Field Performance of Two Stormwater Bioretention Filtration Design Configurations Andrew Anderson, E.I.T. North Carolina State University Department of Biological & Agricultural Engineering 2013 Annual Regional Stormwater Conference Charlotte, NC Like us on Facebook facebook.com/ncstatestormwaterextension @NCSUstormwater
Courtesy Arkansas LID Manual
Stormwater Control Measure Toolbox Bioretention Vegetated swales Green roofs Rainwater harvesting Permeable pavement Sand filter Catch basin insert Stormwater wetlands Detention/retention ponds What about in series? Proprietary devices?
Stormwater Proprietary Devices New systems introduced faster than researchers can research them. How well do they compare to traditional BMPs? Numerous and varying testing protocols across U.S. Unique opportunity between municipality, manufacturers, and independent Universities to implement field-scale studies.
Filterra Bioretention System High-flow surface runoff filter Open-throat inlet ideal for curb flow Proprietary soil media with tree planter Courtesy: www.filterra.com
Filterra BioPave TM Stormwater System Courtesy: www.filterra.com
BioPave TM Treatment Train Surface Inflow Permeable Pavement (PICP) Filterra To traditional storm drainage network Flow/WQ Flow/WQ Flow/WQ Performance Evaluation: PICP (in) PICP (out) PICP (out) Filterra (out) PICP (in) Filterra (out) LID Processes Filtration Infiltration LID Processes Filtration Bio processes Sorption Evapotranspiration
Fayetteville, NC Raleigh Asheville Charlotte Fayetteville Wilmington Fayetteville Characteristic Value Annual Precipitation (in.) 45 Avg. Precipitation Days (>0.01 in) 111 Avg. Inter-Event Time (d) 3 to 4 10-yr, 24-h storm (in.) 5.52 Population (2010 Census) 374,157 www.bae.ncsu.edu/stormwater Map Data source: http://www.secretary.state.nc.us/kidspg/geog.htm Climate Data source: http://en.wikipedia.org/wiki/fayetteville,_north_car olina#geography
Research Site Amtrak Station 0.13-acre drainage area 100% impervious ~270:1 Loading Ratio Amtrak Train Station www.bae.ncsu.edu/stormwater
Stand-Alone Filterra Surface inflow from aging asphalt parking lot Media filtration and treatment Outflow drainage to existing storm sewer Sized for the 10-yr storm Courtesy: www.filterra.com www.bae.ncsu.edu/stormwater
Stand-Alone Filterra Sizing Courtesy: www.filterra.com www.bae.ncsu.edu/stormwater
Stand-Alone Filterra Construction
Stand-Alone Filterra Construction
Stand-Alone Filterra Construction
Stand-Alone Filterra Monitoring Equipment
Filterra BioPave TM PICP Area = 2,300 sf Runon Area = ~5000 sf (~2:1 ratio)
Design Cross-Section 4 No. 57 Opengraded base 2 No. 8 Stone 3 1/8 Concrete pavers No. 2 Subbase Subgrade 4 perforated underdrain Concrete check dam
Construction of PICP
Construction of PICP Specify AND verify..washed stone!!!
Construction of PICP Monitoring wells Concrete check dams
Construction of PICP Screed #8 stone Fill joints with #8 Compact #2 stone
Finished PICP Surface
Tree filter / bioretention install
Tree filter / bioretention install INLET (FROM PICP) OUTLET (TO STORM DRAIN)
Tree filter / bioretention install Outflow of tree filter connects to existing storm network
Monitoring Goals 1. Evaluate water quality and hydrologic treatment performance of both PICP-Filterra and standard Filterra proprietary devices a) North Carolina b) Virginia 2. Collect hydrologic data of PICP SCM for use in calibration of DRAINMOD
Monitoring Metrics Event Mean Concentrations (EMCs) Phosphorus (Total, Dissolved, Ortho-P) Nitrogen (TKN, NOx, Ammonia, TN, Total & Diss.) Total Suspended Solids Suspended Sediment Concentration Particle Size Distribution Specific Gravity Copper and Zinc (Total & Dissolved) ph Hydrology Flow rate Total volume time metrics
Preliminary Monitoring Results n < 15 for all water quality parameters Rainfall events sampled Range = 0.18 to 2.08 in. Median = 0.6 in.
BioPave TM Hydrology (PICP Portion) 93% Cumulative Volume Reduction Median volume reduction 98% (Range 88-100%) Median peak time delay ratio = 9.1 (past targets for bioretention of 6 1 ) www.bae.ncsu.edu/stormwater 1 Davis, A. P. (2008). Field Performance of Bioretention: Hydrology Impacts. Journal of Hydrologic Engineering, 13(2), 90.
