Several geophysical methods have been successfully used in both groundwater development and groundwater contamination investigations. The most suitable method or combination of methods varies with each geological situation and the objective of the exploration. Advantages of geophysics over test drilling include an ability to cover greater distances or areas for properties that may be indicative of water bearing potential or degree of groundwater contamination. Commonly used methods include: 

• Seismic refraction/reflection
• Electrical resistivity
• Micro-gravity
• Terrain conductivity
• Ground penetrating radar (GPR)
• Borehole geophysics
• Magnetic field surveys

Successful implementation of any of the methods or combinations can used to minimize the amount of test drilling and installation of observation/monitoring wells in a subsurface investigation.