Budget Message / Highlights - Metropolitan Water Reclamation ...

METROPOLITAN WATER RECLAMATION DISTRICT OF GREATER CHICAGO
2009 BUDGET
the DO standards proposed in R08-9, and, if so, what the additional electricity requirements would be to meet the
new standards. The field work was completed in 2008 and a final report for the project will be issued in 2009.
• Dissolved Oxygen Modeling: Beginning in 2003, the District began working with Dr. Charles Melching of
Marquette University to develop a state of the art unsteady state hydraulic and water quality model (CAWs WQ
Model). This CAWs WQ Model was completed in 2005 and calibrated for several typical wet weather periods. It
has been a tool for all of the engineering studies the District has undertaken. The CAWs WQ Model is currently
undergoing refinement to improve the calibration, and extend its abilities to simulate a wider range of conditions. It
is being calibrated to simulate entire typical wet and dry water years. This improved CAWs WQ Model will
provide a better assessment of the attainability of proposed dissolved oxygen criteria under a range of expected
conditions. Existing available modeling analysis only examined selected conditions, and utilized a model that
needed important improvements. This modeling work is expected to be completed by early 2009.
• Flow Augmentation of the Upper North Shore Channel: In 2005, the District initiated a study, through its
consultant CTE/AECOM, to determine water quality management options for the Upper North Shore Channel
(UNSC). The UNSC is a four-mile segment of the CAWs that extends from Lake Michigan at the Wilmette
Pumping Station to the outfall of the North Side WRP and is plagued with low DO due to stagnant flow. Using the
CAWs WQ Model developed for the District by Marquette University, CTE/AECOM Engineers determined that
augmenting the flow in the UNSC with 100 million gallons per day of aerated North Side WRP effluent was
optimal, at a present worth cost of $74,880,000.
• Supplemental Aeration of the North and South Branches of the Chicago River: CTE/AECOM explored the
technologies and costs for adding supplemental aeration to the NBCR and SBCR. The CAWs WQ Model was also
used to support this study. The study concluded that four stations, in addition to the existing aeration stations that
were installed by the District in 1980 at Devon Avenue and Webster Avenue on the NSC and NBCR, respectively,
would be required. The range of present worth costs is $47,700,000 million to $132,600,000 million, depending on
the aeration technology.
• Flow Augmentation and Supplemental Aeration of the South Fork of the South Branch of the Chicago River
(Bubbly Creek): CTE/AECOM investigated water quality management options for Bubbly Creek using the CAWs
WQ Model and determined that a combination of flow augmentation and supplemental aeration would improve
conditions in Bubbly Creek. The costs for the management options, depending upon the aeration technology, was
determined to range from $81,900,000 to $145,000,000.
• CAWs Habitat Evaluation and Improvement Study: In early 2007, the District initiated the planning and
development of a request for proposal for a comprehensive study of the varying habitats, including sediments,
throughout the CAWs, as well as identification of ambient fish populations and life stages. This information will
better define the capabilities of the CAWs to support aquatic life and resolve issues of its potential to support early
life stages of fish. Existing information on habitat is limited and information on early life stages non-existent. A
habitat metric specifically designed for this highly modified urban waterway system will be developed as the basis
for aquatic life use designations and expected improvements in aquatic life use due to proposed water quality
improvements will be assessed. This study is being conducted by LimnoTech. The field data collection phase was
completed in 2008 and the final report completed by mid-2009.
• Integrated Water Quality Strategy: The District is currently conducting engineering, cost, and water quality
studies to develop an integrated water quality strategy for meeting the proposed DO standards in R08-9. This study
is being conducted by CTE/AECOM Engineers, Inc., and integrates approaches such as flow augmentation,
supplemental aeration, and CSO capture and treatment, which were previously studied individually, into a unified
strategy for water quality improvement. The study also looks comprehensively at the entire CAWs including the
Chicago Sanitary and Ship Canal and the Calumet River System, which were not included in previous engineering
studies. Existing analysis by the District of potential water quality improvements only looks at treatment and
waterway restoration actions independently. This study is exploring the feasibility and effectiveness of
combinations of actions and will then analyze the economic costs. Current information does not consider combined
effects or combined costs. This study will be completed by spring 2009.
• Determination of Economic and Environmental Impact of Meeting Proposed Effluent Disinfection and
Dissolved Oxygen Standards: In conjunction with the integrated water quality strategy, the District will conduct
an economic feasibility assessment to determine the costs to implement the integrated treatment and stream
improvement projects given the District’s current economic structure, which has certain tax-based limitations. The
District initiated the study in 2007 to determine the overall costs and environmental impacts that will result from
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