Changes

[[File:Construction page lead photo.JPG|500px|thumb|right|CVC staff conducting a construction inspection at Kenollie Public School, Mississauga, Ontario. (Photo source: CVC)]]

[[File:Construction page lead photo.JPG|500px|thumb|right|CVC staff conducting a construction inspection at Kenollie Public School, Mississauga, Ontario. (Photo source: CVC, 2015)]]

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Published research corroborates STEP’s experiences in the field (e.g., (DelGrosso et al., 2019 <ref> Delgrosso, Z.L., Clayton, C.H., Dymond, R.L. 2019 Identifying Key Factors for Implementation and Maintenance of Green Stormwater Infrastruture. Journal of Sustainable Water in the Built Environment. 5 (3): 05019002. https://ascelibrary.org/doi/10.1061/JSWBAY.0000878</ref>); LSRCA, 2011<ref>Lake Simcoe Region Conservation Authority (LSRCA). 2011. Stormwater Pond Maintenance and Anoxic Conditions Investigation. Final Report. Newmarket, ON. https://sustainabletechnologies.ca/app/uploads/2015/01/LSRCA-Stormwater-Maintenance-and-Anoxic-Conditions-2011.pdf</ref>); ([https://www.chesapeakebay.net/channel_files/19219/cwp_james_river_tech_report_final_draft_062509.pdf.pdf CWP, 2009])<ref>Centre for Watershed Protection. 2009. Technical Report

Published research corroborates STEP’s experiences in the field (e.g., (DelGrosso et al., 2019 <ref> Delgrosso, Z.L., Clayton, C.H., Dymond, R.L. 2019 Identifying Key Factors for Implementation and Maintenance of Green Stormwater Infrastruture. Journal of Sustainable Water in the Built Environment. 5 (3): 05019002. https://ascelibrary.org/doi/10.1061/JSWBAY.0000878</ref>); LSRCA, 2011<ref>Lake Simcoe Region Conservation Authority (LSRCA). 2011. Stormwater Pond Maintenance and Anoxic Conditions Investigation. Final Report. Newmarket, ON. https://sustainabletechnologies.ca/app/uploads/2015/01/LSRCA-Stormwater-Maintenance-and-Anoxic-Conditions-2011.pdf</ref>); ([https://www.chesapeakebay.net/channel_files/19219/cwp_james_river_tech_report_final_draft_062509.pdf.pdf CWP, 2009])<ref>Centre for Watershed Protection. 2009. Technical Report

Stormwater BMPs in Virginia’s James River Basin: An Assessment of Field Conditions & Programs (part of the Extreme BMP Makeover project). Prepared by David Hirschman, Laurel Woodworth, and Sadie Drescher Center for Watershed Protection, Inc. Final Draft. June 2009. https://www.chesapeakebay.net/channel_files/19219/cwp_james_river_tech_report_final_draft_062509.pdf.pdf</ref>.; see the [[inspection and maintenance]] page’s overview for a more detailed discussion).  Del Grosso et al provide a helpful summary of positive considerations for LID construction: “[LID] requires more considerations during construction compared to traditional stormwater management facilities. …  The proper construction of [LID] is centered around thoughtful construction sequencing, ensuring all parties involved know their responsibilities, protecting soils and media from compaction and clogging, property installing filter media and aggregate, and ensuring facilities are kept off-line until the entire drainage area is stabilized. More generally, it is important for contractors to be aware of the sensitivity of GSI and for municipalities to ensure that facilities are being inspected by qualified inspectors at critical points (Del Grosso et al, 2019, pg. 8).

Stormwater BMPs in Virginia’s James River Basin: An Assessment of Field Conditions & Programs (part of the Extreme BMP Makeover project). Prepared by David Hirschman, Laurel Woodworth, and Sadie Drescher Center for Watershed Protection, Inc. Final Draft. June 2009. https://www.chesapeakebay.net/channel_files/19219/cwp_james_river_tech_report_final_draft_062509.pdf.pdf</ref>.; see the [[inspection and maintenance]] page’s overview for a more detailed discussion).  Del Grosso et al., 2019 provide a helpful summary of positive considerations for LID construction: “[LID] requires more considerations during construction compared to traditional stormwater management facilities. …  The proper construction of [LID] is centered around thoughtful construction sequencing, ensuring all parties involved know their responsibilities, protecting soils and media from compaction and clogging, property installing filter media and aggregate, and ensuring facilities are kept off-line until the entire drainage area is stabilized. More generally, it is important for contractors to be aware of the sensitivity of GSI and for municipalities to ensure that facilities are being inspected by qualified inspectors at critical points (Del Grosso et al., 2019, pg. 8).

