With more than 30 years’ experience in the residential and commercial water treatment space, Mark Nelson is a Class 1 Drinking-Water Operator and a CBWA (Canadian Bottled Water Association) Certified Plant Operator. As founder and president of Nelson Water in Ottawa, Mark focuses on dealing with challenging water treatment system designs for problem water. He also heads the largest water bottling plant in the city of Ottawa with a delivery network throughout the Valley.

It’s important to preface this article with the statement that nitrogen is an element that is vital for every living thing on our planet. Nitrogen is needed to produce vital biomolecules that are used to create proteins and various other building blocks that are necessary for life to exist. But, when there is a high concentration of nitrogen present in water it can lead to a wide variety of water quality issues and some of them are a threat to our health. In this article, we will take a look at nitrite, we will explain how it can contaminate water and how you can remove it from your water supply.

What is Nitrite?

Nitrite is a naturally occurring form of nitrogen that is present in our environment. When nitrites are exposed to bacteria, they can be converted to nitrates, ammonium, and other forms. These various forms of nitrogen are an essential nutrient for plant life and that’s why many chemical fertilizers have nitrates as the main ingredient.

How Can Nitrites Contaminate Water?

Surface and groundwater sources can be contaminated with nitrites when rainfall causes a runoff. The falling water comes into contact with sewage or residual fertilizer sources which is directed into streams, rivers, and other surface water. Groundwater can also be contaminated via contact with certain mineral deposits.

What are the Environmental Consequences?

When high concentrations of nitrites and certain other nutrients are added to the environment it can lead to a number of problems. The formation of algal blooms (eutrophication) in ponds and lakes is a more noticeable consequence. If you look closely, you may notice the effects of the depletion of oxygen (hypoxia) which kills flora and fauna alike. Another common problem is the formation of cyanobacteria blocks which form toxic compounds that are harmful to humans, animals, and aquatic life.

What is the Connection with Nitrosomonas Bacteria?

If you’ve looked into the problem of nitrites as water contaminants, you may have heard of Nitrosomonas bacteria. Nitrites can enter the water supply when manure or fertilizer runoff leaches into the runoff. Other possible causes may include septic tank effluent, raw sewage, decaying animal and plant matter, and more. Badly constructed, shallow and damaged wells are very prone to nitrite contamination. Nitrosomonas bacteria can be found in water distribution pipes and under certain conditions, this may produce nitrites. This is most common in galvanized steel pipes where the water has a low concentration of oxygen or if chloramines (chlorine mixed with ammonia) has been used as a disinfection agent.  The production of nitrites in the environment is known as nitrification because the ammonium has been converted to nitrites and then nitrates. There are other types of nitrifying bacteria, two of the most common are nitrospira and nitrosococcus.

What are the Negative Health Consequences?

When nitrites are present in a given source of water, it’s a sign that there may be other water quality problems. In a private well, the presence of nitrates may indicate the presence of coliform bacteria and/or the well structure may be compromised. Nitrites may indicate that there are unhealthy levels of nitrates in the drinking water. The concentration of nitrite in drinking water should be below 0.1 mg/L (or ppm) to be healthy.

If the drinking water contains nitrites, there are significant health risks for vulnerable groups, including elderly people, pregnant women, infants, and mothers that are nursing them. A well recognised consequence of exposure to nitrates in babies is “blue baby syndrome” or methemoglobinemia. The baby has blue skin because its red blood cells cannot carry oxygen around the body efficiently. At risk groups should avoid the consumption of drinking water that contains high concentrations of nitrites or nitrates.

How Can I Remove Nitrites from My Drinking Water?

There are a number of ways to remove nitrites and nitrates from your drinking water, including boiling, distillation, ion-exchange, carbon adsorption, and reverse osmosis filtration. It’s important to understand that a standard water softener system will not remove these contaminants at all.

Distillation is an ancient method to purify water via an evaporation and cooling process. The water is brought to a rolling boil, the steam accumulates on a surface and as the vapor cools this water is collected. During this process, all the nitrites and any other dissolved solids that may be present are left behind. The collected water is virtually pure and safe to use but there are significant disadvantages. Even a modern distillation unit cannot produce significant volumes of clean water during a typical day. Plus, the constant water boiling consumes a lot of energy which leads to higher utility bills.

An ion-exchange filter removes a number of contaminants including nitrites with an adsorbing process. The ions are exchanged in filter cartridges that are usually installed as a point-of-use system at a single tap in the home. The most common location is the kitchen sink or with larger whole-house systems all the incoming water is cleaned. These ion-exchange filtration systems remove many contaminants, including nitrites, nitrations, sulfates, and more. The main drawback with these types of systems is the resin media which are primarily designed to adsorb sulfate ions. They can be less effective at removing nitrite ions if the sulfate concentrations are very high. This filter must be regenerated or replaced regularly or it will become saturated quickly. If the sulfate ions are allowed to replace the nitrate ions that have already been absorbed in the filter the concentrations of nitrites will increase!

Reverse osmosis or RO is one of the best filtration systems because it’s mechanical and it removes a large variety of contaminants. The system relies on a semi-permeable filter membrane which has tiny pores that allow water molecules to pass through. The larger ions are left behind on the membrane surface and they are periodically flushed away. This process takes time and the cleaned water is held in a storage tank for future use. The RO system is typically installed as a point-of-use unit at the kitchen sink. The drinking water is cleaned to an exceptional standard and a few gallons can be created every day.

If you want to learn more about removing nitrite and other contaminants from your drinking water, contact your local water treatment specialist today.