Pat Pine, general manager of the Las Vegas Valley Water District, says undetermined amounts of raw sewage were dumped into Lake Mead when an earthen dam broke early on New Year's Day near St. George.

Pine estimates 250,000 of untreated sewage was released when a sewer line broke in the Bloomington Hills subdivision. The line was located under the Virgin River, which flows into Lake Mead.Lake Mead supplies most of the Las Vegas Valley drinking water. While there probably will be no effect on water quality, officials are monitoring it.