So many people continue to use Underground Storage Tanks (USTS), with the belief that the tank is in 100% working order, meaning no leaks.    How do you know if your tank is leaking -   Ninety-nine percent of the time you have no idea if your underground oil tank is leaking.   Let's be real, your smoke detector chirps when the battery is low, does your oil tank have an alarm or notification system?

Case in point, the following photos show a tank that is in use and was being replaced with an Aboveground Storage Tank (AST) for a future real estate transaction.  The photo below shows the tank fill pipe poking out of the ground about 18" high and in front of the rear stairs, pretty obvious a tank is present.

This tank gets removed, and we find that the tank was filled with oil, this oil was going to get transferred to the new AST.

So again, tank was being removed proactively, no signs the tank was leaking.  Tank gets removed, soils are a course sand.

Here is the tank out of the ground after removal.  What you need to note on the tank is the wetness on the top of the tank in the photo.  To you you see the top, but it is the bottom of the tank.   The wetness on the bottom of the tank is actually oil.   Note how soils are sticking to the tank.

So if you were on site and wiped you hand across the wetness, it would feel slick and smell oily.  Almost dead center of the photo below you can see the corrosion hole in the tank, almost big enough to put your finger through.  Now this hole was not always so large, it started as a pin hole, working through the tank as corrosion removed layer after layer of steel.  Once the hole advances through the tank shell, oil drips out, saturating soils, causing the soil to bind to the tank and form a plug that slows the oil leak, but does not stop it.

This tank, which was holding most of the oil, was slowly dripping oil for years.  The owner had no idea, because the hole was at the bottom of the tank, so water would not enter the tank and shut off the heater, the oil loss were drips, not dozens of gallons a day.  If you lost 70 or 10 gallons, you would notice, ounces a day, goes unnoticed.  Don't believe me?  Answer these questions.

• How many gallons of gas are in your car right now?
• When did or does the warranty on your car expire?  Oh the expiration of the warranty on your oil tank?
• Wait, does your oil tank have a warranty?
• How old is the tank?  Did the old owner replace the tank?  If so when?  Did you even ask?
• Do you have any salad dressing in the refrigerator that have expired?

Not trying to be funny, just making a point, that you don't pay attention to the mundane.   When your computer hard drive crashes, its a catastrophe,   well the same goes for your oil tank.  Rust never sleeps and the majority of tanks are well out of warranty and even farther out of the engineered design life expectancy.

Tanks are out of sight out of mind and people think they have a handle on the tank being in good condition, they think oil usage is normal no water in the tank are all signs the tank is not leaking.  Well water enters only of there is a hole in the top of the tank that would allow water to drain into, oil usage you only notice sudden drops in liquid, which is not the norm for a tank leak.  To be fair commercial tanks have expensive electronic leak detection systems, residential tanks do not.  To think you have a grip on how much oil your using, it giving yourself a little too much credit.

Some advice for knowing if your tank is at risk of leaking.

• Is the tank under warranty?
• Was the roof replaced?  If so the tank should have been replaced?
• Are you placing anything in the tank to prevent corrosion from the inside?
• Do you get the tank leak tested every year?

A no to any of these questions means you should replace the tank.  You can install a new Aboveground Tank that has a 30 or 40 year warranty, yes they cost money, but less than having to remediate a tank leak.  Tank leaks cost tens of thousands of dollars.

Call the experts   888-301-1050

Tank sweeps, or tank scans are an evaluation of a property for a buried Underground Storage Tank (UST). Unfortunately, these sweeps/scans have become generic to so many and people are unaware of the limitations, between both the companies providing the scan and the technology used.

                             Metal Detector                                      Vs.                         Ground Penetrating Radar

Best price, means least expensive technology (metal detector), for example would purchase a 5SE phone vs. the IPhone 12? Maybe for your young kids, but not for you. The best  utilized  technology for locating underground oil tanks is Ground Penetrating Radar (GPR).                     

