Los Osos, CA Water Safety: 81/100 (2026)
2 ZIP codes · 3 water systems · Updated 2026-06-03
Unlike many cities its size in CA, Los Osos keeps health-based violation rates low — systems here score at or above the state average for tap water safety, with no systemic concerns flagged in the current data set.
How Los Osos Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Los Osos Water
- Average lead level: 0.0051 mg/L.
- Estimated remediation: $1,300 per household.
- CDC health risk index: 11.26.
Who Supplies Your Water in Los Osos
Residential water service in Los Osos, CA is divided among 3 separate utilities, drawn from 3 systems on file with federal regulators.
Overview
We track water quality and home safety data for 2 ZIP codes in Los Osos, California, covering 3 community water systems serving approximately 15,085 people.
No EPA violations recorded across any ZIP codes in Los Osos — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Los Osos: B (81/100)
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 Osos water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0051 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)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 2 ZIP codes
- Zone 3 (Low): 0 ZIP codes
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 93402 | B | Los Osos Community Services District | 7,086 |
| 93412 | B | Los Osos Community Services District | 7,086 |
All ZIP Codes in Los Osos
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.
Health Outcomes in Los Osos
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
Cost Context: What Remediation Means for Los Osos Homeowners
When estimated remediation is placed alongside median property values in Los Osos, the resulting ratio is low — a finding consistent with a household financial perspective where documented issues can be addressed without a meaningful impact on overall equity position, making this market one of the more favorable contexts for remediation planning.
Remediation costs in Los Osos are relatively low compared to home values. The $600–$2,100 estimated range is a small fraction of median property value. Home values are 1% below the California average.
Lead Exposure Risk for Children in Los Osos
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.
Lead risk in Los Osos appears low overall, but individual homes may differ. Testing is the only way to confirm your water's lead content.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Los Osos
Taken together, Los Osos's 14 NFIP flood insurance claims and 50% FEMA flood zone coverage place it in the moderate range of exposure. That middle position has specific implications for water quality. The contamination pathways that flooding can open — surface water overwhelming treatment facility intake, floodwaters infiltrating private wells, distribution pressure changes creating backflow — are not constant risks in a moderate-exposure community. But they do become active during significant flood events, and the claim record here indicates enough of those events to make flood timing an occasional factor in local water quality conversations.
Los Osos has a moderate flood history with 14 FEMA claims averaging $7,431 per payout. 50% 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>$1,300</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 Osos, CA