Replied by Michael (New Zealand) on 06/29/2016

Your question interested me, as I used to live in a rural location of northern New Zealand and we had to be extremely careful what we put in our septic tanks or they might die on us!!

I have consulted an expert from an organization I rely on for technical matters and the passage below is an extract from what they wrote to me. In any event, you should have them emptied every 2 - 4 years depending on numbers using it. I hope this is useful for you:-

"I am not sure about the specifics of your septic tank system but our technical writer says that:

€According to the "Environmental Engineers Handbook", diatomaceous earth is recommended as a pre-treatment filter cake through which waste passes before it hits the tank. They claim €œit removes bacteria and some viruses€. The question is whether it removes just the bad bacteria in the waste or whether it will also remove the good bacteria in a septic tank that breaks down waste.

Apparently, diatomaceous earth has a negative charge. So if the bacteria in the tank has a positive charge then it could indeed remove them from circulation in the septic tank, meaning the waste won't break down as well. But if it had a neutral or negative charge then it would be fine.

Septic tanks will be full of anaerobic bacteria (which don't require air) that break down the waste in the tank. According to this paper, biodegradative anaerobic bacteria usually have a negatively charged cell wall.

So I would say the presence of diatomaceous earth wouldn't negatively affect the good bacteria in the tank. However, it'd be good to limit its inflow so that the inlet and outlet don't get blocked. But as long as the tank is being pumped every couple of years it should be fine.

I hope this helps.

Replied by Mama To Many (Tennessee) on 06/27/2016

Now that is a good question! As someone with a septic tank also, I can certainly appreciate the concern! (I just never thought to be concerned until you brought this up.)

From what I read, DE has a positive electric charge and that "bad" bacteria would be attracted to it and removed from the body (septic tank, too, maybe?), but that good bacteria would not be harmed by it. Also, the typical mechanism for DE seems to be that its sharp edges are cutting small insects and parasites. I am not aware of them having this effect on the cell wall of bacteria, but I admit I haven't studied it either.

Perhaps our Chemical Engineer, Robert Henry would have some wisdom for us here on the subject?

Meanwhile, if you are concerned, for your eczema, you could try one of Earth Clinic's many other great remedies, or make a paste with DE in it to use topically for eczema.

~Mama to Many~

Replied by Robert Henry (Ten Mile, Tn.) on 06/28/2016

Your logic of how DE works is what the Big Boys around the pool table say. Sorry, but my contribution would be a guess. We do take DE and use it on our garden plants to kill insects.

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