Office of
Toxic Substances
Washington, DC 20460
October 1984
&EPA More About Leaking
Underground Storage Tanks:
A Background Booklet for the
Chemical Advisory
-------
MORE ABOUT LEAKING UNDERGROUND STORAGE TANKS;
A Background Booklet for the Chemical Advisory
Prepared by:
Exposure Evaluation Division
Office of Toxic Substances
U.S. Environmental Protection Agency
October 1984
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DISCLAIMER
The mention of specific trade names in this booklet is for
informational purposes only. EPA does not endorse any particular
product or system.
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TABLE OF CONTENTS
CHAPTER PAGE
Introduction 6
Leak Identification Methods 8
CHECK the Inventory 9
Simple Inventory Review 9
Inventory Review for Tanks with Metered 10
Dispensing Pumps
Inventory Review for Tanks Without 20
Metered Dispensing Pumps
Automatic Inventory Systems 24
Computerized Inventory Review Methods 25
WATCH for Environmental and Mechanical Signs 25
Environmental Signs 25
Mechanical Signs 26
Manway Inspections 28
TEST the Tank and Piping 28
External Tests 30
In-Tank Tests 32
A Few Words About the Safety of 33
In-Tank Test Methods
Underground Tank and Pipe Replacement and Repair 35
Corrosion 35
Steel Tanks 36
Fiberglass Tanks 38
Double-Walled Tanks 39
Piping 39
Cost and Warranty Information 40
Financing for Repair and Replacement 42
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Federal', State and Local Regulations 43
Federal Regulations 43
State and Local Regulations 44
Insurance 48
Helpful References 50
Appendix A; Blank forms to be used for tanks
with metered dispensing pumps
Inventory Review Sheet
Manifolded Tank System Recording Sheet
Dispensing Meter Recording Sheet
Appendix B; Blank form to be used for tanks
without metered dispensing pumps
Inventory Review Chart for Tanks without
Metered Dispensing Pumps
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LIST OF FIGURES
FIGURE PAGE
Figure 1. Tank-to-meter-to dispenser hookups. 12
Figure 2. Tank hookups and the appropriate 13
inventory review forms.
Figure 3. Sample inventory review sheet for 16
tanks with metered dispensing pumps.
Figure 4. Sample manifolded tank system 17
recording sheet.
Figure 5. Sample dispensing meter recording sheet. 18
Figure 6. Action numbers for tanks with metered 19
dispensing pumps.
Figure 7. Sample inventory review chart for tanks 22
without metered dispensing pumps.
Figure 8. Action numbers for tanks without 23
metered dispensing pumps.
Figure 9. Underground storage tank costs. 41
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INTRODUCTION
Leaking underground storage tanks can be dangerous and
costly. Leaks can mean loss of motor fuel and they can mean
contamination of community drinking water supplies. The U. S.
Environmental Protection Agency (EPA) is concerned with the
health and environmental problems caused by leaking underground
storage tanks. EPA is concerned that underground storage tanks
that are not properly installed and managed pose a great risk of
leakage. EPA believes that it is important to prevent leakage.
This is why EPA issued a Chemical Advisory on leaking underground
storage tanks containing motor fuel in September 1984.
EPA is also working on a national survey of about 1,050
facilities where motor fuel is stored in underground tanks. This
survey will tell EPA how widespread the problem of leaking
underground motor fuel storage tanks really is. The survey will
also help answer questions about the best ways to prevent
leaks. Finally, this survey will provide EPA with information
that will help' it decide the types of requirements that are most
likely to be effective in reducing the problem of leaking
underground storage tanks.
While this booklet focuses on the problems of leaking
underground storage tanks that contain motor fuels, EPA
recognizes that underground tanks that store other materials can
also leak. EPA intends to investigate tanks storing other
materials in the future. The term "motor fuels" in this booklet
means all finished gasolines, diesel fuels, aviation gasoline,
and jet fuels. Petroleum products that are not included in the
term motor fuels are fuel oils, kerosene, and residential fuel
oils .
In summary, this booklet will give you information (not
recommendations) about tank leak identification methods;
replacement and repair of underground storage tanks; Federal,
state and local regulations of underground storage tanks; and
insurance for liability. If you have questions about leaking
-6-
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Underground storage tanks that are not answered in this booklet,
you should call EPA at its toll-free hotline number
(800) 424-9346 or, if you are calling from the Washington, DC
area dial 382-3000.
-7-
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LEAK IDENTIFICATION METHODS
A number of methods are available to identify leaking
underground storage tanks and pipes. The information that EPA
has gathered so far on these leak identification methods
indicates that leak identification is not simple and it is not
certain. EPA has also found that there is not one "perfect"
method for leak identification. Each method has good and bad
points. Therefore, EPA is not ready to recommend any particular
method to identify tank or piping leaks,' but wants to inform all
owners and operators about currently available methods. EPA is
undertaking a research project that will study a number of
methods in greater detail.
EPA encourages all tank owners and operators to have an
active leak identification program for every underground storage
tank. In fact, in some localities certain leak
identification steps are required. EPA believes that a
leak identification program does not have to be
complicated or expensive; but, the program does need to
be followed on a regular basis. EPA believes that in
setting up a leak identification program, owners and
operators should consider three basic actions:
1. CHECK the inventory;
2. WATCH for the environmental and
mechanical signs of a leak; and
3. TEST tanks and piping for leaks..
There are a number of leak identification methods that
can be used to CHECK, WATCH, and TEST for leaking
underground storage tanks and piping. These methods
will be described in more detail in this chapter.
In some cases, leaks can be identified right away without
doing additional checking, watching, or testing. The important
thing is that when a tank or piping leak is actually identified,
there should be quick action to inform the proper authorities,
correct the problem, and clean up the leak. Depending on the
-8-
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situation, there may be specific responses to a leaking
underground storage tank that are required by Federal, state, or
local regulations. The chapter in this booklet entitled
"Federal, State, and Local Regulations" 'briefly describes a
number of these required responses. However, if there is a
question about the proper action to be taken in an emergency, the
local fire official should be consulted.
CHECK THE INVENTORY
Simple Inventory Review
Inventory review methods are generally an inexpensive and
relatively easy way to check underground storage tanks for motor
fuel losses. These reviews do require good bookkeeping
and proper tank inventory procedures. Inventory review
methods can be used successfully to identify larger
leaks. Although they may not be able to detect very
small leaks right away, the longer the period over
which inventory reviews are done, tne more likely the
owner or operator will be able to identify small leaks.
EPA has developed inventory review methods for
underground storage tanks that either have mete red
dispensing pumps or do not have metered dispensing
pumps. These inventory review methods are relatively
simple and inexpensive. The only equipment needed to
do these inventory reviews is a dipstick (or gauge
stick), the correct inches-to-gallons conversion chart for the
tank, and (for tanks with metered dispensing pumps) a 5-gallon
"proving can." The cost would be the few minutes a day that it
takes to check the tanks, write down a few numbers, and review
the information.
Several factors make inventory review methods subject to
error (for example, changes in the fuel temperature, errors in
reading the dipstick, or inaccurate fuel dispensing meters).
-9-
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These inventory review methods should be used only as a first
step in discovering a problem. If the inventory is short based
on these review methods, the owner or operator should check the
situation more carefully to determine if the shortage is due to
theft, short deliveries, errors in measurement or calculation
methods. Ruling these problems out, other leak identification
methods should be used to confirm that a tank or its piping is
leaking.
More information on inventory review is found in the American
Petroleum Institute's (API) "Recommended Practice for Bulk Liquid
Stock Control at Retail Outlets" API Publication No. 1621. This
publication is available from API for 15$. For a copy write the
American Petroleum Institute at 1220 L Street NW, Washington, DC
20005, or phone (202) 682-8375.
Inventory Review for Tanks with Metered Dispensing Pumps
This section describes an inventory review method that can be
used by the owner or operator of an underground
storage tank with a metered dispensing pump—
such as a gas station tank or aviation fuel
tank. Using this method, the owner or
operator can determine if daily product levels
in the tank inventory are tending to be
"short" (show a loss of fuel) or "over" (show
a gain of fuel). This loss or.gain could be
caused by a leak, theft, delivery errors, or
errors in measurement.
The inventory review method for tanks with
metered dispensing pumps involves counting the
number of days the inventory is short over a
period of at least 30 days of operation. The
more 30-day periods that inventory records are kept, the better
the chance of identifying a motor fuel leak if there truly is
one. (The chance that the method will incorrectly indicate a
-10-
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leak when there really is none is very small.) If the number of
days of short inventory is greater than the "action number" (to
be described later), this indicates a continuing loss and the
operator or owner should investigate the situation more
carefully. The action number alerts the owner or operator to
take action to correct a problem.
There are three different forms that may be filled out in
order to keep an inventory review: (1) the "Manifolded Tank
System Recording Sheet", (2) the "Dispenser Meter Recording
Sheet", and (3) the "Inventory Review Sheet" (samples of these
forms are provided later in this booklet). The forms that will
be used at each facility will depend on the tank-to-meter-to-
dispenser hookups (or "tank systems") that are shown in
Figure 1. For example, the inventory review for a manifolded
tank system (a tank system with a number of tanks interconnected
by piping) would use all three forms:
0 Stick readings for all of the interconnected tanks would
be recorded on the "Manifolded Tank System Recording
Sheet;"
0 Readings from all of the meters hooked up to those
interconnected tanks would be recorded on the "Dispenser
Meter Recording Sheet;" and
0 Daily totals.from the "Manifolded Tank System Recording
Sheet" and tne "Dispenser Meter Recording Sheet" would
also be recorded on the "Inventory Review Sheet."
