The Natural Resources and Environmental Protection Act (NREPA) holds waste generators liable for releases that result from the waste materials they generate. In order to provide an incentive for companies to recycle secondary materials, Public Act 71 of 1995 amended the NREPA to exclude from liability for cleanup costs persons who arranged the sale or transport of a secondary material, provided that the material had been separated or removed from the solid waste stream for reuse or recycling, and substantial amounts of the material were consistently used in the manufacture of products that could otherwise be produced from a raw or virgin material. Public Act 71, however, did not specify that the recycling activities had to occur on or after June 5, 1995, when Public Act 71 took effect. Therefore, according to the Department of Environmental Quality (DEQ), some companies have applied the law retroactively to recycling activities that occurred before the exemption took effect. Since the exemption was designed to promote future recycling of secondary materials, according to the DEQ, it was suggested that the State should be able to recover response activity costs incurred before the effective date of the exemption.