Clean Up of the Exxon Valdez Spill

By Patrick Shinnefield

In March of 1989 the Exxon Valdez, loaded with 1,264,155 barrels of North Slope crude oil ran aground on Bligh Reef in the northeastern portion of Prince William Sound. About one fifth of the total cargo, 1 1.2 million gallons, spilled into the sea. After three days of calm weather and smooth seas, forceful winds dispersed the oil beyond any hope of containment. Much of the oil was converted into an emulsion of oil and sea water known as mousse. This substance will not bum and is very difficult to remove from the surface of the sea or from shore. The spilled oil, now in the form of thin sheens and thick mousse, continued to spread to the southwest. The oil came ashore along an approximate 750 km (470 miles) trajectory that ran from Prince William Sound to the southern Kodiak Archipelago and Alaska Peninsula. Some scientists estimated that 35% of the spilled oil evaporated, 40% was deposited on beaches within Prince William Sound, and 25% entered the Gulf of Alaska where it either became beached or was lost at sea. Field surveys conducted in the summer of 1989 identified 452 miles of shoreline within Prince William Sound which had been oiled, over 200 miles of which were classified as heavily oiled. In the Kena-Peninsula-Kodiak region, more than 1,000 miles of shoreline were found to be oiled

Work on the spill was divided into three phases: response, damage assessment and restoration. Management of response was an effort coordinated by the U.S. Coast Guard, the Alaska Department of Environmental Conservation and Exxon. Other federal and state agencies and local communities played key roles. Three federal and three state Trustees were made responsible for administering the restoration fund and restoring injured resources and services.

The response effort involved lightering of unspilled cargo, vessel salvage, booming of sensitive areas, beach surveys and assessments, over flights to track the floating oil, skimming of floating oil, cleanup of oiled beaches, wildlife rescue, waste management, logistics support and public relations. Major cleanup operations were conducted during the spring and summer of 1989-1992. Thousands of workers were involved in cleanup and logistics support operations that included hundreds of vessels, aircraft and a substantial land-based infrastructure. In 1989, cleanup efforts involved more than I 1,000 people and 1,400 marine vessels. This multi-year cleanup cost more than two billion dollars. Techniques used to remove or clean oil included: burning, chemical dispersants, high pressure/hot water washing, cold water washing, fertilizer enhanced bioremediation, manual and mechanical removal of oil and oil laden sediments. The oil recovered by skimming operations in 1989 accounted for about 8.5% of the original spill volume. Cleanup operations on the beaches during the first four summers led to the recovery and disposal of approximately 3 1,000 tons of solid oily wastes which were estimated to account for 5 to 8% of the original spill volume. About 90% of the oil in surface beach sediments was removed by natural processes (storm erosion and biodegradation) during winter 89-90, whereas only about 40% of the deeper oil was removed. By 1992, the combination of natural processes and cleanup activities had eliminated nearly all of the surface oil, though small amounts persisted along many shoreline segments in the Sound.

During the first summer after the spill, studies were begun in order to assess the injury inflicted by the spill. Many of these studies were carried out through 1992, costing more than $100 million. Studies were evaluated from five perspectives: (1) immediate injury, (2) long-term alteration of populations , (3) sublethal or latent effects, (4) ecosystem-wide effects, and (5) habitat. These studies formed the scientific basis from which the United States and the State of Alaska would conduct their litigation against Exxon. After the U.S. District Court approved an agreement that settled the claims of the governments for criminal violations and recovery of civil damages, these damage assessment studies would be used to guide restoration. This body of work along with on-going studies provide information on the nature and extent of injury and the status of recovery for an injured resource or service.

The historical crux of the oil spill, with regard to restoration, were the agreements between the State of Alaska and the United States with Exxon, approved by the U.S. District Court on October 8, 1991, on both criminal charges and civil damage claims. This decision eliminated the need for expending millions of dollars and years of time in litigation with Exxon but instead provided money and human resources for restoration work. In the civil settlement, Exxon would pay the State of Alaska and the United States $900 million over a ten year period.

This money would be used for restoration and would be administered by six government Trustees; three federal, three state. Under the criminal plea agreement, Exxon would pay a fine of $250 million. Two criminal restitution funds of $50 million each were established with this money. The two funds are administered separately by the federal and state governments according to guidelines that differ from those that govern the civil settlement fund. Of the remaining $150 million, $125 million was "remitted" or forgiven due to Exxon's cooperation with the governments during the cleanup, timely payment of many private claims, and environmental precautions taken since the spill.