Regular inspections throughout the construction process of LID practices prevent end products that are not built to the design specifications. Specifically, they ensure that:

Regular inspections throughout the construction process of LID practices prevent end products that are not built to the design specifications. Specifically, they ensure that:

For this reason, Stages 1-2 and 5 of the LID construction process are fundamentally similar for all sub-surface and ground-level LID types. To illustrate, STEP's recommended processes for excavation do not differ between LID practice types. Excavation procedures are the same, whether for a bioretention garden or a permeable pavement parking lot. On the other hand, stage 4 sub-tasks will vary depending on whether the LID practice's surface is vegetated or permeable pavement. Some sub-tasks in stage 3 will also vary depending on the LID type. For example, permeable pavements often require compaction of sub-surface storage layers. The following sections give a brief description of each over-arching stage, a list of sub-tasks for each stage, and links to the page dedicated to each main LID construction stage.

For this reason, Stages 1-2 and 5 of the LID construction process are fundamentally similar for all sub-surface and ground-level LID types. To illustrate, STEP's recommended processes for excavation do not differ between LID practice types. Excavation procedures are the same, whether for a bioretention garden or a permeable pavement parking lot. On the other hand, stage 4 sub-tasks will vary depending on whether the LID practice's surface is vegetated or permeable pavement. Some sub-tasks in stage 3 will also vary depending on the LID type. For example, permeable pavements often require compaction of sub-surface storage layers. The following sections give a brief description of each over-arching stage, a list of sub-tasks for each stage, and links to the page dedicated to each main LID construction stage.

[[Green roof|Green roofs]] and [[rainwater harvesting]] systems have specific construction sequences and requirements that differ from the main sequence described above. STEP has developed guidance for [[green roof construction]]; '''guidance on installing rainwater harvesting practices is forthcoming'''. When installing these BMP types, always consult the product manufacturer's guidance.

[[Green roof|Green roofs]] and [[rainwater harvesting]] systems have specific construction sequences and requirements that differ from the main sequence described above. STEP has developed guidance for [[green roof construction]]; '''guidance on installing rainwater harvesting practices is forthcoming'''. When installing these BMP types, always consult the product manufacturer's guidance.

==Excavation and grading==

==Excavation and grading==

[[File:Excavation belfountain swale.JPG|200px|thumb|right|Excavation of a rain garden at Belfountain Public School, Caledon, Ontario. (Photo source: CVC)]]

[[File:Excavation belfountain swale.JPG|400px|thumb|right|Excavation of a rain garden at Belfountain Public School, Caledon, Ontario. (Photo source: CVC, 2021)]]

   

   

Excavation and grading are necessary for installing LID practices with sub-surface components, re-grading land to hold more water, and re-routing overland flow routes into an LID practice. The [[Excavation and grading|excavation and grading]] page gives guidance on:  

Excavation and grading are necessary for installing LID practices with sub-surface components, re-grading land to hold more water, and re-routing overland flow routes into an LID practice. The [[Excavation and grading|excavation and grading]] page gives guidance on:  

==Finishing grades and surface layer installation==

==Finishing grades and surface layer installation==

[[File:Planting CVC Janet I McDougald.JPG|400px|thumb|right|CVC and Toronto Zoo staff planting the surface layer of a rain garden at Janet I McDougald Public School in Mississauga, Ontario. (Photo source: CVC)]]

[[File:Planting CVC Janet I McDougald.JPG|400px|thumb|right|CVC and Toronto Zoo staff planting the surface layer of a rain garden at Janet I McDougald Public School in Mississauga, Ontario. (Photo source: CVC, 2021)]]

This construction stage differs between LID practice type. The [[finishing grades and surface layer installation: vegetated LIDs]] page has guidance for vegetated LIDs, and the [[finishing grades and surface layer installation: permeable pavements]] page has guidance for and non-vegetated LIDs. In many cases the surface of infiltration systems will be traditional asphalt, concrete, or pavers; STEP does not provide guidance on installing non-permeable surfaces.   

This construction stage differs between LID practice type. The [[finishing grades and surface layer installation: vegetated LIDs]] page has guidance for vegetated LIDs, and the [[finishing grades and surface layer installation: permeable pavements]] page has guidance for and non-vegetated LIDs. In many cases the surface of infiltration systems will be traditional asphalt, concrete, or pavers; STEP does not provide guidance on installing non-permeable surfaces.   

*Addressing deficiencies

*Addressing deficiencies

*Final certification

*Final certification