Images

Louisiana RiverPro Mount

Sim Rivera demonstrating a groundwater model to children at the Shinnecock Nation Earth Day outreach event.

USGS responsds to recent flooding near Houston, Texas on April 20, 2016. 

USGS Hydrologist Travis Smith makes a wading (section-by-section) discharge measurement at Moyer Creek stream gauging station near Frankfort,  NY  to allow for better estimates of streamflow during ice-affected periods in winter.

Looking upstream from gage site at Trinity River at Commerce Street Bridge.

In the earlier years of streamgaging, large “stilling wells” were constructed to contain the equipment needed to collect streamflow data. Historically, most of the streamflow equipment may have been located in these large structures, which were placed in the middle or next to the stream.

Instrumentation for measuring real-time groundwater properties at the SGW-93 bedrock-aquifer public-supply well pump house in Seabrook, NH. Read the journal article.

Modern-day USGS streamgage at Elm Fork Trinity River near Carrollton, Texas.

A modern 21^st century version of a streamgage structure.

Nearly completed construction of a streamgage structure in 1955 at Elm Fork Trinity River near Carollton, Texas.

This 1922 photo shows an early USGS streamgage on the Trinity River in Dallas.

Currently, most of the streamflow equipment is located on a streambank or bridge. Large structures are no longer needed at most streamgage locations. Today, streamgage equipment can be contained in small metal shelters that are located on streambanks or bridges.

This 2014 photo shows the new location of the USGS streamgage that measures high flows on the Trinity River in Dallas. The gage was once located on a pier, but in 1975 was moved next to the stream. 

Construction in 1939 of a streamgage structure at Elm Fork Trinity River near Carrollton, Texas.

One of the oldest versions of a streamgage structure constructed in Texas.

A close-up view of the top part of one of the oldest streamgage structures constructed in Texas.

Walker Lake in Nevada on a Spring day

Coal tar is a byproduct of the coking, liquefaction, or gasification of coal. Coal-tar pitch is the residue that remains after the distillation of coal tar. Coal tar and coal-tar pitch are used in coal-tar-based sealcoat products, although use of coal-tar pitch is more common than use of coal tar. Both coal tar and coal-tar pitch are known human carcinogens.

Concentrations of polycyclic aromatic hydrocarbons (PAHs) in settings near pavement sealed with coal-tar-based sealants were substantially higher than concentrations in settings where coal-tar sealant was not used.

Coal-tar-based sealcoat is a potent source of PAHs and related chemicals. Worn particles of coal-tar-based sealcoat are transported by rain, wind, tires, and even our feet from pavement to other environmental settings. Sealcoat product (A), after it dries, gradually abrades to a powder and becomes part of the dust on the pavement (B).

Cool, clear rivers of the Texas Hill Country attract visitors for many recreational opportunities. Here, a family enjoys paddleboarding at Schreiner Park during spring break in Kerrville, Texas.