There is really only one that ...

There is really only one that is both effective and easy to apply. That is chlorine. This can be as gas or hypochlorite addition. It does require effective pre-treatment to make the water suitable for disinfection depending on the raw water. Also a useful oxidant to remove iron and manganese. Needs a contact time with a free chlorine residual at the end, which may then be converted to chloramine to last longer in distribution. Very widely used. The only exception in pathogens would be oocysts such as Giardia and Cryptosporidium for which the effective treatment would be UV to render non infective or membrane filtration to remove.