7 Things to Know if Your Underground Oil Tank Is Leaking

‍Key Takeaways:

• Early detection is critical to prevent costly damage. Watch for warning signs like oil odors, dead vegetation, sudden fuel usage spikes, or oily sheens on water to catch leaks early. Quick action limits cleanup costs, reduces health risks, and prevents major environmental damage.
• Leaks pose serious environmental and health risks. A leaking tank can contaminate soil, groundwater, and indoor air with toxic chemicals like benzene. These pollutants threaten your family’s health and require immediate professional testing and remediation.
• Legal and financial responsibilities fall on the homeowner since they are legally responsible for reporting leaks and covering cleanup costs, even if they are unaware of the problem. Delays can lead to heavy fines, and insurance often excludes underground oil tank leaks.
• Professional inspections and preventive measures protect your future. Certified contractors can accurately detect leaks and recommend safe remediation options. Regular inspections, leak detection systems, or switching to above-ground tanks help prevent future problems and protect property value.

An underground oil tank can provide convenient storage for heating oil, but it also carries serious risks, especially if it begins to leak. Leaks can contaminate soil and groundwater, harm your health, and lead to costly cleanups. If you suspect a leak, acting quickly is critical.

These tanks are often buried out of sight, which means problems can go undetected for months or even years until significant damage has already occurred. A slow leak can release hundreds of gallons of heating oil into the ground, seeping into surrounding soil and traveling to nearby water sources. This contamination not only threatens the environment but can also create strong odors and dangerous toxic fumes that infiltrate your home. 

Cleanup costs can escalate rapidly, especially if the leak reaches groundwater or spreads to neighboring properties. Here are 7 essential things you need to know if your underground oil tank is leaking, and how T.H. Malloy & Sons, Inc., a trusted name in oil tank services, can help you protect your property and your peace of mind.

1. Know the Signs of a Oil Leak

Early detection can prevent a minor issue from becoming a major disaster. Warning signs of a leaking underground oil tank include:

• Persistent oil odors near the tank or inside your home are often one of the first warning signs of a leak. These smells occur when heating oil vapors escape from a compromised tank or contaminated soil and seep into the air around your property.
• Unexplained patches of dead or discolored vegetation can signal that leaking heating oil has saturated the surrounding soil. Oil contamination disrupts the natural balance of nutrients and oxygen in the ground, causing grass, shrubs, or plants to wither even when the rest of the yard appears healthy. These spots may expand over time as the leak spreads, creating irregular patterns of damage that are difficult to reverse without remediation.
• An oil sheen on puddles, streams, or nearby water sources is a clear indication that leaking fuel has migrated beyond the tank area. This thin, rainbow-like film forms when heating oil rises to the surface of standing water or flows into natural waterways.
• Sudden spikes in heating oil usage can indicate that fuel is escaping from the underground tank rather than being used by your heating system. If your consumption rises unexpectedly despite normal weather conditions and household habits, it may mean oil is leaking into the surrounding soil. 

2. Understand the Environmental and Health Risks

A leaking underground oil tank can cause extensive environmental and structural damage if not addressed quickly. It may release harmful chemicals into the soil, groundwater, and even indoor air, creating serious health effects and costly cleanup challenges, such as:

• A leaking underground oil tank can contaminate drinking water and groundwater by allowing harmful chemicals to seep deep into the soil and water table. Once oil reaches these sources, it can introduce toxic substances like benzene and other hydrocarbons, making the water unsafe for consumption or everyday use. 
• Leaking heating oil can pollute soil, making it unsafe for landscaping or gardening by saturating the ground with toxic hydrocarbons. Contaminated soil can hinder plant growth, kill existing vegetation, and pose health risks if touched or inhaled. 
• A leaking underground oil tank can release harmful vapors that affect indoor air quality, allowing fumes to seep into basements, crawl spaces, or living areas. These vapors may contain toxic compounds such as benzene, which can cause headaches, nausea, respiratory issues, and long-term health risks with prolonged exposure

3. Be Aware of Legal and Insurance Responsibilities

Homeowners are typically legally responsible for leaks from an underground oil tank because of the Oil Pollution Act, even if they were unaware of the problem. Important considerations include:

• Many state and local regulations require immediate reporting of leaks to prevent environmental damage and protect public health. Homeowners are often legally obligated to notify environmental authorities as soon as a leak is suspected or confirmed, even before cleanup begins. And local regulations requiring immediate reporting of leaks
• Delaying action on a leaking underground oil tank can result in potential fines and penalties from environmental and regulatory agencies. These costs can escalate quickly, especially if the leak causes significant soil or groundwater contamination that impacts neighboring properties. Staying proactive with upkeep, such as following the instructions on how to maintain home heating system, can help prevent leaks and reduce the risk of costly fines or insurance complications.
• Homeowners often face limited insurance coverage, as many standard policies specifically exclude damage from underground oil tank leaks. This means property owners may be responsible for the full cost of cleanup, soil remediation, and tank removal, which can be substantial.

