Meadow Walk at Lynnfield
Meadow Walk at Lynnfield Design, Permitting and Implementation for Low Impact Development in 2008
June 23, 2008 EOEA Low Impact Development Conference for Developers
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Project Perspectives Developer – Ed Marsteiner - National Development Stormwater Consultant - Bethany Eisenberg, LEED AP – VHB Engineer - Danielle Spicer, P.E., LEED AP – Stantec
Developer Perspective - Ed Marsteiner National Development
Meadow Walk Design Process Permitting Process Technical Design/Stormwater Cost /Benefits
Meadow Walk History
• Purchased Colonial (Summer 2006)
Key Elements of Sustainable Design
High pedestrian access to multiple uses
114 Acres Open Space -Habitat/Wetland Protection
Sustainable Landscape Design -Water/Habitat
Stormwater Management dispersed throughout the site
I-95
Higher density development close to highway access
Land Conservation Buffer Zone Restoration Water Balance/Hydrology Mixed Uses Decrease Carbon Footprint Low Impact Development (LID) Practices
Permitting Hurdles
Natural Heritage Mass Audubon Local Conservation Commission – 2 towns DEP Stormwater MEPA MWRA Saugus River Watershed Council Lynn Water Sewer Commission
Key Resources to Protect
Wildlife Wetland Open Space Water
Consistent Thread for All Reviewers Low Impact Development Stormwater Management Land Preservation – Resource Buffers LEED – Water Use Reduction Transportation Management Program
Benefits
Tenant Perspective Permitting efficiency Peace of mind of design Complex system – not typical
Additional Soft Costs – New Stormwater Regs ~$310,000 in Additional Testing & Consultant Review Geotechnical Additional test pits, borings & probes Mounding analysis & groundwater modeling Design Engineer (Stantec) – Design Adjustments (Calcs & Plans) Internal Technical Review (VHB) Additional Peer Review Time/Money Time – Timing of Filing & Complexity of New Regs Added 1-2 months to permitting time frame (carrying costs)
Hard Costs – Subsurface Storage $13-$15 PSF 24” – 48” HDPE Corrugated Pipe Manholes Gravel
Does not include excavation ($3 to $4 per yard assuming material used on site) Quantity of over 100,000sf
Hard Costs – Porous Pavement $85/sy
30+” Stratified sub-base Filter fabric Piping (Overflow Drain) Asphalt
Does not include excavation and removal of existing material (if necessary) - $10/cy
Hard Costs – Porous Pavement Intangibles Elimination or Downsizing of Traditional Stormwater Components Basins Grading, liners, fencing, slope stabilization, structures, etc. Space Elimination or downsizing of stormwater basins may allow more program or a more efficient site layout Aesthetics More attractive than basins
Hard Costs – Vegetated Swales $95/sy
Amended soil ($50/cy) Wood guard rail ($30/lf) Check Dams Overflow CB
Does not include landscaping which can vary greatly (Trees, shrubs, plugs, wetland seed mix, etc.) – We budget $45/sy
Hard Costs – Stormceptors Buy stock in Stormceptor 15 on Meadow Walk project alone O&M costs TBD
Stormwater Management/LID – Bethany Eisenberg
•LID BMP Selection •Site specific info needed •Significant field investigations •Developing new details •Modifying for new MA Standards
LID Selection Focus on Existing Water/Wetland Resources to Protect Key existing resources were identified and drove the proposed design: Lynn Water Supply Lynn water supply: reedy meadow, canal, No Outstanding Resource Waters (ORWs)Wetlands Natural Heritage/MA Audubon Reedy Meadow Water Balance Saugus River Water Balance (follow this slide with graphic that has fly ins of each of these things)
LID Practices – Protection of Wetlands with Land Conservation
Principle Concept for LID
LID – Protection of Resources with Buffers, Set backs and Wetland Edge Restoration
Need Better Slide from Stantec and discussion points
Site Hydrogeology Drove LID Selection for the Development Area • • • • • • •
