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PUBLIC ENVIRONMENTAL RECORD/DATA SOURCES Static groundwater is found approximately 100 feet under the property as illustrated on the attached 1999 Lines of Equal Depth to Groundwater map. From the 1999 Lines of Equal Elevation of Groundwater, the groundwater gradient is considerably flat. Directional flow appears to be very gently toward the southeast. As referenced, a groundwater depth of 100 feet can be considered a deep groundwater elevation which cannot be easily impacted from serious point 6�1+J source hazardous materials releases, agrichemicals such as pesticides/herbicides, or nitrates from fertilizers. The degree of impact from agrichemicals is particularly mitigated when there are intervening layers of clay or hardpan soil down to the static water table depth. It is known that a hardpan and clay strata are prevalent in this locale. As illustrated on the attached GeoTracker Site Map,there are four Underground Storage Tanks �� (USTs) and one Leaking Underground Storage Tanks(in red) in proximity to the site. The four Underground Storage Tanks are shown to be approximately two and four miles north of the property, 1) and impossible to impact it. The Leaking Underground Storage Tank is shown to be two miles to the west of the property. This location can be considered crossgradient in relation to the property. The EHD Envisions Program Information was reviewed for potential sites on Copperopolis and y� Milton Roads. The only site listed was the Henry Eilers site at 15573 East Milton Road. This site contains a faun UST and is crossgradient and approximately three-quarters of a mile northeast of the property. Two sources of information which attempt to document and define on-site and surrounding past land use were also utilized. The first is the use of aerial photographs. Aerial photographs of the subject area from 1970 through 1977 found on USDA Soil Maps show the Smythe property as it was owned by them at this time, extending to the intersection of Copperopolis and Milton Roads. The large trees are readily visible, along with an open corral area which was served by the loading chute. The USDA Soil Map shows most of the property soil to consist of an Archerdale clay loam (#107), with the northwest corner consisting of a Hollenbeck silty clay(#173). Typically, these soil types are well drained with slow permeability, and possess a high percentage of soil "fines"to impede rapid percolation of septic effluent, unlike what would occur with a sandy soil. The second source of information can be found on USGS maps. The property is Iocated within the Stockton East 1J Quadrangle Map, which shows the referenced buildings adjacent to Copperopolis Road. Noted on the Environmental Questionnaire completed by Mrs. Smythe on June 20, 2004, is the -2-3--� response to pesticide applications to the property. No pesticides have been applied to the property. Therefore, an evaluation of environmental fate data for specifically applied agrichemical residues as a ( t� nonpoint source of potential contamination was not done. In reviewing the environmental fate data of modern agrichemicals, we find most of the half-lives to be extremely short and are measured in hours. The science of pesticide residues in soil, air, surface water and groundwater is extremely complex and variable. Environmental models that attempt to predict pesticide behavior and transport in the <S� environment are beyond the scope of this investigation. However, pesticides with long half-lives that may have been used or drifted onto the property decades ago,primarily DDT, may be of a very slight concern. Page -3- Chesney Consulting