Muddy Bore Water - troubleshooting : Costs Involved ? Bangalore
Submitted by Shalini Nair on December 4, 2009 - 17:32
Hello,
Our borewell is sited at Cox Town, Bangalore with a depth of 215 ft and was dug around ten years ago. The well was being used for residential purposes and was a trouble free source of potable water till a month ago.
Of late the water is muddy, with thick layers of clayey soil being deposited at the bottom of our overhead tanks.
Roughly around the same time our water turned muddy, our opposite neighbours had dug a borewell to commence construction. The drilling had to be aborted within a couple of hours due to a huge grating sound ( apparently due to the use of high pressure air compressor) and damage to several houses nearby. There was a crack right across the road, damage to the BWSSB pipes beneath the road, cracks in several of the buildings around, and some resettling of soil as door, gate, window alignments were disturbed. Just to the right of our borewell, the compound wall had totally crumbled and was rebuilt.
I would like to know whether the digging of the neighbour's borewell could have caused the disturbance to our water source and whether they could be held responsible along with all the other damage caused by them?
Secondly,several borewell specialists have been consulted and opinions differ. We have had suggestions ranging from flushing out the borewell, to allowing the water to run to the garden until it becomes clear to converting the borewell into a tube well by inserting a slotted casing with gravel packing, scanning the borewell and even pouring some chemicals in to clear the water.
We are confused by the options and would like to seek the help of the forum to deduce the right course of action.
Advice regarding the costs involved in remedying the situation would be welcome!
Thanking you,
Shalini Nair
Comments
1. Dear Shalini Nair, In hard
Dear Shalini Nair,
In hard rock area, the construction of borewell adjacent to the existing borewell may cause problem due to air pressure passing through the fractured formations.
At the present case it is suggested to clean the existing borewell and lower a low capacity pump to overcome the problem of muddy water from the bore.
With regrads,
D. Chakraborty
Scientist
Central Ground Water Authority (CGWA)
New Delhi
2. Dear Shalini Nair, IF your
Dear Shalini Nair,
If your bore well has suddenly started giving muddy water, it has started after the major damage observed in the nearby areas.
I feel that there has been some major settlement/soil creep in the area reason for which could be only decided after detailed on-site investigations, but the muddy water in your own bore well could be a result of your casing pipe getting damaged due to this and the subsoil water has got some avenue to enter the well.
No amount of flushing is going to solve this problem, if the damaged casing pipe cannot be repaired in some way.
Regards
Anil Lalwani
www.wellwaterworks.com
contactus@wellwaterworks.com
3. Muddy Bore Water - troubleshooting: Costs Involved? Bangalore
4. Muddy Bore Water
Dear Sir,
As pointed out it is site specific problem. Field study and assessment is required for ascertaining the cause,effect and providing solution to your query.
But the damage caused due to the abandoned drilling by one of your neighbour though caused damages narrated by you, but it is unintentional.
Hence, I solicit you to better think about getting solution to your problem.
Your site and the neighbourhood looks to be situated in a highly crumbled / fissured and sheared Geohydrological set up. May be the heavy duty DTH rig might have come across some hard intrusive, which might have originally caused the crumbled / fissured or sheared effect. And when the bit and hammer struck this hard formation, with a constant frequency as per its design, the frequency of the hammering action created sound wave that in turn might have effected the resonant reverberation and the heavy pressure might have propagated the mechanical energy in all direction.
This might have caused the tiny cracks to open further and gave way for such effects narrated by you. May be the designed engineers or planners, without any geo-foundation studies might have constructed the structures.
One such opening might have got connected to your bore well, along the highly weathered or sheared, soft water bearing formation. When the recuperation takes place either during pumping and or after, invariably this newly evolved conduit is carrying the clay colloidal mud into the bore well. This is only a guess.
To my experience it is difficult to filter this colloidal mud entering into your bore well at this juncture by converting into tube well with slots and encircling tiny pebbles, though you may be able to locate the entry zone by bore well scan or video logging.
You may use the same resources to drill a new bore well along the same fracture strike line and by sealing the soft zone and allowing water to enter from the deep rocky portion. Since the area looks to be or seemingly a disturbed one there is most likelihood of getting ground water from deep strata.
With best wishes,
A. Rajamohamed Ambalam
Geophysicist
Coastal Energy Pvt Ltd.
Chennai - Mobile; 097909353 bismi1234786@gmail.com
A. RAJAMOHAMED AMBALAM GEOPHYSICIST COASTAL ENERGY Pvt Ltd, CHENNAI +919443619352
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