The Department may approve the use of a registered environmental consultant to provide oversight for the assessment and remediation of a site under this Part based on the risk posed by the site and the availability of Department staff for oversight of remediation activities. If remediation under this Part is not undertaken voluntarily, the Department may not require the use of a registered environmental consultant to provide oversight for the assessment and remediation of a site under this Part. (2011-186, s. 2; 2015-286, s. 4.7(a).)