COMPLIANCE INFO 1987-2003 - Laserfiche WebLink

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V Z1 INC component). This measurement is linearly related to the terrain conductivity which can assist in finding subtle geophysical anomalies associated with objects such as backfilled trenches. The inphase electromagnetic component is a ratio of the induced secondary ' magnetic field to the primary magnetic field, which results in a significant increase in sensitivity to metallic objects such as buried pipelines and underground fuel storage tanks. 3.2 Survey Methods After a brief reconnaissance of the site, a local coordinate system was established for the entire area. This was accomplished using a Pentax PX-06D theodolite and electronic distance measurement instrument along with field tape measures. An origin of 1000 feet north and 1000 feet east was established approximately 15 feet northeast of the intersection of Sacramento Street and Oak Avenue. The survey area was marked with white paint on the ground The electromagnetic measurements were acquired with the instrument boom oriented in 1 east-west and north-south configurations. Data measurements were collected on ten foot centers. Approximately 1,250 individual measurements were collected. Magnetic measurements were acquired at the rate of 10 samples per second (0.25 feet per 4 sample) along each east - west oriented profile (five foot separation between each profile). The instrument operator walks along each profile and then at designated intervals of 20 feet, event markers are imposed onto the data file. These event markers are used in processing to linearly interpolate the data and assign coordinates to each data sample. Approximately 40,000 individual magnetic measurements were collected during the survey. The pipe and cable locator was also used to determine where any pipelines exist within the survey area. This was helpful to determine the source of some anomalies. � E 05300010.001 4