FAQs

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)...

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...

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...

Since 1950, the USGS has collected and analyzed water-use data for the United States and its Territories . That data is revised every 5 years. As of 2015, the United States uses 322 billion gallons of water per day (Bgal/day). The three largest water-use categories were irrigation (118 Bgal/day), thermoelectric power (133 Bgal/day), and public supply (39 Bgal/day), cumulatively accounting for 90...

There are no official definitions for generic terms as applied to geographic features. The  Geographic Names Information System  (GNIS) utilizes 43 broad categories of feature classes defined solely to facilitate retrieval of entries with similar characteristics. Go to GNIS Domestic Names Feature Classes to see the full list. These categories generally match dictionary definitions, but not always...

A sinkhole is a depression in the ground that has no natural external surface drainage. Basically, this means that when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface. Sinkholes are most common in what geologists call, “ karst terrain .” These are regions where the types of rock below the land surface can naturally be dissolved by groundwater...

Sinkholes are just one of many forms of ground collapse, or subsidence. Land subsidence is a gradual settling or sudden sinking of the Earth’s surface owing to subsurface movement of earth materials. The principal causes of land subsidence are aquifer-system compaction, drainage of organic soils, underground mining, hydrocompaction, natural compaction, sinkholes, and thawing permafrost. Land...

A sinkhole is a closed natural depression in the ground surface caused by removal of material below the ground and either collapse or gradual subsidence of the surface into the resulting void. A pothole is usually a fairly small feature caused by failure of paving materials, usually associated with roads, parking lots, and airports. In the colder parts of the country, potholes become more abundant...

There is no database of sinkhole collapses for the United States, so these data are unavailable. Some individual state geologic surveys track reported collapses within their state. Many sinkhole collapses are not reported to authorities or news organizations, and many occur in rural areas where they are unobserved. Learn more: USGS Water Science School - Sinkholes

Plants naturally grow in and around lakes, but sometimes lakes and ponds can get an overgrowth of plants, algae, or bacteria. In many cases, humans are responsible. Chemicals that are used on lawns and in agriculture (like nitrogen and potassium) wash into our water systems. Once there, plants and algae have a feast on this “food”. Sometimes overgrowths of cyanobacteria (called “blooms”) can make...

Water is said to be soft if it has a low concentration of calcium and magnesium ions in it, while hard water has a high concentration of calcium and magnesium. The minerals in hard water often react with most soaps to create a "soap scum," which is an insoluble substance that can temporarily adhere to your hands or the shower walls. When using hard water, you may have a harder time working your...

In the U.S., about 13 percent of all water used is saline water . But saline water can only be used for certain purposes. The main use is for thermoelectric power-plant cooling. About 5 percent of water used for industrial purposes is saline, and about 53 percent of all water used for mining purposes is saline. Saline water can be desalinated for use as drinking water by putting it through a...