Big Oak Flat, CA: 4 Health Violations - Home Safety 56/100
1 ZIP code · 3 water systems · Updated
ZipCheckup grade for Big Oak Flat: C.
A mixed picture - some signals here are worth your attention.
Big Oak Flat, CA holds a middle-tier grade; review the underlying water system records for the reasons behind it.
How Big Oak Flat Compares
Data: EPA SDWIS
What You Should Know About Big Oak Flat Water
- Your city's water systems recorded 10 violations since 2021.
- Homes built before 1986: 96% - older plumbing may contain lead solder.
- Estimated remediation: $1,100 per household.
- Health risk index (ZipCheckup composite of CDC data): 13.17.
Who Supplies Your Water in Big Oak Flat
Because each listed system has its own federal record, violations at one of the 3 shown below do not apply to the others among the 3 tied to Big Oak Flat, CA.
- C
- C
- C
Overview
We track home safety data for 1 ZIP code in Big Oak Flat, California (population ~203), covering 3 community water systems serving approximately 17,694 people region-wide. The EPA snapshots used for this build directly map water systems to 1 of 1 ZIP codes.
1 of 1 ZIP code with a reported violation count in the available EPA record (100%) have recorded EPA violations. 4 health-based violations appear in the available health breakdown.
Home Safety Score
Average Home Safety Score for Big Oak Flat: C (56/100)
Model 4.0.0 uses four measured components across three equally weighted domains. If a required domain is unavailable, no score is published:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| PFAS MCL Screen | UCMR 5 testing against the covered federal MCLs |
| Radon Risk | EPA radon zone classification |
| Annual AQI | EPA AirData county-year median with at least 90 observed days |
Water Sources
Big Oak Flat water systems draw from: Surface water.
Lead & Copper
- Average of reported 90th-percentile lead results: reported as 0 mg/L (a reported 0 is not proof of no lead; check the source record for its reporting limit) (EPA action level: 0.015 mg/L)
- 0 of 1 ZIP code with known status exceed the EPA lead action level
Radon Risk
1 of 1 ZIP records with known zones is in EPA Radon Zone 2.
The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Lead and Copper Rule Revisions | Treatment Technique | 8 | 1 |
| Nitrate | Inorganic | 4 | 1 |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 4 | 1 |
| Revised Total Coliform Rule | Microbiological | 4 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 95305 | C | 10 | 4 | Groveland Community Serv District |
All ZIP Codes in Big Oak Flat
- 95305 [C] - 10 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
Reporting periods vary by source. Missing data is shown as unavailable, not as zero.
Health Outcomes in Big Oak Flat
Source: CDC PLACES (County-level estimates). County health indicators are shown for context only and are not linked to this area's water records.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Top Contaminants in Big Oak Flat Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Big Oak Flat
With 96% of homes built before 1986, lead solder in plumbing is a potential concern. Federal law banned lead solder in drinking-water plumbing in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Viewed through the lens of construction era, Big Oak Flat has a median build year of 1975; houses completed ahead of 1986 can hold lead-bearing solder or fittings.
Over half of homes in Big Oak Flat were built before 1986, when federal law began restricting lead solder in drinking-water plumbing. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Lead Exposure Risk for Children in Big Oak Flat
Why children are most at risk: The CDC states that no safe blood lead level in children has been identified. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
If you have young children or are pregnant, consider testing your home's water - especially if your home was built before 1986.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
What You Can Do in Big Oak Flat
- Test your water at home. City-level data shows averages - your tap may differ. Check the certification, price and turnaround time of any water test kit or lab service.
- Install a certified water filter. For Lead and Copper Rule Revisions, listed in the water-quality records for Big Oak Flat: if it is a rule or reporting requirement rather than a contaminant, ask your utility what the record involved; for bacteria, follow any boil-water notice from your utility; for a specific chemical contaminant, check whether a filter is certified to reduce it. Not every contaminant has a consumer filter certification.
- Check your home's plumbing. With 96% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Big Oak Flat, CA