1. New Retrofit Technologies for Stormwater Treatment Andy Erickson, Research Fellow St. Anthony Falls Laboratory May 18, 2011

2. http://stormwater.safl.umn.edu/ Minnesota Filter Trenches (Prior Lake, MN) Photo Courtesy: A. Erickson

3. http://stormwater.safl.umn.edu/ Minnesota Filter Permeable Weir Photo Courtesy: VLAWMO and EOR

4. http://stormwater.safl.umn.edu/ Minnesota Filter Ditch Check Dams (under development) http://www.dfr.state.nc.us/water_quality/wqglossary.htm http://www.cpluhna.nau.edu/Change/waterdevelopment2.htm http://www.casfm.org/stormwater_committee/LID-Summary.htm

5. http://stormwater.safl.umn.edu/ Minnesota Filter Ditch Check Dams (under development) Longitudinal Profile Minnesota Filter Coarse Aggregate Natural Soil

6. http://stormwater.safl.umn.edu/ “Minnesota Filter” (e.g., sand with 5% iron filings, Maplewood, MN) Photo Courtesy: A. Erickson

7. http://stormwater.safl.umn.edu/ © Finance & Commerce SAFL Baffle

8. http://stormwater.safl.umn.edu/ Photo Courtesy: A. Erickson

9. http://stormwater.safl.umn.edu/

11. Conclusions There are technologies available for stormwater retrofits –Minnesota Filter for dissolved pollutants –SAFL Baffle for suspended sediment There are many retrofit opportunities in MN and beyond

12. http://stormwater.safl.umn.edu/ Iron Enhanced Sand Filter, Prior Lake, MN (photo courtesy A. Erickson) Questions? For more information, contact: Andy Erickson (eric0706@umn.edu) http://stormwater.safl.umn.edu/