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The electricity supply to Pabal and
Vigyan Ashram is erratic. Daily 8-hour
power cuts tend to occur in two 4-hour
blocks during the day but additional
cuts are common; for example bad weather
has caused a 15-day power outage in
the recent past. Vigyan Ashram has noticed
that power cuts in general conform to
a regular pattern. The general pattern
is:
Monday 0900 - 1300, 1700 - 2100
Tuesday 1100 - 1500, 1900 - 2300
Wednesday 0500 - 0900, 1300 - 1700
Thursday 0700 - 1100, 1500 - 1900
Friday 0900 - 1300, 1700 - 2100
Saturday 1100 - 1500, 1900 - 2300
Sunday 0700 - 1100, 1500 - 2100
There are also occasional power surges.
Modern well construction is done
in three distinct stages. Firstly
a hole is cut of diameter 11-15ft
to a depth of normally 10ft, and then
a narrower shaft is dug on the same
centreline to a depth of up to 35ft
by either crane pile-driver or blasting
(dependant on the geology). The reason
for the change in diameters is to
allow the excavation equipment to
be positioned and to operate below
ground level. The last stage is to
remove the excavation equipment and
brick up the top 10ft or so of the
well to give a uniform diameter all
the way down the well.
A 35ft depth well will take approximately
1½ months to complete at a
cost of 1000-1400 Rs./ft depending
on rock hardness. Greater depth and
rock hardness leads to a greater cost.
Smaller diameter wells situated in
homes are not normally done by modern
machines.
An electronic system exists already
at Vigyan Ashram (a local NGO) for
the assessment of well sites and is
in active use, though it has limitations.
Mr. Anil Gadhe operates the current
system and explains that it measures
the resistivity of the soil to deduce
its water content is in use. The electrical
circuit was devised in 1983, and 2405
assessments of potential well sites
had been conducted as of 16 July 2005
at up to 200km away. The general test
procedure involves inserting two steel
pegs 30cm into the ground at varying
distances apart and passing current
through the earth to measure its resistivity.
The current can pass as low as 150
ft below the surface.
However the device is not without
its limitations. The test will produce
inaccurate results in wet weather
or when an electrical charge is nearby
(i.e. a pylon). The fieldwork, which
is only done in the dry session, takes
2 hours to perform and then the data
is manually calculated, plotted and
analysed - which is open to human
error. The accuracy of the assessment
conclusion is approximately 85-90%.
Please refer to the engINdia Final
Report for information about the geology
of the region.
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