Evaluate the advantages and disadvantages of ultraviolet treatment compared to chlorination, based on your evaluation which method would you recommend ............
.........for a small town wishing to construct new water treatment facilities and why?
One of the reasons that one might lean more heavily towards chlorination as the preferred method would be the fact that it is so widely practiced and is a practice that many municipalities are familiar with. So the equipment and supplies and testing methods are widely available, less expensive, and more well tested than UV treatment which is relatively new. This might be particularly important when it comes to a small municipality that is likely not ready to spend more money than is absolutely necessary.
Given the testing that has taken place in Switzerland, and particularly if those results can be repeated, it might be difficult to turn away from solar disinfection as a variable of UV disinfection that would be very inexpensive and for which the equipment is not expensive.
But if the two choices are simply UV and chlorination, I would likely have to make the choice based on what is available and inexpensive and at this point that means chlorination.