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SAWGraph Explorer

A React app for querying the SAWGraph knowledge graph, which holds PFAS contamination data for the United States. You build a question out of two entity blocks and a spatial relationship between them, the app turns that into a sequence of SPARQL queries against five endpoints, and the results land on a map.

This wiki documents the queries. What each one asks for, why it is shaped the way it is, and what to check when it returns something surprising.

Filter dropdowns

Where the options in each filter control come from.

• Dropdowns, the index, including the ones that are fixed lists
• Substance
• Material
• Industry
• Industry counts
• County

Elsewhere in the repository

The wiki is not the only documentation. These live in the repo because they change with the code and are read while working in it:

• docs/ARCHITECTURE.md, how the app is put together, starting from what a knowledge graph is
• docs/SCHEMA.md, the predicate and class inventory per endpoint, plus data coverage by state
• docs/DEBUGGING.md, a log of bugs and graph quirks with their causes
• docs/CONVENTIONS.md, coding standards
• docs/queries/, five complete example questions walked through end to end

Editing this wiki

Do not edit pages in the wiki UI. They are overwritten on every push to main. The source lives at docs/wiki/, so changes go through a pull request alongside the code they describe.