Leaking Underground Storage Tanks
FEATURES
HAZARDOUS MATERIALS
The Problems of and Precautions to Take with L.U.S.T.
Your alarm office receives a report of a gasoline odor in a detached, single-family residence on one of your quieter streets.
As you enter the basement, the smell of gasoline is enough to knock you over. You order an immediate evacuation of the house and direct your firefighters to ventilate.
The only gasoline in the home, a one-gallon safety can, is accounted for. There is no service station anywhere nearby and no sign of a parked delivery vehicle. You have absolutely no idea where the smell is coming from. It’s a puzzling dilemma and you feel stymied. Take heart, for you are not alone.
You are probably faced with L.U.S.T. Not the type of which cheap pocket novels are made, but rather leaking underground storage tanks, a growing national problem.
All across America, these metal storage containers, which have done their jobs so quietly and efficiently over the years, are starting to make their presence known in growing numbers. The problem lies in the deterioration of the steel that makes up the bulk of these tanks that were sunk or mounded over many years ago.
It is believed that the majority of underground storage tanks presently in use are constructed of steel, and only a very small number of these are protected against the corrosive effects of the earth. Given the fact that most of these tanks store gasoline or other petroleum distillates, the potential for property and environmental damage is great.
When you consider how many tanks have been placed into service under our towns and cities, you can begin to imagine the magnitude of the problem—one that we are only just beginning to come to grips with.
Recent estimates are that between 10% and 15% of all underground tanks are leaking. So, the odds of such an event occurring in your response district are pretty good.
Just how does the petroleum product make the move from tank to basement? The physical behavior of petroleum is the same whether it spills suddenly or leaks slowly. Petroleum finds its way into the soil and is moved along by gravity, hindered only by the type and permeability of the soil. It is absorbed more quickly by sandy soil and passes more easily through solid clay. When flowing through artificial fills such as pipeline trenches and utility conduits, its travel is accelerated. In come cases, the petroleum passes downward to contaminate the water table, while in others our first contact occurs when it surfaces in someone’s basement.
When faced with L.U.S.T., your primary consideration must be the safety of any occupants in the involved structure. Evacuation should be instantaneous and ventilation equally rapid, particularly in low-lying areas where vapors are more easily trapped. As the vapors move through your community, the potential exists for them to spring up anywhere that geological conditions permit. And those conditions may cause it to gather in the basement of residences, commercial buildings, schools, hospitals, etc., all of which have numerous sources of ignition. A hot water heater, oil burner, or defective electrical panel box might provide the spark to set off this disaster waiting to happen. You must take great pains to insure that you do not cause the explosion yourself.
There are some general safety precautions and operational procedures that you might want to make a part of your department’s standard operating procedures:
- Make a quick and reasonable effort to determine the degree and extent of the problem. Is the odor faint or strong? Can it be identified? Is the intensity of the odor or quantity of the liquid increasing or decreasing?
- Keep anyone not directly involved with your operation at a safe distance.
- Do not attempt entry until the vapor concentration has been checked with a combustible gas indicator. If your department doesn’t have one, be sure to know who in your community does have the capability to determine combustible limits. Such help is usually available from utility and water companies. To enter an area in which there is an undetermined concentration of some unknown vapor is
- to risk the possibility of fire or explosion.
- If toxic vapors or insufficient oxygen are suspected, these conditions should be tested via instruments.
- Isolate the danger area and notify those responsible for the building or area in question.
- Eliminate sources of ignition; however, the following cautions are important to remember:
- Electrical switches in the exposed area should be left untouched to avoid arcing.
- Extension cords should not be plugged in. If they are already plugged in, they should not be unplugged.
- You should try to shut off the power via controls located at a safe distance from the exposed site.
- Cut off the gas service from the outside in order to extinguish pilot lights and burners.
- The fans and pumps used to move vapors and liquids should be explosion-proof.
- Prohibit all smoking in the area. As simple as this might seem, it only takes one fool to blow you sky-high.
- Use natural ventilation to the greatest extent possible.
Fortunately, forces are already at work to ease the burden of worrying about L.U.S.T. At the national level, Senator David Durenberger (R-MN) and Congressman Don Ritter (R-PA) are preparing a bill requiring mandatory inventory, registration, and inspection of all underground tanks.
A number of states and local governments are acting independently of the federal government to attack this problem more quickly and efficiently. For example, New Jersey is moving to require that all underground storage tanks in excess of 1,100 gallons liquid capacity undergo periodic testing. The Monmouth County, NJ, Board of Health is considering regulations to mandate the installation of monitoring wells in the vicinity of underground tanks that would notify the owner of any leaks which might be moving away from their tank area. Contact your local health authorities to see what is being considered in the way of regulations for your community.
Though steps are being taken to correct the problem in future installations and minimize the problems in existing storage units, it is still up to you to pre-plan your community, both in terms of the potential for an incident of this nature and the equipment available to handle it. You’ll then be ready for that fox and hound situation where you must determine the cause for that unexplained aroma of gasoline in the basement of a citizen’s home in your community.
