Determining the connectivity of tribal communities to wastewater treatment facilities for use in environmental contamination and exposure assessments by wastewater-based surveillance

Limited information is available on the connectivity of Tribal communities to wastewater treatment facilities (WWTFs). This is important for understanding current sanitation infrastructure which drives public health and community construction, knowledge of potential routes of exposure through lack of infrastructure and/or discharging facilities, and opportunities to assess community health through wastewater-based surveillance (WBS). The objective of this work was to assess current wastewater infrastructure for 574 Federally Recognized Indian Tribes (FRITs) in the United States (US) to determine the number and location of facilities on or adjacent to Tribal reservations and Off-Reservation Trust Lands, with the goal of determining the feasibility of employing wastewater-based surveillance within these communities and to identify areas with inadequate sanitation infrastructure. Here, we identified available National Pollutant Discharge Elimination System (NPDES) wastewater discharge permits in the Environmental Protection Agency’s Environmental Compliance History Online database to assess proximity to and within spatial boundaries of Tribal lands. These data were coupled to race data and tribal spatial boundary information from the US Census Bureau. 94 FRITs have registered NPDES permits within Tribal boundaries including a total of 522 facilities. 210 of these are American Indian (AI)-serving (>50% AI) with the ability to reach 135,000 AI-people through the wastewater network to provide community health assessments via WBS. Of the remaining facilities, 153 predominantly serve non-Tribal populations raising concerns about infrastructure placement and indigenous sovereignty. 523 FRITs were identified as without permitted discharging WWTFs, which may suggest inadequate or alternative infrastructure.