Laserfiche WebLink
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 $68,000. Table 11 summarizes the BMP pollutant <br />reduction and cost-effectiveness. <br />Table 11. CR H2 Bioretention Features Treatment Level and Cost -Effectiveness. <br />BMP <br />TSS <br />TSS <br />TSS <br />TIP Inflow, <br />TIP <br />TP <br />Cost - <br />Inflow, <br />Outflow, <br />Reduction, <br />Ib/yr <br />Outflow, <br />Reduction, <br />Effectiveness, <br />Ib/yr <br />Ib/yr <br />Ib/yr <br />Ib/yr <br />Ib/yr <br />$/Ib TP/yr <br />Linear <br />3,144.40 <br />1,294.80 <br />1,849.60 <br />10.30 <br />7.40 <br />2.90 <br />$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 water quality improvements are as follows: <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 />