Prevention of N Fowleri infection.I

I thank all the Doctors for your precious advice regarding our queries. I understand that as advised by a previous specialist Doctor that N Fowleri is usually present in unclean or stagnant river or pond water and is rare in India. I read there were 15 or 16 cases found in India. I don't swim but I have a groundwater via jet pump/submersible connection in which water is stored in syntax tank. We can't get it cleaned for months or put Chlorine as it is kept on terrace. But the water from it, we have been using daily for almost 9 years now. Can such water in India have such amoeba present in it? Today I was washing face when I suddenly started sneezing and air got sucked up my nose as in while breathing in between sneezes. Can a drop of water be sucked into the sinuses and cause infection in this way or the water is safe and I shouldn't worry unless I head bath or swim in river or pond with stagnant water?