12.1: Water - Some Unique Properties 12.2: Water in Nature Water 's influence on the world around us is affected by its unique properties some of which where discussed in the previous section. Without water, life might not be able to exist on Earth, and it certainly would not have the tremendous complexity and diversity that we see. 12.3: Chemical and Biological Contamination 12.4: Groundwater Contamination to Tainted Tap Water 12.5: Water Who Uses It and How Much? 12.6: Making Water Fit to Drink 12.7: 14.7?- Making Water Fit to Drink 12.8: Wastewater and Sewage Treatment Thumbnail: Acid mine drainage in the Rio Tinto River. (Public Domain; Carol Stoker @ NASA via ).