Prior to the construction of the Superstack, the waste gases contributed to severe local ecological damage. The Copper Cliff smelter was already home to some of the worlds tallest stacks, including two 500-foot chimneys constructed in 1928-29 and 1936. However these proved to be insufficient and compounded by open coke beds in the early to mid-20th century and logging for fuel, an inevitable near-total loss of native vegetation occurred. Of particular interest to geologists are the now exposed rocky outcrops, which have been permanently stained charcoal black, first by the pollution wafting over the decades from the roasting yards, then by the acid rain in a layer which penetrates up to three inches into the once pink-grey granite.