Tank Collapse Releases Fuel into the Monongahela River

When a storage tank owned by Ashland Oil Company collapsed, 3.9 million gallons of diesel fuel were spilled, resulting in one of the worst inland oil spills in U.S. history.

Summary of Event

On Saturday, January 2, 1988, at 5:10 p.m., a storage tank ruptured at the Ashland Oil terminal twenty-five miles southeast of Pittsburgh in Floreffe, Pennsylvania. The rupture released 3.9 million gallons of number 2 diesel oil. The sudden surge of oil spilled over the containment dike, damaged two gasoline tanks on the tank farm, and flowed across a state highway into a ravine. A partially buried culvert allowed oil to return under the highway to a parking area of the Duquesne Light Company adjacent to the tank farm and eventually into a storm sewer leading to the Monongahela River. Disasters;industrial
Ashland Oil Company
Oil spills
Ecological disasters
Monongahela River;oil spill
[kw]Tank Collapse Releases Fuel into the Monongahela River (Jan. 2, 1988)
[kw]Collapse Releases Fuel into the Monongahela River, Tank (Jan. 2, 1988)
[kw]Monongahela River, Tank Collapse Releases Fuel into the (Jan. 2, 1988)
[kw]River, Tank Collapse Releases Fuel into the Monongahela (Jan. 2, 1988)
Ashland Oil Company
Oil spills
Ecological disasters
Monongahela River;oil spill
[g]North America;Jan. 2, 1988: Tank Collapse Releases Fuel into the Monongahela River[06730]
[g]United States;Jan. 2, 1988: Tank Collapse Releases Fuel into the Monongahela River[06730]
[c]Disasters;Jan. 2, 1988: Tank Collapse Releases Fuel into the Monongahela River[06730]
[c]Environmental issues;Jan. 2, 1988: Tank Collapse Releases Fuel into the Monongahela River[06730]
Sasseen, Jerry
Casey, Robert P.
Hall, John R.

Within thirty minutes, 340,000 gallons of diesel fuel were lost into the river, and by morning almost 750,000 gallons of oil flowed through the storm sewer into the Monongahela. Because of the darkness and freezing weather conditions, the extent of the damage to the river and the threat of pollution to water systems downstream on the Monongahela and the Ohio rivers were not fully recognized until Sunday morning, January 3.

After the collapse of the storage tank, employees of Ashland Oil Company immediately notified the U.S. Coast Guard’s National Response Center. By 5:30 p.m., local emergency personnel from the Floreffe Volunteer Fire Department, the borough police, and the Mt. Pleasant Hazardous Materials Team were on-site. The Allegheny County Police Department was notified, and officials there activated the Emergency Operations Center. The Allegheny Health Department and the Pennsylvania Department of Environmental Resources Pennsylvania Department of Environmental Resources (PADER) were notified and arrived at the scene by 6:45 p.m. The Allegheny County Special Interventions Team was notified and arrived by 7:45. At 8:00 p.m., the Pennsylvania Emergency Management Agency (PEMA) was notified.

The immediate concerns of the responding agencies were to assess the situation and to stop the flow of fuel from the site. In the darkness and cold, both these operations were difficult. Furthermore, the strong odor of gasoline indicated a gas leak, but it could not be determined whether the leak had originated in the storage tank holding one million gallons of gasoline or was caused by a damaged gas line. The volatile mixture of gasoline and diesel fuel presented a dangerous situation made even more serious by the presence of hazardous chemicals nearby at the Hercules Chemical Plant. The Duquesne Light Company’s power plant was asked to shut down.

By 11:00 p.m., five leaks had been found in the damaged gasoline tank. Four of the leaks were successfully plugged, but the emergency team was unable to plug the leak from the tank’s feeder line. Meanwhile, the crew members at the river site decided that the river’s current was too rapid and the oil’s flow was too fast for them to set up booms to contain the spill.

After midnight, the decision was made to evacuate twelve hundred nearby residents. Throughout the night, emergency crews and firefighters worked to contain the oil and prevent spilled oil from flowing into the sewer system. A plug was positioned over the sewer’s river accessway; oil began to rise in a manhole near the power plant. To prevent oil from flowing over into the area of the power plant, which had resumed operation, the team had to remove the plug on the river end of the sewer line.

The next morning, the on-scene coordinator for the Environmental Protection Agency (EPA), Jerry Sasseen, arrived. By 9:30 a.m., Ashland employees had off-loaded the gasoline from the damaged tank onto barges. A vacuum truck had arrived to draw oil from the storm sewer, and the flow into the river was stopped. By noon, the evacuation order was lifted.

