|
1 I
<br /> 1 CLEARWAOTER
<br /> G R O tJ P I N C '
<br /> I � —
<br /> 3.0 FIELD ACTIVITIES
<br /> ' All work was performed in accordance with Clearwater Field Procedures (previously
<br /> submitted) and under the directives and guidelines,established by the PHS/EHD and
<br /> ' the Regional Water Quality Control Board The monitoring wells were gauged and
<br /> sampled on arc 8, 1995 Prior to sampling, all wells were purged of a mirumm
<br /> u
<br /> of three saturated well volumes Well purging information 1s presented in'
<br />~ , Appendix A
<br /> / I
<br /> Groundwater samples were collected from the monitoring wells using dedicated
<br /> ' polyethylene bailers Samples were labeled, documented on a chain-of-custody
<br /> form, and placed in a cooler for transport to PACE, Inc (PACE), a DHS-certified
<br /> laboratory located in Novato, California All groundwater samples were analyzed
<br /> for total petroleum hydrocarbons as gasoline (TPHg) by EPA Method 8015 (CA LUFT
<br /> modified), and for benzene, toluene, ethylbenzene and total xylenes (BTEX) by EPA
<br /> Method 8020 (CA LUFT modified)
<br /> f
<br /> 4.0 RESULTS AND DISCUSSION,
<br /> 4.1 Water Level Manitaring Data ,
<br /> ! i t I „ I '
<br /> ' On March 8, 1995,I the'depth'to ground water in each of the well's ranged fr7 25 34
<br /> to 27 04(feet below grade. Ground w ter flow was,determined,to be northwesterly at
<br /> ' 1 an approximate ,gradient of '13.4% `O034 feet/foot) across most'nf the site In 'the'
<br /> northwest corner of the site, down radient of the former, tank excavation, the
<br /> ' groundwater flow was to the northw6st lat an approximate gradient of 0�% Plotted
<br /> on the roundwater°Contour, Map (Figure 3)' this change in gradient appears as a '
<br />` slight�ounding of the Water table in the vicinity of the former USTs A similar
<br /> 1 ,
<br /> groundwater mound was apparent in the same location during previous gauging
<br /> I I I v 1
<br /> events.
<br /> , 1 I
<br /> The site is unpaved; therefore it is likely that groundwater recharge through, the E
<br /> r ' ; vadose zone' is pr©ducing a cistern-effect -in,porous' excavation, backfill1 material, i
<br /> causing this ri-iound' feature, III mouniding'will continue to be monitoredin
<br /> r rlil r l r, I i I l i i I 1` I ' I .11 1 l e
<br /> r
<br /> future'l galuging events,, and the ' results of ,these I observations documented; in
<br /> subsequent reports
<br /> If
<br /> I f I I
<br /> v r
<br /> 1 I r i r I 1 1 1 r 1
<br /> 1 r s i
<br /> VIll
<br /> ,,l f 'H I s , y I ,
<br /> ' II r ' ' I I ' �! frt r I Ir I' 2 ,"V I i �I it rt' 1 1!' ,'S/ZS,gJ 'In
<br /> �� D-101 4Q9411 '` °' `I II N t r I 1 f H ! �E ,'! j i I E d E ,l 'I Y I€
<br /> I''I 1 r 4 �'1' I I I I !r rt E_ 1 �l f 1 1 .fir II r I
<br /> t I,t lilt
<br /> If
<br /> IIM I Iii �I Y ,r l ! li I l E �l 11
<br /> "4 GEI� �'=1r 1 ,'l'Y �� "�1`i�'�� �K r I E �' 11�'�� Ill
<br /> ,r I �l� �I�, 1 1 �� �'
<br /> 1 I " 1 11 h 1 ` 1 t p1 11� r y _ 4rlil.l V r` 1�Yrl I I I`II 1 r I
<br /> I��a,�ll��lil�r"�� � "�l�}��r` �I�°{�k� IC r i f�Y{�II I Ir I �11 tE e«r '14f 11�� M' i `h it II� I dx 1 �rI I r'I I It ' V it,'I ! 1°I' �"fin ♦' 11 , I
<br />
|