64 Test Pits 25 Monitoring Wells 14 Percolation Tests 9 Falling Head Permeability 10 Rising Head Permeability 15 Grain Size analysis Mounding analyses
LID selection for a Bedrock Hill with Sands at the Wetland Edge
LID Practices – Bioretention Swales for Water Quality Treatment in High Traffic Areas
Bioretention Swales in Parking Areas High water quality treatment before infiltration or detention Overflow to subsurface detention or surface detention Under drains required due to subsurface conditions Double shredded hardwood mulch 2 ft. min bioretention media 6-9 inch ponding depth Can be landscaped to match desired look of the development
23
LID Practices – Dispersed Infiltration, Detention
Water Balance
•Consistent with National (i.e. LEED) and MADEP Standards for LID
LID Practices – Porous Pavement in Sand at the Wetland Edge •Higher Permeability •Less vehicular trips •Permanent residential area with more control of use and O&M
LID Practices – Extensive Landscaping
Low Impact /Sustainable Landscaping
Native Species Draught tolerant Species Integrated Pest Management Shade Trees
27
LID Benefits of Planting Trees One mature tree can increase a property value by 15% Trees around a home can reduce summer cooling costs by 30% Winter heating costs can be reduced using trees as windbreaks (30% ±) Pollutant removal (carbon, nitrous dioxide, sulfur dioxide)
1 tree removes 13 1lbs ± carbon per year
Puget Sound:
Estimated 78M lbs. of pollutants removed per year
Cost $19.5M if removed by industrial treatment process
Integration of Trees
Image by GreenbergFarrow
Integration of Trees
Image by GreenbergFarrow
Screening
Image by GreenbergFarrow
Screening
Image by GreenbergFarrow
Full Build Project - focused on resource protection
Engineer’s Perspective – Danielle Spicer - Stantec Questions the design engineer must now face… How to meet the new MA Stormwater Handbook regulations? Design a sustainable site? Keep the project on budget? Keep the client happy?
Engineer’s Perspective The New MA Stormwater Handbook Regulations The new regulations are requiring more detailed engineering and more existing site specific information. This can result in a lengthier time to finalize the design which results in higher costs to the client.
Meadow Walk – 200 acres
Extensive Geotechnical Investigations • • • • • • •
64 Test Pits 25 Monitoring Wells 14 Percolation Tests 9 Falling Head Permeability 10 Rising Head Permeability 15 Grain Size analysis Mounding analyses
That’s 137 tests!
Engineer’s Perspective 13 Proposed Stormwater Basins
Engineer’s Perspective There are three substantial changes in the new regulations that require more engineering. Recharge Water Quality Land Uses with High Potential Pollutant Loads (LUHPPL)
Engineer’s Perspective Recharge Higher Recharge Volumes Hydrologic Group
Old Recharge Depth x Total Impervious Area
New Recharge Depth x Total Impervious Area
A
0.40 inches
0.60 inches
B
0.25 inches
0.35 inches
C
0.10 inches
0.25 inches
D
waived
0.10 inches
Engineer’s Perspective Recharge - Additional treatment required before recharging At least 44% of the TSS MUST be removed prior to discharge to an Infiltration structure if:
Within a Zone II or Interim Wellhead Protection Area Near a Critical Area From Land Uses with higher Potential Pollutant Loads (LUHPPL) In an Area with Rapid Infiltration Rate (>2.4 inches/hour)
At least 80% of the TSS MUST be removed prior to discharge to an Infiltration structure if:
Using the Dynamic Field Method
Engineer’s Perspective Water Quality The TSS removal efficiencies have all been updated There are more requirements that need to be met in order to use a Proprietary Separators. Proprietary Separators now have an individual TSS removal efficiency based on the manufacturer (see UMass Amherst website) Need to show not only 80% removal at end of treatment train, but may need to show pretreatment TSS removal rates.
