No. KT-88-007(R)
       EVALUATION  OF U-TUBE
UNDERGROUND TANK  SYSTEMS
      FOR SOIL VAPOR TESTING

        Suffolk  County,  New York
              Revised March  1988

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                                   ,V..:Rep6rt No.  KT-88-007(R)
                   REPORT
          EVALUATION OF U-TUBE
UNDERGROUND TANK MONITORING SYSTEMS
          FOR SOIL VAPOR TESTING
           Suffolk  County, New York
              Revised March 1988
                  Submitted to:
            Midwest Research Institute
               5201 Leesburg Pike
                    Suite 209
             Falls Church, Virginia
                     22041
                      By:

                  Kaman Tempo
                 816 State Street
             Santa Barbara, California
                     93101
                  (805)963-6479

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Section
                               TABLE OF CONTENTS
   1      INTRODUCTION
    4       CONCLUSIONS AND  RECOMMENDATIONS
 APPENDICES
   2      INVESTIGATIVE METHODS ......... . ...................     2'1

          2.1  Description of Sites .........................     2-1
          2.2  Testing Methods .................. ......  .....     z'3


   3      RESULTS  ...... ". ...........................  ........     3"1

          3.1  Discussion of Total Concentration .......... ..     3-1
          3.2  Variation  in Chemical Composition ............     3-6
           4.1   Background  Concentration ......................      4-1
           4.2   Methodology ..................................      4"2
           4.3   Construction Design  and
                Installation Quality .........................      4-<*
     A     Calculation of Relative Detector Sensitivities
           for Isobutylene, Benzene, Toluene and Xylene .......      A-l

     B     Calculations of Concentrations from Photovac
           10S30 Peak Areas ...................................      B~1

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','"..        '                      LIST Of,  FIGURES    ,   :...;;.:| -..:: ":':'::

 Figure                          ""'"*        ^                        :   ^i

  1-1      Schematic Diagram of U-Tube Monitoring  System
           for Underground Storage Tanks	     1-2
  1-2      Location Map of Underground  Storage  Tank Sites .	...     1-4

  3-1      Pumping Time Versus Concentration  Plots for
           Known or Suspected Leak Sites	     3'3

  3-2      Pumping Time Versus Concentration  Plots for Non-Leak
           Non-Leak Sites with Moderate Soil-Gas

3-3
3-4
3-5
3-6
3 7
o /
3-8
3-9

Pumping Time Versus Concentration Plots for Non-Leak
Qi+nc un-nh i nw 9ni1-fia^ Rarkaround Concentrations 	
Scattergrams Comparing Performance of Photovac
Depth to Groundwater and Soil-Gas Concentration
Site Age Versus Soil -Gas Background Concentration

Variation in Soil-Gas Chroma tog raphic Signatures
Variation in Soil-Gas Chromatographic Signatures
at Non-Leak Si tes 	 , 	
3-4
3-5
3-7
3-8
3-9
3-10
3-12
3-13

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'/.;;.-   ,.  :  \                     LIST OH TABLES       : ...^:* =.--   :   :;

 Table                                                                  Page
  2-1     Summary of Site Characteristics  	        2-2
  2-2     U-Tube Characteristics and Test  Parameters	        2-4
  3-1     Summary of Background Concentration in U-Tubes  	        3-2
  4-1     Isolated Sites Show the Lowest Background
          Concentrations 	        4-3

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                                    SECTION 1
                                  INTRODUCTION
     This report is a summary and evaluation of the methodology and results of
background  soil  vapor  concentrations  measured  in  underground  storage  tank
(LIST) U-tube vapor monitoring devices.   Kaman Tempo performed this  study under
subcontract to  Midwest Research Institute  as a contribution  to the  EPA  UST
Federal Guidelines and Regulations.

     The study was conducted in'Suffolk County, New York, where a large number
of UST  sites  with U-tubes  have  been installed under  tight  County regulatory
control.   The County  regulation  most  relevant  to this  study  is the  tank
registration  program  which  provides an identification  number,  historical  use
data, and construction records for each tank.

     U-tubes,  originally  intended  for  leak detection  by  liquid interception
rather  than vapor monitoring, have  been  installed beneath  hundreds  of UST's
since  1980.  A schematic U-tube  construction diagram  is  presented in Figure
1-1.   The  U-tubes consist of  an  inclined PVC pipe with  perforations  only in
the  upper  half placed lengthwise  beneath the tank.  The  up-slope  end of the
perforated  pipe  is connected  by  a 90 elbow to  a vertical  riser  pipe.   The
lower  end  is  connected  by  a  tee  to a  sump  and  riser pipe.   All  parts  are
generally  of  Schedule 40 4-inch  PVC.   Risers are  generally  10  feet long and
inclined sections  average 25 feet  in length.

     The dual  purpose  of the study was to develop  a method for soil background
measurements  using U-tubes  and to collect a  background concentration  database
for  the study area.   In developing  the  testing method, the usefulness, style
and  quality  of  U-tube  installations  were  also   evaluated.   The motivating
objective  for the  soil  vapor concentration  background  database is the regu-
latory need  to  assign  a  threshold concentration alarm  level  for  automatic
vapor  monitoring  systems  and periodic manual  monitoring programs.
                                        1-1

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            Sump Riser    Elbow Riser
fal
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''''  All  the  sites  were  selected  direttly from the tanfcRegistry with the aid
of  additional  information provided  by  Cdunty Health  Department 'official s.
Several  site  criteria  were considered in the selection process.   For  logistic
reasons  all  sites  were  selected  within  a  five mile  radius.   An attempt was
made  to  select sites  with  a  variety  of  tank  products,  tank  construction
materials,  site  leak  histories,  depth-to-groundwater,  and site  ages.  The
selected  locations  are presented  in Figure  1-2.

     Kaman Tempo would like to  thank  Mr.  James  Pirn  and staff of Suffolk  County
Department  of  Health  Services,  Bureau  of  Hazardous  Materials,  for   their
cooperation and assistance in conducting  this  study.
                                        1-3

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              Sunken Meadow Pkwy


Northern State Pkwy
                          Approximate  Seal*  In  Mllaa
             #8265
   EXPLANATION

Location of underground Storage Tank Site
Showing Identification Number
          Figure 1-2.  Location  Map of Underground Storage  Tank Sites.
                                        1-4

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                                    SECTION 2
                              ilWESTIGATIVEf* METHODS
2.1  DESCRIPTION OF SITES
     Twenty U-tubes  at  nine sites were  visited during the  week of July  20,
1987.  The characteristics of each site  and  tank  are  summarized  in  Table 2-1.
Each U-tube and corresponding underground tank is  identified in the  table by a
Suffolk County tank tax identification number followed by a number designating
the  chronological  order of  testing  at  a  particular  site.   The three  sites
having a suspected  or  known history of  leaks  (5036,  8020  and  8037) according
to  Suffolk  County  officials   are  designated  by  bold  face  identification
numbers.

     All the  tanks tested contained  petroleum fuel  products  including  gaso-
line,  diesel,  and  kerosene  as  well  as  heating,  lubrication, and  waste oil.
Diesel  was the  only product  believed  to  have  leaked  from  visited  on-site
tanks; however, measurements were made at Site 8043 of trichloroethylene (TCE)
from a  groundwater  contamination  plume having an  off-site source according to
Suffolk County  officials.   Groundwater concentrations of TCE  in  the area are
reportedly on the order of several thousand micrograms per liter (ppb).

     Groundwater  depths  ranged from  27  to  161 feet  below  ground  surface and
are  bimodally distributed between levels shallower and deeper  than  50 feet.

     Based upon the number of years  that underground storage tanks have been
present,  the sites ranged  from  7 to 75 years  in  age.   Because  the  first
U-tubes  were installed  in  Suffolk County in 1980,  the  tanks tested  were no
more than  7 years  of age.  Tank types  were either fiberglass or  STIP-3 cathod-
ically protected.   No  plain  steel  or  buff-hide  tanks  were  available  for
testing.   Two of the sites were  greater than 600 feet distant from any  other
underground  storage tank, contained  only one  tank,  and  therefore  are  desig-
nated  as  "isolated" sites.
                                        2-1

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                                           Table 2-1.  Summary of  Site  Characteristics.
u-
Tube#
M\
' II 	
1079
5036-1*
5036-2*

8020-1*
8020-2*
8020-3*
8020-4*

8037-1*
8037-2*

8043-1


8052-1
8052-2

-
8265

Address

nppr nark A ClaremonttNE cort
Islip & Blacker(NW cor)


347 + Terry(NW cor)




25 +Terry(SE cor)


Crooked Hill+495+Vanderbilt+
Saatikos Pkwv
Commerce Dr+Adams Ave
Plymouth Blvd+25(NW cor)


Oser Ave+Pkwy Dr S Serv Rd
25A+Thompfinn Hill RdfNW cort
, Product
In Tank
(2]
SU
D
SU
R
D
U
U
SU
R
U
SU
R
D
R
D
U
SU
R
U
u

Products
on Site
G.W
G.D.K


G,D




G.H.W


G,D,H,L.W

D
G,H,W


U
G.D.W

Leaks
on Record
N
D/86


Suspected




Y


Offsite TCE
(51
N
N


N
N
Depth to
Ground-
water(3)
27.0
39.5


20.0




20.9


92.0

110.0
35.0


161.0
112.0
Depth to
Ground-
water^
shallow_
shallow


shallow




shallow


deep

deep
shallow


deep
deep
Site
Age
(vrsl
15
25


27




28


7

7
15


7
75
Date
Old tanks
Installed
1972
1962


1960




1959


1980

1980
1972


1980
1912
Date
New Tanks
Installed
1981
1983


1984




1984


1980

1980
1981


1980
1985

Tank
Type
Fiber
Fiber
Fiber
Fiber
Fiber
Fiber
Fiber
Fiber
Fiber
STIP 3
STIP 3
STIP 3
Fiber
Fiber
STIP 3
Fiber
Fiber

Fiber
STIP 3
Fiber

Isolated
Tank?
N
N "
N
N
N
N
N
N
N
N
;-,-; N
N
N
N
Y
N
N

 N
;.. Y
:. N
(1) Known or suspected leak sites denoted by asterisk
(2) Key: G=Gasoline
        R=Regular
        U=Unleaded
        SU=Super Unleaded
        D=Diesel
        K=Kerosene
        H=Heating Oil
        L=Lube Oil
        W=Waste Oil
(3) Depth to groundwater in feet below land surface.

(4) Groundwater deeper than 50 feet is designated as "deep".

(5) Suffolk County Officials report offsite release of
     trichloroethylene (TCE) to groundwater in vicinity
    of site 8043.

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"2.2   TESTING  METHODS                '.-**             ,,,^-'' -:-'' '    '  '"
      Background  total  hydrocarbon concentrations were measured  in  the  U-tubes
 by  three methods.   In  order of  performance these methods  include a  top-of-
 casing   measurement,   downhole  measurement,  and  time-domain   concentration
 measurement  while pumping  at  a high  discharge  rate.   The  primary analytical
 equipment  used was a Photovac Model 10S30 dual-column gas  chromatograph.   For
 comparative  evaluation  of  the  instruments  themselves,  a Photovac  TIP  and  HNu
 Model  PI-101 were also  used in each  method.   The chromatograph was not  used
 for  the  top  of casing measurement.

      The construction  characteristics of  the  U-tube  and  pumping times  and
 volumes  for  each U-tube are presented in Table  2-2.  The style  and quality of
 installations varied,  including  one  site  with water-flooded 2-inch  diameter
 steel  risers (#1072),  two uncapped risers and one  riser  (#8037-1 and  #8037-2)
 constructed  of perforated casing  (#8052-3).

 Downhole Background  Measurement Method
      The procedures  for  downhole measurement  of background soil vapor concen-
 trations in  U-tubes  developed during the study are detailed below.

 Field equipment  included the following:
      Mechanical  Packer (plumber's 4-inch wing-nut test plug)
      1-cfm vacuum pump
      1-liter tedlar sampling bag
      30-foot teflon 1/8" O.D. tubing
      Swagelok fittings to reduce pump intake to 1/8" O.D. tubing
      25-foot plumber's snake
      Photovac Model  10S30  gas chromatograph, Photovac Model TIP-I  and HNu
       Model  PI-101 photoionization detectors
      Calibrant gas (57 ppm  isobutylene and  200  ppb BTX)
      Centralizer
      Powerful flashlight
      Mirror
                                         2-3

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                                            Table 2-2.   U-Tube Characteristics
                                                          and  Test Parameters.
ro

u-
Tube#
m
1072
5036-1*
5036-2*
5036-3* '
8020-1*
8020-2*
8020-3*
8020-4*
8020-5*
8037-1*
8037-2*
8037-3*
8043-1
8043-2
8049
8052-1
8052-2
8052-3
8054
8265

UTube
Top Size
(inches)
2
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4


U Tube
Capped
Y
N
N
Y
Y
Y
Y
Y
Y
N
N
Y
Y
Y
Y
Y
Y
Y
Y
Y


Perforations
to Surface
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Y
N
N


U Tube
Flooded
Y
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N

Incline
Length
(ftt

20
20
20
21
32
16
32
32
18
18
18
0
0
20
26
26
26
16
25

Riser
Length

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Equipment Preparation:   i      . .:-    -;;-            ;; ...^y.^-~!
     The background measurements were made downhole through 1/8" tubing.  This
size  was  required  to  minimize the  interval  volume  and  concomitant flushing
times  between  sites.   To prevent the tubing  from  snarling inside the U-tube,
the  tubing  was  taped  to  the plumber's  snake  at  1  or 2  foot  intervals.  A
centralizer  was  attached  to  the  end of  the  snake 1  to  2 centimeters  above
the   tubing inlet.  The  purpose  of the central izer was to  lift the tubing
intake off  the bottom  of the U-tube where several millimeters of  condensation
were  frequently  encountered.

Testing Procedure:
      The  elbow and sump risers (Figure 1-2) were  visually identified with  the
aid  of  a  flashlight  or  mirror.    To  reduce  vapor   advection  and  resulting
dilution  by surface  air,  both  risers  were  never left  uncapped  at the  same
time.   The risers  were  also visually  inspected  for  flooded conditions.   The
top  of the sump  riser  was firmly  sealed  with a  mechanical  packer.  If  the
risers were not flooded, the snake was passed  down the  elbow riser to  the
mid-point of  the  inclined section  of the U-tube (usually 16 to  20  feet  above
snake  length).   The  tubing intake  was thus  positioned  directly  below  the
 center of "the tank.  For comparison,  measurements  were  also taken with  the
 intake positioned  at  the elbow at  sites 8020  (suspected leak  site)  and  8037
 (known leak  site).   The  riser opening  was immediately  recapped  to  prevent
 dilution by surface air.

      The pump's  intake and discharge ports were then connected to the 1/8-inch
 tubing and to a 1-liter tedlar gas sampling bag,  respectively.   The pump was
 not  able  to  discharge  at its rated  capacity due to the restriction  of the
 small  diameter  tubing.   When approximately i liter  of gas was  collected, the
 bag was disconnected  and  the pump was switched off.  The  bag was  then connect-
 ed alternately  to a calibrated TIP-I and HNu PI-101  and concentrations record-
 ed in ppm.  The bag and tubing were flushed with ambient air between measure-
 ments, testing  with the TIP-I for cross-contamination.
                                         2-5

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     Syrin'ge samples were taken from a^septum tee mounted!--upstream of the pump
intake and injected into the  10S30  chromatograph.   The  chromatograph was used
in the following configuration:

       flow rate - 10 milliliters per minute
       back-flush switching time at 50 seconds
     t  four-foot CSP-20M analytical column
       five minute analysis time

The detection limit for aromatic fuel components in this mode is approximately
1 ppm.   Injection volumes  were varied between  0.01 to  1.0 ml  depending  on
concentration indicated  by  the TIP.  To avoid overloading  the  10S30 detector
and column,  smaller  injections were used  when the  TIP  indicated  high concen-
trations.

     For five of the  seven  sites with multiple  U-tubes, as  many  U-tubes were
tested as  time  allowed.   After removing the  snake  from each elbow riser, the
riser  cap was  carefully replaced  to avoid  downhole contamination  or  vapor
dilution.

