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EXHIBIT A (To'nsultants SCOPE OF ENGINEERING SERVICES CITY OF NORTH OLMSTED, OHIO SOUTH INTERCEPTOR INFILTRATION/INFLOW STUDY It is our understanding that the City intends to utilize their existing FLO-DAR and Sigma meters. FLO-DAR meters have a better accuracy under open channel flow conditions, and lesser accuracy under surcharged conditions. This is due to the fact that the meter switches from radar technology to AN probe technology during surcharge conditions. Radar technology is considered to have a +/-5% accuracy where an A/V probe can be +/- 15%. The Sigma A/V meters have an accuracy of +/-15%. While the City has indicated that the interceptor has surcharged under large rainfall events (exceeding 2" of rainfall), the interceptor generally has open channel flow with possible localized surcharge locations. If during the study a large event surcharges the interceptor, the flow metering will be collecting data through A/V probes. This makes meter location important for developing 1/1 impacts on a linear system. Upon review of the preliminary flow meter locations and the flow data provided by the City, there are 2 metering locations that we suggest may require further review based on wet weather peak flow observations by the City. The peak flow difference between the meter locations identified as M1 and M2 appear to have a difference ratio of less than 2, as well as meter locations M4 and M5. The City currently owns 8 FLO-DAR and 4 Sigma 910 meters. Four of the FLO-DAR meters are currently utilized as billing meters, but the City is open to moving them as needed. The City has staff fully trained in the installation, operation and maintenance of their meters and plans to utilize them during the metering period, however the existing equipment requires manual downloads. Due to increased efficiency and reliability, we suggest the City consider temporarily renting wireless communication data loggers for this study. The City also requires rain gauges for this study. The City is in the process of obtaining 2 rain gauges and will utilize rainfall data from the Hopkins Airport and the local NEORSD rain gauges as a backup sources during the study. An essential part of our project approach is being able to team with the City staff to ensure data integrity during the monitoring period. CT has a fully developed flow monitoring program that allows us to assist municipalities with their flow metering needs. As the metering program fully develops for this project, CT will be able to assist the City during any stage of the program with our own trained flow metering team. Prepared by CT Consultants, Inc. I November 9, 2017