(a) As used in this Code section, the term "combined sewer overflow" or "CSO" means a sewage system so designed or constructed as to allow surface-water runoff to enter the conduit carrying sewage, industrial waste, or other waste and, when such conduit exceeds its maximum capacity, allows a discharge which bypasses the normal treatment works integral to such sewage system and allows untreated or incompletely treated sewage, industrial waste, or other waste to flow, directly or indirectly, into the waters of the state.

(b) After March 31, 1992, no person shall operate a CSO in this state unless he has obtained a permit to do so from the director. The director, under the conditions he prescribes, shall require the submission of such plans, specifications, and other information as he deems relevant in connection with the issuance of such permits. Compliance with permit limits shall be required for all CSO discharges under design conditions as determined by the director.

(c) The director is authorized to require as conditions in permits issued under this Code section the achievement of effluent limitations established pursuant to this article. In imposing effluent limitations as conditions in such permits, the director shall base his determination upon the assessment of technology and processes unrelated to the quality of receiving waters of this state. Effluent limitations required as conditions of such permits shall be achieved in the shortest reasonable period of time consistent with state law and the Federal Water Pollution Control Act, as amended. The director is further authorized to set schedules of compliance and include such schedules within the terms and conditions of such permits for the operation of a CSO and to prescribe terms and conditions for such permits to assure compliance with applicable effluent limitations and water quality criteria established pursuant to this article, including, but not limited to, requirements concerning recording, reporting, monitoring, and inspection to the extent permissible under this article and such other requirements as are consistent with the purposes of this article.

(d) Each permit issued pursuant to this Code section shall have a fixed term of five years and may be renewed by the director in accordance with such guidelines as he shall prescribe but only after the director has issued a written finding, based upon actual investigation, that the applicant has substantially followed any schedules of compliance established pursuant to subsection (c) of this Code section.