Water splashes from a public bathroom

In my office washroom, the janitors keep the floor dry using a mop. Now the toilets are separate from the area where there are wash basins. However, the janitors use the same mop to clean the floor of the entire washroom (toilet and the washbasin area). Now when washing myself or performing wudoo at the wash basins, drops of water usually fall down on the floor. Does these drops become napaak after splashing from the floor? In the start I tried to avoid these drops from falling and then bouncing on my feet and clothes, but it is almost impossible and every now and then I get water splashed on my feet and clothes. What I should do in such a case? If I become napaak, how can I perform salah then because I have no way to change my clothes in the office and it happens too frequently?