Well Shocking Multiple Times

[SLOBuds]

I got a water test from the county which showed coliform and ecoli. Then I shocked the system with chlorene and cleaned out everything throughly - followed the shock procedure strictly.

Re-test shows coliform and no ecoli. The county guy says 'that's better, but not good - no drinking yet.'

I read that multiple shock treatments can help if not fully repair the well. One document said that 3 treatments might be needed to affect the correction.

This is a pretty big effort to get done. Before I actually go there, I'd like to know if it will lead to success.

Any opinions?

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] One thing that I've learned about this is that "contact time" can vary as the water flow in and out of the well. If the well is punched into a moving aquifer, OR.... if a slow-moving aquifer is actually the source of the contamination it can be tough to get a clean well. In mountain communities it isn't a bit uncommon for septic tank discharge to follow on top of a clay layer and show up in a domestic well. If further treatments show some gain, then I would wait for a while and then test again to see if the re-contamination is from the water source and not some problem with what was standing in the well. [img]/forums/images/icons/tongue.gif[/img]

[egon]

best be doing it again and again and then take samples on a regular basis.

You should also look into how the well is completed and where the contamination could be coming from.

There may be more involved than just a shock treatment. [img]/forums/images/icons/frown.gif[/img]

Egon [img]/forums/images/icons/grin.gif[/img]

[SLOBuds]

CJDave - then do you believe that the shock treatment can be done once or a few more times for, potentially, better results?

Egon - I am not at all versed in groundwater attributes. But when I talk with my well men, they make me believe that it is near impossible to tell for certainty what is going on down there. And they also say that it is hard to know where to look. That many different factors can cause the well to be that way.

If there is a fair possibility that multiple shock treatments will clear up my water, than I will do that. The shock treatments are many more times cheaper to do than trying to find another hole to drill!

[RichZ]

Something else to consider, is whether you re-contaminating your well. One of the most common causes of well contamination is through backflow on hoses. For example, if you have a stock tank (livestock drinking container) and you fill it with a hose, if you leave the hose submerged in the tank, and turn off the water, you can create a backflow where the stock tank water will be sucked back into the pipe, causing your whole water system to become contaminated (since most stock tanks eventually get contaminated with droppings). Make sure that isn't happening, and that you have no cross connections that could contaminate your system.

[egon]

Your well drillers reply are reasonable for an old well.

Treat, test, treat til you get positive results. If not start to consider a new well but do try and determine the aquifer quality from other wells surrounding you if that is possible.

You may wish to contact knowledgeable people on treatment systems also.

Please note, I am not competent to give positive advice on wells and treatment so take all my comments as opinions only.

Egon [img]/forums/images/icons/grin.gif[/img]

[SLOBuds]

Thanks again Richz and Egon.

Richz - there is a backflow preventer on the outflow line and it (surprisingly) does operate. On top of the fact that there is an airgap between well line and holding tank which adds that layer of security too.

Egon - this is the puzzling part. None of the other wells in my area have this problem. So I am a LITTLE bit hopeful that it is not the aquifer itself.

This is very very frustrating. Several of my friends have told me that it must be nice to have 'free' water. I reply that our water delivery has been much more expensive in the country than it ever has been in the city with city-provided water.

[egon]

Free water he he he.

Perhaps relate to the friends the cost and effort it takes to have "Free Water"

This is something like burning "Free Wood" for heat! [img]/forums/images/icons/grin.gif[/img]

If all the surrounding wells are good just keep shocking and testing. Check your well area for surface runoff that may pass by the well or other such things.

Last spring our daughter bought a house with attached well. The prepurchase water test showed coliforms. After shocking all was good and follow up tests were okay. It would seem the coliforms arrived when the previous owners had a pump replaced. As there was no pitless adapter, just a concrete cased hole in the ground an adapter had to be added prior to purchase. The cost of installation was split between owner and my daughter. This is a jet pump system on this well.

Which reminds me to remind the daughter that another set of tests may be in order! [img]/forums/images/icons/grin.gif[/img]

Egon. [img]/forums/images/icons/grin.gif[/img]

[RichZ]

I'm glad that you have the backflow preventers, and that they actually work. Most homes don't have them.

We have one well for our house and our farm. We are a commercial goat dairy, so our water supply is tested several times/year by the state. Invariably, one of my farm workers, who are kids, forgets, and leaves a hose in a stock tank, and recontaminates our well. After having to shock and re-test numerous times, I finally bit the bullet and bought an ozone disinfection system for our well. It cost about $1000, but my water is always free of bacteria of any sort now. The volume of water a typical home uses is much less than we use, so you could have good results with a much cheaper system.

[SLOBuds]

I have ultraviolet on one of the houses at my place. The water is turbid after rain, which reduces the effectiveness of the ultraviolet treatment.

Ultraviolet equipment have stipulated levels of turbidity which may not be exceeded.

Thank you both for suggestions. I am going to shock treat a second time this weekend.