Clearing the boulders blocking the borewell - Please suggest the best course of action

27 Oct, 2010

Hi,

I ran into a problem recently and seeking your valuable advice regarding this. Any help/guidance is greatly appreciated as I am a layman in this area.

I have got a 6" borewell dug up in June 2010, for an independent house being constructed. There were 2 water sources found at 400' and 560'. Total depth of the well is 650'. I have got the casing done till 151'. The borewell company told me that it's rock after that and didn't put anymore casing. Water yield was told to be 2". In July '10 I've got a 3HP motor installed and using the water from then onwards. Saw small black particles (assumed to be mud) for first couple of weeks and then everything was normal. In mid Sep '10, motor stopped pumping water up. Occassionally, it used to pump up water, but very slowly. Motor company inspected & told me that the motor got jammed and tried pulling it out. They said, it has got jammed and called the other expert team to lift the motor up. Upon inspection, the motor is completely gone due to the silt got struck in it. They got it repaired (almost replaced) and tried putting it back in.

It stopped going in after 187' and then I got the camera test done. Camera test revealed that there is a breakage in the casing pipe around 39' and we thought that it's the cause for silt getting into the well. This test confirmed that there are boulders blocking the well completely at 187' (camera was not going in further). Now, pls suggest me the best course of action:

1. Get the boulders at 187' broken down by the GI pipe method. As per them, it may or may not be successful, depending on the size of the boulders. Also, my concern is, what if it gets struck anywhere between 187' and 650'?

2. Get the bit flushing done. That company guy told me that it's not possible for me to get this done as the roof clearance at that area is only 9' and it seems he needs around 11' height of 2'x2' area. Is there an alternative for this?

3. In either of the above options, I was suggested to have 5" slotted PVC casing for all the 650' length. Is it safe to go only till around 200' and hang the casing to the 6" GI casing that I already have?

4. What is the way out, if the 5" PVC casing drops inside accidentally (if I put it only for 200'), at a later point of time?

5. Is it guaranteed that I won't run into the similar/anymore issues once the 5" PVC casing is done? I'm concerned about it as I found a crack in the 6" GI casing itself.

6. Dump this borewell and get another one dug up - I don't prefer to do it as I have already spent lakhs of rupees on this and as well there is no guarantee that the similar problem won't recur at alternate location.

Thanks,

harish