Dry Valley/North Rasmussen Ridge Mines Dry Valley/North Rasmussen Ridge Mines Dry Valley/North Rasmussen Ridge Mines Dry Valley/North Rasmussen Ridge Mines Dry Valley/North Rasmussen Ridge Mines Dry Valley/North Rasmussen Ridge Mines Dry Valley/North Rasmussen Ridge Mines

Dry Valley/North Rasmussen Ridge Mines

Soda Springs, Idaho

Kiewit provides contract mining services for the Conda Phosphate Operations near Soda Springs, Idaho. The objective of the mining services contract is to provide between 1.5 million and 2.5 million tons of phosphate ore per year from the North Rasmussen Ridge, Lanes Creek, and/or Rasmussen Valley Mines at an annualized strip ratio ranging from 3:1 to 5:1 cubic yards of waste to a ton of ore. The mining process involves topsoil/alluvium stripping and salvage and the removal of waste burden by drilling and blasting, ripping, loading, hauling and placement for regrade. The phosphate ore is selectively mined and stockpiled near the tipples prior to screening and loading into rail cars for delivery to the Conda Plant.

Kiewit operates and maintains the mining equipment fleet consisting of a 21-cubic-yard front shovel, a 16-cubic-yard mass excavator, one 11-cubic-yard excavator, and eighteen 100-ton end dump trucks.

The phosphate is used in the phosphate fertilizer business to produce monoammonium phosphate (“MAP”), MAP with micronutrients (“MAP+”), superphosphoric acid (“SPA”), merchant grade phosphoric acid (“MGA”) and ammonium polyphosphate (“APP”). The fertilizers are used to replace soil nutrients that are lost following each harvest and to promote plant growth and flowering. The use of fertilizers to maintain crop production has become a necessity to feed the world population.