Water Quality

The USGS maintains sediment laboratories in several Water Science Centers and offices across the country.

USGS develops and uses “surrogate” techniques to estimate sediment at times when it can’t be physically measured through samples.

USGS collects sediment samples at thousands of locations across the U.S. using nationally consistent methods.

Harmful algal blooms (HABs) are caused by a complex set of physical, chemical, biological, hydrological, and meteorological conditions. Many unanswered questions remain about occurrence, environmental triggers for toxicity, and the ability to predict the timing, duration, and toxicity of HABs.

Wherever you live, there’s a creek or stream near you. The eighty percent of Americans who live in metropolitan areas are often unaware of the network of urban creeks—many teeming with life—that weaves through our cities and town. Nowhere are the environmental changes associated with urban development more evident than in urban streams.

From chloride to corrosivity, from pesticides to PAHs, find the most recent National Water Quality Program (NWQP) science on these topics and effects on surface water, groundwater, and ecology. Informative web pages provide an overview and links to related web pages, publications, maps, news, and data.

The USGS is evaluating the integration of small unoccupied aircraft systems – sUAS or "drones" – into USGS hydrogeophysical studies. The following projects are part of a Water Resources Mission Area demonstration and evaluation effort in collaboration with USGS Water Science Centers (WSCs) starting in June 2018.

Since 1981, the USGS has been the lead Federal agency for the monitoring of wet atmospheric deposition (chemical constituents deposited from the atmosphere via rain, sleet, and snow) for the interagency National Atmospheric Deposition Program. NADP monitoring networks provide long-term, high-quality atmospheric deposition data used to support research and decision-making.

Every day, millions of gallons of groundwater are pumped to supply drinking water for about 140 million people, almost one-half of the Nation’s population. Learn about the quality and availability of groundwater for drinking, where and why groundwater quality is degraded, and where groundwater quality is changing.

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.

Saltwater intrusion has occurred to some degree in many of the coastal aquifers of the United States. Since saltwater cannot be used to irrigate crops or be consumed by people, saltwater intrusion can be very problematic to coastal communities that rely on fresh groundwater supplies for the livelihood. The USGS studies how excessive groundwater pumping, sea level rise, and other factors contribute...