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"—T'ABLE 1 -CHECKLIST OF REQUIRED DATA
<br /> FOR:NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: City of Stockton Fire Station#3,1116 First Street,Stockton,CA,San Joaquin County
<br /> One municipal wafer well was identified 1600
<br /> y 1. Distance to production wells for municipal,.domestic,agriculture,industry feet downgradient of the site. The closest
<br /> and other uses within 2000 feet of the site; surface water is Mormon Slough,1700 feet north
<br /> (crosagradlentj.
<br /> In 1989,1989,one 530-gallon gasoline
<br /> 2: Site maps; to scale,of area impacted showing locations of former and existing,tanksystems, UST and associated piping were
<br /> excavation contours and sample locations,boring and monitoring welletevatr`on contours, removed from the site. A 550-
<br /> gradients,and nearby surface wafers;buildings, streets,and subsurface utilities; gallon diesel tank was
<br /> previously removed and closed.,
<br /> t v—i Lithology consists of clay to 8 Beet bgs,then
<br /> 1 1 3. Figures depicting tithology(cross section), treatment system diagrams; predominantly sand with clay and slit layers to
<br /> at least 65 feet bgs.
<br /> L I 4. Stockpiled Soi't rerrtaining ori-site-or site disposal(quantity); h°soil removed.
<br /> Y j'he three on-site;monitoring wells will.be destroyed,pending closure catrcurrerece•
<br /> S.Monitoring wells reri1af ftig ori si(e;fate;
<br /> ---� - Groundwater efevatfo»swr d6dfrOMj4 tW-37feet:bgs,16
<br /> L--!J
<br /> t7. Tabulatedre$*of`al!l96rot[ndr+vater:elevations.and"depths>to water; on east northeasterly#o.easteriy#oi` rlirecfiorr..
<br /> Contamination appears to be confined to soil and groundi#g in the tank:plf
<br /> T.Tabulated results of all sampling and analyses: area, Groundwater co»centrations ofTPHg 005 pg1L)and'benterte .132 09&)
<br /> Detection limits for:c+�rlFrrrilatian sarnplirrg have decreased overtime to below detection limits. MTBE concentrations have
<br /> :Lead:analyses remained stable at 25 to 66 pg1L>
<br /> 8 Cdhd6btrati6rl contours df contaminants found and those remaining in;soil
<br /> and groundwater,and both on-site and ofF site:.
<br /> Y Lateral and. .N Vertical extent of soil contamination
<br /> Lateral:and. :.Verticatexten...t.ofgroundwafercontaminati'on
<br /> 9 done ofinfluence-calculated-and assumpticns usetl`forsubsurface
<br /> The site map shows the limits of:the.formerlank
<br /> EDremediation system and the zond:10c6pture attarned`for the soil and location,
<br /> groundwater remedia tion system,.
<br /> v 1 i).Reports f information.. unaiithodked Release:Form r-.---nQMRs(Dates) 1999
<br /> 0 n LJ
<br /> Well boring lags PAR FRP` Other(report name)3I2 b+�Closure Report=
<br /> 0MN
<br /> ?:Rest.Available.Techr#ology(BA T)used o :air explanation for not using BAT; Tho teak sources were removeditm tiie:stte..
<br /> Y
<br /> 2.Reasons why background wasls.unatfainable using BA T
<br /> The remaining hydrocarbons should naturally attenuate,
<br /> Y
<br /> The total mass of TPH,g,BTEXC and MTBE estimated
<br /> 13.Mass balance calculation of;substance treated versus Vja—tremainlngj in soliis 915, 203,an#o'i1.pounds,respectively,and
<br /> N
<br /> in groundwater is less tha»...one pound each..
<br /> 14.Assumptions;pararrrefets;calculations and model used in-risk Risk assessment shows that the on-site gw ingestion health
<br /> risk levels are exceeded forbenzene'. However,benzene was
<br /> assessments,and fate and frarrspOrt modeling,' not reported in the most recent round ofgw sampling(1212(99);
<br /> 15.Rationale why conditions remaining at site will not adversely Based on depth to gw,limited extent ofimpacted soil am gw:
<br /> Ell
<br /> ;
<br /> impact water:quality,health,or other beneficial uses,and results of the risk assessment;and distance to receptors,the:site does not represent a significant risk to human health and
<br /> the environment.
<br /> Q fib.WET or TCLP results
<br /> $y
<br /> KAT
<br /> Monitoring well MW-2 is located between the source area and the municipal well. MVN-2 Is screened shallower than the KA contaminated well in the tank excavation{30-50 feet bgs versus 45-65 feet gags}. 'Groundwater samples from MW-2 have been
<br /> Date. below reporting limits for TPH9;BTEX,MTBE,and the oxygenates since sampling began in March 1999,with one exception of
<br /> toluene at O,655 ppb. Mr_Eric Mar at the California Water Service,owner of the municipal well located 1,600 feet downgradient of
<br /> —1244 f(lo the site,stated that the municipal well is screened from 205-500 feet bgs,has not been used since about 1981,and is not likely to
<br /> r be used clue to the presence of methane. Mr,Mar also stated that the closest future drinking water wells will be located 2 to 3 miles
<br /> from the site. Mr.Mar agreed with case closure because the site should not impact their drinking water supply.
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