Transcript Slide 1

WASH Cluster – Groundwater Pumping
GWP
Groundwater Pumping
Session 3
Pump Selection
GWP3
1
WASH Cluster – Groundwater Pumping
GWP
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
GWP3
2
WASH Cluster – Groundwater Pumping
GWP
Aspects to consider
Technologies have to be:
 Technically feasible
 Environmentally
sustainable
 Institutionally
supportable
 Economically justified
/viable and,
 Socially acceptable
GWP3
3
WASH Cluster – Groundwater Pumping
GWP
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
GWP3
WASH Cluster – Groundwater Pumping
GWP
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
GWP3
WASH Cluster – Groundwater Pumping
GWP
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
GWP3
6
WASH Cluster – Groundwater Pumping
GWP
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.
GWP3
7
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
GWP3
GWP
WASH Cluster – Groundwater Pumping
GWP
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
GWP3
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
9
WASH Cluster – Groundwater Pumping
GWP
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.
GWP3
WASH Cluster – Groundwater Pumping
GWP
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.
GWP3
11