---
title: "Environmental history: address-level proximity-ranked TRI/RCRA + county environmental composite (national)"
method: POST
path: "/api/locus_environmental_history"
tags: ["environment", "hazardous-materials", "toxic", "water", "radon", "composite", "read-only", "free", "free"]
---

# Environmental history: address-level proximity-ranked TRI/RCRA + county environmental composite (national)

`POST /api/locus_environmental_history`

## Request

- Base URL: `https://api.locus.report`
- URL: `https://api.locus.report/api/locus_environmental_history`
- Auth: none required

EPA TRI, RCRA, SDWIS, EPA radon zone, and NRC/PHMSA verify links for an address or county, for buyer, owner and lender agents. radonHeadline plus addressProximity lead; county background may match all county properties. National by lat/lng or state and county; not incident confirmation or a safety verdict.
Use this when you can call Locus free tools (REST tools/call or MCP).
Use locus-environmental-history-lookup instead when your client can only call paid x402 routes; it returns the same records. Direct flat-body route for this one free resource; no API key, payment, or catalog wrapper. Return only the cited bounded evidence described here; this route never produces a paid brief or full report.

## Request body

- object
  - `address` string: Optional US street address; used to derive county when state+county or lat/lng are not provided.
  - `latitude` number: Optional decimal latitude; provide with longitude to derive county from the point.
  - `longitude` number: Optional decimal longitude; provide with latitude to derive county from the point.
  - `state` string: Optional two-letter state code; provide with county to skip point resolution.
  - `county` string: Optional county name, e.g. Wake; provide with state to skip point resolution.
  - `radiusMeters` integer: Optional proximity radius in meters for the TRI/RCRA address ranking; default ~5000 (3.1 mi), clamped to ~24000 (15 mi).

## Response `200`

Free cited evidence response.

- object

## Other responses

- `400`: Invalid request body.
- `429`: Rate limited.

---

[API](https://skmtc.dev/locus/apis/locus-api.md) · [All operations](https://skmtc.dev/locus/apis/locus-api/llms.txt) · [OpenAPI document](https://skmtc.dev/locus/apis/locus-api/revisions/ba7786b74adb?raw)