What should you do when you have doubt about a food to become najis ? One of tap of my house got najis but due to not paying attention at that time i don't remember whether it got najis with najis ul ayan or with muttanajis , if it is due to muttanajis second touch then it will not transfer najasat from tap to my hand and from my hand to foodBut if it would be najis ul ayan than food will be 3rd touch which can make it najisBut due to forgetfulness I don't remember how did tap got najis What should I consider? My food as najis or not ?

The tap is connected to a source of Kurr water and this should have purified the tap upon contact as long as the impurity is not still present by color taste or smell