Changes

==Overview==

==Overview==

Oil and Grit Separators (OGS) are Manufactured Treatment Devices (MTDs) used for water quality treatment of stormwater runoff through the removal of large particle suspended solids and associated pollutants, and debris. Some devices can also trap light liquids such as oil and other floatables. These MTDs are typically installed underground within the stormwater sewer system in an on-line or off-line configuration. They are distinguished from [[Pretreatment|Filtration-based MTDs]] by their removal of solids through settling rather than filtration.

Oil and Grit Separators (OGS) are Manufactured Treatment Devices (MTDs) used for water quality treatment of stormwater runoff through the removal of large particle suspended solids and associated pollutants, and debris. Some devices can also trap light liquids such as oil and other floatables. These MTDs are typically installed underground within the stormwater sewer system in an on-line or off-line configuration. They are distinguished from [[Filtration Manufactured Treatment Devices]] by their removal of solids through settling rather than filtration.

 

==Application==

==Application==

Oil and Grit Separators are suitable as pre-treatment to other downstream treatment systems such as ponds or LID features.  Cost effective application of OGS as [[pretreatment]] to a downstream LID practice typically requires that the practice have a single [[inlet]] with a drainage area larger than 0.2 ha.   

Oil and Grit Separators are suitable as pre-treatment to other downstream treatment systems such as ponds or LID features.  Cost effective application of OGS as [[pretreatment]] to a downstream LID practice typically requires that the practice have a single [[inlet]] with a drainage area larger than 0.2 ha.   

==Sizing==

==Sizing==

[[File:OGS Calculation Tool 2024.png|thumb|450px|link=https://wiki.sustainabletechnologies.ca/images/5/57/OGS_Review_Sheet_2024-02-05.xlsx|This is a screenshot of the latest version of STEP’s OGS Review Sheet Calculator.  The calculator has been developed to facilitate use of ISO 14034 ETV verified test data using a standard approach for all OGS MTD designs.]]

[[File:OGS Calculation Tool 2024.png|thumb|450px|link=https://wiki.sustainabletechnologies.ca/images/2/25/OGS_Review_Sheet_2024-03-12_LOCKED.xlsx|This is a screenshot of the latest version of STEP’s OGS Review Sheet Calculator.  The calculator has been developed to facilitate use of ISO 14034 ETV verified test data using a standard approach for all OGS MTD designs.]]

It is recommended that a standard sizing approach be used for all OGS units to ensure that they are evaluated based on a consistent methodology. The OGS Review Calculator provided here has been developed to facilitate application of ISO 14034 ETV test data through a standard approach applicable to all OGS MTD designs.  The Calculator is intended to be completed by municipal development review staff or their consultants to:

It is recommended that a standard sizing approach be used for all OGS units to ensure that they are evaluated based on a consistent methodology. The OGS Review Calculator provided here has been developed to facilitate application of ISO 14034 ETV test data through a standard approach applicable to all OGS MTD designs.  The Calculator is intended to be completed by municipal development review staff or their consultants to:

While more complex modelling methodologies may be used for sizing OGS devices, the final sizing recommendation should be consistent with or more conservative than that generated using the OGS Review Calculator, as the latter includes factors of safety and assumptions are more transparent. If less conservative sizing results from more refined modelling methods are to be accepted, a clear and concise rationale should be provided by the proponent to explain the key differences in assumptions and input parameters.<br>

While more complex modelling methodologies may be used for sizing OGS devices, the final sizing recommendation should be consistent with or more conservative than that generated using the OGS Review Calculator, as the latter includes factors of safety and assumptions are more transparent. If less conservative sizing results from more refined modelling methods are to be accepted, a clear and concise rationale should be provided by the proponent to explain the key differences in assumptions and input parameters.<br>

The following methods and processes are built into the tool:

The following methods and processes are built into the tool:

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{{Clickable button|[[File:Cover OGS review sheet.PNG|320 px|link=https://wiki.sustainabletechnologies.ca/images/5/57/OGS_Review_Sheet_2024-02-05.xlsx]]}}

{{Clickable button|[[File:Cover OGS review sheet.PNG|320 px|link=https://wiki.sustainabletechnologies.ca/images/2/25/OGS_Review_Sheet_2024-03-12_LOCKED.xlsx]]}}

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