A unit of capacity (volume) usually referring to liquid measure in the British or U. S. customary system of units. The capacity defined by the British (Imperial) gallon equals 1.20095 U.S. gallons; one U.S. gallon equals four quarts or 3.785 10 3 m3.
A unit of volume in the U.S. Customary System, used to measure liquid, equal to 4 quarts (3.785 liters) and weighs 8.3 lbs. Groundwater: The supply of fresh water found under the surface of the Earth usually found in aquifers. Groundwater often supplies wells and springs with water that is needed.
The Scots gallon was a Scottish unit of measurement of liquids that was in use from at least 1661, (possibly 15th century), until the mid 19th century. It was approximately three times larger than an Imperial gallon that was adopted in 1824.