Construction and Monitoring Performance of Filterra and BioPave TM Units in Fayetteville, NC Andrew R. Anderson, M.S., EIT Extension Associate North Carolina State University Department of Biological & Agricultural Engineering 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 (250-350 cm/h) Open-throat inlet ideal for curb flow Proprietary soil media with tree planter Courtesy: www.filterra.com 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 (mm) 1,143 Avg. Precipitation Days 111 Avg. Inter-Event Time (d) 3 to 4 10-yr, 24-h storm (mm) 140 Population (2010 Census) 374,157 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 Installed Sept. 2012 0.25-acre drainagearea 100% impervious ~270:1 Loading Ratio Amtrak Train Station
Stand-Alone Filterra Surface inflow from aging asphalt parking lot Media filtration and treatment Outflow drainage to existing storm sewer Throat sized for the 10-yr storm
Stand-Alone Filterra Sizing *Re-surveyed area larger than originally thought Courtesy: www.filterra.com
Filterra BioPave TM PICP Area = 2,300 sf Runon Area = ~5000 sf (~2:1 ratio) Installed Sept. 2012
Design Plan View Check dam Underdrain 4 x4 Tree Filter
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
To SW drainage network INLET (FROM PICP) OUTLET (TO STORM DRAIN)
Utilities Traffic loading 62,400 lifetime ESALs Rel. High Slope Soil parameters California Bearing Ratio (CBR) of 7-13 Soil texture = sand/sandy loam K sat = 0.25-0.5 cm/h Constraints Courtesy: Tomorrow Lab L.L.C.
Soil Excavation Avoid compaction of soil with heavy machinery as much as possible Preserve infiltration rate Fayetteville install: wanted less infiltration because of research Could compact or line if infiltration too high for research purposes BE CONSERVATIVE
Subgrade Preparation Ensure slope is correct (laser level, total station, etc.) Install check dams Concrete Filter fabric + No. 57 Stone
Concrete Edging
To Upturn or Not To Upturn? Generally: Yes in NC to store the Water Quality Volume Fayetteville Project: Goal was to also send water to the tree bioretention filter, so No upturn was used.
Make sure quarry supplies washed stone!
Finished PICP Surface
Tree filter / bioretention install Single Tree Planting
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 Monitoring Period from winter 2012 to present To date: Fully analyzed sediment and hydrologic performance for Stand-alone, nutrients on-going. 2. Collect hydrologic data of PICP SCM for use in calibration of DRAINMOD
Hydrologic Monitoring Multiple depth piezometers to see what s happening to zones Monitoring drain time performance throughout study and/or PICP lifespan Continuous rainfall at both sites HOBO U20 Water Level Logger, Onset Computer Corporation
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 Copper and Zinc (Total & Dissolved) ph Infiltration Rate of PICP Hydrology Flow rate Total volume time metrics Monitoring Metrics
Water Quality Sampling: North End (1) Standalone Filterra Inflow ISCO 6712 Compound weir Bubbler flow module Rainfall
Water Quality Sampling: North End (2) Standalone Filterra Outflow ISCO 6712 ISCO 6712 Bubbler flow module Cipoletti weir
Water Quality Sampling: South End (3) Inflow (sheet flow) ISCO 6712 Slot drain Rainfall paced
Water Quality Sampling: South End (4) PICP Outflow/ Filterra Inflow ISCO 6712 30 V-notch weir Bubbler flow module
Water Quality Sampling: South End (5) Filterra Outflow ISCO 6712 45 V-notch weir Bubbler flow module
PICP Clogging Monitoring Can use ASTM C1781 for permeable paver systems single 300-mm diameter ring infiltrometer
If Draining Impermeable Lot, Ensure It Is Clean! Maintenance is key! (more to come in the next presentation) Stabilized catchment Leaf litter from tree overhang Clogging! Old asphalt lot / PICP interface
PICP Clogging Monitoring Can use ASTM C1781 for permeable paver systems Extremely old and gritty lot draining to pavers can be a maintenance issue Anecdotal evidence from this and other studies on upperlimit of contributing area
PICP Clogging Monitoring Accounted for reduced volume infiltration based on a clogging factor Restorative Maintenance (March 2014)
