Changes

Filtration is the process by which stormwater runoff is conveyed through a filter medium to remove solid particles and associated pollutants.  Several stormwater practices use filtration through sand or gravel media as the primary mechanism for treatment of urban runoff.   

Filtration is the process by which stormwater runoff is conveyed through a filter medium to remove solid particles and associated pollutants.  Several stormwater practices use filtration through sand or gravel media as the primary mechanism for treatment of urban runoff.   

Stormwater passes through a filter based on the pressure difference on either side of the filter.  In most stormwater treatment applications, the pressure difference is created by gravity (or hydraulic head).  As the filter becomes [[clogging|clogged]], higher pressure is needed to drive stormwater through the filter, until a point is reached at which flow through the treatment system must be redirected to another flow path (usually a [[bypass]] within or upstream of the system).   

Stormwater passes through a filter based on the pressure difference on either side of the filter.  In most stormwater treatment applications, the pressure difference is created by gravity (or hydraulic head).  As the filter becomes [[clogging|clogged]], higher pressure is needed to drive stormwater through the filter, until a point is reached at which flow through the treatment system must be redirected to another flow path (usually a [[overflow|bypass]] within or upstream of the system).   

==Types of filtration==

==Types of filtration==