Data: EPA SDWIS, ECHO, 2011 Consumer Confidence Report

Nitrate Detected in Orosi Public Utility District

Nitrate was detected at 23 mg/L in the Orosi Public Utility District water system serving Orosi (CA), exceeding the EPA limit of 10 mg/L (as nitrogen).

This system serves approximately 8,300 people across 1 ZIP code.

Data source: 2011 Consumer Confidence Report (CCR) and EPA SDWIS/ECHO.

Detected Levels

Contaminant	Level Detected	EPA Limit	Status
Nitrate as NO3	23 ppm	45 ppm	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:

• 93647

Related Resources

• Orosi Public Utility District — Full Water System Profile
• Nitrate in Drinking Water — Overview
• EPA: Nitrate