Hydrofracturing? Rehabilitating a Borewell - Bangalore
Submitted by sasidharp on December 24, 2009 - 09:32
My home is located at HRBR Layout (Banaswadi) Bangalore. We got a borewell dug in August 2005. Here are the details from the report given when the borewell was dug:
76 ft over sandy, 6 to 190 ft MIRock, 190 to 240 ft MI Hard Rock, 240 to 245 ft Water source with boolders, 245 to 270 ft MI Hard Rock. (some of the spellings might be wrong as the report was not clear and I am not sure of the terminology).
Total Depth of borewell is 270 ft. Static water level 90ft and water yield 3600GPH (4inch). While digging borewell, water started gushing from the neighbours borewell (theirs is at 344 ft deep). As they were concerned about their borewell we stopped from further digging.
We have put a 1.5Hp submersible motor with 250ft long pipe. We have also created rain water harvesting around the borewell. We were using the borewell very sparingly. But recently a week back we did not get any water when we switched on the motor. We got the electric connection and motor checked and everything is working fine and the motor mechanic concluded that everything is fine with motor and there is no water in the borewell. We consulted the borewell company.
After an initial investigation they suggested to do Air Flushing to know whether there is any interconnect with other borewells around which dried our borewell. If that is the case we have to go for a new borewell. Otherwise they are saying we can dig the same borewell for another 100ft.
I heard of hydro-fracturing. Will that help in this case? How costly is air flushing verses hydo fracturing? What could be the reason our borewell went dry? Please help me in deciding the next course of action.
Thank you.
Sasidhar.
Comments
1. Rehabilitating a Borewell
Dear Mr Sasidhar,
Before you decide to flush or drill another bore well, you need to check the standing water level in your bore well.
Please do the following:
If your pump a single phase ( 220 volts) or a 3 phase ( 440 volts) ?
If it is a 1.5 hp, single phase pump the ampere drawn will be anywhere 8-10 amps, if it is drawing less current means that either the coupling- motor to pump is gone bad / or the impellers have gone bad./or the pipeline has developed a leak/ or the well has gone dry/
So first try , try to drop a small pebble ( glass marbles) , aprox. 5 mm in diameter and measure the amount of time it required to touch the water . Thumb rule is about 15 ft per second hence if water is around 90 ft it should take 6 seconds to strike water the sound is loud and audible on surface once that is confirmed pour some water say about 1000 liters in the well and see if the pump is functioning properly-minimum 60% of the water that you put in should be pumped out.
If no discharge is got from the pump after putting water in the bore well, get the pump and pipeline out,.
At the same time check the level of water in the bore well by attaching a weight to a Nylon rope and lowering it into the bore well. If the Static water level in the bore well is around 90 ft the problem is with the pump and not the bore well.
Check for leaks in the pipeline, and check the pump assembly, and try it out in a tank of water
If there is no water in your bore well, it is quite possible that the neighboring bore well which is 344 ft is lowering the water table, which is affecting your bore well- the connection with it has already been confirmed by you – water started gushing from the neighbors bore well while drilling
You need not do flushing for that, you could deepen the bore well, as hydro fracturing will not help if the water table is being lowered below the depth of your bore well. Moreover Hydro fracturing will cost as much or even more as compared to deepening of the existing borewell.
From all that has been written above I personally feel that there is some problem with the pump coupling or pipeline and not the problem of bore well going dry, du to lack of water etc.
Best of Luck
Regards
Anil Lalwani
www.wellwaterworks.com
contactus@wellwaterworks.com
2. Confirmed no water in the borewell
Anil, Thank you for the detailed reply.
When we switch on the motor the AMP meter is showing around 4 amps only. We have got the motor out and tried in a water tank and the motor is working fine. So problem with pipeline and motor is ruled out. We consulted a borewell drilling person and he drops a small pebble in and checked. He said looks like the water is far below and suggested to dig a new borewell. He said as there is a interconnect with your neighbours borewell even if we drill the existing borewell it might help. He said if there is a interconnect with another borewell it might not be even possible to drill, to check if drilling is possible or not we can do the air flushing test. Is that correct? The neighbours borewell which is 344ft is working fine. If we drill our existing bore is there a chance that their borewell will get closed or damaged? If the water table interconnect (I am not sure how or what it is technically) is there is it correct that drilling is not possible in the existing borewell?
Thank you once again.
Sasidhar
3. Hydrofracturing? Rehabilitating a Borewell - Bangalore ›
Dear Sir,
It looks like a dipping conduit connection of the fracture between yours and the neighbours bore well towards the neighbours side. Further drilling is possible, may be if you call for a higher capacity drilling rig. Plenty will be available. Once you cross the conduit zone and if you get another spring then the water head will rise above the conduit level and your pump can reach and push the water out. The deeper you drill the higher will be the pressure head and it would / might over come the entry velocity while crossing the conduit zone and you may get sufficient yield to pump out water.
If you are sure of getting such higher yield in the neighbourhood you can go for a new bore well.