An example of using a metal detector as opposed to a the Ground Penetrator Radar - Curren was provided a report from a client who asked for an underground oil tank removal. Oil tanks were discussed in the report. The tank locatoror who provided the tank scan with noted the following: “While conducting the oil tank scan it was noticed that there is the possible presence of an oil tank at the front of the home. This was noticed using Schonstedt magnetic locator which detects the magnetic field of ferromagnetic objects. The object that was detected is 3ft x 5ft. After detecting this object a 4 ft probe was inserted into the ground in this area and we detected a object about 3 ft below the surface. A qualified oil tank removal company should further evaluate to determine the size and depth of the possible tank. This company should also conduct proper soil samples to determine if a leak is present at the possible tank.” Several photographs were also included to indicate the meter utilized, and the areas investigated. 

Instead of doing another scan with the Ground Penetrating Radar, the client asked Curren to remove the said underground oil tank found with the metal detector. Curren mobilized equipment and labor to remove the #2 fuel oil UST (subject tank). Curren excavated in the area identified in the Tank Inspection report to a depth of 9’.

No tank was located. Curren then excavated toward the residence additionally to 9’. No tank was located. Curren inspected the basement for copper lines and no copper lines were found.

Conclusions & Recommendations

The conclusions are based upon the review of available information, field observations and test results obtained during this project. Curren Environmental, Inc. does not assume any responsibility for using this report for purposes other than those indicated in the specific area investigated.

Based on onsite observations, the areas indicated in the report were investigated, no underground storage tank was located in this area. The client, ended up spending a large sum of money to remove an oil tank that was not there.  

What is a metal detector? "Metal detectors use electromagnetic fields to passively or actively detect the presence of metallic objects. Passive detection measures the changes in the Earth's magnetic field caused by an object."  The photo below shows some debris, that debris was located by a metal detector.  Curren was contracted by client to remove the "underground oil tank".  The metal detector tank sweep found debris, not an oil tank. 

What is a ground penetrating radar system? Learn more here.

What  happens when a home inspection finds a possible underground oil tank?

A common request our office receives regarding a tank sweeps.

1. The property owner is unclear how the suspect tank was found.  Was it found with a Metal detector, or  Ground Penetrating Radar or both? (both GPR and a metal detector would be best) The solution would be having the owner receive a copy of the Tank Sweep Report so they would have a baseline regarding what they found and where. Yes, every professional service should come with a report, no report, then question how professional the service was.
2. The property is over 70 years old, so while the owner has no knowledge that there was an oil tank, they also have no documentation that there was not an oil tank. A 70 year old property most likely had oil heat at one point in time as oil was very popular in the past and other fuel sources such as natural gas was not commonly available or financially appealing until the 1970's.
3. The tank scan found a buried object, presumably metal. If only a metal detector was utilized, you can't say 100% if the metal found is a tank as metal detectors detect metal and properties have all sort of buried metal. Metal can be in the soil naturally, you could have buried debris, buried metal pipes or surface metal (like a fence) that distracted the metal detector and have a false buried metallic signature reading. Happens all the time. A metal detector on a sandy beach is great it will find buried metal, likely a bottle cap, but people hope for coins or expensive jewelry. People paying a couple hundred dollars for someone to use an $800 metal detector to find a tank are also helpful.

The guy in shorts, is using a $900.00 metal detector and found a suspect tank in the front yard.

When you scan for a tank, the more expensive the equipment the better.   GPR (Ground Penetrating Radar) costs tens of thousands of dollars because it has the technology to do the job.

 Effective Oil Tank Scan or Oil Tank Sweeps like on commercial sites would use GPR as it will                            provide a signal (image) of buried objects.

The signal above shows the underground oil tank. 

Purchasers of commercial properties are more aware of the liability associated with leaking USTs (Hundreds of thousands of dollars) compared to a residential home buyers (Homeowners think a few thousand dollars is a lot.) So on the commercial side of real estate tank sweeps are completed with GPR, not metal detectors. Most environmental consultants that perform tanks weeps will use GPR and discount the cost for residential sites. Nobody wants to see someone buy a house and find a $50,0000 cleanup is required.

