EPA Publication Number: EPA 550-R-96-002

Published: September 1996

This document was prepared with support of USEPA Order Number 6W-4075-TASA, by the National Institute for Chemical Studies, August, 1996

For: Chemical Emergency Preparedness and Prevention Office, Office of Solid Waste and Emergency Response, U.S. Environmental Protection Agency, Washington, DC 20460

FOREWORD

This document presents the comments and recommendations of five expert independent reviewers, with whom EPA contracted to examine an EPA Chemical Accident Investigation Report, "Terra Industries, Inc. Nitrogen Fertilizer Facility, Port Neal, Iowa." The EPA investigation report was written by an investigation team at its Region VII office in Kansas City and published in January 1996.

The Clean Air Act Amendments of 1990, Section 112(r), mandated the creation of an independent Chemical Safety and Hazard Investigation Board (CSHIB) to investigate chemical accidents and recommend steps to reduce the risk and hazards of chemical releases. However, the CSHIB was never formed. In January 1995, the Administration asked EPA and OSHA, under their own existing authorities, to investigate chemical accidents and issue public reports containing recommendations on what the government, industry, and other stakeholders could do to prevent similar accidents from occurring in the future. The EPA Terra Industries Investigation Report is the first such report, dealing with a chemical accident in Port Neal, Iowa in December, 1994. Since Iowa is one of 23 States having an OSHA State Plan, the federal OSHA was not a joint investigator with EPA in this case.

In the spring and summer, 1996, EPA assembled a group of experts, charging them to examine the scope, approaches, and methods of this first report to guide future studies and investigations. Dr. Paul Hill of the National Institute for Chemical Studies served as Chair of the review group.

The five reviewers independently examined the EPA report, documenting their analyses in written comments. The Chair then circulated all comments to all reviewers, and convened a meeting of the reviewers at EPA's regional offices in Kansas City to enable them to share their comments from their different perspectives, to question the authors of the report, and to examine photographs and other available documents. The Chair then wrote a summary of the meeting and recommendations of the reviewers. This document includes copies of the reviewers' comments, the Chair's summary, EPA's charge to the reviewers, and EPA's reply to the reviewers' recommendations.

Expert Review: Chair's Report

A REVIEW OF USEPA'S CHEMICAL ACCIDENT INVESTIGATION REPORT: TERRA INDUSTRIES, INC., NITROGEN FERTILIZER FACILITY, PORT NEAL, IOWA

REVIEWERS

DR. ISADORE (IRV) ROSENTHAL

The Wharton School of Decision and Risk

University of Pennsylvania

MR. JOEL R. VARIAN

International Association of Machinists and Aerospace Workers

AFL-CIO (Retired)

MS. PAMELA NIXON, MS.,MT.

CMA Public Advisory Committee

DR. GERALDINE V. COX

AMPOTECH

AMPOTECH Poland

DR. PAUL L. HILL (Chairman)

NICS

EXECUTIVE SUMMARY

The NICS and Dr. Paul L. Hill, in conjunction with, Drs. Irv Rosenthal and Geraldine Cox, Ms. Pamela Nixon and Mr. Joel Varian, were requested to conduct independent reviews of EPA's investigative report on Terra Industries 1994 accident. In order to improve future reports as well as future efforts to systematically collect data at accident sites, the review team offers the following major recommendations for consideration:

EPA should:

Include time lines in future reports. Expand and continue to model the scenario-by-scenario approach. Adopt or specify rigorous technical procedures sanctioned by the engineering and research communities. Develop a defined protocol for accident investigations. Hold public meetings to seek stakeholders' input on the protocol. Consider accident oversight committees at affected sites which include public liaisons. Initiate agreements with other federal, state, and local entities with accident response authorities or consider legislative recommendations to accomplish same. Create increased public and private awareness of it's investigative program. Clearly articulate the national goals and criteria for accident investigation. Draw upon the existing experience of NTSB and other agencies for assistance in the evolving program.

Industry should:

Take note and seriously address EPA's January 23, 1996 recommendations for accident prevention. Initiate greater awareness of process safety regarding ammonium nitrate through the research and engineering communities. Proactively embrace mechanisms for accident prevention.

States and Communities should:

Initiate dialogue with industry and EPA to construct effective protocols. Consider agreements for resource and authority coordination.

