Copper in Los Osos, CA Drinking Water
Copper data for Los Osos, California · 7,677 residents · 2 ZIP codes
Copper is regulated under the Safe Drinking Water Act because of its potential health effects at elevated concentrations; for residents of Los Osos, California, the relevant fact is that it has shown up in recent EPA compliance samples — point-of-use filtration is one option residents research, alongside reviewing the utility's published treatment data.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14
Copper in Los Osos Tap Water
Copper has been detected in Los Osos, California drinking water at a maximum level of 0.86 ppb — below the EPA action level of 1.3 mg/L (action level).
This analysis covers 7,677 residents across 2 ZIP codes in Los Osos.
Los Osos's overall water quality grade is B (81/100).
Is Copper in Los Osos Water Safe?
Copper was detected in Los Osos water but currently falls within EPA limits. However, some health organizations argue the EPA action level may not be protective enough.
If you are concerned, a reverse osmosis or nsf 53 carbon block filter can reduce copper levels further.
Copper Levels by ZIP Code
| ZIP Code | Copper Level | EPA Limit | Status |
|---|---|---|---|
| 93402 | 0.86 ppm | 1.3 mg/L (action level) | OK |
| 93412 | 0.86 ppm | 1.3 mg/L (action level) | OK |
Average copper level across Los Osos: 0.86 ppb
Health Effects of Copper
- Nausea, vomiting, and diarrhea (short-term, high levels)
- Liver and kidney damage (long-term)
- Particularly dangerous for people with Wilson's disease
- Infants are more sensitive than adults
Health risk severity: Moderate. Governed by the Lead and Copper Rule.
How Copper Gets Into Drinking Water
- Corrosion of copper household plumbing
- Acidic (low pH) water accelerates copper leaching
- New copper pipes leach more than aged ones
- Mining and industrial discharge (rare for tap water)
What to Do About Copper in Los Osos Water
- Run water for 30-60 seconds before use (flushes stagnant water)
- Install an NSF 53 or NSF 58 certified filter
- If pH is low, consider a whole-home acid neutralizer
- Test first-draw morning water to check actual copper levels
Look for filters certified under NSF 53 for copper removal.