1987 Tindal Environmental Contingency Plan
The Department of Defence commissioned an Environmental Management Plan for the operation of RAAF Base Tindal in 1987. This plan consisted of ten task-specific management plans, including the Environmental Contingency Plan, prepared by Kinhill Engineers Pty Ltd.
The Environmental Contingency Plan contemplated the risk and mitigation for 19 different contingency events, including release of fire-fighting foam to the environment. Appendix F to the plan included procedural requirements for foam systems published by the Department of Housing and Construction and information about the foam published by 3M.
The plan was concerned primarily with the collection and proper treatment of foam residues, recognising that the release of large amounts of foam to the environment would cause adverse effects because foam can suffocate living organisms. Based on the scientific understanding of the time, the plan stated that “AFFF and its components are not considered to be dangerous substances, nor are they harmful to the aquatic environment after proper treatment” and “Because of the small proportion of fluorocarbons in AFFF and of the high degree of dilution during treatment and in receiving waters, fluorocarbons are not significant environmental contaminants”.
The plan did not provide any advice regarding the potential for long range environmental transport of PFAS, nor its persistence in the environment or propensity to bioaccumulate. The science on those aspects was not developed at that time.
Defence now understands that the recommended methods of treating fire-fighting foam in sewage treatment plants did not remove PFOS and other persistent chemical residues in the foam.