Water leaving our homes generally goes either into a septic tank in the back yard where it evaporates or seeps back into the ground, or is sent to a sewage-treatment plant through a sewer system.
This seems like a pretty straightforward question, but there are some interesting issues that come up in making a response.
The terms 'soft water' and 'hard water' are important here. Water is said to be soft if it has a low concentration of calcium and magnesium ions in it, and hard water has a high concentration of calcium and magnesium.
Once in a while you get a glass of water, and it looks cloudy; maybe milky is a better term. After a few seconds it miraculously clears up! The cloudiness is due to tiny air bubbles in the water.
The brown stain is from a large amount of iron in your water. It is closely related to simple rust you see on metal, which is iron oxide.
USGS protocols for the collection of groundwater and surface-water samples have been published in the report National Field Manual for the Collection of Water-Quality Data. The National Fie
Volatile organic compounds (VOCs), which are widely used in the manufacture of many products including refrigerants, plastics, adhesives, paints, and petroleum products, have been detected in about one-third of the wells sampled by the National Water-Q
This Ground Water Atlas of the United States is a series of USGS print publications that describe the location, the extent, and the geologic and hydrologic characteristics of the important aquifers
Our USGS Mine Drainage Activities website has a lot of good information on this topic, including links to USGS programs, activities, and featured articles.
The EPA Office of Ground Water and Drinking Water Web page Drinking water and health: What you need to know has a link to 'What are the health effects of contaminants in drinking water?' This lin