Figure 2 is a guide that will show which forms will be needed for
the various types of tank hookups. Blank forms for your use are.
included in Appendix A in the back of this booklet.
The basic steps to be followed in the inventory review method
for metered dispensing pumps are described below:
Step 1; Test the accuracy of the pump meter. Before
starting the inventory review, it is important that the fuel-
dispensing meter is giving accurate readings. A meter that is
reading higher than the true volume pumped may be hiding a large
leak. A meter that is reading lower than the true volume may be
suggesting incorrectly that the tank or piping is leaking. Many
-11-
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Figure 1. Tank-to-Meter-to-Dispenser Hookups
Single tank. Single tank. Custom Blending:
Single tank, sing]e dispensing multiple dispensing 2 tanks, 2 dispensing
unmetered meter meters meters, 1 dispenser
Custom Blending:
2 tanks, multiple dispensing
meters and dispensers
Manifolded Tanks:
multiple interconnected tanks,
multiple dispensing meters
Manifolded Tanks, Custom Blending
-12-
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Figure 2. Tank hookups and the appropriate inventory review forms.
APPROPH IA'1'B INVENTORY REVIEW FORMS
1
1— •
u>
Single 'tank without dispensing meter
Single tank with single dispensing meter
Single tank with multiple dispensing meters
Custom Blending: 2 tanks, 2 dispensing meters,
1 dispenser
Customer Blending: 2 tanks, multiple dispensing
meters and dispensers
Manifolded Tanks: multiple interconnected tanks,
multiple dispensing meters
Manifolded Tanks, Custom blending
DISPENSING METKR
RECORDING SHEET
X
X
X
X
X
X
MANIFOLDED TANK
SYSTEM IIECORIIINR
SIIKKT
X
X
INVENTORY REVIEW SHEET
FOR TANKS WITH MRTKRRH
DISPENSING PUMPS
*
X
X
X
X
X
X
INVENTORY REVIEW SHEET FOR
TANKS WCTMOIIT METKRED
DISPENSING PUMPS
X
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localities have passed regulations that specify how frequently
meters must be checked for accuracy. It is important to know the
local regulations on how frequently the meters are to be checked.
The pump meter check is done by dispensing 5 gallons (as
shown by the pump meter) into a 5-gallon
proving can. A 5-gallon proving can is a
container that is marked at the level
where, when filled with fuel, it will
contain exactly 5 gallons. Proving cans
may be purchased from local distributors
of petroleum marketing equipment. The
names of these distributors are ' found
under the heading "Service Station
Equipment" in the Yellow Pages.
The fuel level in the proving can is
then examined to see whether it is above
(+) or below (-) the 5-gallon mark on the
proving can. If the meter is inaccurate,
the error should be measured and recorded as described in Step 2.
Information can be found in API Publication 1621 which presents a
procedure for testing the accuracy of dispensing meters. If the
meter is not accurate, the meter should be checked by the State
or local weight and measurement office.
Step 2; Record inventory information
daily; Dispensing Meter Recording Sheet
and Inventory Review Sheet Part A. The
daily inventory information is based on
dipstick measurements. A dipstick (or
gauge stick) is a stick that is usually 6
to 10 feet long and has been marked off at
certain regular distances (generally 1/8
or 1/4 inch). The dipstick is slowly
lowered straight down to the bottom of the
tank, always lowering the same end of the
stick into the tank. It is important that
-14-
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the dipstick be carefully lowered into the tank, especially if
the tank is fiberglass, to avoid rupturing the tank. An API-
recommended procedure for taking dipstick measurements
("sticking") of the fuel in a tank and for detecting water in a
tank is given in API Publication 1621.
A water-finding paste can be applied to the bottom of the
dipstick to tell if water may be leaking into the tank. This
paste will not react with the motor fuel, but will change color
in water. If this paste turns color when inserted into the tank,
further investigation should be made to determine the source of
the water in the tank.
When the dipstick is withdrawn from the tank, the mark at the
top of the wet area is read. Charts are available that show
conversions from dipstick measurements into gallons of motor fuel
in the tank. These inches-to-gallons conversion charts are
specific for each tank based on the tank's diameter and length.
The correct chart for a specific tank must be used to accurately
convert dipstick measurements to gallons of fuel. For a tank
that has been repaired by lining, it is necessary to use an
updated conversion chart.
The daily inventory information is recorded in the following
way. On the Inventory Review Sheet for each tank (see sample,
Figure 3), or on the Manifolded Tank System Recording Sheet for
manifolded systems (see sample, Figure 4), record the dipstick
inventory information. On the Dispensing Meter Recording Sheet
(see sample, Figure 5), record at the end of the day the number
of gallons dispensed (daily sales) for each meter hooked to the
same tank or manifolded tank system, based on the present day's
and preceding day's closing meter readings. Enter also on the
dispensing meter recording sheet the daily line totals, and
transfer that number to Column 8 of the Inventory Review Sheet
for that tank or manifolded system. Finally, complete the
Inventory Review Sheet (Columns 9 and 10) to show the daily loss
-15-
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Figure 3. Sample inventory review sheet
for tanks with metered dispensing pumps.
TANK NO.
PROVING CAN _
METER CHECK
PART A
date
Opening
Dipstick
Inventory
Dal Iverles
Total
[Column 21
plus
ICol""" U
Column i
C 1 os 1 ng
Dipstick
Inventory
(Inches)
Column 6
Closing
Dipstick
Inventory
(oal Ions)
Column 7
Gone from
Tank
[Column 41
minus
[Column 61
Column 8
Meter Sales*
(gallons)
(from meter
sheet)
Column 9
Column 3 less
than (-) or
greater than
< + > Column 7
Column 10
Columns 7 &
8: Subtract
Smal ler from
Laroer
6604
/7
/?/? i
70
fe-tr I WAS
o
(*-£ \ 33£3
/
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Figure 4. Sample manifolded tank system recording sheet.
M.nni f.il.lr.,1 T.mk Syilo,,, |.n.
•rypn of p,,ei Diese (
\ „ , 1
- '
, \1lf
'
i
4
1/t
1/1
T.ink
M 1
A. Ofienhi'i stick (.|il'i.) ( Yoster.l.iy's linn r.) \3tTvO
B. Del i ver ies (t.al of fuel in Link (AMI)
D. Closimj si ii:k ( in, -In--;)
O
3460
T.ink
T.mk
H 1
T.mk
I A
ZfSOl 327
1.1 t*r
lft3W\ y-m\ w'i
F.. ClosilK) Stl'Tk (,|,1|S.) \$()5D
F. Fuel ijoue from t.ink (.j.ils.) (C-F.)
A. Open i ii'| Rlic:k (ij.ils.) ( Yost .enl.iy ' s line R)
B. Deliveries (q,ils.)
C. Tolal of fuel in Link (AMI)
D. Closin'j si i,:k ( incli--.;)
E. Cliislivi st ick (i|-ils . )
F. Fuel ijone from Link (.|.ils.) (C-F.)
2ysz>
410 \ 530
3ott
0
V3
Z57]t>
V8t>
A. Open I in) at irk (i).ils.) ( Yes tenl.iy ' s line P:) j i^JO
B. l)e 1 iver les (ijfll •-, . )
C. Total of fuel in Link (AMI)
n. Closing sLIrk ( ini-h."!)
i ^" ^1 f\
tit
E. Closiin) sLlck (i).il!i.) | ~W£D
F. Fuel ijone from Link (,|.ils.) (OF.)
A. Oi>piiiii<) si li-k (,|,I|T.) ( Y"sL>r.l.iy' s line K)
B. IX^liveries (,jrils.)
C. Totrfl of fuel in Link (AMI)
D. Closini) sllfk ( i n,'ll'"5 )'
K. Closin.) st.i,;k (i).il'!.)
F. Fuel yone from Link ('|.il:.) (OK)
LZb
272S)
5'tfS\
J*/5Z>| Zr?2$\
D
WO
51,0
WO
D
37^\
ti$Q
5l£\
£l£b
Z000\ ISOt)
3V?o\J6>£t)
51 fT\ ' /__
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(ffiO
*7 ^y c "~ i
/ 0^^ |
T.mk
« r.
T.ink
«c
*>
T.mk
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t
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M n 1 'i> > i i ) ^
B t> 1 1 * M il I .1
K
\
\
/*/55~
/6/S~
11 &
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Figure 5. Sample dispensing meter recording sheet.
Tank No. / -^3. ;
or, if manifolded tanks, tank system no.
