If the ground filters water, is groundwater always clean?

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-Quality Assessment (NAWQA) Program of the USGS. Chloroform and other trihalomethanes, the most commonly detected compounds, were found in about 9...

Some counties offer free well water testing, so check with your county first. If they don't, use this EPA website to find a list of state-certified laboratories in your area that do water testing, or contact your county or state health department or your State Certification Officer for assistance. Prices will vary depending on the laboratory and the test(s), but most people consider the cost to be...

See our map of water hardness (as calcium carbonate) in surface water of the United States. Hardness data (reflecting mostly calcium, plus a little magnesium) for individual drinking-water suppliers is at the EPA Office of Ground Water and Drinking Water website. It is important to note that the U.S. Environmental Protection Agency (EPA) has not set a legal limit or standard for hardness in water...

The brown stain is from a large amount of iron in your water. It is closely related to simple rust that you see on metal, which is iron oxide. Your water probably comes from groundwater that filtered through rocks containing iron-rich minerals on its way to the well. Learn more: Water Color USGS Drinking Water and Source Water Research

Once in a while you get a glass of water that 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. Like any bubbles, the air rises to the top of the water and goes into the air, clearing up the water. The water in the pipes coming into your house might be under a bit of pressure. This causes gases (air)...

The best way to learn about your local drinking water quality is to read the annual drinking water quality report/consumer confidence report that water suppliers now send out by July 1 of each year. The reports are often sent out with water bills, but they may be sent separately. The reports tell where drinking water comes from, what contaminants are in it, and at what levels. The U.S...

Naturally-occurring organic compounds are created when plant material decays in lakes and reservoirs. Those organic compounds frequently cause musty, earthy odors, especially toward the end of summer. The odors can be objectionable, but generally are not harmful to health. However, odors can be caused by other constituents as well, so you might want to call your local Health Department and mention...

Your water might be affected by iron, which is a commonly-occurring constituent of drinking water. Iron tends to add a rusty, reddish-brown (or sometimes yellow) color to water. If the color is more black than red, your water might contain a combination of iron and manganese. Both of these metals can cause staining of plumbing fixtures or laundry, but they are not known to cause health problems...