For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
   CLEANUP. The removal of the hazardous substances to a place where the waste will not cause any danger to persons or the environment, in accordance with state statutes, rules and regulations therefor or the treatment of the material as defined herein to eliminate the hazardous condition, including the restoration of the area to a general good appearance without noticeable odor as far as practicable. CLEANUP includes all actions necessary to contain, collect, identify, analyze, treat, disperse, remove or dispose of a hazardous substance and to restore the site from which the hazardous substance was cleaned up.
   HAZARDOUS CONDITION. Any situation involving the actual, imminent or probable spillage, leakage or release of a hazardous substance onto the land, into a water of the city or into the atmosphere which creates an immediate or potential danger to the public health or safety or to the environment.
(Iowa Code § 455B.381(4))
   HAZARDOUS SUBSTANCE. Any substance or mixture of substances that presents a danger to the public health or safety and includes, but is not limited to, a substance that is toxic, corrosive or flammable, or that is an irritant or that generates pressure through decomposition, heat or other means. HAZARDOUS SUBSTANCE may include any hazardous waste.
   HAZARDOUS WASTE. A waste or combination of wastes that, because of its quantity, concentration, biological degradation, leaching from precipitation, or physical, chemical or infectious characteristics, has either of the following effects:
      (1)   Causes or significantly contributes to an increase in mortality or an increase in serious irreversible or incapacitating reversible illness; or
      (2)   Poses a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported or disposed of, or otherwise improperly managed.
   RESPONSIBLE PERSON. The person, whether the owner, agent, lessor or tenant, in charge of the hazardous substance being stored, processed or handled, or the owner or bailee transporting hazardous waste or substances, whether on public ways or grounds or on private property, where the spill would cause danger to the public or to any person or to the environment.
(1999 Code, § 36.01)