Potential Underground Oil Tank Identified During Exterior Tank Sweep

During a recent property inspection, I performed an exterior oil tank sweep using a magnetometer and metal detector around the foundation. The instruments produced elevated and consistent readings, indicating the possible presence of buried metallic objects near the home.

While magnetometer and metal detector readings alone do not confirm an underground storage tank, the signal pattern was strong enough to warrant further investigation.

What Was Found Inside the Basement

After identifying the elevated readings outside, I inspected the interior of the basement for corroborating evidence. Inside, I observed older fuel oil lines penetrating through the foundation wall, consistent with historic oil-fired heating systems.

These lines appeared inactive, but their presence is significant. In many older New Jersey homes, fuel oil lines entering through the foundation are commonly associated with former underground oil tanks, even if the tank itself is no longer visible.

When exterior instrument readings align with interior fuel line evidence, the likelihood of a prior or existing underground oil tank increases substantially.

Why This Is Important

Underground oil tanks can pose serious financial and environmental risks, including:

• Soil contamination from leaks or corrosion

• Potential groundwater impact

• Costly remediation if contamination is discovered

• Delays or complications during real estate transactions

  
  

Even tanks that were taken out of service decades ago can still leak. In many cases, homeowners are unaware a tank ever existed until an inspection or transaction brings it to light.

New Jersey Requirements and Considerations

In New Jersey, underground oil tanks are a major concern during property sales and refinancing:

• Sellers are typically required to disclose known underground oil tanks

• If a tank is confirmed, proper abandonment or removal documentation is often required

• If contamination is found, state-regulated remediation may be necessary

• Lenders and buyers may require confirmation that no underground tank is present

New Jersey does offer programs to assist with remediation costs in certain situations, but eligibility depends on documentation and timing. Discovering a tank before closing provides significantly more options than discovering one afterward.

What Homeowners Should Do Next

When an oil tank sweep produces elevated readings and interior fuel lines are observed:

1. Do not assume the tank was removed

2. Consider follow-up investigation, such as:

   • Ground-penetrating radar (GPR)

   • Targeted test pits performed by a licensed contractor

3. Gather any available documentation from prior owners

4. Consult professionals experienced with New Jersey oil tank regulations

Early investigation can prevent unexpected costs and delays later.

Final Thoughts

Oil tank sweeps are not just about detecting metal — they are about reducing risk. When exterior readings and interior evidence tell the same story, it’s important to take the findings seriously and proceed carefully.

If you’re buying, selling, or renovating a home in New Jersey and suspect a past oil tank, a professional tank sweep and follow-up evaluation can save significant time, money, and stress.