to surface water by facilities near Zillah, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
CARGILL FEED & NUTRITION GRANGER GRANGER, WA98932 | — | — | 4.9 mi |
YAKIMA BAIT CO/WORDEN'S LURE GRANGER, WA98932 | — | — | 6.1 mi |
WASHINGTON BEEF LLC TOPPENISH, WA98948 | — | — | 3.8 mi |
MCCLARIN PLASTICS LLC WAPATO, WA98951 | — | — | 8.4 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Drought conditions
D1 — moderate droughtYakima County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Yakima County has experienced 10 federally declared disasters since 1964. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 1.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Zillah compares by contaminant
Explore where Zillah ranks among all Washington cities for specific contaminants.
Water source & infrastructure
Where Zillah's water comes from
Zillah's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by local government ownership and serves approximately 3,563 people through 2 water systems.
Water bodies near Zillah
Zillah is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Zillah
| System Name | PWSID | Population | Source |
|---|---|---|---|
| ZILLAH CITY OF | WA5399800 | 3,518 | GW |
| B & D MOBILE COURT | 105300073 | 45 | GW |
How Zillah compares
Full Washington rankings →Zillah's score of 50/100 is on par with the average of 53/100 among major Washington cities. It outscores 6 of 10 nearby cities.
Nearby cities
View Washington rankings →About Zillah, WA
Wikipedia →Zillah is a city in Yakima County, Washington, United States, with a population of 3,179 as of the 2020 census.
Learn more about your water
Guides and resources related to Zillah's water quality findings.
Explore water quality across Yakima
Frequently asked questions
Is Zillah, WA tap water safe to drink?
Zillah's water quality earned a grade of D+ (50/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #215 out of 294 cities tested in Washington.
What contaminants are in Zillah's water?
Lead was measured at 1.0 ppb (90th percentile). 240 violations are on record.
How is Zillah's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Zillah?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Zillah's water come from?
Zillah's water is sourced from Groundwater. The city has 2 water systems serving approximately 3,563 residents.
What health violations has Zillah's water system had?
Zillah has 11 health-based violations on record. The most recent violation was recorded in December 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 23 violations remain unresolved.
Is Zillah's groundwater at risk of contamination?
Zillah uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 240 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Zillah's water compare to other cities?
Zillah ranks #215 out of 294 cities in Washington (better than 27% of state cities) and #13080 out of 15744 cities nationally (17th percentile). The grade of D+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.