Underground oil tanks were widely used decades ago to store heating oil, particularly in older residential and commercial properties. Over time, many of these tanks corroded, leaked, or were abandoned without proper decommissioning. One of the biggest threats associated with these aging tanks is soil contamination. Contaminated soil can affect property value, create environmental hazards, and lead to expensive remediation requirements if ignored.
If you suspect that a buried tank exists on your property, or you notice unusual changes in your yard, the question becomes: How do I check if my soil is contaminated by an underground oil tank?
This in-depth guide explains the warning signs, the testing methods, and the steps you should take to protect your property, along with the role of professional support from an oil tank removal service.
1. What Causes Soil Contamination from Underground Oil Tanks?
Underground oil tanks, especially those made of steel, naturally begin to deteriorate after several decades. As rust and corrosion progress, the tank weakens and eventually leaks. Once oil penetrates the surrounding soil, it spreads quietly and often goes unnoticed until the contamination becomes severe.
The most common reasons underground tank leaks occur include:
-Age-related tank deterioration
-Corroded fuel lines or fittings
-Improper tank installation
-Abandonment without proper removal
-Spills during fuel deliveries
-Previous owners concealing tank damage
Since contamination spreads slowly and silently, soil testing becomes the only reliable way to confirm the presence and severity of the issue.
2. Early Warning Signs Your Soil May Be Contaminated
A leaking underground oil tank may not show obvious symptoms at first. However, several warning signs can indicate potential contamination:
Strong Fuel or Chemical Odor
A persistent petroleum smell in your yard, basement, or near the suspected tank area is often a clear indicator that oil has seeped into the soil.
Sudden Death of Grass or Vegetation
If patches of grass turn yellow, die, or fail to grow despite proper watering, the soil may contain leaked hydrocarbons.
Oily Residue or Sheens on Water
Oil migrating upward through soil may create dark, oily spots or rainbow-colored sheens on standing water after rain.
Sinking or Depressed Ground
A collapsing tank can create soft soil, dips, or sinkholes near the buried structure.
Discovery of Old Pipes
Fill pipes, vent pipes, or metal caps near foundations often indicate the presence of an underground oil tank.
These signs help identify a potential problem, but they are not enough to confirm contamination. Professional testing provides accurate verification.
3. How to Check If Your Soil Is Contaminated
If you are concerned about a buried oil tank, follow these essential steps to assess whether contamination has occurred:
Step 1: Confirm the Presence of an Underground Tank
Many property owners are unaware that a tank exists. To identify one:
-Review property inspection reports
-Ask your municipality for historical property documents
-Search for visible pipes or tank caps
-Use metal detection or ground-penetrating radar
If a tank is confirmed, proceed with a more detailed evaluation.
Step 2: Conduct a Visual and Physical Assessment
Inspect the surrounding area and note:
-Persistent odors
-Areas of dead vegetation
-Discolored soil
-Surface oil spots
-Unusual ground settling
These observations help professionals understand the extent of the potential contamination.
Step 3: Schedule Professional Soil Testing
Soil testing is the most accurate and essential step in determining whether oil has leaked into your property. Environmental specialists take soil samples from multiple depths around the tank to detect petroleum hydrocarbons.
Soil testing helps determine:
-Whether contamination exists
-How far oil has migrated
-Whether groundwater is affected
-What level of remediation is needed
Without this scientific analysis, you cannot confidently assess the true condition of your soil.
Step 4: Request a Detailed Tank Leak Assessment Report
Once testing is complete, you will receive a report that includes:
-Lab test results and hydrocarbon levels
-Confirmation of contamination
-Environmental impact findings
-Recommended actions for cleanup and tank removal
This documentation is extremely valuable during property transactions, insurance claims, and state-regulated cleanup programs.
Step 5: Contact an Oil Tank Removal Service
If the tank is leaking—or even if it’s simply old—removal is strongly recommended. Professionals will:
-Excavate the tank safely
-Remove contaminated soil
-Dispose of hazardous materials properly
-Backfill and restore the area
-Provide legal documentation for compliance
Attempting this yourself is dangerous and illegal in many states.
Step 6: Conduct Post-Removal Soil Monitoring
After remediation, professionals may advise future monitoring to ensure:
-No new contamination occurs
-Soil conditions remain stable
-Environmental compliance is maintained
This is especially important for properties undergoing construction or landscaping.
4. Why Professional Soil Testing Matters
While surface indicators can suggest contamination, only soil testing provides accurate evidence. It also helps identify hidden risks such as:
-Groundwater contamination
-Vapors entering the home
-Long-term environmental hazards
-Structural risk to foundations
Early testing is far cheaper than emergency remediation. It also ensures your property maintains its resale value and meets environmental safety standards.
5. The Risks of Ignoring a Leaking Underground Oil Tank
A leaking tank should never be ignored. If left unchecked, it can cause:
● Significant Property Damage
Oil can compromise soil quality, kill plants, and seep into basements.
● Environmental Pollution
Hydrocarbons can travel through soil and contaminate nearby water sources.
● Expensive Remediation Costs
The longer contamination spreads, the deeper and more costly the cleanup becomes.
● Legal Consequences
Many states require prompt reporting and cleanup. Failure to act can lead to penalties and mandated remediation orders.
● Reduced Property Value
Homes with unresolved contamination issues are difficult to sell and may lose market value.
6. How Professionals Detect Underground Tank Contamination
Certified environmental specialists use advanced equipment and proven methods to diagnose contamination accurately, including:
-Ground-Penetrating Radar (GPR)
-Soil boring and sampling
-Hydrocarbon laboratory analysis
-Groundwater monitoring wells
-Environmental impact assessment
These techniques ensure precise testing and help determine the safest and most effective remediation plan.
FAQs
1. How do I know if a tank exists under my property?
Look for vent/fill pipes, check property records, or request a GPR scan.
2. Can I check soil contamination myself?
No. Home kits are not accurate for petroleum detection. Professional testing is required.
3. How long does soil testing take?
Sampling takes a few hours; laboratory results may take 3–7 days.
4. What should I do if contamination is found?
Hire a certified oil tank removal and environmental remediation provider immediately.
5. Is tank removal mandatory?
If a tank is leaking or abandoned, many states require its removal and proper remediation.
Summary
Checking whether your soil is contaminated by an underground oil tank requires a combination of visual inspection, professional evaluation, and scientific soil testing. Early detection protects your property’s value, prevents environmental damage, and ensures compliance with state regulations. When contamination or tank damage is confirmed, expert removal and remediation are essential for restoring safety and preserving long-term property health. For reliable, compliant, and professional support, you can count on Simple Tank Services.