A threat graph, not a lead app

The durable objects are a place (PWS or well tract), an analyte, a sample, a story, and an opt-in alert. Lead in drinking water is the first adapter. PFAS, nitrates, boil-water events, air, and soil reuse the same loop.

Seeded samples by threat

Live threats have household or official numbers today. Next and later threats are catalogued so the schema does not have to be rewritten.

Threat	Status	Category	Thresholds	Why it fits
Lead	live	drinking water	action 15 ppb · health 1 ppb	Leaches from service lines, solder, and fixtures. There is no safe blood-lead level. Official 90th-percentile sampling can miss individual homes.
Copper	live	drinking water	action 1.3 ppm	Corrodes from pipes and fixtures. Often travels with lead and is included in certified lead-and-copper kits.
PFAS	next	drinking water	health 4 ppt	Persistent industrial chemicals. Official monitoring is uneven. A later kit SKU and story layer reuse the same PWS + alert model.
Nitrate	next	drinking water	action 10 mg/L	Agricultural and septic contamination, especially in private wells that sit outside Safe Drinking Water Act coverage.
Arsenic	next	drinking water	action 10 ppb	Geologic and industrial. High-stakes for well communities and some small systems.
Disinfection byproducts	next	drinking water	action 80 ppb	Form when chlorine reacts with organic matter. A plant-level problem official data already tracks — useful as an Official-tier alert.
E. coli / boil-water	next	drinking water	—	Acute microbial risk. Maps onto Emergency-tier alerts and existing boil-water notices.
Fine particulate matter	later	air	—	Same subscribe-by-place, story, and alert machinery. Different ingest adapters (AirNow, PurpleAir).
Soil lead	later	soil	—	HUD Healthy Homes and childhood lead programs already fund paint and soil work. A later kit type, same household graph.