Nitrogen is a natural compound that is present in most groundwater throughout the United States. However, many sources of groundwater can have higher than recommended nitrate concentrations, so how to test for nitrates in water to know if it’s safe?
Though nitrate is an essential nutrient for survival, the nitrogen and oxygen compound can be harmful to human health in high concentrations.
In this guide, I’ll cover the best methods to collect a drinking water sample and perform nitrate testing on your well water to determine your exact nitrate levels, and how to treat your water if you test positive for high amounts of nitrate.
What Exactly Are Nitrate and Nitrite?
Though they both contain nitrogen, nitrate, and nitrite are two different compounds. Nitrate is a compound composed of one nitrogen atom and three oxygen atoms. In a water sample, the nitrogen component of the total nitrate is referred to as nitrate-nitrogen.
Nitrite is composed of one nitrogen atom and two oxygen atoms. Nitrate contamination is more common between the two, but both compounds can be present in water.
Between the two, nitrite is a less stable compound of nitrogen which can be highly dangerous in high concentrations. Nitrites can bond with oxygen atoms in the bloodstream, causing a dangerous condition known as methemoglobinemia which is particularly dangerous for infants.
How Nitrate Gets Into Well Water
Nitrates are naturally produced by plant decay and, as a result, can be found in groundwater virtually everywhere. However, high levels of nitrate contamination in drinking water that pose health risks generally result from human-made sources.
The primary sources for higher-than-usual concentrations of nitrates and nitrites in drinking water include:
- Fertilizer runoff from agriculture, golf courses, and yards
- Discharge from sewer systems
- Leaking septic systems
- Animal waste in surface water
- Improper waste disposal and industrial activity
- Natural deposit errosion
Nitrate contamination can naturally seep into well water due to these factors, but it can be exacerbated by a damaged well casing. Flooding may also carry nitrate contamination from septic systems and other nitrate carriers. This can particularly affect shallow wells, which acquire surface water from higher in the water table.
Should I Test My Water for Nitrate & Nitrite?
For those with private wells, it is important to regularly test water quality, and this includes a nitrate test and nitrite test of water samples to have their concentrations measured. Although nitrate occurs naturally in surface water, a concentration higher than 3 mg/L typically indicates contamination from human activity. This is particularly true in agricultural areas where fertilizer use and animal waste are common.
The Environmental Protection Agency (EPA) has a maximum contaminant level for nitrate nitrogen in drinking water of 10 mg/L. Nitrite, on the other hand, has an EPA maximum contaminant level of 1 mg/L. Anything above these levels is considered harmful to human health.
As a quick check, you can look at the EPA Groundwater Data Table to see what percent of your state has concentrations of nitrate in groundwater above 5 mg/L. If you are on a public water system, you can check the Water Quality Report to see if any nitrate was detected. It is highly recommended to test your water if you live in one of these high-risk areas
Elevated consumption of nitrate and nitrite in drinking water can be linked to negative health effects, such as:
- Thyroid disease
- Shortness of breath
- Excess heart rate
- Blue baby disease
Nitrate consumption is particularly sensitive for infants under 6 months who can become seriously ill or even die if untreated. Therefore, you should test your water more frequently if you are pregnant or have a newborn child.
For private well owners and even users of public water supplies, it is recommended to have an accredited laboratory test for nitrate levels at least once per year and then consider possible treatment options.
How To Test for Nitrate in Private Wells
Nitrates and nitrites have no taste, color, or odor, so nitrate testing is the only way to know if they are present and in what concentration. There are at-home nitrate testing kits that can inform you of nitrate levels, but the accuracy of these tests can vary widely. At-home kits are generally test strips or cadmium reduction kits.
The best way to handle nitrate testing is to have an accredited laboratory perform an accurate test of your drinking water to detect the exact nitrate/nitrite levels in your well water. Certified laboratory testing can provide comprehensive testing for different contaminants, including nitrates and nitrites.
Certified Laboratory Nitrate Testing
A certified laboratory will provide you with professional testing for nitrates levels in your drinking water. With laboratory testing, you will receive a nitrate testing kit that you return to the laboratory with a water sample from your home.
I recommend using the Freshnss Labs kit to test your well water for nitrate and nitrite. This kit will not only provide the exact detection levels, but it also tests for dozens of other common well water contaminants.
