# About tanks-co — scope, sources and limits

> How this site is built: which files are joined, what is deliberately not published, and what the records cannot say.

## How this site is built

An independent search layer over three public files. Not affiliated with the Colorado Division of Oil and Public Safety.

### Three files, joined at 100 %

The Division publishes the facilities, the tanks and the petroleum releases
as separate datasets, all keyed on `facility_id`. This site loads
all three and joins them.

Both join rates were measured before anything was built and both are
**100 %**: every facility ID in the tank file and in the release
file is present in the facility list. That is the cleanest chaining in this
portfolio — on another state, one of the candidate keys matched 0 % and
would have attached releases to nothing.

### ⚠️ What no page here says

**That a site is polluted.** None of the three files carries a
concentration, a volume, a depth or an extent. Every figure here is a count, a
stage or a date. [What a stage actually is](/stage.md).

**A list of facilities with unfinished cases.**
506 addresses. Under such a heading they would read as a verdict on
each. The counts and their distribution are published; the individual record
is one search away.

**Personal contact details.** The release file carries a
contact name, phone and email. They are *not requested at download*,
not stored, and the loader stops if it finds them.

### ⚠️ Two fields handled carefully

`tank_wall_type` is filled on 1,013 rows of 51,987 — 2 %.
It is loaded and never shown: a field that sparse on a page reads as
information when it is a hole.

4,449 tank rows repeat the same facility and tank tag. They are collapsed
to one physical tank each, which is why this site counts
47,538 tanks where the raw file has 51,987 rows.

### Why `tanks-co` and not `ust-co`

Because Colorado publishes aboveground tanks alongside buried ones —
UL142 and UL2085 vessels sit in the same file. Calling the site
« underground » would be wrong in the domain name
itself.

### How the pages are chosen

A county gets a page at 40 facilities (56 of
65 qualify, covering 98.9%); a category at
40; a county-and-category page at 80. Cities
get no page at all — a city is a subset of its county, and two pages
about the same facilities is duplication by construction.

### Sources

Three datasets from the Colorado Division of Oil and Public Safety on data.colorado.gov, all public domain.
Our copy is from **2026-08-21**. For anything a transaction
depends on, use the
Division’s own records .

The Division publishes these three files as public-domain open data. They record that a tank exists and that a release was reported, with the stage the case has reached — and carry no measurement of soil, water or extent. Nothing here is an environmental assessment.

---

Página: https://tanks-co.pages.dev/about/
Fonte: Regulated storage tanks, facilities and petroleum releases — Colorado Division of Oil and Public Safety (three datasets)
Recolha: 2026-08-21