What if a buyer finds a suspect tank?

This is a really hard question because it relies so much on the quality of the tank sweep.    If they used GPR, if the property is likely to have had an oil tank (older the home, the more likely) and if the buried anomaly has the signature of a tank.  Well then you have to excavate and confirm that object is an oil tank.

Who pays for the oil tank removal?

Owner will pay 98% of the time as finding a hidden oil tank is a defect that needs to be addressed.

Do they have buried oil tanks at the beach (shore)?

If the home wanted heat, then yes homes along the coast and on islands had buried oil tanks.  Oil was king up until the late 1970's in New Jersey.  The photo below is of a home we scanned on a barrier island.  Many older beach houses eventually converted to natural gas, as gas could also  fuel the stove, dryer,  hot water heater etc.   After conversion to gas, it was not uncommon that the tank was just left in the ground.  So short answer beach houses had oil tanks.

What if a suspect tank is found and we don't believe its a tank?

Short answer prove your opinion right and dig it up and verify its not a tank.

What is the best tank sweep?

Using Ground Penetrating Radar is the best technology for finding buried tanks at properties, period.  Can you use a metal detector to verify a GPR signal that identified a tank?  Sure, always verify the object is metal.  GPR can't penetrate metal so when a GPR sweep pings a tank, it means the radar can't penetrate the object (likely a metal tank) but there are buried concrete tanks.  Metal detectors can verify an object is metal, but a metal detector  should not be used to be your sole technology

People are different. Homes are different. Not all cars are the same. 

What about Tank Sweeps?

The generic term, "Tank Sweep" gives you two distinct approaches to perform a sweep and the quality level are polar opposites.

First off, the purpose of having an Oil Tank Sweep done in NJ, PA and DE is to detect for the presence of an intact, underground oil tank. The reason you want to identify an underground tank before you buy a property, is to avoid the potential of paying for a contamination cleanup from a leaking tank. In our world a small clean up is under $15,000, more extensive cleanup start around $75,000 and go into the $100,000's.     You can see why a quality tank sweep is important. 

So when you are faced with tens of thousands of dollars to address a tank leak, go with the best approach which is using GPR (Ground Penetrating Radar) for a tank sweep.  The technology will cost you a few hundred dollars more than someone using a metal detector, but the quality of the two approaches is night and day.  

GPR sends radio waves in the ground which can reflect off of a metallic object giving the technician an image.   Certain images are tanks, some are pipes, some are debris.

There are dozens of people who have bought an $800.00 metal detector and work out of their home and do tank scans.   If only a tank was the only metal on a property, then these people would be super geniuses, but alas, metal is abundant in the ground, naturally in some soils, rocks, pipes, rebar, buried debris, above ground what do you have that doesn't have metal?  The point being you can't use cheap technology for such an important service.

To top it off, these one person bands,  as they don't remove tanks, so if you find a tank, now you have to find a company to remove it,  In a real estate transaction delays are bad.

The icing on the cake is we have been hired to remove tank found by the metal detector sweep person to only dig up not an oil tank. Really, we find no tank about 65% of the time. 

Five Tank Sweep Tips.

1. Ask the selling about prior oil heat.  In NJ they are supposed to disclose it, in PA they are not.  In every state we work the owners have  not been 100% honest with a tank disclosure.   I say this because we do thousands of tank sweep, tens of thousands tank removals so we touch more properties than pretty much any company in the area (we have been do this work for decades.)

How are owners not honest about an oil tank?  Well after we find one, many owners suddenly have tank paperwork or now remember yes there was a tank on the property.  This is 100% accurate statement

So always ask in writing about what they know regarding prior oil usage at the site.  People lie about USTS (Underground Storage Tanks) and ASTs (Aboveground Storage Tanks).   

