Underground injection wells, where water and/or other substances are injected into the Earth, are used for a wide variety of purposes. The U.S. Environmental Protection Agency (EPA) regulates around 850,000 underground injection wells through its Underground Injection Control program under the Safe Drinking Water Act. The EPA defines six classes of wells based on their use:
The Environmental Protection Agency (EPA) provides a range of resources which address the health effects of contaminants in drinking water. Their Drinking Water Contaminants page provides a useful background on the sources and effects of drinking water contaminants for the following contaminant types:
The U.S. Geological Survey (USGS) reports analyzed water-use data for the United States every 5 years.
In 2015, domestic water use totaled 26,560 million gallons per day (Mgal/d), of which 88% was publicly supplied and 12% self-supplied . The total amount of water withdrawn in the United States in 2015 for all categories was 322,000 Mgal/d . Domestic water use therefore accounted for 8% of total U.S. water withdrawals in 2015.
There are different types of flood maps available.
Flood Risk Maps: The Federal Emergency Management Agency (FEMA) studies flood risk and publishes maps for each community in the United States. These risk maps show the long-term risk of flooding occurring.
"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.