Date of Award
Master of Science (MS)
Charles S. Melching
Clifford J. Crandall
Daniel H. Zitomer
Although most reaches of the Chicago Waterway System (CWS) meet the General Use Water Quality Standards a high percentage of the time, dissolved oxygen (DO) standards are not met in the CWS during some periods for both the WYs 2001 and 2003 as representative of wet and dry years. Several methods were used to solve this problem; however, they were inadequate for achieving the proposed DO standards. Therefore, a method of integrating the alternative DO remediation methods into one integrated strategy for improving water quality is considered in this study.
The main purpose of this study is the application of the DUFLOW model to improve DO concentrations in the CWS during the WYs 2001 and 2003. Two sets of DO standards needed to be achieved: 90 and 100% compliance with the IEPA's proposed DO standards, and the MWRDGC's proposed DO standards. In order to meet both standards, the following DO remediation methods were considered: 1) flow augmentation practices on the NSC, Bubbly Creek, and the Little Calumet River (north); 2) Side-stream Elevated Pool Aeration (SEPA) stations operational adjustments; and 3) the supplemental aeration stations on the CWS.
The results show that flow augmentation on the NSC and on Bubbly Creek can be combined to achieve 90% compliance with the IEPA's proposed DO standards for both years. However, the combination of flow augmentation, operational changes for the existing SEPA stations, and new aeration stations were required to meet 100% compliance with the IEPA's standards. For WYs 2001 and 2003, additional new aeration stations with the maximum DO loads of 80 or 100 g/s were needed along the CWS. For the MWRDGC's standards, a method of combing a 24 MGD transfer of aerated flow on the NSC with adjustment of the operating hours of the Devon Avenue in-stream aeration station and 2 new aeration stations on the SBCR can be an effective management, whereas only 24 MGD of aerated flow augmentation plus 1 new aeration station on the SBCR can meet the MWRDGC standards for WY 2003. A maximum oxygen load of 80 g/s is applied for three new aeration stations.