Promoting Green Technologies. Sameer Dhalla, P.Eng. Derek Smith, M.Sc., B.A. ARC Webinar October TRCA Jurisdiction

Transcription

1 Promoting Green Technologies Sameer Dhalla, P.Eng. Derek Smith, M.Sc., B.A. ARC Webinar October 2008 TRCA Jurisdiction The TRCA's area of jurisdiction includes: 3,467 sq. km: 2,506 on land and 961 water-based. This area is comprised of nine watersheds including: Etobicoke Creek Mimico Creek Humber River Don River Highland Creek Rouge River Petticoat Creek Duffins Creek Carruthers Creek The TRCA s jurisdiction also extends into Lake Ontario to a point defined by the Territorial Divisions Act, R.S.O The population in 2004 within TRCA s jurisdiction is approximately 4,300,000 (37% of Ontario s population). 1

2 Objectives Prepare a state-of-the-art guideline which would assist practitioners (consultants, developers) e and review e agencies es (TRCA, municipalities) in the planning, selection, ect design, maintenance and costing of a wide range of sustainable stormwater management practices Develop a consistent approach to water management which should lead to a more streamlined and focused design and review process Ensure that the goals, objectives and targets as outlined in larger scale studies (watershed and subwatershed studies) are being met Improve watershed health, promote a more resilient stromwater system and adapt to the effects of a changing climate (in southern Ontario, climate change is expected to result in more intense, less frequent rainfall events) Introduction History of stormwater management and why stormwater t is a problem Existing legislation and Agency's role Reinforce key themes Comprehensive studies upfront Integrated approach planners, ecologists, landscape, engineers Open mind to new approaches field is evolving 2

3 Source: Understanding Stormwater Management: An Introduction to Stormwater Management Planning and Design, MOE 2003 Concerns Stormwater is the primary source of pollution in the Don. That is not surprising, since Stormwater enters the Don and its tributaries through a total of 1,185 outfalls, and makes up 71% of the river s total flow. Stormwater carries everything that washes off the streets, expressways, shopping plazas, driveways, golf courses.. (Forty Steps to a New Don, 1994) Pollution - Water Quality Control Increased Peak Flows Flood Control Reduced Infiltration & Baseflow Water Balance Increased Erosion Water Balance / Flow Control 3

4 Water Quality 4

5 Location: Rouge Watershed Water Quality 5

6 Flooding (Aug. 19/05) Location: Highland Creek at Ellesmere and Birkdale Road Flooding (Aug. 19/05) Location: Black Creek at Highway 7 6

7 Streambank Erosion Affects water quality, aquatic habitats, infrastructure Streams are still responding to current levels of urban development Research from current watershed plans suggests current SWM approaches are not adequate Erosion 7

8 Risk to Infrastructure Location: Black Creek at Finch Avenue Note Complete Failure of Embankment and Roadway (Aug. 19/05) Stormwater Management Design Criteria Water Quality Provide an Enhanced Level of Treatment - 80% TSS Removal (The MOE Stormwater Management Planning and Design Manual will be used) Flood Flow Provide Stormwater Quantity Control (i.e. maintain postdevelopment peak flows to pre-development levels for 2 to 100-year return period design storm event. Erosion Control Complete an Erosion analysis and ensure erosion control targets are achieved (i.e. minimum 25 mm 24 hour detention) Water Balance Complete a Water Balance analysis and ensure water balance targets are achieved (i.e. pre development infiltration is maintained under post development conditions) 8

9 Flood Flow Criteria Criteria throughout TRCA jurisdiction has been established Flow criteria map illustrating the types of control required, unit flow rates and flow targets at key locations to be provided Erosion Control Overview as to the type of approaches required to develop erosion control criteria Simplified vs. Detailed Approach Standard Approach 9

10 Water Balance Define what is meant by water balance Water balance targets on a watershed basis to be provided as framework Approach for defining infiltration capacity to be defined 10

11 Stormwater Management Practices Stormwater criteria is achieved through the implementation of a Treatment Train of Stormwater Best Management Practices (BMPs) consisting of: Source Controls Conveyance Controls End-of-Pipe Controls Porous Pavers CWC / Infiltration Systems Wet Pond Low Impact Development SWM Practices Green Technologies (LID/Source Control Practices): Bioretention (STEP Monitoring) Permeable Pavers & Porous Pavement (STEP Monitoring) Rainwater Harvesting (STEP Monitoring) Green Rooftops (STEP Monitoring) Grass Swales Filter Strip/Snow Treatment Areas Rooftop Disconnection (with soil amendments) Dry Swales Soakaway Pits 11

12 SWM Practices Details will include: Description Common Concerns Physical Stability and Constraints Design Guidance Design Specification Typical Details Construction Inspection Typical Performance Maintenance Installation and Maintenance costs Construction Checklist 12

13 Maintenance Checklist Sustainable Technologies Evaluation Program 13

14 Sustainable Technologies Evaluation Program Multi-agency program led by TRCA Main program objectives: Evaluate clean water and air technologies Develop strategies to overcome implementation barriers Develop tools, guidelines and policies Education, advocacy, and technology transfer Program web address: 14

