How much copper is in Eureka water?

The maximum detected level of copper in Eureka water is 940 ppb. The EPA limit is 1.3 mg/L (action level). See the ZIP code table above for area-specific levels.

Detected Copper

Copper in Eureka, CA Drinking Water

Q: Is copper in Eureka water safe?

Copper was detected in Eureka water at 940 ppb, below the EPA limit of 1.3 mg/L (action level). Check ZIP-level data on this page for your specific area.

Copper data for Eureka, California · 27,948 residents · 3 ZIP codes

In Eureka, California, Copper has been detected in the public water supply — a contaminant that health agencies track because of documented effects associated with prolonged exposure at elevated concentrations.

940 ppb

Max Level Detected

940 ppb

Average Level

1.3 mg/L (action level)

EPA action level

Moderate

Health Risk

Reverse Osmosis or NSF 53 Carbon Block

Best Filter Method

Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14

Copper in Eureka Tap Water

Copper has been detected in Eureka, California drinking water at a maximum level of 940 ppb — below the EPA action level of 1.3 mg/L (action level).

This analysis covers 27,948 residents across 3 ZIP codes in Eureka.

Eureka's overall water quality grade is A (90/100).

Is Copper in Eureka Water Safe?

Copper was detected in Eureka 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
95501	940 ppb	1.3 mg/L (action level)	OK
95502	940 ppb	1.3 mg/L (action level)	OK
95503	940 ppb	1.3 mg/L (action level)	OK

Average copper level across Eureka: 940 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 Eureka 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.

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