Wikipedia has a little info on the pollution from the zinc factory [0]. There's a PDF describing the government's remediation work [1], which finished in 1995.

Wikipedia has a little info on the pollution from the zinc factory [0]. There's a PDF describing the government's remediation work [1], which finished in 1995. The pollution killed all microbial life, so the trees and dead vegetation could not decay and just lay on the ground for decades. There's a creepy photo in the PDF. EPA developed a soil treatment and tested two ratios of ingredients. One ratio was good for grass and the other worked for trees. Finally, they used the average of the two ratios. They hoped that it would allow grasses to grow quickly and prevent rain from washing away the treatment and still allow trees to grow later. I'm curious if trees were finally able to grow. I think the answer is no, since there were few trees after fifteen years, when you visited in 2010. Perhaps the ratio was good, but some areas (like the ridge) lost too much of the treatment material by erosion before grasses could grow and stabilize the soil? EPA could follow up and order a re-application of the treatment in the affected areas. [0] https://en.wikipedia.org/wiki/Lehigh_Gap#Lehigh_Gap_Nature_Center https://en.wikipedia.org/wiki/Lehigh_Gap#Lehigh_Gap_Nature_C... [1] https://web.archive.org/web/20070929101630/http://www.biosolids.org/docs/source/CarbonPA.pdf https://web.archive.org/web/20070929101630/http://www.biosol...