(Sheet 1 of 5)
Type of fuel
I\ \ Meter I Meter I Meter 1 Meter
Date 1 Meter Recordings in Gallons | #1 J S2 | 03 ] S4
1
2
3
4
5
6
H
£-Jt
6-5"
G. Today's Closincj Meter | 53? W j W56 | ^V"A/0
H. Yesterday's Closing Meter
I. Gallons dispensed (G-ll)
S33// | yn*0| *3fj?f
if-11 | 5"J6| Tll\
G. Today's Closing Meter | 5"V535 | 52)^^3 j ^^2>2 |
H. Yesterday's Clositu, Meter | S~37 &A | ^f^Si\ ^A/0|
I. Gallons dispensed (G-ll)
55Z)j VS7! ^/P|
G. Today's Closing Meter j ^V^ | 57073 | ^ S^a|
H. Yesterday's Closing Meter 1 5^33 | S~0V*3| £Y*2l2|
I. Gallons dispensed (G-H)
V/Ol ^301 fyO\
G. Today's Closing Meter | j j
II. Yesterday's Closing Meter J j [
I. Gallons dispensed (G-ll)
\ \
G. 'today's Closing Meter J j j
II. Yesterday's Closing Meter | j |
1. Gallons dispensed (G-H)
1 1
G. Today's Closing Meter ^ [ |
II. Yesterday's Closing Meter J j j j
1. Gallons dispensed (G-ll)
I 1
Meter
#5
Meter
#6
Meter
#7
Meter
#8
Line I*
Totals
X
|X
/77Z
X
|X
!/*#
x"^
X
!/r00
X
iX
X
X
x"
IX
CO
I
* Transfer I.ine I totals to Column H of Inventory Review .Sheet
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Figure 6: Action numbers for tanks
with metered dispensing pumps.
30-Day Period^- Action Number2
1st 20
2nd 37
3rd 54
4th 69
5th 85
6th 101
7th 117
8th 133
9th 149
10th 165
llth 180
12th 196
ISO-business day inventory period.
Cumulative count of short (-) daily inventories. Enter
appropriate number on Inventory Review Sheet (Part B, Line 4)
-19-
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or gain in motor fuel inventory for the given tank or manifolded
tank system.
Step 3; Review inventory results; Inventory Review Sheet
Part B. At the end of each 30-day inventory period, a summary of
the total period's inventory outcome is calculated in Part B of
the Inventory Review Sheet. The purpose of this step in the
inventory review method is to find out whether daily inventories
are actually short and further action is needed to determine why
they are short. Statisticians have calculated the number of days
showing shortages during one or more 30-day periods that should
alert the owner or operator to take action to find the source of
the problem. The problem could be theft, bookkeeping errors,
inaccurate meters, delivery errors, or leaks in the tank or
piping. These action numbers for successive 30-day periods are
shown in Figure 6.
Fran Column 9 of the Inventory .Review Sheet (see Figure 3),
count the number of days the inventory measured short (count all
the minuses) during the period. To this number add the
accumulated number of days of short inventory (all the minuses)
from the previous period's sheet and record the total on
Line 2. Compare this new total (Line 3) with the appropriate
action numbers from Figure 6. If this new total (Line 3) is
higher than the action number (recorded on Line 4) for the
period, a routine daily loss may exist.
Inventory Review for Tanks without Metered Dispensing Pumps
For underground storage tanks without metered dispensing
pumps, such as many farm tanks and other small tanks, the problem
of using inventory review to identify fuel losses is complicated
by knowing only imperfectly how much fuel is pumped from a
tank. This means that the inventory review must be based on
stick readings alone. One answer to this problem is to install a
dispensing meter. However, EPA has developed the following
inventory review method for use with tanks that do not have
-20-
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meters on the dispensing pumps. In order to use this method, the
tank owner or operator will need a dipstick (or gauge stick) and
the correct inches-to-gallons conversion chart for the specific
type of tank.
The steps involved in the inventory review method for tanks
without metered dispensing pumps are as follows:
Step 1; Stick the tank for a beginning reading. The method '
for sticking the tank is the same as described for sticking a
tank with a metered pump (see Step 2 under Inventory Review for
Tanks with Metered Dispensing Pumps). The beginning (start)
reading will be used to figure out the first measurement of
loss. The tank stick reading can be done at 'any time. Enter the
"start" stick reading on the Inventory Review Chart for Tanks
Without Metered Dispensing Pumps (see sample, Figure 7) in the
column marked "Dipstick Reading (inches) After."
Step 2; Stick the tank immediately before and after each
withdrawal. Record on the Inventory Review Chart the number of
inches and gallons of motor fuel in the tank before and after the
withdrawal. This step should also be done each time before and
after the tank is filled.
Step 3; Determine the loss between withdrawals. Subtract
the number of gallons in the tank immediately before the present
withdrawal from the number of gallons present immediately after
the previous withdrawal and record the number on the Inventory
Review Chart. The difference represents a volume loss or gain of
liquid in the tank during the period between withdrawals, plus
any measurement error. If the amount of liquid actually in the
tank is greater than what has been calculated, it may be the
result of dipstick reading errors, or of water leaking into the
tank.
Step 4: Determine the total loss. Determine the total gain
or loss in motor fuel by adding the present loss between
withdrawals to the last recorded total loss. Enter this number
in the total loss column.
Step 5; Compare the total loss with the action number. If
the number in the total loss column is greater than the
-21-
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FiguLe 7. Sample invenLoiy Leview chai_t for tanks
without meteLed dispensing pumps.
i
NJ
WITHDRAWAL OR FILL
Number
Start
1
2
3
4
5
6
7
8
9
10
11
12
Date
fc-Z-f
&-V-8'/
[_ 6-/0-*f
fc-/S -fV
1
DIPSTICK READING LOSS BETWEEN
(INCHES) (GALLONS) | WITHDRAWALS1
Before After
xx | W VL
5V'/V | £Z*/f
5Z | 5Z>'/z-
^^ I f*5^
L J_ J
I
Before After I
TOTAL ACTION IS THERE
LOSS NUMBER2 A LEAK?3
xx j 1oS \ xx | xx J xx
Yes
XX
lo7 \ 17
/6
^o
3J I ^?^"
X
U___L_^ _L _ _L . _i 1
L J J i
I I I I
I
III! i
I I I I
I I I I
III!
till
i I I I
L
No
XX
X
X
"
L_ J [_
l_ J 1
Gallons after last withdrawal or fill minus gallons before this withdrawal or fill.
From Action Number Table for Tanks without metered pumps.
There is a leak if the total loss for the qiven number of withdrawals and fills is greater than the action number.
-------
Figure 8: Action numbers for tanks
without metered dispensing pumps.
Withdrawal Number Action Number
1 14
2 20
3 25
4 29
5 32
6 35
7 38
8 40
9 43
10 45
11 47
12 49
-23-
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appropriate action number (Figure 8), there has very likely been
an actual loss in fuel.
For best results with this inventory review method, there
should be several days between withdrawals. If any sign of a
problem is seen, action must be taken to identify and correct the
problem. A blank Inventory Review Chart is included in the back
of this booklet as Appendix B.
Automatic Inventory Systems
In addition- to the above simple inventory review methods
which are accomplished manually, there are inventory testing
methods which are automated and usually operate continuously.
Automatic inventory systems can serve many functions. Some
systems are available which electronically check the motor fuel
level in the tank continuously, record deliveries made to the
underground storage tank, and check for leaks and other sudden
large losses.
Another type of automatic system checks for the presence of
motor fuel in the ground outside the tank and alerts the tank
owner or operator if motor fuel appears. Automatic systems that
are placed outside the tank only provide information when a leak
is detected, and do not provide daily information on fuel levels
in the tank.
Automatic systems have the advantage of reducing human error
in leak identification. Automatic inventory systems can more
easily identify long-term changes in the tank environment, such
as those caused by a slow leak, since they are continuously
checking the tank. However, these systems are generally more
expensive than other leak detection methods and may have
continuing costs, such as electrical costs, that other methods do
not.
-24-
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Computerized Inventory Review Methods
Computerized reviews of inventory records can also be done.
This computerized review considers a number of factors, including
environmental factors, that can be used in deciding whether an
underground storage tank is leaking.
FOR ENVIRONMENTAL AMD MECHANICAL SIGNS
When motor fuel is lost from an underground storage
tank, serious environmental and safety hazards may be
created. These hazards caused by leaking underground
storage tanks or piping may not be detected for months
or even years. If the leak is not properly taken care
of, it may become widespread, making it more difficult
and expensive to clean up. A careful watch for
environmental and mechanical signs is helpful in
identifying a leak.
Environmental Si>gns
As a part of the everyday operation
of an underground storage tank, the
owner or operator of the tank should
watch for certain signs which would
identify a tank leak. It may be
possible to identify leaks at an early
stage by regularly inspecting the
piping and pumping equipment, and by
watching for signs of leaking motor
fuel in the surrounding area. The
following are some environmental signs
that may indicate that a tank is
leaking :
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Odors of gasoline, or other motor fuel, in the soil near
the tank may be a sign of a leaking tank or piping. These
odors may also be caused by motor fuel spills that
happened during deliveries or when filling up vehicles.
The odor or presence of motor fuels in underground
structures such as basements and sewers is a sign that an
underground storage tank may be leaking.
Careful watch of the plant
life located near an
underground tank is another
way to identify a leak.
Plants located on property
near the underground tank may
not grow, may look sickly, or
may even die. In particular,
the owner or operator should
watch for clumps of plants
showing these signs.
Motor fuel found in drinking
water wells of neighboring
properties is a sign that a
tank is leaking somewhere. Reports of motor fuel in a
neighboring drinking water well should start the owner or
operator looking for other signs of a leaking tank.
