Yosemite Rock-Fall Theory Dismissed A geologist's link to restrooms lacks support, officials say. By Mark Grossi The Fresno Bee - November 3, 1999 Water from restroom septic systems may have started two massive, fatal rock falls in Yosemite National Park during the past three years, says an East Coast research geologist who investigated the slides. But the National Park Service has dismissed his suggestions to study the theory more thoroughly, said Chester "Skip" Watts, director of Radford University's Institute for Engineering Geosciences in Virginia. Watts' theory surfaced about a month ago at a meeting of the Association of Engineering Geologists in Salt Lake City. Park Service officials have checked out his theory and say it lacks merit. "We have been told by several reputable geologists that he is out in left field on this," Scott Gediman, chief of public affairs for Yosemite National Park, said Monday. "A lot of traditional science does not support what he's saying." Several experts Tuesday declined to publicly discuss Watts' theory, saying they did not know enough about it. They said rock fall has been occurring in Yosemite Valley for thousands of years, and it is largely unpredictable. Watts said he understood the reaction from Yosemite and other scientists. The issue is sensitive because the federal government might be sued if park facilities were somehow involved in the rock fall. But Watts said that if his theory is correct, park officials are blameless because they could not have known about the problem. He said the public's safety is his primary concern now. "We're not saying conclusively that the waste-water system triggered the slides," Watts said Tuesday. "We're saying we have a responsibility to do more testing. People could be hurt." In 1996 and last June, people were killed in major rock falls from Glacier Point, a feature jutting out from the granite cliffs around Yosemite Valley. On July 11, 1996, tons of rock broke off of Glacier Point and plunged 2,400 feet to Happy Isles on the valley floor. The rock, moving at several hundred miles per hour, vaporized when it hit the ground. The concussion knocked down huge trees, which crushed and killed Emiliano Morales, 20, of Montebello, who was standing near an ice cream stand. Fourteen other people were injured; one woman was left paralyzed. The Morales family filed a request for payment from the Park Service. Department of Interior solicitors would not allow the claim, saying the federal government was not responsible for the death. The other rock fall occurred this year on June 14, when more granite broke loose below another part of Glacier Point, sending boulders crashing into Curry Village. Peter Terbush, 22, a rock climber from Gunnison, Colo., was killed. About a year after the 1996 rock fall, Watts and four others rappelled off Glacier Point to inspect the area where the rock fall began. Above the site, Watts said he saw a broken waste-water pipe pouring water into the area. He traced the flow back to restrooms that were connected to septic boxes by the pipe. He returned to Yosemite this year after the June slide and found the rock release site was directly below the new Glacier Point restroom. Waste water from the restroom discharges into an underground septic field. "Is that just a coincidence?" Watts asked. "I think it's very interesting that the slides moved to places where the waste-water system moved." Jerry Wieczorek, civil engineer and researcher with the U.S. Geological Survey National Center in Reston, Va., has published a scientific record of Yosemite Valley's rock falls. His research indicates about half of the 400 rock falls between 1850 and 1992 were influenced by heavy rainfall or other climate-related factors. "There are many possibilities associated with triggering a rock fall - it is not a simple thing to do," he said. The Associated Press contributed to this report.