If you rely on a public water system in South Pasadena, 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: 2026-04-05

Nitrate in South Pasadena Tap Water

Nitrate has been detected in South Pasadena, California drinking water at a maximum level of 45 ppb — below the EPA MCL of 10 mg/L (as nitrogen).

This analysis covers 26,297 residents across 2 ZIP codes in South Pasadena.

South Pasadena's overall water quality grade is B (81/100).

Is Nitrate in South Pasadena Water Safe?

If you live in an affected ZIP code, consider installing a reverse osmosis or ion exchange filter certified under NSF 53 / NSF 58 and testing your water independently.

Nitrate Levels by ZIP Code

Average nitrate level across South Pasadena: 45 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 South Pasadena 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
• California Water Quality
• South Pasadena Water Quality
• Check Your ZIP Code