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January 26, 2024 <br />Don Peterson <br />Page 4 of 21 <br />Reference: Water Quality Assessment of Silver View Pond, Mounds View, MN <br />Table 1. Operational grouping and recycling potential of phosphorus fraction. <br />Iron -bound P <br />Mobile P pool Loosely -bound P Biologically -labile and subject to mobilization through <br />biogeochemical and geochemical reactions. <br />Labile organic P <br />Non -mobile P pool <br />Aluminum -bound P <br />Calcium -bound P Biologically -refractory and subject to burial; not readily <br />available for biological uptake. <br />Refractory P <br />Sediment grab samples were also collected in the western forebay for sediment analysis for disposal option <br />considerations in the event that sediment dredging would be necessary. <br />RESULTS AND DISCUSSION <br />The following sections provide discussion of our findings from analysis of the water chemistry, aquatic <br />vegetation, and sediment chemistry data components of the water quality assessment in Silver View Pond. <br />Water quality <br />Table 2 shows the concentration range of water quality parameters collected this summer from Silver View <br />Pond. Minnesota does not have water quality standards for stormwater ponds, so we compared the Silver <br />View Pond data to the eutrophication standards for shallow lakes in the same ecoregion (North Central <br />Hardwood Forest) to gauge water quality under existing conditions. <br />Chlorophyll -a is a proxy for algal biomass and is an indicator of how productive the system is in response to <br />elevated nutrient concentrations. Both chlorophyll -a and TP exceed the limit for shallow lakes, indicating <br />very high productivity in Silver View Pond. Total nitrogen (TN) and total Kjeldahl nitrogen (TKN) are also <br />elevated. Nitrite/nitrate concentrations were below the reporting limit. TKN represents ammonia and organic <br />nitrogen, so these nitrogen data indicate that a large portion of the nitrogen pool is in an organic form. <br />Nutrient delivery to Silver View Pond will need to be reduced in order to improve water quality and reduce <br />frequency and duration of algal blooms. <br />Design with community in mind <br />