If you rely on a public water system in San Gabriel, California, Nitrate is a contaminant your utility has been required to test for — and EPA records show it has been detected at measurable levels, making it worth understanding as part of your tap water's detection record.

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

Nitrate in San Gabriel Tap Water

Nitrate has been detected in San Gabriel, California drinking water at a maximum level of 7.5 ppb — below the EPA MCL of 10 mg/L (as nitrogen).

This analysis covers 208,233 residents across 3 ZIP codes in San Gabriel.

San Gabriel's overall water quality grade is C (66/100).

Is Nitrate in San Gabriel Water Safe?

Nitrate was detected in San Gabriel 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 nitrate levels further.

Nitrate Levels by ZIP Code

Average nitrate level across San Gabriel: 7.5 ppb

Health Effects of Nitrate

• Methemoglobinemia ("blue baby syndrome") in infants under 6 months
• Increased risk of colorectal and bladder cancer (long-term)
• Thyroid disease from chronic exposure
• Possible reproductive effects

Health risk severity: High. Governed by the National Primary Drinking Water Regulations.

How Nitrate Gets Into Drinking Water

• Agricultural fertilizer runoff
• Animal feedlot operations and manure
• Septic system leachate
• Urban stormwater and wastewater discharge

What to Do About Nitrate in San Gabriel Water

1. Reverse osmosis is the most effective method for nitrate removal
2. Ion exchange systems designed for nitrate can also work
3. Standard carbon filters do NOT remove nitrate
4. Boiling water increases nitrate concentration — never boil for nitrate

Look for filters certified under NSF 53 / NSF 58 for nitrate removal.

Related

• Nitrate — National Overview
• Nitrate in California
• California Water Quality
• San Gabriel Water Quality
• Check Your ZIP Code