A cubic yard of dry gravel weighs approximately 2,970 pounds. Gravel collected from water weighs approximately 1,620 pounds per cubic yard. Sand and gravel, also known as aggregates, result from mining.
Aggregates are essential for use in the building of roads and the production of concrete. They are also used in the manufacturing of glass. Instances of sand casting in both steel and iron foundries use aggregate as well. Snow and ice controls also require the use of aggregates as does petroleum extraction.
After a mine is closed, the land returns to agricultural use, or sandpit lakes are used for lakeshore housing developments. Aside from human inhabitants, the lakes create homes for local wildlife.