San Dimas, CA: 1 Violation - Home Safety 58/100
1 ZIP code · 4 water systems · Updated
ZipCheckup grade for San Dimas: C.
A mixed picture - some signals here are worth your attention.
For most households in San Dimas, CA tap water is adequate - the middle-tier grade reflects gaps in specific service areas.
How San Dimas Compares
Data: EPA SDWIS
San Dimas Water: The Quick Version
- Your city's water systems recorded 1 violation in the past 5 years.
- Average lead level: 0.0021 mg/L.
- Homes built before 1986: 77% - older plumbing may contain lead solder.
- Estimated remediation: $1,800 per household.
- CDC health risk index: 10.71.
Water Systems Serving San Dimas
4 water systems are tracked federally in San Dimas, CA. The top 3 providers collectively serve most residential addresses, but because they operate independently, infrastructure maintenance standards and compliance histories differ from one service zone to another.
- C
- C
- C
Overview
We track home safety data for 1 ZIP code in San Dimas, California (population ~33,917), covering 4 community water systems serving approximately 141,209 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. The available record reports no health-based violations for this measured scope.
Home Safety Score
Average Home Safety Score for San Dimas: C (58/100)
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
San Dimas water systems draw from: Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0021 mg/L (EPA action level: 0.015 mg/L)
- 0 of 1 ZIP code with known status 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.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Stage 1 DBP Rule | Treatment Technique | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 91773 | C | 1 | 0 | Gswc-san Dimas |
All ZIP Codes in San Dimas
- 91773 [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
Reporting periods vary by source. Missing data is shown as unavailable, not as zero.
CDC Health Data for San Dimas
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 San Dimas
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is San Dimas's Housing Stock?
With 77% 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 San Dimas - median build year 1974 - 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 San Dimas 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.
San Dimas: Remediation Cost in Perspective
Property equity in San Dimas 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 San Dimas are relatively low compared to home values. The $1,200–$2,600 estimated range is a small fraction of median property value. Home values are 2% above the California average.
Protecting Children from Lead in San Dimas
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.
Pulling a tap sample fills the gap that utility data cannot close, particularly here where 77% of housing dates from the pre-rule era and citywide monitoring sits at or above the regulatory mark in San Dimas.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Historical Flood-Claim Evidence for San Dimas
Historical NFIP data for San Dimas contains 8 flood insurance claims. Among claims with payment data, the average reported building, contents, and ICC component sum is $1,710. Among ZIP codes with claim records, 0% have an A- or V-family dominant rated zone recorded in those historical claims. This is not a complete current FEMA property-map inventory.
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. The <strong>$1,800</strong> remediation estimate shown here excludes flood insurance and is not derived from NFIP claim count.
Claim count does not establish current property risk. Check the exact address in FEMA's current map and obtain a property-specific insurance quote when relevant.
Source: historical FEMA National Flood Insurance Program (NFIP) claim records. No current FEMA property-map designation is asserted.
What You Can Do in San Dimas
- 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 Stage 1 DBP Rule can reduce the most common contaminant found in San Dimas's water.
- Check your home's plumbing. With 77% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for San Dimas, CA