UFC 3-210-10
25 October 2004
single and multiple-unit tree box filters. These would include removal of trash, debris
and sediment, replenishment of the mulch, and care or replacement of plants. During
extreme droughts, the plants may need to be watered in the same manner as any other
landscape material.
8-11.4
Corrective Actions. Plants may have to be replaced because they have
overgrown the filter, in which case their root structure may overwhelm the area of the
soils, or because of environmental stress. The grates on top of the structure may
become cracked and have to be replaced, although this should rarely occur because
they are designed to be traffic bearing. The soil may become contaminated from a spill
and have to be removed and properly disposed.
8-12
VEGETATED ROOFS. Vegetated roofs, also known as green roofs, eco-
roofs or nature roofs, are structural components that help to mitigate the effects of
urbanization on water quality by filtering, absorbing or detaining rainfall.
Figure 8-12. Vegetated Roof Cross-Section
Source: American Wick Drain Corp.
8-12.1
chemical treatment processes that filter pollutants and reduce the volume of runoff,
and, ultimately, to receiving waters. One pollutant that vegetated roofs help control, for
example, is nitrogen. While nitrogen gas occurs naturally as a major component of the
atmosphere, nitrogen compounds from automobile exhaust, agricultural fertilizers and
industrial activities can create a significant pollution problem. Airborne nitrogen
compounds can fall to the ground in dust, raindrops, or simply by gravity. When these
compounds are carried away with stormwater runoff, they contribute to eutrophication
stormwater runoff.
51
Previous Page
