Hydrologic Investigations near the Remote Handled Low-Level Waste Facility

Science Center Objects

The U.S. Department of Energy has proposed a location for a new facility to store waste at the INL. In the unlikely event that waste leaks from the facility, it will be important to monitor whether the contamination reaches the aquifer and baseline information is need before the facility is built.

Because we need to know how water and contaminants may travel through the aquifer, we need to gather geophysical, hydraulic property, and water-quality information about the subsurface.

We drilled one new well upgradient and two new wells downgradient of the new facility. At this site, the water level is about 490 ft below land surface; we are monitoring the water quality of the upper 50 ft of the aquifer. We collected core and geophysical logs to about 550 ft below land surface. We measured hydraulic properties from the unsaturated zone and modeled preferential and diffuse flow and perching mechanisms in the unsaturated zone.

Core material from the first well USGS 136 indicated 8 sediment layers in the upper 560 ft that ranged in thickness from 1 to 22 ft. Core material from the second well indicated 4 sediment layers in the upper 543 ft of the hole. Water-quality information from the three wells (USGS 136, 140, and 141) indicated that concentrations of tritium, sulfate, and chromium were affected by wastewater disposal at the Advanced Test Reactor Complex.