Wastewater treatment in Idaho in the face of emerging contaminants: policy lag, utility burdens, and infrastructure readiness

Abstract Emerging contaminants, including pharmaceuticals, per- and polyfluoroalkyl substances, organic compounds, cyanotoxins/cyanobacteria, and microplastics, represent a growing threat to water quality and public health. A significant policy lag exists at both the federal and state levels, leaving wastewater utilities with undefined regulatory targets and inadequate infrastructure to manage these risks. We use Idaho as a case study to examine the dynamic between evolving scientific understanding of emerging contaminants and static regulatory frameworks. We analyze Idaho’s current wastewater policies, finding no binding standards or monitoring requirements for emerging contaminants despite available federal funding. Our assessment reveals that most treatment facilities lack the technical and financial capacity to remove emerging contaminants, risking continued discharge into water bodies. Our paper highlights the burdens placed on utilities, particularly in small and rural Idaho communities, and identifies critical gaps in regulatory guidance, long-term planning, and equitable resource allocation. We conclude with a four-step recommendations framework: (1) developing flexible regulatory guidance, (2) enhancing targeted financial and technical assistance, (3) establishing a statewide emerging contaminant monitoring program, and (4) investing in risk communication and public engagement. These steps are essential for bridging science and policy, ensuring infrastructure readiness, and safeguarding Idaho’s water resources in the face of emerging contaminant challenges.