How we count: method for new plants, factories and tours

New plants

Included: US manufacturing plants announced in 2021 or later with at least $25 million or 100 jobs announced. Expansions count when announced as a distinct project.
Every project needs a primary source: a company release, a state economic-development or governor release, an SEC filing or a federal award notice. News can add detail but can't put a project on the list.
Status is computed from dated milestones: announced, groundbreaking or construction started, production started or opened, paused, cancelled, closed. The newest milestone sets the status. When that milestone comes only from news, the status carries a "reported" label.
Investment and jobs are what the company or state announced. We don't estimate missing figures or count blanks as zero.
We recheck projects weekly and show a last-checked date on every page.

Existing factories

Active facilities with a manufacturing NAICS code (31–33) in EPA's Enforcement and Compliance History Online (ECHO), pulled November 1, 2026. ECHO covers facilities EPA regulates, so it is a large subset of all factories, not all of them.
A facility gets its own page when it reports to the Toxics Release Inventory and its record includes location and industry codes. Before publishing, we compare a random sample of 100 pages against EPA's facility reports field by field.
Records are shown as published, with dates and a link to EPA's detailed facility report. They are not ratings.

What the records on a factory page mean

Toxics Release Inventory (TRI): facilities in covered industries file a yearly report when they make, process or use listed chemicals above set amounts. Filing is a reporting duty, not a finding.
Clean Air Act: EPA's air program classes a source as major, synthetic minor (permit limits keep it below major levels) or minor. The class sets which permits apply.
Clean Water Act: facilities that discharge to water hold NPDES permits, classed major or non-major.
Hazardous waste (RCRA): generators are classed by how much hazardous waste they produce a month: large (1,000 kg or more), small (100 to 1,000 kg) or very small (under 100 kg).
Inspections: the count of inspections and evaluations ECHO records in the last five years, with the latest date.
Industry codes are as reported in EPA's Facility Registry and can lag changes in what a plant makes.

Counts by state and industry

Establishments and employees come from the Census Bureau's County Business Patterns 2023 (mid-March employment). Census marks some employment figures as having moderate or high noise; we flag the high ones.

Tours

Each tour is checked on the operator's own website. We record only what the operator states and leave the rest blank. We say whether you see a real production floor, a visitor center or a ride.