Friday, September 27, 2013

How to Remove Nitrate from Well Water for My Home?

I am moving to a home with a well that tested high in nitrates (81 mg/L).  What do you recommend?  I can send the complete well report if you would like.  Thanks!


Hello John,

Thanks for emailing.  If you could please send us the water test report you have to, we can take a look at it and recommend a system.

You could use a whole house nitrate filtration system, or an under-sink point of use system for drinking water only.

Sometimes the water is very hard (over say 100 ppm of calcium carbonate) then a water softener or conditioner is needed ahead of the nitrate filter.    Both the sulfate and nitrate must be taken into consideration when sizing an anion nitrate filtration system, so it is important to have a sulfate test along with general mineral and physical water analysis.

Here is more information on these systems:
Nitrate filter and Brine tank

This size is typical model for many homes with 1 - 2 bathrooms

The sizing is based on the well water flow rate and the number of persons and bathrooms in the home.


Frequently Asked Questions About Nitrate Systems

Here are some common questions we get:

Q. How do these systems remove nitrate?

A. These systems use a type of filtering resin called “anion exchange resin.” Anions (in this case nitrate and sulfate) are selectively removed in the process. As the nitrate is removed, non-toxic chloride ions are substituted in a process known as “ion-exchange”.

Q. Why do these systems use salt?

A. After the filtering resin removes a given amount of nitrate, the resin becomes “exhausted” and cannot remove any more nitrate or sulfates. At this point the media must be cleaned in a process known as “regeneration.” The salt is used as the “regenerant” which restores the resin and allows it to remove nitrate again.

Q. Since this uses salt, does this soften the water?

A. No. Salt does not soften water. Salt is also used in water softeners, which are “cation exchangers,” where the softening resin removes calcium hardness and substitute’s sodium ions. In nitrate anion exchange systems, the chloride ion is used when the system automatically cleans itself with brine or salt water. No softening takes place.

Q. How will I know if the system is working?

A. It is very important to regularly test the filtered water for nitrate. Nitrate is especially toxic for infants and fetuses; we recommend further treatment by distillation or reverse osmosis, if this water is to be used for infant formula or by pregnant mothers.

Q. Can I taste or smell nitrate?

A. No. Nitrate is colorless, odorless and does not impart a taste to water. For this reason it is very important to frequently test the water before use, especially if the water is to be used for drinking by pregnant mothers or infants.

Q. Do these nitrate systems purify the water for drinking?

A. No, these systems only reduce nitrate and sulfate. No purification takes place other than the reduction of these compounds. If the water is high in nitrate as a result of agricultural contamination or run-off, there is at least the possibility of the presence of other toxic compounds such as pesticide or herbicide residuals.

Q. Is it harmful to shower in high-nitrate water?

A. It is not harmful to shower in water high in nitrate. We typically see nitrate in area wells in the form of calcium nitrate. Unlike organic compounds such as hexane or benzene, calcium nitrate is not absorbed through the skin.

Q. Why not just treat the water at point-of-use for drinking?

Nitrate two stage
A. This is sometimes the best approach, since nitrate is not considered toxic to shower in. A Reverse Osmosis System can often remove 90% of the nitrate, or point of use anion nitrate filter cartridge systems are used.

Most of the nitrate systems we have installed are used to comply with Health Department regulations requiring that all the water be treated throughout the home or community.