Time Domain  Background Measurement Method
     Immediately following  the  downhole  measurement,  the  1/8"  tubing  was
removed  and  disconnected  from  the  pump.   The  opposite  end  of  the   U-tube
remained  sealed.  The elbow riser was quickly fitted with a second  mechanical
packer having a i-inch hose-barb which was  connected to the 1 cfm pump by a
i-inch I.D.  Tygon vacuum hose.   A septum tee was  installed near to the test.
plug.  The entire U-tube-could be  pumped, thus  drawing soil gas  through  the
inclined   perforated  section,   while  periodic  samples  for  the   10S30 were
obtained  with a syringe from the septum tee.   The pump was briefly switched
off for each syringe  sample to avoid negative pressures  in  the  syringe barrel.

     The  pump discharge was continuously measured  with the TIP and  HNu.  The
flow  to  the TIP and HNu was  reduced  to an instrument-compatible  rate by means
of a  5-port manifold.  The  pumping rate was  monitored with  a Gilmont floating-
ball  type gauge.  Due to the U-tubes1  very  large diameter, the  pump was able
                                        2-6

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"to  pump without restriction at its rated  capacity  of  approximately 1 cfm (30
liters per minute).

Instrument Calibration Procedure
     The  10S30, TIP and HNu were calibrated to  a  57 ppm isobutylene standard
on  a  daily  basis.  All  concentrations  in  this   report  are  given  as  ppm
isobutylene.

      First,  the  instruments  were zeroed  with  ultra  pure  air  from the  same
cylinder  used for 10S30 carrier gas.   A tedlar gas  sample bag was  then  filled
with  isobutylene standard  gas.   The  TIP  and  HNu  were then alternately cali-
brated  to the isobutylene and rezeroed twice.   A check for syringe background
contamination was run for the 10S30 prior  to isobutylene  standardization.

      A 200  ppb  benzene/to!uene/xylene (BTX)  gas  standard  was  provided  by
 Suffolk  County  to  aid  the  interpretation  of chromatographic  fuel  product
 signatures.   The BTX  standard  was  also used  to calculate  the  10S30 detector
 sensitivity  for  isobutylene relative  to  benzene,  toluene  and xylenes.   The
 ratios of concentrations (sensitivity coefficients) reported  as isobutylene to
 concentrations of the actual compounds are listed below.

           Benzene   0.94
           Toluene   1.07
           Xylenes   0.36

 These values indicate that although benzene and toluene are reported within 6%
 of their  true  concentrations,  because  of  the   10530's  low  sensitivity  to
 xylene,  reported  concentrations  of  xylene  are   much  lower than  their  true
 values.  A true  xylene  value can be obtained  by dividing the reported  value by
 a  0.36  sensitivity coefficient.  Xylene  was  encountered  in  only a few of  the
 U-Tubes  in this  study  and  therefore this  problem was  insignificant.
                                         2-7

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                                    SECTION 3
                                     RESULTS
3.1  DISCUSSION OF TOTAL CONCENTRATION
     The total petroleum hydrocarbon concentration measured  in  20  U-tubes  are
summarized  in Table  3-1.    The  known  or  suspected  leak  sites,  denoted  by
asterisks,  clearly  show the highest  concentrations.   Concentrations  ranged
from below the detection limit to greater than 2200 ppm as isobutylene.

     The  complete pumping  concentration data  are presented  in  Appendix  B,
showing the  calculated  concentration  for each compound and  sum total  concen-
tration of all compounds detected.  The maximum value from Appendix B for each
U-tube appears in Table  3-1.   No TIP  data were available  for sites 1072, 5036
and 8265  because  of  low instrument battery conditions.   No  downhole  data  are
available  for site  1072 because of flooded  conditions  and the  inability to
identify the  elbow riser in the  2-inch diameter tubing.

     In  general,  the mid-point downhole  TIP reading  approximates the  TIP
pumping maximum reading; however, the  10S30 downhole readings are  generally 20
percent lower than the  10S30  pumping maximum  readings.

     Top-of-casing  readings prove to  be poor indicators  of true  soil   condi-
tions  as  they were greatly  influenced by wind conditions.  For example,  very
small  top-of-casing  readings  and very  large pumping and downhole readings  were
obtained  at U-tubes 5036-1  and  8020-1.   It is significant that both of these
U-tubes are at known leak  sites.

       The patterns of variation which concentration followed with time  during
pumping appear  to  be  dependent on the general  concentration  level  for  the
U-Tube being measured.  At high concentration values, the concentration level
 stabilizes somewhat  at approximately  10 minutes (approximately  3  times  the
 internal  volume of the U-tube)  (see  Figure 3-1).  For sites with  moderate and
 low concentrations, no  apparent  plateau  was  reached  after  30 minutes  of
 pumping (see Figure 3-2 and 3-3).
                                        3-1

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                                      Table 3-1.  Summary of  Background  Concentration
                                                    in U-Tubes.
u-
Tube#
	
1072 	
5036-1*
5036-2*
5036-3*
8020-1*
8020-2*
8020-3*
8020-4*
8020-5*
8037-1*
8037-2*
co 8037-3 .
1X5 8043-1(3)
8043-2(3}
8049
8052-1
8052-2
8052-3
8054
8265
10S30
Midpoint
iPPml 
f3\
- lgl .
373.00
645
4 no
1^3 	
758
730
513
365
fyAc
^40
11.9
6.8
0
31.09
0(4)
0
.
3.44
TIP
Midpoint
fnnm)
1HK"" .
-
1142
1237
840
424
pop

26
14.2
7.9
-
HNu
Midpoint
(ppm)

50
210
190
165
155
140

12.6
11.1
3.3
0
10S30
Elbow
(ppm)

-
547
599
445
222
10.8
OFFSCALE
OFFSCALE
_
-
-
TIP
Elbow
(ppm) ._

-
927
855
623
311
180
1274
1136
1050
-
-
-
HNu
Elbow
(ppm)

 ~
200
200
172
150
100
0
0
0
-
-
-
10S30
Max TIP Max HNu Max
(ppm)(5) (ppm) (ppm)
???
692
>2201
OFFSCALE
1180 1300 -.
-
17.7 15
1 1 .3 9.3
.3 l.b
67.4 56.7
80.3 35
0 2.7
0.52 1.6
5.88
112
142
49
150
-
14.2
8.7
4C
3
35
32
1.3
1,5
6.5
TIP Top
of Casing
(ppm)
-
-
84
130
270
14.5
140
1200
126
696
8.5
0
7 5
' J 	
6.5
2
6.6
0
-
HNU Top
of Casing
(ppm)
1
1
50
40
70
15
40
9.5
13.6
11
65
8
8.8
1
4
4
0
0
0
o
(1)  Known or suspected leak sites in boldface.
(2)  Blank spaces indicate measurement not taken.
(3)  Suffolk County officials report offsite release of TCE to groundwater in vicinity of site 8043.

     Concentrations measured in 4" PVC vapor wells.


(4)  Injection volume  too small = .02 ml.  Detection limit approximately 10 ppm.


(5)  Maximum readings for Photovac 10S30, Photovac TIP and HNu measured while pumping continuously at 1 cfm.

    See Appendix B for list of all concentrations measured during pumping.

-------
                                       e-e
                                                                CONCENTRATION IN PPM
  Id


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   <-l-

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   to
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   -S
CONCENTRATION IN PPM
                                                Concentration in ppm
c
1
"H. o "
3
g Time In Mil
i0'
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<



1 1   1 1 1
' "^




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GO 00 00
IM


i
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-------
                    CONCENTRATION IN PPM
  (D

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-" Z
rt- 3
3"U


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fD  \
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to 3
<-* fD
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-s o>
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 c -
 3 O
 O- 3

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 r+ -h
 -5 O
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    r~
    fD
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    co

    t-t-
    fD
    to
                                                                     CONCENTRATION IN PPM
CONCENTRATION IN PPM

  8          8    S
8
  CONCENTRATION IN PPM

-------
                                            S-E
                    CONCENTRATION IN PPM
   -s
   tt>

   CO
   i
   CO
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          m o
ill
(O (O       08

-------
"    At low  concentrations,  measurements  from  the three instruments  are  in   .
 fair agreement (see Figure 3-3).  However, the HNu did not  perform- linearally
 with the other instruments above approximately 50 ppm.   Figure  3-4 illustrates
 the  linear  agreement  of 10S30  and TIP  measurements and  the  non-linearity
 between the HNu data and with TIP data above the 50 ppm concentration level.

