HomeMy WebLinkAbout[Untitled]_4-58Mr. Yam Hsing
2012 Buck Owens Blvd LUC
January 25,2O13- Page 4
PREVIOUS WORK
The ARC[> service station was constructed at the site in the late 1080a with three O'OOO'gaUon
single-walled steel gasoline U8To in o location similar to the existing U8Te and four dispensers on two
islands in similar locations ao the existing dispenser islands. The station building had two service bays
with a 500-goUon single-walled steel waste oil UST where the current mini mart building is located.
The service station was operated under Kern County Department of Environmental Health Services
(KCDEH8) Permit to Operate # 050101. In 1908 the fueling facilities were upgraded at the site with the
removal of the three 8'000-go||on single-walled steel gasoline U8To' one 500-go||on singled-walled steel
vvoota oil UST, four dispensers without secondary contminrnent, and the single walled steel product and
vapor recovery piping under KCDE8H PTA No. A-904-G and subsequent construction with the existing
three 12'000-ga||on double-walled fiberglass USTo. four W1pDovvith secondary containment on the two
islands, and double-walled fiberglass product and vapor recovery piping (see Figure 4).
Upon removal of the USTs' dispensers' and piping' 32 soil samples were collected from beneath the
locations of the former fueling facilities as well as the stockpiles of soil excavated in association with
exposing the U8Ts and product piping. The soil samples were analyzed for total petroleum hydrocarbons
(TPH) as gasoline and benzene, toluene, ethy|benzene, and total xy|eneo (BTEX). TPH as gasoline was
detected in all 32 samples, reaching a maximum concentration of 1'793.5 mg/kg in the aornp|a collected
from beneath the northern dispenser on the western island at a depth of 12 fbg. However, 28 of the 32
aannp|ea detected TPH as gasoline at concentrations less than 10 mg/kg. Benzene was detected in only
two of the 32 samp|ea, at concentrations of 8.1 and 1.3 mg/kg in the samples collected from beneath the
northern dispenser on the western island at a depth of 12 fbg and the stockpile of soil eaaVo|oted with
excavation of soil from this area (see Attachment 3 for a Summary of Previous Work).
Based upon the laboratory analytical results, the KCDEH8 issued an Unauthorized Release Report
(URR)' dated October 23, 1989' and requested performance of preliminary site assessment to evaluate
the marboa| and lateral ||rnita of hydrocarbon-containing soils and oaeeoa the potential for the petroleum
release to impact groundwater resources. On April 20, 1090, two soil borings were drilled to a depth of
45 fbg, with soil boring B-2 positioned immediately north of the northern dispenser on the western island,
and boring B-1 position ten feet to the northwest ofboring B-2. TpH as gasoline and benzene were
detected in only one of the 15 aannp|en submitted for laboratory analysis at concentrations of 10 and
0.005 mg/kg, respectively, in the soil sample oo||mchad in soil boring B-1 at depth of fbg. Based upon
the laboratory analytical results, the KCOEH8, in its letter dated August 2' 1080' issued o No Further
Action (NFA) determination with respect to additional assessment of mitigation activities at the site
(see Attachment 3).