Some public handwashing facilities do pose a small risk of re-contamination. However, the absence of them would create a much greater concern for transmission. Hand re-contamination is possible because at the end of handwashing, when your hands are clean, the tap has to be turned off - but this tap may be dirty from when you initially touched it. There have been some great examples of no-touch handwashing facilities to mitigate this issue. Most of these use foot pedals to control the water and soap. Others have created touch-free adjustments for standard handwashing facilities. A more simple and well known touch-free handwashing device is the tippy tap. Instructions on tippy tap construction have been made available in a range of languages here.
Even if you are using bucket-style handwashing facilities, these normally come with an on/off lever to dispense water. The good thing about this (as opposed to a tap that turns on and off) is that it can be pushed with an elbow to switch it off, thus mitigating the contamination risk. Watch this video to see an example.
In several countries, we are also seeing that individuals are setting up handwashing stations near markets as small money earners or that organisations are paying ‘hygiene monitors’ to ensure that soap and water are always available at the public facilities they construct. In these situations, the person monitoring the station can switch the tap on and off for each person so that it is effectively touch-free. If your organisation is planning on paying people to monitor handwashing facilities, please do consider the sustainability of this approach or how you will phase this out. In addition, you may wish to promote regular cleaning of taps on public facilities.