Motor fuels found as a sheen on the surface of the water
found in streams, rivers, and lakes can be a sign of a
leaking underground storage tank.
Mechanical Signs
Leaks can also be identified by observing the way the
dispensing system is working. A few common dispensing system
problems and their probable causes are listed below.
0 Hesitation in delivery of motor fuel dispensed by the
suction pump located at the dispenser may oe a sign of a
leak in the piping. This hesitation may also be caused,
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however, by a leaking valve or, in warm weather, by vapor
lock.
0 A rattling sound and irregular fuel flow in a suction
pumping system are signs that air is entering the
dispensing system and mixing with the motor fuel. Air
could be entering the system through a loose fitting or a
hole in the piping.
0 In a remote (submerged) pumping system, meter spin without
motor fuel delivery may be a sign of a piping leak.
0 Less motor fuel in a tank than the records show (a
shortage) is a sign of a number of problems. Besides
being a sign of a leaking tank, it could be a sign of
problems in bookkeeping, problems in the metering of the
motor fuel, theft, large decreases in the temperature of
the motor fuel in the tank temperature, under-deliveries,
cross-pumping to another tank, or piping leaks.
0 More motor fuel in a tank than records show (an overage)
is also a sign of a number of problems. It could be a
sign of water leaking into the tank. It could also be a
sign of problems in bookkeeping, problems in the metering
of the motor fuel, large increases in the temperature of
the motor fuel in the tank, over-deliveries, or cross-
pumping from another tank.
0 Continuing differences between the recorded amount of
motor fuel received and motor fuel dispensed may be a sign
of an inaccurate meter, theft, a leak in tanks or piping,
use of the wrong inches-to-gallons conversion chart, or a
consistent delivery error.
0 Large differences appearing only and regularly between the
delivered amount of fuel noted on the invoice and the
measured amount in the tank after delivery may be a sign
of a leak in the fillpipe, a delivery error, or a dipstick
reading error.
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Manway Inspections
Underground storage tanks can also be
/
watched for signs of leaks by doing
manway inspections. A manway is an
opening in a tank that is large enough
for a person to enter the tank. Some
tanks are made with manways, others must
have manways put into existing tanks.
The following general steps must be taken
to put a manway in an existing tank:
empty the tank, remove the concrete or
asphalt pads and backfill material, cut a
hole in the tank top, and weld an
entrance cover on the tank. Once this
has been done, the tank is cleaned and
then a person can enter the\tank to
inspect it. ,
A manway is generally put into a
leaking existing tank that will be repaired rather than
replaced. However, once the manway is installed it can be used
in a routine cleaning and inspection program.
TEST the TANK AND PIPING
When any of the various inventory review
methods or environmental or mechanical indicators
suggest that an underground storage tank may oe
leaking, tank and piping tests should be
considered. The choice of a tank and piping test
method requires the owner or operator to make a
number of decisions. The owner or operator
generally makes these decisions based on what is
learned from checking the inventory, watching for
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environmental and mechanical signs of a leak, and knowledge of
the tank and piping system.
EPA is looking for tank testing methods that are best suited
for the national survey of underground fuel storage facilities.
In finding the best tank testing methods for the survey,
different questions and different needs face EPA than face the
owner or operator of a tank. It would be difficult, if not
impossible, to name one method that would be the best method for
all situations. However, the factors EPA considered in
evaluating the methods for the EPA national survey of underground
storage tanks containing motor fuels are listed below:
° Versatility. Is the method designed to identify leaks in
tanks only, piping only, or both tanks and piping?
0 Nuisance factor. How much will the test method disrupt
facility operations? Will the fuel pump have to be shut
down? What is the possibility of property damage? Will
the tank have to be completely full (or empty) before the
test can be run?
0 Performance. Is the test accurate enough to identify
small leaks consistently? Can the equipment oe operated
under various weather conditions (for example, very high
or very low temperatures)?
° Cost. How much does the method cost per test? Are there
special labor costs? Is the equipment easy to transport
to many locations?
0 Equipment and staff requirements. Is the equipment to
conduct the test available when it is needed? Are there
special training requirements? Is the equipment safe to
use? What are the capabilities and experience of the
testing crew?
0 Quality assurance. Are the results of the tests reliable?
0 Legal requirements. What are the Federal, state, and
local requirements concerning leak identification?
In general, tank testing can be costly and inconvenient.
Tank testing, however, can be very helpful in identifying a leak
before it becomes a bigger problem. While there is not one
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"perfect" method for tank testing, there are a great number of
test methods that each identify motor fuel losses in slightly
different ways. It is not possible to list and evaluate all
known methods in this booklet. However, what follows is an
explanation of the various characteristics of a number of
different kinds of tank tests. EPA has divided these tests into
two broad categories: external tests and in-tank tests.
External Tests
Some tank tests are run
outside of the tank and piping
to look for leaked motor
\
fuel. There are a number of
types, of external tests; but
the groundwater monitoring
wells are the most common type
of external test. These wells
are also called observation
wells or in-well monitoring.
The number and location of
groundwater monitoring wells
and the equipment used to keep
a check on these wells depend
on several factors, including
the soil conditions, the movement of the groundwater, and costs
of drilling and -materials. A typical monitoring well will reach
2 feet below the bottom of an underground storage tank. Samples
are collected from the wells and checked for motor fuel. These
wells may also be checked using automatic sensors. In addition,
a simple and effective way to check wells for leaked motor fuel
is to coat the measuring end of a dipstick with hydrocarbon
detection paste. The pasted end of the stick is then inserted
into the monitoring well. If the paste changes color, motor fuel
is in the well.
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External tests are designed to tell only if there is a leak;
they do not determine the leak rate. The costs for external
tests are similar to the costs for other types of tests, but the
disruption to normal operations for external tests may be much
less than for other types of tests.
Another method which has been used to look for motor fuel
outside of the tank is soil core analysis which requires the
drilling of a hole much like the drilling for monitoring wells.
The soil core is analyzed by a laboratory for motor fuel
entrapped in the soil. Another method looks for motor fuel
vapors that have traveled from a leak to the soil surface.
Other methods include surface geophysical methods. Generally
experimental and very technical, these methods include: ground
penetrating radar, seismic determination, electromagnetic
induction, resistivity, metal detectors, magnetometers, and X-ray
fluorescence .
Some external tests add freon tracers to underground storage
tanks. If a leak is present in the tank or piping, it escapes
into the ground where it is easily detected by special
instruments called gas chromatographs. A similar method
pressurizes the tank with helium. As the helium escapes through
a hole or crack, it is detected on the surface by an instrument
called a mass spectrometer.
Automatic, or continuous electronic, tests generally use
permanently installed leak identification sensors. These sensors
regularly check for fuel vapors or liquid that comes in contact:
with the sensor after fuel has leaked from the tank.
The costs for external tests vary widely. The basic cost of
digging a well, for example, will depend on the drilling depth
and the diameter of the well. When monitoring wells are
installed during construction of new facilities, the installation
is easy to do and the cost is low. Permanently installed
equipment provides the advantage of ongoing tests for leaks.
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1
'Of
In-tank tests
Most of the in-tank tests
are done by outside
companies. This is Decause
the equipment to run these
tests is generally very
expensive to purchase and
often requires trained
technicians to run the test.
In-tank tests can be done on a
routine basis or only when
other factors suggest that
there is a leak.
In-tank tests use
equipment that is placed
directly inside the tank or
piping. These tests differ in
the information that is
obtained. Some tests can
determine how fast the tank is
leaking; others can only tell whether the tank or piping is
leaking. Some may be continuous if installed in a separate tank
opening; others can tell only the condition of the tank on the
day it is tested. In spite of all the differences among in-tank
tests, there are some similarities. Most in-tank tests can
identify a leak in a relatively short period of t ime-'-gener ally 2
to 4 hours. Most in-tank tests also require some set-up time,
which can be longer than the test period. This time means a
major shutdown for some owners or operators.
All these tests are subject to such factors as evaporation,
condensation, and changes' in temperature in the motor fuel in the
tank; changes in the shape of the tank as a result of adding
motor fuel for the test; and changes in level caused by air
pockets, vibrations from traffic, and groundwater or soil
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moisture. in addition to shutdown time, these tests can increase
an existing leak, affect the quality of the motor fuel, create an
explosion hazard if done improperly, or even fail to identify a
leak.
Quantitative in-tank leak tests measure the changes in the
volume of fluid in the tank due to a leak. These tests can
determine how many gallons of motor fuel are leaking from a tank
in an hour. Most of these quantitative leak tests measure either
the level of motor fuel in the tank or changes in pressure within
the tank. There are a number of ways to test the fuel level or
pressure.
Some devices are still in the experimental stage or have not
been used on a widespread basis. one such test method is the
laser interferometer which measures the change in the height of
the motor fuel in the tank with lasers. Other new techniques use
acoustics, or sound waves, to identify holes or cracks in the
walls of the tank. Other acoustic methods can measure the sound
of fuel escaping or entering the tank.
The tank tests discussed above cost anywhere from several
hundred to a few thousand dollars per tank. The cost varies
depending on such factors as travel time for testing technicians,
availability of equipment, whether and how long the facility must
be closed to run the test, whether a full tank is required to run
the test, and the conditions under which the test must be done.
