. . . /./1) .1­

SAMPLING METHODOLOGY

During March and April 1983, EPA's Regional Field Investigation Team performed a perimeter soil sampling survey. The areas which were investi· gated are ·designated on the attached maps as areas 1, 2. and 3.

On June 13-16, EPA's Region I TAT Team expanded upon the FIT surveyin the three above mentioned areas and, also. surveyed the area designated as area 4. In areas 1 and 2, the FIT data was reviewed. The FIT samplingstations which denoted the leading edge of the contamination were approxi­mately located and were marked with surveyor's tape. Using a metal tape,the crew marked off a predetermined distance (for area 1. 25ft. and for area 2. 15 ft) out from these points. to locate the new sampling points.At each location. a 6• deep hole was dug. The OVA probe was inserted into the hole and a total volatile organic reading was recorded. If the reading was 1 ppm or greater, the crew moved an additional increment away from the site. to locate the next sampling station. This process was repeated until a reading of less than 1 ppm was obtained. Maps and data for area 3 were unavailable and area 4 was not previously surveyed. For both areas. original sampling stations were located at 25' intervals along the fence. at a dis· tance of 5' from the fence. In areas where contamination was discovered. the subsequent sampling stations were moved back in 10 ft. inc.-.ents until a •clean• station was reached.

II t NSCALEI ••• 100' I

SAMPLE AREA 1

- SAMPLE AREA 2 • SAMPLE AREA 3

- SILRBSIM PBNCB

-&WALE

DBA 3 OVA .RBADINGS IN AREA AREA 2

OVA READINGS IN ~ GRD'l'IR '1'8AN 1000 ppt IN AREA Nl OP ~ LESS 10 PP111

RMGB PR<II 3 '1'0 60

J

-~·

~~~TM SITE: SAMPLE AREA 1

NOTE: TOtal contaminated aurface area approx­imately 60,000 aq.f •

0 0

ARROW CARRIER

....•,"i. .... ,~

0' 50' 1._,____ . !!!

8ILIIUIM I'DCS

• IWCPI.& ftATIC»>S

- -r.at'Oili.D..te OOOUa· iMUoD by PIT

SILRESIM SITE: SAMPLE AREA 2

NOTE a Total contaminated aurface area approximately 1,050 aq.ft.

PERa£0 TANk BLDG.

...____o· so•

KEY

-....Approximate contam1nat1on by FIT

~ppro•~te contam1nat1on by TAT

-----SILRESIM FENCE

• SAMPLE STATIONS -tt-sWAIL

NOTE: All values are reported 1 n ppm.T denotes SlfiiP11ng by TAT Team.

SILRESIM SITE: SAMPL~ AREA 3 o...·------=.6' • f a

NO'l'EJ Total contaminated .ur!ace area approximately 1,000 aq.ft.

- SILRESIM FENCE

• SAMPLE STATIONS

NOTE' All valuea are reported in pp T denote• Nlll ­pling by TAT Teu.

(f) SAMPLE STATION HUMBER

..Approximate con­tuination by TAT

SlLKt~!M Slit: ~AMPLE AREA 4 o• 67'

!5!!.

-SILRESIH FENCE

.. • SAMPLE STATIONS

NOTE a All valuea are reported in~· T cSenotea aciaplin by TAT Team.

(I) SAMPLE STATION NUMB

•