A semitrailer driven by Kerry Carpenter, 42, of New Mexico reportedly lost its brakes Sunday about three miles west of the summit of Vail Pass. He was able to exit Interstate 70 on a runaway truck ramp, but the truckload of hazardous material spilled. Less than 100 gallons of a methanol-based mixture seeped into Black Gore Creek, but water district officials shut off equipment before Vail’s drinking water was jeopardized.