In the United States, data depicted on blue lines,
the color of surface water features on topographic
maps, have been compiled by the Unites States
Geological Survey (USGS) into seamless national
hydrography datasets at scales of 1:100,000 and
1:24,000, but no equivalent national hydrogeology
dataset exists. Subsurface hydrogeologic data
are measured and archived by many federal, state,
and local groundwater agencies in a fragmented
way without a common means of data access and
synthesis. The lack of a systematic organization of
hydrogeologic and groundwater data means that
their formats vary from state to state, from location
to location, and from project to project. A new
groundwater investigation can be like an Easter
egg hunt, where you search around for the basic
data needed to support the investigation, coping
with many disparate data types and formats from
different data sources.