Idaho National Laboratory Project Office (INLPO)
The mission of the U.S. Geological Survey (USGS) at the Idaho National Laboratory Project Office (INLPO) is to implement a comprehensive groundwater monitoring and hydrogeologic studies program. This program focuses on evaluating the availability and movement of water within the eastern Snake River Plain (ESRP) aquifer, in alignment with the Department of Energy's (DOE) strategic goal of environmental protection and sustainability.
Our responsibilities extend to describing the processes that govern the fate of contaminants, conducting hydrologic modeling, and providing independent reviews of hydrogeological data and reports submitted by the DOE and its contractors to the Environmental Protection Agency and the State of Idaho.
With a legacy spanning over 75 years, USGS scientists at the INL have pioneered advancements in groundwater flow modeling, geochemistry research, unsaturated zone studies, and volcanic hazards assessments (see Bartholomay, 2022). The USGS INLPO has drilled or overseen the drilling of over 300 wells and collected extensive data from more than 475 sites, including over 72,000 water level measurements, 22,000 water-quality samples, 1,500 geophysical logs from 137 sites, and 1,500 surface water measurements. Our commitment to scientific inquiry is reflected in the publication of more than 385 scientific papers.
Eastern Snake River Plain
In collaboration with the DOE's Idaho Operations Office, the USGS has conducted extensive studies on the hydrology and geology of the Idaho National Laboratory (INL) to enhance understanding of water movement and the transport of chemical and radioactive wastes through the eastern Snake River Plain (ESRP) aquifer, particularly regarding historical waste disposal practices.
The INL is located in the west-central region of the ESRP, a northeast-trending structural basin approximately 200 miles long and 50–70 miles wide, characterized by faults and filled with basaltic lava flows interbedded with terrestrial sediments. This basin features hundreds of basalt flows, which constitute about 85 percent of the volume of deposits in the unsaturated zones and underlying aquifer (Anderson and Liszewski, 1997). The basaltic rocks and sedimentary deposits of the ESRP form the primary groundwater source for eastern and southern Idaho, with most aquifer-hosting basalt originating from shield volcanoes visible on the modern surface of the ESRP.
Current theories regarding the dramatic subsidence of the ESRP suggest it has been sinking due to the Yellowstone hot spot caldera eruptions, creating accommodation space for a thick package of basaltic and rhyolitic lava flows interbedded with fluvial, lacustrine, and eolian sediments. The aquifer occupies the upper, more permeable portion of these volcanic rocks, while deeper layers experience hydrothermal alteration that reduces porosity and permeability, effectively sealing the rock and defining the base of the aquifer. The depth of the aquifer base varies widely, ranging from several hundred to several thousand feet below land surface, primarily inferred from electrical-resistivity surveys (Whitehead, 1986, sheet 2). Direct evidence is limited to approximately 13 deep boreholes, with altered basalt and sediment in core samples, along with increasing geothermal gradients, serving as key indicators of the aquifer's lower boundary. The USGS continues to refine the interpolated aquifer base surface using advanced software tools and newly acquired borehole data.
More Information
For more information about the geohydrology of the eastern Snake River Plain, please review our Fact Sheet (Bartholomay, 2017) or Professional Paper (Whitehead, 1992). You can also visit the following sites for information designed for the general public:
The mission of the U.S. Geological Survey (USGS) at the Idaho National Laboratory Project Office (INLPO) is to implement a comprehensive groundwater monitoring and hydrogeologic studies program. This program focuses on evaluating the availability and movement of water within the eastern Snake River Plain (ESRP) aquifer, in alignment with the Department of Energy's (DOE) strategic goal of environmental protection and sustainability.
Our responsibilities extend to describing the processes that govern the fate of contaminants, conducting hydrologic modeling, and providing independent reviews of hydrogeological data and reports submitted by the DOE and its contractors to the Environmental Protection Agency and the State of Idaho.
With a legacy spanning over 75 years, USGS scientists at the INL have pioneered advancements in groundwater flow modeling, geochemistry research, unsaturated zone studies, and volcanic hazards assessments (see Bartholomay, 2022). The USGS INLPO has drilled or overseen the drilling of over 300 wells and collected extensive data from more than 475 sites, including over 72,000 water level measurements, 22,000 water-quality samples, 1,500 geophysical logs from 137 sites, and 1,500 surface water measurements. Our commitment to scientific inquiry is reflected in the publication of more than 385 scientific papers.
Eastern Snake River Plain
In collaboration with the DOE's Idaho Operations Office, the USGS has conducted extensive studies on the hydrology and geology of the Idaho National Laboratory (INL) to enhance understanding of water movement and the transport of chemical and radioactive wastes through the eastern Snake River Plain (ESRP) aquifer, particularly regarding historical waste disposal practices.
The INL is located in the west-central region of the ESRP, a northeast-trending structural basin approximately 200 miles long and 50–70 miles wide, characterized by faults and filled with basaltic lava flows interbedded with terrestrial sediments. This basin features hundreds of basalt flows, which constitute about 85 percent of the volume of deposits in the unsaturated zones and underlying aquifer (Anderson and Liszewski, 1997). The basaltic rocks and sedimentary deposits of the ESRP form the primary groundwater source for eastern and southern Idaho, with most aquifer-hosting basalt originating from shield volcanoes visible on the modern surface of the ESRP.
Current theories regarding the dramatic subsidence of the ESRP suggest it has been sinking due to the Yellowstone hot spot caldera eruptions, creating accommodation space for a thick package of basaltic and rhyolitic lava flows interbedded with fluvial, lacustrine, and eolian sediments. The aquifer occupies the upper, more permeable portion of these volcanic rocks, while deeper layers experience hydrothermal alteration that reduces porosity and permeability, effectively sealing the rock and defining the base of the aquifer. The depth of the aquifer base varies widely, ranging from several hundred to several thousand feet below land surface, primarily inferred from electrical-resistivity surveys (Whitehead, 1986, sheet 2). Direct evidence is limited to approximately 13 deep boreholes, with altered basalt and sediment in core samples, along with increasing geothermal gradients, serving as key indicators of the aquifer's lower boundary. The USGS continues to refine the interpolated aquifer base surface using advanced software tools and newly acquired borehole data.
More Information
For more information about the geohydrology of the eastern Snake River Plain, please review our Fact Sheet (Bartholomay, 2017) or Professional Paper (Whitehead, 1992). You can also visit the following sites for information designed for the general public: