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A conceptual layout of sandbeds on the site indicated that approximately 1.0 million gallons per day of <br /> treated wastewater could be discharged at the site based on the standard loading rate of 5 gallons per day <br /> per square foot(gpd/sf) over approximately 4.5 acres of the parcel. <br /> After the initial screening process, larger-scale loading tests were proposed to further evaluate the infiltration <br /> capacity of the site soils. The loading tests evaluated the site's infiltration capacity using thousands of <br /> gallons of water rather than a few gallons of water, as are used for percolation tests, with the goal of either <br /> considering a greater loading or a reduction in footprint size by allowing the higher loading rates. <br /> The Massachusetts Department of Environmental Protection (MassDEaccepted standard application rate <br /> for recharging effluent is 5 gallons per day per square foot (gpd/sf). The loading tests were established to <br /> determine whether this loading rate can be increased based on actual,site conditions, providing the project <br /> greater flexibility in either higher discharge volumes and/or smaller discharge footprint. <br /> 2 Field Investigation <br /> 2.1 Loading Tests <br /> Loading tests are essentially large-scale percolation 'tests. They are accomplished .by applying large <br /> quantities of water to basins with a specific surface area to:',allow 'the calculation of an'infiltration rate in <br /> minutes per inch and in gallons per day pcC square foot. The general protocol for completing loading tests is <br /> described in the USEPA Process Design Manual-Land Treatment of Municipal Wastewater(1981). <br /> 2.2 Test Preparation <br /> Two locations within the site-were � <br /> identified to serve as test locations. After <br /> the site was cleared, monitoring wells; <br /> were installed at the two test locations <br /> and at a third location to provide bas <br /> eline <br /> information (see boring logs;m Appendix <br /> A). Monitoring wells were drilled to a r <br /> depth of 16fe,0t,_below the wafer„table. <br /> The bottoms of�the wells were set with 10 <br /> feet of PVC screened pipe. The tops of � <br /> the wells were protected with steel <br /> casings. Test pits were then.;excav I din <br /> close proximity to each of the 'three <br /> monitoring wells to determine the depth to Empty test basin <br /> sandy materials free of loam and silt <br /> materials. Field reports for the test pits (included in Appendix B) indicate that medium sand was encountered <br /> between 26 and 64 inches. <br /> One 10-foot diameter basin was installed at each test location. Figure 1 is a site map showing the <br /> approximate locations of the test basins and monitoring wells. The basins served as the infiltration sites for <br /> the loading tests and the observation wells were used for monitoring the water table response to the <br /> 2 <br />