The more common chemical abatement technique is amendment with lime. Maybe fish bones are cheaper in some coastal locations, I don't know, but it's interesting

The more common chemical abatement technique is amendment with lime. Maybe fish bones are cheaper in some coastal locations, I don't know, but it's interesting. There's also some evidence that calcium supplements given concurrently with lead exposure could reduce the absorption into sensitive tissues (particularly brain and bones), but I don't know how strong the evidence is. EDIT: The depth of excavation is determined based on the expected use of the land, and how deep the contamination extends based on soil sampling. Anecdotally, I know that excavation of residential areas at the smelter superfund site in Pueblo (south of me) extended to two feet around the houses.