Transcript Slide 1
WASH Cluster – Groundwater Pumping
GWP
Groundwater Pumping
Session 3
Pump Selection
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WASH Cluster – Groundwater Pumping
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Involving communities in pump
selection
What role should users have in deciding water
supply system?
In groups discuss the following points
Areas for involvement
Possible limitations
Benefits of standardisation
two scenarios;
1. Community pre-disaster
2. Post emergency situation
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WASH Cluster – Groundwater Pumping
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Aspects to consider
Technologies have to be:
Technically feasible
Environmentally
sustainable
Institutionally
supportable
Economically justified
/viable and,
Socially acceptable
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WASH Cluster – Groundwater Pumping
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VLOM
• Village Level Operation and Maintenance
• Pumps should be:
– Easily maintained by village caretaker, requiring
minimal skills and few tools
– Manufactured in-country, primarily to ensure the
availability of spare parts
– Robust and reliable under field conditions
– Cost effective
– Choice by community of when to service
– Choice by community of who will service
– Direct payment by community to the caretakers
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WASH Cluster – Groundwater Pumping
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Hand, Motorised or Alternative
Energy?
Hand
Motorised
Alternative
Advantages
-VLOM
-Reliable
- Very easy to draw
water
- Often quick to
implement
- Isolated rural
areas have no
access to energy
services
Disadvantages
-Difficult to draw
water, especially
from larger depths
-Water can be
drawn when it is
needed.
-Higher chance of
the mechanisms
failing or needing
repair
-Repair requires
skilled labour
-Effect on the
environment
-Cost of fuel
-Often very
expensive
especially PV
-Solar can only
pump during the
day – need to store
water
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WASH Cluster – Groundwater Pumping
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Choice of technology
Handpumps
For smaller communities with 50-1,000 inhabitants
handpumps are the most economical choice
Electrical pump from Grid
If power is reliable, and the community has a population of
about 2,500
Diesel Pumps
For a community with 1,000 to 2,500 inhabitants. However,
running cost is 20%-25% higher than electrical pump
Solar Pumps
For communities with 600 to 1,200 inhabitants, small solar
pumps are cost-effective when pumping lift is not high
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WASH Cluster – Groundwater Pumping
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Choice of Handpump Technology
The most important factors for stress on a handpump
are the number of users and the pumping lift, both
factors increase the workload exponentially.
If the groundwater is aggressive, pumps have to be
corrosion resistant.
Depending on the size of the user group, family pumps
or community pumps should be used.
Shallow wells with less than 7 metres water table
allow suction pumps; up to 15 metres lift direct action
pumps might be used, deep well pumps can cover the
complete range but are expensive.
Easy to repair pumps allow village level maintenance.
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WASH Cluster – Groundwater Pumping
Range of Lift
•
•
•
•
•
Suction Pumps: 0-7 metres
Low Lift Pumps: 0-15 metres
Direct Action Pumps: 0-15 metres
Intermediate Lift Pumps: 0-25 metres
High Lift Pumps: 0-45 metres or more
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WASH Cluster – Groundwater Pumping
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Yield
VLOM
8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80
User group
4
Corrosion
resistance
Lift (m)
Application Range of the most common Handpumps
No. 6 Handpump
Jibon Pump
Tara Pump
Malda Pump
Nira AF-85
Rope Pump
Walimi Pump
India Mark III - 63.5mm Cyl
India Mark III - 50mm Cyl
India Mark II Pump
U3M Pump
Afridev Handpump
Pamir
Indus Kabul Pamir
Bush Pump
Volanta Pump
Vergnet Hydropump 60
Legend:
Recommended
Range
Possible
Range
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Fully resistant
150-300 persons
Easy to repair
Affected
50-150 persons
Requires skills
not resistant
Family Pump
Requires tools and skills
High
Yield
Medium
Yield
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Solar power
The high initial capital cost, 4 to 5 times higher than a diesel
installation, is due to the high cost of PV panels. The power
requirement is the product the pumping head and the water flow,
expressed in m4/d (m3/d x m). For applications of less than 200
m4/d handpumps are more economically viable.
For heads of up to 50 m and about 800 m4/d, solar systems are
viable. From the economic point of view, large solar systems are
less advantageous. PV systems become uneconomical compared to
diesel systems at a range of 2,000 to 4,000 m4/d.
PV power systems do not emit substances threaten human health
or the environment.
The Energy Pay Back Time is the time in which the energy used for
the production of a module is compensated by the electricity
generated with it. The EPBT for PV systems is presently about one
to two years.
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Security and Maintenance of Solar
Theft and vandalism of solar modules is a threat to solar PV
systems. It is imperative to involve the community fully and to have
complete ownership.
Fencing off the system prevents theft. Fences should be 2 metres
high, with barbed wire, and have gates with proper locks.
Communities might decide to employ a night guard and pay his
salaries.
O&M by the community consists of wiping panels and keeping the
water points clean.
For maintenance and repairs, a maintenance contract with the
supplier to provide the necessary back up may be signed. The
technical back up should include spare parts supply. Long-term
contract with a reputable, well established company are needed to
achieve long service life of up to 20 years. Contracts should be
endorsed and regulated by the government department in charge.
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