This comprehensive text presents in the following sections:

• Groundwater monitoring in the regulatory and international context
• Conceptual modelling and network design
• Groundwater pollutants and other pressures
• Groundwater quality standards and trend assessment
• Case studies for groundwater assessment and monitoring in the light of EU legislation
• Groundwater measurements
• Associating external stakeholders

The editors have collected state-of-the-art information on groundwater quality assessment monitoring from the international community, providing further stimulation to the work of all parties involved in the challenges this area creates to ensure sound quality assessment of groundwater.