11/13/2014. Overview. Past Research. Results from Current Research on Pollutant Export from Bioretention Systems and Next Steps

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Neil Glenn
5 years ago
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Chris May, Kitsap County Andy Rheaume, City of

Dylan Ahearn, Herrera Environmental Curtis

Herrera Environmental Overview Bioretention

specification developed in 2009 focused on

literature neglects flushing and compost-based

research 2013-14 Redmond builds 6 additional

conducts media optimization study 2013-14 Tacoma

Significant export of nitrate, phosphate, and

lysimeters (mesocosms) Good TSS, zinc, and

phosphate, and copper at year 1 Export of

1 Results from Current Research on Pollutant Export from Bioretention Systems and Next Steps Chris May, Kitsap County Andy Rheaume, City of Redmond Douglas Howie, Department of Ecology Dylan Ahearn, Herrera Environmental Curtis Hinman, Herrera Environmental John Lenth, Herrera Environmental Overview Bioretention encouraged in 2013 NPDES Permit Current specification developed in 2009 focused on hydraulics and plant health Bioretention WQ literature neglects flushing and compost-based systems Redmond and WSU monitoring indicates export 2013 Ecology issues bioretention restrictions and funds additional research Redmond builds 6 additional bioretention study systems Kitsap conducts media optimization study Tacoma studies WTRs in bioretention We report back today Past Research 185 th Extension Bioretention Project Good zinc capture Significant export of nitrate, phosphate, and copper Sampling from new systems WSU large-scale lysimeters (mesocosms) Good TSS, zinc, and bacteria capture at year 1 Export of nitrate, phosphate, and copper at year 1 Export of nitrate and copper stops at year 2 Good capture of nitrate and copper after year 2 Phosphate export continues Sampling began after test plots exposed to 1 water year 1

2 185 th Extension Bioretention Project 185 th Extension Bioretention Project 185 th Extension Bioretention Project 2

WSU Results WSU Results New Research Funding: Ecology Municipal Stormwater Grants of Regional or Statewide Significance Kitsap County: Analysis of Bioretention Soil Media for Improved Nitrogen,

3 WSU Results WSU Results New Research Funding: Ecology Municipal Stormwater Grants of Regional or Statewide Significance Kitsap County: Analysis of Bioretention Soil Media for Improved Nitrogen, Phosphorus, and Copper Retention Redmond: Analysis of Bioretention Soil Media for Improved Nitrogen, Phosphorus, and Copper Retention Tacoma: Treatment Media for Phosphorus Removal Goal: Improved bioretention soil media specificationthat minimizes pollutant export and maximizes WQ treatment 3

Six Full-Scale Bioretention Systems 185 th Street Extension Project = 2

Monitoring following the Technology Assessment Protocol Ecology (TAPE)

event and sample collection requirements MOC Comp: 60% sand, 40% compost MOC

Maple Valley Loamy Sand MOC Loam 2: Woodinville Loamy Sand 185 th Char/Comp:

4 Six Full-Scale Bioretention Systems 185 th Street Extension Project = 2 systems Maintenance and Operations Center Decant Facility (MOC) = 4 systems Monitoring following the Technology Assessment Protocol Ecology (TAPE) Continuous flow monitoring Flow weighted composite sampling Specific storm event and sample collection requirements MOC Comp: 60% sand, 40% compost MOC Char/Comp: 60% sand, 15% compost, 15% biochar, 10% shredded bark MOC Loam 1: Maple Valley Loamy Sand MOC Loam 2: Woodinville Loamy Sand 185 th Char/Comp: 60% sand, 15% compost, 15% biochar, 10% shredded bark 185 th Coir: 80% sand, 20% Coir 4

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Identify Candidate Media Components Literature Review Project Partner Input Screen Media Components for N, P, and Cu Leaching Synthetic Precipitation

good permeability Flush Media Treatments (8 treatments, 3 replicates) Permeability and falling head Dose Media Treatments Plant Growth Tests and Physical

A Better Media Blend? Percent Ingredient 1. 60/40 WS/Comp 2. 70/20/10 VS/Fe/DE 3. 70/20/10 VS/Fe/Ash 4. 70/20/10 VS/CP/DE 5. 70/20/10 VS/CP/GAC 6.

6 Identify Candidate Media Components Literature Review Project Partner Input Screen Media Components for N, P, and Cu Leaching Synthetic Precipitation Leaching Protocol (SPLP) Tests Develop Media Blends Minimal labile organic material content, high C/N ratio, high water holding capacity, pollutant capture, good permeability Flush Media Treatments (8 treatments, 3 replicates) Permeability and falling head Dose Media Treatments Plant Growth Tests and Physical Characteristics Ingredients Mineral Aggregate Volcanic Sand (VS) Washed Sand (WS) Organic Fraction Compost (Comp) Fe-fused wood chips (Fe) Coconut coir (CP) A Better Media Blend? Percent Ingredient 1. 60/40 WS/Comp 2. 70/20/10 VS/Fe/DE 3. 70/20/10 VS/Fe/Ash 4. 70/20/10 VS/CP/DE 5. 70/20/10 VS/CP/GAC 6. 70/20/10 WS/CP/Ash 7. 70/20/10 VS/CP/Ash 8. 90/10/L VS/Comp/AA layer High Performance Additive Diatomaceous earth (DE) High carbon fly ash (Ash) GAC (GAC) Activated Alumina (AA) 6

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Preliminary Conclusions Default BSM exhibits a prolonged flushing period for TSS, copper, and phosphorus Extremely high nitrogen flushing from default BSM at 185 th Extension Project was not

8 Preliminary Conclusions Default BSM exhibits a prolonged flushing period for TSS, copper, and phosphorus Extremely high nitrogen flushing from default BSM at 185 th Extension Project was not replicated New media components and blends exhibit less flushing than the default BSM Plant growth and pollutant capture characteristics of alternative media blends not known yet The underdrain design can reduce TSS flushing Ecology Perspective and Next Steps Step 1: Review data from new projects with project partners Step 2: Evaluate need for follow-up research Further refinements to optimize WQ treatment performance? Optimize media hydraulic performance? Develop sizing guidelines? Step 3: Update bioretention soil mix specification for SWMM Acknowledgements Washington State Department of Ecology Seattle University Seattle Public Utilities Washington State Department of Transportation 8

9 Questions 9

4/4/2012. Topics. Soil mixes for bioretention areas need to balance three primary design objectives for optimum performance: Bioretention Soil Mixes

4/4/2012. Topics. Soil mixes for bioretention areas need to balance three primary design objectives for optimum performance: Bioretention Soil Mixes Bioretention Soil Mixes Topics Composition Water Quality Issues Application Curtis Hinman WSU Extension and Bio Systems Eng. Faculty Low Impact Development Specialist chinman@wsu.edu Soil mixes for bioretention