SR0043178 SSNL - Laserfiche WebLink

Home Browse Search

K LLEI N FFELDER F4. 4. GROUNDWATER Groundwater .was not encountered in our soil profile pit excavated for this investigation. Lines of Equal Depth to Groundwater contour maps published in groundwater reports by the San Joaquin County Flood Control and Water Conservation District (1981 to 1999) show groundwater levels in the project area ranging from about 75 to 105 feet below ground surface. Based on Lines of Equal Elevation of Groundwater contour maps, the groundwater gradient in the project area is generally from northwest to southeast. Local gradient variations may occur due to well usage. Groundwater from a well on the northern portion of the site is currently used primarily for domestic purposes. We anticipate that the predominant use of groundwater will remain the same upon completion of the proposed improvements. On June 27, 2005, samples of groundwater were obtained using clean procedures from a spigot at the head of the domestic well at the adjoining property. A permit for a pump replacement was on file with SJCEHD. However, a permit for the well installation was not encountered, and details of the well are not known to us. The water samples obtained from the well were delivered to a laboratory that same day using chain-of-custody procedures for DBCP and nitrate (N) testing. The results of the analysis indicate a nitrate (N) concentration of 1.3 mgll and that DBCP was not present in detectable amounts. This nitrate concentration is below the state drinking water standard. Copies of the test results and the chain-of-custody are attached. i There is no known well located on the subject property for the new ministry center, and groundwater is not currently used at the site. We understand that a well will be constructed to provide water to the proposed ministry center. We anticipate that the predominant use of groundwater will be for domestic and landscaping purposes. We do not know of groundwater contamination issues at the site at this time. There are no known on-site underground storage tanks or adjacent dairies. The potential exists for groundwater to be contaminated through the use of pesticides and herbicides on nearby orchards. Potential sources of nitrate to soil and groundwater include fertilizer that may be used in the area and septic usage in the project area, fit including the proposed residence. 5. SOIL PROFILE Fi The subsurface conditions at the site were explored on May 16, 2005, by drilling two borings to depths of approximately 16'/2 and 11'/2 feet below existing grade within the proposed building area, and one boring to depth of about 261/2 feet in the location of the proposed septic tank. The borings were drilled using a Simco 2400 truck-mounted 56915.G011ST05R823 August 30,2005 ©2005 Kleinfelder,Inc. Page 3 of 8