A team of lab scientists visited Shiprock last month to help install an instrument that will determine whether water is reaching contaminated soil. The tribe activated the instrument — a soil moisture monitoring system that looks like a 3-foot tall triangular configuration of silver pipes — this week.
The contaminated soil holds toxic levels of uranium, a radioactive material that was mined for several decades on the Navajo Nation. Some of the uranium contaminated the ground and water around the mines, according to the Environmental Protection Agency.
The mines are scattered across the Navajo Nation, most of them in northeastern Arizona.
It is believed that some of the people living in and around these mines have later suffered health problems, EPA officials have said.
To prevent further issues, much of the material with elevated levels of uranium has been contained in waste cells, areas designed to hold material without exposing it to the surrounding environment, including water that may fall on or seep into the ground.
Scientists from the Lawrence Livermore National Laboratory, based in Livermore, Calif., will be working with the Shiprock office of the Abandoned Mine Lands Reclamation Project to ensure that the cells are keeping all moisture from the contaminants.
If moisture, including groundwater or rain water, were to reach the contaminants, it could go back into the water cycle and further contaminate the environment.
Michael Taffett, a hydrogeologist with the lab, said that the soil moisture monitoring system is "pretty common technology now."
Taffett and others are working with the Shiprock office to help Navajo officials learn about the system so that they can collect the data themselves.
Taffett and employees of the Navajo Nation Abandoned Mine Lands Reclamation Project in Shiprock planted the soil moisture monitoring system instruments in four locations. They planted four monitors in three of the sites and three monitors in one the locations.
"We're basically trying to monitor how much rainfall is going into the ground," said Melvin Yazzie, senior reclamation specialist for the Shiprock office of the Navajo Nation Abandoned Mine Lands Reclamation Project. "There's still a lot of uranium mine sites that still need cleaned up."
The project is expected to cost about $172,000. It started in October 2012, when the office received the funding from the EPA, and it is scheduled to last through October this year.
"This will determine how effective our reclamation activities have been," Yazzie said.
Since 2008, the EPA and the Navajo Nation Environmental Protection Agency have reduced the most urgent risks to the Navajo people, according to a January 2013 EPA report.
They have remediated 34 contaminated homes, meaning they have removed all contaminated materials and in some instances renovated or reconstructed the homes. They assessed nearly 800 homes and structures altogether, most of them in northeastern Arizona.
The agencies provided safe drinking water for 1,825 families and performed stabilization or cleanup work at nine abandoned mines. They assessed 240 water supplies and 520 mines altogether, most of them also in northeastern Arizona.
Jenny Kane can be reached at email@example.com; 505-564-4636. Follow her on Twitter @Jenny_Kane.