SI Figure 1. Methodological workflow and destination of results. SI Table 1. Methodological assumptions, anticipated biases, tests, data adjustments, and implications. SI Table 2. Number of individual land use parcels intersected by address points located within 200m of an active UGS well across the six states observed. Bold highlighted rows indicated land use types that contain addresses that were censored from inclusion as a residential housing unit. SI Figure 2. Frequency histograms of housing units within 200 m (657 ft) of active UGS well(s) by distance from well. Red lines indicate each stateâ s applicable regulatory surface setback distance for conventional oil and gas wells. The number displayed represents the number of visually verified housing units within the setback distance. The number displayed in the top right corner signifies total intersects including duplicates. SI Figure 3. PPA vs. ABODE population estimates of areas within 200m of active UGS wells. Dashed lines represent linear fits. Note each state plot contains unique scales. SI Table 3. UGS well and building counts within surface setbacks with visual verification results. SI Table 4. Legislative oil and gas setback restrictions for buildings. SI Figure 4. Total populations at the census block level vs. census block area for all six states assessed. SI Figure 5. Neighborhood level view of housing unit/address point and well data quality issues. SI Table 5. Address data original sources and publish date. OA = OpenAddresses.io, NAD = National Address Database. (DOCX 85961 kb)