Cucamonga Valley Water District Water Quality — Rancho Cucamonga, California
PWSID CA3610018 · Surface waterMunicipal
211,069 people served. No health-based SDWIS violations recorded in the past 5 years.
Active signals
No SDWIS health-based or unresolved violations on the record. Contaminant detail and equity context below.
What's On The SDWIS Record
Health-based violations exceed an MCL or treatment-technique standard. Monitoring violations are reporting failures with no measured exceedance — they tell you the system isn't fully transparent, not that the water is unsafe today.
No SDWIS violations recorded in the analysis window.
Who Drinks This Water
Rancho Cucamonga, California (Census place; block-group disparity scores aggregated by centroid containment): a service population of 174,696. Local disparity score for pm2.5 (fine particulate) sits moderately above the reference (144). Why we surface this →
Low-income
People of color
Under age 5
Over age 64
- PM2.5 (fine particulate)Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.95in the highest 10% nationally
- OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.100in the highest 5% nationally
- Nitrogen dioxide (NO₂)Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.82in the highest 20% nationally
- Diesel particulateHealth riskSoot from diesel engines (trucks, trains, ports, construction). EPA classifies it as a likely human carcinogen and a major driver of childhood asthma near freight corridors.91in the highest 10% nationally
- Toxic releases (RSEI)Health riskEPA's Risk-Screening Environmental Indicators score — weights TRI chemical releases by toxicity, where they go, and how many people are nearby. Higher means greater modeled cancer and chronic-health risk.79above the national median
- Traffic proximityHealth riskPopulation-weighted distance to high-volume roads. Living close to heavy traffic raises exposure to PM2.5, NO₂, and diesel exhaust — and the cardiovascular and asthma risks that follow.88in the highest 20% nationally
- Lead-paint risk (pre-1960 housing)Health riskShare of housing built before 1960, when lead-based paint was common. Dust from deteriorating paint is the leading cause of childhood lead poisoning, which permanently impairs cognitive development.30below the national median
- Superfund site proximityHealth riskPopulation-weighted distance to NPL Superfund sites — the most contaminated waste sites in the country. Nearby groundwater, soil, and air can carry industrial solvents, metals, and other long-lived contaminants.56near the national median
- RMP-facility proximityHealth riskDistance to facilities holding chemicals at quantities large enough to require an EPA Risk Management Plan (refineries, fertilizer plants, etc.). These pose acute exposure risk during accidental releases.89in the highest 20% nationally
- Hazardous-waste site proximityHealth riskDistance to RCRA hazardous-waste handlers (treatment, storage, disposal facilities). Indicates potential exposure to industrial chemicals in air, soil, and groundwater.92in the highest 10% nationally
- Underground storage tanksHealth riskDensity of underground tanks (gasoline, heating oil, industrial fluids). Leaking tanks are a leading source of benzene and other volatile organic compounds in groundwater drinking-water supplies.28below the national median
- NPDES wastewater proximityHealth riskDistance to permitted industrial wastewater dischargers. Closer proximity raises exposure to pollutants released into surface waters used for fishing, recreation, and downstream drinking-water intakes.19below the national median
- Drinking-water non-complianceHealth riskEPA score for public water systems with health-based Safe Drinking Water Act violations. Higher means more residents on systems that recently exceeded safe limits for contaminants like lead, arsenic, or nitrate.76above the national median
| Indicator | Disparity score | Reading |
|---|---|---|
| PM2.5 (fine particulate) | 144 | moderately above the reference |
| Ozone | 150 | well above the reference burden |
| Nitrogen dioxide (NO₂) | 121 | moderately above the reference |
| Diesel particulate | 137 | moderately above the reference |
| Toxic releases (RSEI) | 108 | near the reference |
| Traffic proximity | 132 | moderately above the reference |
| Lead-paint risk (pre-1960 housing) | 24 | well below the reference |
| Superfund site proximity | 15 | well below the reference |
| RMP-facility proximity | 131 | moderately above the reference |
| Hazardous-waste site proximity | 137 | moderately above the reference |
| Underground storage tanks | 0 | well below the reference |
| NPDES wastewater proximity | 27 | well below the reference |
| Drinking-water non-compliance | 0 | well below the reference |
Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).
Source. EPA Safe Drinking Water Information System · retrieved 2026-05-07. Reporting period 2021-01-01 → 2026-05-07.
What this is not. SDWIS records compliance against federal MCLs — not a direct readout of tap-water concentrations. Active health-based violations are not the same as a current crisis; we link to the EPA record so you can verify return-to-compliance status before forming a conclusion.