Kiewit Western Company will pay $80,000 in civil penalties for water quality violations at construction sites on Highway 260 and Highway 191 in Gila and Greenlee counties.
Arizona Department of Environmental Quality Director Steve Owens said that in 2002, while involved in construction along Highway 260, the company built a drainage ditch and bulldozed a total of more than 100,000 gallons of silt-laden stormwater into forest streams in Gila County.
During 2002-2003, the silt drained into several waterways that flow into Christopher Creek and, later, Roosevelt Lake, with each discharge lasting from at least one day to two weeks or longer.
"Kiewit's carelessness contaminated some of Arizona's most precious water resources," Owens said. "We will not tolerate this kind of pollution."
The U.S. Fish and Wildlife Service has designated sections in Tonto Creek, 12 miles downstream of Christopher Creek, as critical habitat for the spiked dace and loach minnow, both protected fishes under the federal Endangered Species Act.
The discharged silt caused by Kiewit's construction activity on Highway 260 changed the color of the surface water, settled on the creek bottom and formed bottom deposits.
The pollution created risks to aquatic life and recreational uses in the creek.
In addition, at its Highway 191 bridge construction site east of Safford in 2003, Kiewit stockpiled rock and other materials that discharged into a dry wash flowing to the Gila River watershed.
ADEQ notified the company repeatedly that its erosion and sediment control structures were inadequate in light of anticipated monsoons in 2003.
In addition to violating the state's surface water quality protection laws, Kiewit also failed to comply with the state's permitting requirements regulating discharges into state water bodies.