Final answer:
The exact number of fully cleaned up Superfund sites by 2016 is not specified in the provided references. Cleanup methods typically include soil removal, groundwater treatment, and site covering. The Love Canal cleanup is a prominent example, and ongoing issues like Cr(VI) contamination highlight the persistent challenges.
Step-by-step explanation:
The Superfund program, initiated to manage the cleanup of hazardous waste sites, has made significant strides in remediating areas that pose serious threats to both the environment and human health. By 2016, the program had analyzed numerous sites, but the exact number of Superfund sites fully cleaned up by that year is not provided in the reference information available. Cleanup methods commonly involve the removal of contaminated soil, the installation of drainage systems to treat contaminated groundwater, and the securing of the sites with layers of clay and plastic.
One of the most notable cleanups was the Love Canal incident, which prompted the establishment of the Superfund. This particular case resulted in Occidental Chemical paying a substantial sum for the cleanup efforts necessitated by hazardous waste contamination. Despite these efforts, problems with pollutants like Cr(VI) in groundwater persist in some locations, indicating that the challenge of managing hazardous waste is ongoing.