Test requirements vary. Some need full tanks; others can
operate at any fuel level. Some use equipment that is easily
movable from tank to tank;\otners require specially equipped
J
trucks for transportation from site to site. All quantitative
leak tests, however, need electricity to run the testing
equipment.
A Few Words About the Safety of In-tank Test Methods
The National Fire Prevention Association (NFPA) does not
recommend pressure testing with air or explosive gases. This is
because of the chance of causing a tank rupture or an
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explosion. However, there are some safe in-tank tests that use
gases without using pressure to identify a leak. Consult a local
fire official if there are any questions concerning the safety of
a tank test method.
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UNDERGROUND TANK AND PIPE REPLACEMENT AND REPAIR
The major cause of leaks from tanks and piping may be the
improper installation and maintenance of the equipment. That is
why the proper installation and maintenance of tanks and piping
is essential to prevent leaks.
The other major cause of leaks in underground storage tanks
may be corrosion of the tank and piping. Therefore, if corrosion
can be slowed or stopped, many leaks from steel underground tanks
can be prevented. The two most common ways of preventing
corrosion are: (1) cathodic protection of steel tanks, and
(2) the construction of tanks with corrosion resistant
materials. These are discussed in this chapter.
If a tank or piping system leaks, it should be replaced or
repaired. Replacement alternatives include using double-walled
tanks and other tanks constructed of a number of materials, such
as fiberglass-reinforced plastic and fiberglass-coated steel. In
some cases, a leaking tank may be repaired instead of being
replaced. Tank replacement and repair is also discussed in this
chapter .
CORROSION
Corrosion is an electrochemclal
change in metal. Corrosion occurs
when an electrical current flows
from the metal of the underground
storage tank or piping into the
surrounding soil, carrying with it
particles of metal (called ions) so
small that they cannot be seen. The
visible results of corrosion are
rusted areas or holes in the
metal. The rate of corrosion
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depends on factors such as soil characteristics, the presence of
other metals nearby, the presence of other underground electrical
systems, characteristics of the tank and piping system, and high
soil moisture or high groundwater.
STEEL TANKS
Unprotected Steel and Asphalt-coated St®«l Tanks
The most common type of tank used for underground storage has
been the unprotected "bare" steel tank. Bare steel tanks have
been known to leak in as littl® as two years, depending on
factors such as soil conditions and installation practices.
In order to help protect steel tanks from corrosion, steel
tanks may be coated with a thin coating of a material such as
asphalt, coal tar epoxy, urethane, or resin. This coating
interrupts the small electrical current flowing from the tank to
the soil and thereby prevents corrosion. However, pinholes or
cracks in these coatings will lead to areas of pinpoint corrosion
on the tank. These coatings may also be damaged during shipping
or installation or, in some cases, from contact with motor fuel.
Cathodic Protection
Two types of systems are available to provide cathodic
protection to steel underground storage tanks. These are
impressed current systems and sacrificial anode systems.
In the impressed current system, AC current from the site
electrical system is converted to DC current by a rectifier.
Current flows from the rectifier to a metal anode, through the
soil, to the tank or pipe, and back to the rectifier. Impressed
current systems can protect both the tank and piping from
corros ion.
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The required amount of current can be adjusted to the local
conditions and the facilities to be protected. This system can
be used on existing as well as new tanks. Maintenance involves a
periodic check of the current meter to be sure that the system is
operating properly. Impressed current systems must be supplied
with power and operating at all times.
A sacrificial anode system is another way to prevent
corrosion by inducing an electrical current flow from the anode
to the tank (this system does not use an external power
supply). -A sacrificial anode, usually made of magnesium or zinc,
is connected or attached to the tank. The metals in the
sacrificial anode have a higher electrical potential than the
steel tank. Therefore, an electrical current will flow from
these anodes to the tank, causing the anodes rather than the tank
to corrode. As the name suggests, the anode sacrifices itself to
protect the tank.
This system may be used to protect the tank and the piping
from corrosion. The advantage of the sacrificial anode system is
that an external power supply is not required. However, the
anodes must be monitored and replaced as they corrode. Also, the
anodes may not be able to produce an adequate electrical current
to prevent tank corrosion under some soil conditions.
Proper installation and maintenance of any cathodic
protection system is important to protect the tank and piping
fron corrosion. A check of the cathoaic protection system should
be made by a qualified corrosion engineer when the system is
installe'd to make sure that the system is providing adequate
protection. Periodic checks should be made to be sure that the
tank and piping are continuously protected from corrosion.
Steel Tank Repair
MOST: steel tank repairs are done by lining the interior of
the tank with epoxy-based resins or some other coating that is
compatible with fuel products. Before the tank can be repaired,
all fuel must be removed, and the tank must be completely emptied
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of all vapors. An entry hole must be cut into the tank so that
workers can get inside to thoroughly clean the inside tank
surface and mend any holes or cracks. These procedures are
necessary to make sure that the lining material will adhere to
the interior surface of the tank. Before putting the tank back
into service, the tank should be tested to be sure that all leaks
are repaired.
Lining a tank is often done to extend a tank's life; however,
there are cases in which tanks should be replaced rather than
repaired. For instance, API does not recommend the lining of a
tank that has open seams more than 3 inches long, perforations
larger than about 1-1/2 inches in diameter, more than
5 perforations per square foot of surface area, or more than 20
perforations per 500 square feet of surface area. Some
localities have certain restrictions on repairing tanks. The
)
local fire official can be consulted to find out what these
restrictions are.
Repair of the tank and piping equipment may involve some
hazard and may require special training and equipment. In some
localities, only specially licensed mechanics can work on motor
fuel storage equipment.
FIBERGLASS TANKS
Fiberglass is resistant to electrochemical changes.
Therefore, fiberglass tanks eliminate external corrosion without
the need for special corrosion prevention systems. However,
careful attention should be paid to fiberglass tank installation
to avoid tank rupture from uneven" soil loading. In general,
underground storage tanks, especially fiberglass tanks, can be
forced upward as the water table rises. Tanks have been known to
rupture when placed under this kind of pressure.
Recently, concerns have been raised that the fiberglass
materials originally used in tanks are not suited for use with
alcohol-blended fuels, particularly methanol. However, with the
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recent trend in the gasoline industry to boost octane levels with
alcohol blends, fiberglass tanks lined with a resin resistant to
alcohol blends are now available.
DOUBLE-WALLED TANKS
Double-walled tanks consist of
one tank nested inside another
tank. In addition, an automatic
leak identification system may be
placed between the inner and outer
tanks to signal the presence of any
water or hydrocarbons in the cavity
between the tanks. Double-walled
tanks are subject to the same
problems described for fiberglass
and steel tanks; however, the risk
of leakage is reduced by the inner
tank and by the leak identification
system.
There are three basic types of
double-walled tanks: double-walled
steel tanks, double-walled coated
steel tanks, and double-walled fiberglass tanks. Double-walled
fiberglass ana double-walled steel tanks are the most common
types of tanks; the double-walled fiberglass-coated steel tank
has only recently been introduced.
PIPING
Underground storage tank piping may present a higher-
potential for leaking than the tank itself. Piping leaks can be
caused by corrosion, misalignment, stresses from temperature
change, freezing and thawing, loads from traffic, and settlement
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of backfill. The same factors that lead to corrosion in tanks
lead to corrosion in the piping. That is why preventing and
identifying leaks in the piping is just as important as
preventing and identifying leaks in the underground storage tank.
A number of pipes made of corrosion-resistant materials are
now available. For example, fiberglass-reinforced plastic pipes
are available that are flexible as well as corrosion resistant.
Piping may also be cathodically protected. Double-walled pipes
are also available, and some of these are equipped with
monitoring devices between the inner and outer walls.
COST AND WARRANTY INFORMATION
Figure 9 presents cost information for underground storage
tanks by material of construction. To these costs are added
transportation and installation costs of 35,000 to $10,000 pel-
tank. On this basis, the total installed cost of fiberglass
tanks ranges from 20 to 25 percent higher than that of steel
tanks. The fiberglass-coated double-walled steel tank costs
approximately $11,000 more than an unprotected steel tank.
In addition to the cost of the tank, the warranty on the tank
should be considered when selecting a tank. Every warranty has
its own limitations and conditions, so the warranty should be
read carefully before the tank is purchased. Some warranties
offer a prorated refund, some warranties refund the original
purchase price, and others replace the tank.
However, these warranties have some features in common. In
general, fiberglass tanks are warranted against defects in
materials and workmanship for one year and against rust for 30
years. Structural failure is not generally covered under the
terms of the warranty.
Steel tanks manufactured under the specifications of the
Steel Tank Institute (sti-P-j®) are warranted against external
corrosion for 20 years, against defects in materials and
workmanship for one year, and against structural failure for the
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Figure 9: Underground storage tank costs.
Average Cost for new
Tank 10,000 gallon tank1
Asphalt-coated steel $3,000
Fiberglass-coated steel 6,000
Fiberglass-coated,
double-walled steel 14,000
Epoxy-coated steel,
sacrificial anode 4,500
Fiberglass (regular) 4,500
Fiberglass (alcohol
blends) 5,000
Tank re lining (all
steel tanks) 5,000
•'•Most common size; does not include installation
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life of the installation. Fiberglass-coated steel tanks have a
warranty period ranging from 20 to 30 years.
FINANCING FOR REPAIR AND REPLACEiMENT
Small businesses can apply to a number of lending sources for
long-term loans to cover the cost of pollution control
equipment. These sources include: nationally administered
Federal programs; locally administered Federal, state, and local
programs; and private sources. Upon approval, these loans may be
used for underground storage tank replacement and repair.
EPA has assembled fact sheets describing the sources of
financing for pollution control loans. These fact sheets answer
commonly asked questions about each of the financing programs,
such as eligibility criteria, loan limits and conditions, and
application procedures. Copies of the fact sheets can be
obtained by calling EPA's toll-free Small Business Hotline at
800-368-5888 and asking for "Assistance Programs for Pollution
Control Financing."
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FEDERAL, STATE AND LOCAL REGULATIONS
FEDERAL REGULATIONS
Two sets of Federal regulations deal with storage of
petroleum in underground tanks. EPA has included underground
motor fuel storage tanks in regulations issued for oil pollution
prevention under the Clean Water Act. The Occupational Safety
and Health Administration (OSHA) has included underground motor
fuel storage tanks in its regulations dealing with flammable and
combustible liquids.
Under EPA's Oil Pollution .Prevention regulation (40 CFR Part
112), owners or operators of facilities that have an underground
storage tank containing 42,000 gallons or more of oil (including
motor fuel),, and that, due to their locations, could release oil
on navigable waters in quantities that could cause a sheen, must
prepare and carry out a Spill Control and Countermeasures Plan
(SPCC). Owners or operators of these facilities must also
install corrosion protection systems for underground storage
tanks and test the underground tanks for leaks at least every
5 years. Any releases of oil from leaking underground storage
tanks reaching navigable waters and causing a sheen on those
waters must be reported to the National Response Center at
(800) 424-8802 toll-free, the nearest U.S. EPA Regional Office,
or the nearest U.S. Coast Guard district office as required by
the oil discharge regulation (40 CFR 110).
Under OSHA regulations (29 CFR 1910.106), standards have been
issued for the control of flammable and combustible liquids in
underground storage tanks. Among these regulations are standards
for the installation of underground tanks. OSHA regulations
require that underground tanks be set on firm foundations and
surrounded with at least 6 inches of noncorros ive, inert material
such as clean sand, earth, or gravel that has been tamped in
place. In addition, tanks must be covered with at least 2 feet
of earth or must be covered with at least 1 foot of earth and
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covered with a slab of reinforced concrete at least 4 inches
thick. The regulations state that at a minimum underground
storage tanks must: use protective coatings or wrappings; use
cathodic protection; or be constructed of corrosion-resistant
materials.
OSHA testing requirements for underground petroleum
(including motor fuels) storage tanks state that all tanks must
be tested for strength before they are placed in service. The
American Society of Mechanical Engineers (ASME) code stamp, the
American Petroleum Institute (API) monogram, or the listing mark
of the Underwriters' Laboratories, Inc. (UL) on a tank show that
the tank meets the strength test requirement. OSHA regulations
also require that before being used, underground tanks must be
tested for tightness. In addition, OSHA regulations require that
accurate inventory records be maintained and reviewed for
possible signs of leakage from tanks or piping.
STATE AND LOCAL REGULATIONS
A numoer of states and localities have passed legislation or
issued regulations for the storage of motor fuels in underground
tanks. Approximately 30 states have legislation and regulations
for the control of storage of hazardous materials including motor
fuels in underground tanks. Although state standards vary
widely, they are generally at least as strict as those practices
recommended by the National Fire Protection Association (NFPA).
The NFPA recommends practices for handling underground
leakage of flammable and combustible liquids in Standard 329.
While the practices recommended for handling flammable and
combustible liquids (Class I liquids) are not law in their own
right, many states and localities have adopted these
recommendations as a framework in the development of their
regulations.
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The following paragraphs describe in a general way the NFPA
and/or current state standards for the underground storage of
motor fuel.
Permit Requirements. There are no NFPA recommended mandatory
permits for owners of new motor fuel storage tanks. However, the
Uniform Fire Code (UFC), used in eight states, does require
permits to store, remove, abandon, or temporarily place out-of-
service tanks storing flammable liquids.
Typical state standards for permits include the submission of
the following information by owners of tanks: a description of
construction plans; a list of substances to be stored; a
description of the monitoring program; and names and addresses of
owners and operators. Some state regulations, such as those in
Kansas, include requirements for: the submission of information
on the location of leak detector connections to monitor any loss
of product from the piping or dispenser; the type of impervious
material to be used on the bottom of the excavation; and a
description of the natural soil or bedrock conditions in the
immediate vicinity.
Equipment Requirements. The NFPA recommends that tanks be of
sound engineering design and built in accordance with recognized
standards of design, such as Underwriters' Laboratories, the
American Petroleum Institute, and the American Society for
Testing and Materials. If corrosion is anticipated beyond that
provided for in design formulas, additional metal thickness or
suitable protective coatings must be provided. Requirements for
corrosion protection are provided in the NFPA standards for
flammable and combustible liquids (NFPA Code 30).
Tank Installation Requirements. The NFPA recommends that:
steel underground tanks be set on firm foundations and surrounded
with at least six inches of noncorrosive inert material; steel
underground storage tanks be covered with a minimum of two feet
of earth, or be covered with at least one foot of earth and
covered with a slab of reinforced concrete that is at least four
inches thick; and nonmetallic underground storage tanks have the
same burial depth requirements and should be installed in
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accordance with the manufacturer's•instruct ions. Several state
regulations require that tanks be anchored where the tanks are in
areas of high yroundwater or where a portion of the tank would be
submerged at maximum flood stage.
Secondary Containment Requirements. There are no NFPA
recommendations for secondary containment. Few states have
requirements for secondary containment. In those states that do
have secondary containment requirements, liners, double-walled
tanks, vaults, or other devices are generally used to prevent
leaked material from contaminating groundwater.
Replacement' Requirements. There are no NFPA recommendations
for the replacement of existing tanks, but the Uniform Fire Code
does call for- the immediate removal of leaking tanks from
service. Reinstallation is permitted after repair. Few states
have promulgated final regulations with tank replacement
requirements. However, Florida has issued regulations for a
phased approach to bring all existing underground storage tanks
into compliance with new tank requirements.
Inventory Review Requirements. NFPA recommendations for
inventory review include a provision that accurate inventory
records must be maintained on all flammable and combustible
(Class I) liquid storage tanks for indication of possible leakage
from underground storage tanks or associated piping. Typical
state regulations, such as the Ohio regulation, require daily
dipstick readings and record reconciliation, and weekly dipstick
tests for water content in the tank.
Testing Requirements. NFPA recommends that all underground
storage tanks, whether shop-built or field-erected, must be
tested before being placed in service in accordance with the
applicable sections of the code under which they were built. The
ASME code stamp, API monogram, or the listing mark of
Underwriters Laboratories, Inc. on a tank is evidence of
compliance with the test.
Typical state standards require testing only for tanks with
indicated product losses. Maryland requires tightness tests fo,r
all systems: where a product loss is indicated or suspected; the
-46-
-------
tanks are more than 10 years old or tanks are of unknown age;
prior to a change of ownership; and upon completion of
installation and prior to operation.
Monitoring Requirements. The NFPA recommends that, instead
of maintaining an inventory record, a leak identification program
be provided on all flammable and combustible (Class I) liquid
storage tanks for monitoring leakage from tanks or associated
piping. Several states require monitoring in addition to that
recommended by the NFPA. For example, the Kansas regulations
require that leak detectors be installed on ail new storage
systems where underground pressure piping exists between the pump
and a dispenser. Tanks located on farms with less than 50 feet
of delivery pipe are exempt from this requirement. Piping
monitoring systems must be located to provide access for
inspect ion.
Recordkeep ing Requirements. The NFPA recommends that
accurate inventory records or a leak detection program must be
maintained on all flammable and combustible (Class I) liquid
storage tanks for indications of possible leakage from the tanks
or associated piping. Most state regulations require that
records of daily inventory measurements be maintained at the
facility for a period of at least one year and be made available
upon request to representatives of the state and local agencies
upon request.
The number of states and localities that are taking action to
regulate underground storage tanks is growing rapidly. It is
very important that owners and operators be aware of all state
and local regulations that apply to their tanks and piping. For
information on these regulations, owners and operators should
contact the state or local office of environmental protection or
office of natural resources. The local fire marshal can also
provide details concerning local fire ordinances that deal with
underground motor fuel storage tanks.
-47-
-------
INSURANCE
As described in the Chemical Advisory and in the introduction
to this booklet, leaks of motor fuel from underground storage
tanks can cause damage to nearby property and contaminate
drinking water supplies. The tank owner or operator may be held
responsible for these situations, which can be extremely
expensive to correct and clean up. Therefore, tank owners and
operators should consider obtaining insurance that covers such
potentially large liabilities. Rhode Island has enacted
legislation that requires owners or operators of petroleum
storage tanks to purchase liability insurance to protect against
risks fron underground, as well as above-ground, tank leaks.
Other states are considering such requirements.
Many" firms with underground storage tanks, including
commercial gasoline stations, have comprehensive general
liability (CGL) policies. These policies cover pollution claims
resulting from "sudden and accidental" occurrences, but typically
contain a "pollution exclusion" clause which excludes "non-
sudden" pollution losses from coverage. Gradual leaks from
underground motor fuel storage tanks and piping may not be
covered under the firm's insurance policies.
A number of insurance companies offer an addition to a firm's
existing CGL policy to cover gradual pollution, including tank
leaks. The Pollution Liability Insurance Association (PLIA)
consists of 49 insurance companies which offer policies that will
cover gradual pollution. Information about PLIA may be obtained
by calling them at (312) 467-4034.
Another type of pollution insurance is a separate
environmental impairment liability policy. Currently, there are
less than 10 companies that will write an environmental
impairment liability policy. These policies generally are
written to cover only gradual pollution incidents.
Finally, several specific underground storage tank leak
insurance policies have been offered to petroleum marketers
-48-
-------
through state petroleum marketing trade associations. Specific
coverage of these pollution policies vary and should be discussed
with the broker.
Premiums, deductibles, and limits of liability vary greatly,
and may depend on an assessment of the probability that the
applicant's tanks will leak, including an examination of factors
such as the age, construction, and location of the tank. Also,
an applicant may be required to demonstrate that the firm's tanks
are not leaking.
-49-
AWBERC LltJKARY U.S. £PA
-------
HELPFUL REFERENCES
PUBLICATIONS
Groundwater: Information Pamphlet, Department of Public
Affairs, American Chemical Society, 1983. For copies, phone
(202) 872-8725 or write the Office of Federal Regulatory
Programs, ACS Department of Public Affairs, 1155 16th Street NW,
Washington, DC 20036.
Ground-Water Protection Strategy, US-EPA, Office of Ground-
Water Protection, August 1984.
Technology for the Storage of Hazardous Liquids; A State-of-
the-Art Review, New York State Department of Environmental
Conservation, January 1983. This manual is available by calling
(518) 457-4351 or writing the Bureau of Water Resources, New York
State Department of Environmental Conservation, 50 Wolf Road,
Albany, New York 12233.
The following publications have been prepared by the American
Petroleum Institute (API). They are available by calling API at
(202) 682-8375 or by writing API at 1220 L Street NW, Washington,
DC 20005.
Cathodic Protection of Underground Petroleum Storage Tanks
and Piping Systems, Publication 1632, 1983.
Installation of Underground Petroleum Storage Systems,
Puolication 1615, 1979.
Manual of Petroleum Measurement Standards. Chapter 6--
Metering Assemblies, Section 3—Service Station Dispensing
Metering Systems, 1983.
-50-
-------
Recommended Practice for Abandonment or Removal of Used
Underground Service Station Tanks, API Bulletin 1604, 1981.
Recommended Practice for Bulk Liquid Stock Control at Retail
Outlets, Publication 1621, 1977.
Recommended Practice for the Interior Lining of Existing
Steel Underground Storage Tanks, Publication 1631, 1983.
Recommended Practice for Underground Petroleum Product
Storage Systems at Marketing and Distribution Facilities, API
Recommended Practice 1635, 1984.
Standard Method for Measurement and Calibration of Horizontal
Tanks, API Standard 2551, 1965.
Underground Spill Cleanup Manual, Publication 1628, 1980.
TELEPHONE CONTACTS
For questions not answered by this booklet, call EPA toll-
free at (800) 424-9346, or in the Washington, D.C. at 382-3000
For EPA fact sheets describing the sources of financing
pollution control loans, call EPA's toll-free Small Business
Hotline at (300) 368-5888.
To report releases of oil reaching navigable water and
causing a sheen, call the National Response Center at
(800) 424-8802.
For information about insurance, contact the Pollution
Liability Insurance Association (PLIA) at (312) 467-4034.
-51-
-------
APPENDIX A: INVENTORY REVIEW FOR TANKS WITH
METERED DISPENSING PUMPS
-------
INVENTORY REV I » SHEET FOR TANKS WITH METERED DISPENSING PUMPS
TANK NO.
PART A
DISPENSING METER NO(S>.
OR, TANK SYSTEM NO(S).
IF MAN IFOLDED TANKS,
PROVING CAN _
METER CHEW
Dipstick Inventory
Column 1
Oar*
Column 2
Opening
Olp§tlck
Inventory
(oal Ions)
Co luntn 3
Deliveries
(In oal Ions)
Column 4
Total
[Column 21
plus
[Column 31
Column S
Closing
Dipstick
Inventory
(Inches)
Column 6
Closing
Olpstlck
Inventory
(oal Ions)
Column 7
Gone from
Tank
[Column 41
ml nus
[Column 61
Column 8
Meter Sales*
(gal Ions)
(from meter
sheet)
Column 9
Column 8 less
than (-) or
greater than
( + ) Co 1 umn 7
Column 10
Columns 7 i
8: Subtract
SiBl ler from
Laroer
I
ransferred 'rom Line I of Dispenser MsTer Recoralng Sheet.
T 3
I. MLMBER OF MINUSES (-) IN COLLMN 9, SART »
2. CUMULATIVE NUMBER OF MINUSES RECORDED FOR DEVIOUS 30-OAr =ERIOD(S). COPY -ROM LINE 3,
=ART 3 OF ''RECEDING 30-DAY SHEET, DR ENTER ;ERO iO) IF CURRENTL" "HE =ISST =ERIOO . . .
3. ADD LINES I AND 2
4. ACTION NUMBER FROM TABLE FOR TANKS «l TH METERED DISPENSING =LMPS
5. IS LINE 3 GREATER THAN LINE 4? | j YES | | NO
IF "YES", CONCLUDE THAT DAILY INVENTORIES ARE SHORT. IF "NO", CONTINUE ItTH INVENTORY TO COMPLETE i-fEAR EVALUATION.
-------
attraction* for Collating the> Inventory
Review Sheet
Part Ai "to bet completed «*ch day; preferably at about the saae
tlMr i.e., before closing or opening every day. Dipstick and
nets* readings nost be taken together while puap(a) is (are)
closed*
Write in the columns, as numbered:
1. The date.
2. The opening dipstick inventory in gallons. This number is the
previous day's closing dipstick inventory in Column 6.
3. The day's deliveries (in gallons).
4. The sum of Column 2 plus Column 3 ~ the total of fuel in tank.
5. The closing dipstick reading in inches.
6. The closing dipstick reading converted to gallons from tank chart.
7. Gone from tank -- gallons of fuel leaving the tank since last
dipstick inventory.
8. The day's sales (in gallons).
9,10. If Column 8 is less than Column 7, enter a minus (-) in
Column 9 to show that the closing dipstick inventory is "short"
(shows an underage) compared to deliveries and sales. Also,
subtract Column 8 from Column 7 and enter the difference in Column
10.
9,10. If Column 8 is larger than Column 7, enter a plus (+)
in Column 9 to show that the closing dipstick inventory is "over"
(shows an overage)- Also, subtract Column 7 from Column 8, and
enter the difference in Column 10.
9,10. If Column 8 is equal to Column 7, enter a zero (0) in
Column 9 to show that the closing dips.tick inventory is neither
over or short. Place a zero (0) in Column 10.
Part B; To«be completed at the end of each 30-business-day
period.
Step 1. Count the total number of minuses (-) in Column 9 of
Part A and enter on line 1.
2. On Line 2, write the cumulative number of short daily inventories
that occurred during the previous 30-day period(s) (this is the
number in line 3, Part B of the previous 30-day inventory sheet).
3. Add lines 1 and 2 and enter the total on line 3.
4. EUter on line 4 the critical value shown in Table 1 for the current
30-day period.
5. Compare lines 3 and 4. If line 3 is greater than line 4, a
continuing daily loss is presumed to exist.
-------
MANIFOLDED TANK SYSTEM RECORDING SHEET
(Sheet 1 of 8)
Manifolded Tank System I.D. Number
Type of Fuel
Day
2
3
Date
Physical Inventory Measurements
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
Tank
# 1
Tank
* 2
I
Tank
# 3
_
I
Tank
# 4
J
Tank
# 5
I I
J
I I
Tank
# 6
j
I I
I I
I I
I |
Tank
# 7
I
I
Tank
# 8
I
|_
L
Line F*
Totals
\
\
\
\
\
\
\
\
I
fc_
[V
\
U A
u
t
\
~\
L_
*Transfer Line F totals to the correct Inventory Review Sheet for this Tank System.
-------
MANIFOLDED TANK SYSTEM RECORDING SHEET
(Sheet 2 of 8)
Manifolded Tank System I.D. Number
Type of Fuel
Day
5
5
7
g
Date
Physical Inventory Measurements
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
Tank
# 1
L_ _J
I
Tank
# 2
Tank
» 3
Tank
* 4
Tank
# 5
Tank
# 6
Tank
# 7
I J
I
Tank
ft 8
Line F*
Totals
\
\
\~
\
\
\
\
\
_\
\
\
\
\
\
I
\
\
\
V
\
*Transfer Line F totals to the correct Inventory Review Sheet for this Tank System.
