The Potential to Enhance Nutrient Removal in Bioretention and Sand Filters

Transcription

1 The Potential to Enhance Nutrient Removal in Bioretention and Sand Filters

2 Welcome to the Webcast To Ask a Question Submit your question in the chat box located to the left of the slides. We will answer as many as possible during Q&A. To Answer a Poll Question Simply select the preferred option. For those viewing this session alongside several colleagues, respond in a manner that represents your organization as a whole. We ARE Recording this Session All comments and questions will be recorded and included in the archives. We will notify you as soon as the recording and related resources are loaded on the web. We Appreciate Your Feedback Fill out our evaluations our funders need to hear it!

3 Chesapeake Bay Stormwater Training Partnership To learn how you can have access to: FREE Webcasts Free 1-day design, inspection & maintenance workshops Intensive master stormwater seminars Direct On-site technical assistance Self guided web-based learning modules Visit:

4 Upcoming Webcasts Thursday, Nov 3: The Pond Protocol Thursday, Nov 17: Newly approved Urban Tree Canopy Credit Thursday, Dec 8: Other Perspectives on Research on LID Performance Enhancement Register here:

5 Poll Question #1 How many people are watching with you today? Just me 2-5 people 6-10 people > 10 people

6 Poll Question #2 Tell us a little about yourselves who are you representing today? Local government Private sector Regulatory agency Non-profit Academia Other tell us in the chat box

7 Poll Question #3 Tell us how this webcast is relevant to you: I design stormwater BMPs I inspect/maintain/track BMPs I am a planner and use BMPs to account for load reductions I am a researcher I am generally interested in the topic Other

8 Speaker Info Dave Hirschman Hirschman Water & Environment, LLC Bryan Seipp Center for Watershed Protection, Inc. Cecilia Lane Chesapeake Stormwater Network

9 Today s Agenda 1. Project Overview 2. Overview of Literature Review Findings on Performance Enhancing Devices for Stormwater BMPs 3. Field Monitoring of Biochar Amendments 9

10 Some Background Pollutant removal credit assigned to BMPs based on the amount of runoff capture treated per impervious acre and type of BMP Performance Standards & Retrofit EP Memos Ongoing research about tweaking designs to target specific pollutants Multiple requests/inquiries about increasing credits given based on design modifications

11 General Approach Conduct an extensive major review and analysis of the recent literature on mechanisms to enhance the nutrient removal performance of existing low impact development (LID) practices Confer with key researchers in the field about their research and demonstration projects Make a decision whether the existing research supports an increase in the baseline N and/or P removal rates for bioretention and related runoff reduction practices, as a result of design enhancements from the current BMP specification

12 Design Modifications Alternative media layers (e.g., iron filings, activated carbon, wastewater treatment residuals, activated carbon, biochar, wood chips, fly-ash) Internal design configurations that promote denitrification (e.g., upturned elbows, carbon seeding, anaerobic layers, subsurface ponding, biofilms, controlled subsurface releases) LID treatment train combinations (e.g., bioretention to submerged gravel wetlands), and Plant species to maximize nutrient uptake and/or evapotranspiration rates.

13 The review examined the individual and combined effect of these four factors in increasing nitrogen and phosphorus removal rate within bioretention areas and other selected LID practices

14 Next Steps Today s webcast: Overview of literature review and preliminary monitoring data collected by CWP December 8 Webcast: Other Perspectives on Research of LID Performance Enhancement Early 2017 Recommendations for Crediting PEDs in the Chesapeake Bay Watershed

15 Performance Enhancing Devices for Stormwater BMPs Literature Review & Recommendations Chesapeake Stormwater Network David J. Hirschman Hirschman Water & Environment, LLC

16 Presentation Overview Generations of Bioretention Design & Performance PEDs Research Review Reactive Media Amendments for bioretention, sand filters BMP Configurations: internal water storage, sizing/storage Vegetation

17 Generations of BMP Design & Performance Generation of Bioretention Design 1990s: Early Bioretention 2000s: Mainstreaming Bioretention Late 2000s to present: Statespecific standards and Chesapeake Bay Performance Curves General Nutrient Removal Rates Limited TP removal around 25%, with leaching of dissolved P Moderate TN removal: 55%, but negligible or negative capture of dissolved N TP: 45-75%, but very wide range of results, including negative removals TN: 25-70% TP: 55-90% TN: 45-90% Are We Ready For A 4 th Generation With PEDs?

