Private Well - Disinfection

craic90

Hi,

First time well cleaner here - and just wanted to ask a few questions of someone who might have done this procedure already - or might know more about it. We got a water report back with cloriforms (3 parts) and e-coli (1 part) and have been advised to disinfect the well.

We have bought a 25L drum of Coop Source Chloros. (Soduim Hypochlorite Solution 87g/KG (10-11%) to pour into the well.

So I have a couple of questions:

1. I've seen a couple of internet articles that suggest they have used something like 5-6% solution. Did we buy the wrong stuff here?
2. What is the recommended procedure for pouring this stuff into the well - specifically in terms of how much etc we should be putting in.

Thanks for any advice offered!

Curly Judge

craic90 wrote: »

Hi,

First time well cleaner here - and just wanted to ask a few questions of someone who might have done this procedure already - or might know more about it. We got a water report back with cloriforms (3 parts) and e-coli (1 part) and have been advised to disinfect the well.

We have bought a 25L drum of Coop Source Chloros. (Soduim Hypochlorite Solution 87g/KG (10-11%) to pour into the well.

So I have a couple of questions:

1. I've seen a couple of internet articles that suggest they have used something like 5-6% solution. Did we buy the wrong stuff here?
2. What is the recommended procedure for pouring this stuff into the well - specifically in terms of how much etc we should be putting in.

Thanks for any advice offered!

A lot depends on the source and type of contamination.
Is it is a continuing source or a once off accident?
If a once off accident then repeated pumping would be my solution.
If continuing pollution is the problem there are several disinfecting systems on the market ranging from filtering, ultra violet light to reverse osmosis and the use of chlorine combined with a settlement tank system.
Bear in mind that all the second mentioned systems involve sterilising the supply to the house rather than the well.
Trying to sterilise a continually polluted well itself is , in my opinion a waste of time and money

craic90

Thank you for the answer.

It's impossible to know as we have been living in this house for 4 months, and this is the very first instance of any water report. It is a new build, and we are the first residents.

In any case - we will only know the answer to your question after we disinfect and repeat with multiple tests to identify if this is a recurring problem or not.

Curly Judge

craic90 wrote: »

Thank you for the answer.

It's impossible to know as we have been living in this house for 4 months, and this is the very first instance of any water report. It is a new build, and we are the first residents.

In any case - we will only know the answer to your question after we disinfect and repeat with multiple tests to identify if this is a recurring problem or not.

(Is the well itself old or new and is it a dug well (shallow well) or a bored well (deep well)?

Calahonda52

Op: I don't get the sense here that you appreciate how serious this issue is.

Both of these bugs, in the correct amount, can kill, not just you but visitors and if it came out that you knew the water was dodgy I would not like to see the litigation numbers because every insurer will walk.

Testing after someone is in the morgue is a tad late.

Horsing down a random 25 or 50 litres of some random disinfectant at a random concentration is not the right approach.

Then what impact will this random stuff have on you.

I don't know the right answer but is not a job for the www

Just saw these guys drive down the road...http://www.thewaterlab.ie

craic90

Hi Calahonda.

Very much understand the issue - which is why we are on 100% on bottled water until we retest further. Having said that - we already checked with several professionals in the 'water treatment' domain (actual people, not www pages) - who advised that whilst e-coli is unquestionably dangerous - at current levels we have - we are not in imminent danger.

Every similar company to yours (thewaterlab.ie) - have advised us - that well disinfection is 100% something that can - if not - should be done by yourself.

dathi

craic90 wrote: »

- that well disinfection is 100% something that can - if not - should be done by yourself.

this is correct advise your co-op bleach is fine, to carry out this pour it down the well head and then run the kitchen tap until you can smell bleach, then leave over night. then run the taps until all odour of bleach is gone . have the water re tested after doing this and again in 3 months to make sure that there is not an ongoing problem with contamination. also make sure your well head is covered and protected . main cause of ecoli is contamination from septic tanks or slurry.

ferryman35

I have a similar situation to you!

there is an guide published online by the EPA or HSE that gives detailed instructions very similar to those posted by daithi - if i can find it I'll post a link later.

Your co-op chloros s fine - but because its probably a 10% solution you use less of it - so probably 1-2 litres will be loads.

The recommendation is to mix a solution of probably 1-2 litres in a 25 litre drum. Pour half in and run the furthest away tap (and even every tap) until you smell the chlorine at the tap point. Then pour the balance in the well and leave overnight.

Next day run the taps until you can't smell the chlorine and job done. Our local lab will run the microbiological tests on their own for something like €40ish.

Make sure the well head is closed and elevated above ground level so that contaminated surface water can't seep in.

For peace of mind it's not too expensive to treat the water to make it safe. This can be done by filtration followed by UV sterilisation.

The Bacteria can hide behind impurities in the water so you filter it (can go down to 5 micron filters), and the UV lamp zaps the bugs! You need to change the UV lamp annually.

If you choose fancier treatment just check that it is compatible with whatever plumbing kit you have in the house because I believe that reverse osmosis treated water is detrimental to stainless steel.