The Bucket Pump
The bucket pump is a simple water
lifting device designed by the author in 1994
mainly for low-yielding boreholes, not
appropriate for the installation of Mark II and
Mark III pumps, widely used in Maharashtra. The
main concern in designing the bucket pump was to
keep it as simple as possible in order to
minimise maintenance problems (all mechanical
parts were excluded) so that the users would not
depend on outside help. The bucket pump has four
components: the pump stand, the windlass with
handle, a 5 litres cylinder with a foot valve,
and a wire-rope; the platform completes the
installation. The length of the wire rope ranges
between 30 and 60 ft in accordance with the water
level depth and well yield. Altogether 40 bucket
pumps have been installed in the past four years.
|
 |
This simple tool is becoming very popular in the project area; users call it “Tino’s Pump”
(Tino is short for Costantino, my first name). Some Volunteer organisations (NGOs) are
now introducing this pump in other districts. It can be manufactured by a local mechanical
workshop at a cost of 100 dollars only. Villagers consider it a reliable, improved
version of their traditional way of collecting water by rope and bucket from open holes.
A villager, preferably a couple living close to the well site, is selected as responsible for
the well maintenance and receives a tool-box for preventive maintenance and small repair.
The tool box contains small clamps, pliers, grease, a fishing hook and nylon rope to fish
the cylinder in case it drops.
Bucket Pump Performance
The bucket pump, originally was conceived for low-yielding boreholes. Subsequently, its
use was extended to boreholes drilled in remote villages, specially those not accessible
during the wet season for the maintenance of other type of pumps. After having run a
number of bailer tests, using a properly designed cylinder, it has been possible to estimate
the amount of water that can be withdrawn under different hydraulic conditions. The
results of the bailer tests obtained under sustained water withdrawal, are outlined below:
1.Poor yielding boreholes (less that 500 litres per hour), with water levels between 20
and 30 ft can supply 150-200 litres per hour.
2.Boreholes with good yield (between 500 and 1000 litres per hour) and water levels
around 30 ft may supply 300-400 litres per hour.
3.High yielding boreholes (more than 1000 litres per hour) with water levels around 15 ft
may supply up to 800 litres per hour.
With the increased knowledge about the performance of the bucket pump in the past
years, its use has been extended to a wider range of boreholes having different hydraulic
conditions. The yield of the 40 boreholes equipped by bucket pumps in the past 5 years
ranges between 25 and 42000 litres per hour. The installation of the bucket pump in high-
yielding boreholes is justified by the small size of the villages, generally less then 100
people, or by the possibility to replace the bucket pump at the end of the wet season with
an irrigation pump during the dry months, if conditions are favourable.
The bucket pump can be installed in boreholes as shallow as 60-70 ft (and even shallower
if their yield is high), and in boreholes with yield as low as 25 litres per hour during the
driest months of April-May (during the other months well yield is generally higher). The
exploitation of such very low-yielding boreholes can be appropriate for small hamlets if
water is used for drinking and cooking purposes only. For the other water requirements
(bathing, washing animal drinking) villagers would continue to use the existing water
sources. Water withdrawals from these low-yielding wells generally takes place in the
morning and in late afternoon and can satisfy the needs of nearly 100 people, considering 5
litres per person per day.
|