Know your data sources.

Utah DEQ — Voluntary Cleanup Program, Brownfields, CERCLIS hazardous-waste sites. - searchVoluntaryCleanup ⭐ ~142 VCP sites (mostly Salt Lake County) - searchBrownfields ~29 sites (Targeted 18 + Other 11 combined) - searchHazardousWasteSites ~145 active CERCLIS sites (~469 incl. archived) - getServiceInfo upstream quirks: AGOL services1.arcgis.com/99lidPhWCzftIe9K owned by UtahAGRC. All 4 layers use SITECNTY (NOT COUNTY) UPPERCASE. Date columns are MM/DD/YYYY strings (NOT epoch). VCP STATE = 'UT' only and POSTTONET = 'Yes' only — degenerate. SITEREM has ARCHIVED Err/No/Yes; default activeOnly filters to "No" (~145 vs raw 469). No UT-published RCRA hazardous-waste-handler service exists — for RCRA G/T/TSDF use EPA Envirofacts (already exposed).