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Exhibit A <br /> EXHIBIT A <br /> Extended Period Simulation (EPS) <br /> Water System Modeling and Chlorine Residual Maintenance Plan <br /> The Consulting Engineer will provide the following Services to the City: <br /> 1. Participate in one project kickoff meeting with City to obtain project-related information,including <br /> the following, in native electronic formats: <br /> a. Chlorine sampling data collected throughout the distribution system from 2016 to present. <br /> b. Quarterly disinfection byproduct sampling for both total trihalomethanes (TTHM) and <br /> haloacetic acids(HAA5)from December 2016 to present. <br /> C. Target goals for minimum and maximum free chlorine residual at the high service pump <br /> discharge and at any point in the distribution system.City has identified its goal is to maintain <br /> 0.2 milligrams per liter (mg/L) free chlorine minimum in the distribution system and <br /> 0.4 mg/L free chlorine minimum in reservoirs and tanks in accordance with Illinois <br /> Environmental Protection Agency standards. <br /> d. Electronic mapping and description of water system upgrades that have occurred in the <br /> distribution system since the 2014 Water System Master Plan Update, including storage <br /> facilities,pumping facilities,pressure reducing valve stations,and significant water mains. <br /> e. Water system hourly demand, using automated meter readings and global positioning <br /> system coordinates for each system meter, and operational data, including tank levels, <br /> pump operation, pump discharge pressure, pump discharge flows, and related distribution <br /> system monitoring data for the minimum day flow in August 2017. <br /> 2. Update the existing water distribution system hydraulic model to reflect changes in the distribution <br /> system based on information provided by the City above. Additional static model calibration data <br /> will be collected through a change order to this Agreement, if needed. <br /> 3. Develop a water quality data collection and sampling protocol (Protocol) necessary for collection <br /> of data by City to calibrate an EPS model based on three operating days in August of 2018. Meet <br /> with City to review Protocol and update based on review comments as appropriate. <br /> 4. Assist City with carrying out and monitoring the Protocol in the field during normal business hours <br /> (7 A.M.to 4 P.M.)over a three-day site visit, not including travel time. <br /> 5. Calibrate the existing water system model in WaterGEMS for an EPS based on the August <br /> calibration data collected through the Protocol. Model will be primarily calibrated based on <br /> hydraulic operation of the distribution system with United Stated Environmental Protection Agency <br /> (USEPA) and American Water Works Association standards for EPS. A secondary calibration <br /> using the collected chlorine residual monitoring by the City will be conducted to assist in the <br /> evaluation of relative water age and chlorine residual concentrations within the distribution system. <br /> 6. Perform modeling of base scenarios for both water age and chlorine residual based on minimum <br /> day demands in August 2018. <br /> a. Model and demonstrate the results of one water age scenario and one chlorine scenario that <br /> represent the current configuration and operation of the water system. Base scenario will <br /> anticipate the actual chlorine concentration being distributed from the South Water <br /> Treatment Plant (SWTP) using the Protocol-collected data. Results will be demonstrated <br /> through water age and chlorine concentration figures for incorporation into a report. <br /> A-1 <br />