welltype

Welltype is a term used in hydrogeology and water-resource management to describe a classification scheme for wells based on construction method and intended use. The term is commonly employed in data standards and regulatory databases to facilitate consistent recording and retrieval of information about groundwater wells.

Classification typically differentiates drilled wells, dug wells, driven wells, and monitoring or observation wells, as well as production, injection, landfill/leachate, and geothermal wells. Some systems also include abandoned or decommissioned wells as a distinct subtype. The primary criteria for a welltype include construction method, depth range, casing and screen configuration, and the presence or absence of pumping equipment.

In practice, welltype codes are used in permitting, water-resource planning, groundwater modeling, and environmental reporting. They enable agencies and researchers to filter datasets by well characteristics, compare conditions across regions, and track changes over time. In addition to construction-related attributes, welltype records often link to aquifer, land-use, and geospatial data to support resource management.

Definitions of each welltype may vary by jurisdiction, leading to inconsistencies between datasets. Efforts to standardize welltype nomenclature exist in some national and regional programs, but no universal international standard is yet universally adopted. Users should consult local regulations and data dictionaries when interpreting welltype values.

See also: Drilled well; Dug well; Driven well; Monitoring well; Injection well; Geothermal well.