2.  Look at the neighborhood, are there houses with oil heat?  Bingo do a scan.

3. Don't ignore ASTs (Aboveground Oil Tanks), many AST's replaced USTs.

4. If a property had a tank removed, don't assume that was the only tank.  Do a tanks weep, many sites had 2 tanks.

5. Check with the town regarding any permits for tank replacement, filling or removal.

What if a tank sweep finds an oil tank?

At Curren we provide a cost to remove and test the tank.  Tested clean tanks are not a problem. Many owners will hire us because they need to address the tank they didn't know about and well, we do this a lot, are competitive,  experienced and work in our client's best interest.  If we can save a client money we do, its in our DNA.

That said, don't run away from a property after you find  a tank (the next property may have one), rewove and test it.  Of course if the property owner refuses to address the tanks, well in that case, run away (walking isn't fast enough).

Bottom line when you find a tank, you want it removed and tested, and remediated if it leaks.  It truly doesn't matter to us if we remove the found tank or not.  Hey many property owners are mad we found a tank, true. We just want the tank removed and tested so our client doesn't have to deal with that expense. 

Understand the process of a tank sweeps and what happens after a tank sweep.

The best situation regarding a tank sweep is finding a tank, therefore it can be removed and soil tested to prove that no soil remediation (cleanup) is required.

A hidden or an underground oil tank is a major financial liability when buying a home, because rust never sleeps and oil leaks from the tank. Soil remediation from leaking oil tanks can easily cost into the tens of thousands of dollars.   A tank sweep of any property is always recommended unless you can document the site never had oil heat, unfortunately older homes had oil heat since it was the only option after coal use.

Should I buy a house with an underground oil tank?

An underground oil tank can make a home harder to sell or worth less to a potential buyer, how does a $32,000.00 oil tank cleanup ding the value of a home?  How about a cleanup over a $100,000?  They happen as well.    A known oil tank can also increase the chances of complications with getting to the closing table and the home sold. Mortgage lenders are wary of buried oil tanks and may refuse to lend on a home with an underground tank.  Appraisers and insurance companies may also flag the tank as a liability and want it addressed.

What is the life expectancy of an underground oil tank?

The average life of a UST is about 20 years (if you bought a middle of the road tank today, that is your warranty.) However, with the tank buried, other factors will influence the lifespan of underground tanks, including the gauge of its steel, geology, corrosivity of the soils, etc. 

FACT:  most tanks were used past their design life expectancy and left in the ground unused past their life expectancy as well.

How do you manage the liability with an oil tank?

The liability of an oil tank pertains to leaks that occur and the state mandated cleanup of the oil leaks.   The best situation regarding a tank sweep is finding a tank so it can be removed and tested to prove that no cleanup is required.

What happens if the tank sweep does not find a tank but points to a tank being removed?

This is not your best scenario because now you do not know if the tank leaked or where the tank was located. Clearly not finding a tank means your investigative work is not complete, because you do not know if the tank leaked.   Tank sweeps cannot find removed tanks, so you are tasked with historical research on who removed the tank.    So you will be tasked with doing soil borings with laboratory testing to ensure there is not residual oil contamination from the removed tank. 

The best approach is to assume the tank leaked until proven otherwise.

Bottom line you have to make an effort to find where the tank was located.   Sometimes owners get a conscience  and will admit that a tank was removed, they just did not think that knowledge was relevant at that time. Sometimes a tank sweep can point to a likely area of where the tank was located.

We had a case where an owner removed their own tank in the backyard without a permit.   They eventually were going to sell the home and did not want the tank as an issue. The final cleanup was around $40,000. Someone admitting to a bad thing is not common, but we do see it happen.

Sometimes we can find the tank grave, other times we have to do a grid of soil borings in the suspected area to try and find the tank grave and to test soil.

Tank sweeps that point to a removed tank will lead to soil testing in the area of the removed tank, unless of course a report exists of the tank removal with testing and a clear statement that the tank did not leak. Best case you find no contamination, worst you find contamination, which is reportable to the state and further work would be necessary.

The following two photos show where a tank was removed 20 years ago, so we had to do soil borings to evalaute for oil.  One of the two sites had oil contamination, do you know which one?