Although there are numerous definitions of the term "restoration" in federal law and in the scientific literature, restoration of Exxon Valdez oil spill-damaged resources must be accomplished according to the definitions of the court order. The rules for spending the civil settlement are provided in a court-approved Memorandum of Agreement between the State of Alaska and the United States. They are as follows:

· Restoration funds must be used ... for the purposes of restoring, replacing, enhancing , or acquiring the equivalent of natural resources injured as a result of the Oil Spill and reduced or lost services provided by such resources...

· Restoration funds must be spent on restoration of natural resources in Alaska unless the Trustees unanimously agree that spending funds outside of the state is necessary for effective restoration.

· All decisions made by the Trustees (such as spending restoration funds) must be made by unanimous consent.

The settlement documents augment these rules with definitions of key terms; these

include: Restore or Restoration means any action, in addition to response and cleanup activities

required or authorized by state or federal law, which endeavors to restore to their pre-spill

condition any natural resource injured, lost, or destroyed as a result of the Oil Spill and the services provided by the resource or which replaces or substitutes for the injured, lost or destroyed resource and affected services. Restoration includes all phases of injury assessment, restoration, replacement and enhancement of natural resources, and acquisition of equivalent resources and services. Replacement or Acquisition of the Equivalent means compensation for

an injured, lost or destroyed resource by substituting another resource that provides the same or substantially similar services as the injured resource.

The strategy for restoration, using the settlement as guidance, was first articulated in the Restoration Framework, Volume 1. This planning document contains criteria used to evaluate the natural resources and services that require restoration. The proposed criteria are based on determinations of. evidence of consequential injury, and adequacy and rate of natural recovery.

The settlement, supplemented by these criteria and definitions, formed the basis for the policies and objectives that were later published in the Restoration Plan and the Environmental Impact Statement. The Restoration Plan includes a program of general restoration, monitoring and research, the establishment of a restoration reserve find and habitat protection and acquisition. Habitat acquisition is the largest part of this program having received overwhelming support from both the scientific community and the public.

The purpose of habitat protection is to identify and protect essential wildlife and fisheries habitats and services and to prevent further environmental damage to resources injured by the Exxon Valdez oil spill. Habitat protection is designed to protect lands linked to resources and services that were injured by the oil spill.

Protection of these lands prevents additional injury to living resources and habitats, services and natural support systems while recovery is taking place. Habitat protection addresses cases where existing regulations affecting private land use are inadequate to protect essential habitats of recovering resources and services. As of the winter of 1997, 484,737 acres of private land or development rights have been purchased and placed into public ownership. These lands have become parks, been incorporated into existing wildlife refuges and are being managed in a manner that will facilitate or enhance recovery of injured resources and services. Negotiations are under way that may lead to similar protection for several hundred thousand acres of land containing habitat important to both affected resources and services and numerous other species.

The Monitoring and Research program, as described in the Restoration Plan, provides information to help guide restoration activities. Each year the Exxon Valdez Oil Spill Trustee Council funds research and monitoring projects. Information from these projects helps to define the status and condition of resources and services: whether they are recovering, whether restoration activities are successful, and what factors may be constraining recovery. Recovery monitoring projects track the rate and degree of recovery of resources and services injured by the spill. They may also determine when recovery has occurred or detect reversals or problems with recovery. Research projects provide information needed to restore an injured resource or service or information about ecosystem relationships.

General restoration includes a wide variety of restoration activities. Most of these activities involve manipulation of the environment; a few may involve funding construction of facilities. General restoration activities include: manipulation of the environment, management of human use, or reduction of marine pollution.

Examples of these projects can be found in any of the annual work plans.

Annual payments by Exxon Corporation to the Restoration Fund end September 2001. To prepare for that time, and to ensure restoration activities which need to be accomplished after that time have a source of funding, the Trustee Council will place a portion of the annual payments into the Restoration Reserve. Details of the operating procedures and status of the Restoration Reserve can be found in the Restoration Plan and Annual Work plans.

The concept of recovery is closely linked to that of injury. If an injured population, habitat or ecosystem can be expected to regain its normal structural and functional attributes within a reasonable period of time, then human intervention should be unnecessary. If natural recovery is not taking place, then restoration may be necessary, if feasible. In the case of injuries from the Exxon Valdez oil spill, both injury and recovery rates have been difficult to estimate for a number of species and habitats. In many cases, baseline data on population status was either inadequate or entirely lacking. Secondly, the health and size of populations differ both temporally and geographically especially in an area as large as that affected by the oil and one with such a high level of natural, biophysical variability. Other confounding factors include sublethal effects and the difficulty of extrapolating the magnitude of injury from carcass counts. Consequently, it is hard to assess either the impact from the spill or natural recovery rates of injured resources and services.

