LSI	Description
5	Very sparsely distributed minor ground effects include sand boils up to 0.5m (1.5 ft) in diameter, minor ground fissures with openings up to 0.1m (0.3 ft) wide, ground settlement up to 25 mm (1 in.). Effects lie primarily in areas of recent deposition and shallow groundwater surface, such as active floodplains.
10	Sparsely distributed ground effects include sand boils up to 1m (3 ft) in diameter, ground fissures with openings up to 0.3m (1 ft) wide, ground settlement of a few inches over loose deposits such as trenches or channels filled with loose sand. Slumps with up to a few tenths of a meter displacement along steep banks. Effects lie primarily in areas of recent deposition with a groundwater surface less than 3m (10 ft) deep.
30	Generally sparse but locally abundant ground effects include sand boils up to 2m (6ft) in diameter, ground fissures up to several tenths of a meter wide, some fences and roadways noticeably offset, sporadic ground settlements as much as 0.3m (1 ft), and slumps with 0.3 m (1 ft) of displacements common along steep stream banks. Larger effects lie primarily in areas of recent deposition with a groundwater surface less than 3m (10 ft) deep.
50	Abundant effects include sand boils up to 3m (10 ft) in diameter that commonly unite into bands along fissures, fissures with widths up to 1.5 m (4.5 ft), fissures generally parallel or curve toward streams or depressions and commonly break in multiple strands. Fences and roadways are offset or pulled apart as much as 1.5 m (4.5 ft) in some places, ground settlement of more than 0.3 m (1 ft) occur locally. Slumps with a 1 m (3 ft) of displacement are common in steep stream banks.
70	Abundant effects include many large sand boils up to 6 m (20 ft) in diameter that commonly unite along fissures, long fissures parallel to rivers form many openings as wide as 2 m (6 ft), many large slumps along streams and other steep banks, some intact masses of ground between fissures displaced 1 to 2 m (3 to 6 ft) down gentle slopes, frequent settlements of more than 0.3 m (1 ft).
90	Very abundant ground effects include numerous sand boils with 30% or more of some areas covered with sand, many long fissures with multiple parallel streams with openings as wide as 2 m or more, some intact masses of ground between fissures are horizontally displaced a couple of meters down gentle slopes, large slumps are common in stream and other steep banks, ground settlements of more than 0.3 m (1 ft) are common.