By suppose if that bore well also has similar connection then it is a risk. It is better to drill further in the same bore well.
As you informed that you could hear the sound of standing water in your bore well, you can also try putting your pump till the entire depth of the bore well just leaving about 1 or 15 meter gap from the bottom. Some time you may get water.
With best wishes,
A. Raja Mohamed
Geophysicist
Coastal Energy Pvt Ltd - Chennai
bismi123786@gmail.com 097909353
.
A. RAJAMOHAMED AMBALAM GEOPHYSICIST COASTAL ENERGY Pvt Ltd, CHENNAI +919443619352
4. Confirmed no water
Hi! Mr Sasidhar,
Sorry to hear that your water level in the bore well has dropped, possibly due to one more person having tapped the same zone.
Anyway, while you were drilling the bore well the connection between the neighbours bore well had already been confirmed,
All that you can do now is to get a high capacity/high pressure drilling rig and just drill deeper, by flushing nothing much can be achieved- at least nothing regarding whether the well can be drilled or not. Possibly with the newer compressors which have a higher air volume and faster hammers the deepening would be achieved. Try to go down to 350ft only.
It is quite possible that the neighbours well could get affected by this, but it getting total closed or damaged permanently closed is slightly extreme thought.
It is quite possible that while you are deepening the bore well and a few days after that they get muddy water. Earlier there was excess water pressure, but now the formation water pressure has reduced and that is why you are not getting water in your well. There is a good chance nothing would happen to the neighbours bore well even after you deepen your well.
But this is a risk every one has to face, even when drills a fresh bore well.
In your case the choice of space is very limited so it will not make any difference- deepening this well or drilling a new one
All the best
Anil Lalwani
www.wellwaterworks.com
contactus@wellwaterworks.com
5. Nice
Hi Anil,
I like your explanation and your knowledge about bore well water.
Regards,
Vivekanand
6. Is our rainwater harvesting not working
After digging our borewell we created rain water harvesting around the borewell. We dug almost 8 to 10ft deep to create it. Inspite of that our borewell went dry is very surprising to me. The borewell digging person who came for inspection says that our rain water harvesting might be helping neighbouring borewells and not our borewell. Is that possible?
Thank you,
Sasidhar.
7. Hydrofracturing service provider
Mr P. Ganesh of Ayyappa Aqua Solutions provides hydrofracturing services in Bangalore. Unfortunately we are not able to locate his contact information at the moment. The following links give some information related to his work:
http://www.youtube.com/watch?v=qcWup3Eukck
http://indiawaterportal.org/post/2931
http://www.hindu.com/pp/2009/04/18/stories/2009041850030300.htm
8. Rehabilitating a Borewell - Bangalore
Dear Sir,
Hydro fracturing is not a solution to your bore well.
Please follow Shri. Ani Lalwani Sir's recommendation.
As suggested by him, please deepen the bore well to a maximum depth possible by the drilling machine may be up to 650. You have provided the pipe on to 250 feet the water level might have gone done below due to pumping by your neighbours. The extention drilling will automatically flesh and clean your bore well.
My past experience indicates that 3600 gallons per hour yielding bore well can not go dry all of a sudden. Please follow his advise.
With best wishes,
A. Raja Mohamed
Geophysicist
Coastal Energy Pvt Ltd - Chennai
A. RAJAMOHAMED AMBALAM GEOPHYSICIST COASTAL ENERGY Pvt Ltd, CHENNAI +919443619352
9. Dear Sasidhar, What do you
Dear Sasidhar,
What do you mean by "we created rain water harvesting" ? How much is your catchment area ?
Chetan Pandit
National Water Academy
10. the way we created rainwater harvesting
Dear Chetan Pandit,
The catchment area is our RCC terrace around 900 to 1000 sqft. We dug around the borwell about 8 to 10ft deep and 5 to 6 ft wide , and filled it with multiple layers of gravel and sand. The rain water drain pipe directly runs into this. We have put mesh at the starting of the pipe.
Thank you,
Sasidhar.
11. Average annual rainfall in
Average annual rainfall in Banglore is 867 mm, say 870 mm. If you are able to catch 60% of it, and on a 1000 Sqft terrace, the total catch would be about 48 m3, or 48,000 liters. Let us assume that all of it goes in to your borewell and is available to you and you alone. How long will that last ? Depends on you daily pumping. You have mentioned a yield of 3600 GPH, that is 16,000 LPH. So even if you run it that rate for just one hour every day, the total harvested quantity will be finished in just 3 days. If you run it that rate for just 15 minutes every day, it will last 12 days.
But the bigger problem is, the assumption that all the harvested water is available to you and you alone, is grossly incorrect. In your drilling log you have mentioned layers of hard rock above your pump level. Most likely, the harvested water is percolating some depth and then, upon encountering impervious strata, is flowing horizontally. The case study points to certain deficiencies in understanding of urban rainwater harvesting.
