Pigeon Canyon in northern Arizona is just north of the Grand Canyon. Here, Pigeon Spring emerges in Pigeon Canyon just before it merges with Snake Gulch in northern Arizona.
Images
![Pigeon Canyon in northern Arizona is just north of the Grand Canyon](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/38confpigeoncynsnakegulch.073009_l.jpg?itok=SUtI_xYL)
Pigeon Canyon in northern Arizona is just north of the Grand Canyon. Here, Pigeon Spring emerges in Pigeon Canyon just before it merges with Snake Gulch in northern Arizona.
![USGS scientists installing passive sediment samplers in an irrigation ditch near Hancock, Wisconsin](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/fungicide_occurrence_photo_2_l.jpg?itok=BCjO2cYD)
USGS scientists installing passive sediment samplers in an irrigation ditch near Hancock, Wisconsin. The samplers are designed to collect suspended sediment from streams over a 3-week period.
USGS scientists installing passive sediment samplers in an irrigation ditch near Hancock, Wisconsin. The samplers are designed to collect suspended sediment from streams over a 3-week period.
![USGS scientist collecting water samples from an amphibian monitoring site](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/armi_sampling_ivermore_ca_l.jpg?itok=Nr5Jsq6g)
USGS scientist collecting water samples from an amphibian monitoring site in Livermore, California.
USGS scientist collecting water samples from an amphibian monitoring site in Livermore, California.
USGS scientist collecting water samples for pesticide analysis at Woodward Resevoir Pond near Oakdale, California.
USGS scientist collecting water samples for pesticide analysis at Woodward Resevoir Pond near Oakdale, California.
This photo shows a snow plow and road salt application truck that is used to clear snow and ice from roadways for improving traffic and pedestrian safety. The use of salt to deice pavement can be harmful to aquatic life in urban streams. The USGS is involved in studies that focus on the influence of winter runoff on aquatic ecosystems.
This photo shows a snow plow and road salt application truck that is used to clear snow and ice from roadways for improving traffic and pedestrian safety. The use of salt to deice pavement can be harmful to aquatic life in urban streams. The USGS is involved in studies that focus on the influence of winter runoff on aquatic ecosystems.
![Scanning electron microscopy (SEM) image of diatoms with zinc oxide (ZnO) nanoparticles](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/ctt_croteau_diatoms_with_zno_nanoparticles_1024.jpg?itok=IIrpaXtr)
Scanning electron microscopy (SEM) image of diatoms with zinc oxide (ZnO) nanoparticles. U.S. Geological Survey (USGS) scientists are studying the linkages between contaminant bioavailability and toxicity, especially in aquatic organisms exposed to metals and metallo-nanomaterials through solution and diet.
Scanning electron microscopy (SEM) image of diatoms with zinc oxide (ZnO) nanoparticles. U.S. Geological Survey (USGS) scientists are studying the linkages between contaminant bioavailability and toxicity, especially in aquatic organisms exposed to metals and metallo-nanomaterials through solution and diet.
![Example filled in completed Request for Mercury Analysis form](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Completed%20Form%20FO3.jpg?itok=I_RLfqZ5)
Example completed filled in Wisconsin District Mercury Laboratory Request for Analysis form.
Example completed filled in Wisconsin District Mercury Laboratory Request for Analysis form.
![USGS scientists processing samples of combined sewer overflow water collected after a storm.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/storm12_processing4_l.jpg?itok=eXzFo-Rz)
USGS scientists processing samples of combined sewer overflow water collected after a storm. The samples were analyzed for selected wastewater-related chemicals.
USGS scientists processing samples of combined sewer overflow water collected after a storm. The samples were analyzed for selected wastewater-related chemicals.
![USGS scientist dissecting a fish to determine possible effects from exposure to endocrine disrupting contaminants](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/luke_usgs_hicks_landing_10-15-08_l.jpg?itok=pEsLTcJb)
USGS scientist dissecting a fish to determine possible effects from exposure to endocrine disrupting contaminants.
USGS scientist dissecting a fish to determine possible effects from exposure to endocrine disrupting contaminants.
![USGS scientist with equipment used to inject fluids for a bioaugmentation experiment](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/nawc_bioaug_lien_2_002.jpg?itok=Bsrkjj_a)
Equipment for an Bioaugmentation Experiment at the Naval Air Warfare Center (NAWC) Research Site, West Trenton, New Jersey
linkThe set up and equipment used for the bioaugmentation experiment at a fractured-rock contamination site. The site is contaminated with trichloroethene (TCE). The bladders contain the solutions that were injected into the subsurface. The injection well is right in front of the blue barrel.
