1. a) Prior to conducting site investigation activities pursuant to Section 734.315, 734.320, or 734.325 of this Part, the owner or operator must submit to the Agency for review a site investigation plan. The plan must be designed to satisfy the minimum requirements set forth in the applicable Section and to collect the information required to be reported in the site investigation plan for the next stage of the site investigation, or in the site investigation completion report, whichever is applicable.
2. b) Any owner or operator intending to seek payment from the Fund must, prior to conducting any site investigation activities, submit to the Agency a site investigation budget with the corresponding site investigation plan. The budget must include, but not be limited to, a copy of the eligibility and deductibility determination of the OSFM and an estimate of all costs associated with the development, implementation, and completion of the site investigation plan, excluding handling charges and costs associated with monitoring well abandonment. Costs associated with monitoring well abandonment must be included in the corrective action budget. Site investigation budgets should be consistent with the eligible and ineligible costs listed at Sections 734.625 and 734.630 of this Part and the maximum payment amounts set forth in Subpart H of this Part. A budget for a Stage 1 site investigation must consist of a certification signed by the owner or operator, and by a Licensed Professional Engineer or Licensed Professional Geologist, that the costs of the Stage 1 site investigation will not exceed the amounts set forth in Subpart H of this Part.
3. c) Upon the Agency's approval of a site investigation plan, or as otherwise directed by the Agency, the owner or operator shall conduct a site investigation in accordance with the plan [415 ILCS 5/57.7(a)(4)].

4. d) If, following the approval of any site investigation plan or associated budget, an owner or operator determines that a revised plan or budget is necessary in order to determine, within the area addressed in the applicable stage of the investigation, the nature, concentration, direction of movement, rate of movement, and extent of the contamination, or the significant physical features of the site and surrounding area that may affect contaminant transport and risk to human health and safety and the environment, the owner or operator must submit, as applicable, an amended site investigation plan or associated budget to the Agency for review. The Agency must review and approve, reject, or require modification of the amended plan or budget in accordance with Subpart E of this Part.

   BOARD NOTE: Owners and operators are advised that the total payment from the Fund for all site investigation plans and associated budgets submitted by an owner or operator must not exceed the amounts set forth in Subpart H of this Part.

5. e) Notwithstanding any requirement under this Part for the submission of a site investigation plan or budget, an owner or operator may proceed to conduct site investigation activities in accordance with this Subpart C prior to the submittal or approval of an otherwise required site investigation plan or budget. However, any such plan or budget must be submitted to the Agency for review and approval, rejection, or modification in accordance with the procedures contained in Subpart E of this Part prior to receiving payment for any related costs or the issuance of a No Further Remediation Letter.

   BOARD NOTE: Owners or operators proceeding under subsection (e) of this Section are advised that they may not be entitled to full payment. Furthermore, applications for payment must be submitted no later than one year after the date the Agency issues a No Further Remediation Letter. See Subpart F of this Part.

The investigation of the release must proceed in three stages as set forth in this Part. If, after the completion of any stage, the extent of the soil and groundwater contamination exceeding the most stringent Tier 1 remediation objectives of 35 Ill. Adm. Code 742 for the applicable indicator contaminants as a result of the release has been defined, the owner or operator must cease investigation and proceed with the submission of a site investigation completion report in accordance with Section 734.330 of this Part.