Lockwood Folly Watershed Bacteria TMDL & LID

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1 Lockwood Folly Watershed Bacteria TMDL & LID

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3 FLOW RATE (CFS) HEWLETTS CREEK WATERSHED 1-YR STORM HYDROGRAPHS TIME (HRS)

4 Retrofit Challenges for Highways Performance (volume / efficiency) Cost Restricted to ROW Optimize Use of Space Ease of Maintenance

5 Bacteria TMDL Watershed Based Approach 1. Optimize the Use of LID for infiltration to reduce the annual load and to capture / deactivate bacteria in the landscape. 2. What load can t be infiltrated can be filtered. 3. Focus on highway retrofits. 4. Training 5. Pilot projects

6 Why Swales? 1. Collect and Concentrate 2. Habitat Value

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10 NCDOT LID Highway Treatment Techniques Permeable Friction Course (PFC) Bio-slope Dry Swale

11 PFC

12 Bio-Slope

13 Bio-Swale High Flow Rate Media 13

14 Filter swale

15 BIORETENTION ISSUES Original Design P.G County 1993 Design Standards Shallow Ponding - 6 Soil Depth % Sand 20% Sandy Loam 15% Compost Under Drain System Geotextiles Plants Allen Davis, University of Maryland Box Experiments Cumulative Depth (ft) Copper Lead Zinc Phosphorus TKN Ammonia Nitrate Removal Efficiency (%) Field

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17 Lessons Learned High Failure Rates Due to: Use of Old Design Standards - clay / organic / K factor Poor Drainage - Under drain design / Geo-fabrics / Saturated soils Media Variability - Reliable Sources Contractor Substitutes Contamination - P, N and Heavy Metals Sizing / Space Maintenance - Can be high as system become larger

18 Nationally Manufactured Regulatory Compliant Ease of Construction and Maintenance Consistent and Dependable Across the Country High Flow High Performance Bioretention Design

19 City of Portland, OR Low Flow - 1 to 3 / Hour Soaker Sand / Municipal Compost Ocean City, MD High Flow / Hour Filterra Corse Sand / Peat

20 High Pollutant Removal Rates All Third Party Studies To Date Total Phosphorus: 60% - 70% Total Nitrogen: 43% Total Suspended Solids: 85% Total Copper: > 58% Dissolved Copper: 46% Total Zinc: >66% Dissolved Zinc: 58% Oil & Grease: > 93%

21 Treatment Unit Processes Rate Description Particle Capturing Mechanisms Sedimentation Fast Particles settle on surface of media by gravity. Physical straining (filtering) Fast Larger particles cannot pass the media pores. Inertial Impaction Fast Particles adhere to filter media as they collide. Interception Fast Particles in close proximity attach to one another. adsorption Fast Accumulation of material onto filter media surface. absorption Incorporation of material into the filter media. Bacterial adsorption Fast Particles stick or adhere to bacteria cell wall slime. Plant adsorption Fast Particles adhere on plant roots. Chemical Biological Capturing Mechanisms Important in P, N and heavy metal removal Precipitation Fast Medium For example P may react with AL or Fe to form insoluble compounds. Cation & Anion Exchange Fast Compounds with exchangeable positive and negative ions are bond soil particles and organic material in the media Plant & Microbe ion exchange Fast medium Plant roots, mycelium hairs and microbe cell walls all have the ability to actively exchange ions with nutrients such as P, N and heavy metals Physical Adsorption Fast Electrostatic forces, electrokinetic forces and Vander Waals forces Volatilization Medium Volatile compounds are removed from the media through evaporation or actively removed through transpiration. Plant / Microbial Sequestration / transformation / growth Slow Mediated decay of organic material, uptake of nutrients and transformations of complex compounds for growth and energy.

22 Roots, Fungi & Bacteria Capturing Particle Bound Pollutants Bacteria dot the surface of strands of fungal hyphae. Credit: R. Campbell. Fibrous Roots Fungi Bacteria Particles are captured in first 2 to 8 inches in bioretention bed depths.

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24 Percent Removal (%) The Effect of Time on the Percent Fecal Coliform Removal by the Bacterra TM Media Blend (Field Findings) Initial Start Up = 4 storm events 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 2/11/2007 4/20/ /30/2007 1/6/2008 1/23/ % - 99% Removal 1/27/2008 2/3/2008 2/24/ /15/ /15/2008 1/23/2009 2/5/2009 2/5/2009 2/9/2009 2/13/2009 2/13/2009 2/16/ /14/ /7/ /7/2009 1/22/2010 2/5/2010 2/5/2010 Date

25 Removal Mechanisms Sorption 1 Filtration 1 Organic Matter 1 Biofilm 1 Temperature 1 ph 1 Flow Rate 1 Predators 2 CEC Slime on bacteria Many removal mechanisms Combination of all plays a big factor Ciliate Flagellate Amoeba 1 Rusciano and Obrupta research Rutgers University, NJ 2 Dr. Allen Davis 2007 LID Conference proceedings Photos: Nematode Rotifer

26 Helping Evolve LID 2 nd Generation Generic BioFiltration System Advancements: Higher Flow Media QA/QC & In-Situ Media Testing Plants Replace or Eliminate Geotextiles Mulch (when applicable) High-Flow Media High Performance Underdrain Include Detention Volume to Improve Infiltration Bridging Stone Packaged System Without Concrete FocalPoint Mesh Drive Down All Possible Costs High Performance Greater Volume Storage Underdrain Greater Flexibility

27 COMPARE BIOSWALES Typical High Flow (Focal Point System)

28 FocalPoint Roadway Design

29 Dollars and Sense Infiltration Rate Area Required Media Volume COST 2.5 / HR 1352 SF 81.5 CY $ 23, / HR 67 SF 4.3CY $ 6,700 Drainage Area 1 Acre,.95% impervious, 1 treated, 6 hour drawdown time.

30 Modular Flexibility Replaces low performance perforated pipe Adapts easily to utilities and unanticipated obstacles discovered in construction Adds design flexibility in layout and depth Provides options for infiltration, detention and storage for harvesting May expand beyond media bed

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33 Reduce Costs / Gallon Philadelphia Green Streets Program Standard Green Infrastructure 2 nd Generation Green Infrastructure Media Mesh Underdrain EXAMPLE: Standard Green Infrastructure 5 x 5 Tree Pit Treats 78 gallons/hour Cost = $10,000 Cost / Gallon = $128 2 nd Generation Green Infrastructure 5 x 5 FocalPoint Tree Pit Treats 1,558 gallons/hour Cost = $20,000 Cost / Gallon = $12. 80

34 High Performance Solution Enables smaller scale BMPs Increase uses and applications Increases usable land Minimizes non-routine maintenance regimes Treats as much water as we choose Flexible, modular design Simple, minimal maintenance routine Well developed QA and QC process Raises the bar for storm water systems