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CITY COUNCIL WORK SESSION <br /> APPROVED <br /> 1 CITY OF LINO LAKES <br /> 2 MINUTES <br /> 3 <br /> 4 DATE : March 7, 2022 <br /> 5 TIME STARTED : 6:15 p.m. <br /> 6 TIME ENDED : 7:45 p.m. <br /> 7 MEMBERS PRESENT : Councilmember Stoesz, Lyden,Ruhland, <br /> 8 Cavegn and Mayor Rafferty <br /> 9 MEMBERS ABSENT <br /> 10 Staff members present: City Administrator Sarah Cotton; Community Development <br /> 11 Director Michael Grochala; City Engineer Diane Hankee; Director of Public Safety John <br /> 12 Swenson; City Clerk Julie Bartell <br /> 13 <br /> 14 (5:30 pm) The Rookery Activity Center(visit facility) <br /> 15 <br /> 16 1. Water Treatment Pilot Study, Greg Johnson and Ursinio Puga of WSB and <br /> 17 Associates Mr. Johnson reviewed the written report noting that in 2021 the council had <br /> 18 authorized WSB to complete the pilot study. Mr. Johnson added that the biological <br /> 19 filtration process being recommended is already being used effectively in several other <br /> 20 cities and has been utilized in Europe for decades. Mr. Johnson and Mr. Puga reviewed <br /> 21 a PowerPoint presentation that included information on: <br /> 22 <br /> 23 - Raw Water Quality—parameters for monitoring the water for pilot study; <br /> 24 focus on removing iron, manganese and ammonia from water; dissolved <br /> 25 oxygen and orthophosphate will also be discussed; <br /> 26 - What is Biological Filtration—microorganisms are already in the water and <br /> 27 need optimum conditions to get to the level to remove; other biological <br /> 28 filtration plants in the state; <br /> 29 - Conventional Filtration vs. Biological Filtration—comparison table; chemicals <br /> 30 are reduced by utilizing biological process; the rest of the process is same <br /> 31 minus some of the chemicals; <br /> 32 - Pilot Study Goals and Objectives; <br /> 33 - Pilot Plant Setup and Operation—view of pilot study testing machine used at <br /> 34 Well No. 6; two filter medias were compared; trailer was used for testing; <br /> 35 - Pilot Study Results—Found orthophosphate adequate; graph showing aeration <br /> 36 requirements; oxygen is added in the form of natural air; iron isn't a big goal <br /> 37 because it is already okay; ammonia results also graphed and reviewed; <br /> 38 - Financial Analysis—both treatment options include the same steps of treating <br /> 39 the water; with biological treatment chemicals are greatly reduced; graph <br /> 40 comparing costs for chemicals (inflated numbers used); Mr. Puga noted <br /> 41 information from another city that has already changed from conventional to <br /> 42 biological filtration and who experienced savings because of the rise in supply <br /> 43 costs; <br /> 1 <br />