CWF 2012 – Iron Enhanced Sand Filter Project

Project Overview

In collaboration with the University of Minnesota St. Anthony Falls Laboratory, City of Stillwater and MN DNR Waters and Fisheries, an iron-enhanced sand filter was designed to remove approximately 118 pounds of total phosphorous per year from an area of Stillwater that drains to McKusick Lake and ultimately to the St. Croix River.

The project is located in the Settler's 5th Addition off of Morgan Ave in Stillwater.

The project will reduce phosphorous from a contributing drainage area of 1,200 acres by harvesting stream water from an offline constructed settli...ng pond. Stream flow will fill the settling pond to a designated elevation above the intake pipe at which time the pump will convey flow into the existing pretreatment cell of the pond. After pretreatment, the stormwater will flow through the iron-enhanced sand filter, and discharge back to the tributary stream through a newly constructed outlet structure.

The project was installed October 2013. The first year of operation in 2014 was used to learn optimal performance of the system and make any necessary final installation modifications. Performance monitoring will continue for the next several years.