Nitrate
Summary: Nitrate (NO3−) forms from fertilizers, septic systems, and natural soil processes. It moves quickly through soil into wells, especially after rain or irrigation. Because nitrate has no taste or odor, testing is the only way to know your level.
Why homeowners should care
Elevated nitrate is a concern for infants and pregnant people and can indicate broader contamination from septic or agricultural sources. Levels can change seasonally—one safe test years ago doesn’t guarantee safety today.
Where nitrate comes from
- Fertilizers & agriculture: Lawn, garden, and farm applications that leach into groundwater.
- Septic systems: Leaks, aging systems, or drain fields too close to the well.
- Natural/soil processes: Nitrification of organic matter, especially in shallow wells or sandy soils.
When to test
- At least annually for private wells.
- After fertilizer season, heavy rains, droughts, or changes in nearby land use.
- Any time taste/odor changes or a newborn joins the household.
How we test
HealthWaterLab uses a laboratory colorimetric cadmium-reduction method with low-level detection and QA controls. For borderline results, we recommend a confirmation sample to verify trends.
How to collect a good sample
- Use the kitchen cold-water tap or your primary drinking tap.
- Run water several minutes to flush; remove aerators if instructed.
- Fill the bottle to the marked line; avoid touching the inside of cap/bottle.
- Keep cold and deliver to the lab promptly.
How to read your result
- Low / typical background: Keep annual testing, especially after seasonal changes.
- Near the limit: Confirm with a second sample; consider using treated water for infants as a precaution.
- Elevated: Treat drinking/cooking water and investigate sources (fertilizer use, septic setback/maintenance).
If nitrate is elevated: practical next steps
- Point-of-use reverse osmosis (RO): Under-sink RO reliably reduces nitrate for drinking/cooking.
- Whole-home options: Anion exchange systems can reduce nitrate to all taps when house-wide treatment is desired.
- Control the source: Maintain/repair septic systems; manage fertilizer timing/rates; improve well siting and surface drainage.
- Verify performance: Retest treated water to confirm removal and recheck seasonally.
FAQ
Can I taste or smell nitrate?
No—nitrate has no taste or odor. Only a lab test can tell you the level.
Does boiling remove nitrate?
No. Boiling concentrates nitrate. Use RO at the kitchen tap or a certified system designed for nitrate reduction.
What is reverse osmosis (RO)?
Reverse osmosis is an under-sink drinking water system that pushes water through a very fine semi-permeable membrane. The membrane rejects many dissolved contaminants (like arsenic, nitrate/nitrite, lead, copper, and salts), producing low-TDS water for cooking and drinking.
How it works: Pre-filters remove sediment and chlorine → the RO membrane removes dissolved ions → an optional carbon “polishing” filter improves taste → treated water is stored in a small tank and dispensed at a dedicated faucet.
Good to know: RO is point-of-use (kitchen sink), not whole-home; filters/membrane need periodic replacement; some water is sent to drain during operation. If you prefer a little mineral taste, a small remineralization cartridge can be added.
Is a water softener enough?
No. Softeners target hardness (calcium/magnesium). Use RO or anion exchange designed for nitrate.
Should I also test for nitrite?
Yes—nitrite (NO2−) can appear during microbial activity. Many labs report both together.
Which faucet should I sample?
The main kitchen cold-water tap. If you install treatment, sample the treated faucet to verify removal.
Is RO water okay for mixing baby formula?
Yes—RO is recommended where nitrate is elevated or uncertain. Verify performance with a quick follow-up test.
Why did my level change this season?
Rain, irrigation, fertilizer timing, and groundwater level shifts can change nitrate quickly—seasonal testing helps track trends.
Do pitcher/fridge filters remove nitrate?
Standard carbon filters do not. Look for RO or systems specifically certified for nitrate reduction.
My neighbor’s well is fine—am I safe?
Not necessarily. Nitrate varies well-to-well based on depth, geology, and nearby sources. Test your own tap.
Ready to test? Order a nitrate (and nitrite) kit with step-by-step sampling instructions at HealthWaterLab.com.