Sediment Quality Indicators: Physical Indicators

Examining the physical characteristics of sediments can provide information on habitat quality—for sediment-dwelling organisms and for fish that depend on sediment for spawning—and the potential for sediment to adsorb chemicals of interest. Sediment samples are often analyzed for the following physical indicators:

Particle Size. Sediment samples are analyzed for the relative proportion of sand, silt, and clay, as defined as:

Particle	Particle Size Range (mm)
Clay	<0.002
Silt	0.002 to 0.063
Sand	0.063 to 0.2
Gravel	2 to 64

Carbon Content. Organic carbon is an indicator of organic matter, including hydrocarbons, in sediments (RAMP 2005).