PMP Practice: Evaluate/recommend/reconcile the appropriate conflict resolution solution

Aroha Tāne-Williams is managing a municipal water infrastructure upgrade project for the city of Riverside. During a design review meeting, the lead civil engineer, Mei-Ling Zhao, and the environmental compliance specialist, Amara Okonkwo-Diallo, engage in a heated disagreement about pump station placement. Dante insists the pumps must be located at the northwest corner for optimal hydraulic efficiency and to minimize long-term operational costs. Lila argues this location would require clearing a wetland buffer zone, violating state environmental regulations and potentially delaying permits by six months. Both are refusing to compromise, and the meeting ends without resolution. The project is currently on schedule, and this decision must be finalized within two weeks to avoid delaying the procurement phase. Aroha has verified that both technical positions are valid within their respective domains. Which conflict resolution approach would be MOST effective?