Los Alamos, CA: High Radon Risk — 70/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
Public water monitoring in Los Alamos shows a safety record well above the CA median — health-based violations are isolated exceptions rather than recurring patterns, the city's systems have stayed compliant across recent reporting cycles, and no cluster of recurring exceedances appears in any single service area.
How Los Alamos Compares
Data: EPA SDWIS Last verified: 2026-06-03
Los Alamos Water: The Quick Version
- Average lead level: 0.0014 mg/L.
- Homes built before 1986: 41% — older plumbing may contain lead solder.
- Estimated remediation: $2,400 per household.
- CDC health risk index: 10.9.
Water Systems Serving Los Alamos
Across Los Alamos, CA, residential water comes from 3 primary utilities rather than a single consolidated provider. Each system operates independently — managing its own distribution infrastructure, rate schedules, and EPA compliance filings. Federal records track 3 water systems in the area, with these top providers accounting for the majority of residential connections.
Overview
We track water quality and home safety data for 1 ZIP code in Los Alamos, California (population ~896), covering 3 community water systems serving approximately 5,249 people region-wide.
No EPA violations recorded across any ZIP codes in Los Alamos — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Los Alamos: B (70/100)
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
Los Alamos water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0014 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 93440 | B | Mission Hills Csd | 3,600 |
All ZIP Codes in Los Alamos
- 93440 [B]
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 Los Alamos
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
How Old Is Los Alamos's Housing Stock?
With 41% 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
When trying to understand water quality at the household level, the year a home was built often matters more than any city-wide water report. That's because the 1986 federal ban on lead solder in plumbing, and the earlier phase-out of lead pipes before 1970, created sharp discontinuities in residential plumbing risk by construction era. Los Alamos's median build year of 1980 puts the city in the transition zone: a substantial share of the housing stock postdates the solder ban, but a comparable fraction predates it — with the oldest homes carrying both the solder risk and the pipe risk simultaneously. Whether any individual household sits on the safer or riskier side of these thresholds is the key question, and it's one the city-wide median alone can't answer.
Most homes in Los Alamos were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
Los Alamos: Remediation Cost in Perspective
In Los Alamos, property wealth outpaces what documented remediation typically demands — the equity burden lands well within the low tier.
Remediation costs in Los Alamos are relatively low compared to home values. The $1,600–$3,300 estimated range is a small fraction of median property value. Home values are 9% below the California average.
Protecting Children from Lead in Los Alamos
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.
Despite citywide averages serving as the standard public reference point, those aggregates cannot resolve what is happening at one specific faucet — and where 41% of Los Alamos homes come from before the solder rule or where utility samples sit at or above the action mark, the gap between system data and faucet reality matters more than it does in lower-exposure communities. An in-home draw closes that gap, with certified filtration through retailer networks available 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 Los Alamos
100% of ZIP codes in Los Alamos are mapped into FEMA-designated flood zones, and the NFIP records 3 claims reflecting a multi-event flood history. That combination places local flood exposure in the range where water-quality implications deserve at least periodic attention.
Los Alamos has a moderate flood history with 3 FEMA claims averaging $3,724 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 Los Alamos, CA