PlainWater

ROSARIO

PWS ID: WA5374270 · Tacoma, Washington 98444

ROSARIO serves 1,031 people in Tacoma, Washington using Surface Water water sources. It has 54 recorded EPA violations, including 8 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: ROSARIO

ROSARIO is a private-owned community water system that delivers drinking water to 1,031 residents in Tacoma, Washington (San Juan County) through 246 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 54 total violations for this system , of which 8 (15%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 45 monitoring and reporting violations are on file. The most recent violation on record dates to 2010.

The most frequently cited contaminant at this system is Surface Water Treatment Rule, recorded in 11 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. ROSARIO's 54 violations sit below the Washington average. Statewide, 98 of 247 UCMR5-tested systems have reported PFAS detections (39.7%). 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
1,031
Total Violations
54
Health-Based Violations
8
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Private
Connections
246
County
San Juan
School/Daycare
No
MCL Violations
0
Monitoring Violations
45
Treatment Tech Violations
8

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Surface Water Treatment Rule MR 11 2010
Surface Water Treatment Rule TT 8 2010
Coliform (TCR) MR 3 1992
Asbestos MR 2 2010
cis-1,2-Dichloroethylene MR 1 2004
o-Dichlorobenzene MR 1 2004
p-Dichlorobenzene MR 1 2004
Vinyl chloride MR 1 2004
1,1-Dichloroethylene MR 1 2004
trans-1,2-Dichloroethylene MR 1 2004
1,2-Dichloropropane MR 1 2004
Trichloroethylene MR 1 2004
Tetrachloroethylene MR 1 2004
CHLOROBENZENE MR 1 2004
Benzene MR 1 2004
Ethylbenzene MR 1 2004
Mercury MR 1 1979
Gross Alpha, Excl. Radon and U MR 1 1979
Barium MR 1 1979
Arsenic MR 1 1979
Fluoride MR 1 1979
Nitrate MR 1 1979
Chromium MR 1 1979
Styrene MR 1 2004
Selenium MR 1 1979
1,2,4-Trichlorobenzene MR 1 2004
DICHLOROMETHANE MR 1 2004
Toluene MR 1 2004
1,1,2-Trichloroethane MR 1 2004
1,2-Dichloroethane MR 1 2004

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 ROSARIO.

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 WA5374270 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 ROSARIO 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
2010 Surface Water Treatment Rule MR 11 SDWIS / WA5374270 / 0200
2010 Surface Water Treatment Rule TT 8 SDWIS / WA5374270 / 0200
2010 Asbestos MR 2 SDWIS / WA5374270 / 1094
2004 cis-1,2-Dichloroethylene MR 1 SDWIS / WA5374270 / 2380
2004 o-Dichlorobenzene MR 1 SDWIS / WA5374270 / 2968
2004 p-Dichlorobenzene MR 1 SDWIS / WA5374270 / 2969
2004 Vinyl chloride MR 1 SDWIS / WA5374270 / 2976
2004 1,1-Dichloroethylene MR 1 SDWIS / WA5374270 / 2977
2004 trans-1,2-Dichloroethylene MR 1 SDWIS / WA5374270 / 2979
2004 1,2-Dichloropropane MR 1 SDWIS / WA5374270 / 2983
2004 Trichloroethylene MR 1 SDWIS / WA5374270 / 2984
2004 Tetrachloroethylene MR 1 SDWIS / WA5374270 / 2987
2004 CHLOROBENZENE MR 1 SDWIS / WA5374270 / 2989
2004 Benzene MR 1 SDWIS / WA5374270 / 2990
2004 Ethylbenzene MR 1 SDWIS / WA5374270 / 2992

How ROSARIO Compares

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

Metric ROSARIO Washington avg Federal benchmark
Total violations 54 69 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 8 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 1,031 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
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is ROSARIO water safe to drink?
ROSARIO (PWS ID: WA5374270) has 54 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,031 people using Surface Water sources.
How many people does ROSARIO serve?
ROSARIO serves 1,031 people in Tacoma, Washington. It is a Private-owned system using Surface Water water sources with 246 service connections.
What type of violations does ROSARIO have?
ROSARIO has 54 total violations: 8 health-based violations (MCL exceedances or treatment failures), 45 monitoring/reporting violations, and 8 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in ROSARIO water?
No PFAS testing data is available for ROSARIO under the EPA's UCMR5 monitoring program.
What water source does ROSARIO use?
ROSARIO uses Surface Water 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.

Explore PlainWater

Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Related

Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by Kiznis Studio Editorial