      A  correlation  is suggested  between  depth-to-groundwater and  concentra-
 tion.   Figure  3-5A shows the distribution of  groundwater  levels as well  as
 highest concentration  measured  at each site.  Note the  break  in distribution
 at  about  50 feet  below  land  surface.  Among  non-leak  sites, a  fairly  good
 correlation is observed  between total  concentration and depth-to-groundwater,
 with  concentration exponentially  decreasing with  depth-to-groundwater.   The
 fact  that  all  leak sites were located in  shallow  groundwater  areas is  purely
 coincidental, therefore  leak  sites  are not plotted in Figure 3-5B.

       The  time that a  site  has  been  in  service for  underground fuel  product
 storage (site  age) did not correlate with background soil  vapor  concentration
 as  well as  depth-to-groundwater (see Figure  3-6).   However,  if  the  75 year
 point  is  removed  from  the  dataset,  a  general  upward  direct correlation  is
 observed.   This trend may  be  ascribed to  such factors as  small  unreported
 overflows  during delivery and dispensing  which could  cause  a slow accumulation
  of product in the  soil.

       The distribution of soil-gas  concentration at sites  with  multiple  tanks
  and U-Tubes can help  identify leaking tanks.   For  example, a  leak was  suspec-
  ted  at Site 8020 where five tanks  (8020-1  through  8020-5)   have  been  placed
  side  by side  with their centers  spaced  ten feet  apart.   Concentration  drops
  steadily with distance  from  758 ppm at 8020-1 to 245 ppm at  8020-5.  A former
  or existing leak at 8020-1 is clearly indicated by this distribution, assuming
  that  concentration  does not continue to  increase  away  from  the tank cluster.
  A leak was verified at  this  site by the county.

  3.2   VARIATION  IN  CHEMICAL  COMPOSITION
        The  unique  chemical  compositions of  fuel products  are identifiable by
  their chromatographic  signatures  which  are  defined  by  characteristic  peak
  shapes, relative  peak areas, and retention  times  for each  chemical  component.

                                          3-6

-------
           Correlation of All TIP vs. All Photovac Data
          2000
                    T
                    200    400   600   800   1000  1200
                    Concentration Measured by 10S30     (ppm)
                   Correlation of HNu vs. TIP Data
                           100          200         300
                   Concentration Measured by HNU (ppm)

Figure 3-4.  Scattergrams comparing performance of Photovac
             10S30 TIP and HNu.

             a.  Note good linear fit of TIP and 10S30 data.
                 (Top-of-casing readings removed.)

             b.  Note exponential correlation of TIP and HNu data,
                 (Top-of-casing and outlying zero HNu readings
                 removed).
                                3-7

-------
       a)
                                                      (0.52)
                                            (5.88)
                                            (1.3)
                                         (17.7)
                               (>2200), Leak site
                             (80.3)
                            (222)
                            Offscale (1274 by TIP), Leak site
                           (1180), Leak site
                    0                  100                 200
                    Depth to Groundwater In Feet Below Land Surface
       b)
                 300-1
              E
              200-
            ,=
              s
*  1
3*
                 100
                            #1072
                                       ^9
                              \       \  #8265
                                  #8043j^\i
                                         #8054
                     0                  100                200
                     Depth to Groundwater in Feet Below Land Surface
Figure 3-5.   Depth to  Groundwater and Soil-Gas  Concentration
              at U-Tube Sites:
              a.  Depth to Groundwater for All Sites Showing Maximum
                  Soil-Gas Concentration Measured  by 10S30 in
                  Parentheses.
              b.  Depth to Groundwater Versus Soil-Gas Concentration
                  at  Non-Leak Sites.
                                     3-8

-------
o
o
u
    SITE AGE VS. CONENTRATION IN SOIL VAPOR

    3000
a.
Q.
5   2000 -
    1000-
               G
               B
                 20       40       60
                    SITE AGE IN YEARS
80
      Figure 3-6.  Site Age Versus Soil Gas Background
                 Concentration Scattergram.
                         3-9

-------
                       (0.6)
                       (0.9)
                   Benzene
                   Toluene
                                                                            (0.35)
tonrt-f HUH
MW.TSIS 
O*RT smo
ruDTTER otunr
IWM.TSIS TIPt
CTCLC Tine
  JUL.T
s
l  an/mn
ia.1 
STOP t
twiru RUN
IWOCTSIS 
cnotT srtio
fLOTTCK OtLIT
fittncTsis rinc
CTCLi TIBS
   JULT 33

 31
 t  r1/I1:n
 li.9 $
3M.( 
 a  K:n
   run
           33
A.   BTX Standard
                                    B.   Site:   8052
                                         Unleaded
                 (0.4)
      (0.6)
                                                              0.4)
                                                              0.55)
                                                              JULT 32 IS7
     Id*      JULY 21 1M7
 IWM.TSIC     10
 CIMIT SrCtO     1  .(VTOd
 run ten esukT  u. s..
 tywCTtje rut* aw.* 
 CTCLC rinc     a  A>*
                                     . KNXLTStS 
                                      OlIWT STUD
                                      PUITTCK DCUrr
                                      WM.TSIS TIHK
                                      CTO-I TIM
                                      TCHPOKITIM
            II.  !
            3M.* S..
               nm
 C.   Site:   1072
      Super  Unleaded
                                     D.   Site:   8052
                                          Regular
      Figure 3-7.
          Chromatograms of  fuel  products:   peak retention
          time in  minutes in parentheses.   Samples  B5 C,
          and D  obtained from fill pipes  of actual  fuel  tanks,
                                        3-10

-------
"-the  chromatpgraphic signatures  of the, soil-gas  samples.;--from  U-Tubes varied
 significantly  with site location, different  U-Tubes  within particular sites,
 and  pumping  time.

       Chromatograms  of vapor  samples  obtained from the  fill  pipes of under-
 ground storage tanks containing unleaded, super unleaded and regular  fuel  are
 compared  to  the signature of a benzene/toluene/xylene standard  in  Figure  3-7.
 Concentrations of benzene, toluene, and  xylene in the standard  (Chromatogram
 A)  are nearly equal,  however,  it appears by comparison with Chromatograms  B,
 C,  and D that -actual  fuel  products  contain  low  levels  of toluene and xylene
 relative  to benzene.   These  observations  are consistent  with previous  site
 work at refineries performed  by Kaman.

      Considerable variation in chemical  composition of soil-gas  is observable
 for the same  product  measured  at different pumping times  and  different  loca-
 tions in  soil-gas (see Figure  3-8).  The only product  known  to have  leaked at
 Site 8020 was  diesel, however, Chromatograms  E  and  F represent a noticeable
 variation in  samples  from the  same   U-tube  taken 10 minutes apart.   Three
 casing volumes  were  purged  during  this  period.   Note  the  increase in  peak
 height of the first peak with  increasing pumping time.   Chromatograms G  and H
 depict variations in relative peak heights at two separate diesel  spill  sites.

      Variations  in  the composition  of soil  gas  are also observed  in non-leak
 sites with very low background concentrations  (see Figure 3-9).  Chromatograms
 I and  J, obtained  beneath two different  tanks  at the  same  site  demonstrate
 differences  in  relative  concentrations (peak  heights)  of  the  same  three
 compounds.  Chromatogram K, representing a soil gas sample taken above a known
 TCE groundwater plume  with an  off-site source, depicts a second peak  shape  and
 retention time that contrasts  with the petroleum product background signatures
 of  Chromatograms I and  J.   TCE coelutes  with other compounds  in the second
 peak  causing  the  unusual peak  shape in Chromatogram K.
                                        3-11

-------
          -__   (0.3)
                (0.5)
                (0.6)
                                              SWBT	
                                                  (0.3)
                                                 . .(0.5)
                                                    (0.6)
.STOP t  258.7
WPPLC KUH
IWN.TSIS 
CMT SPUD
rUJTTEK OCLFT
CWN.TSIS Tine
CTCLC Tine
TEnPEMTUM
              JULY 24 lit?
            23
             1
               .twin
 E.   Site:   8020-1
                               .STOP *  3ee.a
                               WWPW MM
                               WM.YCIS *    24
                               CtW*T SPUD    1
                               PLOTTCK DUT  ! !
                               IWM.TSH Ttr M. s>*
                               CTCLE Ttnc       "'A
                                                          JULY 24 1M7
                                              F.   Site:   8020-1
  sr-
                            (O.A)
                            (0.6)
                                                (0.5)
                                                (0.6)
      *  .a?, i
      ; IBM      JULY 21 1917
       ;    at
  OMIT SPIED    i  n/nifi
  PUDTTIK Oturr  ! f
  r*w.Ysic Tine SM.I s*
  CTCLC Tine      nm
             33
  G.  Site:  5036
                                               STOP t
                                                      .
                                KHN.TSIS *
                                CHMIT SPEED
                                PLOTTfK DtUT
                                WW.YSIS Tine
                                CTCLC TIK
                                                           JULY 24 19*7
                                                         27
                                                          i  rvnm
                                                         ! Set
                                                          
