Introduction: Managing per- and polyfluoroalkyl substances (PFAS) risk presents challenges from many angles both technical and regulatory. The world has largely been taken off guard by the scale and pace of the problem, misconceptions, media frenzy, adversarial relations, and a shortage of reliable information and tools contribute substantially to this emerging challenge. In this difficult environment, stakeholder and community engagement is crucial. Stakeholder and community engagement must be proactive, robust, well documented, well staffed, nimble, and adroit. Australia’s Department of Defence PFAS Investigation and Management Program has a model stakeholder and community engagement program in place, which aims to keep the community informed and involved. Objective: The Lavarack Barracks Environmental Investigation is one of 13 investigations currently being conducted across Australia by the Department of Defence. Lavarack Barracks, located in Townsville in North Queensland, has delivered a stakeholder and community engagement process consistent with the Department of Defence’s approach to engagement across Australia, while also addressing differences in the local community. Consistent information is delivered, the community is involved, and media interest is proactively managed. PFAS, by their very nature, present acute and persistent challenges that require deliberate action. What is unknown about PFAS from a human health perspective is as challenging to manage as the widespread contamination that has penetrated many communities. Engagement, through carefully constructed and truthful, frequent, and accessible messaging, is key to establishing trust and credibility with stakeholders ranging from community members to local and state regulators, health officials, and watchdog organisations. Methodology: The Lavarack Barracks stakeholder and community engagement process uses multiple complimentary systems to inform and involve interested community members. Both procedure and tools are presented and shared. A database sits behind the engagement process, and all interactions with stakeholders and community members are captured. There is a page on the Defence website that provides contact information for the project team, including a telephone hotline, and an email address. Same-day responses are offered to enquiries. Fact sheets and project updates prepared for the project are stored and kept current on the webpage, along with project deliverables. At the outset of the project, a survey was used to gather information about the use of bore and surface water in the investigation area. Community walk-in sessions have been held regularly, and are attended by the project team, and representatives from Defence and regulatory agencies. The answers to project Frequently Asked Questions are comprehensive and messaging is consistent across the project, and between other Defence investigations. The walk-in sessions are scheduled in accessible locations and are promoted using print and online advertisements. We have delivered these sessions at a conference venue, at the local stadium, and in a local shopping centre, helping us to reach diverse community members. A spokesperson is nominated for communication with the media. Conclusions: The net result of this carefully planned program, executed in the residential suburbs adjacent to Lavarack Barracks, is consistency, transparency, confidence, and trust to the maximum extent possible in an environment of uncertainty and unknowns. This presentation will draw on the experience at Lavarack Barracks to highlight the most effective tools for stakeholder and community engagement, as well as key lessons learned through the delivery of the engagement process. Leisa Prowse, Director, Leisa Prowse Consulting Leisa Prowse has more than 25 years experience in community and stakeholder engagement, communication, social impact assessment, and local and regional planning. With a rare blend of communication and town planning qualifications, and more than 200 projects under her belt, Leisa understands complex and contentious planning and infrastructure projects. Leisa has a proven track record in developing and implementing comprehensive engagement and communication strategies, delivering the full range of techniques and successfully managing sensitive stakeholder and community issues. Leisa is skilled at facilitating discussions with individuals and groups ranging in size from five people to 5,000, and she has worked with communities in urban, regional and remote areas, and stakeholders representing a range of cultural groups. Leisa is a member of the International Association for Public Participation (IAP2) and IAP2 Australasia Ambassador.