NitrAtes in my tap water

[WaterBaby]

I just happened to check my tap water (which I "occasionally" do) for ammonia. This time I had some time to kill and checked for Nitrates.....

WHY?...

do I have nitrates in my tap water? They are about 10ppm.

How do they occur in tap water?

And how do I get rid of them?

[DEmigh]

One of the sources of nitrates in tapwater is runoff from fertilized fields. Joe Farmer wants his crops to grow, so he supplements with ammonium nitrate (or some such). Along comes a rain and pretty soon you're drinking water has been fertilized.

Edited for grammar.

[WaterBaby]

But we have "City Water", not well water. Is that still possible?

[DEmigh]

Perhaps even more likely. While some aquifers are polluted with nitrates, (and it occurs naturally in some others), "City water" is more likely to come from reservoirs that are fed by runoff. Municipal water departments typically don't concern themselves with nitrates.

[mogurnda]

David summed it up pretty well.

I am smack in the middle of the city, and we have about 10 ppm nitrate. I assume the NO3 is there because of the treated wastewater and farm runoff that has been added along to the Potomac the way. We get it at the end of the line.

Municipal systems care about NO3, but I think 10 ppm is the limit around here.

One solution at your end is to get a reverse osmosis (RO) system, or buy RO water and dilute your tapwater with it. Plive plants will also reduce NO3, but you have to spend some time getting to know them before you can use them for export.

[JSchmidt]

10 ppm won't really harm anything. The EPA limit for chronic levels of nitrates is 44 ppm. We routinely have 20 ppm here in the heartland.

Jim

[RTR]

Just a minor clarification before folks get confused. The regs are written on nitrate-nitrogen, with the maximum allowable level being 10ppm nitrate-nitrogen. Most hobby test kits measure total nitrate. The conversion from nitrate-nitrogen to nitrate is: Nitrate nitrogen x 4.4 = nitrate.

So everybody is right, the magic number is 10, but you need the units of measurement to be able to read it properly. Or the magic number is 44, depending on the units.

Everybody is also correct on agricultural (and suburban lawn) runoff causing the nitrate titer. That is a big deal around here with the Bay. Anybody want to talk about the Eastern Shore's contribution from chicken farms?

No, that would be Chat. :shake:

[Aquarius0015]

Yeah, I live on the Eastern Shore when I'm not at school. We have a chicken farm next door and my step-father works for Perdue Farms. Good old homogenous Delmarva...