Ever wonder what happens when you find out the property you are interested in buying or the one you own, has an oil tank on it?

Please read on to see what Larry Stamp of Cameo Home Inspection Service of Olympia, WA has to say:

All About Oil Tanks In Thurston County

Thurston County has an estimated 4,000 heating oil tanks used for space heating of homes, churches, schools, and small businesses. Tanks are either above or below the ground. A typical tank is made of steel, unfortunately steel is susceptible to rust (or corrosion). Over time, corrosion (particularly underground tanks in tight, damp soils) may cause leaks, leading to possible contamination of soil, groundwater, and surface water.

A property owner can be held liable for contamination or environmental damage caused by a leaking tank. It is, therefore, in the property owner’s best interest to determine if a tank is leaking. Oil tanks that have been out of use for more than one year must be removed from the ground or properly abandoned (decommissioned in place).

There are two main areas of legal or regulatory concern regarding residential heating oil tanks, one dealing with environmental contamination and the other with fire and safety issues. The Model Toxics Control Act (MTCA; RCW 70.105D) and its implementing regulations (WAC 173-340) contain the state’s requirements governing investigation and clean up of contaminated sites. MTCA applies to contamination caused by heating oil tanks that have leaked into the surrounding soil. The 1997 Uniform Fire Code, adapted by WAC 51-44, requires that heating oil tanks out of service for a period of one year shall be decommissioned by using one of the following processes:

1. Removal from the ground and restoration of the site in an approved manner.

2. Abandonment in place by filling the tank completely with an approved, inert solid material.

3. Tanks of 1,100 gallons or less may be left empty provided they are first pumped and cleaned, and have the fill line capped or plugged, below grade, to prevent refilling of the tank. (NOTE: Some local jurisdictions do not permit this “clean and cap” method. Check local requirements before beginning any decommissioning process.)

A potential third regulatory requirement is adherence to local building codes. Check with your local jurisdiction (incorporated city or the county) to confirm requirements, depending on the method to be used for decommissioning the tank. Obtaining the proper permits is the responsibility of the owner, not the contractor. However, many contractors include this process in their service. If the contractor obtains the permits, the owner must make sure to receive copies. Soil tests are always strongly recommended because they are an objective way to legally document whether the site is contaminated or not.

Pollution Liability Insurance Agency

Why It Was Created

The Legislature found that many owners and operators of underground storage tanks (USTs) could not purchase pollution liability insurance either because private insurance was unavailable, at any cost, or because owners and operators could not meet the rigid underwriting standards of existing insurers. The Commercial Underground Storage Tank Reinsurance program was created by the Washington State Legislature in 1989 and commenced operation in September of that year.

PLIA was established to provide pollution liability insurance that is available and affordable, thereby allowing owners and operators to comply with the financial responsibility regulations of the federal Environmental Protection Agency (EPA) and the Washington State Department of Ecology.

How Reinsurance Works

PLIA enters into contracts with private insurers to market pollution liability insurance to the owners and operators of the USTs located in Washington State. PLIA acts as the reinsurer for those private insurance companies. Reinsurance, in the case of the pollution liability insurance program, means that PLIA shares a portion of the cost of settling claims with the contracted insurance companies. Those insurers are required to provide pollution liability insurance coverage to owners and operators of petroleum USTs located in Washington State. As the reinsurer, PLIA assumes part of the risk for each loss and insulates the primary insurer in the case of an exceptionally large loss. In the case of a $1,000,000 policy, PLIA is responsible for settlements over $75,000. The insurer is responsible for settlement of most claims while protected by the state from severe losses

Who Is Eligible For Coverage

Insurance Policies are available to any owner or operator whose tanks meet the minimum EPA technical requirements, are properly registered with Ecology and meet minimum leak detection standards. Coverage can be provided for UST sites where petroleum contamination or a pre-existing leak is known to exist. Such sites may be insured under the program only if the owner or operator has a plan for proceeding with corrective action. Where pre-existing contamination has been identified, the owner or operator at the time of filing a claim would have the burden of proof that the claim is not related to that pre-existing release.

1.800.822.3905 or 1.360.407.0520

Public Records Request:

Removing or Decommissioning a Residential Heating Oil Tank

1. Determine if the owner will do the work or hire a contractor.

Hiring an experienced, unbiased contractor to do the work is recommended. The owner can accomplish

many of the following tasks; however, persons inexperienced with these procedures may harm themselves or the environment. These tanks have exploded under certain conditions. Therefore, unless the owner has suitable knowledge, training and experience, he or she should hire a qualified contractor to do this work

2. Determine what is in the tank.

By inserting a long stick to the bottom of the tank, the depth of the oil inside can be determined. It is possible that water will also be inside, which might indicate a leak in the tank, a paste that changes color when it contacts water can be placed on the stick. This water detection paste is inexpensive and can be bought from most heating oil companies.

3. Pump any remaining oil from the tank and dispose of it properly.

Completing this step as soon as possible may prevent contamination of soil and groundwater. However, this is not a long-term solution by itself. Abandoning an empty tank in the ground on the property can leave the owner open to the liability of cave-ins or the migration of leaked oil into groundwater.

4a. Remove and dispose of the tank.

This step benefits the owner more than decommissioning the tank in place (step 4b) for several reasons.

