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Why GPR Tank Sweeps are so important.

Sep 1, 2020 8:15:00 AM / by David C Sulock posted in OIl Tank Sweeps, tank scans, oil tank leak, foam filling oil tank, pa tank removal

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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 costs 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.

 

Houses with AST's may also have had UST's

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.

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.

Tank sweeps experts

 

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.

metal detectors are poor toold for finding tanks

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.

IMG_6083

Tank Sweep Questions?

IMG_6082-1

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 pinpoint.buried oil tank GPR image

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.

 

GPR Tank Sweep

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 its 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.

 

Ground Penetrating Radar tank sweeps

We also have removed thousands of tanks so we know what we are looking for.Tank sweep experts for over 20 years

 

tank experts

locating buried tanks

 

professional tank sweep

 

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Top 8 Reasons Why You Need a Tank Scan.

Nov 11, 2019 11:45:00 AM / by Tiffany Byrne posted in OIl Tank Sweeps, tank scans

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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.

IMG_4352

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 in Basement Leading to underground oil tank-1

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.

Call Curren Today

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Why performing a tank sweep is important when buying a home.

Feb 18, 2019 11:05:23 AM / by david sulock posted in tank leak, OIl Tank Sweeps, tank scans

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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.

 oil tank scan

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 tank leaking-5

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.

oil tank sweeps for home purchase

 

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.

 

Tank Sweep Questions?

 

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.

Tank sweeps with GPR

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

1-888-301-1050 

 

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