our basement has a bad smell. it is coming from a drain pipe in a room in the basement that appears to be made of iron. I am uncertain where the drain goes. we have had our septic tank inspected which was ok. we have well water, and occasionally the water has a bad smell. I am uncertain if the two are related. what would be the next course of action to investigate and eleimate the smell? does irrigating the pipe out with water do anything? are these two related.