Ollervides formerly served as the Central Director for The School for Field Studies in Baja California Sur, Mexico (2003-2006). As Director, he led a staff team in research, academic curriculum, and community building. Afterward, he joined Waterkeeper Alliance as their Senior Field Coordinator. In this role, he supported non-profit member organizations, assisted with strategic planning, implementation, and enforcement of standards, and helped with outreach initiatives for the Alliance. He served in the role for four and a half years before departing in late 2010.

In 2011, Ollervides joined the River Network as a consultant for the Great Lakes, where he expanded the constituency and served within the Great Lakes watersheds. He was promoted to Leadership Development Manager in 2013. In this role, he helped partner organizations in organizational development. He served in the managerial role until 2019, when he left to become the Executive Director of the Green Leadership Trust. As the first Executive Director, he helped diversity the environmental movement by engaging with the network of organizations and people involved with the Trust. When leadership changed, he served as an Advisor (2021) to help the transition and as a Steering Committee member. He briefly joined the Ocean Conservancy as their Director of Ocean Climate Justice in late 2021 to 2022, helping advance the organization's justice aspects of ocean conservation and the plastic-climate nexus. He was briefly self-employed in 2022 before joining the Green Leadership Trust as their Director of Member Engagement. He returned to the organization after two years, helping recruit, connect, and develop leadership skills among members to advance environmental organizations' missions and the environmental movement's diversity. In addition to his current role, Ollervides is a Resident Lecturer and Adviser on Economic and Ethical Issues in Sustainable Development, Coastal Ecology, and Resource Ecology and Management at Boston University.