Changes

==TSS Reduction==

==TSS Reduction==

[[File:TSS - permeable pavement.JPG|200px|thumb]]

[[File:TSS - permeable pavement.JPG|200px|thumb]]

The performance results for [[Permeable Pavement]]/[[Porous Asphalt: Life Cycle Costs]] practices, located within TRCA's watershed originate from three primary sites:  

The performance results for [[Permeable pavement]]/[[Porous Asphalt: Life Cycle Costs]] practices, located within TRCA's watershed originate from three primary sites:  

*Kortright Centre Parking Lot

*Kortright Centre Parking Lot

*Seneca College

*Seneca College

[[File:TP - permeable pavement.JPG|200px|thumb]]

[[File:TP - permeable pavement.JPG|200px|thumb]]

==Phosphorus Reduction==

==Phosphorus Reduction==

The performance results for [[Permeable Pavement]]/[[Porous Asphalt: Life Cycle Costs]] practices, located within TRCA's watershed originate from three primary sites:  

The performance results for [[Permeable pavement]]/[[Porous Asphalt: Life Cycle Costs]] practices, located within TRCA's watershed originate from three primary sites:  

*Kortright Centre Parking Lot

*Kortright Centre Parking Lot

*Seneca College

*Seneca College

The mean performance value recorded at the outlet for Permeable Pavement practices' ability to remove Total [[Phosphorus]] (TP) was calculated based on 300 separate recordings between 2005-2007, and 2010-2017 amongst the three sites previously mentioned.

The mean performance value recorded at the outlet for Permeable Pavement practices' ability to remove Total [[Phosphorus]] (TP) was calculated based on 300 separate recordings between 2005-2007, and 2010-2017 amongst the three sites previously mentioned.

As can be seen in the corresponding boxplot, the mean performance removal efficiency of the bioretention practices monitored are not meeting the acceptable upper extent range of nutrients as of 0.03 mg/L (30 µg/L) (Environment Canada, 2004<ref name="example1">Environment Canada. (2004). Canadian guidance framework for the management of phosphorus in freshwater systems. Ecosystem Health: Science‐based solutions report no. 1–8. Cat. No. En1–34/8–2004E. </ref>; OMOEE, 1994<ref>Ontario Ministry of Environment and Energy (OMOEE), 1994. Policies, Guidelines and Provincial Water Quality Objectives of the Ministry of Environment and Energy. Queen’s Printer for Ontario. Toronto, ON.</ref>).

As can be seen in the corresponding boxplot, the mean performance removal efficiency of the permeable pavement practices monitored are not meeting the acceptable upper extent range of nutrients as of 0.03 mg/L (30 µg/L) (Environment Canada, 2004<ref name="example1">Environment Canada. (2004). Canadian guidance framework for the management of phosphorus in freshwater systems. Ecosystem Health: Science‐based solutions report no. 1–8. Cat. No. En1–34/8–2004E. </ref>; OMOEE, 1994<ref>Ontario Ministry of Environment and Energy (OMOEE), 1994. Policies, Guidelines and Provincial Water Quality Objectives of the Ministry of Environment and Energy. Queen’s Printer for Ontario. Toronto, ON.</ref>).

The median value of the 355 samples taken was '''0.04 mg/L''' whereas the mean was '''0.08 mg/L''', with an '''62%''' guideline exceedance. Given the age of most of these practices, more inspection, maintenance and necessary rehabilitation will be needed to ensure they are able to meet the federal and provincial governments' guideline requirement for stormwater quality.

The median value of the 355 samples taken was '''0.04 mg/L''' whereas the mean was '''0.08 mg/L''', with a '''62%''' guideline exceedance. Given the age of most of these practices, more inspection, maintenance and necessary rehabilitation will be needed to ensure they are able to meet the federal and provincial governments' guideline requirement for stormwater quality.

'''Please refer to the [[Phosphorus]] page and the [[additives]] page for more information on how LIDs can reduce contaminant loading in stormwater'''

'''Please refer to the [[Phosphorus]] page and the [[additives]] page for more information on how LIDs can reduce contaminant loading in stormwater'''

==Recent Performance Research==

==Recent Performance Research==

*[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://www.waterrf.org/system/files/resource/2020-11/DRPT-4968_0.pdf International Stormwater BMP Database: 2020 Summary Statistics (Clary et al. 2020)]

**USEPA conducted both field and laboratory testing on the performance of bioretention with augmented designs and filter media composition with aluminum hydroxide/oxide content, found normally within water treatment residuals. These additives added at 10-15% of the total filter media mix ad median removal efficiencies of 90-99% of orthophosphate and a second study found a bioretention design with WTR mixture in the filter media and a [[Bioretention: Internal water storage|IWSZ]] optimized to remove phosphorus and nitrogen had a removal efficiency of 20% and effluent concentrations below 20µg/L (well below the MECP/CCME guideline in Ontario).

