Radium in San Pedro, CA Drinking Water
Radium data for San Pedro, California · 3,875,566 residents · 4 ZIP codes
For residents of San Pedro, California, Radium has appeared in public water supply sampling data.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14
Radium in San Pedro Tap Water
Radium has been detected in San Pedro, California drinking water at a maximum level of 8 pCi/L — 1.6x the EPA MCL.
This analysis covers 3,875,566 residents across 4 ZIP codes in San Pedro.
San Pedro's overall water quality grade is C (58/100).
Is Radium in San Pedro Water Safe?
Radium was detected in San Pedro water but currently falls within EPA limits. However, some health organizations argue the EPA MCL may not be protective enough.
If you are concerned, a reverse osmosis or ion exchange filter can reduce radium levels further.
Radium Levels by ZIP Code
| ZIP Code | Radium Level | EPA Limit | Status |
|---|---|---|---|
| 90731 | 8 pCi/L | 5 pCi/L (combined Ra-226 + Ra-228) | Exceeds limit |
| 90732 | 8 pCi/L | 5 pCi/L (combined Ra-226 + Ra-228) | Exceeds limit |
| 90733 | 8 pCi/L | 5 pCi/L (combined Ra-226 + Ra-228) | Exceeds limit |
| 90734 | 8 pCi/L | 5 pCi/L (combined Ra-226 + Ra-228) | Exceeds limit |
Average radium level across San Pedro: 8 pCi/L
Health Effects of Radium
- Increased risk of bone cancer (radium accumulates in bones)
- The body treats radium like calcium, storing it in bones
- Lifetime cancer risk of ~1 in 10,000 at 5 pCi/L
- No safe threshold for radioactive contamination
Health risk severity: High. Governed by the Radionuclides Rule.
How Radium Gets Into Drinking Water
- Natural radioactive decay in underground rock formations
- Groundwater sources (especially deep wells)
- Mining and industrial waste
- Higher in regions with specific geology (Midwest, parts of South)
What to Do About Radium in San Pedro Water
- Reverse osmosis (NSF 58 certified) removes 90%+ of radium
- Ion exchange (water softeners) can reduce radium
- Point-of-use RO at kitchen tap is most cost-effective
- GAC filters alone are NOT effective for radium
Look for filters certified under NSF 58 for radium removal.