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Community Water System · PWS WA5329550

Green Tank Irr District 11

Walla Walla, Washington 99362 - drinking water served from groundwater sources to 553 people, tracked in EPA SDWIS and UCMR5.

553
People served
524
EPA violations
2
Health-based
Untested
UCMR5 result

The verdict

EPA records 524 drinking-water violations at Green Tank Irr District 11 - above the Washington per-system average.

524
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
553
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Green Tank Irr District 11

Green Tank Irr District 11 is a local-owned community water system that delivers drinking water to 553 residents in Walla Walla, Washington (Walla Walla County) through 196 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 524 total violations for this system , of which 2 (0%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 518 monitoring and reporting violations are on file. The most recent violation on record dates to 2020.

The most frequently cited contaminant at this system is ETHYLENE DIBROMIDE, recorded in 20 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Washington, EPA tracks 4,557 public water systems serving 9,736,844 people, with 314,648 cumulative violations and 20,590 health-based violations on record. About 92% of systems in the state carry at least one violation, and state-wide the average per system is 69 violations. Statewide, 98 of 247 UCMR5-tested systems have reported PFAS detections (39.7%).

Green Tank Irr District 11's 524 violations sit above the Washington average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
553
Total Violations
524
Health-Based Violations
2
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
196
County
Walla Walla
School/Daycare
No
MCL Violations
2
Monitoring Violations
518
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
ETHYLENE DIBROMIDE MR 20 2007
1,2-DIBROMO-3-CHLOROPROPANE MR 20 2007
Pentachlorophenol MR 18 2017
Dinoseb MR 11 2017
cis-1,2-Dichloroethylene MR 11 2014
o-Dichlorobenzene MR 11 2014
p-Dichlorobenzene MR 11 2014
Vinyl chloride MR 11 2014
1,1-Dichloroethylene MR 11 2014
trans-1,2-Dichloroethylene MR 11 2014
1,1,1-Trichloroethane MR 11 2014
Carbon tetrachloride MR 11 2014
1,2-Dichloropropane MR 11 2014
1,1,2-Trichloroethane MR 11 2014
Tetrachloroethylene MR 11 2014
CHLOROBENZENE MR 11 2014
Toluene MR 11 2014
Ethylbenzene MR 11 2014
Styrene MR 11 2014
1,2,4-Trichlorobenzene MR 11 2014
1,2-Dichloroethane MR 11 2014
Benzene MR 11 2014
2,4,5-TP MR 11 2017
Dalapon MR 11 2017
Picloram MR 11 2017
Trichloroethylene MR 11 2014
DICHLOROMETHANE MR 11 2014
Endrin MR 10 2020
BHC-GAMMA MR 10 2020
Toxaphene MR 10 2020

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Green Tank Irr District 11.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID WA5329550 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Washington Drinking Water Authority

Washington State Department of Health, Office of Drinking Water is the primacy agency that licenses and inspects Green Tank Irr District 11 under EPA-delegated authority.

Open WA regulator portal

Source: Washington State Department of Health, Office of Drinking Water

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2020 Endrin MR 10 SDWIS / WA5329550 / 2005
2020 BHC-GAMMA MR 10 SDWIS / WA5329550 / 2010
2020 Toxaphene MR 10 SDWIS / WA5329550 / 2020
2020 Di(2-ethylhexyl) adipate MR 10 SDWIS / WA5329550 / 2035
2020 Simazine MR 10 SDWIS / WA5329550 / 2037
2020 Hexachlorocyclopentadiene MR 10 SDWIS / WA5329550 / 2042
2020 Atrazine MR 10 SDWIS / WA5329550 / 2050
2020 LASSO MR 10 SDWIS / WA5329550 / 2051
2020 Heptachlor MR 10 SDWIS / WA5329550 / 2065
2020 Heptachlor epoxide MR 10 SDWIS / WA5329550 / 2067
2020 Chlordane MR 10 SDWIS / WA5329550 / 2959
2020 Di(2-ethylhexyl) phthalate MR 10 SDWIS / WA5329550 / 2039
2020 Methoxychlor MR 10 SDWIS / WA5329550 / 2015
2020 HEXACHLOROBENZENE MR 10 SDWIS / WA5329550 / 2274
2020 Benzo(a)pyrene MR 10 SDWIS / WA5329550 / 2306

How Green Tank Irr District 11 Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Green Tank Irr District 11 Washington avg Federal benchmark
Total violations 524 69 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 2 4.5 Indicates a contaminant exceeded a federal MCL
PFAS detection None 39.7% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 553 2,137 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 4,557 regulated public water systems in Washington.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Green Tank Irr District 11 water safe to drink? ▼
Green Tank Irr District 11 (PWS ID: WA5329550) has 524 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 553 people using Groundwater sources.
How many people does Green Tank Irr District 11 serve? ▼
Green Tank Irr District 11 serves 553 people in Walla Walla, Washington. It is a Local-owned system using Groundwater water sources with 196 service connections.
What type of violations does Green Tank Irr District 11 have? ▼
Green Tank Irr District 11 has 524 total violations: 2 health-based violations (MCL exceedances or treatment failures), 518 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Green Tank Irr District 11 water? ▼
No PFAS testing data is available for Green Tank Irr District 11 under the EPA's UCMR5 monitoring program.
What water source does Green Tank Irr District 11 use? ▼
Green Tank Irr District 11 uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.