15 York University, Keele Campus Study Purpose Evaluate technology effectiveness with respect to: Water quality and quantity Watershed scale SWM benefits Potential on urban biodiversity Economic feasibility 15

16 Conclusions: SWM and Biodiversity Garden retained 63% of runoff (excl. winter), 54% with winter data. Performance was dependant on rainfall intensity and soil moisture. Pollutant loads of most contaminants of concern were lower, including: most nutrients, metals, and all PAHs. Initial phosphorus leaching was common among the 11 products tested. Native plants increased from 18 to 29 over two years. Greenroof could be conducive to the establishment of other plants. A total of six bird species were observed using the greenroof, two of which were breeding on site. 16

17 Greensborough Developments, Markham Study Purpose Evaluate technology gy effectiveness with respect to: Water quality and quantity Sediment accumulation rate in pond Receiving water impacts M d l h d d i Model hydrodynamics Update ESC guidelines 17

18 Conclusions Most sediment was trapped in forebay and after berm. pp y 99% removal efficiency (load basis), however, effluent was rarely below 25mg/L. Average was 55mg/L (13 to 95mg/L). No impact on receiving water (with dilution); moderate impact with no dilution. 18

19 Conclusions Conclusions 19

20 Seneca College, King Campus Study Purpose Evaluate technology effectiveness with respect to: Water quality and quantity Infiltration rates Soil quality Ground temperature Structural stability Maintenance issues Develop guidelines 20

21 Study Design: Plan View 21

22 Interim Study Results Results: 31mm Rainfall Depth (mm Flow (L L/s) m) Top of Permeable Pavement Top of Bioswale Conventional Asphalt Permeable Pavement Infiltrate Bioswale Infiltrate 15-Nov 16-Nov 17-Nov 18-Nov 19-Nov 5 Rainfall (mm m/hr)

23 Results: Water Quantity Permeable pavement infiltrated runoff from events up to approximately 50 mm. Bioswale infiltrated all runoff for events up to approx 20 to 25 mm. Water Quality Both infiltration i practices were effective in removing most contaminants typically found in parking lot runoff, with some exceptions, such as chloride. Frequency (%) Results: Winter Base Course Air to to -8-7 to 1 2 to to to 28 Temperature Range ( C) 23

24 Results: Survey of Other Installations Belfountain Conservation Area (1992) Earth Rangers Kortright Conservation Area (2003) Hong Kong Funeral Home (1996) Guelph University (1994) Humberwood Centre (1995) Sunset Beach Lake Wilcox (1999) 24

25 Results: Other Installations Generally ygood structural condition 3 sites showed moderate surface infiltration; remainder were poor. Poor infiltration attributed to fine sediment build-up within the void spaces. All sites indicated some signs of clogging (poor maintenance practices!) Results: Other Installations 25

26 Results: Technology Transfer Approx. 45 site tours Several formal presentations at workshops, seminars and conferences 3 interim reports; 2 conference papers and articles written by 3 rd parties. Annual fact sheets and web postings Dozens of external web references to the project Used extensively in the development review process Results: on the ground Large increase in permeable pavement specified in development submissions. e.g. 208 permeable driveways planned for a new subdivision in Richmond Hill and several commercial sites. Increased interest and acceptance of the technology among municipalities. Starting ti to receive endorsement by major consultants t and developers. Nevertheless, misconceptions remain strong 26

27 Future Work: Phase 2 Future Work: Phase 2 Objectives to evaluate the performance of open and dense graded base- courses; to assess water quality variables in permeable pavements installed with and without under drains; and to observe the effectiveness of clay soils to infiltrate runoff for various sized storms. 27

28 ESC Block 39 Demonstration Project, Vaughan Study Purpose Evaluate guideline g effectiveness with respect to: Water quality and quantity In-steam geomorphology and biodiversity Construction activities and landuse Water temperature Evaluate new enforcement tool 28

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30 Rainwater Harvesting System Metro Label, Scarborough; Minto Condominium, Toronto; Brookside Public School, Markham Study Purpose Evaluate technology gy effectiveness with respect to: Water quality and quantity Winter performance Maintenance issues Maintenance issues Watershed scalability Economic feasibility 30

31 Metro Label 31

32 Metro label: Interim Results Minto Condo, 150 Roehampton: Starting Spring

33 Brookside Public School: Starting Spring 2008 Sustainable House, Kortright CA, Vaughan 33

34 Sustainable House: Starting Summer 2008 Future STEP Projects Project Location Start Date Commercial parking lot infiltration system Brampton/Richmond Hill 2009 Commercial big-box roof runoff infiltration system Richmond Hill 2009 Pond outlet infiltration system Markham 2010 Hydrologic benefits of permeable driveways (subwatershed scale) Richmond Hill 2009 Residential/Institutional lot level infiltration practices Markham, Box Grove 2009 Chloride transport dynamics in infiltrations BMPs Kortright CA, Vaughan

35 Contact Information Derek Smith, BSc, MSc Phone: x dsmith@trca.on.ca STEP website: TRCA website: THANK YOU Questions? 35