Types of Water

The Nation's rivers and streams are a priceless resource, but pollution from urban and agricultural areas pose a threat to our water quality. To understand the value of water quality, and to more effectively manage and protect the Nation's water resources, it's critical that we know the current status of water-quality conditions, and how and why those conditions have been changing over time.

Water and the chemicals it contains are constantly being exchanged between the land surface and the subsurface. Surface water seeps into the ground and recharges the underlying aquifer—groundwater discharges to the surface and supplies the stream with baseflow. USGS Integrated Watershed Studies assess these exchanges and their effect on surface-water and groundwater quality and quantity.

Groundwater is the largest source of fresh water on Earth - it's kind of a big deal. The USGS monitors, tests, and studies groundwater resources to assure one of our Nation's most precious resources remains viable for future generations.

Hydraulic fracturing, commonly known as fracking, is the process of injecting water, sand, and/or chemicals into a well to break up underground bedrock to free up oil or gas reserves. The USGS monitors the environmental impact of this practice across the country, from potential earthquakes to degraded groundwater quality.

More than 80 percent of known land subsidence in the U.S. is a consequence of groundwater use, and is an often overlooked environmental consequence of our land and water-use practices. Increasing land development threatens to exacerbate existing land-subsidence problems and initiate new ones. Subsidence detection and mapping done by the USGS is needed to understand and manage our current and...

The NASA-USGS National Blue Carbon Monitoring System project will evaluate the relative uncertainty of iterative modeling approaches to estimate coastal wetland (marsh and mangrove) C stocks and fluxes based on changes in wetland distributions, using nationally available datasets (Landsat) and as well as finer scale satellite and field derived data in six sentinel sites.

The Global Science and Data Network for Coastal Blue Carbon (SBC) brings together scientists from a wide range of disciplines. Our goal is to increase the accuracy of and confidence in local, regional, and global estimates of carbon cycle processes, fluxes, and storage as well as greenhouse gas emissions from coastal ecosystems, and to allow global access to quality controlled coastal ecosystem...

Intensive studies by the USGS National Water-Quality Assessment (NAWQA) Project in agricultural areas provide insight into how agricultural activities have altered the natural flow of water and the way that agricultural chemicals enter streams and aquifers, and in particular how nutrients affect algal and invertebrate communities in agricultural streams.

The USGS has been at the forefront of studying the impacts of acid rain for decades. How does acid rain form? What does it do to the landscape? Can it burn you like battery acid? Keep reading to find out more...

About 40 percent of the land in the United States is used for agriculture, and agriculture supplies a major part of the our food, feed, and fiber needs. Agricultural chemicals move into and through every component of the hydrologic system, including air, soil, soil water, streams, wetlands, and groundwater.

All natural waters contain some dissolved solids (salinity) from contact with soils, rocks, and other natural materials. Too much, though, and dissolved solids can impair water use. Unpleasant taste, high water-treatment costs, mineral accumulation in plumbing, staining, corrosion, and restricted use for irrigation are among the problems associated with elevated concentrations of dissolved solids.

Arsenic is a naturally occurring element, but long-term exposure can cause cancer in people. There has been a substantial amount of research done to address arsenic in groundwater and drinking-water supplies around the country. The USGS studies local and national sources of arsenic to help health officials better manage our water resources.