The chapter evaluates the origin of natural gas, the principles of hydraulic fracturing, and provides the magnitude of water use for hydraulic fracturing, conventional gas drilling, and electricity generation. The chapter presents the changes of the water footprint of hydraulic fracturing and water intensity over time in the USA and China. The chapter draws upon data from emerging scientific reports in the USA to explore the global implications of unconventional energy for other countries with shale gas potential. The chapter presents the major organic constituents associated with frac water used for hydraulic fracturing. The origin, geochemistry, and volume of flowback and produced water and their impact on water resources are also presented. The chapter discusses the chemical composition of produced and flowback waters, the contaminants in these wastes. The chapter explores the debate on the effect of stray gas contamination. The chapter discusses the mechanisms of potential groundwater and surface water contamination. The chapter evaluates the mechanism of coalbed methane extraction and environmental implications. The chapter discusses the different regulations and possible safeguards to protect fresh water resources from hydraulic fracturing.