                                                         57
                                                            dm
                                              H.   Site:   8020-2
Figure 3-8.
Variation in  Soil Gas  Chromatographic  signatures at
known or suspected  diesel   leak  sites:   Chromato-
grams  E  and  F  represent   samples  from  the  same
U-tubes  taken  ten  minutes  apart  during  pumping.
Three  casing  volumes   were   purged   during   this
period.   Note the  increase  in  relative peak  height
of  the first peak with pumping time.   Chromatograms
6  and H  depict variations  in relative peak  heights at
two separate spill  sites.
                                   3-12

-------
   SIIWT.
               = (0.3)
                 (0.5)
                (0.6)
                                             OHM.TSIS     9
                                             OWKT SMID    t
                                              WWLYSIE TIC* 3M.( G*
                                              CYCLE Tint     rt'n
                                              TOIPtWITUMC   39
   ?IOP S  213. 1
   SWTLE IBM
   KNM.TSIC 
   G#WT SPEED
   ruJTTtn oeLurr
   KHM.TSIS Tint
   CTCLC Tint
  JULT 32 IM7
                                J.  8052-1
17
 I
3M. St
   dm-
 39
                                    Note changes  in relative
                                    peak heights.
    I.  Site:   8052-2
                                             ., _  (0.4)

                                             (0.9)
                            5 TOP i  188.9
                            m.t n*i      JULT
                            MM.TSIS C    14
                            CXMIT snco    i  nxn
                            fUJTTE* OCUHr  ! 
                            WM.TSIS Tir* 3M.t St
                            CTCLC rine       nm
                                      a?
                            K.   Site:  8043-1
                                 Offsite TCE
Figure  3-9.   Variation  in Soil Gas  Chroma tographic Signatures  at
              non-leak  sites.   Chroma tog rams  I  and  J,  obtained
              beneath  two  different   tanks  at  the  same   site,
              demonstrate differences  in  relative  concentrations
              (peak   heights)   of  the  same  three  components.
              Chromatogram  K,  representing  a  soil  gas   sample
              taken  above a known TCE groundwater  plume with  an
              offsite  source  depicts  a peak shape  and  retention
              time   that   contrasts  with   the  petroleum product
              background signatures  of Chromatograms  I and  J.
                                  3-13

-------

-------
                                ,    SECTION 4        .-.*?.i
                         CONCLUSIONS AND RECOMMENDATIONS
4.1  BACKGROUND CONCENTRATION
     1.   Soil vapor concentrations at sites with  leak  histories  exceeded 122
          ppm.  However, measurements  for this study were  taken  months  after
          the  leaks  had occurred.   The   122  ppm  measurement was taken  in  a
          U-tube that was  approximately  50 feet distant from the location of
          the  former  leaking tank.  Measurements  taken closer to  tanks  with
          more  recent  kflown leak  histories  had off-scale  readings exceeding
          2000  ppm.  The concentrations  may  have been  on the order of 10,000
          ppm,  had  equipment capable of  such  measurements  been used.  There-
          fore,  Kaman  Tempo feels that  an alarm  level  much greater  than 500
          ppm may be acceptable for detecting  leaks as  they occur.  The actual
          alarm"level could  be set lower  for sites with lower background vapor
          concentrations.

      2.   Background  concentrations  appear to be  an order of magnitude higher
          in  areas  of shallow groundwater.

      3.   Background  concentrations are  often influenced  by  non-leak events
          and conditions,  e.g.  off-site  TCE  spill  that resulted in  a ground-
          water contaminant plume at Site 8043.

      4.   The chromatographic signatures of the soil-gas samples from U-Tubes
           varied significantly with  site location,  different  U-Tubes within
           particular sites, and pumping  time.  Therefore,  care should be used
           in  determining  which  tank at  a site is  leaking based  on chemical
           composition  alone.   Each tank should  be  monitored   separately and
           leaks identified on the basis of concentration level.

      5.   Older sites  (sites  that have  been  in service for .underground fuel
           storage for  many  years)  generally  have  higher background concentra-
           tions than do younger sites.
                                         4-1

-------
'""    6.   'Isolated  sites (sites .greater than 600 feet.:di.-starit from other tank
          sites)  had the  lowest background concentrations  of those measured
          (Table  4-1).   The alarm level could be. set at a lower  level at such
          sites than for non-isolated sites.

      7.   Background concentration  level  appears  to  be  independent of tank
          construction  material.

 4.2  METHODOLOGY
      1.   U-tubes can be used effectively to monitor the concentration  of fuel
           product components in  soil-gas  in  granular  underground storage tank
           backfill.

      2.    Elevated  concentrations measured  in  U-tubes  can indicate the occur-
           rence of  tank leaks.

      3.    The  most accurate   representative  background  concentrations  are
           obtained  by  pumping  a minimum  of  nine casing volumes  (30 minutes at
           1  cfm)  from the  U-tubes  (accuracy  is   based  on  stabilization of
           concentration with time).   However, this  method is  time  intensive.

      4.   Many  U-tubes can  rapidly  be  measured  in  one  day  by the downhole
           method    to   yield   concentrations   within  20    percent   of  the
           concentrations  measured by the  pumping method.  This accuracy should
           be  sufficient for  leak detection  purposes.

      5.   The top-of-casing  method does  not provide  reproducible  or represen-
           tative information  and  should not  be  used  in  a  formal  monitoring
           program.

      6.   Concentrations  measured   with  the  HNu  PID-101   do  not  correlate
            linearly with those measured by  the  Photovac  10S30 or TIP (based on
           comparison of data from a single instrument of each model).
                                         4-2

-------
Table  4-1.  Isolated sites  show the  lowest
             background concentrations.
u-
Tube#
m
1072
5036-1*
5036-2*
5036-3*
8020-1*
8020-2*
8020-3* '
8020-4*
8020-5*
8037-1*
8037-2*
8037-3*
8043-1
8043-2
8049
8052-1
8052-2
8052-3
8054
8265

Isolated
Tank?
N
N
N
N
N
 N
N
N
N
N
N
N
N
N
Y
N
N
N
Y
N
10S30
Midpoint
(ppm)
- (Z\
373.00
645
123
758
730
513
365
245
-
-
.
11.9
6.8
0
31.09
0(4)
0
0
3.44
TIP
Midpoint
(ppm)
.
-
-
.
1142
1237
840
424
222
-
-
-
26
14.2
7.9
-
-
.
.
-
 (1)  Known or suspected leak sites in boldface.


 (2)  Blank spaces indicate measurement not taken.
                         4-3

-------
4.3  CONSTRUCTION DESIGN AND INSTALLATION,QUALITY
     1.    Inconsistent  U-Tube  construction  design  and  installation  quality
           were  observed in this study  resulting  in erratic monitoring condi-
           tions.  Riser caps  must provide a good  atmospheric seal  and should
           be  installed sufficiently  below  grade  to  allow  clearance with the
           monument  lid.  Risers must  be constructed of  non-perforated casing.

     2.    Design  considerations  should include locking caps  and surface  seals
           to  prevent tampering  or  inadvertent  contamination  by  surface spills.

     3.    Smaller  diameter  pipe  and  elimination of  the  sump  riser   would
           obviate the  long  pumping  times  or  large  pumping  rates  needed for
           monitoring of 4-inch  casing.

