Agenda - Council Work Session - 10/20/2020 - Special

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1.3 1.4 2 The combined capacity of all of the wells is 7,220 gallons per minute (gpm) which is equivalent to 10.4 million gallons per day (MGD). The firm capacity (capacity with the largest well out of service) is 5,770 gpm or 8_3 MGD_ If a central water treatment plant is constructed, Wells No. 1 and 2 will not likely be con nected to the water treatment plant. The firm capacity without considering Wells No. 1 and 2 is 4,850 gpm or 7.0 MGD, All of the wells are located in the southern part of the City north of U.S. Highway 10, with Wells No, 1 and 2 Iodated in the southeast portion of Ramsey, and Wells No. 3-8 located in the south- central portion of Ramsey. Maintenance records indicate that the wells, pumps, and motors are inspected and repaired on a routine basis. The condition of the wells, pumps, and motors appears to be good. Current Water Treatment Chlorine is also added to the well water to provide a disinfectant residual in the distribution system. The City utilizes a free chlorine residual in the distribution system rather than chloramine, which is a less powerful disinfecting agent created when chlorine is mixed with ammonia. The City does have low levels of naturally occurring ammonia in their well water, although chlorine is fed past the breakpoint to completely oxidize the ammonia. Polyphosphate is added to the water to sequester iron and manganese. Sequestering of iron and manganese keeps the metals in solution and prevents them from precipitating to form oxides, and thus preventing aesthetic water quality issues such as color, taste, and sedimentation. Sequestration does not remove iron or manganese, and polyphosphate degrades over tirne which may cause aesthetic issues at dead -ends and outer ends of the distribution system. In accordance with Minnesota State Statute, fluoride is also added lo the treatment process to promote strong teeth. The chemicals are added to the raw water from the wells in each of the pump houses prior to being pumped into the distribution system_ Existing Water Towers The City of Ramsey currently has three water towers with storage capacities of 0.5 MG, 1.5 MG, and 2.0 MG. The smaller two towers are located in the south part of town; while the largest tower is located in the northeast part of town. The 0,5 MG tower is a spheroid style steel water tower constructed in 1989, while the 1,5 MG and 2_0 MG towers are fluted column steel water towers constructed in 2000 and 2010, respectively. Distribution System Modeling A hydraulic computer model was generated to evaluate the performance of the City's current water distribution system, as well as evaluate the system into the future as the water system expands, experiences increasing demands, and utilizes a water treatment plant instead of individual wells pumping into the system. The model used the most recent GIS information for the City's water system assets, and was created using WaterGEIVIS®, a pipe network program developed by Bentley®. Flow testing was conducted within the distribution system in October FEASIBILITY STUDY -DRAFT RAMSY 154354 Page 2