Changes

At a minimum, continuous monitoring should be undertaken as part of Assumption and Verification inspections in the following situations:  

At a minimum, continuous monitoring should be undertaken as part of Assumption and Verification inspections in the following situations:  

 

#For infiltration BMPs designed without sub-drains to determine active sub-surface water storage reservoir volume drainage time and filter bed surface infiltration rate.

#For infiltration BMPs designed without sub-drains to determine active sub-surface water storage reservoir volume drainage time and filter bed surface infiltration rate.

#For infiltration BMPs designed with flow-restricted sub-drains, to determine sub-drain peak flow rate, active sub-surface water storage reservoir volume drainage time and filter bed surface infiltration rate.

#For infiltration BMPs designed with flow-restricted sub-drains, to determine sub-drain peak flow rate, active sub-surface water storage reservoir volume drainage time and filter bed surface infiltration rate.

#As part of Forensic inspection and Testing (FIT) work to determine corrective actions for suspected problems with drainage or effluent quality detected through other inspection and testing work.

#As part of Forensic inspection and Testing (FIT) work to determine corrective actions for suspected problems with drainage or effluent quality detected through other inspection and testing work.

#When little information is available about the effectiveness of a certain type of BMP in a certain environmental context, or when a new technology is being implemented for the first time in a certain context or geographic region.

#When little information is available about the effectiveness of a certain type of BMP in a certain environmental context, or when a new technology is being implemented for the first time in a certain context or geographic region.

#Where the sensitivity of the receiving water warrants a high level of inspection and testing to determine if BMP effluent quality meets design specifications or regulatory criteria.

#Where the sensitivity of the receiving water warrants a high level of inspection and testing to determine if BMP effluent quality meets design specifications or regulatory criteria.}}

===External guidance on monitoring the performance of stormwater BMPs===

===External guidance on monitoring the performance of stormwater BMPs===

===Simulated Storm Event Test Procedures===

===Simulated Storm Event Test Procedures===

For infiltration BMPs designed with flow-restricted sub-drains, continuous monitoring to evaluate drainage performance should be performed by conducting a simulated storm event test using the following stepwise procedure below:  

For infiltration BMPs designed with flow-restricted sub-drains, continuous monitoring to evaluate drainage performance should be performed by conducting a simulated storm event test using the following stepwise procedure below:  

 

#Select a date for the test when no rainfall is forecast for at least 3 days.

#Select a date for the test when no rainfall is forecast for at least 3 days.

#Install flow monitoring apparatus downstream of the sub-drain flow restrictor device.

#Install flow monitoring apparatus downstream of the sub-drain flow restrictor device.

#Determine the drainage time from the water level measurements

#Determine the drainage time from the water level measurements

#Calculate the infiltration rate based on water level measurements once flow from the subdrain has stopped as the change in storage volume over time divided by the infiltration area.  

#Calculate the infiltration rate based on water level measurements once flow from the subdrain has stopped as the change in storage volume over time divided by the infiltration area.  

#If more than 13 m³ of water (i.e., the typical capacity of water tanker trucks) is needed to fill the sub-surface water storage reservoir, a fire hydrant will need to be used as the water source.

#If more than 13 m³ of water (i.e., the typical capacity of water tanker trucks) is needed to fill the sub-surface water storage reservoir, a fire hydrant will need to be used as the water source.}}

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