IN.gov - Skip Navigation

Note: This message is displayed if (1) your browser is not standards-compliant or (2) you have you disabled CSS. Read our Policies for more information.


Subscribe for e-mail updates
Print This Page Rate This Page Suggest a Link E-mail This Page HELP Find a Person Find an Agency

IDEM > Environmental Cleanup > RISC: Risk Integrated System of Closure > RISC: Nondefault Closures RISC: Nondefault Closures

The following are examples of nondefault closures that have been approved by IDEM in the past. Please note that these nondefault closures were determined using site-specific information and may not be appropriate for other sites.

  • Performed a TPH fractionation analysis and calculated the closure levels based on site-specific TPH fractions, not the default TPH closure levels
  • Modified industrial exposure assumptions to more accurately characterize the conditions of the site
  • Demonstrated plume stability for groundwater closure using historical groundwater monitoring data
  • Collected fewer samples than the default recommendation based on site-specific characteristics
  • Substituted a smaller dilution attenuation factor for a site larger than ½ acre to determine closure levels
  • Substituted an analytically determined site-specific fraction of organic carbon (foc) value for the default value to determine the closure level for organic compounds using the soil-to-ground water partitioning model
  • Eliminated the migration to groundwater pathway from consideration for surface soil by demonstrating the contaminant of concern is not mobile
  • Eliminated the direct contact pathway by capping the contaminated surface soil to prevent contact and by regulating future excavation activity with an Environmental Restrictive Covenant (ERC)
  • Used an Environmental Restrictive Covenant (ERC) to restrict a property from being becoming residential property in the future
  • Built an engineering control, such as a slurry wall, to prevent contaminant from moving off-site and mandated the upkeep of the engineering control with an Environmental Restrictive Covenant (ERC)