18 PEDs Research Review 138 papers, journal articles, technical reports Stormwater-focused + agricultural & wastewater applications Half of nutrient-oriented studies were for bioretention Many studies in lab, where variables can be controlled; about 30% of nutrient studies in field Many studies since 2010 PEDs are growing research area Geographically distributed in Australia, U.S., New Zealand, and other countries

19 Bioretention: Typical Some Vegetation Soil Media With High Sand Content Freely-Drained: Underdrains near bottom

20 Bioretention: With PEDs Vegetation with dense coverage above & below + periodic harvesting Soil Media With Reactive Amendments Underdrain system with Internal Water Storage

21 Other PEDs Size/storage enhanced runoff reduction Optimized storage with automatic controls Graphic: Marcus Quigley, Opti,

22 Removal Efficiency (%) Focus of PEDs Research: Improved Performance for Particulate & Dissolved Forms 150 Bioretention Removal Efficiencies TSS TP Sol P TN NOx Cu Zn Bacteria

23 Laboratory: Multiple Columns or Mesocosms to control multiple variables & flow rates Photos: Virginia Tech Research Station, Virginia Beach: Mesocosms Testing Various Bioretention Soil Media Recipes & vegetation, Liu et al Thanks to

24 Field: Real-World Conditions Photo: Bill Hunt, North Carolina State University, Bio&Ag Engineering, Stormwater:

25 1. Reactive Media Amendments Metal Cations: Iron/Aluminum, Calcium/Magnesium Carbon: Biochar, activated carbon* Adsorption of Dissolved P onto reactive surface Removal factors: reactive surface area, contact time, adsorption capacity & lifespan, ph of media * Compost is typically used as a component of bioretention soil media, but also is a source of leaching of nutrients

26 Metal Cations: Materials Tested Water treatment residuals Steel wool, iron filings Slag Acid mine drainage residuals Fly ash TARGET POLLUTANT: Dissolved P

27 Steel Wool Iron Filings ~½ inch thick ~C33 Concrete Sand Source: Andy Erickson, Saint Anthony Falls Laboratory, Univ. of Minnesota

28 MN (Iron Enhanced) Filter (5% iron filings, Maplewood, MN) Source: Andy Erickson, Saint Anthony Falls Laboratory, Univ. of Minnesota

29 Water Treatment Residuals Photo Credit: Washington Stormwater Center

30 Summary of Field Research on Iron Amendments Bioretention & Stormwater Filters Source Material P Removal * Roseen & Stone 2013; Stone WTR % Liu and Davis, 2013 WTR 60 84% Ahmed et al. Iron filings 65% 2014 Erickson et al.2012 Iron filings 29-91% Erickson and Gulliver 2010 Iron filings 72-90% Erickson et al Steel wool 80-90% *Ranges for Total P and Dissolved P

31 Considerations for Mass Deployment Hydraulic conductivity, clogging: research shows good results for Fe, but not Ca. Some concern with WTR if it is not processed/dried. Leaching of metals (e.g., Al): research shows that it is potential concern if ph < 5, generally not an issue for stormwater applications. Construction costs: MN examples had 3-5% increase, but lessons will be learned in C.B. Watershed.

32 Carbon -- Biochar Photo Credit: UC Davis Biochar Database Many Types: Biomass used Combustion temperature Size/surface area Porosity As Media Amendment: Adsorption of P & N C donor for denitrification

33 Lab Findings for Biochar & Other Carbon Sources Source Material 1 P Removal N Removal Beneski 2013 Biochar N/A 50% Tian et al Biochar 37-74% Kim et al Various carbon % sources Reddy et al Biochar 47% 3 86% Al-Anbari 2008 GAC, zeolite 20-60% % Schang et al Zinc-coated GAC 80-90% %

34 2. BMP Configurations a) Internal Water Storage (IWS) b) Sizing/Storage/Optimization

