The landscape near Hanford's former C Reactor might look mostly flat from a distance, but get up close and there are small ridges, indentations and rock outcroppings.
That's just what James Bernhard likes. He's a wildlife biologist and the natural resources lead for Washington Closure Hanford.
"Engineers like things square and flat," he said.
But not Bernhard.
He's made sure the heavy equipment used to fill what was essentially an open pit mine near C Reactor has not left the ground too tidy.
Washington Closure is in the midst of a major backfill campaign, filling up the holes dug to remove contamination at the nuclear reservation as much of the environmental cleanup at Hanford along the Columbia River nears completion.
During the past 20 months, workers under a DelHur Industries subcontract placed 3 million tons of backfill. That's enough to fill an area the size of a football field 900 feet high, or about one and a half times the height of the Space Needle in Seattle, said Ron Morris, Washington Closure manager for backfilling in the former reactor areas.
Workers have dug massive holes near C, D and DR reactors to chase chromium contamination in the soil down to 85 feet deep. The hole near the D and DR reactors stretches across the size of more than seven football fields.
At N Reactor, removal of contaminated soil left 98 waste sites that had to be refilled.
It's Bernhard's goal for the finished backfill at those sites to mimic nature, not a soccer field.
"Something flat has much less potential real estate," he said.
A naturally undulating, landscape with rocks provides areas with shade for plants and animals, he said, and provides shelter from the Mid-Columbia winds. It catches seeds, helping them to take root rather than being blown away. It provides places for small animals, like mice and rabbits, to hide from predators, such as coyotes. And it helps hold moisture better than flat surfaces, where wind evaporation is greater.
The majority of Hanford land is planned to be used for preservation and conservation as cleanup is completed.
It's shrub-steppe habitat, which has been described as one of the most imperiled ecosystems in the nation, said Paula Call of the Department of Energy Site Stewardship Division.
The about 15 million acres of shrub-steppe that once covered much of Eastern Washington has given way to agriculture, leaving just 5 million acres. Only three large tracts remain -- the Yakama Nation reservation, the Army's Yakima Training Center and the Hanford nuclear reservation.
"The department does recognize the ecological value of the Hanford site," Call said.
But DOE and Washington Closure also found ways to reduce costs as they backfill large areas.
That has included backfilling some areas to just 86 percent, when acceptable to Hanford regulators. Some sites, including those near reactors, still must be filled to 100 percent.
Historically, each reactor had a borrow area to provide dirt for construction, such as building roads. Now those borrow pits are part of Hanford Reach National Monument land along the south side of the Columbia River, and DOE's goal is to remove as little additional soil from them as possible.
Leaving other areas a little shallower than before cleanup begins means less fill soil has to be dug up at borrow areas near each reactor and hauled to backfill sites.
Washington Closure also is using uncontaminated debris for some of the fill to reduce the need for borrow area dirt. It has used concrete and steel from former Hanford service buildings and the metal rails from railroad tracks as fill material.
That saves the cost of loading out and hauling the material to Hanford's central landfill, the Environmental Restoration Disposal Facility. And it helps conserve space in the landfill, which has been expanded several times across shrub-steppe habitat.
In some places, including between N Reactor and the Columbia River, crews put in stakes to show others how deep they should place fill soil in different areas to create the final contoured landfill.
Heavy equipment operators are told just to leave dirt in piles, and then the last step of sculpting the ground is done as vegetation is planted.
Work has been completed on the largest single backfill site at Hanford, the deep dig near C Reactor.
"It was one big soup bowl," Bernhard said. "It was the ugliest thing you ever saw."
The land is starting to return to a more natural state. A little more than 100 acres have been seeded with native grasses and planted with 52,000 big sage, spiny hopsage and antelope bitterbrush grown from seeds collected at Hanford.
Crews have finished backfilling near N Reactor, and they now are working on the area near the D and DR reactors, the site of another dig down to 85 feet.
Workers will seed the area near N Reactor late this fall or in early spring.
"I'm thrilled with what Washington Closure Hanford has done," Call said. "It leaves the land in better ecological shape than when it started."
-- Annette Cary: 509-582-1533; firstname.lastname@example.org; Twitter: @HanfordNews