To understand the risks of oil industry operations to Cook Inlet’s environment, it’s important to know which activities pose the greatest threats and what can be impacted. Oil exploration, development, and production activities in Cook Inlet known to jeopardize the environment range from permitted contaminant discharges such as produced water, drilling muds and cuttings; oil spills from vessels, blowouts, or leaking pipelines; and noise from exploration, development, or production activities. Additionally, natural processes can magnify the dangers. This section discusses the greatest threats to Cook Inlet, and highlights the importance of the Cook Inlet Navigational Risk Assessment for identifying options to reduce those risks.
CIRCAC provides data and advice to help managers and responders make better decisions about the acceptability of risks of oil production and transportation in our area of concern; we recommend, develop and promote measures to mitigate those risks. Following years of declining industry activity, lower Cook Inlet is facing potential new pressure from planned federal lease sales necessitating work to assess unique habitats.
Cook Inlet’s tides are some of the most extreme in the world and the massive volumes of water moving in and out of the Inlet produce dangerous tidal currents. The moving water interacts through friction with the shape of the Inlet’s seafloor and creates unique convergence zones known as “tide rips” that can collect debris and ice.
Propelled by tidal currents and wind, Cook Inlet sea ice represents one of the greatest dangers to navigation and marine structures. This mobile ice can have a substantial impact on human activities and impede vessel transits. Instances where sea ice played a role in tanker accidents are well documented. In February 1999, moving ice pushed the Ocean Laurel into Unocal’s dock at Nikiski, damaging the dock and catwalk. A week later, the Chesapeake Trader was damaged and spilled 420 gallons of crude oil after colliding with a heavy ice floe. In 2002, sea ice pinned the Monarch to a Cook Inlet platform; she subsequently sank. Ice also played a role when the Seabulk Pride broke away from its moorings at the Nikiski dock and grounded off of East Forelands in 2006.
There are four active volcanoes in the region, Mount Augustine, Mount Iliamna, Mount Redoubt and Mount Spur which pose risks to oil industry operations in the Inlet. During the eruption of Mt. Redoubt in 2009, the Drift River Oil Terminal tank farm was taken out of commission and Cook Inlet oil production temporarily suspended when lahars (mud and debris flows) from the volcano inundated the Drift River valley. Ultimately, containment berms protected the tanks themselves, but required extensive reinforcement for future protection. CIRCAC has since adopted a position: the preferred long-term option is to replace the terminal and its associated tankers with a subsea crude oil transmission pipeline to transport oil from west side production operations to the refinery on the east side of Cook Inlet. While recognizing that undersea pipelines also pose risks of oil spills to Cook Inlet, our opinion is that they are less than those posed by storing oil in tanks or loading oil onto tankers at this facility.