Preliminary Monitoring Results Sediment, Standalone Unit TSS TSS (EPA Method #160.2) SSC (ASTM Method D 3977-97) Differences in sampling and analysis (SSC includes more sand-sized particles) Consistently low sediment in outflow (filtration mechanism) OutEMC = 3.733 + 1.950(P) Pr > t = 0.3348
Preliminary Monitoring Results Nitrogen Species, Standalone Unit NO 2/3 -N TN Excellent 1 Excellent 1 Inlet Outlet 1 McNett, J. K., Hunt, W. F., and Osborne, J. a. (2010). Establishing Storm-Water BMP Evaluation Metrics Based upon Ambient Water Quality Associated with Benthic Macroinvertebrate Populations. Journal of www.bae.ncsu.edu/stormwater Environmental Engineering, 136(5), 535 541.
Low Nutrient Influent Loadings (North Inlet) Total Nitrogen Total Phosphorus
Preliminary Monitoring Results Phosphorus Species, Standalone Unit TP TDP OutEMC = 0.041 (P) Pr > t = 0.951 Ortho-P OutEMC = 2.7E 02 1.8E 17(P) Pr > t = 0.122
Preliminary Monitoring Results Phosphorus Species, Standalone Unit McNett, J. K., Hunt, W. F., and Osborne, J. a. (2010). Establishing Storm-Water BMP Evaluation Metrics Based upon Ambient Water Quality Associated with Benthic Macroinvertebrate Populations. Journal of www.bae.ncsu.edu/stormwater Environmental Engineering, 136(5), 535 541.
Preliminary Monitoring Results Metals, Standalone Unit Copper Zinc
Buffering Effect of Amtrak Retrofits www.bae.ncsu.edu/stormwater
Preliminary Monitoring Results Particle Size Distribution, Standalone Unit www.bae.ncsu.edu/stormwater
Low Nutrient Influent Loadings (North Inlet) Why?
Preliminary Monitoring Results NO 2/3 -N TN TKN TP TDP TSS Standalone Filterra Permeable Pavement -66% 30% 41% 28% 90% -130% 7% 33% 32% 82%
Conclusions Influent concentrations LOW for Filterra Opportunity to examine effluent concentrations relative to ambient water quality standards Volume reduction and filtration hypothesized to provide additional benefits Standalone device sediment, metals removal (% basis) is high ph buffering seems apparent Load reductions observed for both systems BioPave load reduction appears greater than standalone system
Field monitoring can be challenging Maintenance is key to permeable pavement component City cooperation is key in field projects Not all urban watersheds are created equally Lessons Learned
References ASTM Standard D448. (2008). Standard Classification for Sizes of Aggregate for Road and Bridge Construction, ASTM International, West Conshohocken, PA, 2008, DOI: 10.1520/D0448-08. Brown, R.A., Skaggs, R.W, Hunt, W.F. (2013). Calibration and Validation of DRAINMOD to Model Bioretention Hydrology. Journal of Hydrology, 486, 430-442. Gee, G.W. and J.W. Bauder. (1995). Particle-size analysis in A. Klute (ed.) Methods of Soil Analysis, Part 1. Physical and Mineralogical Methods. Soil Science Society of America, Madison, WI. p. 383-411. NC DENR (2007). Chapter 18: Permeable Pavement (rev. 2012) in Stormwater Best Management Practices Manual. North Carolina Department of Environment and Natural Resources, Division of Water Quality. Smith, D. R. (2011). Permeable Interlocking Concrete Pavements. 4 th ed. Interlocking Concrete Pavement Institute, Montreal, Canada. Barrett, M.E., Lantin, A. and Austrheim-Smith, S. (2004). Stormwater pollutant removal in roadside vegetated buffer strips. Transport Res. Rec. 1890: 129-140. McNett, J. K., Hunt, W.F., and Osborne, J.A. (2010). Establishing storm-water BMP evaluation metrics based upon ambient water quality associated with benthic macroinvertebrate populations. J. of. Env. Eng. 136: 535-541.
Acknowledgements William Hunt, Professor, NC State University Shawn Kennedy, Research Technician Filterra Bioretention Systems Greg Caison, City of Fayetteville Mayowa Lewis, City of Fayetteville Al Hardee, City of Fayetteville Amtrak staff, Fayetteville, NC Linda McKenzie & Jenny James, NCSU Center for Applied Aquatic Ecology
Thanks! Any Questions? www.bae.ncsu.edu/stormwater Like us on Facebook facebook.com/ncstatestormwaterextension @NCSUstormwater www.bae.ncsu.edu/stormwater