716B.4  Unlawful storage or treatment of hazardous waste — penalties.
  A person who knowingly or with reason to know, treats or stores hazardous waste without a permit issued pursuant to 42 U.S.C. §  6925 or §  6926 is guilty of an aggravated misdemeanor and upon conviction shall be punished by a fine of not more than twenty-five thousand dollars for each day of violation or imprisonment for not more than two years, or both. If the conviction is for a violation committed after a first conviction under this section, the person is guilty of a class “D” felony and shall be punished by a fine of not more than fifty thousand dollars for each day of violation or imprisonment for not more than five years, or both.
88 Acts, ch 1080, §6