San Luis Obispo County, California
34 ZIP codes · Avg score 77/100 · Grade B · Updated
ZipCheckup grade for San Luis Obispo County: B.
This ZIP looks solid, with a few items worth a quick check.
Unlike many counties its size, San Luis Obispo County keeps violation rates low - all 34 ZIP codes score at or above the state average for tap water safety, with no systemic concerns flagged in the current data set.
How San Luis Obispo County Compares
How San Luis Obispo County Compares
San Luis Obispo County scores 1 points above the California state average (76/100) and 4 points above the national average (73/100).
Data: ZipCheckup Home Safety Score model 4.0.0; EPA SDWIS, UCMR 5, EPA radon zones, EPA AirData Last verified:
ZIP Code Risk Map
Water Quality Map: San Luis Obispo County, California
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 11.3 (asthma 9.9%, diabetes 10%)
Estimated additional annual cost per homeowner: $1,246, driven primarily by flood
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across San Luis Obispo County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 20 violations. Past 5 years: 68 total (68 health-based). Health-based violations are rising versus the prior 2-year window - worth closer monitoring.
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Modeled area-level indicator, not a failure probability. Sources: Census ACS housing age, EPA DWINS infrastructure needs, EPA SDWIS violations, and EPA lead indicators.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,246
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Water Safety Affordability
How much it costs to fix water issues relative to home values in San Luis Obispo County
Remediation costs are relatively manageable for most homeowners in San Luis Obispo County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for San Luis Obispo County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving San Luis Obispo County
8 community water systems serving San Luis Obispo County.
- B
- C
- B
- B
- B
- B
Show all 8 water systems
- B
- B
33 total water systems serve San Luis Obispo County.
Systems with the most violations in San Luis Obispo County
5 water systems with recorded EPA violations.
- B
- B
- C
- B
- B
All ZIP Codes in San Luis Obispo County
34 ZIP codes tracked in San Luis Obispo County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 93401 | San Luis Obispo | 83 | B | 1 (1 health) | $944K |
| 2 | 93405 | San Luis Obispo | 83 | B | 0 | $898K |
| 3 | 93409 | San Luis Obispo | 83 | B | 1 | — |
| 4 | 93428 | Cambria | 83 | B | 1 (1 health) | $870K |
| 5 | 93433 | Grover Beach | 83 | B | 0 | $692K |
| 6 | 93442 | Morro Bay | 83 | B | 1 (1 health) | $871K |
| 7 | 93444 | Nipomo | 83 | B | 13 (12 health) | $746K |
| 8 | 93465 | Templeton | 83 | B | 0 | $875K |
| 9 | 93449 | Pismo Beach | 81 | B | 4 (3 health) | $993K |
| 10 | 93445 | Oceano | 78 | B | 37 (13 health) | $538K |
| 11 | 93402 | Los Osos | 67 | C | 0 | $729K |
| 12 | 93422 | Atascadero | 67 | C | 0 | $692K |
| 13 | 93420 | Arroyo Grande | 62 | C | 37 (13 health) | $872K |
| 14 | 93446 | Paso Robles | 59 | C | 12 (12 health) | $661K |
| 15 | 93403 | San Luis Obispo | — | — | — | |
| 16 | 93406 | San Luis Obispo | — | — | — | |
| 17 | 93407 | San Luis Obispo | — | — | 0 | — |
| 18 | 93408 | San Luis Obispo | — | — | — | |
| 19 | 93410 | San Luis Obispo | — | — | 0 | — |
| 20 | 93412 | Los Osos | — | — | — | |
| 21 | 93421 | Arroyo Grande | — | — | — | |
| 22 | 93423 | Atascadero | — | — | — | |
| 23 | 93424 | Avila Beach | — | — | 0 | $1180K |
| 24 | 93430 | Cayucos | — | — | 0 | $965K |
| 25 | 93432 | Creston | — | — | 0 | $900K |
| 26 | 93435 | Harmony | — | — | — | |
| 27 | 93443 | Morro Bay | — | — | — | |
| 28 | 93447 | Paso Robles | — | — | — | |
| 29 | 93448 | Pismo Beach | — | — | — | |
| 30 | 93452 | San Simeon | — | — | $277K | |
| 31 | 93453 | Santa Margarita | — | — | 0 | $720K |
| 32 | 93461 | Shandon | — | — | $455K | |
| 33 | 93475 | Oceano | — | — | — | |
| 34 | 93483 | Grover Beach | — | — | — |
Recommended Buyer Guides for San Luis Obispo County
Strictly editorial - no paid placements influence which guides appear; the selection draws on NSF certifications and EPA detection records for water systems serving this county.
- Best Water Filters for Lead — Lead above EPA action level in 1 ZIP code
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for San Luis Obispo County, California
Overview
San Luis Obispo County in California covers 34 tracked ZIP records with an average Home Safety Score of B (77/100) across 14 scored records.
9 of 20 ZIP codes with a reported violation count in the available EPA record have recorded EPA violations. 31 health-based violations appear in the available health breakdown.
← Back to California Home Safety Profile
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- PFAS screening: EPA UCMR 5
- Radon zones: EPA Map of Radon Zones
- Air quality: EPA AirData annual AQI
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Reporting periods vary by source. Missing data is shown as unavailable, not as zero.