Zombie apocalypse bonus activity

manhattan is ground zero for an invasion of the living dead. the origin of the first case remains unknown, but the number of flesh-eating zombies is growing exponentially*. food abounds in the densely-populated gotham city, and it is now common to see people being eaten alive on the street. the only known method for killing the zombies permanently is a gunshot wound to the head, or some other method that destroys their brains. this approach is proving ineffectual. their numbers are growing unchecked and panic has gripped the city. even trained military sharpshooters are unable to eliminate the ghouls fast enough to outpace their emergence. you make a key observation when you see a group of zombies crowded around a leaky fire hydrant, eagerly lapping up water. you surmise that their high-protein diet generates a lot of nitrogenous waste products. in addition to a nervous system for controlling locomotion, you realize that the living dead must have a way to eliminate nitrogenous wastes. anecdotal reports have surfaced that zombies have kidney-like structures, but you know that shooting their kidneys with bullets will be even more ineffectual than shooting their brains; another approach is necessary. your objective is to develop a method for permanently killing zombies that targets their ability to eliminate nitrogenous wastes. you must also address the potential impact your method will have on the normal human population.