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FFLannate. Common name- Methomyl. Half-lives in the environment: Air: estimated to be 1.4 months based on rate constants. Surface water: experimental half life of 262 d has been determined in pure water. Groundwater: half-life of<0.2 d in GW samples. Soil: field half life of 30 d. Biota half-life of approx 3-5 d in plants following leaf application. Dimethoate. Half lives in the environment: Air: 0.49 hrs. Surface water: 264-1344 hrs based on biodegradation half life. Groundwater: 528-2688 hrs based on estimated biodegradation half-life. Soil: 264-888 hrs based on soil die-away test data and phytolysis half-life of 7-10 d on soil surface. Biota: disappearance rate and half- life from treated tomato plants - 3.4 d for tomato leaves and 2.4 d for tomato fruits. Treflan. Half lives in the environment: Surface water: calculated half-life of 21 min from midday direct sunlight phytolysis. Half lives of<20 d for 2.5-5.0 cm water over flooded soils. Sediment: degradation half-life of 9 d in sediment. Soil: estimated persistence of 6 mos in soil. Lorsban Common name: Chloropyrifos. Half lives in the environment: Air: 6.34 hrs for the vapor phase reaction. Surface water half life estimated at 9 d for model river 1 m deep. Groundwater/sediment: half-lives of 24 d in 10 g untreated sediment. Soil: 17 weeks in sterile sandy loam and>24 wks in organic soil. Phytolysis half-life of 22 d determined under midday summer sunlight. CONCLUSIONS AND RECOMMENDATIONS From visual observations, there is no significant surface contamination of hazardous materials. The probability of subsurface contamination from pesticides can be considered very low-to- medium low, considering the environmental fate data presented and soil type. Groundwater testing for nitrate and DBCP must be performed at the time of the Soil Suitability Study. We suggest the water from the existing residence and any future wells that may be drilled on any of the four parcels be tested for a Multi-residue screen consisting of analysis for Dinitroanaline, Triazine, Organochlorine and Organophosphates. This is a precautionary measure and does not indicate these chemicals occur in the underlying groundwater. It is our opinion that contamination originating from the existing septic tank is unlikely. Contamination is usually dependent upon the age and type of tank construction material. The next time the tank is pumped out,the sewage contractor can check the integrity of the tank. Considering the 1.) depth to groundwater, 2.)the underlying high clay content soil strata and 3.) the low density housing in the area,the probability of pathogen and/or nitrate contamination from the on-site and surrounding septic systems is unlikely. Asbestos containing materials (ACM)testing from any portion of the existing buildings is outside the scope of this investigation. If the existing buildings are ever demolished,testing for ACMs should be done at that time. 4 va(.fey Ag search