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January 26,2024 <br /> Don Peterson <br /> Page 20 of 21 <br /> Reference: Water Quality Assessment of Silver View Pond,Mounds View,MN <br /> Total cost of the bioretention features is estimated at$68,000. Table 11 summarizes the BMP pollutant <br /> reduction and cost-effectiveness. <br /> Table 11. CR H2 Bioretention Features Treatment Level and Cost-Effectiveness. <br /> BMP TSS TSS TSS TP Inflow, TP TP Cost- <br /> Inflow, Outflow, Reduction, lb/yr Outflow, Reduction, Effectiveness, <br /> lb/yr lb/yr lb/yr lb/yr lb/yr $/lb TP/yr <br /> Linear 3,144.40 1,294.80 1,849.60 10.30 7.40 2.90 $23,500 <br /> Bioretention <br /> Features <br /> Summary and Recommendations <br /> A water quality assessment of Silver View Pond was performed to develop recommendations for <br /> improvements in and around the pond to improve its water quality. The assessment included: <br /> • Field data collection of bathymetry, water quality, sediment chemistry, and aquatic vegetation <br /> • Water quality modeling of the pond watershed <br /> • Lake modeling of in-pond water quality <br /> • Assessment of pond vegetation <br /> • Assessment of sediment chemistry with a focus on phosphorus release <br /> • Development of recommendations for water quality improvements, including vegetation <br /> management, sediment management, internal nutrient load reduction, and external nutrient load <br /> reduction <br /> Recommended waterualit improvements are as follows: <br /> q P <br /> Y <br /> • Vegetation management: No interventions to manage the submerged aquatic vegetation are <br /> recommended, as the existing vegetation is native and provides ecological value to wildlife. <br /> Removal of submerged aquatic vegetation would likely result in a conversion to an algae- <br /> dominated system. Periodic skimming of duckweed and/or watermeal from the pond surface in late <br /> summer could aid in improving dissolved oxygen levels in the pond. <br /> • Sediment management: Sediment deltas are recommended to be removed at selected outlets to <br /> the pond. These would restore original pond depths. <br /> • Internal load reduction: A pilot alum application project using a water column stripping approach is <br /> recommended in the spring following ice-out but prior to growth of dense abundant vegetation. <br /> Follow-up monitoring of phosphorus and chlorophyll-a is recommended to determine if/when future <br /> alum dosing would be required. <br /> Design with community in mind <br />