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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 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 my filled in place tank has to be removed?

(aka Closed in place tank has to be removed to sell a property)

Every tank needs a report with testing to say the tank did not leak. Tanks abandoned in place avoid having testing performed which negates finding out if the tank did or did not leak.

Case in point, the above photo is a tank that was filled with foam.  You will notice that there are no access holes cut into the tank that would have allowed tank entry.  Yes you can see the large horizontal access hole Curren cut into the tank, but  no such hole was there before, which means the tank was never cleaned of residual oil.  See the oil in the tank and on the foam? You can see that to clean a tank you need elbow grease to go inside the tank, any oil left in a tank can leak in the future, hence why closed in place are removed.

Remember when people thought smoking was healthy?   There was a time when people and the tobacco industry didn’t openly speak of cigarettes as being unhealthy or addictive. This correlates to tanks that were previously filled in place without a “non-leaking certification”.   Few people want to find a problem, meaning their tank leaked, since problems have to be solved and that can cost money.   Oil tanks rust from the inside and out, and the cleanup of these leaks can cost thousands if not tens of thousands of dollars.

This tank was filled with sand, to absorb the oil in the tank, rain water filled the tank pushing the oil up and out into the soils.  $29,000 later the tank was removed and the soil remediated.

Many property owners either being naïve or savvy had their buried tanks filled in place years ago.  Believing or hoping that if they hired a company to fill their tank (not a DIY project) and getting a local permit in conjunction with township/municipal inspection the tank would never be an issue. Fast forward to today, same property is being sold and its owned by either the same people who filled the tank in place or a subsequent homeowner (who typically naively bought the property not understanding the tank liability) and now the buyer wants the tank removed and tested.

These are all reasons why today's buyers want oil tanks removed and tested, to prevent the tank from being an issue in the future.

Statements from property owners calling our office about their tank over the past 25 years.

1. I don’t want to remove the tank and find a problem, its legal to fill it in place, I want to do that.
2. Why do I want to test the tank and find a problem?
3. I want the tank filled in place, I don’t want testing.
4. My tank was filled in place but they put a camera into the tank before filling it in place.  (Absurd, but a few people a year say this)
5. My tank was filled in place and tested. (Unfortunately I can find the paperwork for filling the tank I just cant find the testing data.  (Because it was never tested)
6. My tank was tested before filling in place, but a different company did the testing and I can’t find the eating data.  (No one pays two companies to do something one company can do, unsurprisingly these people cant find anything regarding testing, contract, invoice cancelled check.  We call this unicorn paperwork, only the pure of heart can see it)
7. Removing the tank will disturb my prized lawn, bush, special tree, sprinkler line, flower bed, etc.   They never say it was a bad idea beautify the area above the oil tank.

A little history, in the 1990’s Federal regulations were established regarding commercial tanks (gas, diesel, kerosene, aviation fuel) and there were clauses where a commercial tank could not economically be removed that the tank could be filled in place, AFTER holes were created in the bottom of the tank allowing soil sampling for leaks to be obtained.  

These regulations created a tank removal/closure industry and established standards for tank removal and closure in place, these standards said evaluate for leaks, do testing, document (draft a report of the work), report leaks to appropriate government environmental agencies.   So companies doing  tank closure had a Standard Operating Procedure (SOP).

These photos show coupons (holes) cut into bottom of tank for soil sampling.

Now these testing regulations didn’t apply to residential oil tanks, but there was an awareness that if a leak was discovered it was reportable and cleanup maybe necessary.  So property owners circumvented the proper course of action and instead of removing a tank, and potentially finding holes in the tank or smelling oil impacted soil, they chose the route of tank abandonment in place. While I can comment on every company doing tank work, but I am sure many recommended sampling due to future real estate transactions, but in the end, the companies get paid for doing tank work with or without sampling so you have thousands of tanks that were filled in place without testing that now have to be dealt with in a real estate transactions.  

