Nitrate CA

Nitrate in Drinking Water — Presidio of San Francisc...

Presidio of San Francisco · San Francisco, CA · 3,500 people served

7.48 mg/L

Highest Level Detected

10 mg/L (as nitrogen)

EPA Limit

High

Health Risk Level

ZIP Codes Served

3,500

People Served

Reverse Osmosis or Ion Exchange

Best Filter Method

Data: EPA SDWIS, ECHO, 2021 Consumer Confidence Report

Medical Disclaimer: This page provides environmental data and general health information from EPA and CDC sources. It is not medical advice. If you have health concerns related to your drinking water, consult a healthcare provider.

Nitrate Detected in Presidio of San Francisco

Nitrate was detected at 7.48 mg/L in the Presidio of San Francisco water system serving San Francisco (CA), approaching the EPA limit of 10 mg/L (as nitrogen).

This system serves approximately 3,500 people across 33 ZIP codes.

Data source: 2021 Consumer Confidence Report (CCR) and EPA SDWIS/ECHO.

Detected Levels

Contaminant	Level Detected	EPA Limit	Status
Nitrate as N	7.48 mg/L	10 mg/L	Within Limit

Health Effects of Nitrate

Nitrate above 10 mg/L is acutely dangerous for infants under 6 months old, causing methemoglobinemia ("blue baby syndrome") — a condition where nitrate reduces the blood's ability to carry oxygen. Symptoms include bluish skin, shortness of breath, and in severe cases, death. In adults, long-term nitrate exposure is associated with increased risk of colorectal cancer, thyroid disease, and neural tube birth defects. Agricultural runoff is the primary source of nitrate contamination.

Source: CDC — Nitrate and Drinking Water from Private Wells; EPA.

EPA Standard

The EPA maximum contaminant level (MCL) for nitrate is 10 mg/L (as nitrogen), governed by the National Primary Drinking Water Regulations. Water systems that exceed this limit must notify consumers and take corrective action.

What You Can Do

If you have an infant, do NOT use tap water for formula preparation if nitrate exceeds 10 mg/L
Install a reverse osmosis system — the most effective household nitrate removal method
Ion exchange filters are also effective for nitrate removal
Do NOT boil water to remove nitrate — boiling concentrates it and makes it worse
Standard carbon filters and water softeners do NOT remove nitrate
If on a private well near agricultural land, test at least annually

Recommended Water Filters

The most effective treatment for nitrate removal is Reverse Osmosis or Ion Exchange.

Filter Type	Effectiveness	NSF Standard	Notes
Reverse Osmosis (RO)	90-95%	NSF 58	Most reliable home treatment for nitrate
Ion Exchange	90-95%	NSF 53	Effective but may release other ions; requires regular regeneration
Distillation	95%+	NSF 62	Effective but slow and energy-intensive

ZIP Codes Served by This System

Check water quality for your specific ZIP code:

Related Resources

Detected Levels

Contaminant	Level Detected	EPA Limit	Status
Nitrate as N	7.48 mg/L	10 mg/L	Within Limit

Recommended Water Filters

The most effective treatment for nitrate removal is Reverse Osmosis or Ion Exchange.

Filter Type	Effectiveness	NSF Standard	Notes
Reverse Osmosis (RO)	90-95%	NSF 58	Most reliable home treatment for nitrate
Ion Exchange	90-95%	NSF 53	Effective but may release other ions; requires regular regeneration
Distillation	95%+	NSF 62	Effective but slow and energy-intensive

ZIP Codes Served by This System

94101 94119 94120 94125 94126 94128 94129 94136 94137 94139 94140 94141 94142 94143 94144 94145 94146 94147 94150 94151 +13 more

Full Water System Profile: See all contaminants, violations, and lead levels for Presidio of San Francisco.

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