For F. Scott Fitzgerald's "The Great Gatsby," places represent various aspects of the 1920s society that the author depicts. For instance, the East Egg represents the aristocratic rich of old, established names while the West Egg represents the nouveau riche of the era. And, the Valley of Ashes represents the moral and social decay of America and New York City the amoral quest for money and pleasure.
The Valley of Ashes consists of a long stretch of barren land that has been used for the dumping of industrial ashes. As such, it represents the moral and social decay, the unchecked pursuit by the rich for wealth and their own pleasure without regard for the destruction that they cause. It is, then, appropriate that Myrtle Wilson, who falls victim to the callous, wealthy Tom Buchanan and his wife Daisy, should live there along with her enervated husband George Wilson, a man who loses all his vitality.
Just as the Valley of Ashes symbolizes the corruption of the era, so does Gatsby's having changed his name from Gatz indicate the deceit and corruption in his person as he pursues the American Dream as one of possessing money and having limitless pleasure. With these false values, Gatsby longs to create a past that has vanished, but is incapable of doing so. When his dream of a life with Daisy dies, the Owl Eyes of the Valley of Ashes seem to see everything as Gatsby himself dies, and himself returns to ashes.
Jay Gatsby's real name was James "Jimmy" Gatz. He was from North Dakota and was born poor. He changes his name when he was quite young (a teenager) because he wants to make a new persona for himself.
The valley of the ashes is a really gloomy place that seems to be inhabited by a town full of people. I would think that the answer you are looking for is that Tom Buchanan's mistress and her husband live there. Her name is Myrtle Wilson and her husband's name is George. He runs a garage down in the valley of the ashes.