Engineer’s Perspective Water Quality Treatment Train with 44% TSS pretreatment removal shown
Engineer’s Perspective Land Uses with Higher Potential Pollutant Load (LUHPPL)
Recharge from a LUHPPL is now required in Zone II Drinking Water Areas Specific Pretreatment for LUHPPL required (44% TSS removal prior to discharge to an infiltration basin) More water quality treatment required – 1” rule Updated list of BMPs that are appropriate for LUHPPL based on latest science
Engineer’s Perspective Conclusion The overall goal is to provide better environmental protection for future developments
Engineer’s Perspective
June 23, 2008 EOEA Low Impact Development Conference for Developers
P
Project Perspectives Developer – Ed Marsteiner - National Development Stormwater Consultant - Bethany Eisenberg, LEED AP – VHB Engineer - Danielle Spicer, P.E., LEED AP – Stantec
Developer Perspective - Ed Marsteiner National Development
Meadow Walk Design Process Permitting Process Technical Design/Stormwater Cost /Benefits
Meadow Walk History
• Purchased Colonial (Summer 2006)
Key Elements of Sustainable Design
High pedestrian access to multiple uses
114 Acres Open Space -Habitat/Wetland Protection
Sustainable Landscape Design -Water/Habitat
Stormwater Management dispersed throughout the site
I-95
Higher density development close to highway access
Land Conservation Buffer Zone Restoration Water Balance/Hydrology Mixed Uses Decrease Carbon Footprint Low Impact Development (LID) Practices
Permitting Hurdles
Natural Heritage Mass Audubon Local Conservation Commission – 2 towns DEP Stormwater MEPA MWRA Saugus River Watershed Council Lynn Water Sewer Commission
Key Resources to Protect
Wildlife Wetland Open Space Water
Consistent Thread for All Reviewers Low Impact Development Stormwater Management Land Preservation – Resource Buffers LEED – Water Use Reduction Transportation Management Program
Benefits
Tenant Perspective Permitting efficiency Peace of mind of design Complex system – not typical
Additional Soft Costs – New Stormwater Regs ~$310,000 in Additional Testing & Consultant Review Geotechnical Additional test pits, borings & probes Mounding analysis & groundwater modeling Design Engineer (Stantec) – Design Adjustments (Calcs & Plans) Internal Technical Review (VHB) Additional Peer Review Time/Money Time – Timing of Filing & Complexity of New Regs Added 1-2 months to permitting time frame (carrying costs)
Hard Costs – Subsurface Storage $13-$15 PSF 24” – 48” HDPE Corrugated Pipe Manholes Gravel
Does not include excavation ($3 to $4 per yard assuming material used on site) Quantity of over 100,000sf
Hard Costs – Porous Pavement $85/sy
30+” Stratified sub-base Filter fabric Piping (Overflow Drain) Asphalt
Does not include excavation and removal of existing material (if necessary) - $10/cy
Hard Costs – Porous Pavement Intangibles Elimination or Downsizing of Traditional Stormwater Components Basins Grading, liners, fencing, slope stabilization, structures, etc. Space Elimination or downsizing of stormwater basins may allow more program or a more efficient site layout Aesthetics More attractive than basins
Hard Costs – Vegetated Swales $95/sy
Amended soil ($50/cy) Wood guard rail ($30/lf) Check Dams Overflow CB
Does not include landscaping which can vary greatly (Trees, shrubs, plugs, wetland seed mix, etc.) – We budget $45/sy
Hard Costs – Stormceptors Buy stock in Stormceptor 15 on Meadow Walk project alone O&M costs TBD
Stormwater Management/LID – Bethany Eisenberg
•LID BMP Selection •Site specific info needed •Significant field investigations •Developing new details •Modifying for new MA Standards
LID Selection Focus on Existing Water/Wetland Resources to Protect Key existing resources were identified and drove the proposed design: Lynn Water Supply Lynn water supply: reedy meadow, canal, No Outstanding Resource Waters (ORWs)Wetlands Natural Heritage/MA Audubon Reedy Meadow Water Balance Saugus River Water Balance (follow this slide with graphic that has fly ins of each of these things)
LID Practices – Protection of Wetlands with Land Conservation
Principle Concept for LID
LID – Protection of Resources with Buffers, Set backs and Wetland Edge Restoration
Need Better Slide from Stantec and discussion points
Site Hydrogeology Drove LID Selection for the Development Area • • • • • • •
64 Test Pits 25 Monitoring Wells 14 Percolation Tests 9 Falling Head Permeability 10 Rising Head Permeability 15 Grain Size analysis Mounding analyses
