Monitoring groundwater quality and aquifer conditions can detect contamination before it becomes a problem. The appropriate type of monitoring and the design of the system depends upon hydrology , pollution sources, and the population density and climate of the region. There are four basic types of groundwater monitoring systems: ambient monitoring, source monitoring, enforcement monitoring, and research monitoring.
Ambient monitoring involves collection of background water quality data for specific aquifers as a way to detect and evaluate changes in water quality. Source monitoring is performed in an area surrounding a specific, actual, or potential source of contamination such as a landfill or spill site. Enforcement monitoring systems are installed at the direction of regulatory agencies to determine or confirm the origin and concentration gradients of contaminants relative to regulatory compliance. Research monitoring wells are installed for detection and assessment of cause and effect relationships between groundwater quality and specific land use activities.