455H.203  Statewide standards.
  1.  Statewide standards shall be adopted by the commission after consideration of the joint recommendations of the department and the technical advisory committee. The standards must provide for the protection of the public health and safety and the environment.
  2.  In establishing these standards, all of the following shall be considered:
  a.  Separate standards shall be established for hazardous substances in soil, in groundwater which is a protected groundwater source, and in groundwater which is not a protected groundwater source.
  b.  In groundwater which is a protected groundwater source, the standards shall be the maximum contaminant levels established pursuant to the department’s drinking water standards or, for contaminants that do not have established drinking water standards, the standards shall be derived in a manner comparable to that used for establishment of drinking water standards. An affected area shall not be required to be cleaned up to concentration levels below or more restrictive than background levels.
  c.  In groundwater which is not a protected groundwater source, the standards shall be no more protective than a standard reflecting an increased cancer risk of one in ten thousand from exposure to contaminants that are known or probable human carcinogens; a standard reflecting a noncancer health risk of one-tenth from exposure to contaminants that are possible human carcinogens; or a standard reflecting a noncancer health risk of one from exposure to contaminants that are not known, probable, or possible human carcinogens. An affected area shall not be required to be cleaned up to levels below or more restrictive than background levels.
  d.  In soil, the standards shall be no more protective than a standard reflecting an increased cancer risk of five in one million from exposure to contaminants that are known or probable human carcinogens; a standard reflecting a noncancer health risk of one-tenth from exposure to contaminants that are possible human carcinogens; or a standard reflecting a noncancer health risk of one from exposure to contaminants that are not known, probable, or possible human carcinogens. An affected area shall not be required to be cleaned up to concentration levels below or more restrictive than background levels.
  e.  Statewide standards specified in paragraphs “b”, “c”, and “d” assume exposure to individual contaminants in groundwater or soil. If more than one contaminant exists in a medium or exposure to contaminants can occur from more than one medium, standards shall be adjusted to reflect a cumulative increased cancer risk that is no less protective than one in ten thousand and a cumulative noncancer health risk to the same target human organ that is no less protective than one. Risks associated with background levels of contaminants shall not be included in the cumulative risk determination.
  3.  The demonstration that the affected area meets the statewide standard shall be documented by the participant, as appropriate, in the following manner:
  a.  Compliance with cleanup levels shall be demonstrated by collection and analysis of representative samples from the environmental medium of concern.
  b.  A final report that documents compliance with the statewide standard shall be submitted to the department which includes, as appropriate, the descriptions of procedures and conclusions of the site investigation to characterize the nature, extent, direction, rate of movement at the site and cumulative effects, if any, volume, composition, and concentration of hazardous substances in environmental media, the basis for selecting environmental media of concern, documentation supporting the selection of residential or nonresidential exposure factors, descriptions of removal or treatment procedures performed in remediation, and summaries of sampling methodology and analytical results which demonstrate that hazardous substances have been removed or treated to applicable levels.
97 Acts, ch 127, §10; 2002 Acts, ch 1091, §1