SU0007889 SSC RPT - Laserfiche WebLink

Home Browse Search

��-ti § 3.4 Descriptionf a pat off-site poten al and/or known above and below ground sources of contaminat on-ide .d..i.I rea of the project site that or may-impact the project site includes:. Information conveyed by the February,9, 2006 and the-June 18' 2009 Envisions Program Documents indicates no listings on or in proximity,to-the subject property., The two closest Leaking Underground Fuel Tanks (LUFTs) are approximately two miles to the . east: Due to.changing groundwater gradients, it is unknown if this site can be considered upgradient to the.property. However, this site and any leaking contents could not affect the subject property due to the distances`involved. Agricultural spray drift(non-target) from the nearest agricultural production land affecting the property could be-a possibility, since agricultural production occurs all around the subject property. The region has been, and continues to be intensely farmed, so nitrate contamination to the underlying groundwater from nitrogen fertilization may be considered a possibility As referenced above., nitrate.contamination may be mitigated-by large.bodies of _ fresh water. The agrichemical DBCP has been also detected in well water in this locale. The science ofpesticide residues in soil; air; surface water and.groundwater is extremely , complex and'variable. Environmental models that attempt to predict pesticide behavior and mow- transport in the environment are beyond the scope of this investigation. Agricultural pesticide docu'mentationwas obtained directly from Lassen Farms, Inc. Lassen Farms.leases the property from Mr. Larson and farm,sthe property. The pesticide application document found in Appendix C illustrates Lassen_Farms pesticide application records of yearly applied materials. No agrichemical materials are mixed on the subject property. Available Environmental Fate Data for the pesticides used on the property was obtained frorn the U.C. Davis and Oregon State University Extoxnet System, and is also found in Appendix C. The Fate Data indicates most of the applied pesticides have comparatively short half-lives. As referenced below, 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. The following chart summarizes the available Environmental Fate Data for the name and type of agrichemicals applied'to the subject property. Noted times,of duration are maximum values observed. 'The Fate Data is highly specific for various environmental conditions, and is normally expressed as half-lives in terms of days. _ :Page-5- Chesney Consulting. .