Abstract Environmental geology is a branch of applied Earth science that examines interactions between people and the geological environment. It applies knowledge of rocks, soils, water, and natural processes to environmental problems. Its major applications include groundwater protection, geological hazard assessment, project site selection, and natural resource management. This article outlines the concept of environmental geology and explains its contribution to environmental planning and sustainable development. Keywords: Environmental geology, groundwater, geological hazards, pollution, natural resources, sustainable development. Introduction Human life depends on the geological environment. Land supports construction and agriculture, while geological formations provide water, minerals, and building materials. However, urban expansion, industrial activities, and poorly managed resource extraction can create environmental problems that require an understanding of Earth materials and processes. Environmental geology connects this understanding with community needs and development decisions. The Concept of Environmental Geology Environmental geology applies Earth science principles to understand, assess, and reduce problems arising from interactions between human activities and the natural environment. It examines rock and soil properties, groundwater movement, slope stability, and land suitability for different uses. A central principle is that safe planning requires knowledge of local geological conditions and an understanding of how a proposed activity may affect, or be affected by, those conditions. Protecting Groundwater from Contamination Groundwater can be affected by leaking wastewater, fertilizers, pesticides, and landfill leachate. Contaminant movement depends on soil and rock properties, fractures, groundwater depth, and flow direction. Geological and hydrogeological investigations help identify vulnerable areas, develop monitoring programmes, and evaluate the locations of potentially polluting activities. Although some Earth materials can filter certain contaminants or slow their movement, natural filtration does not guarantee the removal of all pollutants. U.S. Geological Survey Assessing Geological Hazards Geological hazards include earthquakes, landslides, land subsidence, and problems associated with expansive or collapsible soils. Investigating and mapping these hazards helps identify areas requiring development restrictions or specific engineering measures. Hazard assessment does not necessarily prevent natural events. Instead, it supports decisions that reduce the exposure of people and infrastructure and improve the suitability of project locations and designs. Utah Geological Survey Land-Use Planning and Waste Management Geological information is important when selecting sites for industrial facilities and waste disposal. Site assessments examine the permeability of geological layers, aquifer depth, and potential pathways for water and contaminant movement. Combining geological maps with groundwater information helps compare possible locations and identify protection and monitoring requirements. Site suitability must be established through an integrated assessment alongside appropriate design, operating practices, and environmental controls. library.isgs.illinois.edu Tools Used in Environmental Investigations Environmental geology uses field surveys, exploratory drilling, soil and water sampling, laboratory analysis, and geophysical measurements. Geographic information systems and remote sensing help integrate observations, produce maps, and examine spatial changes. An Iraqi research example is the use of geographic information systems to assess groundwater contamination risk in the Upper Al-Sanaf Marsh sub-basin in Maysan Governorate. The Iraqi Geological Journal Conclusion Environmental geology provides a scientific foundation for understanding human interactions with the Earth and making informed decisions about resources and development. Integrating geological investigations into planning helps protect water and soil, reduce the consequences of natural hazards, and support sustainable development while preserving resources for future generations. Almustaqbal University – The First University in Iraq