Alaska's Mount Redoubt volcano began erupting on March 22, 2009, and activity continued for several months. During the eruptions, which lasted for several months, reports found ash clouds reaching as high as above sea level. In response, the National Weather Service issued a series of ash fall advisories. The Mat-Su Valley, Anchorage, Valdez and large portions of the Kenai Peninsula all received coatings of tephra. The 2009 eruptions of Mount Redoubt represented the most seismic activity occurring on the mountain in twenty years. Renewed concerns over the Drift River Terminal Facility The 2009 eruptions of Mount Redoubt renewed concerns over the safety of the nearby tank farm which holds crude oil, known as the Drift River Terminal Facility. During the earlier, 1989-90 eruptions of Redoubt, the facility was inundated and damaged by lahars. Dikes built after the 89/90 activity protected the tanks, although an aircraft hangar and runway were flooded and damaged by the flooding and related debris. In late March the US Coast Guard decided to move the millions of gallons located at the facility to prevent an ecological disaster. The plan called for then refilling the tanks with "harmless" ballast water to prevent them from being dislodged by flooding.. However, on April 5, the Coast Guard stated that filling the empty tanks with ballast water was not possible, because it would create a hazardous waste that the neither the facility nor the Coast Guard was prepared to deal with afterward. Instead, the oil was removed and the empty tanks remained vulnerable to damage from further flooding. In the meantime, oil production in Cook Inlet was suspended, because the tank farms were out of commission while Mount Redoubt remained in an eruptive state. When the eruptions subsided, the tanks were undamaged and the facility was cleared of debris and subsequently reopened. Eruptive activity As of April 4, 2009, AVO had recorded twenty-six volcanic eruptions and/or explosions at Redoubt volcano, although they singled out nineteen of them as most notable. The AVO refers to an "eruption" as any event which discharges ash into the atmosphere, while adding the term "explosion" for more vigorous events. The AVO did not rate and compare each eruption, although the 9:24 am eruption on March 26 reached an altitude of 65,000 feet making it the highest volcanic ash cloud to date during the 2009 phase of activity. The eruption on April 4 was described as