We can personally  attest that Curren has always suggested soil sampling for tank removal or closure in place, some people deferred this testing.  About 17 years ago we made it policy, Curren won’t work on your tank if you don’t complete sampling.   We took this stance so property owners didn’t get stuck in a future sale and so people didn’t stick another person with a leaking tank. Unfortunately this was not followed by other companies.

Some 40% of tanks we have removed were tanks previously filled in place, so believe me if you have a property with a tank that was filled in place without testing, you will get it removed if you want to sell the property. 

No you can't climb inside a tank when filling it in place and see pin holes.  Ever get a flat tire?   Did you see the hole?   See the photo below?  This tank was removed, do you see any holes in the tank?

Well there were a few holes that were apparent after the dirt was scrapped off the tank.  If this tank was filled in place and remained in the ground, there holes would not have been apparent if the tank was not removed.

Many people like to present the local permit obtained for abandoning the tank.    People somehow think the approval from the town means the tank didn't leak.  Please note that no your local permit which the town approved for filling the tank in place doesn’t certify the tank didn’t leak!  It certifies you filled a tank in place with or without testing (which while legal, makes it harder to sell, ahem near impossible to sell)  mortgage companies, insurance companies and attorneys for buyers will have a hand in preventing the sale with an inground tanks.  Too much liability, unknown cleanup expense is what causes the hesitation.  No one knows if the potential tank cleanup is $10,000.00 or $120,000.00?

If you own a house with an abandoned untested oil tank, expect to either have the tank removed, or the prior work to be reverse engineered, meaning all the material in the tank removed, holes cut in bottom of tank and soil ampler obtained, then the tank back filled again.  We just did this for a tank filled with foam under an addition, so yes it happens.   Buyers will want the know if the tank leaked, trust me if you were buying a property with an abandoned tank you would want to know the same thing. 

Have a tank question?  Call the experts

Expert mold advice, that is what you would want if you had a mold question - right?  Everybody wants the best available advice, but is it possible to get expert mold advice?   Finding a true mold professional is like finding a needle in a haystack.    It’s hard and rarely accomplished.  You can blame lack of government regulations as a source of the scarcity of mold professionals.  You see New Jersey, Pennsylvania and Delaware have zero mold regulations, so every "Chuck in a Truck" can say they know mold.

On a fairly consistent basis (almost daily to be fair) we get calls from people all over the country  that have questions about mold, or need us to interpret mold testing that a professional they hired cannot explain.   Fact, if you hire a professional, they should be able to provide professional advice in writing and be able to understand test results.   If your expert has a Gmail account, works out of their home or says they are licensed, I would say these are three common threads we find from people who have complaints with a mold company. 

No mold regulations, means no licensing, no required competency or required training and testing, so what is stopping someone from changing careers,  say from selling cell phones to doing mold consulting.   True story I met someone with just that background at an event down the shore, suffice to say what they knew about mold was very little.  Or should I say, what they knew about mold was mostly inaccurate. Did you know the salt air and the pressure treated wood that are prevalent in coastal areas inhibits mold growth?  Well, either did he and he told me not to tell people that its bad for business, he said fear of mold sells.   Sorry, I can't make this stuff up.   

As an environmental consultant that consults on mold, you need to inform clients and provide recommendations on risk and courses of action.   You do not sell fear.   Mold is harmful to human health, that is established, I have had people not be able to inhabit a home, or office where mold growth was present.  I also have people who live in an environment where mold is present and levels in the air are in concentrations where I know health issues were triggered in other people, although the current occupants had no apparent ill health effects from the mold.   This is actually not uncommon as we all have our sensitivities to gluten, lactose and mold, so what might be harmful to one person may not be to another.  That is not to say mold is a selling feature of a property, it certainly is not but mold has to be looked at objectively.   

How to pick a mold company?