The quantity harvested from a typical middle class roof area is not much, and does not make any significant difference to the bore well yields, particularly deep wells that penetrate the hard rock. As bore wells get deeper and deeper, the water is likely to encounter impervious strata and flow horizontally. Unfortunately, it is considered blasphemy to say so. So, like the proverbial emperor’s new cloths, every one goes on pretending that roof top rainwater harvesting is a magic bullet solution, and the myth persists. All this is not to dissuade you from continuing with rainwater harvesting. Some one else will benefit from what you are doing. This is only to put your expectations on a realistic footing.
Chetan Pandit
12. Rainwater Harvesting
Dear Sasidhar.
I would like to add to the comment made by Mr Pandit regarding the fficacy of rainwater harvesting.
I totally agree with him that rainwater harvesting is not a "magic Bullet Solution" for an individuals water problems.
But that is what is being projected by most government agencies and people who have been using this to make a profit for themselves., and you are not the only person who has got carried away with prevailing misconceptions regarding its benifits.
At the same time, I would say that with the increase in surface run-off that is being generated due to urbanization, and also the increased stress on the groundwater by individuals to meet their daily water requirement. Rainwater harvesting is more of a social obligation for everyone who is tapping groundwater or modifying the natural set-up.
This is to ensure that the natural hydro geological set-up is not disturbed and one makes provision for some sort of rainwater harvesting system in place to help reduce surface run-off ( which has its own problems) and also to ensure that there is recharge to the aquifers , which may be tapped by some one downstream.
while doing this one has to take care that one does not land up contaminating the groundwater system, if there is a certain amount of excess recharge to the system, it will be rejected by way of increase in base flow etc... if not it will help in supplementing the depleted aquifers.
Improperly designed Rainwater harvesting system ( urban or within a watershed) can lead to waterlogged conditions and increase in soil salination, aquifer degradation ( quality) and other associated problems.
Finally, rainwater harvesting does not only mean diverting rooftop water to charge the groundwater.
If you want to get direct benefit from it, divert it in to a storage tank of substantial size and only the overflow during times of heavy precipitation can be diverted in to charge the groundwater.
Naturally this done not really help you out in times of scarcity or summer months, but then diverting rooftop water in the rainy season to your bore well also does not remain there in there for you use in the summer months- groundwater is always in a dynamic state which means that it is flowing .
With kind regards
Anil Lalwani
www.wellwaterwork.com
13. Thank you all
Thank you all for the replies and suggestions. I agree with the comments on rain water harvesting. And coming to my borewell I will go ahead with re-drilling the existing borewell.
Regards, Sasidhar
14. Hello Sir I saw your message and got your email
Hello Sir
I saw your message and also got your email.
Sir I have one doubt, can we drill a bore well 1 feet outside of my house on the road side as its a built house and we face lack of water. Our residence is in Bangalore.
Regards
Mehraj
15. Water source for new bore well in Bangalore
Sir,
We drilled the bore for 450 ft deep with water source at 150 ft (with Rock/ stone formation till 450 ft) and water storage level is at 220 ft. There is no silt formation.
I want to know:
1. Type of pump and capacity (HP)
2. How much water will be strored at all the time in the bore?
3. Is it good bore? (As I need to invest around 40,000/- on piping and pump etc.,)
Please advice,
Rao
16. Have not received any reply in this matter
Dear Sir,
I have not received any reply in this matter. Please do the needful and comment on this issue. I am curiously awaiting your valuable advice.
Thanks and regards,
Raghavendra Rao H S, 9845805944
17. Very less flow of water in borewell
Dear Sir,
We are constructing a new house in Banashankari 6th Stage near Nice office. Bore well was dug in May 2011 for 600ft. In the beginning water was sufficient for our usage. But after two months water has suddenly stopped. Water came after two days with very less pressure. The flow was only for 20min. And again it stopped. We have contacted the bore well motor supplier and they said that the water has dried up. But there is still flow of water of about 100lts only daily. Please guide us on what we should do.
Thanks and regards,
Chandrashekhar M
18. Borewell collapse at 645 feet
Hi,
My house construction (in 30x40 site) has started and now its at the foundation level. We had drilled a borewell and the information is as follows,
Borewell location : K.R.Puram (Mahadevapura), Bangalore East
Drilling time: Mid November, 2011
Depth of borewell : 650 feet
Depth of 6.5 ” casing : 80 feet
Depth of 10" PVC Casing pipe: 10 feet.
Yield data - I yield: 640 feet, 2.5".
On further drilling, boulders were found at 645 feet. and we continued to drill till 660 Feet.
It was meant to be used during the house construction. Now, before inserting pump we checked with a camera and found that the well has collapsed at 645 feet onwards and the depth of water we have is just 5 feet. Also looks like water source is connecting to another borewell, as water is not rising above 640 feet though we had 2.5" to 3" water during drilling.
Can you please advise whether drilling for another 100 to 200 feet will help?
Is it possible to install PVC filter pipe from 640 onwards using any method after re-drilling for another 100 t0 200 feet?
Any solution will be greatly appreciated.
Regards
Mahendra S
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