FARMINGTON — The cleanup of uranium mine contamination on the Navajo reservation that started near the end of World War II is far from over, despite the accomplishments of a $100 million project by the U. S. Environmental Protection Agency, according to a recent agency report.

The U.S. EPA released a 67-page report Thursday summing up the findings of the project, which combined the efforts of the agency and the Navajo Nation EPA, as well as other governmental agencies.

"The progress that has happened so far is mixed," said Stephen Etsitty, executive director of the Navajo Nation EPA.

Since 2008, when the cleanup began, the agencies have reduced the most urgent risks to the Navajo people. They have remediated 34 contaminated homes, meaning they removed all contaminated materials and in some instances renovated or reconstructed the homes. They assessed a total of nearly 800 homes and structures in the process.

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.

The agencies still say that there is much more to do and to study.

"This effort has been a great start to addressing the toxic legacy of uranium mining on Navajo lands," Jared Blumenfeld, EPA regional administrator for the Pacific Southwest.

More than 500 abandoned uranium mine locations and thousands of mine features, such as pits, trenches and holes still have elevated levels of uranium, the report said.

"We're going to continue to push," Etsitty said.

The land is naturally rich in uranium, a radioactive ore, but many of the areas that have unsafe levels are dangerous because of former mining efforts, the report said.

The federal government mined uranium at the close of World War II for weapons development. By 1986, the government had extracted approximately four million tons of ore.

Many of the people who worked in the mines were Navajo, and their families lived nearby. As a result, many of the workers and families were exposed to radiation, and some of the families later attributed health issues to that exposure.

Though the mining itself stopped in the mid-'80s, the areas surrounding the work sites still were contaminated, along with many of the water sources, the report said.

Initially, the U.S. and Navajo Nation EPAs asked for $500 million to cover the estimated costs of the cleanup. They received $400 million short of their request, though the agencies hope to ask for more the near future.

"While there have been accomplishments that improved some conditions, we still need strong support from the Congress and the federal agencies to fund the cleanup of contaminated lands and water," said Navajo Nation President Ben Shelly, "and to address basic public health concerns due to the legacy of uranium mining and milling."

Cleanup funding, however, is not guaranteed. The agencies expect they will receive some money, but there is no telling how much. They also have no idea how long it will take for the cleanup because each site has different needs.

"One site could have very small amounts of contaminated material, but it may be very contaminated. Another site may have a large quantity of contaminated material, but it could have very low amounts of contamination," Etsitty said.

When asked how worried he was about the future of uranium cleanup projects on the reservation, Etsitty paused and said "very."