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Inspection and Maintenance: Green Roofs (view source)
Revision as of 12:21, 8 August 2022
, 2 years agoCreated page with "thumb|750px|link=https://sustainabletechnologies.ca/app/uploads/2018/02/Green-Roofs-Fact-Sheet.pdf|Inspection & Maintenance Guidance of [[Green roofs best management practices. These specialized roofs are specially engineered and designed to support the growth of vegetation while protecting the structural integrity of the roof, aiding in helping to cool the building and effectively infiltrate, absorb and retain precipitation (TRCA, 201..."
[[File:Green roofs cover page.PNG|thumb|750px|link=https://sustainabletechnologies.ca/app/uploads/2018/02/Green-Roofs-Fact-Sheet.pdf|Inspection & Maintenance Guidance of [[Green roofs]] best management practices. These specialized roofs are specially engineered and designed to support the growth of vegetation while protecting the structural integrity of the roof, aiding in helping to cool the building and effectively infiltrate, absorb and retain precipitation (TRCA, 2018).<ref name="example1"> TRCA. 2018. Fact Sheet - Inspection and Maintenance of Stormwater Best Management Practices: Green Roofs. https://sustainabletechnologies.ca/app/uploads/2018/02/Green-Roofs-Fact-Sheet.pdf</ref>]]
{{TOClimit|2}}
==Overview==
Underground infiltration systems is a general term that refers to best management practices (BMPs) that capture and temporarily store stormwater from hard surfaces. These systems treat stormwater by detaining it to allow suspended sediments to settle out and soaking it into the ground where it is filtered and cleansed by interaction with [[Soil groups|soil]]. Runoff water is delivered to the practice through [[pipes]] connected to catchbasins, hydrodynamic (i.e., [[ Oil and grit separators|oil and grit]]) separators, filters, manholes, [[underdrains|sub-drains]] of other features or roof downspouts. They are installed below the local maximum frost penetration depth to ensure they continue to drain year-round. Water that is in excess of the storage capacity overflows to an adjacent drainage system (e.g., municipal storm sewer or other BMP), typically via pipe or manhole containing a [[Flow through riser|control structure]] (e.g., weir wall), to safely convey flows during flood events. Depending on the permeability of the underlying soil, such practices may be designed without a sub-drain for full infiltration or with a sub-drain for partial infiltration. The sub-drain pipe may feature a flow restrictor (e.g., orifice cap, valve) for gradually releasing detained water and optimizing the amount drained by infiltration. <br>
</br>
[[File:Plan & profile view Infilt underground.PNG|thumb|400px|General plan and profile (cross-section) views showcasing key components and sections of a typical [[infiltration trench]].]]
{{textbox|Key components of Underground Infiltration Systems to pay close attention to are the:
*[[Inlets]]
*[[Underdrains|Sub-Drains]]
*[[Wells|Monitoring Wells]]
*[[Overflow|Overflow outlets]]}}
Trash, debris and sediment builds up at these locations and can prevent water from flowing into or out of the practice.
==Associated Practices==
*'''[[Soakaways]]''': Typically service individual lots and receive only roof and walkway runoff but can also be designed to receive overflows from other BMPs (e.g., [[rainwater harvesting|rain barrels]] or [[Rainwater harvesting|cisterns]], [[rain gardens]], [[green roofs]]. Also known as infiltration galleries, French drains, [[Dry well|dry wells]] or soakaway pits.
*'''[[Infiltration trenches]]''': Linear oriented soakaways designed to fit into narrow strips of land between structures or properties, or along road rights-of-way; can also receive road runoff with adequate pretreatment devices upstream of inlets.
*'''[[Infiltration chambers]]''': Include a range of proprietary modular structures installed underground that create large void spaces for temporary storage of stormwater while providing sufficient load bearing capacity to allow construction of structures on top of them. Applications are similar to infiltration trenches. Also known as [[Infiltration chambers: Specifications|infiltration tanks or vaults]].
*'''[[Exfiltration trenches|Perforated pipe storm sewer systems]] or [[Exfiltration trenches]]''': Linear-oriented [[infiltration trenches]] installed parallel with conventional storm sewer pipes and catchbasins that receive stormwater from them. May include manholes with [[Flow through riser|perforated risers]]. Also known as exfiltration storm sewer, percolation drainage, or clean water collector systems.
