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6. FINANCIAL ANALYSIS <br />Instead of relying heavily on chemicals like other treatment methods, biological filtration relies on naturally <br />occurring microorganisms to treat water. Therefore, one of the main advantages of biological filtration is the <br />reduction of chemical usage which can result in significant chemical savings over time. In addition, <br />biological filtration produces less processed and more sustainable water due to the reduction of chemical <br />use. Biological filtration eliminates the need to feed chlorine upstream of the filters (prechlorination) to <br />oxidize iron and ammonia and the need to feed permanganate (potassium or sodium permanganate) to <br />oxidize manganese. Similar to conventional filtration, chlorine is still needed downstream of the filters for <br />disinfection purposes. In addition to chlorine, fluoride is also needed in the finished water. Orthophosphate <br />is sometimes also needed in the plant effluent for lead and copper corrosion control in the water distribution <br />system. <br />Figure 6-1 shows a 20-year projection of the annual water treatment chemical costs in Lino Lakes for a <br />conventional filtration facility and a biological filtration facility. Chemicals included in this analysis consist of <br />permanganate and chlorine. Fluoride and orthophosphate were not included in this analysis as both <br />chemicals may be needed in the same amount regardless of the treatment type used. The chemical cost <br />projection below includes a 3-percent inflation rate. <br />$90,000 <br />$80,000 <br />$70,000 <br />ig� $60,000 <br />2 <br />U$50,000 <br />CO <br />$40,000 <br />E <br />U$30,000 <br />$20,000 <br />$10,000 <br />2020 2022 2024 2026 2028 2030 2032 2034 2036 2038 2040 <br />Date <br />Conventional Filtration Biological Filtration <br />Figure 6-1. Chemical Cost Projection for Water Treatment <br />The chemical cost projection shown in Figure 6-1 is summarized in Table 6-1 below. As shown in the table <br />below, biological filtration has the potential of generating almost $950,000 in chemical savings over the next <br />20 years by eliminating the use of permanganate and prechlori nation. <br />Table 6-1. Cumulative Chemical Cost Projection <br />Year <br />Conventional <br />Treatment <br />Biological <br />Treatment <br />Cumulative <br />Savings <br />2020 <br />$ 34,405 <br />$ 6,738 <br />$ 27,667 <br />2030 <br />$ 476,597 <br />$ 96,718 <br />$ 379,879 <br />2040 <br />$ 1,192,271 <br />$ 242,339 <br />$ 949,932 <br />Water Treatment Pilot Study Report <br />Biological Removal of Ammonia, Iron and Manganese at Well House No. 6 <br />City of Lino Lakes, MN <br />WSB Project No. 0 18601 -000 Page 15 <br />