Sediment Monitoring Data Characteristics SEASON TSS Sample No. Winter 4 2 Spring 9 6 Summer 6 6 Fall 3 1 Total 22 15 SSC Sample No. Parameter Average Rainfall (in.) Max rainfall depth (in.) WQ Events Only 0.72 0.52 1.94 4.94 Hydrologic events Max intensity (in/h) 0.48 5.28 22 water quality events captured 103 hydrologic events captured
Filterra Hydrology Metric Median Value Inflow Peak (cfs) 0.33 Outflow peak (cfs) 0.082 Peak Ratio 0.47 Peak Flow Reduction 53% Peak flow reduction most noticeable for small storms Did not increase peak flow (pre vs. post)
Filterra Hydrologic Budget Metric Median Value Inflow Peak (cfs) 0.33 Outflow peak (cfs) 0.082 Peak Ratio 0.47 Peak Flow Reduction 53% Peak flow reduction most noticeable for small storms Did not increase peak flow (pre vs. post) Inflow Outflow Bypass Other Total Volume (cubic feet) 44,691 34,106 8,361 2,190 Percent of Inflow (%) NA 76% 19% 6%
Filterra Hydrology
Filterra Sample Runoff Hydrographs
Filterra Capture Thresholds Outflow from Filterra = underdrain + bypass Rational equation for preand post-construction (forested vs. paved) for various intensities
Filterra Capture Thresholds
Filterra Capture Thresholds
Preliminary Phosphorus Statistics Parameter Median EMC (mg/l) Median Load (mg) All Storms (n = 21) TAPE (n = 9) Low Phosphorus Inflow? Influent Effluent Influent Effluent Median TP from typical 0.07 a** 0.038 parking a** lot 0.20 (Passeport b** et 0.048 al, b** 2009) 1.14 c ** 0.14 c ** 1.14 d ** 0.32 d **
Monitoring Results: Filterra Total Suspended Sediment Metric Parameter TSS SSC Concentration Inlet mean (mg/l) 125 95 Outlet mean (mg/l) 4.9 4.3 Conc. Perc. Reduction (all storms) Median 94% 96% Conc. Perc. Reduction (storms without bypass) Event-based load reductions (all storms) Event-based loadreductions (storms without bypass) Median 96% 96% Median 79% 82% Median 96% 96% Cumulative load efficiency (all storms) 76% 79% Cumulative load efficiency (no bypass) 96% 96%
Monitoring Results: Filterra Effluent Concentrations are Important!
Monitoring Results: Filterra Particle Size Distribution Storm event Date Feb. 26, 2013 Mar. 04, 2013 Mar. 19, 2013 Mar. 29, 2013 Jun. 10, 2013 PSD Collected at Inlet? June 12, 2014 X X X X X X PSD Collected at Outlet? Jun. 26, 2013 X X July 02, 2013 X X Aug. 13, 2013 Sep. 2, 2013 X X Sep. 21, 2013 Nov. 1, 2013 Feb. 19, 2014 Apr 15, 2014 X X Apr. 19, 2014 X X X X X
BioPave TM Water Quality: TSS Loading (Mg/ ha-yr) 1000 900 800 700 600 500 400 300 200 100 0 TSS Parking Lot Underdrain Outflow Surface Inflow Permeable Pavement (PICP) Filterra
BioPave TM Water Quality: 14 TN TN Load Reduction (kg/ha-yr) 12 10 8 6 4 2 0 PICP Filterra BioPave Surface Inflow Permeable Pavement (PICP) Filterra
BioPave TM Water Quality: 2.5 TP TP Load Reduction (kg/ha-yr) 2 1.5 1 0.5 0 PICP Filterra BioPave Surface Inflow Permeable Pavement (PICP) Filterra
BioPave TM Water Quality EMC: Total Nitrogen (Data 2012 May 2014) 0.69 mg/l Excellent WQ marker in the Piedmont for TN (McNett et al, 2010) Site Median TN EMC (mg/l) Runoff 0.83 PICP UD 0.81 Outflow 0.72
BioPave TM Water Quality EMC: Total Phosphorus (data from 2012-May 2014) 0.06 mg/l Excellent ambient water quality (McNett et al, 2010) Site Median TP EMC (mg/l) Runoff 0.069 PICP UD 0.043 Outflow 0.035
Median Concentrations of Other Pollutants (as of May 2014) Pollutant Inflow (mg/l) Outflow (mg/l) Ammoniacal Nitrogen-N 0.10 0.06 Nitrate/nitrite-N 0.11 0.15 TKN 0.90 0.42 Total Nitrogen 1.07 0.52 Total Phosphorus 0.07 0.04 Orthophosphate-P 0.03 0.03
Low Nutrient Influent Loadings for Stand-Alone Filterra.Why?
Conclusions Filterra device statistically treated 1 storms, and showed similar outflow to pre-development conditions Filterra sediment EMC efficiencies of 95%+ and load reductions of 75%+ Clogging is an issue with dirty, large contributing areas
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 NCSU Stormwater Engineering Group Filterra Bioretention Systems City of Fayetteville Linda McKenzie & Jenny James, NCSU Center for Applied Aquatic Ecology Amtrak TM staff
Thanks! Any Questions? Andrew Anderson, E.I.T. arander5@ncsu.edu 919-515-8595 Like us on Facebook facebook.com/ncstatestormwaterextension @NCSUstormwater