Changes

*[https://www3.epa.gov/region1/npdes/stormwater/research/epa-final-report-filter-study.pdf (USEPA, 2013) - Evaluation and Optimization of Bioretention Design for Nitrogen and Phosphorus Removal]

*[https://www3.epa.gov/region1/npdes/stormwater/research/epa-final-report-filter-study.pdf (USEPA, 2013) - Evaluation and Optimization of Bioretention Design for Nitrogen and Phosphorus Removal]

**USEPA conducted both field and laboratory testing on the performance of bioretention cells featuring filter media amended with drinking water treatment residuals with low solids content. Water treatment residuals were included at 10-15% of the total filter media mix by volume. Amended bioretention cells had median orthophosphate removal efficiencies of 90-99%. A second study found a bioretention design featuring WTR amended filter media and an [[Bioretention: Internal water storage|internal water storage zone]] optimized to remove phosphorus and nitrogen had an orthophosphate removal efficiency of 20% and effluent concentrations below 0.02 mg/L.

**USEPA conducted both field and laboratory testing on the performance of bioretention cells featuring filter media amended with drinking water treatment residuals (WTR) with low solids content (5-10% solids). Water treatment residuals were included at 10-15% of the total filter media mix by volume. Amended bioretention cells had median orthophosphate removal efficiencies of 90-99%. A second study found a bioretention design featuring WTR amended filter media and an [[Bioretention: Internal water storage|internal water storage zone]] optimized to remove phosphorus and nitrogen had an orthophosphate removal efficiency of 20% and effluent concentrations below 0.02 mg/L.

[[File:EBC vs. TBC.PNG|500px|thumb| Comparison of an Enhanced dephosphorization bioretention cell (EBC) (above) vs. a traditional bioretention cell (TBC) (below). The EBC includes evenly spaced apart soil mixture layers, which includes 70-80% native soil found on site mixed with 20-30% of charcoal, oregani matter and iron, along with permeable layers of gravel pumice and zeolite, all of which help adsorb phosphates out of stormwater entering the system. This differs from the TBC design which generally includes just a gravel bed to aid in the facility's drainage ability (Ho and Lin, 2022)<ref>Ho, C.C. and Lin, Y.X., 2022. Pollutant Removal Efficiency of a Bioretention Cell with Enhanced Dephosphorization. Water, 14(3), p.396. https://mdpi-res.com/books/book/5900/Urban_Runoff_Control_and_Sponge_City_Construction.pdf?filename=Urban_Runoff_Control_and_Sponge_City_Construction.pdf#page=168</ref>.]]

[[File:EBC vs. TBC.PNG|500px|thumb| Comparison of an Enhanced dephosphorization bioretention cell (EBC) (above) vs. a traditional bioretention cell (TBC) (below). The EBC includes evenly spaced apart soil mixture layers, which includes 70-80% native soil found on site mixed with 20-30% of charcoal, oregani matter and iron, along with permeable layers of gravel pumice and zeolite, all of which help adsorb phosphates out of stormwater entering the system. This differs from the TBC design which generally includes just a gravel bed to aid in the facility's drainage ability (Ho and Lin, 2022)<ref>Ho, C.C. and Lin, Y.X., 2022. Pollutant Removal Efficiency of a Bioretention Cell with Enhanced Dephosphorization. Water, 14(3), p.396. https://mdpi-res.com/books/book/5900/Urban_Runoff_Control_and_Sponge_City_Construction.pdf?filename=Urban_Runoff_Control_and_Sponge_City_Construction.pdf#page=168</ref>.]]