Keller Lake (Crystal Beach Park) Storm Water Quality Improvement Project

The Keller Lake Water Quality Improvement Project achieves the goals of the City of Burnsville, Black Dog Watershed Management Organization, and the Keller Lake TMDL by:-Achieving the City of Burnsville phosphorus removal requirement outlined in the Keller Lake TMDL by removing 78 lbs/yr-Utilizing remaining available land to construct a high performance, regional stormwater BMP-Providing a high profile water resource/stormwater educational opportunity in the frequently visited Crystal Beach Park-Retaining valuable open space in popular Crystal Beach Park by constructing the BMP undergroundKeller Lake (DNR ID: 19-0025-00) is listed on the 303(d) Impaired Waters List for nutrient impairment. Total Maximum Daily Loads (TMDLs) were established for Keller Lake following requirements set by the Minnesota Pollution Control Agency (MPCA) to achieve the eutrophication standards. The City of Burnsville is required to reduce overall loading of total phosphorus to Keller Lake by 74 lbs (47%) annually to meet the determined TMDL of 82 lbs/yr. Phosphorus sources for Keller Lake include stormwater runoff from the watershed and internal phosphorus from the lake sediment, plant life, etc. The proposed project site, as contained in the TMDL Implementation Plan, is Crystal Beach Park. This location contains both a 66-inch and 36-inch storm sewer that discharge untreated stormwater into Keller Lake. To remove phosphorus, the contaminant of concern, both storm sewer systems will be diverted to a treatment train consisting of pre-treatment isolator chamber with baffle walls, underground retention vault, and 1 cubic foot per second filter drawdown system to provide enhanced stormwater treatment prior to discharge back to the 66-inch trunk storm sewer and into Keller Lake. Due to the public perception of the existing Crystal Beach Park and the high volume of park visitors, underground storage and filtration is the ideal stormwater treatment BMP for phosphorus removal.