I live in the PNW and to make a long story short, we had some standing water in our crawlspace. So we had a plumber install a sump pump and lay down new plastic vapor barrier. But, ever since they came out, a musty/earthy smell is coming from the crawlspace. I can't figure out what it is...there's no mold or anything down there, and it's not a sewage smell. The vents are open in the crawlspace and you can even smell it from outside the house. Any ideas on what it is or how to get rid of it? The plumber said to let things dry out but I think I'm not convinced.