**The International Stormwater Best Management Practices (BMP) Database is a publicly accessible repository for BMP performance monitoring study, design, and cost information.  As of December 2019, the BMP Database contains data sets collected over four decades from over 700 BMP studies through the U.S., Canada, Sweden, New Zealand, Australia, China, etc. that are accessible on the project website ([www.bmpdatabase.org]). The performance data for both TSS and TP are as follows within the report:

***Median TSS value of outflow/effluent of stormwater from P.P is 22 mg/L in comparison to 77 mg/L influent levels. These levels are computed using the BCa bootstrap method described by Efron and Tibishirani (1993). This value is below the required CWQG levels for TSS in stormwater.

***Median Total phosphorus (TP) value of outflow/effluent of stormwater from P.P is 0.10 mg/L in comparison to 0.17 mg/L influent levels. These levels are computed using the BCa bootstrap method described by Efron and Tibishirani (1993). This value is below the required federal (Environment Canada, 2004) and provincial (OMOEE, 1994) levels for TP in stormwater ((Clary et al., 2020<ref>Clary, J., Jones, J., Leisenring, M., Hobson, P. and Strecker, E. 2020. International stormwater BMP database 2020 summary statistics. Water Environment & Reuse Foundation.</ref>).

*[https://www.mdpi.com/2073-4441/14/3/396 (Ho and Lin, 2022) - Pollutant Removal Efficiency of a Bioretention Cell with Enhanced Dephosphorization]

[[File:BMP mapping tool.PNG|thumb|500px|One of STEP's sites located in Mississauga, ON. (Lakeview Neighbourhood), where P.P was installed in residential driveways. Full submission and details to the BMP can be selected on the map viewer and can be viewed [https://igeowater.com/InternationalBMPDBAssets/PDF/Description/00608--DESCP.pdf here.] (International Stormwater BM<P Database, 2021<ref>International Stormwater BMP Database. 2021. BMP Mapping Tool. Retrieved Feb. 28, 2023. https://bmpdatabase.org/bmp-mapping-tool</ref>).]]

**Authors Ho and Lin, 2022 note that bioretention practices perform poorly in reducing phosphorus from influent stormwater when compared to their ability to remove ammonia and COD pollutants. The authors tested a new type of enhanced dephosphorization bioretention cell (EBC) which improves phosphorus removal performance. The difference between EBC and a traditional bioretention cell is that the lowest level of an EBC feature is comprised of a mixed fill material layer (permeable layers - PLs and soil mixed layers - SMLs) instead of a traditional gravel bed layer. The SMLs include active charcoal powder, organic matter and iron, evenly spaced apart, while the PLs include aggregates of gravel, pumice and zeolite. Over the two years that the same sized EBC feature was monitored in comparison to a standard bioretention cell they found that the EBC outperformed the traditional bioretention cell by removing 92% of total phosphorus to 52%. The average inflow concentration for both features from May 2019 - April 2021 was 0.76 mg/L, whereas the outflow concentration averages were 0.36 mg/L for the traditional bioretention cell and 0.06 mg/L for the EBC, respectively (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>.

*[https://sustainabletechnologies.ca/app/uploads/2019/06/improving-nutrient-retention-in-bioretention-tech-brief.pdf (STEP, 2019) - Improving nutrient retention in bioretention - Technical Brief]

*[https://www.sciencedirect.com/science/article/abs/pii/S0959652618335376 (Xie, et al. 2019) - Permeable concrete pavements: A review of environmental benefits and durability.]

**STEP researchers developed a study to examine the effectiveness of reactive media amendments as a means of enhancing phosphorus retention in a bioretention cell draining a 1150 m² parking lot in the City of Vaughan. For testing purposes, the bioretention was divided into three hydrologically distinct cells: (1) with a high sand, low phosphorus media mix (control); (2) with a proprietary reactive media (Sorbitve™) mixed into the sandy filter media, and (3) with a 170 cm layer of iron rich sand (aka red sand) below the sandy filter media. Outflow quantity and quality from each cell was measured directly, while inflows and runoff quality were estimated based on monitoring of an adjacent asphalt reference site over the same time period. The results found that the Sorbitve™ and the Iron rich (red) sand cells had lower concentrations of Total Phosphorus (among other contaminants) in its effluent outflow, and the TP measured was below the CCDME guideline of 0.03mg/L in both years monitored for Sorbitve™ (2016 & 2017) and 2017 for the cell with Iron rich (red) sand. Both cells had median concentrations lower than the control media cell used in the study by at least 68% for TP (STEP, 2019<ref>STEP. 2019. Improving nutrient retention in bioretention - Technical Brief. Prepared by Toronto and Region Conservation Authority. Published in 2018. https://sustainabletechnologies.ca/app/uploads/2019/06/improving-nutrient-retention-in-bioretention-tech-brief.pdf</ref>.

