An Old Underground Fuel Tank on Your Property

There is a filler pipe against the wall of the garage, or a rusted vent stack in the flower bed, or the inspector has just written the words possible buried tank. On a house built before the sixties in Tulsa this is not unusual, and the reaction it provokes is almost always out of proportion to what is actually found.

This article covers who regulates these in Oklahoma, how to establish whether there is a tank at all, the difference between a tank and a release, what closure involves, and what any of it does to a sale.

Who regulates it

The Oklahoma Corporation Commission, through its Petroleum Storage Tank Division, enforces the state and federal rules for aboveground and underground tanks holding antifreeze, motor oil, motor fuel, gasoline, kerosene, diesel and aviation fuel.

Under title 17, section 322 of the Oklahoma Statutes, that division is the sole division of the Commission with jurisdiction over releases and spills from petroleum storage tanks. Closure of regulated tanks sits under the Commission's rules at OAC 165:26.

The Division also administers the Indemnity Fund, created by the Legislature in 1989 to help tank owners meet the financial responsibility requirements attached to storage tanks and leaking tanks. Eligibility has conditions, and whether it reaches your situation is a question for the Division rather than for us.

One phone call to the right regulator, before any equipment arrives, is the single most valuable thing on this page.

Ring them before you act. Work done in the wrong order, by the wrong contractor, or without the required notice can close off routes that would otherwise have been open to you.

Establishing whether there is one

Start with evidence rather than with a digger.

• Look for the visible signs. A filler cap or pipe in a driveway or against a wall, a vent stack, a disused copper line running through the basement or crawl space toward a wall, capped pipework near where a furnace used to sit
• Ask the previous owners or long-standing neighbours. On a house of that age somebody usually remembers the conversion from oil to gas
• Check the records. The Commission holds tank records, and while historic residential tanks are frequently not recorded anywhere, it is a free enquiry and it occasionally answers the question outright
• Have a proper scan done if the signs are ambiguous. Ground penetrating radar or a metal survey costs a fraction of what guessing costs and it produces a document rather than an opinion

What you should not do is dig speculatively to have a look. If there is a tank and it has leaked, the moment of discovery matters, and discovering it with a mini digger on a Saturday is the worst possible version.

A tank is not the same as a release

This is the distinction that decides how large the problem is, and buyers and sellers both tend to collapse it into one worry.

A tank is a container in the ground. On its own it is an item to be properly closed or removed, documented, and moved past.

A release means product has escaped into the soil or groundwater. That is a different order of problem, it carries reporting obligations, and site cleanup after a confirmed release brings the Department of Environmental Quality in alongside the Commission.

The great majority of residential situations are the first, not the second. Soil sampling during a proper closure is what tells you which one you have, which is another reason to have the work done by somebody who knows what they are collecting rather than by a general excavator.

What closure involves

Broadly there are two routes, and the right one depends on access, what is above the tank, and what the regulator requires in your circumstances.

Removal. The tank is excavated and taken away, soil samples are collected and the excavation is backfilled. This produces the cleanest documentation and is what most buyers and lenders want to see.

Closure in place. The tank is emptied, cleaned and filled with inert material where removal is impractical, for example under a structure. Whether this is available and what it requires is for the regulator to say.

Either way, the outcome you are actually buying is the paperwork: the closure report, the sampling results and the documentation that the work was done to the required standard. A tank removed with no records behind it is close to useless in a sale, because the next buyer cannot tell a clean removal from an unrecorded one.

We are not publishing a cost figure, because what we could find came from contractors advertising the work rather than from a source we would rely on. Get three written quotes from firms that have been on site, and ask each of them what the Commission requires, who is licensed to do it, and what the report will contain.

What it does to a sale

Lenders and insurers ask. An unresolved possible tank is an open question, and open questions get priced as worst cases by everybody who touches the file.

Buyers overestimate it. Told there is a buried tank, a buyer imagines contamination and six figures. Told there is a tank that was properly closed in 2019, with the report attached, most buyers move on to the kitchen.

Disclosure applies. A tank you know about, a tank you suspect, and any work done belong on the disclosure form. Our article on Oklahoma seller disclosure requirements covers the position. This is not a thing to leave for a buyer's inspector to find, because when they find it they price the uncertainty and the mistrust together.

If the house is on acreage or has other legacy features, our article on an old oil or gas well on your property covers a related question with a similar answer: documentation is most of the price difference.

Where we come in

Find out what you have before you decide anything. A scan and a conversation with the Commission cost very little and they frequently establish that there is no tank at all, or that there is one and it is a straightforward closure. Do not accept a discount on a house because of a pipe nobody has investigated.

If it is a clean closure and you can fund it, do it and sell normally. A documented closure puts the house back in front of financed buyers with the question answered, and that nets you more than we will pay.

Where a cash sale genuinely fits: a confirmed release with cleanup ahead of it, a tank under a structure where removal is disruptive and expensive, or a buyer who has already withdrawn and a timetable you cannot extend. Our page on selling a house that needs repairs sets out how the number is built.

The short version

• The Oklahoma Corporation Commission's Petroleum Storage Tank Division regulates these, and under 17 O.S. 322 it is the sole division with jurisdiction over releases and spills from petroleum storage tanks
• Closure of regulated tanks sits under OAC 165:26. Confirm requirements with the Division before anybody digs
• The Division administers an Indemnity Fund created in 1989. Whether it reaches your situation is a question for them
• Establish whether a tank exists using signs, records and a scan. Do not dig speculatively
• A tank is not a release. Most residential situations are a container to be closed, not a contamination event
• Removal or closure in place, and either way what you are buying is the paperwork
• Disclose a tank you know about or suspect
• Documentation is most of the price difference. Unknowns get priced as worst cases