State of New Jersey

Christine Todd Whitman

Governor

New Jersey Department of Environmental Protection

Robert C. Shinn, Jr.

Commissioner

August 1996

Federal and state laws require underground storage tanks (USTs) to have leak detection.

Leak detection violations can keep you from getting legally required insurance coverage and reimbursement for cleanup Costs. Without leak detection, you constantly risk discovering a leak only after it becomes a major financial burden and an environmental problem. In addition, if your USTs do not have leak detection, you will not be in compliance with federal and state laws and may be subject to penalties.

Inspections conducted nationwide indicate that most people who think they are doing inventory control are not doing it in a way that is likely to find leaks and meet the law's requirements for leak detection. So even if you are SURE you are doing inventory control right, read this booklet carefully–it could save you a lot of time and money.

If you need information on federal and state leak detection requirements and the various methods of leak detection available to you, see "Straight Talk On Tanks." Call DEP at 609/292-8761 and order this free publication by name.

The instructions in this booklet are keyed to two forms: the "Daily Inventory Worksheet" and the "Monthly Inventory Record." You will find filled-in sample copies of these forms on the last two pages of this booklet. These samples are on perforated pages, so tear them out and refer to them while you read through the directions that are keyed alphabetically to the sample forms. Also, near the back of the booklet, you will find "masters" you can copy repeatedly to provide forms for use in your recordkeeping. If these forms are filled out according to the instructions in this booklet, you will be in compliance with federal and state regulations for inventory control. You can use other standard recordkeeping forms, as long as they are clear, consistent, and contain all the information required by the federal and state leak detection regulations.

 

 

 

 

 

 

 

 

A tank chart is a table that converts the number of inches of liquid in the tank into the number of gallons. You need a tank chart that exactly matches your storage tank (tank manufacturers usually provide charts for their tanks). If you have more than one tank, you will need a chart for each tank unless the tanks are identical. The tank chart must show conversion to gallons for each _ inch stick reading. If your tank chart does not convert each _ inch reading into gallons, contact the tank manufacturer, or, if you have a steel tank, the Steel Tank Association (708 438-8265), to get an appropriate chart.

You always need to convert inches into gallons in order to fill out the forms correctly and to do the necessary math. To convert inches into gallons, find your stick's reading to the nearest _ inch on the tank chart, then simply read across to the gallons column to find the number of gallons. If you cannot get a tank chart showing conversion to gallons for each _ inch reading, you must do the additional math explained on page 9.

The fill pipe through which the fuel is delivered into the tank must have a drop tube extending to within 1 foot of the bottom of the tank. Stick measurements should be made through a drop tube in the fill pipe or gauging port. If your fill pipe does not have a drop tube, call your petroleum equipment supplier to have one installed.

Meters must be calibrated according to local standards.

If you have manifolded tanks or dispensers that blend fuel, consider these tanks as one tank system if they share a common inventory of stored fuel. As you follow the directions on the following pages, you will need to combine your measurements and calculations for all the tanks manifolded into one system.

You must measure the tank every day that fuel is added or removed. You may take measurements using a gauge stick or a mechanical or electronic tank level monitor.

Every day you measure the tank, you should fill out a "daily inventory worksheet." As you go through the following directions, refer to the sample daily inventory worksheet you will find toward the end of this booklet. For easy reference, the sample is on a perforated page so you can tear it out and keep it handy as you read through the directions. Also, near the back of the booklet is a "master copy" on a perforated page you can tear out to make copies of the daily inventory worksheet for your recordkeeping.

10 Fill in the identifying information at the top of the worksheet.

11 Next to the "Tank Identification" box are empty vertical columns. Each column represents one tank—consistently enter all information on that one tank in the same vertical column. NOTE: Once you have filled in the tank identification boxes, make copies of the worksheet so you won't have to repeatedly enter the same information.

USE GOOD STICKING PRACTICES: Slowly lower the gauge stick to the tank's bottom. Let the stick gently touch the bottom, then quickly bring it back up. Read the depth of fuel indicated by the wet mark to the closest _ inch division on the stick. Use of fuel-finding paste will make your stick readings more accurate.

NOTE: If your tank is equipped with an automatic tank gauge (ATG), you may record the inches of product and gallons of product directly from the ATG's printed tape or simply staple the tape with this information to the worksheet.

At the same time you measure the tank contents (Step 1), you must record on the daily inventory worksheet the amount of fuel pumped. No fuel can be added or removed from the tank while you are sticking the tank and recording the amount pumped.

16Add up the totalizer meter readings in each column and write the result in the box labeled "Today's Sum of Totalizers."

17Find the last daily inventory worksheet you completed. Copy "Today's Sum of Totalizers" from that worksheet into the "Previous Day's Sum of Totalizers" box of the worksheet you are working on today.

18On today's worksheet, subtract "Previous Day's Sum of Totalizers" from "Today's Sum of Totalizers" and write the result in the box labeled "Amount Pumped Today."

19If you are using cash register reports to record the amount pumped, enter the amount of each type of fuel pumped in the box labeled "Amount Pumped Today" or staple the printout to the worksheet.

You must check how much fuel has been delivered every time any amount of fuel is delivered to your tank. NOTE: You should not pump any fuel during the time it takes to do items "I" and "J" below.

Before the delivery begins, the liquid level in the tank must be measured. Always use good sticking practices: slowly lower the gauge stick, gently touch the stick to the bottom of the tank, then quickly bring the stick back up. Read the depth of fuel indicated by the wet mark to the nearest _ inch division on the stick.

The delivery person can now deliver fuel into the tank. After the delivery, wait at least 5 minutes for the fuel level in the tank to stabilize, and then measure again as described above.

Now look at the delivery receipt and find the volume of each type of product that was delivered. If two volumes are given, one labeled "net" and the other "gross," use the gross gallons as the volume of product delivered.

If your tank chart does not list direct conversions from inches to gallons for every _ inch, then you must do the additional math described below every time you stick your tank.

The easiest way to explain this procedure is with an example. Let's say you have a stick reading of 43_ inches and you need to figure how many gallons are in your tank.

1.Look on your tank chart and find the inch measurements that are just above and below your stick reading and write down the number of gallons for these inch readings. Subtract the gallon readings to find the difference between the two readings:

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2.Dividing 105 by 8 will give you the number of gallons per _ inch, which in this example is 13. (More exactly it is 13.125, but do round off the number to the nearest whole number.) Because your fraction is _, multiply 13 gallons by 3, which gives you 39 gallons as the volume represented by _ inch.

3.Take the number of gallons you have just calculated and add it to the inch reading just below your actual stick reading:

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Thus, your stick reading of 43_ inches converts to 3,519 gallons.

NOTE: If your tank chart is in half or quarter inches, you must still use this procedure so that your gallon readings are accurate to _ inch.

In this step, you will copy information from the daily inventory worksheet onto the monthly inventory record. You will then do some math to determine your daily inventory. You need one monthly inventory record for each tank that you have.

As you go through the following directions, refer to the sample monthly inventory record you will find on the reverse side of the daily inventory worksheet sample you have already been using. For easy reference, the sample is on a perforated page so you can tear it out and keep it handy as you read through the directions. Also, near the back of the booklet is a "master copy" on a perforated page you can tear out to make copies of the monthly inventory record for your recordkeeping.

If this is the very first day of your inventory recordkeeping, convert the "End Stick Inches" from the daily worksheet into gallons and enter on the monthly record under "End Stick Inventory (Gallons)" for that starting date. (If necessary, see page 9 on converting inches into gallons.) This is all you can do today. Starting tomorrow, follow all of the instructions listed below.

31 Add the "Start Stick Inventory (Gallons)" and the "Gallons Delivered" columns; then subtract the "Gallons Pumped" column. Enter the result in the column labeled "Book Inventory (Gallons)."

32 Copy the "End Stick Inches" number from the daily worksheet into the column labeled "End Stick Inventory (Inches)" on the monthly record. Convert inches into gallons and enter the result in the column on the monthly record labeled "End Stick Inventory (Gallons)." (If necessary, see page 9 on converting inches into gallons.)

33 Subtract the "Book Inventory (Gallons)" from the "End Stick Inventory (Gallons)." Enter the difference into today's "Daily Over or Short" box. This number will usually be a positive or negative number (only rarely will it be zero).

34 Enter your initials to show who entered today's information.

At least once each month, you must also measure for water in the tank. Smear water-finding paste on the bottom few inches of the gauge stick. Open the fill pipe and slowly lower the stick to the tank's bottom. Hold the stick on the bottom for 10 seconds for gasoline (30 seconds for diesel). Then remove the stick. If there is water in the bottom of the tank, the water-finding paste will change color. Read the depth of water indicated by the line where the water-finding paste has changed color to the closest _ inch division on the stick. Do not use this stick reading to measure the amount of fuel in the tank, because the fuel will creep up the stick and will give you an inaccurate reading.

36 If you checked the tank for water today, enter the number of inches of water in the tank on the line under "Facility Name" at the top of the monthly record. If there is no water present, enter a zero to indicate that you in fact checked for water but found none. If you find more than 1 inch of water, you should arrange for its immediate removal, notify the product supplier, and conduct further tests to ensure that the tank is not leaking.

At the end of each month, follow the directions below to see if the difference between "stick" and "book" inventory indicates a possible leak.

FACILITY NAME: _________________________________________

YOUR NAME: _________________________________________

DATE: _________________________________________

Is "TOTAL GALLONS OVER OR SHORT" LARGER than "LEAK CHECK" result? YES NO (circle one)

If answer is "YES", investigate for a suspected release (see page 12).