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January 26, 2024 <br />Don Peterson <br />Page 14 of 21 <br />Reference: Water Quality Assessment of Silver View Pond, Mounds View, MN <br />additional benefits in addition to the spring application. If the application strategy is deemed successful, <br />annual or semi-annual applications may be needed until nutrient loading has been significantly reduced <br />from the watershed. <br />Based on the sediment phosphorus chemistry data, we have calculated an alum dose that is appropriate for <br />a water column stripping dose in Silver View Pond, along with estimated material cost per application. Note <br />that these unit prices do not include contractor mobilization and demobilization. Additionally, alum unit <br />prices are subject to market fluctuations, so $3.25 /gallon of alum is based on our experience with alum <br />treatment projects of small and large scales in Minnesota. Stantec can support the City with development <br />of technical specifications and bid documents, and contractor selection when ready to move forward with <br />the pilot application. <br />Table 7. Alum Dose and Cost Estimates <br />* Subject to market fluctuations <br />External load reduction <br />P8 modeling was used to estimate TP loading to Silver View Pond. Based on modeling results, BMPs were <br />then designed to treat runoff from the subwatersheds with the highest loading rates. The modeling results <br />and BMP design are presented below. <br />Subwatershed Modeling <br />Figure 6 shows the subwatersheds defined along with the estimated annual TP loadings, based on P8 <br />modeling. As indicated on Figure 6, primary TP loadings to Silver View Pond are occurring at: <br />• The forebay on the western edge <br />• From Lake Court Drive along the north side of the pond <br />• From the H2 Flats apartments on the southeast side of the pond <br />• From County Road H2 on the southwest edge of the pond <br />Design with community in mind <br />