35 2.a. Internal Water Storage (IWS) Organic N & Ammonia Anaerobic Zone Nitrogen Gas Nitrate Outflow Creation of a Saturated Zone Graphic: Bill Hunt, North Carolina State University, Bio&Ag Engineering, Stormwater:

36 WV Stormwater Manual

37 Looking down into the Overflow Basin

38 Nitrogen is Complicated! (slide source: Alan Davis, Fifty Shades of Green, 2014)

39 Field Research on IWS Source P Removal N Removal Roseen & Stone 2013; 20-55% % 1 Stone 2006 DeBusk & Wynn % 2 99% 2 Brown & Hunt 2011 N/A >50% Gilchrist et al % 2 Passeport et al % % 2 Winston et al Negative removals due to organic content in media 1 Range of values show removals for Total P or N and Dissolved P or N. 2 Mass load reduction with a majority of reduction attributable to runoff reduction processes.

40 Lab Research on IWS Source P Removal N Removal Roseen & Stone 2013; 50-99% 1 N/A Stone 2006 Caruso % (47-67% for no IWS) 43-92% (negative for no IWS) Zhang et al >70% 83% Zinger et al IWS increased Dissolved N removal 1.8 to 3.7X from no IWS, but also decreased P removal Glaister et al % % (negative for no IWS) Lucas & Greenway 2011b N/A 53-94% 1 (negative to 50 for no IWS) 1 Range of values show removals for Total P or N and Dissolved P or N.

41 Considerations for Mass Deployment Trade-off with storage MAY lead to more storms by-passing if storage is taken up with IWS. Others studies show IWS enhances runoff reduction. SOME studies showed decreased P removal with IWS, especially if IWS intersects soil media with organic content. Should be paired with excellent vegetation plan and management.

42 2.b. Sizing/Storage/Optimization Photo Credit: Marcus Quigley, Opti,

43 Research Shows: Generally high levels of Runoff Reduction, even with underdrained systems. Conventional systems can leach (increased concentration at outlet), but good Runoff Reduction leads to mass load reductions anyway. Increase cell size to 4.5 to 8.3% of D.A. to fully replicate forested stream hydrology (Olszewski & Davis 2013). SIZE & STORAGE MATTER!

44 Runoff Reduction Rocks the BMP! Infiltration Canopy Interception Evaporation Transpiration Rainwater Harvesting Extended Filtration Center for Watershed Protection

45 State Stormwater Performance Standards State Regulatory Performance Standard 1 BMP Performance Credit 1 DC On-site retention of runoff from 1.2 rainfall Runoff Volume reduction DE Zero effective impervious for 2.7 rainfall (Resource Protection Event, RPE) Runoff Volume Reduction MD On-site retention using ESD of runoff from 1.0 rainfall Runoff Volume Reduction OR Impervious CN Reduction NY VA On-site retention of runoff from 90 th percentile rainfall (~ 1 ) Total Phosphorus Load Limit of 0.41 lbs/ac/yr (performance based on management of runoff from 1.0 rainfall) Runoff Volume Reduction Total TP Load Reduction (Runoff Volume + Pollutant Removal) WV On-site retention of runoff from 1.0 rainfall Runoff Volume Reduction 1 Some states may include watershed specific pollutant load reduction requirements for select parameters, e.g., TP or TSS, in addition to volume reduction.

46 3. Vegetation

47 Research Shows: Type of vegetation is important: factors include root thickness/density, coverage, above & below-ground biomass, leaf area, etc. Vegetation plays a role in other performance measures: microbial activity in media (immobilization of nutrients), hydraulic performance, etc. Periodic harvesting may help with nutrient removal from system. Not much insight on C.B.-specific plants. Some to consider: Carex, Switchgrass, Big Bluestem, Joe Pye Weed, some trees with high stomatal conductance.