BACKGROUND AND STATEMENT OF PURPOSE

At approximately 0606 hours on December 13, 1994, an explosion occurred in the ammonium nitrate plant at the Terra International, Inc., Port Neal Complex. Four persons were killed as a direct result of the explosion, and 18 were injured and required hospitalization. The explosion resulted in the release of approximately 5,700 tons of anhydrous ammonia to the air and secondary containment, approximately 25,000 gallons of nitric acid to the ground and lined chemical ditches and sumps, and a large volume of liquid ammonium nitrate solution into secondary containment. Off site ammonia releases continued for approximately six days following the explosion and drifted several miles. Chemicals released as a result of the explosion have resulted in extensive environmental contamination including groundwater under the facility.

The U. S. Environmental Protection Agency (EPA) Region VII was directed by EPA Headquarters to conduct an investigation to determine the cause of the explosion and to develop recommendations that would help prevent similar occurrences in ammonium nitrate production facilities in the future. A report released by the Agency on January 23, 1996 contains conclusions reached by the EPA chemical accident investigation team regarding the cause of the explosion at the Terra International, Inc., Port Neal Complex and recommendations for prevention of future similar occurrences. The investigation team from EPA was led by On-Scene coordinator (OSC) Mark Thomas, Ph.D. of the Region VII Office with additional assistance defined in the report.

Shortly after the issuance of the report, EPA Headquarters initiated discussions with the National Institute for Chemical Studies (NICS) to develop an independent review of EPA's investigation and findings. As an independent non-profit organization with environmental, industry, labor and community advocate constituents, NICS has a reputation for objective reports on chemical accident prevention and preparedness. On March 5, 1996, EPA reached agreement with NICS to oversee the review and designate Dr. Paul L. Hill as chairman of a proposed panel of individuals who would conduct the review. Panelists were selected on the basis of their expertise in processengineering, chemical safety, previous accident reviews and management disciplines as well as their broad representation of different stakeholder perspectives. NICS developed a slate of potential reviewers and provided the list to the Agency who selected and contracted with four (4) individuals in addition to Dr. Hill. Reviewers were not asked or retained to conduct independent research in order to supplement their technical knowledge and professional judgement or to verify the technical information contained in the EPA Terra Industries Report. Reviewers and their affiliations are listed on the previous page.

Among the charges of the Chairman were to provide copies of the report to the reviewers, solicit their written comments on the report, develop his own critique, distribute all five (5) commentaries to each of the participants as well as EPA, organize a meeting to discuss their reviews, chair the meeting and provide a final report of collective findings and recommendations to the Agency. After the receipt of individual, initial comments in July, 1996, the Chairman called a meeting on July 28-30, 1996 at the EPA Regional Office in Kansas City, Kansas. The review meeting was attended by all five (5) members of the panel as well as EPA staff. (See Appendix 1).

The purpose of this meeting was not to form consensus on the issues of causality or absolute recommendations to the agency. Rather, it was a forum to exchange ideas about the report's findings and probe the records and recorded testimony for additional clarifications. Agency staff were present by request of the Chairman to respond to questions and provide details of data collection, procedure and scenario development used to compile the report. The charge of the review panel members was quite narrow: (a) to assess the plausibility of the report findings based on all evidence collected by the agency and (b) to make recommendations on procedure, technique and report formulation which would improve future Agency accident investigation products.

The review team considered only the immediate information surrounding EPA's report. While the team was aware of additional reports and documents developed by other parties, these were not considered germane to the limited charge given by the Agency. In the possession of reviewers was: (a) the settlement agreement between Terra International, Inc. and Iowa OSHA Employment Appeal Board and (b) the Terra Port Neal Explosion report dated July 17, 1995 issued by a group of outside experts retained by the General Counsel of Terra Industries, Inc. Technical and legal assertions raised by the other parties involved in the Terra Industries, Inc. accident fell clearly outside the scope of the review team's charge. No opinions are surmised or offered on these issues.

Accident investigations and the attempt to reconstruct conditions which lead to an accident are inherently difficult to pursue. The current report indicates that certain evidence, diagrams, and requested documents were either destroyed or unavailable for this investigation report. Even with satisfactory provision of existing management, operations and training materials, reliance upon human knowledge and recollections as well as potential nondisclosure makes the job of accident investigation for root cause all the more difficult. In light of the Clean Air Act Amendments of 1990, the review team recognizes that as a nation, significant insights of investigation, and review, must be assessed to fully implement the Act.