1. Look for a company that at least 10 years of experience, 20 is better.
2. Google their address, make sure they work out of an office, not a home.
3. Check the ago of their web site address:  https://www.iplocation.net/domain-age     The longer a domain has been in operation, means the longer the company has been operating.   
4. Ensure everything provided to you is in writing, meaning scope of work, what they will do, how they will test and what the test results will mean.  Look we all know an A grade is better than a C, and an F is the worst, well translate that into mold test results. 

At Curren Environmental we have built a base of knowledge on mold consulting and mold remediation over a 20 year period.   We meet all criteria listed above.

Buried oil tanks rust (rust never sleeps) so oil tanks can leak.  

Do not be naïve that the tank that you are removing is rust free and has zero chance of leaking.  Anyone you hire to remove a tank should discuss the possibility of the tank leaking and what the steps would be to address a tank leak. In short, it should not be surprised that a buried metal object decades old may have leaked, so you should be aware of your options.  

In Pennsylvania what drives the need to remediate a heating oil tank discharge is if petroleum levels in the tank excavation are above the PADEP Statewide Health Standards relative to number two heating oil in soil.     The standards are as follows:

• Benzene:– (PADEP Standard is 0.5 ppm)
• Ethylbenzene: (PADEP Standard is 70 ppm)
• Isopropylbenzene (Cumene) : (PADEP Standard is 600 ppm)
• MTBE: (PADEP Standard is 2 ppm)
• Naphthalene: (PADEP Standard is 25 ppm)
• Toluene: (PADEP Standard is 100 ppm)
• 1,2,4- Trimethylbenzene: (PADEP Standard is 8.4 ppm)
• 1,3,5- Trimethylbenzene: (PADEP Standard is 74 ppm)

*Exceedance of any of the eight compounds indicates petroleum levels are above PADEP residential soil standards.  Please note that the most representative soil sample is one obtained below the tank which is only possible when the tank is being removed, or if the tank is being closed in place coupons or holes can be cut into the tank to obtain samples.. 

On the day of tank removal no one can tell you with 100% certainty that if they see holes in the tank that you need remediation.  You see without lab testing you don't know 100%.  If you are pushed to remediate right after a tank is removed, DON'T.   There are no savings and you risk spending money you may not have to spend.   We see firs recommending you jump into remediation if your tan leaks because they already have equipment on site, this approach is sure to lower your bank account balance with no guarantee of solving any problem.

So to understand oil in soil from a tank leak, you can compare it to cholesterol levels.   There are low levels of cholesterol (healthy levels,  that require you to take medicine or change your diet or life style) and there are high levels of cholesterol (you need to change your diet, possibly take medicine), in short high levels require corrective (remedial) action.  

You have to base any driver (need) to remediate a tank leak on laboratory analysis, which is obtained from sampling the soil after tank removal and which takes about a week to be analyzed by an independent laboratory.   So you sit in limbo for about a week to know where you stand.  Very similar to a Dr. visit with lab work.

Fact, many tanks, do not leak, many do, but not evert tank that leaks needs remediation.

Curren has over 2 decades of environmental experience, thousands upon thousands of sites worked on.  If you want professional advice from the professionals, call Curren.

Utilizing foam to fill an Underground Storage Tank (UST) can be a cost-effective approach to closing a UST.   Injecting foam into a tank can save the cost of excavating the entire tank.  Larger tanks and tanks that have access issues & hard surface coverings such as asphalt, building, paving or structures tend to be the ideal sites for foam filling.

Is foam filling appropriate and cost-effective for every tank?

The short answer is it’s not cost-effective in every situation.  People think you can just stick a hose into the tank and pump foam, but that's not the case. The tank must be exposed, entered, and cleaned of all oil before foam can be injected. Also, residual oil in the tank breaks down the foam, so the tank must be thoroughly cleaned of oil or else you will have an issue making proper foam.  In short, you have to enter and clean the tank, and for small tanks, it might take that much more effort to remove the tank, since you already excavated part of the tank to enter and clean it.

