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January 26,2024 <br /> Don Peterson <br /> Page 10 of 21 <br /> Reference: Water Quality Assessment of Silver View Pond,Mounds View,MN <br /> Silver View Pond <br /> Upper 5 cm —25th Percentile --Median —75th Percentile <br /> 0.50 <br /> 0.45 <br /> 0.40 <br /> a) 0.35 <br /> aa) <br /> E 0.30 <br /> a- 0.25 <br /> x <br /> -0 0.20 <br /> m <br /> IX 0.15 <br /> 0.10 <br /> 0.05 11-111 . <br /> 0.00 <br /> 1 2 3 <br /> Sampling Station <br /> Figure 4. Concentrations of redox-sensitive phosphorus in the upper 0-5 cm of sediments collected <br /> from Silver View Pond. <br /> Phosphorus Budget <br /> A major objective of the water quality diagnostic assessment includes development of a phosphorus mass <br /> balance model for Silver View Pond that estimates the proportion of phosphorus loads from the watershed <br /> drainage area and from internal sediment release. Determination of the relative magnitude of external <br /> versus internal phosphorus loading serves to inform management strategies to reduce phosphorus <br /> concentrations in Silver View Pond. To accomplish this objective, Stantec developed a P8 model (described <br /> in more detail below)to simulate phosphorus loads to Silver View Pond from the surrounding drainage <br /> area. The loads from P8 were input into a lake response mass balance models to determine the relative <br /> proportion of external versus internal phosphorus loading. <br /> Internal load estimates were based on the direct measurements of phosphorus release rates under oxic <br /> and anoxic conditions (in units of mg/m2-d). Extrapolation up to whole-lake loads requires an estimate of the <br /> areal extent of anoxic and oxic conditions, which can be estimated for polymictic small shallow lakes based <br /> on an anoxic factor(AF)model developed by Gertrud Nurnberg5. <br /> 5 Nurnberg, Gertrud. 2009. Accessing internal phosphorus load—problems to be solved. Lake and Reservoir <br /> Management 25(4):419-432. <br /> Design with community in mind <br />