Be aware there have been many tanks that were removed, that leaked and were not cleaned up. Owner hoped no one will look or test the area.  If you don't have  a report that includes laboratory data saying the tank did not leak, you don't have what you need to remove the liability of the tank.

What about if a tank sweep finds a tank?

Well if the tank was not previously disclosed it is news to both buyers and sellers.  And since no one knew about the tank, the tank needs to be removed and tested.

What about if a tank sweep finds a tank, can I test the tank?

Realistically, since you will not be using the tank, (ever) the smart move is to remove the tank and test soils where the tank was removed from.    Soil borings can cost almost as much as tank removal and you cannot test under the tank so you will not be $100%.  You can have contamination under the footprint of the tank which can require remediation.   To be fair if you have contamination under the tank depending on where the tank is located, you won't have a $40,000 cleanup, but you could spend $5000 to $10,000.  

What about if a tank sweep finds a tank, can you pivot and then tell me if the tank is leaking?

Tank sweeps use mobile radar units (see below photo on the left).  These units are carried in a SUV.  To perform soil borings you need a drilling unit which is carried on a trailer and towed by a pickup trucks (see photo on the right).    Both pieces of equipment are over $50K and are not brought to a tank sweep typically as you do not know if you will need to drill and if you read the above question you can see why removal is better.  In addition every state requires that you obtain a underground utility markout before you drill or dig, this can take 3 to 4 days and is not obtained for a typical tank sweep.    You also typically do not have permission from the property to drill on their property, tank sweeps are non invasive. 

Need to learn more about tank sweeps? Click here. 

Protecting your interest when you buy a property is called Due Diligence and one of the most important due diligence steps you can take is performing a tank sweep with GPR. 

Why perform a tank sweep?

Most homes built before 1980 likely had oil heat at one time, so 90% of single-family homes likely had oil heat in the past, possible several owners before.  Oil tank are made of metal, they rust, they leak and it can cost thousands if not tens of thousands of dollars to cleanup.  You don't want to buy a home that has an oil tank liability.

The home in this photo series is  circa 1920's, so oil usage was 100%. 

Buyers were told the basement had two ASTs (Aboveground Storage Tanks), that were removed. This photo shows where the ASTs were located in the basement.

But just because a property had an AST doesn't mean the site didn't have a UST (underground storage tank). 

So why bother to do a tank sweep for a property where there is documentation of former Aboveground Storage Tanks?  Simple nothing lasts forever and the older the property, the more likely that a tank may have had to be replaced.

Can you see evidence of a UST in this photo?   

It's obvious to the trained eye.

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All photos on this page are from the same property.     The buyers were told the home had oil heat, the oil tank was an Aboveground Tank in the basement, which was true but seller's failed to mention that the AST replaced an Underground Storage Tank (UST).  Or the owners didn't know that there was a UST since they didn't do a tank sweep when they bought the house.   Although the sellers had their own consultant use a metal detector to scan the site, which couldn't locate a UST.

Simple is not always best.  No doubt your current smart phone (phone, camera, computer, GPS, etc.) in your pocket is a vast improving from your phone of 10 years ago.  Most likely more expensive but it does so much more.

Having the best available technology also translate to an effective tank sweep.   A $225.00 tank sweep with an $800 metal detector, it not an effective tool for locating tanks, as the cost of the equipment can attest.

The sellers metal detector results?

The metal detector produced some deflection around the plant bed indicating a possible metal tank.    Curren scanned the area with GPR and fund the metal signature were the oil tank lines from the house to the tank. 

The metal detector then went over the adjacent driveway.  The findings?

The metal detector indicated a slight, faint response at a location about mid-way beneath the driveway directly in line with the remote fill. Due to the faint nature of the signal, possibly caused by wire or rebar in the concrete driveway pad, the location could not be defined.

When you need work performed you want to hire a professional with years of experience and the best possible tools for the job.  Curren was hired by the buyers to perform a GPR tank sweep.

