USGS researcher Jennifer Agee taking surface sediment oxidation-reduction and pH measurements at Crissy Marsh, a vegetated saltmarsh near the Golden Gate Bridge (background) in San Francisco, CA. Photographer: L. Windham-Myers.
Images
USGS researcher Jennifer Agee taking surface sediment oxidation-reduction and pH measurements at Crissy Marsh, a vegetated saltmarsh near the Golden Gate Bridge (background) in San Francisco, CA. Photographer: L. Windham-Myers.
USGS employee showing the rhizosphere (root zone) of a wetland plant, which is a critical zone for microbiological and biogeochemical processes.
USGS employee showing the rhizosphere (root zone) of a wetland plant, which is a critical zone for microbiological and biogeochemical processes.
USGS researchers collect samples of dust from a sealcoated parking lot for analysis of polycyclic aromatic hydrocarbons (PAHs). PAH concentrations in dust swept from coal-tar-sealcoated parking lots are 100s to 1000s of times higher than those swept from parking lots with other types of surfaces.
USGS researchers collect samples of dust from a sealcoated parking lot for analysis of polycyclic aromatic hydrocarbons (PAHs). PAH concentrations in dust swept from coal-tar-sealcoated parking lots are 100s to 1000s of times higher than those swept from parking lots with other types of surfaces.
![Three images, birds in wetlands, two men in a rice field, and a woman holding wetland plants.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/Wetlands-MicrobiaBiogeochem-merged.png?itok=wsBZxug1)
Left Image: Managed wetland at the Yolo Bypass Wildlife Preserve (California Central Valley) showing mixed flocks of foraging birds. Photographer: M. Marvin-DiPasquale.
Left Image: Managed wetland at the Yolo Bypass Wildlife Preserve (California Central Valley) showing mixed flocks of foraging birds. Photographer: M. Marvin-DiPasquale.
A driveway in an upscale residential community in the Lake in the Hills, Ill, is coated with coal-tar-based sealcoat. The driveway has a basketball hoop and a skateboard ramp.
A driveway in an upscale residential community in the Lake in the Hills, Ill, is coated with coal-tar-based sealcoat. The driveway has a basketball hoop and a skateboard ramp.
Driveways in an upscale residential subdivision in Lake in the Hills, Ill., are coated with black coal-tar-based sealcoat, contrasting with the white cement sidewalk.
Driveways in an upscale residential subdivision in Lake in the Hills, Ill., are coated with black coal-tar-based sealcoat, contrasting with the white cement sidewalk.
Sealcoat particles abraded from a parking lot with coal-tar-based sealcoat collect by the curbside. Also shown is a storm drain, half coated with sealcoat, down which the loose particles will be washed by runoff.
Sealcoat particles abraded from a parking lot with coal-tar-based sealcoat collect by the curbside. Also shown is a storm drain, half coated with sealcoat, down which the loose particles will be washed by runoff.
Photograph of iron(III) oxyhydroxides (yellow-brown color in two left-hand tubes collected on folded filter paper) that was produced in iron(II)-containing groundwater by the addition of nitrate. The tube on the right is a filter collected from the same groundwater before nitrate was added.
Photograph of iron(III) oxyhydroxides (yellow-brown color in two left-hand tubes collected on folded filter paper) that was produced in iron(II)-containing groundwater by the addition of nitrate. The tube on the right is a filter collected from the same groundwater before nitrate was added.
![cientists collecting bed-sediment samples from Suwanee Creek, Georgia](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/sed_benchmarks_sf_sampling_suwanee_ck_cressler_0.jpg?itok=GkiMNW0n)
U.S. Geological Survey (USGS) scientists collecting bed-sediment samples from Suwanee Creek, Gwinnett County, Georgia, on May 23, 2007.
U.S. Geological Survey (USGS) scientists collecting bed-sediment samples from Suwanee Creek, Gwinnett County, Georgia, on May 23, 2007.
Soil sampling in Eastern Colorado indicated that some chemicals introduced to nonirrigated farmland through biosolids application persisted through 468 days, and some chemicals were sufficiently mobile to be detected in soil as deep as 126 centimeters below land surface.
Soil sampling in Eastern Colorado indicated that some chemicals introduced to nonirrigated farmland through biosolids application persisted through 468 days, and some chemicals were sufficiently mobile to be detected in soil as deep as 126 centimeters below land surface.