      4.    Because high background concentrations  can persist in soil gas for
           longer than  two years  after a leak, e.g.  Site  5036, a  monitoring
           system cannot  function  properly  unless  all  contaminated  soil  is
           excavated before reinstalling tanks  at  a leak site.
                                         4-4

-------
                  APPENDIX A

CALCULATION OF RELATIVE DETECTOR SENSITIVITIES
 FOR ISOBUTYLENE, BENZENE, TOLUENE, AND XYLENE

-------

-------
  Apoendix A.   Calculation  of Relative Detector Sensitivities
                 for Isobutylene,  Benzene, Toluene and Xylene.
Date:  7/24/87
 Isobutylene STD Cone, (ppm) =     57
 Isobutylene STD inj. vol.(ml) =    0.02
       Isobutylene STO Gain      2
Isobutylene STD Area (sqmm) =     20
K= 0.114
   Where K = (STD Cone. *  STD inj volume *  STD Gain) / STD Area

   Cone, of Sample = (K * A)/ (V* G)
   Where A,V and G  are sample Area, Volume, and Gain, respectively.
                         Compound
                         Benzene
                         Toluene
                          Xylenes
Actual
Concentration
(DDirri
0.224
0.214
0.223
Injection
Volume
/mil
0.7
0.7
0.7
Gain
50
50
50
Peak
Elution Time
(min)
6
9
19.5
Peak
Area
(sqmml
65
70.5
25
Concentration
Computed as
	 Isobutylene
0.21
0.23
0.08
                     Relative sensitivity'
                            0.94
                            1.07
                            0.36
                            Compound       Note:
                            Benzene        Actual concentrations of BTX were 224,214, and 223 ppb.
                            Toluene        Benzene and toluene have early identical detector sensitivities as isobutylene.
                            Xylenes        Xylene detector sensitivity is much lower.
                        * (Concentration as isobutylene)/(Concentration as BTX)

-------

-------
          APPENDIX B

CALCULATIONS OF CONCENTRATIONS
FROM PHOTOVAC 10S30 PEAK AREAS

-------

-------
                                         Appendix B,.  Calculation of Concentrations from Photovac 10S30 Peak Areas.
                                                                                                                            Page 1
U-Tube    1072
Product   SU
   Date 7/21/87
Isobutylene STD Cone, (ppmj =
           STD inj. vol.(ml) =
                 STD Gain 
         STD Area (sqmm) =
                                     Concentration
INJ Vol
fmn
not run
1.00
1.00
0.02
0.02
0.02
:;'.' Peakl
But. t Area
-Gain (mini (samrrrt

71*
'2
2
2
2

4
3.5
3.5
3.5
3.5

189
384
34
40
41
    57
   0.02
    2
    24

Peak 2
  But. t
   (mini
0.095
Where K
. (STD Cone. * STD inj volume * STD Gain) / STD Area
                                                              Area
                                                                     Cone, of Sample . (K * A)/ (V*G)
                                                                     Where A,V and G are sample Area, Volume, and Gain, respectively.
                                                                                  Peak3
                                                                                   Elut. t    Area                       Total
                                       (sgmmi  concentration   (mhiL. JaammL  Concentration
                                              8.98
                                             18.24
                                             80.75
                                             95.00
                                             97.38
                                     6
                                     6
                                     6
                22
                28
                48
         0.00
         0.00
        52.25
        66.50
       114.00
          20
          20
          20
          20
 40
2.5
  5
4.5
0.00
1.90
5.94
11.88
10.69
  8.98
off scale
 138.94
 173.38
 222.06
Measuring
  Point/
 Elapsed
  Time
 midpoint
    0
    16
    21
    25
    29

-------
U-Tube 5036-1
Product D
Date 7/21/87
INJVol
(mu 
0.02
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
. ;2
2
2
2
2
2
2
2
Appendix B.. Calculation of Concentrations from Photov
Isobutylene STD Cone, (ppm) - 57 K- 0. ^
STD inj. vol.(ml) - 0.02 Where K = (STD Cone.
STD Gain - 2
STD Area (sqmm) = 29 cone. p
Peakl P"*2 PF^t3
Elut.t Area Elut. t Area Elut.t
(mini (sorting nnnrentration (mini isgmml. carOTntration. -imiDL.
4
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
3.5
55
17
68
71
50
32
30
47
42
51
108.10
33.41
133.66
139.55
196.55
125.79
117.93
184.76
165.10
200.48
5
5
5
5
5
5
5
5
5
5
35
7
27
61
24
17
17
18
15
22
68.79
13.76
53.07
119.90
94.34
66.83
66.83
70.76
58.97
86.48
6
6
6
6
6
6
6
6
6
6
ac 10S30
STD inj v
\)/ (V*G)
rniple Aree
Area
(sqmml _
100
38
80
120
102
96
72
52
65
99
Peak Areas.
olume * STD Gain) / STD Area
\, Volume, and Gain, respectively.
Total
rnncontratiort finncentratlon
196.55
74.69
157.24
235.86
400.97
377.38
283.03
204.41
255.52
389.17
373.45
121.86
343.97
495.31
691.86
570.00
467.79
459.93
479.59
676.14
Page 2
Measuring
Point/
Elapsed
Time
Midpoint
0
2
6
10
14
17
22
27
32

-------
U-Tube
Product
Date
INJ Vol
(ml)
0.01
0.02
0.02
0.01
0.005
5036-2
S
7/21/87

 -Gain
.'2
"'3
':?
2
2
Appendix B. , Calculation of Concentrations from Photovac 10S30 Peak Areas.
Isobutylene STD Cone, (ppm) - 57 K- 0.07862068
STD inj. vol.(ml) - 0.02 Where K  (STD Cone. * STD inj volume * STD Gain) / STD Area
STD Gain - 2
STD Area (sqmm) - 29 Cone, of Sample - (K * A)/ (V*G)
Where A,V and G are sample Area, Volume, and Gain, respectively.
Peak 1 Peak 2 Peak 3
Elut. t
(min)
4
4
4
4
*
Area
(sqmm)
52
50
46
50
280

Concentration
204.41
98.28
90.41
196.55
2201.38
Elut. t
(min)
6
6
6
6

Area
(sqmm)
112
105
175
50

Elut. t
Concentration (mini
440.28
206.38
343.97
196.55
0.00
Area
(sqmm) Concentration
0.00

0.00
0.00
0.00
Total
Concentration
644.69
304.66
434.38
393.10
2201.38
Pages 
Measuring
Point/
Elapsed
Time
midpoint
0
2
16
25
BOLDFACE TOTAL CONCENTRATIONS ARE APPROXIMATED FROM OFFSCALE PLOTS

-------



* *


Appendix B. Calculation of Concentrations from Photovac 10S30 Peak Areas.
U-Tube 5036-3
Product R
Date 7/21/87



INJ Vol '
ll'IU VVI
/ml\ f^flln
0.10 2
Isobutylene STD Cone, (ppm)  57
STD inj. vol.(ml) = 0.02
STD Gain - 2
STD Area (sqmm) - 29

Peak 1 Peak 2
Elut. t Area Elut. t
imin\ fcnmnri Concentration lm\n]
3.5 312 122.65
* v-

Page 4
K- 0.07862068
Where K - (STD Cone. * STD inj volume * STD Gain) / STD Area

Cone, of Sample  (K * A)/ (VG)
Where A,V and G are sample Area, Volume, and
Peak 3
Area Elut. t Area
(sgrnrn) Concentration (rnin) isommi Concentration
o.oo o.oo


Gain, respectively.

Total Measuring
Concentration Point/
122.65 midpoint

-------
                                        Appendix B..  Calculation of Concentrations from Photovac 10S30 Peak Areas.                                   Page 5



U-Tube  8020-1        Isobutylene STD Cone, (ppm) -     57          K= 0.114                                                   .
product     D                     STD inj. vol.(ml) -    0.02            Where K = (STD Cone. * STD inj volume * STD Gain) / STD Area
   Date  7/24/87                         STD Gain-     2
INJ Vol
fmh
^iTIIj
0.01

0.01
0.01
0.01

  fiain
2

''2
2
2
Peakl
Elut. t

3
3
3
3
3
STD
Area
i so mm i
16
18
18
49
42
Area (sqmm) -
Concentration
91.20
102.60
102.60
279.30
239.40
20
Peak 2
Elut. t
(mini
6
6
6
6
6
Cone, of Sample - (K * A)/ (V'G)
Where A,V and G are sample Area, Volume, and
Peak 3
Area Elut. t Area
(sqmrm
80
115
70
158
162
Concentration (min)
456.00
655.50
399.00
900.60
923.40
teomml Concentration
0.00
0.00
0.00
0.00.
0.00
Gain, respectively.
Total
Concentration
547.20
758.10
501.60
1179.90
1162.80
Measuring
Point/
Elapsed
Time
Elbow
Midpoint
0
4 -
10

-------
Appendix B.  Calculation of Concentrations from  Photovac 10S30 Peak Areas.
Page6
U-Tube 8020-2
Product U
Date 7/24/87



INJVol
/ml\ '>/"isitn
inn/ 'Uaiii
0.01 . 2
0.01 !'%
Isobutylene STD Cone, (ppm) -




Peakl
Elut. t
I mm}
3
3
STD inj. vol.(ml) -

STD


Area
(samrnl
17
28
STD Gain -
Area (sqmm) =



Concentration
96.90
159.60
57
0.02
2
20
K=



0.114
Where K - (STD

Cone, of Sample

Cone.