No matter if you foam fill a tank, fill a tank with sand/slurry, or remove the tank, there is still a set of tasks and associated costs that will be incurred, no matter the approach.

First, permits are required so the work can be inspected by the local municipality.

Second, the tank has to be excavated to some extent so the tank can be opened, entered, and cleaned. You see, you have to clean the tank of all liquid prior to filling it or removing it. Cleaning entails going inside the tank. Now depending on the size of the tank, the physical act of exposing the top of the tank may entail exposing 60% to 80% of the tank, which at this point, it may just be another 10 to 15 minutes to uncover the rest of the tank, making removal not that much effort.

Third, once the tank is cleaned, you need to test the soil, which entails cutting holes in the bottom of the tank. This takes longer than someone would expect, as the person who cleaned the tank has to leave the tank, change work clothing, to cut these holes. Whereas in the situation when you remove the tank, it is much easier to sample the excavation as the soil is exposed.

Finally, you have the task of backing the area. If you remove the tank, backfilling is fairly straightforward, as you have an open area to fill in.

If you are leaving the tank in place, you are tasked with placing material in the access hole you cut in the tank and pushing it to the far end of the tank. Remember the tank is a cylinder, and you need to fill the cylinder, and sand is not self-leveling.

Utilizing foam is convenient as it is self-leveling, but you also have to make the foam on-site.

The prep for making foam can be 1.5 to 2 hours. It’s kind of like baking, you need the ingredients, a proper mixture, and a temperature. You also have about 2 hours to clean the foam trailer post filling, as the equipment and lines have to be devoid of the foam ingredients or else they will harden and clog hoses, fitting valves, etc., so you are cleaning the kitchen, so to speak. Foam filling hits a sweet spot when you have hard issues accessing the tank with other materials, such as sand or concrete. Also, larger tanks (tanks greater than 2000 gallons) are more cost-effective to foam fill, as you realize the advantages of the foam cost structure versus the labor of using sand or slurry.

Propane tanks are uniquely suited for foam filling as they are pressure vessels and longer than the same size oil tank.  Longer tanks disturb a larger footprint to remove, so foam filling is an ideal solution for propane tanks.

Green Lawn Tips

During this trying time, you may be at your home more than you have been in the past.  As we try to find things to do where we are not around many people, it may be a good time to fine tune your lawn.

Americans spend over $6.4 Billion a year on lawn care, according to the Professional Lawn Care Association of America. While we are at home now, it may be a good time  now to ensure a beautiful green and healthy lawn.

Start out by checking the soil pH levels. Winter can alter the soil pH and create conditions that are friendly to weeds and disease. The soils pH should read between 6.5 and 7.0 which are slightly acidic. You can test your soils pH by purchasing a pH tester.    Lime can be added to adjust pH.

After the soil has been checked, invest in a rental aerator (you can group rent with a neighbor). In high traffic grass areas becomes compacted. The aerator will draw wine cork-sized plugs out of the lawn surface giving roots the room to spread and allow for air, nutrients and moisture to penetrate the soil.  Leave the cores where they lie a they will ad nutrients to the soil.

Pro Tip

The soil cores should not be raked, as they contain bacteria and nutrients that will return to the soil.

In the early spring, apply a pre-emergent weed control to prevent crabgrass in early spring. https://amzn.to/3b6dzXz (Right now would be a good time)

Pro Tip

½ the dosage of preemergent (now) and reapply in 3 weeks to increase the treatment duration. Try to get your immediate neighbors to do the same so you encompass a larger spread of weed control. If your neighbor does not apply preemergent, weeds can grow and move to your yard.

During late spring fix any patchy places and apply your seed. When seeding in the spring it is pertinent that you provide consistent watering to allow the seed to germinate

Pro Tip

When you plant seed, the seeds must reman wet to germinate. Water twice a day for 7 to 10 days to allow the seed to germinate.

When watering, make sure one inch of water to 12 inches of soil is preferred ratio for watering actively growing grass. You most likely will have to seed again in the fall months.

