depth of us slag problems

http://www.citizen-times.com/article/DN/20101230/NEWS01/107170001

A state proposal to let two Middle Tennessee aluminum waste processing companies build a landfill in the city limits of a small community has unleashed public complaints and highlighted the dilemma of the need to recycle more versus the noxious byproducts left by recycling itself.

Two companies in Mount Pleasant 50 miles southwest of Nashville want to bury salty, aluminum-tainted leftovers that many landfill owners won't accept because of the smelly, potentially flammable ammonia that billows when the material gets wet.

etc etc

also

see, this one is very extensive

http://www.tennessean.com/assets/pdf/DN176927717.PDF