Equipment for an Bioaugmentation Experiment at the Naval Air Warfare Center (NAWC) Research Site, West Trenton, New Jersey
linkThe set up and equipment used for the bioaugmentation experiment at a fractured-rock contamination site. The site is contaminated with trichloroethene (TCE). The bladders contain the solutions that were injected into the subsurface. The injection well is right in front of the blue barrel.
USGS scientist dissecting a summer flounder. Science Feature that the image was used on was Pesticides Common in California Estuary
USGS scientist dissecting a summer flounder. Science Feature that the image was used on was Pesticides Common in California Estuary
U.S. Geological Survey (USGS) scientist Dr. Diann J. Prosser examining a ruddy shelduck in China. Dr. Diann J. Prosser was awarded the Presidential Early Career Awards for Scientists and Engineers (PECASE).
U.S. Geological Survey (USGS) scientist Dr. Diann J. Prosser examining a ruddy shelduck in China. Dr. Diann J. Prosser was awarded the Presidential Early Career Awards for Scientists and Engineers (PECASE).
![Deposit of iron-cemented stream gravel (ferricrete) with embedded wood fragments](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/ferricrete_deposits_l.jpg?itok=2GjJCSGm)
Deposit of iron-cemented stream gravel (ferricrete) with embedded wood fragments that can be age dated using radiocarbon to determine the age of the ferricrete deposit. Knowing the age of the ferricretes helps scientists determine if the associated enrichment of metals in streams occurred before or after mining in the watershed started.
Deposit of iron-cemented stream gravel (ferricrete) with embedded wood fragments that can be age dated using radiocarbon to determine the age of the ferricrete deposit. Knowing the age of the ferricretes helps scientists determine if the associated enrichment of metals in streams occurred before or after mining in the watershed started.
Mineral Creek watershed in southwestern Colorado has natural and mining-related sources of contamination. In the background of this photo is a large naturally occurring seep that discharges acidic, metal-rich water to a tributary of Mineral Creek.
Mineral Creek watershed in southwestern Colorado has natural and mining-related sources of contamination. In the background of this photo is a large naturally occurring seep that discharges acidic, metal-rich water to a tributary of Mineral Creek.
![Scientists collecting samples of runoff from a test plot during a simulated rainfall event](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/biosolids_runoff_experiment_img_0753_l.jpg?itok=HpN8YKnv)
Scientists collecting samples of runoff from a test plot during a simulated rainfall event. The field received an application of biosolids, and the runoff samples were analyzed for organic chemicals that are commonly used in our everyday lives.
Scientists collecting samples of runoff from a test plot during a simulated rainfall event. The field received an application of biosolids, and the runoff samples were analyzed for organic chemicals that are commonly used in our everyday lives.
A USGS researcher uses an ASTM-approved vacuum to collect house dust for analysis.
A USGS researcher uses an ASTM-approved vacuum to collect house dust for analysis.
Dr. David S. Blehert working in a laboratory
Dr. David S. Blehert working in a laboratory
![USGS scientist takes a sample from a northern pintail duck](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/avian_influenza_pintail_dsc00834_l_0.jpg?itok=DgmQnRwF)
USGS scientist takes a sample from a northern pintail duck (Anas acuta) to be tested for avian influenza.
USGS scientist takes a sample from a northern pintail duck (Anas acuta) to be tested for avian influenza.
Early life stage white sturgeon swimming in a laboratory tank.
Early life stage white sturgeon swimming in a laboratory tank.
![A USGS scientist prepares a tracer solution in a gas-tight bladder that will be pumped into the groundwater](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/NitrateTransToolInjection_l.jpg?itok=qEoay7Ri)
A USGS scientist prepares a tracer solution in a gas-tight bladder that will be pumped into a zone of nitrate-containing groundwater to monitor the production and consumption of nitric oxide dissolved in groundwater.
A USGS scientist prepares a tracer solution in a gas-tight bladder that will be pumped into a zone of nitrate-containing groundwater to monitor the production and consumption of nitric oxide dissolved in groundwater.
Single-well tracer tests involve injecting a tracer solution into one port of a multilevel sampling well, creating a tracer cloud in the groundwater, and then monitoring the water chemistry in the tracer cloud from the same well as the tracer cloud moves away from the well.
Single-well tracer tests involve injecting a tracer solution into one port of a multilevel sampling well, creating a tracer cloud in the groundwater, and then monitoring the water chemistry in the tracer cloud from the same well as the tracer cloud moves away from the well.