Pro Tip on conserving water

Twice a year in season (Spring and again in July) apply a wetting agent, this makes water wetter.  Wetting agents apply a non ionic surfactant (soap) which allows water to more evenly penetrate soil (think less run off).  Golf course follow this process. Lawn Wetting Agent

With the spring upon us, it is very important to prepare your lawn for the warmer, sunnier months ahead. Having a nice, thick green lawn helps with excess rain, capturing the moisture so it does not end up in your house to produce mold.

Questions about Mold growth?

Crazy times, first full day of Spring and we all want to be sprung, but realty is more likely we will be staying at our homes for awhile.

If you like to be in your yard AND you have had issues with mosquitoes in the past, maybe this is the year to seek professional help by having mosquito control & remediation performed in your yard. Our service will remediate (remove) mosquitoes from your yard.

Book a seasonal service, 8 applications and get $25.00 off. We start treating mid to late April.

Why start controlling mosquitoes in early Spring?

You start early whack the buggers, then you keep them suppressed for the rest of the season with reapplications every 3 weeks. It more effective the earlier you start because:

1. We treat foliage as mosquitoes need the nectar from the leaves for food (blood is just for laying eggs and only the female bites).

2. With minimal foliage in the Spring, statistically speaking the mosquitoes are likely to encounter our barrier spray SOONER rather than later.

3. Treat early BEFORE you have a problem. An ounce of Prevention is worth a POUND of cure.

Call Tiffany at 

Many planned developments used heating oil.  In developments where the condominiums are housing, the homeowner does not own the land where the oil tank is located. In condominium housing developments most heating oil tanks are usually placed on common ground.    So you have a situation where you must remove the tank from property. The condominium owner does not own the heating oil tank. Homeowner associations, as anyone who has dealt with one, have many restrictions on what you can and can't do, they also make you jump through hoops to remove oil tanks.  These restrictions, while meant to maintain order and assure that work is performed professionally, also add to the oil tank removal cost.  We call these project "White Glove Tank Removals", as they require the white glove treatment.

Curren recently completed a project and  from the photos below, it is hard to differentiate the before and after photos. Hence the white glove treatment. 

The tank is in the planting bed between the dwelling and the sidewalk.  Planning ahead, allowed the parking spots in front of the tank to be clear to allow access.

The blue line is an old landscape sprinkler line.

Next you hand excavate to clear PRIVATE utilities.  Most all homeowner's associations have no clear idea regarding what utilities are where, so you hand dig to clear the excavation.

You dig until the top of the tank is exposed.

This tank was previously filled in place with sand. 

To remove the previously installed sand, you have to cut the top of the tank off so the soil can be scooped out.

Soils were removed and placed into a dump truck that removed the soils from the site.  This tank was in New Jersey and New Jersey doesn't allow you to back fill with soils removed from an oil tank.

This is the after removal photo.

Tank removed and back filled, almost like we were never there.

Over 20 years of experience and thousands and thousands of tanks removed, when you engage Curren Environmental you get our experience and expertise.  This may be your first and only tank removal, for us it's just what we do.  If you want your project completed professionally, call Curren.

"Why do I have mold?", is a common question we get from people who discover mold in their homes.   The short answer is that 95% of the time it is a moisture or a water problem.   Yes, mold can come back after remediation if you do not fix what caused the mold.  It can also come back if the mold was not properly remediated (wiping with bleach is not mold remediation).

Thousands of mold inspections and remediations have allowed a broad evaluation of mold growth patterns.  You can't be a good mold inspector if you are not accomplished in mold remediation.  Getting down and dirty remediating mold allows you to witness first hand how mold growth has occurred.  Remediating often times requires you to open up walls to get at the mold growth and you obtain a perspective as to how/why mold grows. 

