Treadle pump

The treadle pump is used in Bangladesh. Photo: Netherlands Water Partnership.

A simple, bamboo treadle pump can be constructed. Photo: International Development Enterprises.

The Malawi treadle pump is a high capacity treadle pump designed to lift water from shallow wells & surface sources. Photo: S.K. Industries.

The treadle pump is a foot-powered water pump widely used in Asia and spreading in Africa. It consists of two metal cylinders with pistons that are operated by a natural walking motion on two treadles.

There are several variations of the treadle pump:

The River Pump: is mounted on a portable metal stand so that it can be easily moved from one water source to another. It is used to pump from surface water sources. It requires an inlet hose for suction. A borehole is not required.
The Metal Treadle Pump: incorporates permanently attached metal treadles, which increases portability. It can be mounted on a borehole (like the basic Treadle Pump) to draw from groundwater sources. It can be mounted on a metal frame (like the River Pump) to draw from surface water sources.
The Concrete Pump: has PVC cylinders embedded in a concrete body. This prevents corrosion of the device in regions with saline groundwater. It is mounted on a borehole to draw from groundwater.
Plastic Pump: Using only plastic in the construction prevents corrosion in regions with saline groundwater. It can also be mounted on a borehole to draw from groundwater.

In the 1980s, International Development Enterprise (IDE) initiated a campaign to market the pumps to smallholder farmers. Over the course of 12 years, 1.5 million treadle pumps were purchased by farmers, increasing the farmers income by $150 million annually. The cost of the treadle pump scheme was $12 million, compared with conventional dam and canal systems, which would have cost $1.5 billion to irrigate a similar area. The treadle pump programme in India won an Ashden Award in 2006.

The treadle pump is also being promoted in Africa where it is installed by organizations such as Kickstart (former Approtec), who brand the treadle pump under the name MoneyMaker, and Enterprise Works. Models of the treadle pump such as the MoneyMaker and the Soka-pump are now widely used for small-scale "spray" irrigation.

Currently, over 2 million treadle pumps have been installed worldwide. Up to 1.3 million treadle pumps are in use Asia, and some 35,000 in Eastern Africa. They are being produced in 300 local workshops worldwide and used by more than one million poor rural families that otherwise could not have afforded an irrigation pump.

Suitable conditions

The treadle pump can be used on small farms which draw irrigation water from 1-7 m deep. A treadle pump can pump around 100 litres / min from 4 meters depth.

Because a treadle pump is a suction pump, the depth from which water can be drawn is limited to 7m.

Distribution: about 2,000,000 treadle pumps were sold in Bangladesh and about the same number in India.

Advantages	Disadvantages
- Simple and cheap - Ergonomic treadle motion / Less intensive operation (foot operated) - Produced in local workshops / Maintenance uses local skills and materials. - Usually leads to generation of US$100-500 additional income per year for rural households in Africa and Asia	- Pumping depth limited to 7m.

Construction, operations and maintenance

Treadle pump diagram. Click image to zoom.
Photo: Howtopedia.

Design

Cylinder diameter: 3.5 inch and 5 inch (90mm - 130mm)
Stroke: variable
Yield: (75 watt input, at 5 m head)~ 4.5 m³/hour
Population/Area served: 0.25 hectare
Type of well: collapsible tube well or dug well

Treadle pumps can be manufactured locally in simple metalworking shops. The treadles and support structure are made of locally available, inexpensive material, such as bamboo. All components (or junction box) are made from mild steel; Piston-mild steel with plastic seal (cup Seal); foot valve-leather flap; rising main-PVC pipe or bamboo; various types of screens are used.

The installation of the Treadle pump is easy and does not need any lifting equipment or special tools. The drillers who sink the tube well with the sludger method also install the pump.

Two pedals are connected to the two pistons. The pump is powered by shifting the weight from one pedal to the other, lifting the pistons. Water is supplied through a hose which draws water from a borehole or surface water.

All household members are able to operate the pump, allowing farmers to make efficient use of family labour.

Maintenance

If designed correctly, treadle pumps can be easily maintained with standard replacement parts available in local markets at a low cost. All repairs can be done without the use of tools.

Costs

The treadle pump is very cost-effective. Its low cost makes it accessible to even very poor farmers who can use it to grow dry-season vegetables for home consumption and for sale. In Bangladesh, a pump costs US$ 20. On average, farmers are able to generate more than US$100 per year in extra income. Income from treadle pumps adds US$100 million to the GNP of Bangladesh annually. Production and sales are sustainable now without external aid. With this technology, many families have increased their income. Some farmers who started with this pedal pump have now bought a motorized pump.

A treadle pump costs US$ 20 in Bangladesh, and US$ 50-80 in Africa.
Approx US$ 100-200 including tube well (depending on installation depth and drilling method)
The cost of introduction lies around US$ 20,000 per project, including training, engineering and first production.