Posey, CA Water Safety: 63/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Compared to top-scoring cities in CA, Posey lands in the middle tier — some water systems meet standards cleanly, others carry documented violations, and performance can vary significantly across service areas.
How Posey Compares
Data: EPA SDWIS Last verified: 2026-06-03
Posey Water: The Quick Version
- Homes built before 1986: 75% — older plumbing may contain lead solder.
- Estimated remediation: $2,200 per household.
- CDC health risk index: 12.22 — above typical levels.
Water Systems Serving Posey
In Posey, CA, 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 Posey, California, covering 1 community water system serving approximately 151 people.
No EPA violations recorded across any ZIP codes in Posey — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Posey: C (63/100)
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
Posey water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Posey
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 93260 | C | GLENNVILLE MUTUAL WATER COMPANY | 100 |
All ZIP Codes in Posey
- 93260 [C]
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 Posey
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
How Old Is Posey's Housing Stock?
With 75% 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
What does a median build year of 1974 mean for water safety in Posey? It means the majority of the city's residential plumbing was installed before 1986, when lead solder was federally banned, and a large share may predate 1970, when lead pipes were commonly used — making plumbing age a central variable in household-level lead risk across much of the city.
Over half of homes in Posey 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.
Posey: Remediation Cost in Perspective
Property equity in Posey runs well ahead of estimated remediation costs — a cost-to-value ratio that sits in the low tier, meaning documented water and safety issues here are the kind homeowners can plan to address without treating the expense as a significant budget event relative to what their homes are worth.
Remediation costs in Posey are relatively low compared to home values. The $1,200–$3,300 estimated range is a small fraction of median property value. Home values are 51% below the California average.
Protecting Children from Lead in Posey
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.
If 75% of the Posey inventory comes from before the federal ban on lead-bearing solder — and if utility samples sit at or near 0.015 mg/L — the gap between citywide averages and one specific faucet becomes a practical concern rather than a theoretical one. That is why one-home reads exist as a separate measurement. A certified filter through retailer networks addresses confirmed exposure where it appears in a household.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Posey
Multiple flood events have been recorded for Posey through the NFIP — 1 claim in total, with 100% of ZIP codes in FEMA-designated zones — pointing to a flood exposure profile that merits inclusion in a water quality assessment without reaching high-severity planning territory.
Posey has a moderate flood history with 1 FEMA claims. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$2,200</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
What You Can Do in Posey
- 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. An NSF-certified pitcher or under-sink filter removes most common contaminants.
- Check your home's plumbing. With 75% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Posey, CA