For instance, wood studs allow mold to grow more aggressively than metal studs when you have a wet area.   Floating concrete slabs can enhance mold growth on ceilings. When there are areas of termite damage you should expect to find mold growth as termites like a moist environment, like mold.   Did you know that your beloved mulch beds around your home can aid in humidity in a basement and crawlspace? Thus, creating an ideal environment for mold growth.  Also, the dehumidifier bucket that you got sick of emptying (filled with water every 2 days) now sits unplugged in the basement, ruining your line of defense in controlling moisture and keeping mold at bay. These factors as well as a host of other environmental and degrading building in fracture are the common culprits that cause mold to grow in a home.

(For example, lack of drainage and added mulch beds led to mold growth)

Curren Environmental does mold remediation to homes that have had mold remediation previously and the mold grew back, meaning remediation was not successful.  This happens due to top lack of following proper mold remediation protocols, using inferiors products to prevent mold growth from reoccurring and lastly removing the moisture source (many times there are more than one source) identification.  (Curren had one project where there for four sources of moisture that fueled the mold growth.)

Mold growth is typically found in homes when the property is being sold.  It may not be bothering the seller, but it may affect the buyer.  Everyone has different intolerance and tolerances to mold growth, one of the reasons there are no federal regulations governing mold growth. Mold growth can be a huge real estate deal breaker. If it wasn't it would be on the sale sheet, showing the moisture or water issue and where the area of mold growth. 

No, mold growth will not be on the sale sheet.  It is best to remediate the mold growth before the property is on the market, removing the issue in its entirety. 

Questions on mold remediation? Follow this link or call Curren Environmental today. 

You recently had your oil tank removed and there were holes in the tank. However, there are no indications of soil contamination but the company that removed the oil tank filed a report to the New Jersey Department of Environmental Protection (NJDEP). You are unaware that you may have been naïve in choosing your oil tank removal company due to the fact that removing an oil tank hopefully would be a once in a lifetime event. At this point, you understand that clearly your tank removal contract should have included soil sampling, but it did not. You are also unaware that soil sampling must be completed, then the report is sent to NJDEP to close out the case number (assuming that it meets the state parameters for acceptable oil levels) and rescind the remedial action. 

Regarding what soil sampling is and how it is performed, there are permissible levels of oil that can remain in the ground and conversely there are levels that would require remediation. New Jersey regulations require that upon removal of an oil tank that has evidence of a leak, you are to obtain a minimum of 5 soil samples from the tank excavation (5 for a 500 gallon tank and 6 for a 1000 gallon tank). This is relative to your contract for tank removal. If the contract did not reference soil sampling, you can’t guarantee soil samples would be obtained. Soil samples are critical to assess the tank excavation for petroleum levels. The testing is meant to inform the property owner if indeed oil levels are present and remediation is warranted or that levels are within permissible limits and can be left in place. Now, you, as the owner of the oil tank that leaks can make an informed decision regarding remediation. 

If your tank removal contract does not include costs for soil sampling or discusses the possibility of finding a tank leak, it is pretty safe to assume that the tank removal company is looking to find a leaking tank and remediation.

In a situation where a tank is removed, found to be leaking and no soil sampling was performed, you should be concerned as to whether the soil needs remediation. All discharges are required to be reported to the NJDEP (If your tank contract doesn’t inform you that a tank leak is reportable, think again about who you are hiring).

Example of soil testing by soil borings. 

The only way you would know if your tank leak has petroleum contamination in the soil above or below NJDEP permissible limits is to have soil sampling performed. If all your samples are in compliance with NJDEP regulations you will receive a No Further Action (NFA) letter that will close out the NJDEP case number. This can be performed without having to perform actual remediation, which is typically soil removal.

Again, the tank removal contract should have addressed obtaining soil samples and what to do if a leak was noted. Remember, holes are never good in an oil tank and you rarely will see physical evidence of an oil discharge in a tank excavation, meaning you are not going to see oil or stained soils.

Expert advice with over two decades of tank removal experience. Curren Environmental, Inc.