The situation at the river was found to be worse than expected. The oil had dispersed through the water column and had not remained on the surface. As the water flowed over the first lock in the river within minutes of the spill, the oil was further emulsified. Water companies downstream were notified, and intakes of water by communities along the Monongahela and Ohio rivers were sequentially shut off. Water;pollution Connections among the various community water supplies had to be planned, and National Guard water trailers were brought in.

The dispersion of oil to a depth of 16 feet meant that surface recovery of oil from the river would be very difficult. Ten miles downstream, oil had spanned the width of the river. Containment booms that had been placed downstream early in the morning had little effect, so deflection booms were used to deflect surface oil to natural collection areas. Because of the frigid temperatures, the oil formed heavy globs that could be picked up from the edges of the river and from the river bottom. Over a period of two months, nearly 29 percent of the fuel that flowed into the river, or 205,000 gallons of oil, was recovered.

Damage to wildlife was difficult to assess because of the season. Many animals were hibernating; plants were dormant and fish were inactive. The PADER, however, estimated that eleven thousand fish and two thousand waterfowl died. Volunteers and experts from Tri-State Bird Rescue and Research, Incorporated, and game commission officials saved about seventy-eight waterfowl by cleaning them. Studies were begun to determine the effects of the spill on fish and on an endangered mussel species in the Ohio River, the pink pearly mucket.

Investigations into the reason for the tank collapse began immediately. The tank had been relocated from an Ashland Oil facility in Cleveland, Ohio, through a contract with the Skinner Tank Company. It had been disassembled in Cleveland, and a new foundation had been built for it in Floreffe, with reassembled steel sheets. The tank was filled with oil to a peak level of nearly forty-six feet for the first time minutes before it collapsed.

Ashland hired Battelle Memorial Institute, Battelle Memorial Institute a technological research organization, to investigate the cause of the collapse. Battelle’s findings were released in May, 1988. A flaw the size of a dime was found in the steel plates at the base of the tank, close to a weld. The steel, forty years old and of a less durable quality than was available at the time of the incident, was weakened by the new welds when the tank was reassembled. The winter temperature was such that a brittle fracture could occur, and stress resulting from the filling of the tank was sufficient to initiate a crack near a weld.

Ashland had not secured a written permit before constructing the tank; instead, it had relied on a verbal approval given in conversation. The tank was not properly tested before it was filled, and X rays of the welds were not complete; weld defects that were found were not corrected. It is possible that X rays could have detected the defect, which was present at the time of the tank’s use in Cleveland.


The Ashland Oil spill was the worst inland oil spill in U.S. history. The cold temperatures, the turbidity and high level of the water, and the rapid current in the Monongahela River as a result of previous heavy rainfall made assessment of the situation and early cleanup work difficult. Most observers, however, have noted that the situation could have been much worse than it was. The most serious dangers at first apparent to the emergency workers were those of fire, explosion, and dispersion of extremely hazardous chemicals resulting from the leakage of gasoline.

Emergency workers successfully resolved the threat of contamination to water supplies in the surrounding communities. Intakes at water companies in three states were sequentially shut off in time so that permanent damage to water sources was prevented. Nearly 25,000 persons were without water for up to eight days, and more than 750,000 people were asked to conserve water under penalty of a $200 fine. Here, the role of the news media was critically important. Emergency personnel provided water to those in need of it and ensured that hospitals and nursing homes with steam or hot-water heat sources were safe. Analysts agree that the agencies, individuals, volunteer groups, and Ashland Oil cooperated successfully in protecting the public health throughout the emergency.

Under the Clean Water Act, Clean Water Act (1972) the EPA had been given authority to regulate aboveground tanks, but there were serious gaps in the regulations regarding monitoring of the tanks. At the federal level, stronger legislation was proposed to ensure that such a spill would not occur again. Both houses of the U.S. Congress conducted hearings regarding new legislation, and requirements for design, siting, construction, testing, and maintenance of oil tanks were subsequently strengthened. In addition, new legislation required the establishment of a spill containment system and emergency plans in the event of a spill, along with regular inspection by the EPA and contracted agencies.

At the state level, Pennsylvania governor Robert P. Casey appointed an investigative committee to determine the cause of the disaster. Preliminary studies showed that, of the sixty-five hundred aboveground storage tanks in the state, many were substandard and their owners were without safety plans.

