Well water testing

Client contacted a well company to ask about chlorinating a well that tested positive for presence of bacteria.

The well company said that the sample would be “offset” and show bacteria if the sample was taken anywhere near a p-trap in the house due to vapors.

They say it should be taken at the well head only.
I followed the lab instructions… nothing there about that.

Anyone ever heard of this p-trap vapor thing?

I always been told to take the sample as close to the source as possible, but the vapors from the trap I have never heard of.

I always thought the P trap was designed to keep the vapors out of the house.:smiley:

Thats nonsense about the P-trap. Its more likely you can contaminate the bottle opening by accidently touching it with fingers or other contaminated surfaces.

You should also let the water run for several minutes and do not draw a sample from downstream of any filtering, softner, UV system. Try and take it as close to the source as possible. Thats pretty hard to do directly from the well.

I’ve taken many samples following the state certified lab’s protocol and never have heard this before. It sounds suspect. :roll:

Just found out, state law says only take samples from the interior house faucets.

This ensures the whole system is checked including the filter.

People don’t go out to the well for a drink, they get it from the faucets.

Sounds like the well company does not want to do maint. type work.

As a purchaser I would want to know if the well has a problem, if it does I would want the opportunity to have the vendor correct it or take further inquiries through testing, or well contractor, or health department to ascertain the source. In most all circumstances up here rural properties with wells have their well water tested for bacteria as requirement of the purchase/sale fwiw.


Sounds more to me more like the well company is trying to discredit anyone but a well company from doing quality inspections/tests.

We have one contractor up here who is notorious for working on wells without having a licence. I have seen three such wells worked on by this dufus, and I have seen another contractor who has screwed up a well. In all instances the Ministry of the Evironment has become involved, and all the wells had to be abandoned properly at about $2K per well and new wells drilled at a cost of $8K-10K! Needless to say my clients failed to heed my advice before closing of title and subsequently had to foot the bill! OUch.

Never heard this before. Their comments are suspect without substantiation.

Suggest that the Client request the Well Company produce their comments in writing (on letterhead) substantiating their recommendation.


I feel that is totally ridiculous. I have a DNR Licensed Well Pump Installer license and have been doing Well inspections and water testing for years. Not once at our mandatory continuing ed has this ever been brought up. In the first place samples preferably should be taken from a non-swivel faucet that can be heated to kill bacteria that could be in or on it, so it would not apply anyway. I know many institutions recommend taking samples from the kitchen faucet. There could be some food decay fumes from food left over in a disposal but there should not be fumes from a properly vented P trap.

I have taken hundreds of well water samples. I always heated up my faucet with a torch like Warren. It is recommended by my state.