I believe the answer is: <span>reaction formation
</span>reaction formation refers to a situation when a person give an exact opposite response to his/her own <span>own disturbing or socially unacceptable thoughts or emotions. Reaction formation acted as a defense mechanism to repel the anxiety that come by negative perception of ourself.</span>
It could be because the water is in constant motion, in someway filtering it with help from the sun heating the water, killing the bacteria.