Know your data sources.

Illinois EPA site remediation, leaking USTs, landfills, brownfields, and federal-facility cleanup via geoservices.epa.illinois.gov. - searchSiteRemediation ⭐ ~6.6K SRP cleanup sites with County + SiteType (64 distinct) - searchLeakingUST ⭐ ~31.3K LUST sites — NO county column upstream - searchLandfills ⭐ ~1041 landfills across 6 status-typed layers - searchBrownfields, searchFederalFacilities, getServiceInfo §0: Environmental/LeakingUST and Environmental/IEPA_BOL_SiteRemediationProgram are DEAD (layers=[], 500s). Live equivalents: Land/LeakingUST, Land/SrpSites. FederalFacilities canonical is layer 1 (parent 0 is group). Active 0/1 ↔ SiteActive Yes/No same partition. All four services in EPSG:4326.

Indiana IDEM Superfund, cleanup, voluntary remediation, hazardous waste, LUST, brownfields, solid-waste via gisdata.in.gov state Hub. - searchSuperfundSites ⭐ ~85 federal NPL & SF list (program=SF) - searchCleanupSites ⭐ ~1.5K State Cleanup Sites (program=SC) - searchVoluntaryRemediation ⭐ ~653 VRP sites (program=VR) - searchBrownfields (~2.3K w/ county), searchHazardousWasteSites, searchLustSites, searchSolidWasteFacilities §0: maps.indiana.edu (build-plan brief) is unreachable (TCP timeout). Canonical data on gisdata.in.gov Hosted/IDEM_Land_Sites — IDEM/ folder requires auth. Layers 1500/1600/1800/1900/2300 share schema and have NO county column (municipality only); 1100 + 1000 have county. agency_interest_id is Double.

New Mexico Environment Department permits and remediation via public ArcGIS FeatureServers. Groundwater discharge covers Permian produced-water and UIC permits. Air-quality facilities span seven classes: major, minor, synthetic-minor, no-permit, exempt, intent, and inactive. Hazardous-waste facilities cover 21 RCRA-permitted sites; voluntary remediation covers VRP cleanups. Groundwater and VRP status values are provider-authored and inconsistent, so status matching is case-insensitive. Non-major air layers can contain millions of emission units; supply county, bbox, or another narrowing filter.

Oklahoma DEQ wellhead protection + remediation + monitoring. Native ArcGIS REST MapServers, no auth. - searchWellheadProtectionAreas ⭐ — drilling-restriction polygons (~5.9K) around PWS - searchRemediationSites ⭐ — Institutional Controls (898) under formal cleanup programs - searchVoluntaryCleanupSites, searchAccreditedLabs (~151), searchAirQualitySites (26) - getServiceInfo quirks: WHPA has NO name / county / facility id — only ZONE (A/B/C) + SOURCE_IND. Filter zone or bbox. Remediation County values dirty (Garfeld vs Garfield, "Tulsa" vs "Tulsa County") — handler LIKE-matches + Title-Case strips trailing " County". LabAccred Lab_Type has typos. Base_Certification_Status always 'Accredited'. Air POLLUTANTS comma-joined; LIKE-matched.