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Although DDT was banned in 1972;its presence in San Joaquin Valley soils is indicative of its long half-life of 15.6 years. Consequently, there may be extremely small concentrations of DDT, and its degradates in the subject property soils from farming f operations that may have taken place on fhe:property decades ago. Any minute residual �� } pesticide concentrations are inconsequential in my professional opinion because the I E majority of the property will remain in agricultural production and not be developed into a residential subdivision, which would cause greater scrutiny of agrichemical residues. The environmental fate data are presented below for DDT, and its degradates DDD and DDE. I DDT. Common name: Agritan, Anofex, Azotox,et al'. Half-lives in the environment: Air: 17.7-177 h. Surface water: 73.9 h for a pond 1 m deep.Degradation half-life of about 10 yr-average from loss rates determined in Lake Michigan. Groundwater: 16 d to 31.3 yr, Sediment: 3 to 5 yr Soil:2-15.6 yrs based on observed rates of biodegradation in aerobic soils under field conditions. Avg.half life of--12 yrs in 3 different soils for-50 ppm in soil.(conversion of p,p'-DDT to p,p'-DDE). Environmental Fate Rate Constants.or Half-Lives: Volatilization: Half-life of 3.7 d for water depth.of] m, from.soil wl h-1 of 578 h Oxidation: Photooxidation half-life of 168-8400 b in water, 17.7-177 h in air Hydrolysis: Estimated first-order half life of 22 yr Biodegradation: Aqueous aerobic half-lifeof 2-15.6 yrs DDE. Common name:DDE(p,p'-DDE;o,p'-DDE),product of DDT degradation, Half--lives in the environment: Air: Atmos.transformation lifetime est.to be< 1 d. Surface water: Hydrolytic half-life of >120 yr,est. half-life>300 d in lakes. Groundwater:NIA Sediment:N/A Soil: Field half life of. 1000 d Biota: Elimination half-life-of 340 d(rainbow trout), 300 d for birds. Environmental Fate Rate Constants or Half-Lives: Volatilization: NIA Oxidation:NIA - Hydrolysis:>120 yr DDD. Common name: DDD, TDE(tetrachlorodiphenylethane), product of DDT deg. Half-lives in the environment: Air: 17.7-177 h Surface water: 2-15.6 yr. Groundwater: 1680-270,000 h based on anaerobic soil study data Sediment:NIA Soil:Field half life of2-15.6 yrs based on observed rates ofbiodeg.of DDT Biota: 119 hr in mussels. Environmental Fate Rate Constants or-Half-Lives: Volatilization: Aquatic approx. 1 mo. Oxidation: Aquatic half-life approx. 22 yr The agrichemicals, other than fertilizers, applied to the subject property are usually mixed on-site near the irrigation well. There is a triple preventative backflow measure when mixing agrichemicals: The irrigation well piping has;two backflow prevention devises and when loading spray or nurse ( �� tanks, an air gap is always maintained. Pesticides are typically applied to the cherries by ground rig. Page -6- Chesney Consulting