|
Ern.w. =•.:e_ 3pi.r-,r_:dA:�''w... - l"`� �._ ,.a �.a'.•�i.�'. '`,.+.*,,,'
<br /> .n ,� Sx:r in,,. w ,a .f.�.�5"eexa•-�� '„�y"8, '.n.n n.. f v,rt ,P+_, ..� ,pr rt ".,A -ezS 1-c. � � ,-� �k[-,k,-, +,r 4 i,r y 1 �;
<br /> K
<br /> �' -' ,.7 {'I - A''If AC:�l�j''Qa +.r^•-n. v-.w•o.a-,r-+-�rm �rM- - - � �vie.c...����..uf'C '
<br /> ,� - '''�• _ -;,,,•rc. �� 'i' •�Zii� p 7-.� rry�*nv`�1+�,•�+o-'°"a _'r`r xc4�-i" .'.�""'.c;:- �n-rKmr
<br /> � •7t. '.;J-,,gyp' 'c. _ t. s• :ky �•-r'.fi-
<br /> r40•c -�c<..-
<br /> tt PHASE I SUBSURFACE WVESIIGAIM WSULTS U*jiow
<br /> 1605 SOM B Dorado.SlocAlon•Caltloenla
<br /> H
<br /> 3.0 RIESULTS
<br /> r, 3.1 Soil Borin, ag__nd Soil Sarnplin�
<br /> r On July 2 and 3, 1991, three 10-Inch-diameter soil borings (MW-1, MW-2, and MW-3)
<br /> were drilled on site by West Hazmat Drilling Company of Rancho Cordova, California
<br /> (Figure 2). The borings were drilled using a Model CME-75 drill rig under the supervision
<br /> of Aegis personnel. All three borings were drilled to a depth of 55 feet below surface.
<br /> Soil samples were collected from each boring at 5-foot intervals for hydrogeologic
<br /> a descriptions and possible laboratory analyses. The soil samples were analyzed for TPPH
<br /> as gasoline, BTEX, EDB, and EUG by CAL DHS(TPH draft and EPA Method 8240/8260.
<br /> fn addition, the soil samples collected from the drill cuttings were analyzed for organic
<br /> lead. The laboratory analytical reports and chain-of-custody forms are located in
<br /> Appendix B.
<br /> The soils and alluvial materials encountered during the drilling consisted of silty clays from
<br /> -; 1 to approximately 25 feet below surface; sand from approximately 25 to 31 feet below
<br /> surface; silty clays and clayey silts from 31 to 49 feet below surface; sands from
<br /> b approximately 49 to 55 feet below surface with soil boring termination in sandy end silty
<br /> - clays at 55 to 56.5 feet below surface.
<br /> Groundwater was encountered during drilling at approximately 46 feet below surface in
<br /> each of the borings. Soil boring logs are included in Appendix C,
<br /> Petroleum odors were not present in any soil samples. Measurements for organic vapors
<br /> } from soil samples collected on the PID from soil boring 1 (MW-1) ranged from 0 to
<br /> 45 ppm; soil boring 2 (MW-2) ranged from 0 to 200 ppm, and sail boring 3 (MW-3)
<br /> indicated readings at 0 ppm. The PID readings are recorded on the soil boring logs
<br /> located in Appendix C.
<br /> rl]R
<br /> 3.2 Groundwater Monitoring Well installation and Development
<br /> Four-inch-diameter wells were installed in each boring. The three wells were installed in
<br /> I' similar fashion, with the screened interval extending from 35 to 55 feet below surface.
<br /> ;F
<br /> The top of the screened interval was placed in silt above the top of static water by
<br /> Q approximately 10 feet to allow for groundwater level flumuations. Refer to Appendix C for
<br /> well completion details. The well screen slot size is 0,01 inch and the filter pack material
<br /> is composed of#2/12 Lonestar sand. All three wells were developed on July 3, 1991,
<br /> a using a drill-truck operated surge block and pump.
<br /> h
<br /> 91-044&RPT _4 -
<br />
|