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C) E 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 of 2-15.6 yrs based on observed rates of biodeg. 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 Hydrolysis: half-life of 570 d @ pH 9 and 190 yr @ pH 5 Biodegradation: Aqueous aerobic half-life of 2-15.6 yr CONCLUSIONS AND RECOMMENDATIONS k From visual observations, there is no surface contamination of the soil on the subject property. As of the date of this report, it is my opinion that the corrective action required within the boundaries of the subject property consist of the following: OO The diesel in the referenced drum may be disposed of by separating the diesel from the water since diesel floats on water and combusting the diesel in the on-site John Deere tractor. Q It is our understanding that Pacific Gas & Electric (PG&E) owns the electrical transformers near the water well. PG&E should be contacted by Mr. Schimmel to make them aware of the oil leakage on the underside of the transformers. O The used motor oil spill on the concrete floor should be cleaned up. Mr. Schimmel is aware of each of these three concerns and will correct or address them as soon as possible, within 30 days of the date of this report. The probability of subsurface contamination from pesticides, or other types of agrichemicals, can be considered very low-to-nonexistent, considering the environmental fate data for DDT and related compounds presented above. The depth to groundwater of 65 feet would make impact from adverse constituents a lower probability in comparison to a shallower groundwater depth. Surface and subsurface soil types are heavier clay/silt type soil with a higher biological activity than in a sandy soil, and therefore, higher mitigation capacity. The probability for nitrate contamination of the underlying aquifers originating from surrounding septic systems is low due to the low density of systems in the study area. If high nitrate concentrations are found in the well water, it may be attributed to agricultural fertilizer inputs. Page -5- i Chesney Consulting