Research into the viability of using earthworms to process hazardous material with an elevated heavy metal content at abandoned industrial sites [has / have] been conducted in South America. The researchers believe that the species Eisenia fetida, known as the common earthworm, has the potential to be wielded as an effective tool when dealing with hazardous solid and liquid with high metal content at these sites. In one segment of their study, compost that had been produced by these worms worked as an effective absorbent substrate for cleaning contaminated wastewater containing [high / highly] levels of nickel, chromium, and lead. In the other segment, the worms were applied directly to a variety of landfill soils for the remediation of arsenic and mercury — after two weeks, 42 to 72% of the arsenic and 7.5 to 30.2% of the mercury [had removed / had been removed]. Earthworms could represent an inexpensive and effective bio-remediation alternative to complex and costly traditional industrial cleanup methods.