![Three images of 1) a woman collecting sediment samples, 2) a soil core with a ruler, and 3) a cross section of a soil sample.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/SurfaceSediments-MicrobiaBiogeochem-merged.png?itok=vzHojWxL)
Left: USGS Employee Sherry Wren removing a square meter of surface sediment in pickleweed dominated marsh along the Petaluma River (California), for a study designed to investigate the role of marsh plant root zone on the cycling of mercury. Photographer: L. Windham-Myers. Date: 4/4/2006
Left: USGS Employee Sherry Wren removing a square meter of surface sediment in pickleweed dominated marsh along the Petaluma River (California), for a study designed to investigate the role of marsh plant root zone on the cycling of mercury. Photographer: L. Windham-Myers. Date: 4/4/2006
![Controlled burn at Hart Mountain National Wildlife Refuge.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/7467.jpg?itok=-mNnBGgk)
Wildfire is one of the largest sources of re-released mercury to the atmosphere and a component to the widespread movement of inorganic mercury to aquatic sediments.
Wildfire is one of the largest sources of re-released mercury to the atmosphere and a component to the widespread movement of inorganic mercury to aquatic sediments.
![Mineral particles (colloids)](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/sampling_colloids_animas_r_l.jpg?itok=I0U57tak)
A USGS scientist collects a water sample for analysis of mineral particles known as colloids. Toxic metals (such as copper in excess) bind to the particles, which are then ingested by aquatic animals.
A USGS scientist collects a water sample for analysis of mineral particles known as colloids. Toxic metals (such as copper in excess) bind to the particles, which are then ingested by aquatic animals.
![Scientist collecting water-level data from an observation well during an aquifer test](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/NAWC_PandT_AquiferTesting_l.jpg?itok=d94FjwNZ)
USGS scientist collecting water-level data from an observation well during an aquifer test at the Naval Air Warfare Center Fractured Rock Research Site, West Trenton, New Jersey.
USGS scientist collecting water-level data from an observation well during an aquifer test at the Naval Air Warfare Center Fractured Rock Research Site, West Trenton, New Jersey.
![Close up of a cyanobacteria bloom on Elysian Lake, Minnesota](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/cyanobacteria_bloom_on_elysian_mn_l.jpg?itok=TRjbT3lA)
Close up of a cyanobacteria bloom on Elysian Lake, Minnesota
Close up of a cyanobacteria bloom on Elysian Lake, Minnesota
![Voyageurs National Park](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/areal_photo_at_vnp_l.jpg?itok=vLXb6JOU)
Voyageurs National Park (VNP), a pristine setting with abundant lakes, wetlands, and streams situated on granitic bedrock, is located near northern Minnesota's border with Canada. Long-term studies at VNP have revealed trends in mercury concentration in precipitation, surface water, and fish.
Voyageurs National Park (VNP), a pristine setting with abundant lakes, wetlands, and streams situated on granitic bedrock, is located near northern Minnesota's border with Canada. Long-term studies at VNP have revealed trends in mercury concentration in precipitation, surface water, and fish.
Algal and Other Environmental Toxins Laboratory — Lawrence, Kansas. Cyanobacterial accumulation along with a dead fish
Algal and Other Environmental Toxins Laboratory — Lawrence, Kansas. Cyanobacterial accumulation along with a dead fish
![Tree swallow nestlings (Tachycineta bicolor) in a nesting box](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/tree_swallow_nestlings_dsc01717_l.jpg?itok=Re_v5Mih)
Tree swallow nestlings (Tachycineta bicolor) in a nesting box
Tree swallow nestlings (Tachycineta bicolor) in a nesting box
Typical San Francisco Bay wetland habitat dominated by pickleweed (Salicornia pacifica).
Typical San Francisco Bay wetland habitat dominated by pickleweed (Salicornia pacifica).
![The Silver Ledge Mine in the area of upper Mineral Creek](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/silver_ledge_mine_mineral_creek_co_l.jpg?itok=Tq4D9MDx)
The Silver Ledge Mine in the area of upper Mineral Creek, near Silverton, Colorado, is one of many abandoned mine sites in the watershed.
The Silver Ledge Mine in the area of upper Mineral Creek, near Silverton, Colorado, is one of many abandoned mine sites in the watershed.
![Biosolids from a wastewater treatment plant were loaded onto trucks for transport to the field](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/loader.jpg?itok=01EvJbfg)
Biosolids from a wastewater treatment plant were loaded onto trucks for transport to the field. A team of USGS scientists and their colleagues collected samples of biosolids for analysis from freshly exposed surfaces created by the machinery used to load the biosolids onto trucks.
Biosolids from a wastewater treatment plant were loaded onto trucks for transport to the field. A team of USGS scientists and their colleagues collected samples of biosolids for analysis from freshly exposed surfaces created by the machinery used to load the biosolids onto trucks.