A number of Penn National Gaming subsidiaries that operate casinos learned from industry sources that some of the gaming chips they had been using may have contained high levels of lead. After determining that the casinos may have disposed of the gaming chips that contained high levels of lead (which may have been a RCRA characteristic waste when disposed), the csinos undertook a voluntary self-evaluation and disclosed to EPA under the audit policy several instances where Penn National gaming may not have complied with the RCRA requirements for hazardous waste generations and disposal.