# Bare steel tanks in Colorado — why the material matters

> 14,326 of Colorado's 47,538 registered tanks are asphalt-coated or bare steel, across 5,357 facilities. What that means and what it does not.

## Bare steel, and why it is the number to know

**14,326** tanks — 30.1% of the register — are recorded as asphalt-coated or bare steel.

### The one physical fact these files carry

Most of what a tank register records is administrative. The material is
not: it is a physical property of the tank, and it decides how a tank fails.
Unprotected steel in wet ground corrodes; corrosion makes holes. That is the
whole mechanism, and it is why the federal upgrade rules required protection
— cathodic protection, a fibreglass shell, or fibreglass throughout.

| Material recorded | Tanks | Share |
|---|---|---|
| Asphalt Coated or Bare Steel | 14,326 | 30.1% |
| FRP: Fiberglass Reinforced Plastic | 5,776 | 12.2% |
| ST: Cathodically Protected Steel | 5,704 | 12.0% |
| Unknown | 4,846 | 10.2% |
| AST: UL142/Equiv. | 4,399 | 9.3% |
| AST: UL2085/Equiv. (Protected) | 1,434 | 3.0% |
| Not Listed | 1,181 | 2.5% |
| Fiberglass Reinforced Plastic | 669 | 1.4% |

### ⚠️ What this number is not

Not a leak, and not a breach. Many of these tanks are long closed —
the register keeps them. The file records what a tank is *made of*, not
its condition, and a maintained, monitored steel tank is not the same as one
forgotten under a car park.

Read with the year the tank went in, which the record also carries, it is
the closest a public file gets to telling you whether to look harder.

### ⚠️ And one field we do not use

The register has a `tank_wall_type` column — single or
double walled — which would be genuinely useful. It is filled on
**1,013 rows out of 51,987**. We load it and never put it on a
page: a field filled at 2 % that appears in a table reads as information when
it is a hole.

### Where they are

| County | Facilities | Share |
|---|---|---|
| [Denver](/county/denver.md) | 2,630 | 13.3% |
| [El Paso](/county/el-paso.md) | 1,871 | 9.5% |
| [Adams](/county/adams.md) | 1,578 | 8.0% |
| [Jefferson](/county/jefferson.md) | 1,411 | 7.1% |
| [Arapahoe](/county/arapahoe.md) | 1,256 | 6.4% |
| [Weld](/county/weld.md) | 1,156 | 5.8% |
| [Larimer](/county/larimer.md) | 943 | 4.8% |
| [Mesa](/county/mesa.md) | 708 | 3.6% |
| [Boulder](/county/boulder.md) | 707 | 3.6% |
| [Pueblo](/county/pueblo.md) | 630 | 3.2% |
| [Douglas](/county/douglas.md) | 495 | 2.5% |
| [Garfield](/county/garfield.md) | 372 | 1.9% |
| [Eagle](/county/eagle.md) | 316 | 1.6% |
| [La Plata](/county/la-plata.md) | 277 | 1.4% |
| [Grand](/county/grand.md) | 258 | 1.3% |
| [Montrose](/county/montrose.md) | 246 | 1.2% |
| [Fremont](/county/fremont.md) | 228 | 1.2% |
| [Routt](/county/routt.md) | 218 | 1.1% |
| [Morgan](/county/morgan.md) | 214 | 1.1% |
| [Montezuma](/county/montezuma.md) | 206 | 1.0% |
| [Pitkin](/county/pitkin.md) | 198 | 1.0% |
| [Chaffee](/county/chaffee.md) | 187 | 0.9% |
| [Delta](/county/delta.md) | 185 | 0.9% |
| [Logan](/county/logan.md) | 184 | 0.9% |
| [Summit](/county/summit.md) | 178 | 0.9% |
| [Rio Grande](/county/rio-grande.md) | 168 | 0.9% |
| [Broomfield](/county/broomfield.md) | 157 | 0.8% |
| [Gunnison](/county/gunnison.md) | 155 | 0.8% |
| [Otero](/county/otero.md) | 152 | 0.8% |
| [Las Animas](/county/las-animas.md) | 131 | 0.7% |

County pages break out how many of their facilities carry bare steel. The count for one facility is on its own record, one search away.

### An old steel tank on a property you own or are buying?

The register says what a tank is made of and when it went in. It does not say what condition it is in — that takes someone on site.

We take no commission and we recommend no firm. We have no arrangement with any contractor today — we are collecting these requests in order to go and find them. [What we do with this](/privacy.md).

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