Presentation short abstract

This article examines how drinking-water quality standards in Costa Rica are produced, contested, and lived in the face of pesticide contamination, tracing how regulatory shifts are situated within broader dynamics of global pesticide supply and how they shape uneven chemical geographies.

Presentation long abstract

In July 2024, a truck carrying mancozeb, a widely used fungicide on tropical banana plantations, overturned, spilling its contents into water bodies in Costa Rica’s Barranca River watershed. This event triggered an unsettling debate in a country already grappling with contentious politics over pesticides, given widespread concern over the country’s intensive pesticide use. In this contribution, I explore how pesticide regulatory standards for water quality are produced and contested in relation to the global pesticide complex, shaping uneven chemical geographies. Through ethnographic fieldwork, including semi-structured interviews with state institutions, pesticide firms, community water boards, environmental organizations, academia, and other relevant actors, I unpack pesticide residues as contested, multiscalar objects. The mancozeb emergency raised several questions for state authorities over which actors were responsible for the accident and thus its remediation, and what the state could do to address community concerns over contaminated water. In the wake of this and other scandals over pesticide-contaminated water, the Ministry of Health piloted a major regulatory change to the country’s Maximum Admissible Values, which hitherto followed the same precautionary approach as the European Union (0.1 ug/L). Arguing in part that European standards were unrealistic for a country like Costa Rica, the Ministry introduced a new modality: Maximum Allowable Values Adjusted for Risk. I analyze the discourses surrounding this change and the modalities of contestation.