** This literature review paper looked at a multitude of studies highlighting the numerous benefits (hydraulic/water quality performance, heat-island mitigative effects, skid resistance ability and winter durability) associated with P.P and discussed some prominent papers' results. A project in Yakima, Washington (Yakima County website, 2012<ref>Yakima County website, 2012. Regional Stormwater Management Program, Project. Low Impact Development Demonstration Project. http://www.yakimacounty. us/stormwater/LID/project.htm.</ref>) compared effluent water samples collected in vaults adjacent to two pavement types (permeable and impermeable). The water samples collected from the P.P plot had significantly lower TSS values when compared to the control, impermeable plot's samples (25 mg/L vs. 320 mg/L). Whereas, Luck et al. (2008<ref>Luck, J.D., Workman, S.R., Coyne, M.S. and Higgins, S.F. 2008. Solid material retention and nutrient reduction properties of pervious concrete mixtures. Biosystems engineering, 100(3), pp.401-408.</ref>, 2009<ref>Luck, J.D., Workman, S.R., Coyne, M.S. and Higgins, S.F. 2009. Consequences of manure filtration through pervious concrete during simulated rainfall events. Biosystems Engineering, 102(4), pp.417-423.</ref>) found P.P to exhibit excellent mitigating characteristics for intensive, nearby agricultural practices (composted beef cattle manure) to help limit the amount of soluble phosphorus and total phosphorus in stormwater runoff (Xie, et al. 2019<ref>Xie, N., Akin, M. and Shi, X., 2019. Permeable concrete pavements: A review of environmental benefits and durability. Journal of cleaner production, 210, pp.1605-1621</ref>).

*[https://www.researchgate.net/publication/332063360_Enhanced_Nutrients_Removal_in_Bioretention_Systems_Modified_with_Water_Treatment_Residual_and_Internal_Water_Storage_Zone/download (Qiu, et al. 2019) - Enhanced Nutrients Removal in Bioretention Systems Modified with Water Treatment Residual and Internal Water Storage Zone]

*[https://www.sciencedirect.com/science/article/abs/pii/S0043135419308450 (Ostrom and Davis, 2019) - Evaluation of an enhanced treatment media and permeable pavement base to remove stormwater nitrogen, phosphorus, and metals under simulated rainfall.]

**Researchers from Beijing University and Auburn University, conducted lab experiments with two bioretention columns (1) with Water treatment residuals (WTRs - i.e. polyaluminium chloride & dewatered sludge from a surface water treatment plant) (15% dried weight, the remaining 85% sandy loam) and the second (2) filled with traditional sandy loam for its filter bed material. Their pollutant rmeova lefficiency for TSS was virtually the same, treating between 100 - 400 mg/L over 10 separate test cycles in a 50-day period. The effluent TSS levels were bot hless than 20 mg/L (10 mg/L less than the CCME requirement in Ontario) with removal percentages above 90% on average to a maximum of 97%. Meanwhile, for Total Phosphorus removal (TP) the column with 15% WTRs added boated a mean TP removal of 99.6% with a maximum effluent of 0.08 mg/L after remoting an average influent concentration load of 4.0 – 7.0 mg/L) (Qiu, et al. 2019)<ref>Qiu, F., Zhao, S., Zhao, D., Wang, J. and Fu, K., 2019. Enhanced nutrient removal in bioretention systems modified with water treatment residuals and internal water storage zone. Environmental Science: Water Research & Technology, 5(5), pp.993-1003.</ref>.

**This article by Ostrom and Davis, 2019, out of the University of Maryland discusses a new treatment media that can be developed to improve dissolved pollutant removal and retention in permeable pavement practices. This structural media is called "High Permeability Media Mixture (HPMM)", and was designed as a base material for P.P practices that can retain phosphorus in stormwater that enters the practice. The results of this study showed that effluent total dissolved phosphorus (TDP) levels was lower than influent for all samples (12 storms). Removal efficiency was between 48 - 98% effective with a median effluent level of 0.045 - 0.05 mg/L (dependent upon the 3 configurations used) in comparison to TDP event mean concentrations of 0.22 mg/L (Ostrom and Davis, 2019<ref>Ostrom, T.K. and Davis, A.P. 2019. Evaluation of an enhanced treatment media and permeable pavement base to remove stormwater nitrogen, phosphorus, and metals under simulated rainfall. Water research, 166, p.115071.)</ref>.

==References==

==References==