(a) As used in this Code section, the term:

(1) "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 this state.

(2) "Sewage overflow" means that untreated sewage, industrial waste, or other waste which is discharged when a CSO exceeds its maximum capacity so that such material bypasses the normal treatment works integral to such sewage system and flows untreated or incompletely treated into the waters of this state.

(b) Any person who owns or operates a CSO in this state on July 1, 1990, shall devise and submit to the director for approval a detailed plan to eliminate sewage overflow or to treat or control sewage overflow so that discharges flowing from such CSO shall not cause a violation of water quality standards in the receiving stream or permit limits for publicly owned waste-water treatment facilities with combined sewer overflows established by the division or by the federal Environmental Protection Agency under the provisions of the Federal Water Pollution Control Act amendments of 1972, 33 U.S.C. Section 1251 and following, as amended by the Clean Water Act of 1977 (P.L. 95-217). Compliance with such standards and permit limits shall be required for all CSO discharges under design conditions, including without limitation storm event frequency, intensity, and duration and treatment technology, as determined by the director based on a site-specific determination of water quality impacts resulting from said discharges.

(c) (1) The plan required by subsection (b) of this Code section shall include, as a minimum, provision for realistic implementation of means to eliminate sewage overflow or effectuate treatment of overflow to meet or exceed such water quality standards in accordance with the following schedules:

(A) Any person who submitted a plan pursuant to subsection (b) of this Code section prior to August 1, 1990, shall implement such plan so that construction is substantially complete and operational to meet the water quality standards in the receiving stream or permit limits as defined by the director not later than December 31, 1993; and

(B) Any person who did not submit a plan pursuant to subsection (b) of this Code section prior to August 1, 1990, shall comply with the following schedule:

(i) The director shall define the design conditions of subsection (b) of this Code section by December 31, 1991, using information provided by CSO owners and information collected by the director;

(ii) The CSO owners shall prepare approvable plans and specifications by October 1, 1992, and, based on the director's approval of plans and specifications by December 31, 1992, the owners shall commence construction of the approved CSO facilities by April 1, 1993; and

(iii) The construction shall be substantially complete and operational to meet the water quality standards in the receiving stream or permit limits as defined by the director by December 31, 1995.

(2) The owner of any combined sewer overflow system which discharges into the Chattahoochee River or its tributaries who failed to implement an approved plan by December 31, 1995, shall, in lieu of the liability and penalties provided in Code Sections 12-5-51 through 12-5-53, pay a civil penalty in the amount of $10,000.00 per day until the construction is completed but not later than October 1, 1997, after which date the penalty shall be increased to $100,000.00 per day until construction is completed; provided, however, that if such person owns or operates two separate combined sewer overflow systems, he or she shall pay a separate penalty on the second such system in the amount of $10,000.00 per day until construction is completed, but not later than July 1, 1998, after which date the penalty shall be increased to $100,000.00 per day for such system. On and after the dates the penalties for each such system increase to $100,000.00 per day, the owner or operator shall be subject to the liabilities and penalties provided in Code Sections 12-5-51 through 12-5-53 with regard to the respective system.

(3) In addition to the penalties provided in paragraph (2) of this subsection, the owner or operator of a combined sewer overflow system shall not permit any additional sewer connections to such system until construction has been completed.