The American Society for Testing and Materials (ASTM) Committee D18 on Soil and Rock develops consensus standards related to exploration for and quantitative availability of groundwater as it occurs in the soil and rock. The 530‐member committee has 20 existing ASTM standards and has, at various stages of development, 25 draft standards that are useful for investigations of available supply, potential and existing pollution, artificial recharge, land subsidence, and other problems related to groundwater.