During the review meeting held in Kansas City, the review team had unlimited access to numerous photographs, drawings, analyses, transcripts and other evidence and documentation collected by the Agency for development of the report. The team did not speak with any employee of Terra International, Inc. and did not visit the accident site in Port Neal, Iowa. While a broader investigation would have logically involved greater efforts to carry out these activities, this review was limited to the January 23, 1996 report and the in-house information cited above. To more clearly define the limited scope of this investigation report review, an outline of the key questions addressed by the team are as follows. Reviewers were asked to:

a. Comment on the technical soundness.

b. Comment on the approach scenario by scenario.

c. Comment on the findings of the report and the most plausible scenario.

d. Comment on the comprehensiveness and reasonableness of the technical conditions under which the accident occurred.

e. Are specific roles of certain equipment appropriately considered?

f. Is the discussion of ammonium nitrate (AN) appropriate?

g. Were all external factors considered in a proper way?

h. Comment on the overall conclusions and recommendations.

i. What activities or report components should be modeled for future investigations?

j. Were prevention recommendations appropriately presented?

k. Were the roles of other entities appropriately addressed?

l. Are there additional recommendations for actions that could have been or should be taken in the future?

After providing initial comments and after meeting for a total of more than 18 hours, the review team provided a series of comments about the report for the agency's consideration. These comments, again, do not represent any absolute consensus of the team, in that many individual stakeholder perspectives are included. However, the team was unanimous in its support that all pertinent comments be offered to the Agency. In addition to individual comments provided by the reviewers (which are included in Appendix 2 of this report), team commentary on the basic issue questions cited above are intended to provide a constructive critique. Follow-up comments were provided by two members of the team (See Appendix III).

APPROACH

Generally the team considered the overall approach to the report to be sound and appropriate. The text was straight forward and lacked overly technical jargon which was considered beneficial for public policy makers and the general public. Both constituent groups have expressed keen interest in this report and it seems to be sensitive to these broad audiences. The "scenario by scenario" approach used in the report is a valid and useful approach which was also viewed as helpful to the reader.

In response to the question of whether this was the "correct" approach, this becomes a philosophical discussion of the technical community on process safety and investigations. There exists a vast literature on approaches to accident investigation as evidenced by a recent publication by the Center for Chemical Process Safety (CCPS) of the American Institute of Chemical Engineers called "Guidelines for Investigating Chemical Processing Incidents." While this document and others describe numerous `accepted' approaches for accident investigation such as the one at Terra, the key point of the review team was that a referenced, accepted methodology be utilized and clearly described by the report (and future reports). After meeting with the OSC and others involved in the investigation in Kansas City, it became apparent that several methodologies were considered. To the reader of the report, and there are many, it is not readily apparent that such were utilized for this investigation. All reports in the future should specify the process, procedure or guidelines within which the investigation team was operating.

While the team viewed the "scenario by scenario" approach as useful and informative, it was incomplete. Team members understood the need to truncate activities into a readable and concise document. However, the omission of the range of scenarios (including sabotage) and why these were dismissed should always be stated. Without questioning the investigators, reviewers had no indication whether all scenarios had been considered and why/how same were dismissed.

The scenarios presented did a good job of systematically narrowing the scope of possibilities for root cause based on evidence and good science. The use of a metallurgist was particularly helpful. The overall findings of the report based on these scenarios and the evidence presented seem reasonable to the entire review team. Given that Terra International, Inc. has presented a report with slightly different findings relating to one piece of equipment (the sparger), this scenario could have been pursued in greater detail (see sparger discussion).

PLAUSIBILITY OF EPA CONCLUSIONS

Overall, the team agreed that EPA's conclusions were plausible given the evidence collected and presented. It must be noted however that some evidence, samples and data were either destroyed or never collected due to conditions under which the investigation took place. Lack of clear control and coordination at the site seem to be primarily responsible for this. As the final report conclusions indicate, several conditions at the plant were outside the range of standard or safe operating procedures and parameters and led to this tragic accident.

The only reservation raised by the reviewers dealt with the issue of the sparger. The committee was unable to come to consensus on the role the sparger did or did not play in the overall stimulus of the explosion of the neutralizer. This single uncertainty however, does not negate the reasonableness of the six conclusions put forward by EPA. There is significant evidence that numerous problems existed at the facility. The review team's only concern with EPA's major conclusions are of definition. That is, the conclusions themselves are less explanatory of "root cause" than is the body of the report discussion. Since root causes are "prime reasons which lead to an unsafe act or unsafe condition or constitute an underlying condition and result in an accident; if the condition is removed the particular incident would not have occurred." Given this definition, the management system failures that led to or allowed the existence of the unsafe acts or unsafe conditions that the report concludes caused the accident was less than adequate. The report discussion does a better job of identifying these causes than do the conclusion and recommendation sections of the report. Attention to the relationships between root cause and conclusions reached would assist future readers and future reports.

