Nitrate Watch

Men discussing sustainable agriculture

Nitrate (NO3-) is a naturally occurring compound made up of nitrogen and oxygen. Nitrogen is an essential nutrient for plant growth, but human activities produce more nitrogen than natural systems can use.

Fertilizers, manure and sewage all add extra nitrogen to the landscape. As this nitrogen moves through the environment, it becomes nitrate. The nitrate can then make its way to streams and sources of drinking water via surface runoff or groundwater saturation. Excess nitrate in water can pose serious problems for the health of humans and the environment.

You can help.

Take the Nitrate Watch Pledge and we will send you a FREE kit containing everything you need to measure nitrate in your drinking water or local waterways. See what's in the kit.

NOTE: Our supply of free Nitrate Watch kits for individuals outside of Iowa has been disbursed.

If you are in Iowa: feel free to request a kit – thanks to some Iowa-specific funding, we have kits available specifically for Iowa residents.

If you are outside of Iowa: you may complete this form and be added to a waitlist.

Interested in becoming a Nitrate Watch partner organization? Email

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Visit our Help page.

Coming Soon: Nitrate Watch!

This simple volunteer science project will help you see whether nitrate is polluting your waterways and creating health risks in your community. Join Nitrate Watch now and be the first to know when free test kits are available!

Nitrate Watch Story Map

Story map introduction Continue reading
Nitrate Watch annual report

2023 Annual Report

The annual report for Nitrate Watch’s inaugural season is available to view. This report summarizes participation and engagement in the program in 2023. We analyze the results reported by volunteers across the United States, and we zoom in on regions reporting a high volume of data. Click the image to view the highlights.

Read the complete annual report

Special Thanks to Our Funders

The Izaak Walton League of America has an application pending with the U.S. Patent and Trademark Office to register Nitrate Watch.

Nitrate Watch is a trademark of the Izaak Walton League of America.