==Inspection and Testing Framework==
[[File:Infiltration before cleanout infiltr.PNG|thumb|340px|An inlet to an infiltration trench during the fall in need of maintenance (TRCA, 2018).<ref name="example1" />]]
{| class="wikitable" style="width: 900px;"
|+'''Visual Indicators Framework - Underground Infiltration Systems'''
|-
!<br>'''Component'''
!<br>'''Indicators'''
!<br>'''Construction Inspection'''
!<br>'''Assumption Inspection'''
!<br>'''Routine Operation Inspection'''
!<br>'''Verification Inspection'''
|-
|rowspan="2"|'''[[Infiltration: Sizing and modeling|Contributing Drainage Area]]'''
|-
|CDA condition
|x
|x
|x
|x
|-
|rowspan="3"|'''[[Inlets|Inlet]]'''
|-
|Inlet/Flow Spreader Structural Integrity
|
|x
|x
|x
|-
|Inlet/Flow Spreader Structural Integrity
|x
|x
|x
|x
|-
|rowspan="2"|'''Perimeter'''
|-
|BMP dimensions
|x
|x
|
|x
|-
|rowspan="2"|'''[[Construction|Filter Bed]]'''
|-
|Filter bed sediment accumulation
|
|x
|x
|x
|-
|rowspan="3"|'''[[Underdrain]] & [[Wells|Monitoring Well]]'''
|-
|Monitoring well condition
|x
|x
|x
|x
|-
|Sub-drain/Perforated pipe obstruction
|
|x
|
|x
|-
|rowspan="2"|'''[[Overflow|Outlets]]'''
|-
|Overflow outlet obstruction
|x
|x
|x
|x
|-
|rowspan="3"|'''[[Flow through riser|Control Structure]]'''
|-
|Control structure condition
|x
|x
|x
|x
|-
|Control structure sediment accumulation
|x
|x
|x
|x
|-
|}<br>
</br>
[[File:Soakaway monitorign well.PNG|thumb|300px|An example of a soakaway under construction with a newly installed monitoring well. To ensure performance assessment and infiltration testing can be conducted efficiently over the life cycle of this LID feature, the well condition must stay in good condition and be repaired immediately upon notice of significant damage (TRCA, 2018)<ref name="example1" />.]]
{| class="wikitable" style="width: 900px;"
|+'''Testing Indicators Framework - Underground Infiltration Systems'''
|-
!<br>'''Component'''
!<br>'''Indicators'''
!<br>'''Construction Inspection'''
!<br>'''Assumption Inspection'''
!<br>'''Routine Operation Inspection'''
!<br>'''Verification Inspection'''
|-
|rowspan="4"|'''Testing Indicators'''
|-
|Sediment accumulation testing
|x
|x
|x
|x
|-
|Natural or simulated storm event testing
|
|x
|
|(x)
|-
|Continuous monitoring
|
|x
|
|(x)
|-
|colspan="7" style="text-align: center;" |'''<u><span title=>Note:''' (x) denotes indicators to be used for Performance Verification inspections only (i.e., not for Maintenance Verification inspections) </span></u>
|-
|}
{{TOClimit|2}}
==Overview==
Underground infiltration systems is a general term that refers to best management practices (BMPs) that capture and temporarily store stormwater from hard surfaces. These systems treat stormwater by detaining it to allow suspended sediments to settle out and soaking it into the ground where it is filtered and cleansed by interaction with [[Soil groups|soil]]. Runoff water is delivered to the practice through [[pipes]] connected to catchbasins, hydrodynamic (i.e., [[ Oil and grit separators|oil and grit]]) separators, filters, manholes, [[underdrains|sub-drains]] of other features or roof downspouts. They are installed below the local maximum frost penetration depth to ensure they continue to drain year-round. Water that is in excess of the storage capacity overflows to an adjacent drainage system (e.g., municipal storm sewer or other BMP), typically via pipe or manhole containing a [[Flow through riser|control structure]] (e.g., weir wall), to safely convey flows during flood events. Depending on the permeability of the underlying soil, such practices may be designed without a sub-drain for full infiltration or with a sub-drain for partial infiltration. The sub-drain pipe may feature a flow restrictor (e.g., orifice cap, valve) for gradually releasing detained water and optimizing the amount drained by infiltration. <br>
</br>
[[File:Plan & profile view Infilt underground.PNG|thumb|400px|General plan and profile (cross-section) views showcasing key components and sections of a typical [[infiltration trench]].]]
{{textbox|Key components of Underground Infiltration Systems to pay close attention to are the:
*[[Inlets]]
*[[Underdrains|Sub-Drains]]
*[[Wells|Monitoring Wells]]
*[[Overflow|Overflow outlets]]}}
Trash, debris and sediment builds up at these locations and can prevent water from flowing into or out of the practice.