How To Collect Samples
In order to test your water, the laboratory will need a sample of your well water. The kit will arrive with instructions and water sample collection bottles. This means you need to take a sample from a faucet that outputs before any water softeners, disinfection units, or filters. Here are precautionary steps to follow to ensure accurate testing results:
- Disinfect your faucet surface area with diluted bleach or rubbing alcohol
- Wait at least 5 minutes to let the disinfectant dissipate
- Turn on your tap and let it run for 30 before collecting your sample
- Wear clean rubber gloves if you have them available to avoid cross-contamination
- Turn on cold water supply and slowly collect your sample so it does not overflow
- Then simply package the samples as instructed and send them to the lab for analysis
Follow these steps carefully for your testing kit. It is possible for you to contaminate the sample and any contamination of your water sample can lead to a false positive.
What To Do If Water Tests Positive for High Levels of Nitrate?
In the event that the sample of your well water tests positive for high nitrate concentration, you will need to start drinking bottled water until you can arrange a permanent solution. Here are a few different ways that you can treat well water with nitrate contamination to reduce your exposure.
Reverse osmosis is one of the most effective water treatment solutions for removing excess nitrates for private well owners. Reverse osmosis can remove up to 92% of nitrates specifically and up to 98% of all waterborne contaminants.
The reverse osmosis process works by forcing pressurized water through a fine semi-permeable membrane with microscopic pores. This essentially acts like a sieve letting the hydrogen and oxygen that makes up water through while blocking other contaminants, including nitrates.
The clean drinking water is then passed into a storage tank where it can be used. The contaminants cannot pass through the membrane and are instead flushed down the drain by a brine-cleaning solution. Reverse osmosis is one of the most powerful water treatment solutions and is ideal for nitrate contamination.
Ion exchange systems are generally similar to those used to soften water, but they are useful for removing nitrate from water as well. These systems are point-of-entry systems and will treat all of the water in your water system.
The nitrate is removed by using a strong base anion exchange resin. This resin is regenerated with everyday salt. The anion exchange site makes use of the chloride ion in the salt. Then, the sodium ion goes through the resin bed without affecting the process.
There are two primary types of resins you could use for the ion exchange process, standard resins, and selective resins. Standard resins will supply a higher operating capacity unless your water has a large amount of sulfates. But nitrate selective resins could be a better choice if you will not be monitoring your application closely, and an overrun is possible. These selective resins will effectively remove nitrates while preventing nitrate dumping.
Nitrate dumping happens when Type 1 or Type 2 resins, which are non-selective, are run beyond the end of the typical nitrate removal service cycle. This can cause sulfates to keep loading onto the resin bed, which forces the nitrates off and results in dumping. If dumping happens, the nitrate concentration of the treated water can come close to the total concentration of the combined nitrates and sulfates contained in the untreated water.
Distillation will boil, evaporate, and condense your water. This will cause impurities that won’t evaporate, such as nitrate, to remain in the boiling chamber. The water will leave the chamber and condense into a container without the contaminants.
This method is very effective at removing almost all contaminants. Distillers are also economical, as they don’t have the added expense of requiring filter changes. Also, the purchase price for a countertop distiller is quite affordable at a low-end cost of approximately $100.
However, there are some disadvantages to distillers as well. Distilled water does not have much taste. Also, the distillation process removes healthy minerals in addition to impurities. Moreover, distillation is a slow process. It takes around four to six hours to make one gallon of distilled water. So, for larger families that want all of their drinking water filtered, this method would likely not be a good choice.
Frequently Asked Questions
How do you test for nitrates in drinking water?
Nitrate testing at home is typically done with testing strips or with the cadmium reduction method. However, these types of tests are less accurate and do not provide the specific concentration level. The best testing method for nitrates is to use a certified laboratory that will provide the specific nitrate and nitrite levels in your well water.
What are the symptoms of nitrate poisoning in humans?
Elevated nitrate concentrations can lead to shortness of breath, dizziness, and elevated heart rate. However, infants are at elevated risk and can suffer severe illness, blue baby syndrome, and even death.
Should I test for nitrates in water?
Significant nitrate concentration can come from animal wastes, fertilizers, sewage, and natural runoff. It is strongly suggested to test your drinking water supply for nitrate at least once per year. Negative symptoms included thyroid disease, dizziness, and blue baby syndrome.
Does boiling water remove nitrates?
No, Boiling water does not remove nitrate in water and can actually increase the concentration because some of the H2O will evaporate while the nitrate does not.