This mission report describes the finding of an environmental expert in Haiti, who was deployed to assess water contamination in 2016 following Hurricane Mathew. Hurricane Matthew struck south-western Haiti in October 2016, leaving a trail of widespread damage throughout the nation. This hurricane was reportedly the strongest to hit the nation since 1964. The Swedish associate environmental expert was deployed as part of the United Nations Disaster Assessment and Coordination (UNDAC) team, mobilized at the request of the UN Environment/OCHA Joint Unit through the European Union Civil Protection Mechanism. The expert worked in close collaboration with the UN Environment office in Port Salut, focusing on issues related to water and waste. Together with UN Environment, the expert conducted emergency environmental assessments with a focus on water contamination. All activities were undertaken in close coordination with the UNDAC team and the WASH (Water Sanitation Hygiene) cluster.