==Associated Practices==
*'''[[Soakaways]]''': Typically service individual lots and receive only roof and walkway runoff but can also be designed to receive overflows from other BMPs (e.g., [[rainwater harvesting|rain barrels]] or [[Rainwater harvesting|cisterns]], [[rain gardens]], [[green roofs]]. Also known as infiltration galleries, French drains, [[Dry well|dry wells]] or soakaway pits.
*'''[[Infiltration trenches]]''': Linear oriented soakaways designed to fit into narrow strips of land between structures or properties, or along road rights-of-way; can also receive road runoff with adequate pretreatment devices upstream of inlets.
*'''[[Infiltration chambers]]''': Include a range of proprietary modular structures installed underground that create large void spaces for temporary storage of stormwater while providing sufficient load bearing capacity to allow construction of structures on top of them. Applications are similar to infiltration trenches. Also known as [[Infiltration chambers: Specifications|infiltration tanks or vaults]].
*'''[[Exfiltration trenches|Perforated pipe storm sewer systems]] or [[Exfiltration trenches]]''': Linear-oriented [[infiltration trenches]] installed parallel with conventional storm sewer pipes and catchbasins that receive stormwater from them. May include manholes with [[Flow through riser|perforated risers]]. Also known as exfiltration storm sewer, percolation drainage, or clean water collector systems.
==Inspection and Testing Framework==
[[File:Infiltration before cleanout infiltr.PNG|thumb|340px|An inlet to an infiltration trench during the fall in need of maintenance (TRCA, 2018).<ref name="example1" />]]
{| class="wikitable" style="width: 900px;"
|+'''Visual Indicators Framework - Underground Infiltration Systems'''
|-
!<br>'''Component'''
!<br>'''Indicators'''
!<br>'''Construction Inspection'''
!<br>'''Assumption Inspection'''
!<br>'''Routine Operation Inspection'''
!<br>'''Verification Inspection'''
|-
|rowspan="2"|'''[[Infiltration: Sizing and modeling|Contributing Drainage Area]]'''
|-
|CDA condition
|x
|x
|x
|x
|-
|rowspan="3"|'''[[Inlets|Inlet]]'''
|-
|Inlet/Flow Spreader Structural Integrity
|
|x
|x
|x
|-
|Inlet/Flow Spreader Structural Integrity
|x
|x
|x
|x
|-
|rowspan="2"|'''Perimeter'''
|-
|BMP dimensions
|x
|x
|
|x
|-
|rowspan="2"|'''[[Construction|Filter Bed]]'''
|-
|Filter bed sediment accumulation
|
|x
|x
|x
|-
|rowspan="3"|'''[[Underdrain]] & [[Wells|Monitoring Well]]'''
|-
|Monitoring well condition
|x
|x
|x
|x
|-
|Sub-drain/Perforated pipe obstruction
|
|x
|
|x
|-
|rowspan="2"|'''[[Overflow|Outlets]]'''
|-
|Overflow outlet obstruction
|x
|x
|x
|x
|-
|rowspan="3"|'''[[Flow through riser|Control Structure]]'''
|-
|Control structure condition
|x
|x
|x
|x
|-
|Control structure sediment accumulation
|x
|x
|x
|x
|-
|}<br>
</br>
[[File:Soakaway monitorign well.PNG|thumb|300px|An example of a soakaway under construction with a newly installed monitoring well. To ensure performance assessment and infiltration testing can be conducted efficiently over the life cycle of this LID feature, the well condition must stay in good condition and be repaired immediately upon notice of significant damage (TRCA, 2018)<ref name="example1" />.]]
{| class="wikitable" style="width: 900px;"
|+'''Testing Indicators Framework - Underground Infiltration Systems'''
|-
!<br>'''Component'''
!<br>'''Indicators'''
!<br>'''Construction Inspection'''
!<br>'''Assumption Inspection'''
!<br>'''Routine Operation Inspection'''
!<br>'''Verification Inspection'''
|-
|rowspan="4"|'''Testing Indicators'''
|-
|Sediment accumulation testing
|x
|x
|x
|x
|-
|Natural or simulated storm event testing
|
|x
|
|(x)
|-
|Continuous monitoring
|
|x
|
|(x)
|-
|colspan="7" style="text-align: center;" |'''<u><span title=>Note:''' (x) denotes indicators to be used for Performance Verification inspections only (i.e., not for Maintenance Verification inspections) </span></u>
|-
|}