Within the first 10 minutes of the Curren technician being on site, we were able to locate the remote oil tank fill which had been covered over with soil.   See photo below, the red tile probe is pointing to a round cap in the landscaping which is the tank fill.

If you were buying a commercial property, you would perform a tank sweep with GPR as that is the standard and most effective approach.  But if you are buying a commercial property, you are more experienced than the run of the mill buyer.

Curren scanned the driveway with GPR and located the tank, which the metal detector could not pin point.   Yes the owners recently redid the driveway and will have to dig up part of the new driveway to remove the tank.  Did the owners know the tank was present?

The tank is outlined in yellow lines in the photo below.  The tank was under reinforced (steel) concrete making the metal detector useless, but allowing the Ground Penetrating Radar to locate the tank.

The best service directly correlates to most experienced and using the best equipment.  Hiring chuck in a truck with an $800 metal detector, who also works out of their house, may offer an attractive price, but are you getting the best service?  Is the metal detector really the best device?

To be fair performing a Geophysical evaluation which is what a tank sweep is, can involve using multiple technologies.   When we find a buried anomaly (tank) we typically also verify the anomaly as metallic using two different metal detectors.  Trust me when you find a tank that a seller didn't know exists, they want to know it's a tank, confirming a metallic signature helps the medicine go down, it is just a metal detector should not be your only technology you rely upon.

The best tanks sweeps are performed by companies that also remove tanks.   There was no rhyme or reason as to where oil tanks were buried.  Removing tanks give you experience in how tanks are situated on a site.  Curren Environmental has been removing tanks for over 30 years and is licensed to remove tanks in 3 states.    We also have removed tens of thousands of tanks, so we know what we are looking for.

                    Why is an Oil Tank Sweep Important?

From 1900 to 1945 coal was king (coal shortages were common during WWI). By the mid 1930’s oil burners had made quality and safety improvements that made oil a competitor to coal. In 1940 more than half the homes burned coal. America oil reserves and steel making prowess from WWII allowed oil to be rapidly adopted after WWII (1945).

In the 1970’s and 80’s due to natural gas shortages and price irregularities the natural gas market become deregulated. Deregulated allowed for competition and market based pricing, which meant lower prices, this drove the popularity of natural gas. So natural gas didn’t become popular until the late 1980’s.

For homes built between 1900 and 1980, oil heat was highly probable at some point in the past (in short what were your alternate choices for heat besides oil?). Construction codes didn’t address oil tank removals until the 1990’s. Environmental regulations today have strict standards for heating oil leaks from tanks in soil and groundwater. In short, an oil tank leak can make the owner of a property a polluter so to speak. On top of that the regulations view the current owner of a property as the Responsible Party (RP) for the cleanup.

Today, you could buy a house built in 1950, that used oil until say 1980, when a conversion to gas occurred. The old oil tank was literally just left in place (abandoned), since doing anything cost money. Fast forward to 2020, you are buying that home with an oil tank that hasn’t been used in decades. If you don’t add a tank sweep with GPR (ground penetrating radar) to your home purchase due diligence you are opening your self up to a responsibility and an expense with the oil tank, as when you sell someone will do a tank sweep and find the tank you never knew you had or used, which happens all the time.

Today the internet is used not just for shopping, but for education. There are homeowners that have an oil tank on their property (used or out of service), these homeowners have learned via the internet (websites like this one) of the liability of an oil tank. We find that some people will hide the evidence of the tank and hope that no one looks for an oil tank, since the home is now heated by natural gas. Do you find it hard to believe that someone would try to hide the truth? Follow this story.

Home went under contract, home inspection and all, everything but a tank sweep with GPR was performed by the purchaser of the home. One day before settlement the prospective homeowner does a walk through of the property and low and behold someone spray painted "tank" on the ground. (this is a true story. I couldn’t make things like this up).

