Nitrates are among the most commonly monitored contaminants in drinking water because elevated levels can present health concerns, particularly for infants. Although nitrates occur naturally in the environment, human activities such as agriculture, fertilizer use, and wastewater disposal can increase nitrate concentrations in groundwater and surface water.
This guide explains what nitrates are, where they come from, how they enter drinking water, current EPA standards, potential health considerations, testing recommendations, and practical ways homeowners can reduce exposure.
Looking for a countertop gravity-fed filtration system? The Big Berkey® Water Filter is our most popular stainless steel system for everyday household use.
What Are Nitrates?
Nitrates (NO3-) are naturally occurring compounds made up of nitrogen and oxygen. Nitrogen is an essential nutrient for plant growth and is part of the natural nitrogen cycle.
Because nitrates dissolve easily in water, they can move through soil into groundwater, rivers, lakes, and reservoirs that supply drinking water.
Nitrates should not be confused with nitrites (NO2-). Although related, they are different compounds with different drinking water standards.
Where Do Nitrates Come From?
Nitrates occur naturally as organic matter decomposes and nitrogen cycles through the environment. However, elevated nitrate levels often result from human activities.
Common sources include:
- Agricultural fertilizers
- Animal manure
- Septic systems
- Wastewater treatment
- Stormwater runoff
- Natural soil and plant decomposition
Because nitrates dissolve readily in water, they can travel considerable distances through groundwater before reaching wells or public water supplies.
How Do Nitrates Get Into Drinking Water?
Rainfall and irrigation water can carry nitrates through soil into underground aquifers. Surface runoff may also transport nitrates into rivers and lakes that serve as drinking water sources.
Private wells are often more vulnerable because they typically draw groundwater directly from local aquifers.
Who Is Most Likely to Have Elevated Nitrate Levels?
Higher nitrate concentrations are more commonly found in:
- Agricultural regions
- Areas with extensive fertilizer use
- Communities with numerous septic systems
- Shallow private wells
- Groundwater sources affected by runoff
Many public water systems routinely monitor nitrates, while private well owners are generally responsible for testing their own water.
Can You Taste, Smell, or See Nitrates?
No.
Nitrates have no reliable taste, odor, or color at drinking water concentrations. Water may appear perfectly clear while containing elevated nitrate levels.
Laboratory testing is the only dependable way to determine nitrate concentrations.
EPA Drinking Water Standard for Nitrates
The U.S. Environmental Protection Agency has established an enforceable Maximum Contaminant Level (MCL) of 10 milligrams per liter (mg/L) as nitrogen, often written as 10 mg/L nitrate-nitrogen (NO3-N).
Some laboratory reports instead list nitrate as the entire nitrate ion rather than nitrate-nitrogen. Understanding which measurement is being reported is important when comparing results.
Why Are Infants Especially Sensitive?
Infants younger than six months are particularly sensitive to elevated nitrate levels because their digestive systems can convert nitrate into nitrite more readily than older children and adults.
Nitrite can interfere with the blood's ability to carry oxygen, leading to a condition known as methemoglobinemia, sometimes called "blue baby syndrome."
For this reason, the EPA drinking water standard is designed to protect infants as well as the general population.
Should Private Well Owners Test for Nitrates?
Yes.
If your home uses a private well, periodic nitrate testing is recommended, especially if:
- You live near agricultural land.
- Your property uses a septic system.
- Your well is shallow.
- There are infants or pregnant women in the household.
- You have never tested your well.
Many state health departments recommend annual nitrate testing for private wells in agricultural areas.
How Can Homeowners Reduce Nitrate Exposure?
If you are concerned about nitrates in drinking water, consider these practical steps:
- Review your local Consumer Confidence Report (CCR).
- Test private wells regularly.
- Inspect nearby septic systems.
- Avoid excessive fertilizer application near wells.
- Use a point-of-use treatment system appropriate for nitrate reduction.
Can Boiling Remove Nitrates?
No.
Boiling water does not remove nitrates. Because water evaporates during boiling while dissolved nitrates remain, boiling may actually increase the nitrate concentration slightly.
Berkey® Water Filters and Nitrate Reduction
Berkey® countertop gravity-fed water filter systems are designed for everyday household use.
When equipped with Black Berkey® Replacement Filters, Berkey® systems are designed to reduce a broad range of unwanted contaminants.
If nitrate contamination is a specific concern, homeowners should review the most current Berkey performance information and determine whether additional treatment methods are appropriate for their particular water conditions.
For most households seeking everyday countertop filtration, the Big Berkey® Water Filter remains our most popular system.
Choosing the Right Berkey® System
| System | Capacity | Best For | Product |
|---|---|---|---|
| Travel Berkey® | 1.5 Gallons | Singles & Couples | View Product |
| Big Berkey® | 2.25 Gallons | Most Families | View Product |
| Royal Berkey® | 3.25 Gallons | Larger Families | View Product |
| Imperial Berkey® | 4.5 Gallons | High Daily Water Use | View Product |
| Crown Berkey® | 6 Gallons | Large Homes & Offices | View Product |
Frequently Asked Questions
What causes nitrates in drinking water?
Nitrates may occur naturally, but elevated levels often result from fertilizers, agricultural runoff, animal manure, septic systems, and wastewater.
Are nitrates harmful?
Elevated nitrate levels are of greatest concern for infants under six months of age because they may increase the risk of methemoglobinemia, also known as blue baby syndrome.
Can boiling remove nitrates?
No. Boiling does not remove nitrates and may slightly increase their concentration as water evaporates.
Should private well owners test for nitrates?
Yes. Regular testing is recommended, particularly in agricultural areas or where private wells may be affected by fertilizer or septic systems.
Can I taste nitrates?
No. Nitrates generally have no noticeable taste, odor, or appearance in drinking water.
Which Berkey® system is best for most families?
The Big Berkey® Water Filter is our most popular countertop gravity-fed system because it offers an excellent balance of capacity and convenience.
Where can I buy replacement filters?
You can shop genuine replacement elements and accessories on our Berkey® Replacement Filters page.
Final Thoughts
Nitrates are one of the most important drinking water contaminants for private well owners and families living in agricultural regions. Because they cannot be detected by taste, smell, or appearance, routine testing remains the best way to understand your household's water quality.
If you are evaluating point-of-use filtration for everyday drinking water, the Big Berkey® Water Filter offers a convenient, gravity-fed countertop solution for many households. Understanding your local water quality and reviewing current filtration performance information will help you choose the approach that best fits your home's needs.