COMPLETENESS

The team agreed that the investigators made a concerted effort to provide complete information and analyses. Reviewers recognized that investigators were somewhat challenged by the circumstances of cooperation, authority and coordination at the site. Given the conditions at the Port Neal facility both before and after the December 13, 1994 explosion, the investigators did a thorough job. While the review team initially raised questions regarding various technical issues (for instance, sampling, sources of contamination of ammonium nitrate stocks and inert coatings of vessels) these were sufficiently answered by the OSC and members of the investigation staff.

DISCUSSION OF CONDITIONS

Though historical records are not overly extensive on ammonium nitrate explosions, the report discussion of pre-incident conditions was both valuable and thorough. This discussion helped to establish the plausibility of certain scenario building exercises which were undertaken by the investigators. It also added value to the basis of discussion for non-technical stakeholders who have or are likely to review the report. This type of background search on basic chemistry and literature should be included in future reports.

EXTERNAL ENTITIES AND FACTORS

Given that a clear lack of coordination with other agencies and interests existed during this investigation, the report does not deal adequately with external factors. Only upon interview with agency personnel was it apparent to the reviewers just how difficult this issue was. Because Iowa is a designated "state OSHA" by its parent federal agency, coordination and, therefore, consideration of more complete information exchange was greatly lacking. If detailed, coordinated investigations and joint reports are to be achieved as intended by the CAAA of 1990, a broad protocol, comprehensive in nature and definitive of the roles of all stakeholders must be developed. State agencies, local response organizations, industry, labor and community advocates should be coordinated by federal agencies into a cohesive, informed and collaborative effort. Externally, an interface with all stakeholders would ensure accurate information is presented for public consumption. Due to circumstances surrounding this particular report, these significant issues were not addressed.

ADDITIONAL ACTIONS

In its release of the report on January 23, 1996, EPA made several recommendations based on its findings during the investigation. These ranged from recommending thorough process hazards analyses, to reviews of safe operating procedures and increased emphasis on training, communication and preventive maintenance. The review team supports these recommendations and notes that many are now contained in OSHA and/or EPA regulations. From this incident, facility management must recognize the value and meaning of compliance with existing rules and overall safe management practices.

EPA should follow up with both the research community, trade associations and all ammonium nitrate producers to fully inform them of the findings of this report. Additional research, if properly structured should address ammonium nitrate sensitivity, confinement and activation. Also, the emergency response community should be provided with detailed reviews of this accident and how responders should prepare for responses to similar incidents.

KEY ISSUES

Upon discussion the review team attempted to focus on key issues for EPA's consideration. Key issues are a 'global' view of not only this accident review but also those which will follow as the Agency's process and program for accident investigation matures. In the view of the entire team, the following critical issues should be addressed:

In real terms, what were EPA's strategic goals for this investigation? Others?

What will be the criteria for future investigations? Criteria should reflect defined agency goals?

What should the overall process and procedure include? Should a uniform accident protocol be vetted by all stakeholders?

What resources should be kept on hand for future investigations? Contract resources? National plan for mobilization?

What should be ideal timing of investigations?

What should be the roles of other agencies?

What internal (EPA) coordination should occur vis-a-vis other programs?

Should legislative changes be pursued to achieve greater coordination? Could formal interagency agreements achieve the same goal?

How should the agency use accident reports to leverage industry actions?

How can industry be involved?

What other federal experiences (e.g. NTSB) can the agency draw upon to craft a coordinated response?

What activities can be undertaken to increase awareness of protocols or anticipated federal response to future accidents?

For some of these questions, the review team tried to make recommendations based on their own experience and expertise. Others fell clearly outside the team's purview and are left to the agency's consideration.

RECOMMENDATIONS

The Accident Report Review Team recommends that EPA assess its objectives and clearly articulate a strategy to be commented upon by the various stakeholders. Major problems observed in the Port Neal, Iowa investigation were (a) lack of understanding that EPA had authority to conduct the investigation and (b) lack of coordination with other parties who also had interests or authorities to collect information. These two issues precipitated most other deficiencies found in both the investigation and the written report. Lack of clear authority and direction were the greatest hindrances to EPA's staff.

