o Document the installation of groundwater observation wells, 



o Conduct and monitor in-situ falling head permeability 

 tests. 



As previously discussed, the project area east of the existing 

 brick wall, which divides the site in a north-south direction, 

 was inaccessible at the time of the exploration program and no 

 borings could be conducted within the area. During 

 explorations for final design, additional borings must be 

 conducted in this area to characterize the subsurface 

 conditions . 



2-03. GROUNDWATER OBSERVATION WELLS 



Groundwater observation wells were installed in completed 

 boreholes B102, B103 and B104. *The bottoms of the of the well 

 tips were installed to depths of approximately 15 to 20 ft. 

 below ground surface. The relationship of the well screen to 

 the major soil strata is shown in the groundwater installation 

 reports included as part of Appendix C. 



The observation wells consist of 2.0 in. I.D. machine slotted 

 PVC wellpoints installed from the bottom of the well to 

 approximately ground surface. The top of each observation well 

 was provided with a concrete/bentonite seal and was encased in 

 a protective roadway box. Groundwater levels measured during 

 periodic monitoring of the observation wells, between the 

 period 29 March to 4 May 1988, are included in Appendix C. 

 The corresponding tide level recorded at the time of the 

 groundwater measurements is also contained in the monitoring 

 reports. 



2-04. IN-SITU PERMEABILITY TESTS 



A preliminary field permeability testing program was undertaken 

 to better evaluate the effects of a permanent underslab 

 drainage system on the groundwater levels in the area and to 

 assess the feasibility and type of seepage cut-off needed to 

 construct the proposed below grade parking area. The testing 

 program consisted of performing two falling head permeability 

 tests in the glacial till soil in borehole B103. The location 

 of the tests with respect to the soil stratigraphy is shown on 

 the Subsurface Profile A-A included as Figure 3 and the field 

 test data are included as Appendix D. 



Field permeability tests were typically conducted according to 

 the following procedure; 



AQK 



OC 76 