In general, resources and services will have recovered when they return to conditions that would have existed had the spill not occurred. Because it is difficult to predict conditions that would have existed in the absence of the spill, recovery is usually defined as a return to pre-spill conditions or to conditions comparable to those of non-oiled areas. Full ecological recovery will have been achieved when the population of flora and fauna are again present at former or prespill abundances, healthy and productive, and there is a full complement of age classes at the level that would have been present had the spill not occurred. A recovered ecosystem provides the same functions and services as would have been provided had the spill not occurred. Recovery of injured resources, services or natural systems directly attributable to direct restoration efforts has not been documented. Based on results gathered to date, through restoration monitoring studies, it appears that affected systems and their constituent populations may regain normal species composition, diversity, and functional organization through natural successional processes.

Once a spill has occurred in U.S. waters, the responsible company and the Coast Guard's National Response Center notify the federal on-scene response coordinator and state officials. The responsible company activates its response plan and the center ensures that the responsible company is properly carrying out the activities in the plan. The federal on-scene response coordinator may also activate resources if it is determined that more are required or the responsible company is not responding adequately. If the spill is large, the U.S. Departments of Commerce and the Interior may be contacted.

With the approval of the federal on-scene coordinator, chemical cleaning agents can be employed for cleanup. Industry research in this area is continuing to improve the effectiveness of these agents on environmentally sensitive ecosystems.

Generally, the strategy to cleaning up a spill begins with containment, using

containment booms. Booms can be used in several ways: containment booms keep the oil from spreading; collection booms hold the oil near the ship, pier or terminal; Deflection booms steer the oil towards collection areas and away from sensitive areas; and protection booms create barriers that keep oil from affecting sensitive areas. Booms work best in calm waters. Their effectiveness decreases as wave heights and currents increase.

Skimmers are mechanical devices that physically remove the oil from the surface of the water. They can be towed behind a vessel through the oil slick. Vacuum pumps can also be used in cleaning up surface oil quickly.

Sorbents, available as pads, pillows or booms, remove oil sheens and thin slicks that are too scattered for skimming. Made of inert materials, sorbents remove oil either by adsorption (the oil adheres to the surface of the material) or by absorption (the oil penetrates the pores of the material and is trapped inside). In either form water passes through or is repelled by the material.

Chemical dispersants break down oil in water into small droplets. They enhance natural dispersion, accelerating and making the oil more available for natural biodegradation.

Dispersants are not effective for use on all oils. Dispersants are generally used in deep water to better facilitate mixing in the water column and to minimize impact on marine life and the shoreline.

Other chemical countermeasures are used in various ways. Herding agents push or compress surface slicks while emulsion-treating agents impede the formation of, or break down, emulsions of oil and water.

In-situ burning entails corralling and igniting oil contained by a fire-resistant boom. This technique removes 90-95 percent of the oil on the surface of water, but precautions must be taken to protect workers and surrounding areas from the fire and smoke.

Bioremediation of oil on the shoreline uses naturally-occurring bacteria to "eat" oil. Fertilization of this bacteria increases the rate of natural degradation three to four times without harming plants and wildlife. Over the years, extensive research has shown bioremediation can be an effective cleanup technique for environmentally sensitive areas. In recent years, the U.S. Environmental Protection Agency has determined that bioremediation is a safe and effective oil removal option.

The oil industry has joined with government, universities, and other groups in the United States to conduct research and share information about advances in spill prevention and response.

State-of-the-art navigation systems help reduce the risk of accidents and oil spills in U.S. waters. Components include navigational charts, shoreline mapping, global satellite positioning, port navigation, and forecasting water levels and ocean currents.

Computer-aided detection devices have been developed to monitor how vessels react to stress. For example, a stress-monitoring system for vessels determines how hard waves hit the hull, allowing the crew to take corrective action to reduce structural stress. Some of these systems monitor stresses during normal vessel operations, cargo-transferring procedures, and during severe weather conditions.

Risk assessment processes have helped identify the need for new features on vessels, including: improved steering systems; new improved radar detection systems; electronic chart displays; satellite and radio communication; new vessel identification systems such as transponders; and computer monitoring of engine, cargo and hull operations.

Improved countermeasures including dispersants, surface washing agents, surface collecting agents, bioremediation agents and burning agents have been developed and tested extensively. Industry laboratories have developed dispersants that are more effective in treating heavy crude oil over longer periods of time. An oil-weathering model enables oil spill personnel to determine the most opportune times to use dispersants.

The U.S. Department of the Interior's Minerals Management Service is testing prototypes of booms that recover more oil faster. It is also striving to determine the thickness of spills with airborne sensors and remote-sensing devices.