Possible Well Water Contamination.

[Briandajew]

Hi,

we currently use water from a shallow bore well - about 8-10 metres deep, this is pumped into a storage tank/filter (sand gravel) that contains about XXXX CORRECTION(8000) litres of water, this is then fed into a secondary tank again with about another metre or so of sand gravel as a filter. (The tanks are about 2.8 metres deep and 1.8 metres in diameter)

This method has worked for over 5 years and water has been pretty much OK providing the iron contnet is removed from the sand every few weeks.

In the last two days the water has had a foul smell, it actually smells like an animal has died inside the tanks. I am about to drain everything tomorrow and try to find out the cause. Does anyone have any idea as to how to sterilize the tanks and clean the pipework supposing it is a dead animal?

I am intending to use household bleach or caustic soda and flush everything out, anyone have any idea as to the quantity of bleach/caustic soda for 4000 litres that will kill bacteria without causing problems with eyes/skin etc. The water is used for washing, dishes etc, and all drinking water goes through another set of charcoal/UV/Osmosos filters and has none of the odour.

Also, what would be the effects of ingesting any of this water, cleaning teeth washing plates etc?

Whatever has died in there cannot be very big, lizard, bird rat or snake as the tanks are 2 metres above ground and the second tank is screened with a fine mesh so the only possibility would be the first stage filtration tank and yes we have had things like frogs get in there and those Toktaw lizards.

Thanks for any advice.

Edited November 14, 2012 by Briandajew

[Briandajew]

Update - my calculations are not what they should be! The two tanks are 1.2 metres diameter by 2.8 metres in height, the actual capacity is about 6000 litres for the two - which from what I can gether from the internet requires 4mg/ per litre of chlorine.

However, I have been out tonight and checked the tanks and the water smells really clean, no hint of dead flesh. so there must be something in the pipework......how do you go about flushing death out of 1/2"plastic pipes?

[stoneyboy]

I wish I could I help you but life is so sophisticated here in Lom Sak Phetchabun that my water comes directly to the house via the mains,most of the time that is.

Good luck I hope you flush out the problem soon.

[h90]

Don't know but when I was young SO2 was always popular for everything, by burning sulfur.

(maybe that is outdated now??)

[BigJohnnyBKK]

Sure hope you're just using this water for flushing the dunny and washing clothes, not for any human consumption is all I can say.

Note as this isn't Thailand-specific you'll probably get better answers on an "off the grid living" type of forum, or maybe just by some clever google-<deleted> to standing reference resources.

[Briandajew]

Not a bump - just an update - thanks for the advice regarding the Caustic Soda - I didn't dare use it after I had be burned by it once before and nearly lost my eyes!

I found out the source of the smell, we had a dead rat the size of a large cat floating in the CLEAN side of the water tanks!!!! My fault I suppose, I let some tree branches grow too near the tank and this bugger must have ran up them, strange how it managed to get through the netting I have on the tank though, anyway, it is good to still be alive after brushing my teeth for the past 4 days or so and drinking tea and coffee along with various meals, all cooked with a diluted dead rat soup - disgusting eh!

I did a recalculation on the water volume and I think between the two tanks there is about 4000 litres, so we drained everything after scooping out the dead rat (I tried to burn it on a little funeral pyre as it was stinking - but it seems one of the dogs has taken it for his supper - nice barbeque..mmmmmmmmmmmmmmmmm! boy it was stinking) cleaned it all out and stuck 2 litres of 6% chlorine bleach into it - at the moment just trying to let the system soak to kill any bacteria. Slightly worried about Weils disease, as it can take up to 3 weeks to show, but at least we know what it was! - Ugh!

[BigJohnnyBKK]

Yep pretty gross. Suggest a heavy-guage metallic mesh rather than anything rodents can chew through.

Or even springing for those self-contained steel ones just for the drinking water, don't have to size too large in this climate if you're topping them up from a well designed roof catchment system (dust/leaf traps etc).

Lots of good free tech docs available on this, particularly from Australia and the western US.

I personally wouldn't use well water in an agricultural area for human consumption.

[sbk]

Moving to DIY forum, lots of householders there