CheckYourZone

In December 1984, a Union Carbide plant in Bhopal leaked methyl isocyanate into a sleeping city. Three thousand people dead before morning. Two years later, Congress passed EPCRA — the Emergency Planning and Community Right-to-Know Act. The right to know is literally in the name.

Forty years on, 12,963 facilities file worst-case scenarios with the EPA every year. 140 regulated chemicals. Every plume radius, every accident, every quantity stored on-site. All public record, by law.

Also: completely illegible to the people who need it most.

The problem

The EPA maintains something called the Risk Management Program database — RMP data. Facilities that store threshold quantities of dangerous chemicals have to report what they have, how much, and what happens if the worst case hits. It’s one of the most important public safety datasets in the country, and the infrastructure that surfaces it has been quietly eroding. The Distance2Endpoint column — the one that tells you how far a chemical plume travels — is all nulls. Empty fields where life-or-death math should be.

So we do the math ourselves.

What it does

Give CheckYourZone a ZIP code or county and it returns every RMP facility whose worst-case dispersion radius could reach you. We calculate those radii using Gaussian plume modeling and we show our work. No black boxes, no trust-us disclaimers. The inputs are published, the methodology is documented, the code is open.

Three pillars: awareness (here’s what’s near you), agency (here’s what to do), transparency (here’s the math).

For each chemical, there’s a full reference page — dispersion distances, PPE requirements, emergency response guidance, exposure limits, incident history. Over 120 chemicals have been through a rigorous review pipeline. Not a quick copy-paste from a safety data sheet — a structured multi-pass review that cross-references NIOSH, ATSDR, the ERG, and the CSB investigation archive.

Who it’s for

Renters who can’t afford to move and deserve to know what’s stored two miles upwind. Fire chiefs doing pre-incident planning who need dispersion data that doesn’t require a CAMEO license. LEPC coordinators. Parents. Anyone who’s ever heard the emergency siren and didn’t know why.

This isn’t facility-shaming. The data is already public. We’re just making it readable at the exact moment the government is stepping back from doing that job.

The stack

Nuxt 4 and TypeScript on the frontend. CozoDB for structured data — facility records, accident history, chemical dispersion tables, and a local geocoding layer built from HUD ZIP centroids and Census county data. Zero external API dependencies for the core zone lookup. MapLibre GL for mapping. Tailwind v4 for the UI.

Everything runs without phoning home. That’s not an accident — it’s the point. A civic safety tool that depends on a third-party geocoding API is one corporate decision away from going dark.

The revenue question

Free public access, always. The sustainability model is B2B: facility verification services, municipal API access, tiered data for professional use. Not grant-dependent, not ad-supported. The people who need this most aren’t the ones who should be paying for it.