Changes

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 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.

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.

==Recent Performance Research==

==Recent Performance Research==

[[File:OGS types Lee, 2014 update.PNG|thumb|400px|Shown here are the two variations of hydrodynamic separators ([[Oil and grit separator]]s) used in the 6-year study conducted by Lee, et al., 2014. All four OGS' used were of different sizes. The first (Type A) was a dip cylindrical plate with a centershaft and the second (Type B) was a hollow cylindrical screen. All four sites where the OGS' were installed were in urban settings in Gyunggi Province, Korea, and discharge into Gyung-An stream, which deposits into the Pal-dang Lake. This lake is the the primary drinking water source for Seoul's Metropolitan area (Lee, et al. 2014<ref>Lee, D.H., Min, K.S. and Kang, J.H., 2014. Performance evaluation and a sizing method for hydrodynamic separators treating urban stormwater runoff. Water science and technology, 69(10), pp.2122-2131)</ref>]].

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

**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>).

<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>).

 

** 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://pubmed.ncbi.nlm.nih.gov/24845330/ (Lee, et al. 2014) - Performance evaluation and a sizing method for hydrodynamic separators treating urban stormwater runoff.]

*[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.]

**This study conducted performance monitoring over a 6-year period (137 separate storm events) of four different hydrodynamic separators in Korean urban catchments between 2006 - 2012. Removal rates were relatively low at all four sites (1. Roadway site: Avg. Inflow = 239.32 mg/L vs Avg. Outflow = 122.2- mg/L /  2. Residential site:  Avg. Inflow = 59.74 mg/L vs Avg. Outflow = 50.35 mg/L / 3. Roadway Site: Avg. Inflow = 62.50 mg/L vs. Avg. Outflow = 33.76 mg/L / 4. Residential(63.5%) & Roadway (36.5%) CDA site: Avg. Inflow = 236.24 mg/L vs. Avg. Outflow = 160.54 mg/L). The low removal rates were due to high rates of extreme overflow events occurring with most suspended sediment being quite small/fine in nature (<75μm)(Lee, et al. 2014<ref>Lee, D.H., Min, K.S. and Kang, J.H., 2014. Performance evaluation and a sizing method for hydrodynamic separators treating urban stormwater runoff. Water science and technology, 69(10), pp.2122-2131)</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==