• Soils contaminated by a leaking tank can be located and cleaned up.
• It is easier to take soil samples when a tank has been removed. It is recommended that a soil sample(s) be taken as an unbiased means to prove a clean closure even if there are no odors or visible signs of a leak.
• Many lending institutions and buyers require removal of unused tanks as a condition of sale. It is a good idea to take photographs of the removal process for the record. Also, the owner should find out where the tank is being disposed. It should not be stored at the site. The owner should obtain documentation that the tank was disposed of properly. To be recycled as scrap metal, the tank must be properly cleaned out, the sludge should be treated as hazardous waste, and a hole should be cut in the end so the scrap metal dealer sees no sludge is left.

4b. Decommission the tank in place.

Check with the local fire marshal and/or building department for permitting requirements and for approved materials to fill the tank. Keep in mind the following points before selecting this method.

• The owner may be required, by the lender and buyer, to have the soil beneath the tank tested.
• Because getting soil samples from underneath an underground tank is difficult, this may cost more than removing the tank.
• The tank must be pumped out and cleaned before it is decommissioned in place. All oil, rinse water, and sludge must be disposed of properly.
• Local ordinances may not allow you to abandon the tank in place.
• A tank that has been filled in place will be difficult to remove at a later date.

5. Test soils for contamination.

Check with local building and fire departments to determine if soil testing is required in the jurisdiction

where the tank is located. Under the Model Toxics Control Act, if contamination is present these tests are required to prove that an adequate clean up took place. Even if a leak is not detected, soil tests are beneficial to the owner because they are a more objective way to legally document that the site is not

contaminated. The contractors who remove or decommission tanks in place can collect soil samples and have them analyzed.

6. Clean up contaminated soils.

The state Model Toxics Control Act (WAC 173-340) sets requirements for cleaning up contaminated sites.

Contaminated sites should be reported to the State Department of Ecology at (425) 407-6000. How you handle contaminated soil depends on the amount of contamination.

7. Document everything.

Keep a file of permits, lab results, disposal records, photographs, and reports from contractors regarding any cleanup

Finding a Laboratory for Soil Testing

Several laboratories in the state perform the appropriate test for petroleum contaminated soil.

It is recommended that an experienced, unbiased person collect samples. If owners elect to collect

the soil samples themselves, they should call the laboratory for specific instructions regarding the

sampling procedure. Prices vary widely. Therefore, property owners should obtain several quotes or bids before selecting a laboratory.

Some important questions to ask laboratories:

• Are they familiar with the recommended method for testing petroleum contaminated soil?
• Do they perform it regularly?
• Can they provide the names and numbers of recent customers as references?
• What are their sampling and shipping procedures?
• Do they provide the sample container?
• How long will it take to get the results?
• What type of documentation do they provide?
• Do they collect soil samples?
• Which laboratory do they use for the analyses?
• Where will the tank, oil, and contaminated water from rinsing out the tank be disposed? Is that disposal site insured?
• What documentation, labeling, and other paperwork are provided? You should receive documentation of disposal of the tank, a copy of the lab results, documentation that the soil samples were handled properly, a copy of any permits required, and documentation of the disposal and/or treatment of any wastes.

ESN Northwest Libby Environmental

Lacey Olympia

Attn: Michael Korosec Attn: Hillary Lewis

(360) 459-4670 (360) 352-2110

Department of Ecology

Accredited Lab Website Link

Local Government Regulations

Unincorporated Thurston County

• Building Dept Phone #: 360-786-5490
• Contacting fire dept not required
• *Permit and site plan is required
• *Inspection is required
• **Soil test required: Yes, if inspector detects contamination or if tank is decommissioned in place


• Building Dept Phone #: 360-278-3525
• Contacting fire dept not required
• *Permit and site plan is required
• *Inspection is required
• **Soil test required: Yes, if inspector detects contamination or if tank is decommissioned in place


• Building Dept Phone #: 360-491-5642
• Contacting fire dept not required
• *Permit and site plan not required
• *Inspection not required
• **Soil test required: Only if tank is leaking


• Building Dept Phone #: 360-753-8314
• Also contact fire dept at 360-753-8348
• *Permit and site plan is required
• *Inspection is required
• **Soil test is required


• Building Dept Phone #: 360-446-2265
• Contacting fire dept not required
• *Permit and site plan is required
• *Inspection is required
• **Soil test required: Yes, if inspector detects contamination or if tank is decommissioned in place


• Building Dept Phone #: 360-264-2368
• Contacting fire dept not required
• *Permit and site plan not required
• *Inspection is required
• **Soil test required: Yes, if inspector detects contamination


• Building Dept Phone #: 360-754-4180
• Contacting fire dept not required
• *Permit and site plan is required
• *Inspection is required
• **Soil test required: Yes, if inspector detects contamination


• Building Dept Phone #: 360-458-8407
• Contacting fire dept not required
• *Permit and site plan is required
• *Inspection is required
• **Soil test required: Yes, if inspector detects contamination
• *Obtaining the proper permit is the responsibility of the homeowner, not the contractor. However, many contractors include this process in their service. If your contractor obtains the permit, make sure you receive a copy.
• **Soil tests are always strongly recommended because they are the only way to legally document that your site is not contaminated.

More Questions? Call:

Thurston County Environmental Health

(360) 754-4111 (360) 754-2933 TDD

Environmental Health


This article was taken from the March 2013 issue of Inspections Insider by Larry Stamp with Cameo Home Inspection Services. Click here to view the original article.

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