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Community Water System · PWS WA5381400

South Auburn Water Association

Black Diamond, Washington 98010 - drinking water served from groundwater sources to 212 people, tracked in EPA SDWIS and UCMR5.

212
People served
189
EPA violations
4
Health-based
Untested
UCMR5 result

The verdict

EPA records 189 drinking-water violations at South Auburn Water Association, 2% of them health-based - above the Washington per-system average.

189
Total EPA violations on record
2%
Health-based (MCL / treatment failure)
212
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: South Auburn Water Association

South Auburn Water Association is a private-owned community water system that delivers drinking water to 212 residents in Black Diamond, Washington (King County) through 45 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 189 total violations for this system , of which 4 (2%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 179 monitoring and reporting violations are on file. The most recent violation on record dates to 2018.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 23 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, 66 of 247 UCMR5-tested systems have reported PFAS detections (26.7%).

South Auburn Water Association's 189 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
212
Total Violations
189
Health-Based Violations
4
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
45
County
King
School/Daycare
No
MCL Violations
4
Monitoring Violations
179
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 23 2004
Lead and Copper Rule MR 11 2007
Nitrate MR 8 2006
1,2,4-Trichlorobenzene MR 6 2014
cis-1,2-Dichloroethylene MR 6 2014
trans-1,2-Dichloroethylene MR 6 2014
1,2-Dichloroethane MR 6 2014
Carbon tetrachloride MR 6 2014
1,2-Dichloropropane MR 6 2014
Trichloroethylene MR 6 2014
1,1,2-Trichloroethane MR 6 2014
Tetrachloroethylene MR 6 2014
Benzene MR 6 2014
Toluene MR 6 2014
DICHLOROMETHANE MR 6 2014
o-Dichlorobenzene MR 6 2014
1,1,1-Trichloroethane MR 6 2014
CHLOROBENZENE MR 6 2014
Ethylbenzene MR 6 2014
Styrene MR 6 2014
1,1-Dichloroethylene MR 6 2014
p-Dichlorobenzene MR 6 2014
Vinyl chloride MR 6 2014
Consumer Confidence Rule Other 4 2018
Coliform (TCR) MCL 4 2005
Chromium MR 1 2002
Thallium, Total MR 1 2002
Nickel MR 1 2002
Pentachlorophenol MR 1 2005
Picloram MR 1 2005

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 South Auburn Water Association.

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 WA5381400 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 South Auburn Water Association 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
2018 Consumer Confidence Rule Other 4 SDWIS / WA5381400 / 7000
2014 1,2,4-Trichlorobenzene MR 6 SDWIS / WA5381400 / 2378
2014 cis-1,2-Dichloroethylene MR 6 SDWIS / WA5381400 / 2380
2014 trans-1,2-Dichloroethylene MR 6 SDWIS / WA5381400 / 2979
2014 1,2-Dichloroethane MR 6 SDWIS / WA5381400 / 2980
2014 Carbon tetrachloride MR 6 SDWIS / WA5381400 / 2982
2014 1,2-Dichloropropane MR 6 SDWIS / WA5381400 / 2983
2014 Trichloroethylene MR 6 SDWIS / WA5381400 / 2984
2014 1,1,2-Trichloroethane MR 6 SDWIS / WA5381400 / 2985
2014 Tetrachloroethylene MR 6 SDWIS / WA5381400 / 2987
2014 Benzene MR 6 SDWIS / WA5381400 / 2990
2014 Toluene MR 6 SDWIS / WA5381400 / 2991
2014 DICHLOROMETHANE MR 6 SDWIS / WA5381400 / 2964
2014 o-Dichlorobenzene MR 6 SDWIS / WA5381400 / 2968
2014 1,1,1-Trichloroethane MR 6 SDWIS / WA5381400 / 2981

How South Auburn Water Association Compares

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

Metric South Auburn Water Association Washington avg Federal benchmark
Total violations 189 69 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 4 4.5 Indicates a contaminant exceeded a federal MCL
PFAS detection None 26.7% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 212 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 South Auburn Water Association water safe to drink? ▼
South Auburn Water Association (PWS ID: WA5381400) has 189 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 212 people using Groundwater sources.
How many people does South Auburn Water Association serve? ▼
South Auburn Water Association serves 212 people in Black Diamond, Washington. It is a Private-owned system using Groundwater water sources with 45 service connections.
What type of violations does South Auburn Water Association have? ▼
South Auburn Water Association has 189 total violations: 4 health-based violations (MCL exceedances or treatment failures), 179 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in South Auburn Water Association water? ▼
No PFAS testing data is available for South Auburn Water Association under the EPA's UCMR5 monitoring program.
What water source does South Auburn Water Association use? ▼
South Auburn Water Association 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.