The Department of Energy has sent Congress a bill that would finance 75 percent of the estimated $100 million cost of cleaning up 30 million tons of uranium "tailings" at 22 mill sites in eight states.

The bill calls for the states to pay the balance of the cleanup costs, except where the uranium tails rest on Indian lands, in which case the federal government would pick up the complete cost. For the 22 sites are on Navajo Indian reservations.

The Energy Department said that low-level radiation form the tailings - the leftover debris of the process that mills uranium ore - should be cleaned up to avoid needless human exposure and contamination of rivers and streams. There are no immediate health hazards to the public from the tailings, the department said.

Cleanup costs would vary from site to site, depending on how much radio-activity is present in the sand-like tails. Some tailings will only have to be covered with landfill and fenced in; others might have to be carted away and buried.

At two sites, Ranchers Exploration and Development Co. is trying to wring the remaining uranium out of the tailings to sell the uranium out of the tailings to sell the uranium back to the federal government. The two sites are Naturiat, Colo., where 704,000 tons of tails rest, and Durango, Colo., where 1.5 million tons lie.

The sites eligible for federal funds under the new legislation are in Utah, New Mexico, Arizona, Colorado, wyoming, Texas, Idaho and Oregon. Nine of the 22 sites are in Colorado. They contain 11 tons of the 30 million tons of tailings.

Under the legislation, the Environmental Protection Agency would set public health and environmental standards for the cleanup and the Nuclear Regulatory Commission would enforce the standards. The four sites where tails lie on Indian land are at Shiprock, N.M., Mexican Hat, Utah, and Mounment Valley and Tuba City, Ariz.