The Team's recommendation for a uniform accident investigation policy should allow for consideration of the numerous stakeholders including the public. Although the latter would not be directly involved in evidence collection and technical work, the concept of an oversight committee which includes public representation should be considered. Those parties or agencies with existing authorities should be organized, through agreements or statutory changes, into a structured, mutually beneficial approach. Recognized is the fact that EPA could be executing agreements with 50 states plus countless local entities. In the Terra incident, a local fire chief, acting on his independent authority, destroyed evidence by "hosing down" the area shortly after the event. Such seemingly random actions will continue to occur at accident sites until a uniform protocol is issued.

Timing should be addressed also, as the agency's response did not begin until six days after the event. While stabilization of the site was necessary and time consuming, the OSC was required to develop an investigation strategy and implement that strategy impromptu. By this time, weather, movement of debris, loss or destruction of evidence (e.g. the pry bar opening of 416J pump by Terra personnel) or the actions of other agencies (e.g.. fire department) had degraded or eliminated potentially critical evidence. The initial resistance of Terra personnel to take seriously the EPA investigation team as demonstrated by the 26 site visits also slowed the initiation and completion time of the investigation.

EPA should consider a national network of response capabilities and expertise as its accident investigation program matures. In an effort to reduce costs, personnel or contract services with particular expertise could be integrated into an overall approach at the direction of Headquarters or among the Regional Offices. The previous recommendations regarding the expertise of other agencies including OSHA, states, etc. should also be integrated into this potential network.

EPA should consider how it might leverage industry response to this and future reports. Clearly, other ammonium nitrate producers will review this report for its implications on their operations. However, other mechanisms such as working with trade associations or specific groups like AICHE's CCPS, the Ammonia Institute, and others may provide a comprehensive yet focused approach.

Due to the nature of several key issues raised by the review team as well as the limited time in which they had to consider the report, numerous issues remain unaddressed. The Agency should continue to deal with these over time by seeking additional internal and external expertise on several key subjects. Given the circumstances, EPA and particularly Mark Thomas of Region VII, have made a valuable contribution to the Agency's evolving investigative process. While inclusion of analytical protocols, time lines and additional data may have improved EPA's Terra Industries report, the content provides plausible support of the agency's conclusions and actions. Given the nature of industrial facilities which handle hazardous materials and existing regulatory requirements, numerous deficiencies surfaced at Terra's Port Neal operation. Based on the agency's evidence and the report, an array of management, equipment, training and safety parameters were pushed beyond their safe operating range. When this occurs, disastrous consequences are the result.

EPA response to expert review recommendations

EPA RESPONSE TO EXPERT REVIEW OF EPA INVESTIGATIVE REPORT ON TERRA

RECOMMENDATION: EPA should include time lines in future reports.

REPLY: EPA agrees that this element would enhance future reports and is explicitly including it in the EPA/OSHA joint protocol on investigations, now being prepared.

RECOMMENDATION: EPA should expand and continue to model the scenario-by-scenario approach.

REPLY: EPA has included this as well in the proposed protocol. We would expect that the approach will become more and more refined as the program matures. This is a valuable tool for those investigations when this approach is appropriate. Reports should include a full discussion of scenarios discarded as well as considered.

RECOMMENDATION: EPA should adopt or specify rigorous technical procedures sanctioned by the engineering and research communities.

REPLY: EPA is aware of the available established methodologies for accident investigation. Its investigators will receive training on several of these procedures. The EPA investigation team will choose one or more of these procedures for a given investigation and will describe the investigative methodology in its report.

RECOMMENDATION: EPA should develop a refined protocol for accident investigations.

REPLY: EPA agrees that such a protocol is necessary and has been developing a joint protocol with OSHA during the past year. This protocol defines the purpose and goal of investigations; spells out cooperation among EPA, OSHA, local investigators, and local stakeholders; includes discussion of technical approaches and procedures for conducting various elements of investigations; addresses protection of confidential business information; and addresses production of the accident report and alerts which may stem from information gathered during the investigation. This will be a public document which will inform all of the investigative program.

RECOMMENDATION: EPA should hold public meetings to seek stakeholders' input on the protocol.

REPLY: EPA plans to share the proposed protocol with stakeholders who will be potentially affected by investigations conducted according to its directives. To obtain these comments, we will make the draft protocol available through electronic and other means and will consider actions such as holding a public meeting as recommended. We expect that the protocol will be revised periodically as needed.

RECOMMENDATIONS: EPA should consider accident oversight committees at affected sites which include public liaisons.

REPLY: EPA agrees that vehicles should be available for public input into and communication with the review team. Existing elements such as Local Emergency Planning Committees could serve this function.