Home was a flip, so the owner (really owner for 7 months) had no knowledge of any oil tank. Curren scanned the marked area and bingo oil tank, about ¼ full of oil. We can only speculate as to why the tank was hidden and why someone spray painted tank on the sidewalk. The general theory is a neighbor was aware of a tank at that location and also aware the owner removed evidence of the tank. Presumable the neighbor removed their tank and didn’t appreciate the neighbor not doing the right thing and removing theirs. We believe this is a likely scenario as we have seen it on other sites that we have performed tank scans/sweeps. People will park cars in driveways over tanks. People will say a tank was removed and we scan the area and find a metal object indicative of a tank.

We even have people who have removed their own tanks, we get contracted to do soil borings and soil sampling from the removed tank area. $35,000.00 later, we find that the tank did leak, the owner just thought that oil is naturally present in a removed tank excavation.

Bottom line you cannot rely on statements from a seller such as these:

There is no oil tank.

That the tank was removed

The removed tank didn’t leak.

Do you need to complete a tank sweep? Yes, if the home was built before 1980 and you can’t get 100% written documentation that natural gas was always utilized to heat the dwelling.

Buying a home is one of the top ten most stressful situations in an adult’s life. The stress of the inspections, cost of inspections, time and effort put into buying the home is extensive. The amount of inspections one will go through to buy a property could be, at least, totaling six (6). One of those inspections should include searching for an underground oil tank.

Underground oil tanks have a finite life span and were not built to last forever. If you forego the tank scan, you may have just bought yourself an underground oil tank. If the tank leaks you could be faced with a large and pricey problem. Not all recent homeowners are even aware that they bought a home with an underground oil tank.

Top 8 Reasons for a Tank Scan:

1. House built before 1980.
2. Above Ground Oil Tank.
3. Fill Pipes.
4. Vent Pipes.
5. Copper lines are visible.
6. Neighborhood that typically has Underground Storage Tanks
7. Furnace Chimney.
8. Previous tank scan was done with a magnetometer.

House built before 1980
If the house was built before 1980 you should presume that there could be an underground oil tank unless the seller provides you information otherwise. But beware, if a tank scan was done with a magnetometer, the scan may not have been enough to identify an underground oil tank. Ground Penetrating Radar is the most advanced technology used in today’s market to identify buried tanks.

Owner has no knowledge of prior oil heat

Oil was king from 1900 to late 1980, tanks were installed after 1980 but they are not as common.

We tell people assume the property had oil heat, prove to me it did not.

Above Ground Oil Tank
Prior to oil used as the main heating source, coal was providing the heat in the home. Coal was difficult on the homeowner, as you would have to shovel coal every 4-8 hours to keep the heat on. After coal, oil tanks became a popular heating source. The tank was buried as it was not an added value in the property aesthetics. When homeowners believed that the underground oil tank was no longer working, or it was time for a new tank an aboveground oil tank was installed. In essence, if there is an aboveground oil tank than there is a possibility that an underground oil tank exists on the property.

Fill Pipe

Oil tanks have fill pipes where the oil is distributed to the vessel. The fill pipe is attached to the oil tank and is what the oil delivery company uses to fill the tank with oil. If the fill pipe is noticeable during the home inspection, then that is a sign of an underground oil tank.

Vent Pipe
The vent pipe on the oil tank allows air/fumes to escape from the tank when the fuel is being added. The vent pipe commonly has a mushroom like cap to keep water from entering the oil tank. If a vent pipe is visible than that is sign that there my have been an underground oil tank at the property. If only a vent pipe is found then that means the tank may have been abandoned in place, meaning filled with sand or another inert material.

Copper Lines
The oil fuel lines are made of copper tubing (lines) that allow the fuel to move from the tank to the furnace and back to the tank. The supply line provides the fuel from the tank to the furnace and the return line supplies the fuel that was not used back to the tank. If there is any evidence of current lines or lines that were cut, then there may have been an underground oil tank.

