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ONSLOW WATER SUPPLY

PWS ID: IA5358096 · WYOMING, Iowa 52362

ONSLOW WATER SUPPLY serves 201 people in WYOMING, Iowa using Groundwater water sources. It has 123 recorded EPA violations, including 0 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: ONSLOW WATER SUPPLY

ONSLOW WATER SUPPLY is a local-owned community water system that delivers drinking water to 201 residents in WYOMING, Iowa (Jones County) through 110 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 123 total violations for this system , of which 0 (0%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 67 monitoring and reporting violations are on file. The most recent violation on record dates to 2022.

The most frequently cited contaminant at this system is Nitrate, recorded in 19 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 Iowa, EPA tracks 1,795 public water systems serving 3,114,444 people, with 138,271 cumulative violations and 27,946 health-based violations on record. About 95% of systems in the state carry at least one violation, and state-wide the average per system is 77 violations. ONSLOW WATER SUPPLY's 123 violations sit above the Iowa average. Statewide, 127 of 152 UCMR5-tested systems have reported PFAS detections (83.6%). 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
201
Total Violations
123
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
110
County
Jones
School/Daycare
No
MCL Violations
0
Monitoring Violations
67
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Nitrate MR 19 2022
Consumer Confidence Rule Other 14 2019
Lead and Copper Rule MR 13 2012
Selenium MR 6 1987
Fluoride MR 5 1987
Arsenic MR 3 1987
Mercury MR 3 1987
1,2,4-Trichlorobenzene MR 3 1996
BHC-GAMMA MR 3 1995
Barium MR 3 1987
Chromium MR 3 1987
Coliform (TCR) MR 3 2002
Cadmium MR 3 1987

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 ONSLOW WATER SUPPLY.

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 IA5358096 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Iowa Drinking Water Authority

Iowa's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find IA regulator via EPA SDWIS

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
2022 Nitrate MR 19 SDWIS / IA5358096 / 1040
2019 Consumer Confidence Rule Other 14 SDWIS / IA5358096 / 7000
2012 Lead and Copper Rule MR 13 SDWIS / IA5358096 / 5000
2002 Coliform (TCR) MR 3 SDWIS / IA5358096 / 3100
1996 1,2,4-Trichlorobenzene MR 3 SDWIS / IA5358096 / 2378
1995 BHC-GAMMA MR 3 SDWIS / IA5358096 / 2010
1987 Selenium MR 6 SDWIS / IA5358096 / 1045
1987 Fluoride MR 5 SDWIS / IA5358096 / 1025
1987 Arsenic MR 3 SDWIS / IA5358096 / 1005
1987 Mercury MR 3 SDWIS / IA5358096 / 1035
1987 Barium MR 3 SDWIS / IA5358096 / 1010
1987 Chromium MR 3 SDWIS / IA5358096 / 1020
1987 Cadmium MR 3 SDWIS / IA5358096 / 1015

How ONSLOW WATER SUPPLY Compares

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

Metric ONSLOW WATER SUPPLY Iowa avg Federal benchmark
Total violations 123 77 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 0 15.6 Indicates a contaminant exceeded a federal MCL
PFAS detection None 83.6% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 201 1,735 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 1,795 regulated public water systems in Iowa.

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 ONSLOW WATER SUPPLY water safe to drink?
ONSLOW WATER SUPPLY (PWS ID: IA5358096) has 123 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 201 people using Groundwater sources.
How many people does ONSLOW WATER SUPPLY serve?
ONSLOW WATER SUPPLY serves 201 people in WYOMING, Iowa. It is a Local-owned system using Groundwater water sources with 110 service connections.
What type of violations does ONSLOW WATER SUPPLY have?
ONSLOW WATER SUPPLY has 123 total violations: 0 health-based violations (MCL exceedances or treatment failures), 67 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in ONSLOW WATER SUPPLY water?
No PFAS testing data is available for ONSLOW WATER SUPPLY under the EPA's UCMR5 monitoring program.
What water source does ONSLOW WATER SUPPLY use?
ONSLOW WATER SUPPLY 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.

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 PlainWater Editorial