Changes

#Use a plate compactor for smaller areas that the vibratory roller cannot reach.

#Use a plate compactor for smaller areas that the vibratory roller cannot reach.

==Chamber Installation==

==Trench, Chamber, and Perforated Pipe Installation==

The installation of infiltration chambers requires the placement of manifolds, the chamber components themselves, and perimeter stone. As such, the construction of infiltration chambers is a multi-faceted process.

The guidance provided in this section is applicable for the construction of soakaway pits, infiltration chambers, infiltration trenches, and exfiltration pipes of varying size and shape, since the installation of each of these features is similar.

[[File:Chamber-excavator.jpg|400px|thumb|right|An excavator covering units of unfinished infiltration chamber rows with perimeter stone. Stone can be applied progressively as the rows are completed to ensure that space is provided for the excavator to work within the LID footprint. Photo provided by [https://www.mswmag.com/g/product-focus/2015/08/stormwater_management_advanced_drainage_systems_stormtech_mc_4500 Municipal Sewer & Water].]]

[[File:Chamber-excavator.jpg|400px|thumb|right|An excavator covering units of unfinished infiltration chamber rows with perimeter stone. Stone can be applied progressively as the rows are completed to ensure that space is provided for the excavator to work within the LID footprint. Photo provided by [https://www.mswmag.com/g/product-focus/2015/08/stormwater_management_advanced_drainage_systems_stormtech_mc_4500 Municipal Sewer & Water].]]

'''Construction Steps:'''<ref>https://https://assets.ads-pipe.com/m/17aa795463b87e42/original/MC-3500-MC-4500-StormTech-Chamber-Installation-Guide.pdf </ref>

#Apply clear stone to the floor of the excavation to act as the base for chambers, pipes, and trenches.

#Install chamber manifolds to the top of the storage reservoir.

#For infiltration chamber construction, install chamber feeder-pipes to the top of the base, connecting to the inlet control manhole, where applicable.

#Roll out scour fabric length-wise along the manifold.

#Roll out scour fabric length-wise beside any feeder-pipes that have been installed, if specified in the design.

#Lay out scour fabric where the base of the infiltration chamber is anticipated to be installed. No seams should be present where the fabric underlies the chambers.

#If specified, lay out scour fabric where the base of the infiltration chamber, soakaway, or pipe is anticipated to be installed. No seams should be present where the fabric underlies chambers.

#Align the inlet to the first chamber row with the manifold.

#Install chambers, trenches, or perforated pipes at the location and elevation specified in the contract documents. Where infiltration chambers need to be assembled from units, install each piece of the chamber row, as per the manufacturer’s instructions, until the entire length of the chamber is in place. The ends of the chamber may be installed just prior to perimeter stone being applied to the ends of the rows, if desired, to ensure ease of inspection.

#Install each piece of the first chamber row, as per the manufacturer’s instructions, until the entire length of the chamber is in place. The ends of the chamber may be installed once perimeter stone is being applied to the ends of the rows, if desired, to ensure ease of inspection.

#Connect any perforated pipe connections, underdrains, roof leaders, or observation wells at the appropriate elevations, per the design.

#With a stone conveyor or excavator, begin placing perimeter stone. For domed chambers, place stone along the centreline of the chamber rows. Doing so will distribute stone to either side of the chamber, anchoring each side in roughly equal proportion.

#With a stone conveyor or excavator, begin placing clear stone as specified in the design. For domed chambers, place stone along the centreline of the chamber rows. Doing so will distribute stone to either side of the chamber, anchoring each side in roughly equal proportion.

#Backfill the excavated area with perimeter stone to the depth specified in the contract documents. Ensure that the depth of stone does not differ by more than 300 mm between the sides of the chamber rows at any point during the backfilling process.

#Backfill the excavated area with clear stone to the depth specified in the contract documents. Ensure that the depth of stone does not differ by more than 300 mm between the sides of any given chamber row at any point during the backfilling process.

#Once backfilling is complete, level the perimeter stone with a small dozer. Only push material in the direction parallel to the rows.

#Once backfilling is complete, level the perimeter stone with a small dozer. Only push material in the direction parallel to the rows.

#If specified by the design, roll geotextile parallel to rows over the top of stone. Provide sufficient overlap, as specified by the manufacturer. STEP does not recommend the use of geotextiles, however.

#If specified by the design, roll geotextile parallel to rows over the top of stone. Provide sufficient overlap, as specified by the manufacturer.

'''Note:''' where many rows of chambers are being installed, it may be advisable to construct the chamber rows piece-wise as the application of perimeter stone progresses to provide space for excavators to apply the stone from on top of the stone foundation. See the adjacent photo for an example.

Note: where many rows of infiltration chambers are being installed, it may be advisable to construct the chamber rows piece-wise as the application of perimeter stone progresses to provide space for excavators to apply the stone from on top of the stone base. See the adjacent photo for an example.

'''Key Inspection Points:'''

'''Key Inspection Points:'''

*Manifolds protrude into the storm chambers at the appropriate length, per manufacturer’s specifications.

*Feeder-pipes protrude into the storm chambers at the appropriate length, per manufacturer’s specifications.

*Scour fabric does not overlap beneath the walls of the chambers.

*Scour fabric does not overlap beneath the walls of open-bottom chambers.

*Minimum distance between adjacent chambers is provided.

*Minimum distance between adjacent chambers is provided.

*Minimum depth of stone below and stone above chamber is provided.

*Minimum depth of stone below and stone above chamber is provided, per manufacturer specifications.

*Depth of chamber inverts are installed correctly, relative to the elevation of the inlet, such that the storage potential of the chamber is maximized.

*Depth of chamber inverts are installed correctly, relative to the elevation of the inlet, such that the storage potential of chambers are maximized.

*Infiltration chambers are assembled as specified in the design.

*Infiltration chambers are assembled as specified by the manufacturer.

*Perimeter stone extends to the excavation walls.

*Perimeter stone extends to the excavation walls.

'''Mistakes to Avoid:'''

'''Mistakes to Avoid:'''

*Equipment on the perimeter stone – Perimeter stone should be applied with a stone conveyor or excavator from the outside of the LID footprint or on the stone foundation.

*Equipment on the perimeter stone – Perimeter stone should be applied with a stone conveyor or excavator from the outside of the LID footprint or on the stone foundation.

*Uneven perimeter stone – Perimeter stone must be applied such that the depth of stone on one side of the chamber is not unacceptably higher than the other. Refer to design details.  

*Uneven perimeter stone – Perimeter stone must be applied such that the depth of stone on one side of the chamber is not unacceptably higher than the other. Refer to design details.  

*Incorrect inlet elevation – For applications where infiltration chambers overflow into a sewer, it is important that the top of chamber is positioned at an elevation below the lowest invert of the sewer. Otherwise, only part of the chamber volume can be utilized.

*Incorrect inlet elevation – For applications where infiltration chambers overflow into a sewer, it is important that the top of chamber is positioned at an elevation below the lowest invert of the other sewer connections. Otherwise, only part of the chamber volume can be utilized.

*Putting system online prematurely -  Do not allow the feature to receive stormwater when contributing drainage area is not stabilized and sediment and debris is present.

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