4. Schedule Professional Testing and Inspection

Only certified environmental contractors can accurately detect and confirm leaks because they use specialized equipment and testing methods that meet strict regulatory standards. Along with oil tank testing, these professionals can assess surrounding soil and groundwater conditions to pinpoint contamination and recommend the safest remediation plan.

• Soil sampling to identify contamination involves collecting and analyzing soil around the underground oil tank to detect the presence of leaked fuel or hazardous chemicals. This process helps determine the extent of pollution, guiding the necessary cleanup and remediation plan.
• Tank tightness testing to confirm leaks is a specialized procedure that measures pressure changes inside the underground oil tank to detect even the smallest breaches.  Scheduling a Comprehensive Heating Inspection can help ensure that your entire heating system is running at peak performance and that it’s not affected by your oil tank. 
• This test helps determine whether the tank is losing fuel and pinpoints potential weak spots before major contamination occurs.

5. Understand Cleanup and Remediation Options

If your underground oil tank is leaking, cleanup may involve a series of specialized procedures to remove contamination and prevent further damage. This can include professional tank removal, soil excavation, groundwater treatment, and proper disposal of hazardous materials to restore your property to safe conditions.

• Tank removal or decommissioning is the process of safely eliminating an underground oil tank that is leaking, damaged, or no longer in use. During cleanup or after tank removal, it’s also wise to familiarize yourself with common heating system problems to spot potential issues that could affect the efficiency and safety of your home’s heating equipment, such as an oil tank.
• Soil excavation and disposal of contaminated earth involves digging up and removing soil that has been polluted by leaking heating oil. This process ensures that toxic substances are safely removed from the site to approved disposal or treatment facilities, preventing further environmental damage.

6. Explore Financial Assistance Programs

Some states and municipalities offer grants, low-interest loans, or reimbursement programs to help cover oil tank removal or remediation costs.
Your options may include:

• State environmental agency grants are financial assistance programs designed to help homeowners cover the costs of underground oil tank removal, soil cleanup, or leak remediation. These grants can significantly reduce out-of-pocket expenses, making it easier to address contamination quickly and responsibly.
• Local homeowner assistance programs offer financial support or low-interest loans to help residents manage the costs of underground oil tank removal and environmental cleanup. Municipalities or county governments often sponsor these programs to encourage prompt action and prevent widespread contamination.

7. Prevent Future Problems

Once cleanup is complete, prevention becomes the key to protecting your property and avoiding future leaks. Important steps to consider include regular inspections, installing leak detection systems, and upgrading to safer heating solutions to ensure long-term safety and efficiency.

• Regular inspections of any remaining tanks are essential for detecting early signs of corrosion, leaks, or structural weakness before major problems develop. Routine checkups can identify issues such as rust, cracks, or shifting soil that may compromise the tank’s integrity.
  
  
• Upgrading to above-ground tanks or switching to alternative energy sources provides a safer and more environmentally friendly solution for home heating needs. Above-ground tanks are easier to inspect, maintain, and replace, while options like natural gas or electric heating eliminate the risk of underground leaks.
  
  
• Installing leak detection systems for early warning helps identify even small releases of oil before they cause significant soil or groundwater contamination. In addition to monitoring your oil tank, homeowners using propane should also review how to detect a propane leak to stay informed about other potential fuel-related hazards.

Related blog: Tips to Safely Detect Propane Leak at Home

Contact T.H. Malloy & Sons,Inc for Oil Tank Inspections

If you suspect your underground oil tank is leaking, don’t delay. Contact T.H. Malloy & Sons,Inc,  today to schedule a professional inspection and cleanup. Protect your home, your health, and your investment.

Frequently Asked Questions

How can I tell if my underground oil tank is leaking?

Common signs include persistent oil odors, dead or discolored vegetation, sudden spikes in fuel usage, or an oily sheen on nearby water sources. These indicators mean you should contact a certified environmental contractor immediately for professional testing.

Who is responsible for the cleanup costs if a leak is found?

Homeowners are typically responsible for all cleanup and remediation costs, even if they were unaware of the leak. Insurance policies often exclude underground oil tank leaks, so it’s important to act quickly to limit expenses and potential fines.

What steps are involved in cleaning up a leaking underground oil tank?

Cleanup may include professional tank removal, soil excavation, and groundwater treatment to remove contamination and restore safety. Certified contractors follow strict environmental regulations to ensure proper disposal of hazardous materials.

How can I prevent future underground oil tank leaks?

Regular inspections, installing leak detection systems, and upgrading to above-ground tanks are the most effective preventive measures. Switching to alternative heating sources like natural gas or electric systems can also eliminate the risk of underground leaks.