Detailed Stormwater Management Practice Design - Tauranga City ...

d) Adsorption.
e) Biological Processes.
SMG-9 Figure 7 - Sand Filter
SMG-9 Table 6
Stormwater Management Function – Sand Filter
Water Quality
Metals
Sediment
TPH
Flood Protection x
Stream Channel Erosion Protection x
Sand filters use filtration for treating stormwater runoff. They are similar to biofiltration in
that stormwater passes through a filtering media such as sand, gravel, compost or peat
to filter out contaminants. They are especially suited for small catchment areas and are
primarily water quality treatment practices having little water quantity benefit.
Sand filters have been used to treat stormwater runoff for years, mainly as a result of
sand filter effectiveness at removal of hydrocarbons. They are very suitable in ultraurban
environments where space is limited but are also used where more space is
available in a similar fashion to ponds.
As they are so effective at removal of finer sediments, they are prone to clogging and
require maintenance on a more frequent basis than a practice such as wetlands. They
are primarily used for high percentages of impervious surfaces where the majority of
sediments are in the coarse fraction.
Page 19 Updated 01/11/2012