-(K*

* STD inj

A)/ (VG)

volume * STD



Gain) / STD Area






Where A,V and G are sample Area, Volume, and Gain, respectively.
Peak 2
Elut. t
ImM


Peak3
Area
(sqmrm
6 88
6 100

Concentration
501.60
570.00
Elut. t
fmin)


Area
teqmrm



Concentration
0.00
0.00
Total
Concentration
598.50
729.60
Measuring
Point/
Elbow
Midpoint

-------
Appendix B.- Calculation of Concentrations from Photovac 10S30 Peak Areas.
Page?
U-Tube 8020-3
Product U
Date 7/24/87

Isobutylene STD Cone, (ppm) -
STD inj. vol.(ml) -



STD
STD Gain 
Area (sqmm) -
57
0.02
2
20
K-



0.114
Where K - (STD

Cone, of Sample

Cone.

.(K*

* STD inj

A)/ (V*G)

volume * STD



Gain) / STD Area






Where A,V and G are sample Area, Volume, and Gain, respectively.

INJVol
(nih Gain
0.01 ,_\2
0.01 .':&
Peakl
Elut. t
(mini
3
3

Area
teqmml
24
30


Concentration
136.80
171.00
Peak 2
Elut. t
(min)


Peak 3
Area
(sqmmV
6 54
6 60

Concentration
307.80
342.00
Elut. t
(min)


Area
(sqmml



Concentration
0.00
0.00
Total
Concentration
444.60
513.00
Measuring
Point/
Elbow
Midpoint

-------
                                         Appendix B.  Calculation of Concentrations from Photovac 10S30 Peak Areas.                                   Page 8


U-Tube  8020-4        Isobutylene STD Cone, (ppm) -    57          K= 0.114
Product   SU                    STD inj. vol.(ml)    0.02            Where K - (STD Cone. * STD inj volume * STD Gain) / STD Area
   Date 7/24/87                         STD Gain -     2
                                STD Area (sqmm) *    20             Cone, of Sample - (K * A)/(V'G)
                                                                    Where A,V and G are sample Area, Volume, and Gain, respectively.     Measuring
                  Peakl                           Peak 2                           Peak 3                                              Point/
INJVol            Elut. t      Area                    But. t     Area                Elut. t    Area                       Total          Elapsed
  fmll   -6aln     fminl    (sqmml   Concentration    (mini    (sqmml Concentration   (mini   (samml  Concentration CgncepUatlon.	limi
  0.01     :':2        3         14        79.80         6       25      142.50                         0.00             222.30           Elbow
  0.01   "'*2        3         29        165.30         6       35      199.50                         0.00             364.80          Midpoint

-------
                                         Appendix B.. Calculation of Concentrations from Photovac 10S30 Peak Areas.                                   Page 9



U-Tube  8020-5        Isobutylene STD Cone, (ppm) -     57         K= 0.114
product    R                     STD inj. vol.(ml) -    0.02            Where K - (STD Cone.' STD inj volume * STD Gain) / STD Area
   Date 7/24/87                         STD Gain     2
                                STD Area (sqmm) -     20             Cone, of Sample - (K * A)/ (V*G)
         ''.                                                       Where A,V and G are sample Area, Volume, and Gain, respectively.    Measuring
                  Peakl                           Peak 2                           Peaks                                              P'nt/
INJ Vol           Elut. t      Area                   But. t     Area                 Elut. t    Area                       Total          Elapsed
_Jmll_-JBairj_^Jfflin)     'fiqm>   concentration     fmini    (somrm  Concentration _(mini_ isflmmi concentration    CpncentrpUon	Time
  0.10     ;;2        3         5          2.85         6        14        7.98                         0.00            10.83           Elbow
  0.01   ":^2        3         10        57.00         6        33       188.10                        0.00            245.10         Midpoint
  0.1      V2        3         42        23.94         6        135       76.95                         0.00            100.89         Midpoint

-------
Appendix B. .Calculation of Concentrations from Photovac 10S30 Peak Areas.
                                                                                                         Page 10
U-Tube 8043-1 Isobutylene STD Cone, (ppm) - 57
Product D STD inj. vol.(ml) - 0.02
Date 7/23 STD Gain- 2
4" DIA Vapor Well STD Area (sqmm) - 21
TCE Spill Off site
Peakl Peak 2
INJ Vol
imn
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50

  Gain
.''2

''"2
2
2
2
2
2
2
Elut. t

4
4
4
4
4
4
4
4
4
Area
(samm)
20
0
21
29
31
33
34
34
36

Concentration
2.17
0.00
2.28
3.15
3.37
3.58
3.69
3.69
3.91
Elut. t
(mini
5
5
5
5
5
5
5
5
5
K-
Area
(sqmm)
0
21
0
0
0
0
0
0
0
0.10857142
Where K - (STD Cone. ' STD inj volume * STD Gain) / STD Area
Cone, of Sample - (K * A)/ (V*G)
Where A,V and G are sample Area, Volume, and Gain, respectively.
Peak 3

Concentration
0.00
2.28
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Elut. t
(mini
9
9
9
9
9
9
9
9 .
9
Area
(sqmmL
90
28
105
123
117
126
123
129
126

Concentration
9.77
3.04
11.40
13.35
12.70
13.68
13.35
14.01
13.68
Total
Concentration
11.94
5.32
13.68
16.50
16.07
17.26
17.05
17.70
17.59
Measuring
Point/
Elapsed
Time
midpoint
0
2
6
12
15
21
25
29

-------
Appendix B.- Calculation of Concentrations from Photovac 10S30 Peak Areas.
Page 11
U-Tube 8043-2 Isobutylene STD Cone, (ppm)  57
Product R STD inj. vol.(ml) - 0.02
Date 7/23 STD Gain- 2
4" DIA Vapor Well STD Area (sqmm) - 21
TCE Spill Offslte
Peakl Peak 2
INJ Vol
(ml)
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50

' "pain
,-''2
"'^2
2
2
2
2
2
2
2
:J2
Elut. t
(mini
4
4
4
4
4
4
4
4
4
4
Area
(sqmm)
19
20
21
23
23
21
22
22
24
22 -

Concentration
2.06
2.17
2.28
2.50
2.50
2.28
2.39
2.39
2.61
2.39
Elut. t
(min)
9
9
9
9
9
9
9
9
9
9
K-
Area
(sqmm)
44
50
60
72
74
68
78
75
80
78
0.10857142
Where K  (STD Cone. * STD inj volume * STD'Gain) / STD Area
Cone, of Sample  (K * A)/ (V*G)
Where A,V and G are sample Area, Volume, and Gain, respectively.
Peaks

Concentration
4.78
5.43
6.51
7.82
8.03
7.38
8.47
8.14
8.69
8.47
Elut. t Area
(min) (sqmm) Concentration
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Total
Concentration
6.84
7.60
8.79
10.31
10.53
9.66
10.86
10.53
11.29
10.86
Measuring
Point/
Elapsed
Time
midpoint
0
2
7
10
14
18
24
26
31

-------
Appendix B.-  Calculation of Concentrations from  Photovac 10S30 Peak Areas.
Page 12
U-Tube
Product
Date
INJVol
Sml\
^Illl^ _
0.01 .
0.5
0.5
0.5
0.5
0.5
0.5
0.5
8049
D
7/23

 Rain
.'J-2
r$2
'^
2
2
2
2
2
Isobutylene STD Cone, (ppm)  57
STD inj. vol.(ml) - 0.02
STD Gain - 2
STD Area (sqmm) - 21
Peak 1 Peak 2
Elut. t
...
4
4
4
4
4
4
4
4
Area
fsamml
0
6
0
0
0
0
0
0

