A well log is a detailed record of the geological formation through which a well is drilled. The log also contains the location, owner name, driller name, and well water production. Well logs must be submitted to the state Department of Ecology within 30 days of a well's completion. Well logs are required for both permit exempt wells and non-permit exempt wells.
There are two types of wells: water wells (for water extraction) and resource wells (for water monitoring and sampling). Water extracted from water wells is used for many purposes including agricultural irrigation, industrial uses, and residential drinking water.
Between 1940 and 2017, 16,912 water well reports have been logged; the completion date for 2,433 of these is unknown and therefore not represented in the chart above. Between 1988 and 2007, over 300 water wells were recorded each year. Since then, the rate has fluctuated between 100 and 300 per year.
Permit Exempt Wells
In Washington State, prospective water users must obtain authorization in the form of a water right permit or certificate from the state Department of Ecology before withdrawing groundwater. The groundwater permit exemption allows the users of small quantities of groundwater to construct wells and develop their water supplies without first obtaining a water right permit from the state Department of Ecology. For more information about wells and water rights, the state Department of Ecology has information on: