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��M Exhibit A-3 Page <br /> City of Decatur,IL <br /> Ellen and Division I&I Reduction Program <br /> Once the critical storm duration has been identified, up to five (5) alternatives for eliminating actual <br /> and predicted SSOs will be evaluated using the calibrated and verified hydraulic model. These <br /> options will be discussed with the City of Decatur once mechanisms of flooding are understood, and <br /> will continue once all parties are in agreement with these options. Alternatives are likely to include <br /> storage (online or offline), upsizing the collection system to improve conveyance capacity, reducing <br /> Rainfall Dependant Inflow and Infiltration (RDII), and different combinations of alternatives. It should <br /> be noted that upsizing sewers is unlikely to be a feasible solution for the following reasons: <br /> • The existing Sanitary District of Decatur(SDD) interceptor sewers likely cannot provide significant <br /> additional capacity <br /> • The Florian Basin (Target Area 6) is located downstream of the Ellen/Division area.Any <br /> availability capacity in the existing SDD interceptor sewers may be needed for the future Florian <br /> Basin work. <br /> Cost benefit graphs will be provided in order to summarize and compare the costs of different levels <br /> of storm protection. <br /> Deliverables <br /> • Hydraulic and Hydrologic Modeling Analysis and Results(see Task 8—Report) <br /> Task 2: SMOKE TESTING <br /> Smoke testing is undertaken to identify inflow sources, such as roof drains, catch basins, yard and <br /> area drains, and cross-connections between storm and sanitary sewers systems. The smoke is <br /> forced out of any openings or connections to the sanitary sewer. Inspectors observe the test area for <br /> signs of smoke,which indicate potential defects or illegal connections. AECOM will work with City <br /> personnel to determine the smoke testing schedule. Based on our measurements of existing City GIS <br /> data, the Ellen/Division project area is comprised of approximately 25,000 lineal feet of sanitary <br /> sewer. This entire area (up to a maximum of 25,000 lineal feet)will be smoke tested. Smoke testing <br /> equipment will be charged at$125/day. <br /> Services for the smoke testing will be provided as follows: <br /> 1. Smoke testing will be performed by forcing a non-toxic, non-staining gray smoke into the sanitary <br /> sewer system with dual portable air blowers. For this project, Smoke#3C by Superior Signal <br /> Company(or equal)will be utilized. <br /> 2. AECOM's standardized smoke testing forms will be completed for each set-up and observed <br /> defects documented. Our smoke testing data report includes the following information: <br /> • Technicians performing the test <br /> ■ Date of the test <br /> ■ Manholes into which smoke is introduced into the sanitary sewer system <br /> • A sketch of each test site including: <br /> -Street names <br /> -Manhole numbers <br /> -Actual emission locations <br /> -Potential emission locations <br /> • Video and photographic documentation <br />