Section 17

Handpump Maintenance

Since a new well is expensive and important to a communities well-being, the well and surroundings should be regularly inspected to ensure that:

The well is fully accessible to all users and is fenced off to prevent animal access.
The sanitary well cap is securely in place and watertight.
No openings have developed in the well casing.
The cement pad is not cracked.
The ground surface is sloped so that surface-water drainage is directed away from the well.
Debris is not floating on the surface of the well water.
The well yield is has not declined over time (see Appendix G-11).
The pump is still working efficiently (cup leathers in the pump cylinder need to be changed every 6-24 months. To learn how to make your own cup leathers, see Appendix L.
Ensure that the well is chlorinated (Section 15) EACH TIME the well is opened and the rising main pipe is removed! For details on inserting a cylinder back into a well, see Section 14.
That all screws and connecting bolts on the pump are tight.
That the wooden bearings and steel on steel contact points are lubricated and, if worn, replaced.
That any broken or worn parts or supports are promptly re-fastened or replaced.
The area around the well is being kept free of animal and human waste and garbage and that people are not doing dishes beside the well or mixing or using petrol (fuel), pesticides, or other pollutants near the well.
Make sure that nearby unused wells are propertly abandoned are are not filled with garbage or organic matter.
Test the well once a year for coliform, bacteria, nitrates and any other constituents of concern.
Disinfect drinking water wells at least once per year with bleach or hypochlorite granules.
Keep accurate records of all maintenance work & chlorination

These ongoing monitoring activities must be performed by villagers and appropriate actions initiated to correct any detected potential problems before the pump breaks down or the water becomes contaminated. About 10 percent of the cost of the pump must be raised every year and local people trained to make/get and install spare parts to ensure a wells continued functioning (UN, 1981). No project should be implemented if an organizational set-up of financial resources and committed people are not available for operating and maintaining the completed wells.

Foot Valve: Positive displacement pumps have a foot valve on the bottom of the cylinder. The purpose of the valve is to hold the column of water in the rising main while the piston is being pushed down after each upstroke. If you have to pump very fast for a long time before water comes out of the spout, the foot valve is likely not working correctly.

You can be fairly certain that there is problems with the foot valve if water comes out of the pump spout at a good rate when the pump handle is pumped very rapidly. The condition of the foot valve can be checked by pumping water from the well and then waiting 10-20 minutes. Then open the pump and check the position of the water column within the rising main. If it is high above the water level in the well and is near the pump spout, the foot valve is OK and the problem is more likely to be worn cup leathers (See Appendix L).

Open Top Cylinder: Foot valves are found in two basic cylinder configurations: "closed top" and "open-top" cylinders. Down-hole cylinders are usually larger diameter than the rising main and they contain the foot valve and the piston. When the piston needs servicing, the rising main must be removed along with the pump rod and the cylinder.
Open top cylinders are the same diameter as the rising main. This makes cup leather replacement much easier and quicker and reduces the potential for accidents since the rising main (often called "drop pipe" after hard learned lessons!) and cylinder are left in-place when the piston and pump rod are pulled-out.

Open top cylinders are, therefore, very beneficial in deeper wells where there are many lengths of rising main pipe. However, special tools are often needed to extract the foot valve and build-up of fine sand can jamb it in place over time. This can be a real problem because the lengths of rising main pipe are usually glue jointed rather than screwed together when working barrel cylinders are used.

Before you begin taking apart a pump that is not producing water, make sure that:

You have ownership permission to work on the well. This is really important since it is possible that you could drop things in the well or break parts of the pump while working on it. You could also be held responsible for future maintenance or bacterial problems. Finally, you could be perceived to be trying to steal the pump or to claim credit for the borehole; issues of organizational integrity and reputation will last long after you have gone!

Make sure there is water in the well. Use an electric water level tape or a stone on a rope to confirm that there is enough water in the well for the pump to work. If there is no water, assume that the pump is fine and don't take the time, energy and risks associated with taking it apart.

You understand how the pump works and that you have needed tools and parts. This is important because you will raise people's hopes as soon as you start working on a broken pump.

Handpump Repair Manuals

References

United Nations (1981) "Rural Water Supply", United Nations Department of Technical Cooperation for Development, Report of a United Nations Interregional Seminar, Uppsala, Swede, 6-17 October, 1980.

Wells: What to Do After the Flood

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