When you buy land on which you plan to build a house, you need to make sure that there are no underground impediments that might cause a sinkhole to develop. Sinkholes are craters which form in the ground, causing things on the surface, such as homes, people, and cars, to sink into them.

Sinkholes can be deadly . For example, in 1993 a 100 foot wide sinkhole formed under a hotel parking lot in Atlanta. Two people died and numerous cars were destroyed. That sinkhole was 25 feet deep.

Before you build, you should have a geologist ensure that your subsurface is in good shape. You do not want to build without ensuring that the surface will remain in tact, and will not collapse into a sinkhole. A geologist can perform ground penetrating tests to ensure that you will be ok.

Sinkholes can form for a variety of reasons. To some extent, the reason one might form depends on where the property is located.

For example, if you live in a mining community, you may suffer from a sinkhole caused by an abandoned underground mine. In Pennsylvania, where mining has occurred for hundreds of years, this is so common that the State has created a sinkhole insurance fund. The name of the State program is the Mine Subsidence Insurance Fund and it is administered by the State Department of Environmental Protection. The Fund has existed since 1961.

Each year sinkholes caused by old mines cause millions of dollars in damage. If you are purchasing property in a current or former mining area, at a minimum you want to check the subterranean integrity and consider purchasing this kind of insurance. Many homeowner policies will attempt to exclude these kinds of claims.

According to the Federal Emergency Management Agency, sinkholes can occur naturally as well. Underground water streams can erode a subsurface area, thereby resulting in a surface area collapse. Again, consult a qualified geologist before you purchase. You do not want to get stuck with unbuildable property.

Any underground void can cause a sinkhole. This can include underground storage tanks that were emptied and kept in place. Over the years, these tanks may collapse from surrounding pressure, causing a sinkhole to develop. A leaking water main can also result in a sinkhole.

In New Jersey, sinkholes have developed that have been caused by buried construction debris. Though not technically legal, some builders will bury small amounts of debris after they have completed their project. This burial can create a void, which in time can result in the formation of a sinkhole.

Several years ago, one such sinkhole engulfed a small New Jersey child in a new construction area, killing the child. Criminal charges and civil litigation followed.

The lesson to be learned is the same lesson that applies to any real estate purchase: caveat emptor or let the buyer beware. Buyers need to know about the property they are buying and building upon. This means they need to understand what is above ground, and what is below ground.

Structural engineers and geologists should be consulted when prudence so dictates. Or you can skip that step. Probably you will be fine. But if there is a problem, it can be very costly. The question you need to answer is whether you want to pay a little now, or do you want to potentially pay a lot of money later, if things go bad.

If you buy a new home with sinkholes, you may have rights against the seller. You need to find out how the sinkhole developed. Was the cause of the sinkhole something that the seller knew or should have or could have known?

Also, what promises did your seller make in the sales contract. Certain express or implied warranties may prove helpful. Also, in the case of new construction any warranty program may provide you with some relief.

A small sinkhole may evidence a problem that in time can worsen. So sinkholes should not be ignored. Consult a structural engineer at once and place any possible insurance carrier on notice as well. Since these are difficult, often dangerous and costly issues, legal counsel is often required so that your rights can be fully explored and protected.

The information provided in this column is written by Stuart Lieberman,a practicing environmental attorney, and is for general information purposes only. It is not legal advice and should not be used in place of legal advice.

Stuart Lieberman, Esq., and IRED.Com, Inc., will not accept any responsibilty for any reliance on the information in this column or any damages whatsoever resulting from reading this column.