Ashland Oil conducted internal studies, and, as a result of the Floreffe episode, the company inspected all of its tanks. Ashland was required to pay a federal criminal fine of $2.25 million for violating two environmental laws, the federal Refuse Act and the Clean Water Act. The company paid $11 million in cleanup costs and $30 million to various parties. The money was used in part to settle lawsuits brought by parties who, because of water shutoff, lost wages or had interrupted business. It also compensated the states of Pennsylvania, Ohio, and West Virginia for damages to resources. The settlement fine that was given to the three states for damage to natural resources was used to study the effect of the oil spill on river ecosystems over a period of five to six years. These studies, carried out under the joint direction of the PADER and the Ohio River Sanitary Commission, included groundwater analysis and wildlife studies.

The complexity of the Ashland Oil incident highlighted the importance of careful local emergency planning. Emergency planning The first to arrive at the scene were local emergency officials, then county, then state, and, finally, federal officials. Each agency knew its role and responsibility, but the intergovernment agreements and relationships were unclear. There was some confusion as to who had decision-making authority, who could act independently, and who had to be consulted. For example, it was not clear who had the authority to order the water supply opened and closed. Such confusion caused delays in response times and action.

A study of the emergency response procedures and the reactions of the workers and community members was conducted by faculty at the University of Pittsburgh Center for Social and Urban Research. In addition, two studies were completed under the direction of Jeanette Trauth Trauth, Jeanette of the Graduate School of Public Health at the University of Pittsburgh. These studies resulted in recommendations regarding emergency response plans for communities with facilities that handle hazardous materials.

The disastrous oil spill of 1988 set back ten years of successful efforts to clean up the Monongahela River. Most of the previous experience and technology regarding oil spills was applicable to oceans and lakes, not to fast-moving streams. The collapse of the storage tank and the subsequent contamination of the river by diesel fuel led to new requirements for spill containment and emergency procedures as well as to regular safety inspections by EPA officials. Disasters;industrial
Ashland Oil Company
Oil spills
Ecological disasters
Monongahela River;oil spill

Further Reading

  • Burger, Joanna. Oil Spills. New Brunswick, N.J.: Rutgers University Press, 1997. Comprehensive volume includes an overview of the history of oil spills as well as discussion of their impacts—legal, economic, social, and ecological. Also examines the efficacy of cleanup efforts.
  • Germann, Ray. “Oil Spill on the Monongahela: As the Story Unfolded.” EPA Journal 14 (April, 1988): 35-37. Presents a summary of the Ashland Oil spill episode from the viewpoint of the EPA public relations office.
  • Gibson, Michael M. Environmental Regulation of Petroleum Spills and Wastes. New York: John Wiley & Sons, 1993. Excellent resource provides a basic, comprehensive treatment of the complex legal issues related to oil spills and analyzes the roles of regulatory agencies in dealing with such events. Written from a practical historical perspective.
  • Newton, Lisa H., and Catherine K. Dillingham. Watersheds 2: Ten Cases in Environmental Ethics. 2d ed. Belmont, Calif.: Wadsworth, 1996. Underscores the biological, economic, and legal issues involved in resolving technological impact on the environment. Chapter 6 discusses the Exxon Valdez oil spill, a particularly interesting case involving corporate responsibility and environmental policy making.
  • Pennsylvania Emergency Management Agency. After Action Report: Ashland Oil Spill, January 2, 1988. Harrisburg: Author, 1989. Reconstructs how local, state, and federal agencies, as well as the news media and the community, responded to the emergency. Identifies impediments to rapid disaster response.
  • U.S. Congress. House Committee on Merchant Marine and Fisheries. Subcommittee on Oversight and Investigations. Monongahela River Oil Spill: Hearings Before the Subcommittee on Oversight and Investigations of the Committee on Merchant Marine and Fisheries, House of Representatives, on the Effects of the Oil Spill in Floreffe, Pennsylvania, on the Environment and Lives of Those in the Area, and to Design a Policy Which Will Protect This Nation’s Environmental Resources. 100th Congress, 2d session, 1988.
  • U.S. Congress. Senate Committee on Environment and Public Works. Subcommittee on Environmental Protection. Oil Spill on the Monongahela and Ohio Rivers: Hearing Before the Subcommittee on Environmental Protection of the Committee on Environment and Public Works, United States Senate. 100th Congress, 2d session, 1988. Transcripts of the hearings provide basic information on the oil spill incident and on considerations for the design of new legislation. The Senate hearings volume also includes the Battelle Memorial Institute Report on the cause of the tank collapse.
  • Wolfson, Elissa. “Crude Awakening in Ecuador.” E: The Environmental Magazine, August, 1994, 13-14. Briefly describes the devastating effects of oil spills by U.S.-based companies on rivers and wildlife in Ecuador.

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