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F���Soil: 2-15.6 yrs based on observed rates of biodegradation in aerobic soils under field conditions. <br /> Avg.half life of-12 yrs in 3 different soils for-50 ppm in soil.(conversion of p,p'-DDT to p,p'- <br /> DDE). <br /> Environmental Fate Rate Constants or Half-Lives: <br /> Volatilization:Half-life of 3.7 d for water depth of 1 m, from soil w/h-1 of 578 It <br /> Oxidation:Photooxidation half-life of 168-8400 It in water, 17.7-177 h in air <br /> Hydrolysis:Estimated first-order half life of 22 yr <br /> Biodegradation:Aqueous aerobic half-life of 2-15.6 yrs <br /> DDE. Common name: DDE(p,p'-DDE;op'-DDE),product of DDT degradation. <br /> Half-lives in the environment: <br /> Air:Atmos.transformation lifetime est,to be< 1 d. <br /> Surface water:Hydrolytic half-life of >120 yr,est.half-life>300 d in lakes. <br /> Groundwater:N/A <br /> Sediment:N/A <br /> Soil:Field half life of 1000 d <br /> Biota: Elimination half-life of 340 d(rainbow trout),300 d for birds. <br /> Environmental Fate Rate Constants or Half-Lives: <br /> Volatilization:N/A <br /> Oxidation:N/A <br /> Hydrolysis:>120 yr <br /> Biodegradation:N/A <br /> .�DDD. Common name:DDD,TDE(tetrachlorodiphenylethane),product of DDT deg. <br /> Half-lives in the environment: <br /> Air: 17.7-177 h <br /> Surface water: 2-15.6 yr. Groundwater: 1680-270,000 h based on anaerobic soil study data <br /> Sediment:N/A <br /> Soil:Field half life of 2-15.6 yrs based on observed rates of biodeg. of DDT <br /> Biota: 119 hr in mussels. <br /> Environmental Fate Rate Constants or Half-Lives: <br /> Volatilization:Aquatic approx. 1 mo. <br /> Oxidation:Aquatic half-life approx. 22 yr <br /> Hydrolysis:half-life of 570 d @ pH 9 and 190 yr @ pH 5 <br /> Biodegradation:Aqueous aerobic half-life of 2-15.6 yr <br /> 5.0 CONCLUSIONS AND RECOMMENDATIONS <br /> 5.1 From visual observations, there is no surface contamination on the subject property. The <br /> date of the last inspection of the property was June 14, 2006. Section 9-905.12 of San Joaquin <br /> County Development Title states "Corrective Action: If the report indicates there are surface and <br /> subsurface contamination, corrective action shall be recommended in the report and concurred with <br /> by Environmental Health prior to the issuance of the building permit." Therefore, it is my <br /> professional opinion that no corrective action is required on the two proposed Parcels that are to <br /> compose the subject property. <br /> The probability of subsurface contamination from pesticides,or other types of agrichemicals, can be <br /> considered extremely low-to-nonexistent. The depth to groundwater of 150 feet would make <br /> impact from adverse constituents a much lower probability in comparison to a shallow groundwater <br /> depth. <br /> Page -6- / <br /> Chesney Consulting <br />