Compost Amended Biofiltration Swale: A New Tool to Remove Dissolved Metals Paula Hammond Steve Reinmuth Secretary of Transportation Chief of Staff

Presentation by Mark Maurer PLA, PE 2012 Sustainable Stormwater Symposium – Portland, OR September 19, 2012 Presentation Overview

• Goals of the study • Site and study design • Construction • Field observations • Results Goals of the study

• Develop an end of pipe treatment to removed dissolved metals (enhanced treatment) • Develop BMP that can be used to easily retrofit existing facilities Vicinity Map

Project site

Photo source – Google Earth Site Design

Photo source – WSDOT Photogrammetry

Site Plans Site Preparation Site Preparation Site Preparation – Compost Application

Depth gauge Site Preparation - Hydroseeding

Detail of mulch & seed coverage Observations - Vegetation

Composted bioswale (above)

Control bioswale (right) Observations - Vegetation

Control bioswale (above)

Composted bioswale (left) Compost vs control (crest gauge in cut section)

Composted bioswale Control bioswale Compost vs control (crest gauge in fill section)

Composted bioswale Control bioswale Testing Parameters

• Total suspended solids (TSS) • Total and soluble reactive phosphorous • Total Kjeldal nitrogen (TKN) • Nitrate+nitrite nitrogen • Hardness • Total and dissolved copper • Total and dissolved zinc • pH Results – TSS

Swale Storm Influent TSS Effluent TSS TSS Removal Events (mg/L) (mg/L) Efficiency (%)

Control 16 22 – 203 5.3 – 20 72 – 95 (median = 107) (median = 12) (median = 86)

Compost- 16 11 – 159 0.8 – 7.5 84 – 98 amended (median = 91) (median = 5.0) (median = 94)

17 Results – Dissolved Copper

Swale Storm Influent Dissolved Effluent Dissolved Dissolved Cu Events Cu (mg/L) Cu (mg/L) Removal Efficiency (%) Control 16 0.0037 – 0.0195 0.0043 – 0.0116 -49 – 43 (median = 0.0064) (median = 0.0067) (median = -6.7)

Compost-amended 16 0.0036 – 0.0145 0.0043 – 0.0116 -44 – 74 (median = 0.0060) (median = 0.0067) (median = 25)

Compost-amended 9 0.0060 – 0.0145 0.0031 – 0.0068 14 – 74 (influent ≥ 0.006 mg/L) (median = 0.0070) (median = 0.0043) (median = 37)

18 Results – Dissolved Copper

BMP Type n Median Dissolved Cu Removal (%) Filterra 23 44 Ecology Embankment 10 39.2 Compost-Amended 9 – 16 25 – 37 Biofiltration Swale Wet Pond 56 33 Biofilter – Grass Strip 151 20 Wet Vault 29 19 Filter – Sand 78 14 Biofilter – Grass Swale 86 7 Control Biofiltration Swale 16 -6.7

19 Results – Dissolved Zinc

Swale Storm Influent Effluent Dissolved Zn Events Dissolved Zn Dissolved Zn Removal (mg/L) (mg/L) Efficiency (%)

Control 16 0.038 – 0.108 0.013 – 0.151 -71 – 72 (median = (median = 0.037) (median = 20) 0.051)

Compost- 16 0.039 – 0.111 0.005 U – 0.016 69 – 91 amended (median = (median = 0.009) (median = 83) 0.051)

20 Results – Dissolved Zinc BMP Type n Median Dissolved Zn Removal (%) Compost-Amended 16 83 Biofiltration Swale Ecology Embankment 24 78.7 Filter – Sand 85 73 Biofilter – Grass Strip 177 66 Filterra 23 54 Wet Pond 85 50 Biofilter – Grass Swale 88 38 Control Biofiltration 16 20 Swale Wet Vault 33 11

21 Results – Total Petroleum Hydrocarbons (TPH)

Swale Storm Influent TPH Effluent TPH TPH Removal (mg/L) (mg/L) Efficiency (%) Events Control 15 0.95 – 4.78 0.29 – 2.55 8 – 92 (median = 3.39) (median = 1.25) (median = 62)

Compost- 15 1.28 – 10.5 0.11 – 1.72 42 – 97 amended (median = 2.29) (median = 0.38) (median = 84)

22 Results – Total Reactive Phosphorus (TRS)

Swale Storm Influent TRS Effluent TRS TRS Removal (mg/L) (mg/L) Efficiency (%) Events Control 16 0.003 – 0.066 0.003 - .132 -214 - 40 (median = (median = .008) (median = -67) 0.007) Compost- 16 0.002 – 0.023 0.223 – 0.860 -11,700 - -3639 amended (median = (median = 0.290) (median = -6595) 0.006)

23 Technology Approval Protocol - Ecology Acknowledgements

• Steve Burges, University of Washington • Rhonda Brooks, WSDOT Research Office • David Batts, was with WSDOT, now with King County • WSDOT Staff Development Office • Rebecca Dugopolski, Herrera • John Lenth, Herrera

Questions?

Mark Maurer PLA, PE WSDOT Highway Runoff Program Manager [email protected] 360-705-7260 http://www.wsdot.wa.gov/Environment/WaterQuality/Runoff/HighwayRunoffManual.htm