This may be the only case ever that I was just as excited for Saturday morning as I was for Friday night. At 7am, the bus containing myself and my Environmental Case Studies class left for Palmerton, PA to visit the Lehigh Gap Nature Center and conjunctively the Palmerton Zinc Pile Superfund Site. Yes, you read the sentence right. A superfund site that coexists as a nature center. What!?
To give a brief history, this area was deemed a superfund site after waste from a zinc smelting company in Palmerton did some damage on the surrounding environment. The face of Blue Mountain went from being lively and vegetated to a deserted “moonscape” as they say, devoid of most living animals and plants. This was caused by acid rain and extremely elevated levels of zinc and other heavy metals deposited in the soil, all from the zinc smelting byproducts.
The Lehigh Gap Nature Center took on the challenge of remediating the side of Blue Mountain, and they’ve done a great job. They took the engineering approach of doing what nature would do; since warm season grasses successfully grow in metal-containing soil, they were planted and are thriving on the formerly disrupted side of Blue Mountain. Hopefully this will lead to the next step in forest succession.
Ironically, a major inhibitor of this remediation project is caused by phytoremediation. Birch trees are growing here and translocating the heavy metals from the soil into their biomass. Once the leaves fall, the heavy metals in the leaves are again becoming available to the surrounding ecosystem. This ultimately undoes what the nature center strives to do: gradually bury the contaminated soil with layers of the warm-season grasses.
This is what a birch tree leaf with elevated metal levels looks like:
The zinc essentially prevents the chlorophyll from working, so unlike a normal leaf where it changes color from one side to the other, you can tell this leaf is contaminated because it is dying at the border and moving its way towards the center.
Now next time you’re on a superfund site, you’ll know which leaves not to…eat. If only somebody could warn the animals to do the same thing!