Concentration
0.00
0.65
0.00
0.00
0.00
0.00
0.00
0.00
Elut. t
(mini
9
9
9
9
9
9
9
9
K-
Area
(sqmrm"
0
6
0
0
0
0
0
0
0.10857142
Where K - (STD Cone. * STD inj volume * STD Gain) / STD Area
Cone, of Sample - (K * A)/ (V*G)
Where A,V and G are sample Area, Volume, and Gain, respectively.
Peaks
Elut. t
Concentration (mini
0.00
0.65
0.00
0.00
0.00
0.00
0.00
0.00
Area
(sqmml Concentration
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Total
Concentration
0.00
1.30
0.00
0.00
0.00
0.00
0.00
0.00
Measuring
Point/
Elapsed
Time
midpoint
0
3
6
10
17
23
30

-------
Appendix B.. Calculation of Concentrations from Photovac 10S30 Peak Areas.
U-Tube 8052-1 Isobutylene STD Cone, (ppm) - 57 K- 0.10363636
product u STD Inj. vol.(ml) - 0.02 Where K  (STD Cone. * STD inj volume * STD Gain) / STD Area
Date 7/22 STD Gain- 2

Peak 1
iNJVol Elut.t
/ml\  " r^oin fmin^
0.02 2 4
0.02 '.'':'& 4
0.02 ':1J2 4
0.02 2 4
0.02 2 4
0.02 2 4
0.02 2 4
0.02 2 4
0.02 2 4
0.02 ;2 4
0.02 -~2 4
0.02 2 4
*
STD Area (sqmm) - 22
Peak 2
Area Elut. t
(somrrrt Concentration. fining
0 0.00 6
0 0.00 6
0 0.00 6
0 0.00 6
0 0.00 6
0 0.00 6
0 0.00 6
0 0.00 6
1 2.59 6
1 2.59 6
4 10.36 6
4 10.36 6
*
Cone, of Sample - (K * A)/ (V*G)
Where A.V and G are sample Area, Volume, and Gain, respectively.

Area
fsqmm)
12
6
15
10
11
8
10
11
15
16
22
22


Cpncentration
31.09
15.55
38.86
25.91
28.50
20.73
25.91
28.50
38.86
41.45
57.00
57.00

Peak 3
Elut. t Area
(mip) (sqmrm Concentration
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00


Total
Concentration
31.09
15.55
38.86
25.91
28.50'
20.73
25.91
28.50
41.45
44.05
67.36
67.36

Page 13
Measuring
Point/
Elapsed
Time
midpoint
0
3
5
8
11
15
19
23
28
31
36
*,

-------
Appendix B., Calculation of Concentrations from Photovac 10S30 Peak Areas.
Page 14
U-Tube
Product
Date
JNJ Vol
tm\)
0.02
0.02
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.02
0.02
8052-2
SU
7/22

"Gain
.-!':'2
""|.2
'-12
2
2
2
2
2
2
*:2
2
2
2
Isobutylene STD Cone, (ppm)  57
STD inj. vol.(ml) = 0.02
STD Gain = 2
STD Area (sqmm) - 22
Peak 1 Peak 2
Elut. t
(min)
4
4
4
4
4
4
4 .
4
4
4
4
4
4
Area
{sqmm)
0
0
1.5
2.5
3
6
8
20
27
29
34
13
16

Concentration
0.00
0.00
0.78
1.30
1.55
3.11
4.15
10.36
13.99
15.03
17.62
33.68
41.45
Elut. t
(min)
6
6
6
6
6
6
6
6
6
6
6
6
6
K-
Area
fsqmmV
0
0
7
9
6
14
20
24
33
42
58
14
15
0.10363636
Where K - (STD Cone. * STD inj volume * STD Gain) / STD Area
Cone, of Sample - (K * A)/ (VG)
Where A,V and G are sample Area, Volume, and Gain, respectively.
Peak3

Concentration
0.00
0.00
3.63
4.66
3.11
7.25
10.36
12.44
17.10
21.76
30.05
36.27
38.86
Elut. t Area
(min) (samm) Concentration
0.00
0.00
0.00
0.00.
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Total
Concentration
0.00
0.00
4.40
5.96
4.66
10.36
14.51
22.80
31.09
36.79
47.67
69.95
80.32
Measuring
Point/
Elapsed
Time
midpoint
0
2
3
6
9
11
14
17
20
24
28
32

-------
Appendix B.-  Calculation of Concentrations from Photovac 10S30 Peak Areas.
Page 15
U-Tube 8052-3
Product R
Date 7/22/87

INJVol
fml\
""" .
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10


Gain
;-:2
'^2
H2
2
2
2
2
2
2
Isobutylene STD Cone, (ppm) -
STD inj. vol.(ml) -
STD Gain -
STD Area (sqmm) -
Peakl
Elut. t
(min)
0
0
0
0
0
0
0
0
0
57
0.02
2
22
K-
0.10363636
Where K - (STD Cone. * STD inj volume * STD Gain) / STD Area
Cone, of Sample . (K * A)/ (V*G)
Where A.V and G are sample Area, Volume, and Gain, respectively.
Peak 2
Area
fsamm)
0
0
0
0
0
0
0
0
0

Concentration
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Elut. t
(mini
0
0
0
0
0
0
0
0
0
Area
fsqmml
0
0
0
0
0
0
0
0
0

Concentration
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Peak 3
Elut. t Area
_Imini- Jaamml Concentration _
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00

Total
Concentration
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Measuring
Point/
Elapsed
Time
midpoint
0
2
6
9
13
18
23
49

-------
Appendix B.  Calculation of Concentrations from Photovac 10S30 Peak Areas.
Page 16
U-Tube
Product
Date
INJ Vol

0.10
0.10
0.10
0.10
0.10
0.10
0.10
1.00
1.00
8054
U
7/22/87

'Gain
. 2
'V .2
12
2
2
2
2
2
2
Isobutylene STD Cone, (ppm) - 57
STD inj. vol.(ml) - 0.02
STD Gain - 2
STD Area (sqmm)  22
Peak 1 Peak 2
Elut. t
(mini
6
6
6
6
6
6
6
6
6
.Area
fsamm)
0
0
0
0
0
0
0
5
8

Concentration
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.26
0.41
Elut. t
(min)
9
9
9
9
9
9
9
9
9
K-
Area
(sqmm)
0
0
0
0
0
0
0
1
2
0.10363636
Where K - (STD Cone. * STD inj volume * STD Gain) / STD Area
Cone, of Sample - (K * A)/ (V*G)
Where A,V and G are sample Area, Volume, and Gain, respectively.
Peak 3

Concentration
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.05
0.10
Elut. t Area
_(min)_isflmmi Concentration _
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Total
Concentration
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.31
0.52
Measuring
Point/
Elapsed
Time
: Elbow
.Midpoint
0
5
9
14
19
20
29

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Appendix B,- Calculation of Concentrations from Photovac 10S30 Peak Areas.
Page 17
U-Tube 8265
Product U
Date 7/20/87
INJ Vol
fmh
mm.^
1.00
0.10
0.10
0.10
0.10
0.50
1.00
1.00
1.00

".-ttain
:: 2
".-2
2
2
2
2
2
2
2
Isobutylene STD Cone, (ppm) - 57
STD inj. vol.(ml) - 0.02
STD Gain - 2
STD Area (sqmm) - 15.7
Peak 1 Peak 2
Elut. t
(m\r\]
4
4
4
4
4
4
4
4
4
.Area
(so mm}
39.7
0
0
2.5
2.5
19
28
31
28

Concentration
2.88
0.00
0.00
1.82
1.82
2.76
2.03
2.25
2.03
Elut. t
(mini
7
7
7
7
7
7
7
7
7
K-
Area
(sqrpm)
7.7
0
0
0
0
19
53
50
47
0.14522292
Where K  (STD Cone. * STD inj volume * STD Gain) / STD Area
Cone, of Sample  (K * A)/ (VG)
Where A.V and G are sample Area, Volume, and Gain, respectively.
Peak 3

Concentration
0.56
0.00
0.00
0.00
0.00
2.76
3.85
3.63
3.41
Elut. t Area
JsM- -(summX Concentration _
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Total
Concentration
3.44
0.00
0.00
1.82
1.82
5.52
5.88
5.88
5.45
Measuring
Point/
Elapsed
Time
midpoint
0
5
7
10
13
19
24
31

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