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A. Introduction <br />Additional work is necessary a the City of 0>ono property located at 1285 Brown Road <br />South because the full horizontal extern of groundwater contamination has not been defined <br />for the area downgradient of a former 3,000-gallon unleaded gasoline underground storage <br />tank (UST). Br^n Intertec observed the tank removal and performed the required sampling <br />and analysis activities. <br />Due to the expected request from the Minnesota Pollution Control Agency (MPCA) that long­ <br />term groundwater monitoring be performed at this site, costs and a tentative timetable for a <br />year of quarterly sampling have been included. <br />B. Scope of Work <br />Braun Intertec proposes the following scope of work to address the possible migration of <br />dissolved-phase petroleum groundwater contamination downgradient from the area of die <br />former 3,000-gallon unleaded gasoline UST: <br />• A Monitoring well permit will be obtained prior to drilling activities. <br />• Conducting two soil borings, at locations to the south of and parallel to Crystal <br />Avenue, across the street from the site (south of monitoring well MW-4). The borings <br />will be conducted to an approximate depth of 20 feet. <br />• Should additional borings be required due to the detection of soil organic vapors in the <br />two scheduled soil borings using the PID, charges will be assessed on a unit basis. <br />• Collecting soil samples at 2.5 foot vertical intervals using a split-spoon sampler. <br />• Field-screening soil samples for the presence of organic vapors using a photoionization <br />detector (PID). <br />• Collecting one soil sample from the boring which indicates petroleum contamination <br />based on FID Jar-headspace readings. The soil sample will be collected from the <br />inter\'al where the highest PID Jar-headspace reading was recorded above the water <br />table. Should both borings indicate 'clean' conditions based on field readings, the soil <br />sample will be collected from one of the borings from the interval directly above die <br />apparent water uble. The soil sample will be analyzed for benzene, ethylbenzene, <br />toluene and xylenes (BETX), methyl tertiary butyl ether (MTBE), gasoline range <br />organics (GRO), orthophosphate as phosphorous, total phosphorous and total kjeldahl <br />nitrogen (TKN).