Walnut Grove, CA: 7 Health Violations — 75/100 (2026)
1 ZIP code · 5 water systems · Updated 2026-06-03
Although water quality varies across any metro, Walnut Grove's systems collectively post above-average compliance scores for CA — and documented violations are few.
How Walnut Grove Compares
Data: EPA SDWIS Last verified: 2026-06-03
Walnut Grove Water: The Quick Version
- Your city's water systems recorded 8 violations in the past 5 years.
- Average lead level: 0.0009 mg/L.
- Homes built before 1986: 78% — older plumbing may contain lead solder.
- Estimated remediation: $2,400 per household.
- CDC health risk index: 11.66.
Water Systems Serving Walnut Grove
Water service in Walnut Grove, CA is split across 3 utilities out of 5 tracked federally, each operating its own infrastructure and compliance record.
Overview
We track water quality and home safety data for 1 ZIP code in Walnut Grove, California (population ~1,793), covering 5 community water systems serving approximately 10,797 people region-wide.
1 of 1 ZIP code (100%) have recorded EPA violations. 7 health-based violations documented.
Home Safety Score
Average Home Safety Score for Walnut Grove: B (75/100)
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
Walnut Grove water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0009 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 3 (Low Risk)
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 8 | 1 |
| Consumer Confidence Report Rule | Reporting | 4 | 1 |
| Barium | Inorganic | 2 | 1 |
| Stage 1 DBP Rule | Treatment Technique | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 95690 | B | 8 | 7 | CITY OF RIO VISTA |
All ZIP Codes in Walnut Grove
- 95690 [B] — 8 violations ⚠
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 Walnut Grove
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 Walnut Grove
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is Walnut Grove's Housing Stock?
With 78% 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
Decades of residential development in Walnut Grove took place before the two main regulatory milestones that reduced plumbing-era lead risk: the phase-out of lead pipes before 1970, and the federal ban on lead solder in 1986. With a median build year of 1942, the housing stock here is anchored in that earlier period. The distinction between pre-1970 and 1970-to-1986 construction matters: the oldest homes may have lead pipes in the service line and lead solder in the copper joints, while the 1970-to-1986 tier still carries the solder risk even after lead pipes became less common. Together, these two risk layers affect a majority of the residential properties in the city — a fact the aggregate water quality data doesn't directly reveal.
Over half of homes in Walnut Grove 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.
Walnut Grove: Remediation Cost in Perspective
Low proportionality — that's the Walnut Grove picture when remediation costs are placed against typical home equity.
Remediation costs in Walnut Grove are relatively low compared to home values. The $1,500–$4,000 estimated range is a small fraction of median property value. Home values are 4% below the California average.
Protecting Children from Lead in Walnut Grove
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.
Reading the local data together points toward a structural gap that matters more here than in low-exposure communities. 78% of Walnut Grove stock comes from the pre-rule era, and citywide monitoring either approaches or sits beyond the federal benchmark under Lead and Copper Rule sampling. A baseline kit fits the routine-diligence category, with certified filtration available via retailer networks where confirmed faucet results warrant additional measures.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Walnut Grove
A moderate NFIP record for Walnut Grove — 135 insurance claims paired with 100% of ZIP codes in FEMA flood zones — points to a flood history where water-quality pathways have likely been periodically relevant.
Walnut Grove has a moderate flood history with 135 FEMA claims averaging $21,915 per payout. 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>$2,400</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.
Deep Dive Reports
Detailed analysis for Walnut Grove, CA