48

49

50 Bioretention: Typical Thick, Dense, Above & Below-Ground Biomass Source of Graphic: Claudia West, North Creek Nurseries, Some Vegetation Soil Media With High Sand Content Freely-Drained: Underdrains near bottom

51 Vegetation Results (selected) Source Vegetation P Removal/Retention Henderson Various 85-94% 2008 (31-90% for non- Lucas & Greenway 2008 Barrett et al Read et al Scharenbroch et al Native grasses & shrubs from Australia Buffalograss, Big Muhly (native to TX) N Removal/Retention 63-77% (negative to 25% for vegetated) non-vegetated) 67-92% 51-76% (39-56% for nonvegetated) for non-vegetated (maximum of 18% 77-94% 59-79% (negative for nonvegetated) 20 Australian species From 2 to >150 fold change in removal for N and P, depending on species of vegetation. 7 tree species from the Midwest Study focused on water cycle and transpiration rather than nutrient removal; trees account for 46-72% of total water budget

52 Considerations for Mass Deployment BMP planting & maintenance plans have to become more sophisticated, including periodic harvesting. More work to I.D. good C.B. Watershed species (by State, eco-region?).

53 Bringing It All Together: Optimizing Design

54 Bringing It All Together: Optimizing Design Also: Li & Davis, 2014 Roseen & Stone, 2013 Erickson, 2012 Lucas & Greenway, 2010 Note: Authors suggest customizing design to site conditions & treatment objectives

55 Summary PEDs include: reactive media, IWS, enhanced vegetation. Sizing/storage/optimization also important; Runoff Reduction remains key performance metric. PEDs are new frontier for stormwater research: primarily lab, but also some field examples. Research indicates performance enhancements for reactive media & IWS. Conditions apply to applying enhanced credit.

56 Q&A

57 Photo Credit: biochar.ucdavis.edu Field Monitoring of Biochar A sneak peak

58 Monitoring Objectives Evaluate and document the procedures for incorporating Biochar into Stormwater Management BMPs (Bioretention & Sand Filters) Measure the impact to the performance of stormwater management BMPs to remove TN, TP, and TSS

59 Bethel Korean Presbyterian Church

60 Diamond Hills Community

61 Carroll County Maintenance Center

62 Monitoring Equipment

63 ISCO Equipment Category Item Unit Cost # Total Cost 3700 Sampler $2, $22, Core Items Flow Module (with battery) $4, $34, Interface Module $1, $12, Software (Flowlink) $2, $2, Propak Starter Kit $ $1, Extra Propak bags $ Spring Ring for AV Sensor (special order 4") $ $ Accessories Spring Ring for AV Sensor (8") $ Scissor Ring Kit (16-80") $ Suction Tube (with strainer) $ $ Connection Cable $ $2, Communication Cable $ $ External DC Source Cable $ $ Cost of required items from ISCO $78, Home Store Supplies Suction Line (price per 100') $ $0.00 Batteries $ $2, x4 treated landscape posts $10 16 $ Accessories Pressure treated plywood $30 10 $ Screws, hinges, misc lumber $150 1 $ Ancillary Costs $3, ISCO and Housing Total $81, Multi-meter (ph, Conductivity) $175 4 $ Other Multi-meter (electrical - for batteries) $30 4 $ Items 500 ml HDPE bottles (precleaned 12 pack) $70 80 $5, Supplies $6, Total Equipment $87, Totals Contingency 10% $8,767.60

64 Monitoring Set-up

65

66 Sampling Procedures

67 Diamond Hills Flow Flow mass balance is good Less than 6% difference between in and out for large storm at end of July 2016 Scatter at low end Initial moisture Is the underdrain still running? Available water storage capacity in sand media

68 Bethel Treatment Chemical Data * * *At the lower margins of TP and TS detection Effluent TN, NO3, TKN conc. statistically lower alpha = 0.05) Effluent TP conc. statistically higher alpha = 0.05) Effluent TS conc. no statistical difference Control is similar but no significant differences

69 Daily Chemical Loads at Bethel Early indications Have not yet accounted for true zero outflow conditions TP in treatment Inflow loads are statistically lower TP in control No statistical differences TS in either No statistical differences

70 Q&A

71 Webcast Resources Technical Memo: Performance Enhancing Devices for Stormwater Best Management Practices Internal Water Storage (IWS) for Bioretention - factsheet and design guidance from NCSU (2009)

72 Evaluation Please take a few moments to answer our 6 question survey to help us better serve your needs in our webcast series. We use this information to report it to assess our work, your needs and to report it to our funders for future webcasts!