▁the ▁entire ▁system . ▁ ▁The ▁water way ▁is ▁heavily ▁used ▁by ▁b arg es ▁transport ing ▁bulk ▁goods ▁such ▁as ▁gra in ▁and ▁oil . ▁It ▁is ▁used ▁in ▁the ▁summer ▁and ▁early ▁fall ▁by ▁tour ists ▁in ▁pleasure ▁boats ▁cru ising ▁the ▁Great ▁Loop . ▁The ▁Illinois ▁River ▁is ▁an ▁important ▁part ▁of ▁the ▁Great ▁Loop , ▁the ▁circ umn avigation ▁of ▁Eastern ▁North ▁America ▁by ▁water . ▁ ▁The ▁City ▁of ▁Pe oria ▁is ▁developing ▁a ▁long - term ▁plan ▁to ▁reduce ▁combined ▁se wer ▁overflow s ▁to ▁the ▁Illinois ▁River , ▁as ▁required ▁by ▁the ▁U . S . ▁Environment al ▁Prote ction ▁Agency ▁and ▁the ▁Illinois ▁Environment al ▁Prote ction ▁Agency . ▁During ▁dry ▁weather , ▁se w age ▁flows ▁safely ▁through ▁the ▁city ' s ▁se wers ▁to ▁the ▁Gre ater ▁Pe oria ▁San itation ▁District ▁waste water ▁treatment ▁plant . ▁However , ▁about ▁ 2 8 ▁times ▁a ▁year , ▁mel ting ▁snow ▁or ▁rain water ▁can ▁over wh elm ▁the ▁se wers , ▁causing ▁un tre ated ▁se w age ▁to ▁overflow ▁into ▁the ▁Illinois ▁River . ▁Pe oria ▁was ▁required ▁to ▁examine ▁the ▁se wer ▁overflow s ▁and ▁prepare ▁a ▁long - term ▁control ▁plan ▁to ▁meet ▁C lean ▁Water ▁Act ▁requirements ▁and ▁protect ▁the ▁Illinois ▁River . ▁The ▁city ▁had ▁to ▁submit ▁its ▁plan ▁by ▁December ▁ 2 0 0 8 ▁to ▁U . S . ▁E PA ▁and ▁Illinois ▁E PA . ▁ ▁The ▁issue ▁was ▁still ▁under ▁discussion ▁as ▁recently ▁as