Riverdale, CA: 1 Health Violation — 77/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
Riverdale tap water earns a high safety grade — above-average compliance with CA and federal standards.
How Riverdale Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Riverdale Residents
- Your city's water systems recorded 1 violation in the past 5 years.
- Average lead level: 0.0057 mg/L.
- Homes built before 1986: 73% — older plumbing may contain lead solder.
- Estimated remediation: $2,500 per household.
- CDC health risk index: 12.33 — above typical levels.
Riverdale's Water Providers
Residential water in Riverdale, CA is supplied by 3 separate utilities — not one centralized authority. Each of those providers operates under its own service territory boundary, maintains its own distribution infrastructure, and files compliance documentation with the EPA on its own timeline. Federal data counts 3 water systems in the area, with these providers collectively accounting for the dominant share of household connections.
Overview
We track water quality and home safety data for 1 ZIP code in Riverdale, California (population ~6,224), covering 3 community water systems serving approximately 17,836 people region-wide.
1 of 1 ZIP code (100%) have recorded EPA violations. 1 health-based violation documented.
Home Safety Score
Average Home Safety Score for Riverdale: B (77/100)
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
Riverdale water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0057 mg/L (EPA action level: 0.015 mg/L)
- 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.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Nickel | Inorganic | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 93656 | B | 1 | 1 | Riverdale Public Utility District |
All ZIP Codes in Riverdale
- 93656 [B] — 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
Updated daily.
Riverdale Community Health Snapshot
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
What's in Riverdale's Water?
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Riverdale Infrastructure Age
With 73% 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
The lead that enters tap water in older homes often comes not from the municipal supply but from the home's own plumbing — from solder used in copper joints before the 1986 federal ban, or from lead pipes installed before 1970. In Riverdale, where the median build year is 1974, these older materials are widespread. More than half the residential stock predates the 1986 solder ban, and a significant fraction predates 1970 as well. For residents in those homes, the city-wide water quality picture is a less relevant frame than the specific materials inside their own walls and under their own street.
Over half of homes in Riverdale 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.
How Remediation Costs Compare in Riverdale
When remediation costs are measured against Riverdale home values, the resulting ratio is in the low tier — addressing documented water and safety issues here claims only a minor fraction of typical equity, and most homeowners are in a position where the financial commitment is straightforward rather than a material burden on their household budget.
Remediation costs in Riverdale are relatively low compared to home values. The $1,350–$3,900 estimated range is a small fraction of median property value. Home values are 63% below the California average.
Riverdale: Lead Risk & Vulnerable Populations
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.
Wherever 73% of local housing was built before solder rules changed — as is the case in Riverdale — a faucet-level sample closes the gap that aggregate utility data cannot.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Riverdale: Flood History & Water Damage Risk
Flood history in Riverdale spans 1 NFIP claim and 100% flood zone coverage — enough to place it in moderate-exposure territory where flood events are genuinely recurring rather than statistical outliers. That distinction matters for water quality assessment because the connection between flooding and water safety is not uniform across communities. In low-exposure areas, flooding rarely generates the conditions needed to compromise treatment or distribution infrastructure. In high-exposure areas, it can do so repeatedly. Moderate-exposure communities sit in between: flood events occur with enough frequency to make periodic infrastructure stress a reasonable concern, particularly for private well owners and residents in lower-elevation FEMA-designated zones.
Riverdale 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>$2,500</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 Riverdale, CA