— corrosion is a problem, especially where the groundwater is aggressive, and it can affect the pump rods if they are not made of stainless steel, the rising main (if not galvanized iron tubing), the cylinder, the housing for the pumphead bearing, and other pumpstand parts;<br>
— handles become shaky or broken, mainly because of worn-out bearings;<br>
— the number of problems usually increases with increasing depth of the groundwater (the maximum lift for a pump varies according to the brand, but is usually 45–100 m).<br>— with some pump brands, or when the water must be lifted from a great depth, the pump handle may require considerable strength to turn it;<br>— to reduce the number of major repairs, the rising main should be made of the highest-quality material available;<br>— rigorous quality control is needed for deep-well piston handpumps, since many are produced in developing countries;<br>— deep-well piston handpumps may require considerable torque to start them, and the pump may be driven by a windmill; as a result, rotary pumps are often preferred because of their lower starting torque. ==Costs==In 1985, for a well 25–35 m deep, prices ranged from about US$ 40 for a cylinder, plunger and foot valve set (installed under a locally-made pumphead), to over US$ 2300 for a complete pump with stainless steel parts. Most good pumps cost US$ 300–500. ==Acknowledgements==* Brikke, François, and Bredero, Maarten. ''[http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC0QFjAB&url=http%3A%2F%2Fwww.who.int%2Fwater_sanitation_health%2Fhygiene%2Fom%2Flinkingintro.pdf&ei=cwJpT-zaO-OiiQKCst2rBw&usg=AFQjCNEWOQhTgF3a7lzhuw5OA2KmbVGxcA&sig2=Rt2EURUyGVqDcwFg6p0xAw Linking technology choice with operation and maintenance in the context of community water supply and sanitation: A reference document for planners and project staff]''. World Health Organization and IRC Water and Sanitation Centre. Geneva, Switzerland 2003.