-------
MANIFOLDED TANK SYSTEM RECORDING SHEET
(Sheet 3 of fl)
Day
Date
Manifolded Tank System I.D. Number
Physical Inventory Measurements
Tank
# 1
Tank
# 2
Type of Fuel
Tank
# 3
Tank
t 4
Tank
# 5
Tank
# 6
Tank
# 7
Tank
# 8
Line F*
Totals
9
10
1 1
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A-t-B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
L- .
I
L 1
L 1
L I
l_ J
L 1
L 1
, I
1
I |
1 1
1 1
1 I
1 I
I
_j
J
1 |
1 |
|
1
J
j
1
1 i
I J
I j
1 I
k
\
\
\
\
\
\
\
\
K
fvL
L AZ
L V
*Transfer Line F totals to the correct Inventory Review Sheet for this Tank System.
-------
MANIFOLDED TANK SYSTEM FUEL MEASUREMENTS
(Sheet 4 of ft)
Manifolded Tank System I.D. Number
Type of Fuel
Day
1 3
1 4
1 5
16
Date
Physical Inventory Measurements
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
Tank
# 1
| (
| (
| |
I I
I |
1
J
_|
I
Tank
# 2
| (
1
I
I
Tank
# 3
._.
Tank
# 4
1 J
| (
L J
j
I _,
I
Tank
ft 5
Tank
ft 6
'
Tank
ft 7
, |
| (
Tank
# 8
|
| (
| I
Line F*
Totals
\
\
\
\
\
k
\
\
\
1
it
l\_
\
i
K_
\r
\
\
l \
i
*Transfer Line F totals to the correct Inventory Review Sheet for this Tank System.
-------
MANIFOLDED TANK SYSTEM RECORDING SHEET
(Sheet 5 of 8)
Manifolded Tank System I.D. Number
Type of Fuel
-1
Day
18
1 9
20
Date
Physical Inventory Measurements
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
Tank
# 1
I J
I I
Tank
# 2
Tank
* 3
Tank
* 4
Tank
* 5
Tank
f 6
Tank
# 7
Tank
# 8
Line F*
Totals
\
\
\
\
\
\
\
\
\
K
\
\
\
I \
N
\
\
\
•Transfer Line F totals to the correct Inventory Review Sheet for this Tank System.
-------
MANIFOLDED TANK SYSTEM RECORDING SHEET
(Sheet 6 of 8)
Manifolded Tank System I.D. Number
Type of Fuel
Day
21
22
23
24
Date
Physical Inventory Measurements
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B, Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
Tank
* 1
L
1 I
Tank
# 2
|
1 1
L J
Tank
# 3
I
Tank
# 4
Tank
* 5
Tank
# 6
L_
Tank
# 7
Tank
# 8
Line F*
Totals
\
\
\
\
\
1
\
LV
1 \
ul\
\
k
tx
x_
i V
I _A
L
l\
\
L\-
L X
l_ZX
*Transfer Line F totals to the correct Inventory Review Sheet for this Tank System.
-------
MANIFOLDED TANK SYSTEM RECORDING SHEET
(Sheet 7 of 8)
Manifolded Tank System I.D. Number
Type of Fuel
Day
TC
26
27
Date
Physical Inventory Measurements
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
Tank
# 1
Tank
# 2
Tank
# 3
Tank
# 4
Tank
# 5
| |
Tank
# 6
I
|
I
|
Tank
# 7
I
Tank Line F*
# 8 Totals
\
I \
I \
u__L\
L__J\__
|\
\
\
) \
I
iJHV
. i_V
I L_Y—
i \
i \
i
L
i \
\
j .
•Transfer Line F totals to the correct Inventory Review Sheet for this Tank System.
-------
MANIFOLDED TANK SYSTEM RECORDING SHEET
(Sheet 8 of 8)
Day
Date
Manifolded Tank System I.D. Number
Physical Inventory Measurements
Tank
# 1
Type of Fuel
Tank
# 2
Tank
# 3
Tank
# 4
Tank
ft 5
Tank
# 6
Tank
# 7
Tank
# 8
Line F*
Totals
29
30
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
A. Opening stick (gals.) (Yesterday's line E)
B. Deliveries (gals.)
C. Total of fuel in tank (A+B)
D. Closing stick (inches)
E. Closing stick (gals.)
F. Fuel gone from tank (gals.) (C-E)
I
V
\
\
\
\
k
\
\
L— V
\
"Transfer Line F totals to the correct Inventory Review Sheet for this Tank System.
-------
DISPENSING METER RECORDING SHEET
[FOR TANKS WITH MKTEREI) DISPENSING PUMPS]
Ta nk No . ;
or, if manifolded tanks, tank system no.
(Sheet 1 of 5)
Type of fuel
Day
1
2
3
4
5
6
Date
Meter Recordings in Gallons
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
Meter
#1
L J
Meter
tt2
|
L _J
L J
L J
L
L _J
L
Meter Meter
#3 #4
I
I
|
L J ,
1
i
1 I J
1
I
1
1
L J. _.
1 J__ _
1
!
I
1
Meter
#5
| |
Meter
#6
.
Meter
#7
I 1
Meter
#8
Line I*
Totals
x^
IX
X
X
/
x
x
x
x^
X
/
X
* Transfer Line I totals to Column 8 of Inventory Review Sheet
-------
DISPENSING METER RECORDING SHEET
[FOR TANKS WITH METERED DISPENSING PUMPS]
Ta nk No . ;
or, if manifolded tanks, tank system no.
(Sheet 2 of 5)
Type of fuel
Day
7
8
9
10
1 1
12
Date
Meter Recordings in Gallons
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
Meter
#1
I I
Meter
#2
Meter
#3
I I
Meter
»4
Meter
#5
Meter
#6
Meter
#7
Meter
#8
!
Line I*
Totals
^
\^
//
X
X
X
/
X
I X
X
I X
IX
I •
* Transfer Line T totals to Column 8 of Inventory Review Sheet
-------
DISPENSING METER RECORDING SHEET
[FOR TANKS WITH MISTERED DISPENSING PUMPS]
Tank No. ;
or, if manifolded tanks, tank system no.
(Sheet 3 of 5)
Type of fuel
Day
13
14
15
16
17
18
Date
Meter Recordings in Gallons
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
Meter 1 Meter
#1 I #2
I
|
f
|
I
I
I
J
I
|
f
I
|
I
I
I.
I
I
Meter
#3
Meter
#4
I
Meter
#5
Meter
#6
[Meter
#7
Meter
#8
Line I*
Totals
X
X
/
X
/
|X
/
X
X
X
X
X
* Transfer Line I totals to Column 8 of Inventory Review Sheet
-------
DISPENSING METER RECORDING SHEET
[FOR TANKS WITH METERED DISPENSING PUMPS]
Tank No. ;
or, if manifolded tanks, tank system no.
(Sheet 4 of 5)
Type of fuel
Day
19
20
21
1
22
23
1
24
Date
|
I
|
| j
!
i
Meter Recordings ' in Gallons
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-W)
G. Today's Closing Meter
M. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
Meter
#1
I 1
Meter
#2
|
|
Meter
#3
1 I
Meter
#4
t
1
|
1
!
I
1
Meter
#5
'
1
Meter
#6
|
|
Meter
#7
1
Meter
#8
,
|
Line I*
Totals
X'
IX
1
//
IX
1 X
v"
1
/
iX
1
X
X
1 X
IX
* Transfer Line I totals to Column 8 of Inventory Review Sheet
-------
DISPENSING METER RECORDING SHEET
[FOR TANKS WITH MISTERED DISPENSING PUMPS]
Tank No. ;
or, if manifolded tanks, tank system no.
(Sheet 5 of 5)
Type of fuel
Day
25
26
27
28
29
30
Date
Meter Recordings in Ga Lions
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
H. Yesterday's Closing Meter
I. Gallons dispensed (G-H)
G. Today's Closing Meter
JH. Yesterday's Closing Meter
jl. Gallons dispensed (G-H)
JG. Today's Closing Meter
JH. Yesterday's Closing Meter
I I. Gallons dispensed (G-H)
Meter
#1
Meter
#2
( |
-... — - i
Meter
#3
| I
[ J
|
( |
| |
Meter
#4
Meter
»5
I |
Meter
#6
Meter
#7
i
Meter
#8
Line I*
Totals
! .X
I/
/x
IX
/
^~
/
i/
/
/
\ /
X
Transfer Line I totals to Column R of Inventory Review Sheet
-------
APPENDIX B: INVENTORY REVIEW FOR TANKS WITHOUT
METERED DISPENSING PUMPS
-------
INVENTORY REVIEW CHART FOR TANKS WITHOUT METERED DISPENSING PUMPS
DIPSTICK READING
WITHDRAWAL OR FILL
Number
Start
1
Date
2
3
4
( INCHES)
Before After
XX
I
5
6
(GALLONS)
Before After
XX
I
1 \
o
Q
LOSS BETWEEN TOTAL ACTION IS THERE
WITHDRAWALS1 LOSS NUMBER2 A LEAK?3
XX
1
I
I I
I I I
10
1 1
1 2
I
I
I I
L 1 1
1
1 1
XX
XX
Yes
XX
No
XX
Gallons after last withdrawal or fill minus yalions before this withdrawal or fill.
2From Action Number Table for Tanks without metered pumps.
3There is a leak if the total loss for the qiven number of withdrawals and fills is greater than the action number.
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