Blog

What Is Nitrate Pollution?

Alex Peska
Algal bloom - credit Getty Images

Nitrate Watch is the latest initiative in the Izaak Walton League’s campaign to address environmental pollution and degradation. As with many environmental pollutants, nitrates significantly threaten the health of ecosystems and the humans residing near them. Therefore, it is essential to monitor nitrate levels in local waterways in order to prevent harm to all forms of life.

Nitrate (NO3) is a naturally occurring compound of nitrogen and oxygen. An essential component of life on Earth, nitrate’s constituent element, nitrogen, is needed in large quantities by all organisms. Nitrogen is utilized in everything from DNA replication to capturing sunlight for energy production in plants. Without usable nitrogen, the Earth could not support the billions of people now living on our planet.

The Green Revolution of the early 20th century introduced a radical new innovation: chemical fertilizers. These fertilizers essentially injected the earth with nutrients, ready to be utilized by plants. How are these fertilizers made, and how do they work? Laboratory processes allow for nitrogen to be taken from the air, where it is not usable by plants, and converted into a solid or liquid form that plants can absorb through their roots.

A U.S. EPA study concluded that 41 percent of streams and 46 percent of rivers that were part of a 2008-2009 survey were impaired because of excessive nitrogen and phosphorus inputs.

Industrialist nations like the United States sought to increase crop yields, lower costs, and provide healthier foods to the rest of the world through industrial farming. These techniques were highly effective. Anthropogenic production of nitrogen has increased over six-fold since 1940 in the U.S. Consequently, the annual flow of nitrogen to the oceans has nearly doubled from background conditions.

While fertilizers have allowed for unprecedented crop production, they are far from perfect. When applied in excess or at the improper time, not all the nutrients will be used up by the plants. Through the process of runoff, the extra fertilizer is picked up by rainwater and carried to the nearest body of water, where it collects.

It is estimated that about 80 percent of nitrogen fertilizer is lost from the fields where it is applied. A U.S. EPA study concluded that 41 percent of streams and 46 percent of rivers that were part of a 2008-2009 survey were impaired because of excessive nitrogen and phosphorus inputs. It is estimated that about half of nitrogen pollution originates from agriculture, while additional sources of runoff include human wastewater from septic tanks and animal waste.

The total cost of environmental and health damages related to anthropogenic nitrogen pollution in the early 2000s was estimated at $210 billion a year in the United States.

The effects of nitrate runoff and subsequent pollution vary greatly. The most significant results include cyanobacterial harmful algal blooms (CHABs), which can lead to the collapse of a waterway’s biological system. (Learn how.) Nitrate pollution also causes human health effects, with links to blue baby syndrome and endocrine disruptions through the release of toxins. This issue threatens not only the health of the natural world, but the health of humans as well.

There are also economic impacts related to the handling of nitrates. Conservative annual cost estimates for management related to CHABs stand at about $2.4 billion, just in U.S. lake and stream systems. These costs are related to loss of property value, the need for bottled drinking water, loss of recreation opportunities, costs of protecting species, and threats to public health.For example, in 2015, the Des Moines Water Works sued three Iowa drainage districts after being forced to spend $1 million to treat water with excess nitrate pollution. In fact, the total cost of environmental and health damages related to anthropogenic nitrogen pollution in the early 2000s was estimated at $210 billion a year in the United States. Unfortunately, marginalized communities like low-income households and immigrants often suffer a larger share of these effects.

Responsible nitrate management is beneficial to everyone. Local residents can enjoy a healthier life, our ecosystems can remain active and clean, and farmers can spend less on producing crops. That is why the Izaak Walton League is inviting you to become an active participant in creating a community that is free of nitrate pollution. By adopting the pledge, participating in at-home water testing, and writing to local policymakers, you will be taking steps to ensure nitrate pollution can be effectively controlled. Simply educating yourself and others is a great first step!

Get started with Nitrate Watch

Alex Peska is the Izaak Walton League's 2022 Nitrate Watch intern.