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Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

Vacant Lot Site Assessment Tips

Characterizing Surface Disturbances

Surface Crusting

A. One type of crust covers the area.

Tips: A crust is present when the top surface layer is compacted or hardened over

  • Check whether the crusting appears generally consistent and uniform throughout all disturbed surface areas. Look for one or more of the following:
  • Do some areas appear to have a lighter-weight or different-colored crust than others?
  • Are crusted areas lying next to patches of loose soil? Look particularly for loose soil areas around sides of the lot adjoining a roadway or access path.
  • Is blowsand present? Blowsand is a thin layer of loose grains that have been blown by wind currents onto the lot's surface from somewhere else (i.e. the sand layer does not originate from the disturbed lot). Blowsand usually collects in some areas more than others and does not cover more than half of the surface area on any given lot.

B. More than one type of crust. Test each crust type separately.

C. Crust in some areas, loose soil in others. Test each representative surface type separately.

D. Blowsand is present on top of a crust. Clear blowsand from surfaces to be tested.

E. No crusting. Continue below.


F. Flat Vegetation

  • Flat vegetation includes rooted vegetation or unattached vegetative debris lying horizontally on the surface. It can be alive or dead, but light wind must not be able to move it or blow it away. Examples include flat, low-lying shrubs or clumps of hay that are bunched.

G. Standing Vegetation

  • Standing vegetation has a vertical orientation. It must be rooted but can be dead or alive. It includes plants, grasses, shrubs - virtually anything rooted that is not considered flat vegetation.

H. Some areas have vegetation, others do not. Vegetation tests only apply to vegetated disturbed areas..

I. One plant or grass species..

  • Is the vegetation all one species? For example, sagebrush, mesquite, palmilla grass, and grama grass are all different types of plants or grasses.

K. Vegetation (per species) is approximately the same in height and/or width everywhere.

L. Vegetation (per species) has varying heights and/or widths.

  • Next, determine whether your vegetation varies in size. For example, if sagebrush is present, is the sagebrush similar in size throughout, or do you see variations from small to large?

Bare Uncrusted (loose) Soil

M. One type of bare loose soil covers the area.
  • The surface has bare, loose soil. If rocks or stones are on the surface that are smaller than ½ inch in diameter, ignore them.
N. There are multiple types of soil. Test each soil type separately.
  • Look to see whether more than one type of soil is present in the disturbed areas, as indicated by color or texture differences.


O. Rocks or stones about ½ inch or more in diameter are on the surface.
  • Look for non-erodible elements, such as rocks, stones or other bulk material not including vegetation. To qualify as non-erodible, the object's diameter must be larger than one centimeter. A centimeter is slightly less than ½ inch, so note whether rocks and stones at least ½ inch in diameter are present..
P. Some areas have rocks/stones and others do not. Test areas with rocks separately from areas without rocks.

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