Toxic Substances Hydrology Program

A well pump in rural North Dakota.

USGS Hydrologic Technician assisting with collection of downwelling porewater samples in a PFAS-impacted lake on Cape Cod.

Visitors at Winnewissa Falls in Pipestone National Monument

Benthic macroinvertebrate taxa collected from Straight Run, Tioga County, Pennsyvania, USA. 

This image is a cropped rendition of  two aerial images that demonstrate satellite-derived cyanobacteria concentrations in surface waters from an area in Florida. The top image is true-color photograph, and the bottom image is from the Medium Resolution

(A). Algal bloom magnitude in Florida lakes in 2011 before normalization and (B) after normalization by lake surface area. Area-normalized magnitude (km⁻²) of selected lakes provided as part of bar labels in parenthesis. Bar height and color are proportional to annual bloom magnitude (in A) and annual area-

Map of the study region showing the location of lakes in (A) Florida and (B) Ohio. In total, 135 lakes in Florida and 21 lakes in Ohio, were resolvable with the full resolution MERIS data and are used in this study. Land and lakes are shown in gray and blue colors respectively.

The cyanobacteria Gleotrichia shown under a microscope from a water sample collected at Ek Lake Trail, a popular recreational area in Kabetogama Lake where algal blooms frequently occur. Gleotrichia  can produce microcystin.

An algal bloom forming in Kabetogama Lake near Kabetogama Visitor Center, Voyageurs National Park

Photo of the Deleware River near Lambertville, NJ and New Hope, PA.

Scientists reviewing data to determine instrument performance at the Algal Toxins Laboratory in Lawrence Kansas.