---
title: "Environmental history: address-level proximity-ranked TRI/RCRA + county environmental composite (national)"
method: POST
path: "/api/locus-environmental-history-lookup"
tags: ["environment", "hazardous-materials", "toxic", "water", "radon", "composite", "read-only", "paid", "x402", "category:environmental"]
---

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

`POST /api/locus-environmental-history-lookup`

## Request

- Base URL: `https://api.locus.report`
- URL: `https://api.locus.report/api/locus-environmental-history-lookup`
- Auth: one of:
  - API key in header `PAYMENT-SIGNATURE`
  - API key in header `Authorization`

EPA TRI and RCRA facilities, nearest large-quantity generator, and county radon and background composite for an address, for buyer, owner and lender agents. Returns the same records as locus_environmental_history. Use this when your client can only call paid x402 routes. Use locus_environmental_history instead when you can call Locus free tools (REST tools/call or MCP).

## 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`

Atomic read result. A substantive result is paid; an empty/out-of-coverage result carries charged:false (x402 settlement suppressed).

- object

## Other responses

- `400`: Invalid request body.
- `402`: Payment Required. For x402 v2, repeat the identical request with a valid PAYMENT-SIGNATURE header (legacy X-PAYMENT is accepted for compatibility), or use Authorization: Payment for MPP Tempo when advertised in x-payment-info.offers.

---

[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)