RECOMMENDATION: EPA should initiate agreements with other federal, state, and local entities with accident response authorities or consider legislative recommendations to accomplish same.

REPLY: We agree such agreements are essential. EPA and OSHA have been developing a Memorandum of Understanding to set forth terms of cooperation and coordination between the agencies, to ensure the most effective investigations and to avoid duplication of effort. EPA has initiated efforts to establish agreements with State OSHAs. We are investigating means to coordinate with other entities such as State Emergency Response Commissions (SERCs) and State Fire Marshals.

RECOMMENDATION: EPA should create increased public and private awareness of its investigative program.

REPLY: EPA has already presented its accident investigation program at numerous national public conferences and state workshops during the last year. We are developing an outreach program to share results of investigations to all stakeholders and to alert them to particular hazards identified in the course of investigations. This activity will assist in making the program known and can be the occasion for working with particular industries or trade associations about specific hazards defined after an accident. We are preparing such an alert for ammonium nitrate facilities, which will be of use not only to the affected industry but also to communities having such facilities nearby. We can build on our existing work with professional societies like the American Institute of Chemical Engineers' (AIChE) Center for Chemical Process Safety (CCPS) and others, as well as trade associations, with whom we have worked on aspects of the chemical accident provisions of the Clean Air Act Amendments. We have begun developing fact sheets and will continue to explore other vehicles and opportunities for outreach.

RECOMMENDATION: EPA should clearly articulate the national goals and criteria for accident investigation.

REPLY: We agree that this is important to the integrity and acceptance of our investigations. We will include this element explicitly in the outreach activities noted above, as well as in our agreements with federal, state and local entities with whom we will work in particular investigations. As noted above, our protocol for investigations can serve this purpose as well, as it will include discussion of goals and objectives of investigations; an explanation of EPA and OSHA authorities; and procedural steps for the conduct of investigations. The document will be available to the public and to all stakeholders.

RECOMMENDATION: EPA should draw upon the existing experience of NTSB and other agencies for assistance in the evolving program.

REPLY: We are drawing upon the experiences of the National Transportation Safety Board (NTSB), the Bureau of Alcohol, Tobacco and Fire Arms (BATF), OSHA, and the National Institute of Standards and Technology (NIST) in accident investigation in developing draft protocols and training for our investigators. We will continue to work closely with these agencies and others. We also can access expertise from the National Response Team, a coordinating body of 15 federal agencies having responsibilities for various aspects of dealing with hazardous materials. It should be noted that we are working with these agencies and others to assemble ways to obtain expert assistance for very specific expertise which may be needed in the course of a particular accident investigation.

Additional notes and recommendations:

The expert reviewers of EPA's report, in addition to articulating the above recommendations for EPA in their summary, commented on a number of specific issues concerning the Terra Industries investigation and included additional recommendations in the text of their report:

ROLE OF THE SPARGER:

One issue is the particular role of the sparger in the accident at Terra Industries. To date, EPA has not received any additional evidence or scientific data that would lead to altering any findings, conclusions, or recommendations in the final report.

IDENTIFICATION OF ROOT CAUSES: Another issue raised by the reviewers was that EPA should provide more attention to the relationships between root causes and conclusions in the report. That is, the conclusions themselves were less explanatory of root cause than was the body of the discussion of the report. EPA acknowledges that some root causes should have been better explained in the conclusion section of the report. In future accident investigation reports, EPA will provide better identification and summary of root causes of the accident as well as correlating the root causes with the recommendations. In addition, EPA provided in the Terra report general recommendations to the ammonia fertilizer industry as a whole to prevent conditions such as those existing at Terra from recurring.

NATIONAL NETWORK OF INVESTIGATIVE CAPABILITIES:

The reviewers noted that EPA should consider a national network of investigative capabilities and expertise as its accident investigation program matures, and should include in the network integrating the use of personnel or contract services with particular expertise and should also include the expertise of OSHA, states, etc. The joint EPA/OSHA investigation protocol now being prepared notes that EPA has a contract in place to provide technical assistance for accident investigations. This contract also allows EPA to access, as needed, experts in various technical fields to assist in information gathering and analysis. In addition, EPA is developing a list of available EPA regional staff and contactors with their expertise whom EPA could rely upon for assistance in investigations. As noted above in a reply to a related recommendation, EPA can also utilize capabilities of other federal agencies, for example the testing and analysis laboratories of NTSB, NIST, and EPA. EPA and OSHA will also solicit the expertise of other Federal agencies, for example, BATF, NTSB, DOD, and DOE.