Water is becoming an increasingly scarce resource for large parts of the global population. Groundwater is a significant part of the total water resource and plays an important role as a water supply for both drinking and irrigation. It is the least understood, yet most important natural resource available to mankind. The chemistry of groundwater widely depends on complex geological, geochemical, hydrogeological, and climatic factors, which control chemical evolution, giving rise to large spatial variations at a range of scales, and induce pollution issues. In addition, human activities may have an important effect on the chemistry of groundwater due to pollution from agricultural, industrial, and mining activities. The dissemination of knowledge and experience on groundwater chemistry and pollution on a worldwide scale and across disciplines is vital for the effective identification and promotion of optimal approaches for the assessment, development, and management of groundwater resources.

Over recent decades, the science of groundwater chemistry and pollution has experienced improvements, and the fundamental knowledge that exists on many of the controlling processes and groundwater impacts from point and non-point sources of pollution has been widely studied. However, many issues still require the attention of the scientific community. Particularly, in the present changing environment, caused by global climatic changes, changes in land use patterns, a growing population, increasing pressure on existing water supplies, and a variety of anthropogenic activities, tremendous challenges and uncertainties are faced when trying to monitor, characterise, and explore the origin of groundwater chemistry, predict exposure, implement remedial actions, and manage polluted systems. The need exists to advance our knowledge for understanding these changes to the chemistry of groundwater, and to develop appropriate management and remediation approaches.

This Special Issue aims at gathering the most significant contributions to theoretical development and scientific advancement relating to groundwater chemistry and pollution to help meet today’s global water challenges. We encourage studies on innovative, multidisciplinary and environmentally sound monitoring methods and tools, formation mechanisms of chemical characteristics, and remediation of groundwater pollutions. Original research and review articles are both welcome.

Potential topics include but are not limited to the following:

• Groundwater hydrogeochemistry and modelling
• Analytical chemistry of groundwater, including new techniques and instrumentation
• Investigation of groundwater pollution using monitoring methods
• Investigation of formation mechanisms of groundwater chemistry
• Underlying mechanisms causing groundwater pollution
• Environmental impact of climate change, agriculture, forestry, and land uses on groundwater chemistry and pollution
• Impact of waste or waste treatment on groundwater chemistry and pollution
• Remediation of groundwater