Onslow, IA: 1 Violation — 66/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Onslow, IA: mid-range safety grade, uneven compliance across service areas.
How Onslow Compares
Data: EPA SDWIS Last verified: 2026-06-03
Onslow Water: The Quick Version
- Your city's water systems recorded 1 violation in the past 5 years.
- Average lead level: 0.0006 mg/L.
- Homes built before 1986: 88% — older plumbing may contain lead solder.
- Estimated remediation: $1,200 per household.
- CDC health risk index: 13.93 — above typical levels.
Water Systems Serving Onslow
In Onslow, IA, the drinking water supply is organized under a single dominant utility — a consolidated structure that shapes how infrastructure investment, regulatory compliance, and rate decisions flow to households. When one provider handles the overwhelming share of residential connections out of 1 tracked system, accountability is clear: service upgrades, EPA violation responses, and tariff changes all funnel through that single organizational structure.
Overview
We track water quality and home safety data for 1 ZIP code in Onslow, Iowa, covering 1 community water system serving approximately 456 people.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Onslow: C (66/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Onslow water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0006 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Lead | Inorganic | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 52321 | C | 1 | 0 | Onslow Water Supply |
All ZIP Codes in Onslow
- 52321 [C] — 1 violation
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
CDC Health Data for Onslow
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Key Contaminants Detected in Onslow
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is Onslow's Housing Stock?
With 88% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Reading the housing age data for Onslow — median build year 1901 — the overriding implication is that the plumbing materials inside a typical home here reflect pre-1986 construction standards. In practical terms, that means lead-soldered copper joints are common across much of the housing stock. Where those materials are present, water can leach lead as it moves through joints — a pathway that corrosion control treatment under federal rules is designed to reduce, though it cannot eliminate lead risk where the plumbing materials themselves contain lead.
Over half of homes in Onslow were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Onslow: Remediation Cost in Perspective
In Onslow, documented water and safety issues can be addressed without making a meaningful dent in home equity — the financial proportionality here is favorable, and the commitment fits within standard property planning frameworks.
Remediation costs in Onslow are relatively low compared to home values. The $800–$1,500 estimated range is a small fraction of median property value. Home values are 26% below the Iowa average.
Protecting Children from Lead in Onslow
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Practically, the structural drivers in Onslow — 88% pre-rule stock and citywide monitoring at or beyond the regulatory benchmark — make an in-home draw the practical way to translate aggregate averages into the specific conditions at one address.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
What You Can Do in Onslow
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. Filters rated for Lead can reduce the most common contaminant found in Onslow's water.
- Check your home's plumbing. With 88% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Onslow, IA