Well water 250 nm clay - how to fix it

[alternety]

I have a residential well with a suspended solids problem. I believe the solids are at 1.1 mg/l. I have had differing results from multiple water testing. A sample was finaly provided to a university and they did an x-ray crystalography study of the sample. I gave them a gallon of water and they had problems getting a large enough sample of the contaminant to do a proper test. They determined that the particle sizes are about 0.25 microns. The material is highly reflective/refractive and makes the water look murkey. This is evident in a container as small as a 1 gal bucket. It spots things. Theeir best guess from the tests is that Kaolinite is the major component. There might also be traces of Bentonite which would probably indicate some leakage around the well because that is what is used to seal it from surface water.

I am going to need a filter for iron and manganese as well. I will prpbably use a Birm filter for that.

I need to get rid of the clay. It is too small to use a mechanical filter for the whole house. Floculation is a possibility but one of the water testers tried this to analyze the sample and was not real successful acording to him.

In trying to figure out where this is comming from; it could be from the interface between the well casing and the solid rock that starts 30' down. It may also have been caused by hydrofracting too close to the surface of the bedrock.

I would appreciate some help on cleaning the water.

 

[semo]

Is this a new well or an existing well that has recently developed problems.

If the later, has the casing been examined to determine that it does not have a hole.

I don't know where you are from so I dont' know the cost of a residential well in your area; but, the fix could be more than a new well.

Flocculation will require treatment volume and chemical addition which I don't think you want to mess with in a residential situation.

It is possible that either of your possibilities is the source. Some testing needs to be done to determine this. One means is to pump the well at various levels using packers. Then if the level of the contaminants is found, grout that source off.

 

[alternety]

Additional info.

The well is "new". It was drilled more than a year ago but has not been put into service because the house was not done. I have taken many thoushands of gallons from the well to see if it would clear up. It has not.

The well is 605 ft deep in solid rock. Cost for a new well nad probably hydrofracting again would be in the range of $20K I am also out of accessable areas that do not conflict with the required distance from the septic system. If surface cracks are the problem, I would have to get further from the existing well to avoid tapping that water source. The hydrofracter said the cracks can extend hundreds of feet.

I am not sure how to actually do as you suggested in pumping at differrent levels. I do not understand how you would do packing at various levels. At the very least I will need to get a well drilling rig (or something else out to handle the pipe.

 

[bimr]

Semo is referring to a different type of well construction that you do not have. If you had included more information on your well construction with the original post, he would not have presented those ideas. The type of well that you have is more prone to water quality problems because you do not have the filtering action of the soil as in a typical well driven into an aquifer.

Like politics, all well drilling is local. Have you talked to the well driller about his experiences with this type of well and water treatment? Have you tried a water filter on this? You can probably get a residential water treatment vendor to demonstrate his products on your water.

Trying to flocculate a small flow application like this is not practical and will be a disaster. If you put a standard water filter on this application, it will probably take out most or all of the clay. If it does not, then you can go to cartridge type filters with a smaller micron rating. You can stage the filters with different micron ratings in series so that a single filter will not blind.

 

[cub3bead]

You will need a pretty tight filter to catch 0.25 micron stuff!

Sounds like the driller used drilling mud rather than air or water to remove the cuttings. Have you talked to the driller about options to salvage the well? Have you tried producing the well and seeing if the clays will clear?

 

[alternety]

The driller used water.

The driller has no solution.

Thousands of gallons have been taken out of the well. Initially the water looked like milk. It reached what I am getting now, and does not seem to be further improving with use.

 

[semo]

That is a pretty good price for a residential well, but trying to correct the well could cost as much again with little or no results.

There are a lot of things that are location dependent with wells and I don't know your area; but, here are some thoughts on "trying" to fix the well.

The drill log should at least tell you were your water sources were (voids) prior to the fracturing. The driller should also have records showing the volume of water obtained as he was blowing the well to remove the cuttings. He should have used a weir on the discharge water during drilling. These will help tell the location(s) where the water is coming from.

A camera inspection of the well can also tell you the void locations that can be possible production sources. You might even be able to pump with the camera in the hole and see contamination sources.

In easy terms a packer is an inflatable ring that can be placed on the pump column pipe. When lowered to a predetermined level, it can be inflated between the column pipe and the hole wall sealing off the area above and/or below the pump intake.

With the log data and one or multiple packers you can pump from various levels to see if you can find the source of contaminants. If one area is determined to be the source, it can possibly be isolated.

This will not be cheap as it involves time pumping and the specialized equipment. I don't know your driller; but, around here most residential drillers do not have the equipment or expertise to do this. Your driller might be one of these and you need to talk to a GOOD reputable larger driller with experience on similar problems in your area.

You also might not find a single or multiple source that can be isolated. It might just be what that well produces. Good water quality rock wells are hit and miss in a lot of locations. I even know of wells in some areas that require pump off at high rates for 9 months to a year before clearing to acceptable levels.

If a good driller does not have an answer, I agree with Bimr that staged filtration might be your best option. It will probably have a lower cost.

 

[bimr]

Sorry, I skipped over the part about the .25-micron particle size.

I don't think there is anything further that you can do to improve your well. Hydrofracturing is not used unless the well yield is poor. I have seen other wells where the yield is so low that the well casing itself is used as a collection reservoir. The well casing will fill up over the day and be emptied when the pump turns on.

You need to think about filtering the water to remove the .25-micron particles. That is best done with what is called a microfilter. Zenon is marketing one with Maytag at the present time. If you your iron and manganese concentrations are not high, you may be able to aerate the water and remove the iron and manganese with the microfilter as well.

Am ultrafilter or nanofilter will also work. These products are normally used for larger municipal installations and you need to find a vendor that is dealing with the household market. A good start is to talk to Zenon.

http://www.wellmanager.com/wellmanager_applications_hydrofracting.htm

http://www.epa.gov/safewater/privatewells/basic_drilled.html

http://www.uri.edu/ce/wq/has/html/Microfiltration.pdf

http://www.maytagwater.com/

 

[alternety]

Thanks bimr. The Zenon reference looks real promising. The Maytag system has rather skimpy specs online It does not give me the impression it uses the same flushing and vacuum processes of Zenon system but I can't be sure. I will contact them as well. There are no area dealers. I am North of Seattle.

 

[alternety]

The Maytag systems looks like what I need. Filters to 0.04 Microns, back-flushes. 4.5 GPM, 5-10 year filter life. Two problems. 1 - expensive, but I have found no alternatives. 2 - Needs dealer testing at installation for there to be any warranty. Closest US dealers Arizona and California and I am in NW Washington. Zenon won't sell direct because of their marketing agreement with Maytag for North America. I am still working the issue.

 

[alternety]

Does anyone have the PDF file of the manual for the Maytag 4200 whole house water filter? It is made by Zenon. I need to see what I am getting into before I buy it and information is like pulling teeth.

 

[alternety]

Just a follow up.

I got a Zenon filter. Slicker than snot on a doorknob.

Takes all the garbage out.

 

[Dubliner]

Hi Alternety

Congratulations on sorting out the problem, but here's a thought to consider: if the clay particles are coming from the 'bentonite' seal in the borehole annulus then this suggests to me that (a) the seal is not a good seal and (b) water is flushing through the 'seal' and bringing clay particles in suspension.

If the flushed water is coming from a higher horizon then might water quality become a problem in the future? (microbiology, contamination, etc).

I don't mean to rain on your parade, just felt it was worth pointing out because your solution fixed the symptom but not the cause.

Anyway, all the best and good luck.


Adam Beresford-Browne
Zenith International Ltd
zenithwater.com