Masterplan Development for Dioxin Remediation at Bien Hoa Airbase

Trigon Associates spearheaded the development of a strategic “Roadmap to Masterplan Development,” for the effectively remediating dioxin at the Bien Hoa Airbase in Vietnam. This was the largest remaining area of dioxin contamination in the world and the largest remediation project undertaken by the U.S. Government. The masterplan was developed by engaging with GVN stakeholders over a series of five Roadmap Workshop meetings spanning ten months from September 2019 to June 2020. Consensus was achieved on critical project issues such as Applicable or Relevant and Appropriate Requirements (ARARs) and treatment options. These meetings fostered open communication, enhancing understanding of project challenges and risks while cultivating relationships among stakeholders. Consequently, the Masterplan gained swift approval from ADAFC and USAID with minimal revisions.

The Masterplan outlined a comprehensive 10-year strategy for remediating dioxin at the Airbase, distinguishing between high-concentration (HC) and low-concentration (LC) materials across two five-year phases (2019 – 2025 & 2026 – 2030). Summary tables provide an overview of activities, dependencies, milestones, excavation quantities, and estimated costs. Detailed schedules reflect progress up to June 2023.

Trigon provided engineering services throughout Masterplan development and implementation, addressing gaps in previous data through extensive sampling and analysis plans. They conducted supplemental site investigations to optimize understanding of contamination for remedial action design. Trigon’s involvement also extended to preparing design packages, technical specifications, and supporting USAID in procurement processes for construction and treatment contracts. We facilitated virtual site tours amid COVID-19 restrictions, ensuring transparency and accessibility to potential bidders.

The major components of the Roadmap Masterplan included:

• Site Sampling and Assessments
• Site Sampling Analysis Plan
• Site-wide Hydrology Study & Modeling
• Design and Construction of a Pre-Treatment Storage Area, High-Concentration Temporary Storage Area, and a Long-Term Storage Area for Contaminated Material
• Design and Construction of Detention Ponds
• Design and Construction of Access Roads
• Detailed Treatment and Remediation Plan