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r� a .,, NfrMrCX�[fANfA Mr Bill Vxzza 1 June 1994 Page 2 GROUNDWATER LEVEL MEASUREMENTS Groundwater levels were measured in each of the three monitoring wells on 31 March 1994 Measured groundwater levels are presented in Table 1 and were used to estimate groundwater flow direction and gradient Figure 1 presents the groundwater flow conditions for March 1994 which indicate shallow groundwater flow towards the north at a gradient of 0 0013 foot per foot GROUNDWATER SAMPLE COLLECTION On 31 March 1994, groundwater samples were collected from the three existing monitoring wells (MW-1, MW-2, and MW-3 shown on Figure 1) After measuring the water level in each well, a translucent polyethylene bailer was used to visually inspect the groundwater surface for a product layer or sheen After inspection of the water surface sample, the well was purged by bailing During purging, the groundwater field parameters of pH, electrical conductivity and temperature were monitored Purge water was placed in 55-gallon drums, labelled and stored on site For quality control, the pH meter and conductivity meter were calibrated at the beginning of the sampling day with commercially available standards Well purging activities were continued until field parameters had stabilized and a minimum of three well volumes of water were removed from the well After purging the well, groundwater samples were collected in containers prepared by the analytical laboratory according to the requirements for the specific analysis using disposable bailers Each sample container was immediately sealed and labeled to indicate a unique sample number, the project number, date and time collected, sample location and sampler's name After labelling, each container was placed in a chilled cooler and delivered under chain-of-custody documentation to Matrix Environmental Laboratories in Rancho Cordova for analysis Field information gathered during collection of groundwater samples, chain of custody sheets and laboratory data sheets are attached with this report I SOIL SAMPLE COLLECTION On 29 April 1994, soil sampling activities were initiated at a location which was previously selected by representatives of San Joaquin County Environmental Health Division using site information provided by the City of Tracy The soil sampling activities were conducted using a hollow stem auger flight drilling rig provided by Spectrum Drilling Company and were witnessed by a representative of San Joaquin County Environmental Health Soil samples were collected using a California modified split spoon sampler containing three 2-inch by 6-inch long brass tubes Soil samples were collected at five foot intervals beginning from ground surface