Los Osos Community Services District
EPA ID: CA4010016 · 7,086 people served · 1 ZIP code
ZipCheckup's reading of EPA SDWIS for Los Osos Community Services District (CA4010016): PFAS sampling above the current EPA limit (UCMR5). Zero EPA violations over five years - Los Osos Community Services District has kept tap water compliance clean for its full service population of 7,086.
Data: EPA SDWIS
Service Area Map
Coverage area for Los Osos Community Services District Source: EPA SDWIS service area boundaries.
Service area boundary - Grade C
Service Area Demographics
The Los Osos Community Services District serves a community with a median household income of $103,839 and an estimated 15,085 residents across its service area. Approximately 80% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Los Osos Community Services District's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
Infrastructure Risk
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 8 detections recorded. 2 exceed federal EPA limits (4 ppt for PFOA/PFOS). 2 exceed state limits.
Comparable Water Systems
Similar-sized systems in California
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Los Osos Community Services District (EPA ID: CA4010016) is a community water system in California that serves approximately 7,086 people from groundwater sources.
This system serves ZIP code 93402 in Los Osos.
ZIP-Area Home Safety Context: C (67/100)
This is the average Home Safety Score for 1 of 1 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.
Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.0011 mg/L | No | N/A |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by CA or modeled from parcel and building-footprint data.
- 93402 - Los Osos
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Los Osos Community Services District (CA4010016) on EPA.gov.
Frequently Asked Questions
Is Los Osos Community Services District water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Los Osos Community Services District in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
How many people does Los Osos Community Services District serve?
Los Osos Community Services District serves approximately 7,086 people across 1 ZIP code in California.
Where does Los Osos Community Services District get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: Above Current MCL
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). One or more PFAS compounds were measured above the current state-enforceable MCL.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Los Osos Community Services District Water Report, CA. https://zipcheckup.com/water-system/ca4010016/
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title = {{Los Osos Community Services District Water Report, CA}},
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url = {https://zipcheckup.com/water-system/ca4010016/}
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What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Los Osos Community Services District (EPA ID: CA4010016) - request the latest Consumer Confidence Report or ask about specific contaminants.