Grit consists of a variety of particles including sand, gravel and other heavy, discrete inorganic materials.
According to the United States Environmental Protection Agency’s Wastewater Technology Fact Sheet, “…grit is traditionally defined as particles larger than 0.21 mm (0.008 in.) (65 mesh) and with a specific gravity of greater than 2.65 (U.S. EPA, 1987)…”CLICK HERE FOR EPA FACT SHEET.
Most grit collected at WTTPs – nearly 90 percent on average – is larger than 70 mesh in size. In some coastal areas, smaller grit particles down to 100 mesh can be more common.
Sieve Mesh # | Inches | Microns | Similarly-Sized Material |
---|---|---|---|
14 | .0555 | 1400 | – |
28 | .0280 | 700 | Beach Sand |
60 | .0098 | 250 | Fine Sand |
100 | .0059 | 150 | – |
200 | .0029 | 74 | Portland Cement |