Neighborhood
Neighborhoods start with one home, moving to many, many more homes. Each neighborhood has a timeline, starting with the first home built. If this home was built prior to the 80’s than there is a possibility that a tank was on the property. The neighborhood may not have had a gas hook up line till after the homes were built, meaning there needed to be another source of heat prior to gas. If the neighborhood homes were built prior to gas in the neighborhood that it is likely that there is another source of heat and that could mean an underground oil tank.

A Furnace Chimney
In many old homes the chimney was not just used for wood burning, it was used for coal or oil. Check the chimney and see how many flues there are.

Previous tank scan with a Magnetometer.
There have been many instances where Curren Environmental is called upon to determine whether what the previous metal detector tank scan found is an underground oil tank. Metal detectors find any metal in the structure or asphalt/concrete. A/C units, reinforced concrete and chain link fences all have metal. There have been water lines and sewer lines that have been thought to be underground oil tanks, or on the flip side they were thought to be sewer or water lines and not an underground oil tank. To save money on inspections, start with the Ground Penetrating Radar not with a metal detector.

More questions?  Call our office today and speak to someone in person.

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Why performing a Tank Sweep?

There are many inspections performed when buying a home, and most are cursory visual inspections of the HVAC system, soffits, chimneys, foundation, plumbing, sidewalks, decks, swimming pools, etc.  These building components are commonly evaluated as part of your home inspection.  What is missed by many buyers is the environmental liability aspect of purchasing a home. Environmental can be asbestos, radon, mold, lead paint and oil tanks.  Of all these environmental liabilities, oil tanks represent the biggest risk relative to remedial cost.  A hidden underground oil tank can cost a couple thousands of dollars to a new homeowner if it's not caught during the inspection process.  Worse is when an oil tank leaks, which can lead to costs into the tens of thousands of dollars.

When people are on the fence about doing a tank sweep, all I tell them is not to be surprised that when they sell the home in the future and a tank sweep is performed by that buyer.

Over the past 20 years oil tank sweeps, oil tank scans and/or oil tank inspections have become a common part of the home buying process.

Why perform an oil tank sweep?

Oil tanks belong to a property and if you buy a home with an oil tank you bought all the costs associated with the tank, meaning tank removal, soil testing and most expensive remediation (if required). 

The photo below is a remediation of a leaking oil tank.

Oil heat was popular in the Northeastern United States from the 1930's to the mid 1980's, this time frame encompasses a large part of the homes in the Northeast, meaning chances are the home you are looking to purchase utilized oil heat in the past.  Also homes built before 1930, most likely had oil heat. since coal was phased out as soon  as a homeowner had a chance to switch, since coal required physical feeding the furnace several times a day during the heating season.

More info on Tank Sweeps

What percentage of tank sweeps find prior oil heat?

With over 20 years experience with oil tanks, we have crunched the numbers and find an average of about 75% of the tank sweeps find evidence of prior oil heat.  That number should not be that surprising since natural gas really only became popular in the 1970's.

Who pays for a tank sweep?

Buyers typically pay for the tank sweep as it is part of their due diligence.  Due diligence is what a reasonable person would do to investigate a property for problems prior to ownership.

Do property owners ever do tank sweeps?

Most property owners do not perform tank sweeps as they do not want to find an oil tank.

The photo below shows a tank found by Curren during a GPR scan.   Home built 1978, sold in 2016, with no  tank sweep.

Tank scan with Ground Penetrating Radar (GPR) or metal detector?

You should use both GPR and a metal detector to be thorough when performing a tank scan or tank sweep. Rely on GPR the most as it is what commercial sites use, metal detectors are more to prove that the object found by GPR is metallic.  Remember, the best equipment is the most expensive, an $800.00 metal detector on Amazon.com should not be relied upon.

Metal detectors beep if they find iron sand (a real thing), buried pipes, get too close to a metal fence or a structure with metal (yes homes have metal) or simply encounter buried metallic trash.   GPR uses a screen so the geophysical technician can see the graphical image detected by the GPR antenna.     Larger signals are tanks, smaller signals are usually pipes.

Do you need a Ground Penetrating Radar/ Tank Scan?  Call Curren Environmental Today.