Filter by parcel identifier (PIN) to check a specific property's onsite sewage designation
Request f=geojson for GeoJSON output for mapping use cases
Cross-reference results with King County's Esri Hub open-data landing page (gis-kingcounty.opendata.arcgis.com) for a human-readable field glossary before parsing raw responses
Known gotchas
The service is a MapServer, not a FeatureServer — some client libraries default to FeatureServer query semantics and need the MapServer path adjusted
This layer flags parcels with onsite sewage designations; it isn't a permit-transaction history — permit-level detail lives in King County's separate permitting system, not this GIS layer
No authentication required, but confirm the current layer ID via the service's own metadata response, since county GIS teams periodically renumber layers during updates
Give your agent this knowledge — and 15,500+ more routes
One MCP install gives any agent live access to the full route map across 5,700+ domains, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp
Need this verified for your stack — or a route we don't have yet?