LID selection for a Bedrock Hill with Sands at the Wetland Edge
LID Practices – Bioretention Swales for Water Quality Treatment in High Traffic Areas
Bioretention Swales in Parking Areas High water quality treatment before infiltration or detention Overflow to subsurface detention or surface detention Under drains required due to subsurface conditions Double shredded hardwood mulch 2 ft. min bioretention media 6-9 inch ponding depth Can be landscaped to match desired look of the development
23
LID Practices – Dispersed Infiltration, Detention
Water Balance
•Consistent with National (i.e. LEED) and MADEP Standards for LID
LID Practices – Porous Pavement in Sand at the Wetland Edge •Higher Permeability •Less vehicular trips •Permanent residential area with more control of use and O&M
LID Practices – Extensive Landscaping
Low Impact /Sustainable Landscaping
Native Species Draught tolerant Species Integrated Pest Management Shade Trees
27
LID Benefits of Planting Trees One mature tree can increase a property value by 15% Trees around a home can reduce summer cooling costs by 30% Winter heating costs can be reduced using trees as windbreaks (30% ±) Pollutant removal (carbon, nitrous dioxide, sulfur dioxide)
1 tree removes 13 1lbs ± carbon per year
Puget Sound:
Estimated 78M lbs. of pollutants removed per year
Cost $19.5M if removed by industrial treatment process
Integration of Trees
Image by GreenbergFarrow
Integration of Trees
Image by GreenbergFarrow
Screening
Image by GreenbergFarrow
Screening
Image by GreenbergFarrow
Full Build Project - focused on resource protection
Engineer’s Perspective – Danielle Spicer - Stantec Questions the design engineer must now face… How to meet the new MA Stormwater Handbook regulations? Design a sustainable site? Keep the project on budget? Keep the client happy?
Engineer’s Perspective The New MA Stormwater Handbook Regulations The new regulations are requiring more detailed engineering and more existing site specific information. This can result in a lengthier time to finalize the design which results in higher costs to the client.
Meadow Walk – 200 acres
Extensive Geotechnical Investigations • • • • • • •
64 Test Pits 25 Monitoring Wells 14 Percolation Tests 9 Falling Head Permeability 10 Rising Head Permeability 15 Grain Size analysis Mounding analyses
That’s 137 tests!
Engineer’s Perspective 13 Proposed Stormwater Basins
Engineer’s Perspective There are three substantial changes in the new regulations that require more engineering. Recharge Water Quality Land Uses with High Potential Pollutant Loads (LUHPPL)
Engineer’s Perspective Recharge Higher Recharge Volumes Hydrologic Group
Old Recharge Depth x Total Impervious Area
New Recharge Depth x Total Impervious Area
A
0.40 inches
0.60 inches
B
0.25 inches
0.35 inches
C
0.10 inches
0.25 inches
D
waived
0.10 inches
Engineer’s Perspective Recharge - Additional treatment required before recharging At least 44% of the TSS MUST be removed prior to discharge to an Infiltration structure if:
Within a Zone II or Interim Wellhead Protection Area Near a Critical Area From Land Uses with higher Potential Pollutant Loads (LUHPPL) In an Area with Rapid Infiltration Rate (>2.4 inches/hour)
At least 80% of the TSS MUST be removed prior to discharge to an Infiltration structure if:
Using the Dynamic Field Method
Engineer’s Perspective Water Quality The TSS removal efficiencies have all been updated There are more requirements that need to be met in order to use a Proprietary Separators. Proprietary Separators now have an individual TSS removal efficiency based on the manufacturer (see UMass Amherst website) Need to show not only 80% removal at end of treatment train, but may need to show pretreatment TSS removal rates.
Engineer’s Perspective Water Quality Treatment Train with 44% TSS pretreatment removal shown
Engineer’s Perspective Land Uses with Higher Potential Pollutant Load (LUHPPL)
Recharge from a LUHPPL is now required in Zone II Drinking Water Areas Specific Pretreatment for LUHPPL required (44% TSS removal prior to discharge to an infiltration basin) More water quality treatment required – 1” rule Updated list of BMPs that are appropriate for LUHPPL based on latest science
Engineer’s Perspective Conclusion The overall goal is to provide better environmental protection for future developments
Engineer’s Perspective
