Describes aquifer tests, such as pump test, tracing or any other procedures aimed at estimating groundwater or aquifer properties. OGC WaterML 2.2 Part 4 - GroundWaterML 2 is an OGC Standard. Copyright (c) 2016 Open Geospatial Consortium. To obtain additional rights of use, visit http://www.opengeospatial.org/legal/ . Signature class representing a aquifer test (or pump test). It describes the inputs, outputs, and methods associated with such a test.