Final answer:
A potentially responsible party for contamination at a hazardous waste site includes the waste generator, the transporter who selected the site, and the landowner. The transporter who did not select the disposal site is typically not held liable.
Step-by-step explanation:
A potentially responsible party includes a variety of individuals or entities that could be held liable for contamination at a hazardous waste site. These parties generally include the generator of the waste, the transporter of the waste who selected the disposal site, and the current owner of the land where the waste is disposed. However, the transporter of the waste who did not select the disposal site is typically not included as a potentially responsible party. This is because their role is limited to the transportation of the waste without involvement in the decision-making process regarding where the waste is ultimately disposed of.