Unless directed to do otherwise by the Department, an owner and an operator of a storage tank system and a responsible party shall perform each of the following abatement measures: Remove as much of the regulated substance from the storage tank system as is necessary to prevent further spilling, releasing, or discharging of the regulated substance to the environment; Visually inspect any aboveground spills, releases, or discharges or exposed belowground spills, releases, or discharges and prevent further migration of the spilled, released, or discharged regulated substance into surrounding soils, surface water, and groundwater; Continue to monitor and mitigate any fire and safety hazards posed by vapors or free product that have migrated from a UST excavation zone or a storage tank system site and entered into subsurface structures, such as sewers or basements; Remedy hazards posed by contaminated soils that are excavated or exposed as a result of a spill, release, or discharge confirmation, site investigation, abatement, or corrective action activity by: Removing contaminated soils from the site within 50 days of excavation for treatment or disposal in compliance with applicable federal, State, and local laws; or Treating contaminated soils in accordance with a corrective action plan approved by the Department; Unless the location, extent, and source of a spill, release, or discharge were confirmed during a site check conducted in accordance with COMAR 26.10.08.03C or a closure site assessment conducted in accordance with COMAR 26.10.10.03A, perform a site check to determine the location and extent of a spill, release, or discharge by: Measuring for the presence of the spill, release, or discharge in the area where contamination is most likely to be present; and Selecting sample types, sample locations, and measurement methods for identifying the presence and source of the spill, release, or discharge that consider the: Nature of the stored substance; Site soil characteristics; Type of backfill; Depth to groundwater; and Other relevant factors for identifying the presence and source of the spill, release, or discharge; and Investigate to determine the possible presence of free product and begin free product removal as soon as practicable in accordance with Regulation .05 of this chapter. Within 20 days of confirming a spill, release, or discharge, or within another reasonable time period required by the Department, an owner and an operator of a storage tank system and a responsible party shall submit a report to the Department summarizing the initial abatement steps taken in compliance with §A of this regulation and any resulting information or data.