Parameter Tree:
EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > WATER QUALITY/WATER CHEMISTRY > SOLIDS > TOTAL DISSOLVED SOLIDS

Definition:
Materials less than 0.45 micrometer in length, as distinguished from suspended solids and other particulate matter, which are greater than 0.45 micrometer in length.

Reference:
Adapted from: Dictionary of Earth Science, 5th ed.. 1997. Sybil Parker, ed. in chief. McGraw-Hill.