City tap water and nitrate

[Kichi]

I tested storage of water in a 5 gallon HDPE bucket with covered lid.

Ammonia, Nitrate, and Nitrate tests done with API Master Test Kit.

1) RO water initially tested zero in all three categories. After one week, there were no changes.

2) Tap water (with simple dechlor, not water conditioner) initially tested zero in all three categories. After one week, nitrate tested orange and then two weeks became red (40ppm+). Ammonia and nitrite undetectable.

I became aware of this issue when trying to store large amounts of premixed RO and tap water for use at a later time. So I tested the water separately and found tap water was the culprit.

Could someone please explain how and where this is nitrate coming from?

 

[Bertie07]

I tested storage of water in a 5 gallon HDPE bucket with covered lid.

Ammonia, Nitrate, and Nitrate tests done with API Master Test Kit.

1) RO water initially tested zero in all three categories. After one week, there were no changes.

2) Tap water (with simple dechlor, not water conditioner) initially tested zero in all three categories. After one week, nitrate tested orange and then two weeks became red (40ppm+). Ammonia and nitrite undetectable.

I became aware of this issue when trying to store large amounts of premixed RO and tap water for use at a later time. So I tested the water separately and found tap water was the culprit.

Could someone please explain how and where this is nitrate coming from?

I’ve had the same problem with my tap water except it shows about 20ppm straight out the tap, they must not remove nitrates when treating the water.

 

[Kichi]

I’ve had the same problem with my tap water except it shows about 20ppm straight out the tap, they must not remove nitrates when treating the water.

You seem to have nitrates clearly in your tap water then. My initial tap water started with no detectable amounts of ammonia, nitrite, or nitrates to begin so the mystery is how it gets the nitrates over time. My tap water is chlorinated (not chloramines).

 

[twentyleagues]

Did you test it without dechlor in it? If so what was result?

 

[Kichi]

Did you test it without dechlor in it? If so what was result?

I want to say I did but I want to make sure and get back to this in another week. Initial results are undetectable by API test kit in all three categories.

According to https://www.ewg.org, my city has a reported average rate of 3.39 ppm Nitrates from 2010-2015. Health guidelines are 5 ppm and under. Legal limit is 10 ppm.

Anyways... Need some chemistry here... Brainstorming how perfectly clean water becomes fertilizer in a week...

Chlorine in water... we have hypochlorous acid (HOCl), and hydrochloric acid (HCl)
Weco Dechlor (sodium thiosulfate ).... Na2S2O3
Nitrates.... NO3-

 

[tiger15]

First, you have to check that your test results are good. API nitrate is notorious in that you need to shake the second reagent vigorously to attain uniform concentration and thereby correct result. Second, it's common to have nitrate in tap water in area polluted by farm fertilizers. No big deal to fish if your readings for ammonia and nitrite are non detectable. Nitrate is harmless to fish up to 100 ppm.

According to https://www.ewg.org, my city has a reported average rate of 3.39 ppm Nitrates from 2010-2015. Health guidelines are 5 ppm and under. Legal limit is 10 ppm.

Be aware that the legal limit of 10 ppm is nitrate nitrogen, which is convertable to higher number if expressed in NO3.

 

[duanes]

If your tap water provider uses Chloramine (AKA Total Chlorine) as a disinfectant, (1 part ammonia/5 parts chlorine) this may be where your buildup of nitrate is coming from, in a storage container, biofilm on its walls may be converting that 1 part ammonia into nitrate as it sits.
My water provider used Chloramine, and throughout the cities distribution system, bio-film of ammonia consuming bacteria converted that % of ammonia to nitrate in the miles and miles of pipes.

 

[squint]

Ammonia in your air entering the water and undergoing nitrification?

 

[Mr Pleco]

If your tap water provider uses Chloramine (AKA Total Chlorine) as a disinfectant, (1 part ammonia/5 parts chlorine) this may be where your buildup of nitrate is coming from, in a storage container, biofilm on its walls may be converting that 1 part ammonia into nitrate as it sits.
My water provider used Chloramine, and throughout the cities distribution system, bio-film of ammonia consuming bacteria converted that % of ammonia to nitrate in the miles and miles of pipes.

this is the issue Im fighting , plus nitrates being up to 10PPM in tap water. now with the floods the chemical disenfection levels are through the roof .. No boil order because is my understanding you cant boil out AMM ? Yet tap water is not advised for small pets, infants or the elderly , also may cause respiratory distress in people with asthma from showers... WTF... had a two week ban on tap by city , one day tap water was milky white.. to OP I believe Duanes hit the nail on the head if you have chloramine in your water

 

[Rocksor]

Chloramine treated water will show ammonia in the API Ammonia test since it will test total ammonia in the water, whether it is free ammonia or bound ammonia. The OP's water tested for 0ppm ammonia on the first day.

But, if the container is never disinfected prior to a refill, then I can see the container being contaminated with bacteria.